GetAhead!BasicSciences

500SBAs

PriyaJeevananthanObstetricandGynaecologyRegistrarQueenCharlotte’sandChelseaHospital,London

AnnaKowalewskiFoundationDoctor,London

SeriesEditor

SaranShantikumarAcademicClinicalFellowinPublicHealthUniversityofWarwickCoventry,UK

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Contents

PrefaceContributors

QuestionsPaper1

AnswersPaper1

QuestionsPaper2

AnswersPaper2

QuestionsPaper3

AnswersPaper3

QuestionsPaper4

AnswersPaper4

QuestionsPaper5

AnswersPaper5

QuestionsPaper6

AnswersPaper6

QuestionsPaper7

AnswersPaper7

QuestionsPaper8

AnswersPaper8

QuestionsPaper9

AnswersPaper9

QuestionsPaper10

AnswersPaper10

Index

Preface

WelcometoGetAhead!BasicSciences:500SBAs.ThebookcontainsacollectionofSBAstohelpyoupracticeforyourBasicSciencesexam,covering

topicsinanatomy,physiology,pharmacologyandbiochemistry.Inadditiontotestingcoreknowledge,thequestionsalsoencompassimportantproblemsthatarerelevanttoclinicalpractice.

Practice questions are the bestway of reinforcing knowledge and give you a realistic idea of howeffective your revision is. As you draw closer to your exam, it is important to do as many practicequestionsasyoucaninorder tofamiliarizeyourselfwiththethoughtprocessandtodowholepracticepaperssoyoupaceyourselfcorrectlyontheactualdayoftheexam.Themorequestionsyoudo,themoreyouwillbegintoseethecommonthemesandpatternsthatareeasymarkstopickupintheexam,whichcanbethedifferencebetweenapassandafail.

We have divided this book into 10 papers, each consisting of 50 questions with detailed answerssupplied at the end of each paper. Explanations have been provided to help you understand the rightanswer andwhy the other options are not correct. You should aim to take 60minutes on each paper,leavingyouaroundaminuteforeachquestion.

We hope this book, and its companion volumeGet Ahead! Basic Sciences: 100 EMQs, helps youprepare,andmostimportantlypass,yourexams!Bestoflucktoyouandremembertopractice,practice,practice!

PriyaJeevananthanAnnaKowalewski

Contributors

WRITTENANDEDITEDBYPriyaJeevananthanAnnaKowalewski

ADDITIONALCONTRIBUTORSNeelSharmaAvishekDasDanielGlassmanPavithraLogitharajahChineduMaduakorVikramMalhotraIanMannJohnNehmeNaomiPeriselmerisDonnaPilkingtonJamesRichardsonRavnitaSharmaNarenSrinivasanStephanieStoneHelenButler

SERIESEDITORSaranShantikumar

QuestionsPaper11.TheEdinger–Westphalnucleusisassociatedwithwhichofthefollowingcranialnerves?

A. CNIII

B. CNIV

C. CNVII

D. CNIX

E. CNX

2.Whichofthefollowingcausesanincreasedaniongap?

A. Diabeticketoacidosis

B. Diarrhoea

C. Hyperventilation

D. Hypoventilation

E. Vomiting

3.Whichofthefollowingmusclesarenotusedinrespiration?

A. Diaphragm

B. Intercostalmuscles

C. Pectoralmuscles

D. Scalenemuscles

E. Sternocleidomastoidmuscles

4.Whatarethecaudatenucleus,putamenandglobuspalliduscollectivelyknownas?

A. Basalganglia

B. Cerebellum

C. Diencephalon

D. Frontallobe

E. Neostriatum

5.Withinwhichlobeofthebrainistheprimaryauditorycortexsituated?

A. Frontal

B. Frontoparietal

C. Occipital

D. Parietal

E. Temporal

6.Whatlieswithinthesellaturcicaofthesphenoidbone?

A. Amygdala

B. Cerebellarpeduncle

C. Mammillarybodies

D. Pituitarygland

E. Pons

7.Whichofthefollowingdrainsdirectlyintotheportalvein?

A. Leftandrightgastricveins

B. Leftgastroepiploicvein

C. Rightgastroepiploicvein

D. AlloftheoptionsAtoC

E. NoneoftheoptionsAtoC

8.Pyruvateisconvertedviapyruvatecarboxylasetowhat?

A. Acetyl-CoA

B. Citrate

C. Oxaloacetate

D. Oxoglutarate

E. Succinate

9.Whichoneofthefollowingstatementsregardinghaemoglobinmetabolisminhumansisnottrue?

A. Ageingordamagedredbloodcellsareremovedfromthecirculationbymacrophagesofthespleen,liverandbonemarrow.

B. Bilirubinisboundtoglucuronicacidintheliverandkidneybytheenzymeglucuronyltransferase.

C. Conjugatedbilirubinisexcretedinbileandentersthesmallintestine.

D. Globinisseparatedfromhaemandthenconvertedtobilirubin.

E. Ifthereisincreasedredcellturnover,bilirubinandurobilinogenexcretionincreases.

10.Severevomitingwillleadtowhichacid–basedisturbance?

A. Metabolicacidosis

B. Metabolicalkalosis

C. Nodisturbance

D. Respiratoryacidosis

E. Respiratoryalkalosis

11.Carbimazoleiswithinwhichclassofdrugs?

A. β-Adrenoceptorantagonists

B. Glucocorticoids

C. Iodides

D. Radioiodine

E. Thioureylenes

12.Whichbiochemicalmarkerismostcommonlyraisedinrhabdomyolysisandmusculardystrophy?

A. Alanineaminotransferase

B. Amylase

C. BenceJonesproteins

D. Creatinine

E. Creatinephosphokinase

13.Whichofthefollowingterminatestheactivityofnoradrenalineatthesynapticcleft?

A. Acetylcholinesterase

B. Catechol-O-methyltransferase

C. Dopa-decarboxylase

D. GlutamatecarboxypeptidaseII

E. Lipase

14.Whichmuscleistheantagonistofelbowflexion?

A. Bicepsbrachii

B. Brachialis

C. Pronatorteres

D. Trapezius

E. Tricepsbrachii

15.Theaccommodationreflexoftheeyeisregulatedbytheautonomicnervouscontrolofwhichofthefollowingmuscles?

A. Ciliarymuscleoftheeye

B. Inferiorobliquemuscleoftheeye

C. Müllermuscles

D. Orbicularisoculimuscles

E. Superiorobliquemuscleoftheeye

16.Preganglionicneuronsofthesympatheticdivisionthatinnervatethestomach,liverandsmallintestinepassthroughwhichofthefollowingganglia?

A. Coeliacganglion

B. Inferiormesentericganglion

C. Pelvicganglion

D. Superiorcervicalganglion

E. Superiormesentericganglion

17.Whichofthefollowingisnotatypeofwhitebloodcell?

A. Basophil

B. Eosinophil

C. Monocyte

D. Polymorphonuclearneutrophil

E. Thrombocyte

18. How much energy is contained in a phosphate-to-phosphate bond in a molecule of adenosinetriphosphate?

A. 14.2kJ/mol

B. 18.2kJ/mol

C. 30.5kJ/mol

D. 40.5kJ/mol

E. 45.5kJ/mol

19.Noradrenalineactsoncardiacmuscletostimulateheartrateandforceofcontractionviawhichofthefollowingreceptors?

A. α-Adrenergicreceptors

B. α2-Adrenergicreceptors

C. β-Adrenergicreceptors

D. Bothβ-andα-adrenergicreceptors

E. Noneoftheabove

20.Whichmuscleissuppliedbythelongthoracicnervetorotatethescapula?

A. Deltoid

B. Latissimusdorsi

C. Levatorscapulae

D. Serratusanterior

E. Teresmajor

21.WithinwhichlayerofthegastrointestinaltractisAuerbach’splexusfound?

A. Laminapropria

B. Muscularisexterna

C. Muscularismucosa

D. Serosa

E. Submucosa

22.Caseousnecrosiscanbeseenhistologicallyinwhichofthefollowingconditions?

A. Ankylosingspondylitis

B. Coloniccarcinoma

C. Hepatitis

D. Lupusglomerulonephritis

E. Tuberculosis

23.Whichofthefollowingisacommoncauseofnecrotizingfasciitis?

A. Corynebacteriumsp.

B. Listeriamonocytogenes

C. Mycobacteriumsp.

D. Nocardiaasteroides

E. Streptococcuspyogenes

24.Bronchoconstrictionofthebronchialtreeiscausedbywhichofthefollowing?

A. Parasympatheticinnervationviathephrenicnerve

B. ParasympatheticinnervationviaT3–T6

C. Parasympatheticinnervationviathevagusnerve

D. SympatheticinnervationviaT3–T6

E. Sympatheticinnervationviathevagusnerve

25.AngiotensinIIreceptorantagonistsarecontraindicatedinwhichofthefollowingpatients?

A. Patientsalreadyonanangiotensin-convertingenzymeinhibitor

B. Patientsonpotassium-sparingdiuretics

C. Patientswhosufferedacoughwithramipril

D. Patientswithbilateralrenalarterystenosis

E. Patientswithmicroalbuminuria

26.Whichoneofthefollowingstatementsregardingoxygentransportandhaemoglobinisfalse?

A. Asinglehaemoglobinmoleculecancarryuptofourmoleculesofoxygen.

B. Eachhaemoglobinmoleculecontainsfourglobinchainsandfourhaemunits,eachwithfouratomsofiron.

C. Haemoglobinbindsreversiblytooxygentoformoxyhaemoglobin.

D. Haemoglobincontainsglobinandapigmentediron-containingcomplex.

E. Inthelungsoxyhaemoglobinformationisfavouredtodissociation.

27.Whichofthefollowingoptionsregardingtheaetiologyofpolycystickidneydiseaseiscorrect?

A. Autoimmune:anti-glomerularbasementmembrane(anti-GBM)antibodies

B. Genetic:autosomaldominant

C. Genetic:X-linkedrecessive

D. Infective:schistosomiasis

E. Inflammatory:drug-induced

28.Whichofthefollowingisincorrectwithregardtonecrosis?

A. Cellsswellinsize.

B. Itaffectslargegroupsofcells.

C. Itisaninflammatoryresponse.

D. Itiscausedbyirreversibleinjury.

E. Thereisperipheralcondensationofchromatin.

29.Whichoneofthefollowingmedicationsisusedinbenignprostatichyperplasiatoreduceprostatesizebyinhibitingthemetabolismoftestosterone?

A. Doxazosin

B. Finasteride

C. Metoprolol

D. Spironolactone

E. Tamsulosin

30.Whichofthefollowingbestdescribestheactionofthemusclerelaxantsuxamethonium?

A. Itblockscalciumionchannelsattheneuromuscularjunction.

B. Itcanbereversedbyanticholinesterases.

C. Itisanon-depolarizingneuromuscularblocker.

D. Itisanacetylcholinesteraseinhibitor.

E. Itmimicsacetylcholineattheneuromuscularjunctions.

31.Whichofthefollowingisadrugusedtoimprovethesymptomsofmyastheniagravis?

A. Atenolol

B. Baclofen

C. Mirtazapine

D. Pyridostigmine

E. Suxamethonium

32.Parasympatheticinnervationtotheheartreducestheforceofcontractionviawhichnerve?

A. Accessorynerve

B. Glossopharyngealnerve

C. Intercostalnerves

D. Phrenicnerve

E. Vagusnerve

33.Whichofthefollowingismostappropriateforthetreatmentofnocturnallegcramps?

A. Co-proxamol

B. Morphine

C. Oramorph

D. Paracetamol

E. Quinine

34.Whichofthefollowinganticoagulantscanbemonitoredbymeasuringtheactivatedpartialthrombintime?

A. Aspirin

B. Clopidogrel

C. Dipyridamole

D. Heparin

E. Warfarin

35.DuringtheconversionofmalatetooxaloacetateintheKrebscycle,amoleculeofwhatisformed?

A. CO2

B. GTP

C. H2

D. H2O

E. NADH

36.Whichofthefollowingisincorrectwithregardtoapoptosis?

A. Cellsshrinktoformapoptoticbodies.

B. ItcanbetriggeredbyDNAdamage.

C. Itisalsoknownasprogrammedcelldeath.

D. Itisassociatedwithspecificgeneactivation.

E. Itusuallyaffectslargegroupsofcells.

37.WithregardtotheABOsystemofbloodgrouping,whichoneofthefollowingisincorrect?

A. BloodgroupA,asadonor,isincompatiblewithonlybloodgroupB.

B. BloodgroupAB,asadonor,isincompatiblewithA,BandO.

C. BloodgroupABistheuniversalrecipient.

D. BloodgroupB,asadonor,iscompatiblewithBandAB.

E. BloodgroupOistheuniversaldonor.

38.Whichofthefollowingdrugsdoesflumazenilreverse?

A. Atracurium

B. Atropine

C. Diazepam

D. Methadone

E. Morphine

39.Malignanthyperpyrexiaisprecipitatedbywhichofthefollowingagents?

A. Diazepam

B. Prilocaine

C. Propofol

D. Suxamethonium

E. Thiopental

40.Whichofthefollowingorganismsisnotusuallyfoundinthesputumofapatientwithcysticfibrosis?

A. Burkholderiacepacia

B. Haemophilusinfluenzae

C. Legionellapneumophila

D. Pseudomonasaeruginosa

E. Staphylococcusaureus

41.Onwhich chromosome is the gene for the defective protein for the cystic fibrosis transmembraneconductanceregulatorcoded?

A. Chromosome7

B. Chromosome8

C. Chromosome9

D. Chromosome10

E. Chromosome11

42.Whichofthefollowingisasignofdigoxintoxicity?

A. Blurredvisionandxanthopsia

B. Gynaecomastia

C. Hypokalaemia

D. Hypercalcaemia

E. Reversedtickpatternontheelectrocardiogram

43.Fromwhichtypeofcelldoesacarcinoidtumourdevelop?

A. Enterocyte

B. Enteroendocrinecells

C. Gobletcells

D. Panethcells

E. Stemcells

44.Whichofthefollowingprovidesarterialsupplytothelessercurvatureofthestomach?

A. Leftgastricartery

B. Leftgastroepiploicartery

C. Rightandleftgastricarteries

D. Rightgastricartery

E. Rightgastroepiploicartery

45.Whichofthefollowingdysfunctionaltumoursuppressorgenesisinvolvedincolorectalcancer?

A. APC

B. BRCA1

C. NF1

D. p53

E. RB1

46.Whichofthefollowingdrugsmaycauseadrycough?

A. AngiotensinIIreceptorantagonists

B. Angiotensin-convertingenzymeinhibitors

C. β-Blockers

D. Calciumchannelblockers

E. Potassiumchannelblockers

47.Whichofthefollowingbestdescribesthepathogenesisofmyastheniagravis?

A. Adefectinthemyosinfilamentsofskeletalmuscle

B. Demyelinationofmotorneurons

C. Destructionoftheneuromuscularjunctionbydemyelinatingdisease

D. Presenceofautoantibodiesagainsttheacetylcholinereceptorsattheneuromuscularjunction

E. Reducednumberofmotorend-plates

48.Whichofthefollowingisnotassociatedwithirreversiblecellinjury?

A. Celldeath

B. Densebodyformationwithinmitochondria

C. Dissociationofribosomes

D. Nucleardegeneration

E. Releaseofcellularenzymes

49.Whichofthefollowingdysfunctionaltumoursuppressorgenesisinvolvedinovariancancer?

A. APC

B. BRCA1

C. NF1

D. p53

E. RB1

50.Whichofthefollowingisindicatedforthetreatmentofneuropathicpain?

A. Amitriptyline

B. Baclofen

C. Co-proxamol

D. Diclofenac

E. Paracetamol

AnswersPaper11.A–CNIIIOculomotor, facial, glossopharyngeal and vagus nerves have axons that originate from preganglionicneurons, which synapse at their respective terminal ganglia. Oculomotor (CN III) preganglionicparasympathetic neurons originate from the Edinger–Westphal nucleus and end in the ciliary ganglion.Postganglionicneurons travel in shortciliarynerves tosupply thesphincterpupillaemuscleof the iris(whichcausespupilconstriction)andtheciliarymuscles(whichchangetheshapeofthelens).Theseplayakeyroleinthepupillarylightreflexandaccommodation.

2.A–DiabeticketoacidosisThe anion gap is the difference between themeasured cations (Na+ andK+) and anions (chloride andbicarbonate).Thepathologicalpresenceofadditionalunmeasuredanions,withaconcurrentreductioninchlorideorbicarbonateconcentrations,will result inan increasedaniongap.Forexample, indiabeticketoacidosis,water-solubleketonesareproducedasaby-productoffattyacidmetabolism.Ketonesarealsoanionsandwillbebufferedbyareductioninbicarbonate,thusresultinginanincreasedaniongap.The other conditions listedwill cause somedegree ofmetabolic disturbance butwill not increase theaniongap.

3.C–PectoralmusclesTheprincipalmusclesofrespiration include thediaphragmandthe intercostalmuscles.Thediaphragmcontracts, enlarging the thoracic cavity and decreasing intrathoracic pressure. This draws air into thelungsviathepressuregradient.Asthediaphragmrelaxes,theinherentelasticrecoiloflungtissuepushesairout.Theexternalintercostalscontractduringinspirationwhiletheinternalandinnermostintercostalshave a role to play in forced expiration.The scalene and sternocleidomastoidmuscles are considered‘accessory’muscleswhichareusedduringforcedbreathingorinpathologicalstates.Thepectoralgroupofmusclesarenottypicallyclassedasrespiratoryoraccessorymuscles.

4.A–BasalgangliaThecaudatenucleus,putamenandglobuspallidusareanatomicallyandfunctionallycloselyrelated,andarecollectivelyknownasthebasalganglia.Theyareresponsibleforpostureandmovement.

5.E–TemporalThe primary auditory cortex is found within the superior temporal gyrus of the temporal lobe. Themajorityof thefunctionalzone is in thesuperiorbankof thegyrusand it isnormallyhiddenwithin thelateral fissure. There is a small transverse temporal gyrus (or Heschl’s convolution) which is anindicationoftheprecisesiteoftheauditorycortex.

6.D–PituitaryglandThepituitarygland lieswithin thesella turcicaandconsistsof twocytologicallydifferentparts,whicharetheposteriorpituitary(neurohypophysis)andtheanteriorpituitary(adenohypophysis).Thepituitaryglandisheldbythepituitarystalk,or infundibulum,andliescaudal totheopticchiasm.If thepituitary

becomes flattenedor shrinks, for instance due to intracranial hypertensionor pituitary pathology, it nolongeroccupiesthesellaturcica.Thisisknownasemptysellasyndrome.

7.A–LeftandrightgastricveinsOnlytheleftandrightgastricveinsdirectlydrainintotheportalvein.Therightandleftgastroepiploicveins drain into the portal vein indirectly via the superior mesenteric vein and the splenic vein,respectively.

8.C–OxaloacetatePyruvateismetabolizedbypyruvatedehydrogenasetoformacetyl-CoA.Pyruvatecanalsobeconvertedbypyruvatecarboxylasetooxaloacetate,whichisanimportantintermediaryinthetricyclicacid(TCA)cycle.Acetyl-CoAisatwo-carboncompoundthatbindswiththefour-carbonoxaloacetatetoformcitrate–areactionthatiscatalysedbycitratesynthase.Citrateisthenconvertedtoanintermediatecis-aconitate(via the enzyme aconitase) by removing awatermolecule. cis-Aconitate is furthermetabolized by theaconitase and is converted to isocitrate by adding a water molecule. Isocitrate is still a six-carboncompoundbutithasbeenstructurallyalteredbytheremovalandadditionofawatermolecule.Thesix-carbonmoleculeofisocitrateiscatalysedbytheenzymeisocitratedehydrogenasetoformthefive-carboncompoundoxoglutarate.Duringtheconversionofisocitratetooxoglutarate,onemoleculeofNADHandonemoleculeofCO2areformed.

9. B – Bilirubin is bound to glucuronic acid in the liver and kidney by the enzyme glucuronyltransferaseGlucuronyl transferase is found in the liver (butnot in thekidney).Thisenzyme thusbindsbilirubin toglucuronicacidintheliveronly.

10.B–MetabolicalkalosisSeverevomitingleadstothelossofhydrogenionsandotherelectrolytes.Thiscanresultinametabolicalkalosis for two reasons: firstly through the direct loss of hydrogen ions, and secondly through theincreased reabsorption of potassium ions in the kidney, at the expense of hydrogen, to address theelectrolyteimbalance.

11.E–ThioureylenesBoth carbimazole and propylthiouracil are thioureylenes. Thioureylenes are used in the treatment ofhyperthyroidism.Theyare thought toactby inhibiting tyrosineresidue iodinationon thyroglobulin, thusreducingthyroidhormonesynthesis.

12.E–CreatinephosphokinaseCreatine phosphokinase is used as amarker ofmuscle damage. This enzyme catalyses the reaction ofcreatine andATP to phosphocreatine andADP.Phosphocreatine acts as an intramuscular energy store.Circulatingcreatinephosphokinaselevelsareelevatedinrhabdomyolysis(breakdownofskeletalmuscle)andmusculardystrophy,aswellasinpost-myocardialinfarctionstates,myocarditisandmyositis.

13.B–Catechol-O-methyltransferaseCatechol-O-methyltransferase (COMT) is one of several enzymes responsible for degrading thecatecholaminesnoradrenalineandadrenaline.Thisenzymeisintracellularandfoundinthepostsynapticneurons.COMTinhibitorsareusedcommonlyinthetreatmentofParkinsondisease,wheretheypreventthebreakdownoftherapeuticlevodopabyCOMT.

14.E–TricepsbrachiiIn this context, an antagonist is amuscle that opposes a specificmovement. Elbow flexion is broughtaboutbycontractionofbrachialis andbicepsbrachii.Tricepsbrachii is theantagonist andcontractionresults in theoppositemovement (i.e. elbowextension).Theanconeusmuscle also assistswith elbowextension, although its relative contribution to this action is trivial.When onemuscle in the agonist–antagonistpairiscontracted,theotherisrelaxed,andviceversa.

15.A–CiliarymuscleoftheeyeAccommodation is the ability for the eyes to focus upon a nearbyobject via convergence of the opticaxes.Thisinvolvescontractionoftheciliarymuscleswhichresultsinanincreasedconvexityofthelens.The accommodation reflex, which is under the control of the Edinger–Westphal nucleus, combinesaccommodation and convergence with pupil constriction (miosis). While pupillary convergence isnecessarytopreventdiplopia,thefunctionalrequirementformiosisisunknown.

16.A–CoeliacganglionThecoeliacgangliaarepartof thesympatheticprevertebralchainandcontribute to thecoeliacplexus.The coeliac plexus is the largest nerve plexus and surrounds the coeliac trunk, superior mesentericarteries and renal arteries at their origin. It is located at the levelofT12andL1.Secondaryplexusesbranchingoutfrom,orconnectedto,thecoeliacplexusaredistributedtotheupperabdominalorgans(e.g.liver,gallbladder,stomach,spleen,pancreas,smallbowelandproximaltwo-thirdsofthelargebowel).

The coeliac plexus is alsoknownas the solarplexus due to the spicule-like radiation of its nervefibres.

17.E–ThrombocyteBasophils, monocytes, eosinophils and polymorphonuclear neutrophils are all different types of whitebloodcellandplayapartininfectionandtheimmunesystem.Thrombocytesarenotwhitebloodcells–theyareplatelets,whichareinvolvedintheregulationofbloodclotting.

18.C–30.5kJ/molIncells,reactionsthatdirectlyproduceandconsumeenergyarenotlinked.Thereforeit isnecessarytohaveashort-termmethodofstoringenergywithinthecells.Themoleculeadenosinetriphosphate(ATP)istheuniversalenergystore.ATPismadeupofadenineandaribosesugargroup,whichtogetherformadenosine,andthreephosphategroups.Theenergystoredinthephosphate-to-phosphatebondishighat30.5 kJ/mol. However, the energy stored in the sugar-to-phosphate bond in adenosinemonophosphate(AMP) ismuch lower at 14.2 kJ/mol,which iswhy it is not used as an energy source formetabolicreactions.

19.C–β-AdrenergicreceptorsIncreased sympathetic stimulation promotes catecholamine secretion (noradrenaline and adrenaline) bythe adrenal medulla, resulting in an increased heart rate and force of contraction, and peripheralvasoconstriction.Noradrenalineactsonβ-adrenergicreceptors in theheart.Thisexplains theuseofβ-blockers,suchasatenolol,inslowingtheheartrate.

20.D–SerratusanteriorSerratus anterior is supplied by the long thoracic nerve (C5–C7).Damage to the long thoracic nerve,which can occur during axillary surgery, results in winging of the scapula. A winged scapula can bedemonstratedbyaskingthepatienttopushagainstawallwithbotharms.

21.B–MuscularisexternaAuerbach’splexusispartoftheentericnervoussystem.Itisfoundbetweenthelongitudinalandcircularlayers of the muscularis externa. It provides both sympathetic and parasympathetic input to thegastrointestinaltract.

22.E–TuberculosisMycobacterium tuberculosis is an acid-fast bacillus which causes tuberculosis. Its granulomatouslesionsconsistofLanghansgiantcellswithacentralareaofcaseousnecrosis.Caseousnecrosis is sonamed due to its apparent soft andwhite ‘cheese-like’ appearance. It can also be seenwith syphilis,histoplasmosisandCryptococcusinfections.

23.E–StreptococcuspyogenesNecrotizing fasciitis is a subcutaneous infectionmost commonly causedbyβ-haemolytic streptococcus(e.g. Streptococcus pyogenes). However, methicillin-resistant Staphylococcus aureus (MRSA),Clostridium perfringens and Bacteroides fragilis can also cause this destructive, life-threateninginfection.Necrotizingfasciitisisafulminantdeepinfectionwithahighmortalityrate.Itspreadsrapidly,causingmassive tissue destruction.Urgent debridement, fasciotomy and aggressive antibiotic treatmentarerequired.

24.C–ParasympatheticinnervationviathevagusnerveVagalparasympatheticneuronsoriginatefromthedorsalmotornucleusofthevagus,whichissituatedinthe medulla underneath the floor of the fourth ventricle. From here they travel to the cardiovascular,respiratoryandgastrointestinalsystems.Intherespiratorysystem,theycausebronchoconstrictionofthebronchialtree.

25.D–PatientswithbilateralrenalarterystenosisPatients with bilateral renal artery stenosis become dependent on the renin–angiotensin–aldosteronesysteminordertomaintainrenalperfusion.Ifeitheranangiotensin-convertingenzyme(ACE)inhibitororangiotensin-receptor blocker (ARB) is employed in the treatment of their hypertension, you willessentiallycompleteachemicalnephrectomy.ACEinhibitorsandARBscanbeusedtogether,understrictguidance,forthetreatmentofheartfailureandalsohypertension.

26.B–Eachhaemoglobinmoleculecontainsfourglobinchainsandfourhaemunits,eachwithfouratomsofironEachhaemoglobinmoleculecontainsfourglobinchainsandfourhaemunits,eachwithoneatomofiron.Whenoxygenlevelsarelow,oxyhaemoglobinbreaksdownliberatingoxygentothetissues.Whenoxygenlevelsarehigh,astheyareinthelungs,oxyhaemoglobinformationisfavoured.

27.B–Genetic:autosomaldominantPolycystickidneydisease(PKD)isthemostcommoninheritednephropathyintheWesternworldandislargelyinheritedinanautosomaldominantfashion.It ischaracterizedbythepresenceofmultiplerenalcystsandleadstoprogressiverenalfailure.Acuteepisodescanoccurandpresentwithhaematuriaandloinpain.Associatedpathologies includehypertension,subarachnoidhaemorrhage(owingtoruptureofberry aneurysms), hepatic cysts and renal calculi.Autosomal recessivePCKD is far less commonandmoreclinicallyserious,withunderdevelopedkidneysanda30%deathrateinnewborns.

28.E–Thereisperipheralcondensationofchromatin

Necrosis is the premature death of cells secondary to external factors, such as hypoxia, infection ortrauma.Ittendstoaffectclustersofcellswhichareexposedtothesametrigger,andisassociatedwithaninflammatoryresponse.Peripheralcondensationofchromatinisafeatureofapoptosis.

29.B–FinasterideBenign prostatic hyperplasia (BPH) is a non-malignant increase in prostate size,which is common inoldermen.About25–50%ofmenagedover65willhavesomedegreeofsymptomaticBPH.Symptomsaregroupedundertheumbrellaterm‘prostatism’andareadirectresultofurinaryoutletobstruction.Theyincludehesitancy,poor stream, terminaldribblingand frequency.Drug treatmentsmostcommonlyusedareα-adrenergicblockers(e.g.doxazosinandtamsulosin)and5α-reductaseinhibitors(e.g.finasteride).The former acts as smooth muscle relaxants, relieving obstructive symptoms, and the latter inhibitsprostatictestosteronemetabolism,thusreducingprostatesize.

30.E–ItmimicsacetylcholineattheneuromuscularjunctionsSuxamethoniumisadepolarizingneuromuscularblocker.Ithasarapidonsetandshortdurationofaction,andsoisusedforshort-termparalysisbeforesurgerytoallowintubation.Respirationmustbeassistedorcontrolledwhen using neuromuscular blockers. Suxamethonium acts bymimicking acetylcholine at theneuromuscular junction (NMJ), thus resulting in neuromuscular blockade by competitive antagonism.Unlike the non-depolarizing neuromuscular blockers, the actions of suxamethonium cannot be reversedwithacetylcholinesteraseinhibitors;infacttheypotentiatetheblockade.Recoveryfromsuxamethoniumisspontaneous.

31.D–PyridostigmineMyasthenia gravis is an autoimmune disorder in which autoantibodies block acetylcholine (ACh)receptors on the post-synapticmembrane of the neuromuscular junction (NMJ). This results inmusclefatigability,whichcanbeshownasadecrement inevokedmusclepotentialonrepetitivemotorneuronstimulation.Theextraocularmusclesarefrequentlyaffected,resultingindiplopiaandptosisinadditiontobulbar and proximal muscle involvement. About 90% of patients have some degree of thymicinvolvement,suchashyperplasiaorathymoma,andthymectomyisaneffectivetreatmentinsomecases.Medical treatment iswithacetylcholinesterase inhibitors (e.g.pyridostigmineorphysostigmine),whichinhibitAChmetabolismandthusincreaseitsavailabilityfortransmissionattheNMJ.

32.E–VagusnerveThe parasympathetic division of the autonomic nervous system does not exhibit a ‘flight or fight’response; indeed, it results in a ‘rest or digest’ response. The vagus nerve provides parasympatheticinnervation to the heartwhere it results in negative inotropic and negative chronotropic effects (i.e. itdecreasestheforceofcontractionandtheheartrate).

33.E–QuinineQuininesaltsareeffectiveatreducingthefrequencyofnocturnallegcrampsbyabout25%inambulatorypatients. It takes up to 4 weeks before any discernible improvement is noted. Treatment should beinterruptedevery3monthstoassesswhetherthereisacontinuedneedforquininetreatment.Quininewasprimarilyusedinthetreatmentofmalaria,althoughitisnolongerthefirst-linetherapy.

34.D–HeparinHeparinisarelativelyshort-actingintravenousanticoagulant.Ithasonemajorbeneficialpropertyoverotheranticoagulantsinthatreversalofitseffectscanbeeasilyandrapidlyachieved.Themajorproblemwithheparin is the requirement to regularly check the activatedpartial thromboplastin time (APTT) to

ensure therapeutic anticoagulation is being achieved. APTT is a measure of the intrinsic coagulationsystem.

35.E–NADHFumarateisafour-carboncompoundanditisanintermediarymoleculeinthecitricacid(Krebs)cycle.Fumarate ismetabolized by the enzyme fumarate hydratase to form the four-carbon compoundmalate.During this reaction, a singlewatermolecule is required.Malate ismetabolizedby theenzymemalatedehydrogenase,whichconvertsmalatetooxaloacetate.Duringtheconversionofmalatetooxaloacetate,amoleculeofNADHisformed.Oxaloacetateisafour-carboncompoundandiscombinedwithacetyl-CoAviatheenzymecitratesynthasetoformthesix-carboncompoundcitrate.

36.E–ItusuallyaffectslargegroupsofcellsApoptosis is programmed cell death, where a sequence of events results in cellular changeswith theeventual result of cell death. Theremay be an underlying increase in the expression of pro-apoptoticgeneswithinthecell.Apoptosisusuallyaffectssinglecellsincontrasttonecrosis,whichusuallyaffectsclustersofcells.

37.A–BloodgroupA,asadonor,isincompatiblewithonlybloodgroupBBloodgroupA,asadonor,isincompatiblewithBandO,becausebothmakeanti-AantibodiesthatwillreactwithAantigens.

38.C–DiazepamFlumazenil reverses the effects of benzodiazepines, such as diazepam, by acting as a competitiveantagonist.Itisanimidazobenzodiazepineandbearsacloseresemblancetothestructureofmidazolam.Ithas a half-life of approximately 50 minutes and is metabolized to a carboxylic acid derivative andglucuronide.

39.D–SuxamethoniumMalignanthyperpyrexiaisamyopathicdisorderthatischaracterizedbyamarkedincreaseinmetabolicrate. It is an autosomal dominant condition that can be precipitated by suxamethonium and volatileanaestheticagents.Theseagentstriggeranabnormalreleaseofcalciumfromthesarcoplasmicreticuluminto the cytoplasm. Symptoms include a rapid rise in temperature, progressive tachycardia, musclerigidityandmasseterspasm.

40.C–LegionellapneumophilaLegionellapneumophila is theGram-negativebacterium responsible forLegionnaires’disease and isnot usually found in the sputum of cystic fibrosis patients. Patientswith cystic fibrosis are commonlycolonized withHaemophilus and Streptococcus in their early years but are subsequently colonizedparticularlywithPseudomonasandalmostinvariablywithBurkholderia.

41.A–Chromosome7Thedefectiveproteingeneispresentonthelong(q)armofchromosome7.Itcodesforthecysticfibrosistransmembrane conductance regulator (CFTR) – a cyclic adenosinemonophosphate (cAMP) regulatedchlorinechannelwhich leads toahighconcentrationof sodiumanda lowconcentrationofchloride inexocrinesecretions.Therearemanyvariantsofthisdefect.ThemostcommonmutationistheΔF508:‘Δ’means a deletion, specifically in this case, of the three nucleotides coding for phenylalanine (F) atposition508ofthegene.Thisaccountsforupto70%ofallmutations.

42.A–BlurredvisionandxanthopsiaAreversedtickpatternonanECG(downward-slopingSTsegments)isnotasignofdigoxintoxicity,butasignofdigoxintreatment.Gynaecomastiaisarelativelycommonside-effectoflong-termtreatment,butnotoftoxicity.Bothhypercalcaemiaandhypokalaemiapredisposepatientstodevelopingdigoxintoxicitybutarenotinthemselvesaresultofthetoxicity.Blurringofthevisionandxanthopsia(yellowvision)canoccurintoxicity.

43.B–EnteroendocrinecellsCarcinoidtumoursareslow-growingneuroendocrinetumours.Two-thirdsofcarcinoidtumoursarefoundwithinthegastrointestinaltract,withthemidgut(duodenumtotransversecolon)beingthelocationoftheprimarytumourinupto75%ofgastrointestinalcases.Themostnotablesecretionisserotoninwhichmaycauseflushing,diarrhoea,wheezing,abdominalcrampingandperipheraloedema.

44.C–RightandleftgastricarteriesTheleftandrightgastricarteriessupplythelessercurvatureofthestomach.Theybranchfromthecoeliactrunkviathecommonhepaticarteries.Therightgastroepiploicarterysuppliestherightsideofthegreatercurvature.It isabranchofthegastroduodenalartery.Theleftgastroepiploicarterysuppliesthemiddlepartofthegreatercurvatureandisderivedfromthesplenicarteryandultimatelyfromthecoeliactrunk.Theshortgastricarteriessupplytheupperpartofthegreatercurvature.

45.A–APCTheAPC(adenomatouspolyposiscoli)tumoursuppressorgenehasbeenimplicatedincolorectalcancer.It is inherited in an autosomal dominant fashion and is located on the long (q) armof chromosome5.Inheritanceresults in thepresenceofbetween100and1000 tubularadenomaswhichcarpet thecolon,and less frequently the stomach and the small bowel (particularly the duodenum). The polyps usuallyappearinthesecondandthirddecadeoflifeandhavea100%malignantpotential.

46.B–Angiotensin-convertingenzymeinhibitorsACE(angiotensin-convertingenzyme)inhibitors,acommonlyusedclassofantihypertensive,cancauseadrycoughduetoincreasesinbradykininlevelssecondarytoinhibitionofdegradation.Bradykinincausesbloodvessels todilateand thus lowers thebloodpressure,butbradykinin-inducedbronchoconstrictionmaybethecauseofthecoughseeninsomepatients.

47. D – Presence of autoantibodies against the acetylcholine receptors at the neuromuscularjunctionMyasthenia gravis is an autoimmune condition characterized by the presence of autoantibodies againstacetylcholine (ACh) receptors at the neuromuscular junction (NMJ). The most common finding inmyastheniagravis is fatigability (i.e.musclesbecomegraduallyweakerwithactivity).Extraocularandfacialmusclesarecommonlyinvolved.Ptosis,diplopia,dysarthriaanddysphagiacanoccur,withdeathusuallyoccurringbecauseofrespiratorymusclefailure.Acetylcholinesteraseinhibitors(e.g.neostigmineandphysostigmine) canbeused in themanagementofmyastheniagravis.Theyworkbypreventing thebreakdownofAChinthesynapticcleft,increasingitsavailabilityfortransmissionattheNMJ.

48.C–DissociationofribosomesDissociation of ribosomes from the endoplasmic reticulum is characteristic of reversible cell injury.Irreversiblecell injuryleads tooneof twoendpoints,apoptosisornecrosis.Apoptosis isprogrammedcell death and is orderly in nature in comparison to necrosis,which is a traumatic formof cell deathsecondarytopathologicalstimuli,suchashypoxia,andisrandomanddiffuseinnature.

49.B–BRCA1TheBRCA1 (BreastCancer 1, early onset) tumour suppressor gene has been implicated in breast andovariancancer.Itisinheritedasanautosomaldominantgeneandislocatedonchromosome17q.CarriersofBRCA1havea lifetimeriskapproaching80%ofdevelopingbreastcanceranda40–60%increasedriskofdevelopingovariancancer.

50.A–AmitriptylineAmitriptylineisatricyclicantidepressantusedinthemanagementofchronicneuralgia.Side-effectsarepredominantlyantimuscarinicandcardiovascular.Anexampleofitsusewithregardtoneuropathicpainmanagement is for those who suffer with chronic functional abdominal pain. An alternative agent ofchoiceisgabapentin.

QuestionsPaper21.Whichofthefollowingistrueoflipopeptideantibiotics?

A. TheyareeffectiveagainstGram-negativebacteria.

B. TheyareeffectiveagainstGram-positivebacteria.

C. Theyareprimarilyexcretedbytheliver.

D. Theyareunabletobindprotein.

E. Theyareunabletobindtothecellmembrane.

2.Whichtypeofionchannelsdolocalanaestheticagentstarget?

A. Calciumchannels

B. Gamma-aminobutyricacidgatedchloridechannels

C. N-Methyl-d-aspartatecationchannels

D. Potassiumchannels

E. Sodiumchannels

3.Whichoneofthefollowingdrugsisaspecificinhibitorofbacterialdihydrofolatereductase?

A. Methotrexate

B. Nitisinone

C. Pemetrexed

D. Proguanil

E. Trimethoprim

4.Metastaticspreadofcancerviathebloodtothebonecanbecausedbywhichofthefollowingtumoursmostcommonly?

A. Brain

B. Lung

C. Neurofibroma

D. Oesophagus

E. Thyroid

5.Whichoneofthefollowingfunctionsdoosteoblastsperform?

A. Exchangeofnutrientsandwasteproducts

B. Productionofosteoid

C. Releaseofhydrogenions

D. Resorptionofbone

E. SecretionofcathepsinK

6.Quinolonesinhibitwhichpartofnucleicacidsynthesis?

A. Theyinhibitdihydrofolatereductase.

B. Theyinhibitdihydropteroatesynthetase.

C. TheyinhibitDNAgyrase.

D. TheyinhibitDNAsynthesisbyreducinganitrogroupandformingreactiveintermediates.

E. TheyinhibitRNApolymerase.

7.Whichofthefollowingstatementsregardingbloodsupplytothebrainisincorrect?

A. The internal carotid artery arises from the common carotid artery at the level of the suprasternalnotch.

B. Theophthalmicarteryisabranchoftheinternalcarotidartery.

C. Themiddlecerebralarteriessupplythelateralcortex.

D. Theposteriorcerebralarteriessupplythevisualcortex.

E. Thevertebralarteriesarebranchesofthesubclavianartery.

8.Whichvesselbeginsbeyondtheinguinalligament,andthenrunsintheadductorcanalbeforechangingitsnameasitpassesthroughthehiatusinadductormagnus?

A. Anteriortibialartery

B. Femoralartery

C. Poplitealartery

D. Posteriortibialartery

E. Profundusfemoris

9.Whichoneofthefollowingstatementsregardingskeletalmusclestructureiscorrect?

A. Actinfilamentsarethickerthanmyosinfilaments.

B. Sarcomeresaremadeupofmanymyofibrils.

C. Thesarcomereismadeupoflightanddarkbands;thelightpartsconsistofactinfilaments.

D. Thickfilamentsarecomposedoffourheavychainsofmyosinandaregulatorylightchain.

E. Zlinesanchorthethickmyosinfilaments.

10.Whichoneofthefollowingmusclesfacilitatesflexionofthehipjointandextensionattheknee?

A. Thebicepsfemoris

B. Therectusfemoris

C. Thesartorius

D. Thesemimembranosus

E. Thesemitendinosus

11.InwhichphaseofthecellcycleisDNAsynthesized?

A. G0phase

B. G1phase

C. G2phase

D. Sphase

E. Noneoftheabove

12.Whicharteryhasmultiplebranchespartlyorwhollysupplyinganumberofstructures including theface,tongueandthyroid?

A. Commoncarotid

B. Externalcarotid

C. Internalcarotid

D. Subclavianartery

E. Vertebralartery

13.Whichoneofthefollowingstatementsregardingthemusculatureofthelowerlimbiscorrect?

A. Contractionofthepsoasmajorresultsinextensionofthehip.

B. Thefemoralnervesuppliesthehamstringmuscles.

C. Theiliacus,theadductorlongusandtheinguinalligamentborderthefemoraltriangle.

D. Thesartoriusfacilitatessittingcross-legged.

E. Thesciaticnervesuppliesthequadricepsmuscles.

14. Muscles are composed of fast and slow muscle fibres. Which one of the following statementsregardingfastandslowfibresiscorrect?

A. Fastfibresareredincolourbecauseoflargeamountsofmyoglobin.

B. Fastfibresaresmallerforquickerreleaseofenergy.

C. Slowfibresareadaptedforprolongedmusclecontraction.

D. Slowfibreshavefewermitochondriathanfastfibres.

E. Slowfibresundergoonlyanaerobicmetabolism.

15.I-bandsconsistof:

A. Actin

B. Actinandmyosin

C. Myosin

D. Myosinandtropomyosin

E. Myosinandtroponin

16.Whichofthefollowingisresponsibleforproducingadenosinetriphosphate?

A. Golgiapparatus

B. Mitochondria

C. Nucleus

D. Ribosome

E. Roughendoplasmicreticulum

17.Acetylcholineisanagonistforwhichtargetreceptor?

A. 5HT2receptor

B. Betaadrenoceptor

C. Histaminereceptor

D. Nicotinicreceptor

E. μ-Receptor

18.Whichenzymeisthedrugtargetforstatins?

A. Cholineacetyltransferase

B. Cyclooxygenase

C. DOPAdecarboxylase

D. HMG-CoAreductase

E. Xanthineoxidase

19.Theprimaryfunctionofwhichofthefollowingistheprocessingandpackagingofmacromolecules?

A. Golgiapparatus

B. Mitochondria

C. Nucleus

D. Roughendoplasmicreticulum

E. Smoothendoplasmicreticulum

20.Inrespiratoryalkalosiswhichionisdecreasedinconcentration?

A. Calcium

B. Magnesium

C. Phosphate

D. Potassium

E. Sodium

21.Whichofthefollowingstatementsaboutmyelinatedaxonsistrue?

A. Actionpotentialconductionisslower

B. Axondiameterissmaller

C. Moreadenosinetriphosphateisneededforrepolarization

D. Moreenergyisneededfordepolarizationofthemembrane

E. Theyarecontainedonlywithinthecentralnervoussystem

22.Asarcomereisdefinedastheintervalbetweentwoadjacent:

A. A-bands

B. I-bands

C. Thickfilaments

D. Thinfilaments

E. Z-lines

23.Whichofthefollowingcanoccurwiththeuseofthetumournecrosisfactor-αinhibitorinfliximab?

A. Chronicautoimmunedisease

B. Diabetesinsipidus

C. Infertility

D. Reactivationoftuberculosis

E. Rhabdomyolysis

24.Whichoneofthefollowingdrugsdoesnotinhibitdihydrofolatereductase?

A. Allopurinol

B. Methotrexate

C. Pemetrexed

D. Proguanil

E. Trimethoprim

25.TheAPCtumoursuppressorgeneislocatedonwhichchromosome?

A. 17p

B. 5q

C. 7q

D. 13q

E. 17q

26. Which one of the following complement pathways would activate C3 via bacteriallipopolysaccharides?

A. Alternativepathway

B. Apoptosis

C. Classicalpathway

D. Lectinpathway

E. Tyrosinekinasepathway

27.Whichofthefollowingistruewithregardtolocalpotentials?

A. Summationoflocalpotentialsresultsininhibitionofanimpulse.

B. Thestrengthofelectricalpotentialislowestatthepointofinitiation.

C. Thestrengthofinitiatingstimulushasnoeffectonthemagnitudeofthepotential.

D. Thestrengthofthepotentialincreaseswithincreasingdistancefromthesiteofinitiation.

E. Theycantravelinbothdirectionsalonganaxon.

28.Whichofthefollowingdescribestherestingpotentialwithinaneuron?

A. −30mV

B. −55mV

C. −70mV

D. −90mV

E. +50mV

29.Whichofthefollowingistrueofβ-lactamantibiotics?

A. Thecellwallisunaffectedbytheiraction.

B. Theyareeffectiveagainstmycobacteria.

C. Theyareeffectiveagainstslowdividingbacteria.

D. Theyarenotthoughttobebactericidal.

E. Theyinhibittheenzymeswhichareinvolvedinthethirdstageofcellwallsynthesis.

30.Whichofthefollowingisanatypicalantipsychoticdrug?

A. Chlorpromazine

B. Flupentixol

C. Fluphenazine

D. Haloperidol

E. Olanzapine

31.Thep53tumoursuppressorgeneislocatedonwhichchromosome?

A. 17p

B. 5q

C. 7q

D. 13q

E. 17q

32.Whenanactionpotentialreachesasynapse,whatisdirectlyresponsiblefortriggeringtheexocytosisofneurosecretoryvesiclesintothesynapticcleft?

A. G-proteinsignaltransduction

B. IncreasedCa2+withinthepresynapticcytoplasm

C. IncreasedNa+withinthepresynapticcleft

D. Increasedproductionofacetylcholine

E. Theinfluenceofnoradrenaline

33.Whichoneofthefollowingisnotafunctionofmitochondria?

A. Calciumsignalling

B. Cellulardifferentiation

C. Cellularmigration

D. Productionofadenosinetriphosphate

E. Programmedcelldeath

34.Whichoneofthefollowingisnotanendproductofarachidonicacidmetabolism?

A. Laminin

B. Leukotriene

C. Prostacyclin

D. Prostaglandin

E. Thromboxane

35.Whichstructureisnotfoundinthebroadligament?

A. Ovarianligament

B. Ovary

C. Uterineartery

D. Uterinetube

E. Uterovaginalnerveplexus

36.Whichofthefollowingisnotabranchoftheinternalcarotidartery?

A. Anteriorcerebralartery

B. Anteriorchoroidalartery

C. Middlecerebralartery

D. Posteriorcerebralartery

E. Posteriorcommunicatingartery

37.Thevertebralarteriesuniteatthelowerborderoftheponstogiverisetowhichoneofthefollowing?

A. Anteriorspinalartery

B. Basilarartery

C. Cerebellarartery

D. Posteriorcerebralartery

E. Posteriorspinalartery

38.Whichofthefollowinggivesthecorrectsequenceofmitosis?

A. Prophase,anaphase,metaphase,telophase

B. Prophase,anaphase,telophase,metaphase

C. Prophase,metaphase,anaphase,telophase

D. Telophase,anaphase,prophase,metaphase

E. Telophase,prophase,anaphase,metaphase

39.Whichofthefollowingisthechiefinhibitoryneurotransmitterinthecentralnervoussystem?

A. Acetylcholine

B. Dopamine

C. Gamma-aminobutyricacid

D. Serotonin

E. Zinc

40.Whichoneofthefollowingisnotaneffectmediatedbyactivationofthecomplementcascade?

A. Activationandchemotaxisofleukocytes

B. Alterationofthehypothalamicthermostat

C. Celllysisofmicrobes

D. Increasedvascularpermeability

E. Phagocytosis

41.Whichoneofthefollowingisthemostcommonoutcomeofacuteinflammation?

A. Abscessformation

B. Organization

C. Progressiontochronicinflammation

D. Resolution

E. Suppuration

42.Whichenzymeisthedrugtargetforaspirin?

A. Acetylcholinesterase

B. Angiotensin-convertingenzyme

C. Cyclooxygenase

D. Monoamineoxidase

E. Thymidinekinase

43.Whichoneofthefollowingtargetreceptorsisintracellular?

A. Gamma-aminobutyricacidAreceptor

B. Insulinreceptor

C. Muscarinicacetylcholinereceptor

D. Nicotinicacetylcholinereceptor

E. Steroidreceptor

44.Whichstatementbestdescribestheovaries?

A. Theleftovarianveinjoinstheinferiorvenacava.

B. Theovarianarteryanastomoseswiththeinternaliliacartery.

C. Theyarelinedbyperitoneum.

D. Theyaresuppliedbytheovarianartery,abranchoftheabdominalaorta.

E. Theyliewithinthebroadligament.

45.Whichoneofthefollowingstatementsconcerningtheuterusisfalse?

A. Itisconnectedtothevaginaviathecervix.

B. Itisnormallyretroverted.

C. Itisprimarilysuppliedbytheuterineartery.

D. Itissupportedbytheurogenitalandpelvicdiaphragm.

E. Theanteriorsurfaceisrelatedtothebladder.

46.Whichmediumvesselvasculitisgivesrisetomicroaneurysmsandfibroidnecrosisofvesselswalls,isassociatedwithhepatitisBantigenaemiaandprimarilyaffectsmiddle-agedmen?

A. Classicalpolyarteritisnodosum

B. Giantcellarteritis

C. Kawasakidisease

D. Takayasuarteritis

E. Wegenergranulomatosis

47.Thesynthesisofprostaglandinsandthromboxanesisstimulatedbywhichenzyme?

A. Cyclooxygenase

B. HMG-CoAreductase

C. Lipoxygenase

D. Myeloperoxidase

E. Xanthineoxidase

48.DeficiencyincomplementC3wouldmakeapatientmoresusceptibletowhichoneofthefollowing?

A. Bacterialinfection

B. Parasiticinfection

C. Priondisease

D. Systemiclupuserythematosus

E. Virusinfection

49.Whattermismostcommonlyappliedtothevascularaneurysmsthatmaybeseeninsyphilisinfection?

A. Berry

B. Connectivetissueabnormality

C. Cysticmedialdegeneration

D. False

E. Mycotic

50.Whichofthefollowingconditionsisassociatedwithgranulomatousinflammationoftheaortaanditsmajorbranches?

A. Classicalpolyarteritisnodosum

B. Giantcellarteritis

C. Kawasakidisease

D. Takayasuarteritis

E. Wegenergranulomatosis

AnswersPaper21.B–TheyareeffectiveagainstGram-positivebacteriaDaptomycin is an example of a novel lipopeptide antibiotic. The activity of these agents is limited toGram-positive bacteria. Lipopeptide antibiotics bind to the cell membrane, creating disruptions thatallowionleakage.Thisresultsinrapiddepolarizationwithaconsequentlossofthemembranepotentialwhichinhibitsprotein,RNAandDNAsynthesis.

2.E–SodiumchannelsLocal anaesthetic agents, such as lidocaine, block voltage-gated sodium channels to prevent thedepolarizationrequiredforactionpotentialgeneration.Asaresult,neurotransmissionisblocked.

3.E–TrimethoprimTetrahydrofolicacidisanessentialprecursorforthesynthesisofDNA,anddihydrofolatereductaseisanenzyme in themetabolic pathway that produces tetrahydrofolic acid. Inhibiting dihydrofolate reductasestops the synthesis of this folic acid, thus depleting the precursors available for DNA synthesis.Trimethoprimspecificallyactsonbacterialdihydrofolatereductase,thusdepletingbacteriaoffolicacid.Asbacteriaareunabletousefolicacidfromthehost,theyareunabletosynthesizeDNAandreplicate.Assuch,trimethoprimisabacteriostaticantimicrobial.

4.E–ThyroidTumours that spread to the bony skeleton via the bloodstreamusually arise from the bronchus, breast,thyroid,kidneyorprostate.Bonymetastasesareproblematicastheycanresultinsevereintractablepain,bonyfractures,hypercalcaemiaandcordcompression. It isdifficult forcancercells tosurviveoutsidetheirregionoforigin,soinordertometastasizetheymustfindalocationwithsimilarcharacteristics.Forexample, breast tumours which gathered calcium ions from breast milk can metastasize to bones andgathercalciumfromthebone.

5.B–ProductionofosteoidOsteoblastsarethecellsresponsibleforboneformation.Theydothisbyproducingosteoid(mainlytypeIcollagen). They arise from progenitor cells within the bonemarrow and periosteum.As they becomematurecellstheyexpressdifferentproteins,suchasosteopontinandosteocalcin,whichareinvolvedinvariousphasesofboneregulation.Osteoblastsbecomeosteocyteswhentheybecomepartof thematrixinto which they secrete. They are able to degrade bone though a rapid mechanism called osteocyticosteolysis.Osteoclastsareresponsiblefortheremovalofbonetissue.Thisoccursthroughtheresorptionoforganicbone.TheyalsosecretecathepsinKwhich is involved in the lysisofcollagen.Through theactionofcarbonicanhydrase,osteoclastsreleasehydrogenions.Thisallowsthedissolutionofthebonematrix.

6.C–TheyinhibitDNAgyraseQuinolones inhibit DNA gyrase (also known as DNA topoisomerase II, an enzyme required in DNAunwinding). Trimethoprim and methotrexate inhibit dihydrofolate reductase. Sulphonamides inhibit

dihydropteroate synthetase. Rifampicin inhibits RNA polymerase. 5-Nitroimidazoles (such asmetronidazole)inhibitDNAsynthesisbyreducinganitrogroupandformingreactiveintermediates.

7. A – The internal carotid artery arises from the common carotid artery at the level of thesuprasternalnotchThe internalcarotidartery isabranchof thecommoncarotidartery,butarisesat the levelof the thirdcervicalvertebra.ThesuprasternalnotchisattheT2/3vertebrallevel.TheinternalcarotidarteriescanbedividedintosevensegmentsaccordingtotheBouthillierclassification.Thesevenpartscomprisethefollowing (from proximal to distal): cervical segment; petrous segment; lacerum segment; cavernoussegment;clinoidsegment;ophthalmic(supraclinoid)segment;andthecommunicating(terminal)segment.

8.B–FemoralarteryThefemoralartery is thecontinuationof theexternal iliacarterybelowthe inguinal ligament. Itpassesthroughthefemoralcanal,accompaniedbythefemoralvein,femoralnerveandlymphatics.Theanatomyofthisareaisofeverydayclinicalrelevance,particularlywithreferencetoacupuncture,arteriopuncture,central lineinsertionandherniaformation.Ausefulmnemonicfortheorderofthestructureswithinthefemoralcanal is ‘NAVY’ (nerve,artery,vein,Y-fronts– running lateral tomedial).The femoralarteryinitially runs anteriorly before passing under sartorius to the gap in adductormagnus and entering thepoplitealfossa–thispassagebeneathsartoriusandthroughadductormagnusistheadductor(orHunter’s)canal.

9.C–Thesarcomereismadeupoflightanddarkbands;thelightpartsconsistingofactinfilamentsSkeletal muscle is striated and made up of myofibrils, which are divided into sarcomeres. EachsarcomereisdividedfromthenextbytheZline,composedofactinins,whichanchorsthethinfilaments.(‘Z’isfromtheGermanZwischenscheibe=thediscinbetween.)Thinfilamentsaremadeofactin,whilethethickcomprisemainlymyosin.Thickandthinfilamentsarearrangedsothattheyinterdigitatewithoneanother.Lightbandsaremadeupof thin filaments,while thedarkbandscompriseoverlappingmyosinandactin.MusclecontractionisbroughtaboutbythinfilamentsmovingoverthethickfilamentsviaATP-dependentcross-bridgeformation.

10.B–TherectusfemorisThe rectus femoris muscle is innervated by the femoral nerve and allows flexion at the hip joint. Itsinsertion into the quadriceps tendon also facilitates knee extension. Rectus femoris is one of the fourcomponentsofthequadricepsfemoris, theotherthreebeingvastuslateralis,vastusmedialisandvastusintermedius. The semimembranosus, the semitendinosus and the biceps femorismake up the hamstringmuscles,whichfacilitatekneeflexionandhipextension.

11.D–SphaseDNAreplicationoccursduringtheS(synthesis)phaseofthecellcycle.Duringthisphase,thereisalsoinitiationofproteinsynthesisandreplicationoforganelles.

12.B–ExternalcarotidThecommoncarotidbifurcatesintotheinternalandexternalcarotidarteriesabovethelevelofthethyroidcartilage.Theexternalcarotidhasmultiplebranchesprovidingvascularsupplytothethroat,mouthandexternalstructuresofthehead.

13.D–Thesartoriusfacilitatessittingcross-legged

The sartoriusmuscle, etymologically the ‘tailor’smuscle’, enables hip flexion and lateral rotation, aswellasflexionat theknee. It is innervatedby thefemoralnerve,attaches to theanteriorsuperior iliacspine and runs inferomedially. The femoral triangle contains the femoral nerve, artery and vein, inadditiontothedeepinguinallymphnodes.Itisborderedbytheinguinalligamentanteriorly,theadductorlongusmediallyandthesartoriuslaterally.Thequadricepsaresuppliedbythefemoralnerveandcausekneeextension,whilekneeflexionandhipextensionarecontrolledbythehamstrings,whicharesuppliedbythesciaticnerve.

14.C–SlowfibresareadaptedforprolongedmusclecontractionSlowfibresarealsoknownasredmusclebecauseoftheirhighlevelsofmyoglobin.Theyhavealargenumberofmitochondriaforhighlevelsofoxidativemetabolism.Fastfibres,orwhitemuscle,arelargerandhave large amounts of glycolytic enzymes for the rapid releaseof energy.Fast fibres areused forshort-acting,powerfulmusclecontractions.

15.A–ActinThickmyofilaments lie between the thinmyofilaments.Thepartial interdigitationbetween the thin andthickmyofilamentsgivestheappearanceofthelightanddarkbandswhichgivestriatedskeletalmuscleitsname(Latinstriae=furrows).LightI-bandsareportionsofactinwhichdonotoverlapwithmyosin.Dark A-bands, on the other hand, represent the filaments of actin which overlap with the myosinfilaments.The ‘I’ and ‘A’ stand for isotropic andanisotropic – termswhich relate to their propertiesunderpolarizedmicroscopy.

16.B–MitochondriaMitochondria are responsible for the production of adenosine triphosphate (ATP), which is a cell’ssource of energy. The nucleus containsmost of a cell’s geneticmaterial and is amembrane-enclosedorganelle.Aribosomeisresponsiblefortheproductionofproteinsfromaminoacids.Theyaredividedintotwosubunits.ThesmallerofthetwobindstomessengerRNAandthelargerbindstotransferRNA.Rough endoplasmic reticulum is so called because of the presence of ribosomes bound to its surface.Theyarenotastablepartofthestructureastheyareconstantlybeingreleasedfromthemembrane.

17.D–NicotinicreceptorAcetylcholine is an agonist for nicotinic receptors. Nicotinic receptors are thus part of the class ofcholinergic receptors, with muscarinic receptors being the other predominant member. Nicotinicreceptors are commonly found at neuromuscular junctions, and activation by acetylcholine leads to aninfluxofsodiumandaresultantactionpotential.

18.D–HMG-CoAreductaseHMG-CoA(3-hydroxy-3-methylglutaryl-coenzymeA)reductaseisanenzymeinvolvedinthebiosynthesisof cholesterol. Statins are competitive inhibitors of this enzyme, thus the drug reduces cholesterolsynthesis and is widely used in treating hypercholesterolaemia. Statins not only lower cholesterol bydirectlyreducingsynthesisthroughcompetitiveinhibitionoftheenzyme,butalsobyincreasinguptakeoflow-density lipoproteins (LDLs).This is because the reduced synthesis of cholesterolmeans the bodyupregulatesLDLreceptors,whichhasthebeneficialeffectofincreasingLDLuptakefromtheblood.

19.A–GolgiapparatusThe Golgi apparatus processes and packages macromolecules, such as proteins, for their subsequentsecretion or usewithin the cell.Mitochondria are responsible for the production ofATPwhich is thecell’s source of energy. The nucleus contains most of a cell’s genetic material and is a membrane-

enclosedorganelle.A ribosome is responsible for theproductionofproteins fromaminoacids.Roughendoplasmicreticulumissocalledbecauseofthepresenceofribosomesboundtoitssurface.

20.A–CalciumAsthepHrisesthroughtheeliminationofcarbondioxide,thereisaconcomitantdecreaseintheionizedcalciumconcentration.Inalkalosis,theproteininthebloodbecomesionizedintoanions.Thiscausesfreecalciumpresentinbloodtobindstronglytoprotein,leadingtotetanyifsevere.

21.B–AxondiameterissmallerMyelinated neurons are found both within the central nervous system (CNS) and peripheral nervoussystem (PNS). They allow faster action potential conduction and consume lower levels of energy andATP. This is because only a small portion of membrane needs to undergo depolarization andrepolarization, as the action potential can jump between areas of myelin insulation (‘saltatoryconduction’).Becauseactionpotentialconductionisfasterinmyelinatedneurons,theirdiametercanbesmallerwithoutcompromisingspeed.Thisallowsgreaterspaceefficiency.

22.E–Z-linesSkeletalmusclefibresconsistofseveralsmallersubunitscalledmyofibrils.Thesemyofibrilsareaseriesofparallelsubunitsthatcontainthecontractileproteinsoftheskeletalmusclefibre.Whenviewedclosely,myofibrilshaveastriatedappearancewithlightanddarkbands.ThelightbandsarecalledI-bandsandconsistofthinmyofilamentscomposedpredominantlyofactin,withtroponinandtropomyosin.ThedarkbandsarecalledA-bandsandaremadeupofthickmyofilamentswhichconsistmainlyofmyosin.TheZ-line is a line which dissects each I-band. The interval between two adjacent Z-lines is called asarcomere,andthisisthebasiccontractileunitofskeletalmuscle.

23.D–ReactivationoftuberculosisInfliximab is a cytokine modulator that inhibits tumour necrosis factor-α (TNF-α) and is used in themanagement of rheumatoid arthritis and Crohn disease. Because it dampens the immune response, itpredisposestoinfection.Ithasbeenshowntoreactivatelatenttuberculosissopatientsmustbeassessedfor thepresenceof infectionbeforecommencing infliximab.Reactivationof latentTB ishighest in thefirst twelve months of treatment. All patients commenced on anti-TNF therapies need to be closelymonitoredforTB.Thisneedstocontinuefor6monthsafterdiscontinuinginfliximabtreatmentduetotheprolongedeliminationphaseofinfliximab.

24.A–AllopurinolDihydrofolate reductase is an enzyme used in the synthetic pathway of purines, required for DNAsynthesis.Trimethoprimactsonbacterialdihydrofolatereductase,methotrexateandpemetrexedworkonhumandihydrofolatereductase,whileproguanilworksonparasiticdihydrofolatereductase.Asaresultofthis specificity, each has different clinical indications, e.g. trimethoprim is used to treat bacterialinfections,whereasproguanilisusedtotreatparasiticinfectionslikemalaria.Allopurinolisaxanthineoxidaseinhibitorandisusedtotreatgout.

25.B–5qThetumoursuppressorgenenamedAPC(adenomatouspolyposiscoli)islocatedonchromosome5q.Itisinheritedinanautosomaldominantfashionandresultsintheformationofhundredstothousandsoftubularadenomaswithinthecolon.Theseadenomatouspolypsare100%premalignantandneedtobesurgicallyexcisedtopreventprogressiontocancer.

26.A–AlternativepathwayComplementC3iscleavedtoformC3aandC3bwithinplasma.ThealternativecomplementpathwayistriggeredbyC3bbinding.C3bcanattachtocellsurfaces,butisinhibitedbysialicacidonmammaliancell surfaces. Some microbes and virus cell membranes lack sialic acid. To this end, C3b can bindlipopolysaccharideonGram-negativebacteriaand independently initiate thecomplementcascademorequicklythanviaantibodyactivation.

27.E–TheycantravelinbothdirectionsalonganaxonBeforeelectricalsignalsareformed,therehastobeachangeincellchargefromtherestingmembranepotential. Local potentials are generated by chemical,mechanical or electrical inputs received by theneuroncausingsmalldepolarizations.Theelectricalcurrentsproducedcantravelineitherdirectionalonganaxon.Thestrengthofthepotentialgenerateddependsuponthestrengthoftheinput,andasaresulttheyaremaximallystrongatthepointofgeneration.Thestrengthofthepotentialquicklydiminishesthefurtherthe signal travels from its original source. Summation of local potentials, rather than inhibiting animpulse,isawaytoincreasetheirstrength.

28.C––70mVTherestingpotentialofaneuronmembraneis–70mV,closetotheequilibriumpotentialforpotassiumions (–90 mV, dictated by the Nernst equation). In order for an action potential to be generated, thethresholdlevelof–55mVwithinaneuronhastobereached.Myocyteshavearestingpotentialof–90mV.Theequilibriumpotential forsodiumis+70mV.As themembranedepolarizesandmoreNa+ ionsentertheneuron,itsmembranepotentialwillbecomeclosertothislevel.

29.C–TheyareeffectiveagainstslowdividingbacteriaBacterial cell walls are made from peptidoglycans. These peptidoglycans are essential for cell wallstructural integrity, and theconsequent inhibitionof synthesisbyβ-lactamantibiotics leads tobacterialdeath.

30.E–OlanzapineAtypicalantipsychoticsaresocalledbecausetheyworkdifferentlyfromtypicalantipsychotics,butmostaffectserotoninanddopaminereceptors.

31.A–17pThep53 (protein53) tumoursuppressorgene,which is implicated inmore than50%ofallcancers, islocatedonchromosome17(17p13.1).Thep53geneisalsoknownastheguardianofthegenomebecauseithassuchan important role incell regulation.Thep53gene is responsible foractivatingDNArepairproteins–itcanarrestcellgrowthbystoppingthecellcycleattheG1/Sphase,allowingdamagedDNAtoberepaired.Thep53geneisalsoresponsibleforactivatingapoptosisinresponsetoseverelydamagedDNA.

32.B–IncreasedCa2+withinthepresynapticcytoplasmDepolarizationofthepresynapticmembraneviaaninfluxofNa+resultsintheopeningofvoltage-gatedCa2+channels.IncreasedCa2+withinthecytoplasmencouragesexocytosis.

33.C–CellularmigrationMitochondria have a central role in the production of ATP. They are also vitally important in theregulation of the membrane potential, apoptosis, calcium signalling, cellular proliferation and steroid

synthesis.Theyarenot,however,involvedincellularmigration.

34.A–LamininLaminins are glycoproteins essential for the structure of the basal lamina (part of the basementmembrane). They are coded for, and produced by, various cells involved within the inflammatoryresponse.

35.B–OvaryTheovariesarenotpartof thebroad ligament,butareattached to thebroad ligamentviaa foldof theperitoneumknownasthemesovarium.

36.D–PosteriorcerebralarteryTheposteriorcerebralarteryisaterminalbranchofthebasilarartery.Alltheotherarteriesarebranchesoftheinternalcarotidartery.

37.B–BasilararteryThebasilararteryisformedthroughtheunificationofthetwovertebralarteriesatthebaseofthelowerborderof thepons. Itgives rise toseveralbranches including theanterior inferiorcerebellar, superiorcerebellar,labyrinthineandtheposteriorcerebralarteries.

38.C–Prophase,metaphase,anaphase,telophaseThecorrectsequenceofmitosisisprophase,metaphase,anaphaseandtelophase.Thekeyfeaturesofeachareasfollows:

Prophase:chromatincondensationandmitoticspindleformation

Metaphase:chromosomealignmentattheequatorofthespindle

Anaphase:sisterchromatidsareseparatedandmigratetooppositepoles

Telophase:sisterchromatidsarriveatthespindlesanddecondense

39.C–Gamma-aminobutyricacidGamma-aminobutyric acid (GABA) is the required neurotransmitter at the majority of fast inhibitorysynapses of the central nervous system. Serotonin, dopamine and acetylcholine are the excitatoryneurotransmittersinthenervoussystem.Zincisnotaneurotransmitter.

40.B–AlterationofthehypothalamicthermostatAlterationofthehypothalamicthermostatisproducedbyseveralcytokinesincludinginterleukin2(IL-2)andtumournecrosisfactoralpha(TNF-α)butisnotaconsequenceofcomplementactivation.

41.D–ResolutionResolution occurs followingminimal tissue damage and results in complete tissue regeneration to itsoriginal function and structure. This is themost common outcome. Suppuration and abscess formationoccurwhenaninfectiveagentpersistswithinatissue.Organizationdescribestheprocessbywhichthecomponents of a tissue are replaced with fibrous or scar tissue. Progression to chronic inflammationoccursifthecausativeagentisnotabletoberemoved.

42.C–Cyclooxygenase

Aspirinisaninhibitorofcyclooxygenase(COX).AspirinirreversiblyacetylatespartoftheactivesiteofCOX-1andchangestheactivityofCOX-2,renderingtheenzymeincapableoffurthersuccessfulenzyme–substrate reactions.COXisanenzyme involved in theproductionofprostaglandinsand thromboxanes.Aspirinisthusabletoreducetheproductionofthese,resultinginananti-inflammatory,antipyretic,anti-inflammatoryandantiplateletactivity.

43.E–SteroidreceptorAlltheoptionslisted,apartfromsteroidreceptors,aremembranereceptors.Thesteroidreceptorsareallintracellularnuclearreceptorsandinfluencegenetranscription.IntracellularsteroidreceptorscompriseaDNAbindingdomain,variabledomain,hingeregionandhormonebindingdomain.Thehingeregion isknown to control receptormovement,whereas theDNAbinding domain controls gene activation. Thedomaincompriseszincandcysteineresidues.

44.D–Theyaresuppliedbytheovarianartery,abranchoftheabdominalaortaTheovariesarenot linedbyperitoneum,and thusanoocyte is released into theperitonealcavity.Theanterior surface of the ovary is attached to the broad ligament via a fold of the peritoneum (themesovarium).The leftovarianveindrains into the left renalvein,while therightovarianveindirectlyjoins the inferior vena cava (a similar distribution pattern to the testicular veins). The ovarian arteryanastomoseswiththeuterineartery.

45.B–ItisnormallyretrovertedTheuterusisnormallyantevertedandanteflexed.Itisonlyretrovertedinaround20%ofwomen.Alltheothergivenstatementsaretrue.

46.A–ClassicalpolyarteritisnodosumPolyarteritisnodosaisamediumvesselvasculitis.Itismostcommoninadultmalesandisoftenseeninassociation with hepatitis B infection. Immune complex deposition causes a type III hypersensitivityreaction. There can be systemic involvement, but a classic exam presentation is a middle-aged manpresentingwithabdominalpainandrenalfailure.

47.A–CyclooxygenaseCyclooxygenase(COX)istheenzymerequiredtosynthesiseprostaglandinsandthromboxanes.Xanthineoxidasecatalysestheoxidationofxanthinetouricacid.Allopurinol,usedinthepreventionofgout,isaxanthineoxidase inhibitor.HMG-CoA reductase convertsHMG-CoA tomevalonic acid, and this is animportant step in cholesterol formation. Statins are HMG-CoA reductase inhibitors.Myeloperoxidase(MPO)iscontainedinneutrophilsandproduceshypochlorousacidfromhydrogenperoxidetoenabletheoxidativekillingofmicrobes.Lipoxygenaseenablestheproductionofleukotrienesfromarachidonicacid.

48.A–BacterialinfectionReductionincomplementC3resultsinareducedabilitytoeliminatemicrobesviaopsonizationandthemembrane attack complex. This is a large component of the body’s immune response to bacterialinvasion.EffectivedeficiencyofC3canalsooccurwithadeficiencyoffactorHorfactorI(inhibitorsofcomplementactivation)duetotheinappropriateactivationofC3viathealternativepathway.DeficiencyofC1predisposesanindividualtoSLE,becausethereislessopsonizationofimmunecomplexesviatheclassicalpathway.Thisreducesthenumberofsolubleimmunecomplexes,encouragingtheirprecipitationwithintissues.

49.E–Mycotic

Initially,mycotic was a term reserved for fungal aneurysms but it is now commonly applied to allaneurysmswithinfectiveaetiology.Laterstagesofsyphilisinfectioncanleadtolossofthevasavasorumwithintheaortaandotherlargearteries,leadingtoaneurysmsofthesevessels.

50.D–TakayasuarteritisTakayasu arteritis, often known as pulseless disease or aortic arch syndrome, is classified as a largevessel vasculitis. It chiefly affects females, the classic presentation being in youngAsianwomen.Theaetiology isunknownand thedisease is rare. Itcausesgranulomatous inflammationof theaortaand itsmajorbranches,givingrisetodifficultyinpalpationofsomeoftheperipheralpulses.

QuestionsPaper31.Whichofthefollowingdrugsisachimericmonoclonalantibodydirectedagainstplatelets?

A. Abciximab

B. Aspirin

C. Dipyridamole

D. Indomethacin

E. Prasugrel

2.Fromwhichareaoftheoralcavitydoestheglossopharyngealnerveconveythesensationoftaste?

A. Theanteriortwo-thirdsofthetongue

B. Thebackoftheoralcavity

C. Thelateralsidesofthetongue

D. Theposteriorone-thirdofthetongue

E. Theposteriortwo-thirdsofthetongue

3.Whichofthefollowingmovementsisfacilitatedbyteresmajor?

A. Abductoroftheshoulderjoint

B. Extensionattheelbowjoint

C. Flexoroftheshoulderjoint

D. Lateralrotationoftheshoulder

E. Medialrotationoftheshoulder

4.Whichpulseisfoundmidwaybetweentheanteriorsuperioriliacspineandthepubicsymphysis?

A. Brachial

B. Carotid

C. Femoral

D. Popliteal

E. Radial

5.Whichofthefollowingistheareabetweentwoadjoiningcellswhichformsanimpermeablebarriertofluid?

A. Desmosomes

B. Gapjunction

C. Zonulaadherens

D. Zonulaoccludens

E. Noneoftheabove

6.Whichoneofthefollowingcollagentypesispresentinhyalinecartilage?

A. TypeIcollagen

B. TypeIIcollagen

C. TypeIIIcollagen

D. TypeIVcollagen

E. TypeVcollagen

7.Whichoneofthefollowingisanon-immunefunctionofthelymphaticsystem?

A. Electrolytebalance

B. Fattransport

C. Glucosehomeostasis

D. Proteinabsorption

E. Toxindegradation

8.Towhichoneof the followingdrugsused in the treatmentofheart failuredopeopleoftendeveloptolerance?

A. Carvedilol

B. Enalapril

C. Furosemide

D. Isosorbidemononitrate

E. Metoprolol

9.Whichofthefollowingelectrolyteabnormalitiescanincreasethelikelihoodofdigoxintoxicity?

A. Hypercalcaemia

B. Hyperkalaemia

C. Hypermagnesemia

D. Hypocalcaemia

E. Hyponatraemia

10.Whichisthemostcommontypeoflaryngealcarcinoma?

A. Adenocarcinoma

B. Basalcellcarcinoma

C. Squamouscellcarcinoma

D. Verrucouscarcinoma

E. Noneoftheabove

11.Whichoneofthefollowingispresentwithinakeratinocyte?

A. Basallamina

B. Costamere

C. Desmosome

D. Hemidesmosome

E. Noneoftheabove

12.Whichoneofthefollowingisanimmigrantcellofconnectivetissue?

A. Adipocyte

B. Fibroblast

C. Macrophage

D. Mastcell

E. Monocyte

13.Atwhichvertebralleveldoesthetracheacommence?

A. C5

B. C6

C. C7

D. C8

E. T1

14.Tardivedyskinesiaisleastassociatedwithwhichofthefollowingdrugs?

A. Clozapine

B. Haloperidol

C. Olanzapine

D. Quetiapine

E. Risperidone

15. In a patient with depression at a high risk of taking an overdose, which one of the followingantidepressantclasseswouldbethesafesttoprescribe?

A. Benzodiazepines

B. Monoamineoxidaseinhibitors

C. Selectiveserotoninreuptakeinhibitors

D. Serotonin–noradrenalinereuptakeinhibitors

E. Tricyclicantidepressants

16.AfemalepatienthasbeenstartedonanewmedicationbyherGP.Shereturns3weekslaterstatingthatsinceshehasstartedonthisdrugshehasmusclepainandwishestostoptakingthedrug.Whichdrughasshemostlikelybeenstartedon?

A. Digoxin

B. Metoprolol

C. Ramipril

D. Simvastatin

E. Spironolactone

17.Amalepatientiswellcontrolledonwarfarinforhisatrialfibrillation.WhichofthefollowingdrugsisknowntoincreasingtheINRinpatientstakingwarfarin?

A. Allopurinol

B. Carbamazepine

C. Phenobarbital

D. Phenytoin

E. Rifampicin

18.Whichofthefollowingisnotabranchvesselassociateddirectlyorindirectlywiththeinternaliliacartery?

A. Inferiorrectalartery

B. Inferiorvesicalartery

C. Internalpudendalartery

D. Superiorvesicalartery

E. Testicularartery

19.Whichof the following are found at the base of the intestinal crypts and contain large acidophilicgranules?

A. Enterocytes

B. Enteroendocrinecells

C. Gobletcells

D. Panethcells

E. Stemcells

20.Whichoneofthefollowingcontainscadherinswhichencirclethecell?

A. Desmosomes

B. Gapjunction

C. Tightjunctions

D. Zonulaadherens

E. Noneoftheabove

21.Whichofthefollowingstatementsregardingheartvalvesiscorrect?

A. Theaorticandmitralvalvesbothhavethreeleaflets.

B. Theaorticandpulmonaryvalvesaretricuspid.

C. Theaortic,mitralandtricuspidvalvesallhavethreeleaflets.

D. Theaorticvalveistheonlycardiacvalvetohavethreeleaflets.

E. Thepulmonaryandmitralvalvesarebicuspid.

22.Whichofthefollowingmusclesisnotsuppliedbythemediannerve?

A. Theabductorpollicisbrevis

B. Theadductorpollicisbrevis

C. Theflexorpollicisbrevis

D. Theopponenspollicis

E. Thepronatorteres

23. Use of which one of the following drugs is an absolute contraindication in bilateral renal arterystenosis?

A. Amlodipine

B. Bendroflumethiazide

C. Bisoprolol

D. Carvedilol

E. Ramipril

24.Whichoneofthefollowingstatementsregardinganalgesiaiscorrect?

A. Fentanylisasyntheticopioidcommonlyusedinanaesthesia.

B. Morphineisafirst-lineagentinthetreatmentofheadaches.

C. Paracetamoliseffectiveintreatingseverepain.

D. Pepticulcerationisacommonside-effectoffentanyluse.

E. Respiratorydepressionisacommonconsequenceofnon-steroidalanti-inflammatorydruguse.

25.Horner’ssyndromeresultsinatriadofsignsduetolossofthesympatheticinnervation.Theseare:

A. Pupillaryconstriction,droopingofeyelidandlossofsweatingaroundaffectedeye

B. Pupillaryconstriction,retractionofeyelidandlossofsweatingaroundbotheyes

C. Pupillaryrelaxation,droopingofeyelidandlossofsweatingaroundaffectedeye

D. Pupillaryrelaxation,retractionofeyelidandlossofsweatingaroundbotheyes

E. Noneoftheabove

26.Fromwhichareaofthetonguedoesthefacialnerveconveythesensationoftaste?

A. Theanteriortwo-thirdsofthetongue

B. Thecentreofthetongue

C. Thelateralsidesofthetongue

D. Theposteriorone-thirdofthetongue

E. Theposteriortwo-thirdsofthetongue

27.Whichoneofthefollowingnervessuppliesthegluteusmaximus?

A. Thefemoralnerve

B. Theinferiorglutealnerve

C. Theobturatornerve

D. Thesciaticnerve

E. Thesuperiorglutealnerve

28.Whichofthefollowingbestdescribesthelocationoftheatrioventricularnode?

A. Positionedbetween the atria andventricles in theposteroinferior regionof the interatrial septum,neartheopeningofthecoronarysinus

B. Positionedbetweentheatriaandventriclesintheventricularseptum

C. Positionedintheinferiorwalloftherightatriumlateraltothetricuspidvalve

D. Positionedintheleftventricularapex

E. Positionedonthewalloftherightatriumneartheentranceofthesuperiorvenacava

29.WhichofthefollowingisnotaconstituentoftheαβT-cellreceptor?

A. Constantregion

B. Cytoplasmictail

C. Disulphidebond

D. Kappasegment

E. Variableregion

30.Whichofthefollowingstatementsregardingthespleenisincorrect?

A. Thespleenisasecondarylymphoidorgan.

B. Thespleenisnotaretroperitonealorgan.

C. Thespleenissuppliedbyafferentlymphatics.

D. Thespleenissuppliedbythesplenicartery.

E. Thespleenliesintheleftupperquadrantoftheabdomen.

31.Epitheliumisdefinedbytheexpressionofwhichadhesionmolecule?

A. E-cadherin

B. E-selectin

C. N-cadherin

D. P-cadherin

E. T-cadherin

32.Whatshapeisthecartilageinthetrachea?

A. Continuousrings

B. C-shaped

C. Δ-(delta)shaped

D. Ω-(omega)shaped

E. Noneoftheabove

33.Sexualdysfunctionisanadverseeffectmostassociatedwithwhichofthefollowingdrugs?

A. Lithium

B. Monoamineoxidaseinhibitors

C. Noradrenalineandspecificserotonergicantidepressants

D. Serotonin–noradrenalinereuptakeinhibitors

E. Selectiveserotoninreuptakeinhibitors

34.Theaxonsoftheganglioncellsentertheopticnerveviawhichofthefollowing?

A. Ciliarybody

B. Foveacentralis

C. Maculalutea

D. Opticbulb

E. Opticpapilla

35.Howmanytypesofconearetherewithrespecttospectralsensitivity?

A. 2

B. 3

C. 4

D. 5

E. 6

36.Whichofthefollowinggroupsofmusclesmakeuptherotatorcuff?

A. Latissimusdorsi,levatorscapulae,teresminor,subscapularis

B. Serratusanterior,teresminor,trapezius,subscapularis

C. Supraspinatus,subclavius,subscapularis,teresminor

D. Teresmajor,teresminor,deltoid,latissimusdorsi

E. Teresminor,infraspinatus,supraspinatus,subscapularis

37.Whichoneofthefollowingisnotafunctionofantibodies?

A. Activatingcomplement

B. Neutralizingtoxins

C. PresentingantigentoT-lymphocytes

D. Preventingbacterialadhesiontotissuesurfaces

E. Promotingphagocytosisthroughopsonization

38. The region of an antigen to which an immunoglobulin molecule or cell surface receptor binds isknownasthe:

A. Allotype

B. Epitope

C. Heavychain

D. Lightchain

E. Opsonin

39.InwhichpartofthesmallintestineareMeckeldiverticulausuallyfound?

A. Duodenum

B. Ileum

C. Jejunum

D. Alloftheabove

E. Noneoftheabove

40.Howmanylayersmakeuptheretina?

A. 4

B. 5

C. 6

D. 7

E. 8

41.Whichofthefollowingantianginaldrugsisapotassiumchannelactivator?

A. Bisoprolol

B. Diltiazem

C. Glyceryltrinitrate

D. Isosorbidemononitrate

E. Nicorandil

42.Whichoneofthefollowingcelltypeshasnoaxonalprocess?

A. Amacrinecells

B. Cones

C. Ganglioncells

D. Horizontalcells

E. Rods

43.Whichofthefollowingformsananastomosisbetweenthesuperiorandinferiormesentericarteries?

A. Ileocolicartery

B. Leftcolicartery

C. MarginalarteryofDrummond

D. Middlecolicartery

E. Rightcolicartery

44.WhichoneofthefollowingisnotpartofatypicalIgGantibodymolecule?

A. Disulphidebridges

B. Fab

C. Fbc

D. Fc

E. Hypervariableregions

45.Whichofthefollowingbestdescribesthelocationofthesinoatrialnode?

A. Haswidevariabilitywithregardtoitspositionfrompersontoperson

B. Positionedintheapicalaspectoftherightventricle

C. Positionedintheleftatrialappendage

D. Positionedintherightatrialseptalwall

E. Positionedonthewalloftherightatriumneartheentranceofthesuperiorvenacava

46.PeptideYYisprincipallysecretedbycellsinwhichpartofthesmallintestine?

A. Duodenum

B. Jejunum

C. Proximalileum

D. Terminalileum

E. Noneoftheabove

47.Thetracheaislinedwithwhichtypeofepithelium?

A. Ciliatedpseudostratifiedcolumnar

B. Ciliatedstratifiedcolumnar

C. Simplecolumnar

D. Simplesquamous

E. Stratifiedsquamous

48.Whichofthefollowingnerverootsinnervatesthekneejerk(patellartendon)reflex?

A. L1,L2

B. L2,L3

C. L3,L4

D. L4,L5

E. L5,S1

49.Whichtypeofmuscleistrachealis?

A. Cardiac

B. Myotilin

C. Skeletal

D. Smooth

E. Noneoftheabove

50.Whichofthefollowingdrugsusedinacutemyocardialinfarctionshouldbeadjustedforpatientswithrenalimpairment?

A. Aspirin

B. Clexane

C. Clopidogrel

D. Losartan

E. Ramipril

AnswersPaper31.A–AbciximabAbciximabisachimericmonoclonalantibodywhichirreversiblybindsGpIIb/IIIareceptorsinplatelets.This prevents the final commonpathwayof platelet aggregation. It is licensed for use in patientswithunstable angina and non-ST elevation myocardial infarction who are undergoing primary coronaryintervention.Theterm‘chimeric’refers to thefact that theseantibodiesarederivedfromDNAsourcesfrommorethanoneanimalspecies(oftenmouseandhuman).

2.D–Theposteriorone-thirdofthetongueTheglossopharyngeal(IX)nerveoriginatesfromthemedulla.Itdetectstastesensationfromtheposteriorone-thirdof the tongueandalsoreceivessensory informationfromthe tonsils,pharynxandmiddleear.Commonpathologiesincludetrauma,brainstemlesionsandnecktumours.Itistestedviathegagreflex.

3.E–MedialrotationoftheshoulderTeresmajorisamuscleoftheposteriorshoulderwhichisinsertedontheanterioraspectofthehumerus(medialsideofthebicipitalgroove).Itallowsmedial(orinternal)rotationattheshoulderjoint.Itisalsoashoulderadductorandisinnervatedbythelowersubscapularnerve.

4.C–FemoralThefemoralartery ispalpatedat thegroinbypressing thefemoralarteryagainst the inguinal ligament.Thefemoralarterytravelsthroughthegroininthefemoralcanal,accompaniedbythefemoralveinandfemoralnerve.

5.D–ZonulaoccludensTight junctions (zonulaoccludens) are theareas inwhichcells are soclosely joined together and theyform virtually impermeable barriers. The major proteins which produce the tight junctions includeclaudinsandoccludins.

6.B–TypeIIcollagenTypeIIcollagenispresentinhyalinecartilage.Itmakesupto50%ofallproteinsincartilage.Itformsafibrillarnetworkwhichsupportstheproteoglycanaggregatetoprovidetensilestrength.

7.B–FattransportLactealsarelymphaticswithinthesmallintestinethatpenetrateeachvillustoenablefatabsorbedinthesmallintestinetobecarriedawayintothelymphaticsystem.

8.D–IsosorbidemononitratePatientscanrapidlydeveloptolerancetonitrates,suchasisosorbidemononitrate.Theprobabilityofthishappeningcanbereducedbyensuringthatpatientshavean8-hourperiodwithin24hourswheretheyarefreeofnitratetreatment.Nitratesactbydecreasingthepreloadbycausingperipheraldilation.Adecreaseinthepreloadimprovesthecardiacoutput.

9.A–HypercalcaemiaDigoxinisacardiacglycosideextractedfromthefoxgloveplant.ItexertsitsactionsbyinhibitionoftheNa+/K+ATPasepumpanddecreasesconductionthroughtheatrioventricularnode.Digoxintoxicitycanbeprecipitatedbyhypokalaemia,hypomagnesemiaandhypercalcaemia.

10.C–SquamouscellcarcinomaSquamouscellcarcinomaisthemostcommontypeoflaryngealtumour,asthemajorityofthelaryngealepithelium is squamous. Verrucous carcinoma is a rare variant of squamous cell carcinoma which islinkedtotheuseofsnuff.

11.D–HemidesmosomeDesmosomespromote cell-to-cell adhesion tohelp resist shearing forces.Acostamere is a structural–functional component of striated muscle cells which join the force-generating sarcomeres to thesarcolemma. Hemidesmosomes are very small structures present on the inner basal surface ofkeratinocytes and act like desmosomes by forming spot junctions. The basal lamina is a layer ofextracellularmatrixuponwhichtheepitheliumsits.

12.E–MonocyteAmonocyte is an immigrant cellwhichwillmove to connective tissuewhen required to increase themacrophage population. A fibroblast synthesizes extracellular matrix and collagen. A macrophage(histiocyte)isfixedinconnectivetissue.Amastcellisalsoaresidentcell.

13.A–C5The trachea starts at the larynxwhich is levelwith theC5 vertebra. It continues until it bifurcates tobecometheprimarybronchiattheT4/5level.

14.A–ClozapineTardive dyskinesia manifests itself after long-term or high-dose antipsychotic use. While atypicalantipsychoticsarethoughttobeassociatedwithadecreasedriskof tardivedyskinesia, thisassociationhasonlybeendemonstratedwithclozapine.

15.C–SelectiveserotoninreuptakeinhibitorsSelective serotonin reuptake inhibitors (SSRIs) are the safest antidepressant class when taken inoverdose.ThiswasreportedinastudybyIsbisteretal.whodemonstratedthatsuchagentsaresaferinanoverdose despite serotonin syndrome being common. It was also concluded that citalopram was anexceptiontotherule,asitwasassociatedwithQTcprolongation.

16.D–SimvastatinStatinscancausemyositisandanelevatedcreatinekinase(CK)level.Patientsinitiatedontreatmentwithstatinsshouldbewarnedoftheside-effectsandadvisedtodiscontinueuseiftheydevelopmusclepainsor aching. Itmay be possible to try using a different statin; however, youmay find that the patient isintolerantofallstatins,andanalternativeagentmayneedtobeconsidered.MonitortheCKlevelsiftheyareelevated,alongwiththerenalfunction.

17.A–AllopurinolEnzyme inducers and inhibitors are common exam question topics. The liver enzyme inducers candecreasetheeffectsofanumberofdrugs,includingwarfarin,andtheenzymeinhibitorscanincreasetheeffectsofdrugs.Inhibitionoftheenzymesslowsdownthemetabolismofdrugsandthereforepotentiates

their effects. The enzyme inducers can be remembered by the mnemonic PC BRAS (Phenytoin,Carbamazepine,Barbiturates,Rifampicin,Alcohol [chronicexcess],Sulphonylureas)and the inhibitorsby AODEVICCES (Allopurinol, Omeprazole, Disulfiram, Erythromycin, Valproate, Isoniazid,Ciprofloxacin,Cimetidine,acuteEthanolintoxication,Sulphonamides).

18.E–TesticulararteryThetesticulararteriesarebranchesoftheaorta.Embryologically,thetesticlesdescendintothepelvisandretain their superiorbloodsupply rather thangaining their supply fromthe internal iliacartery like themajorityofthepelviccontents.

19.D–PanethcellsPanethcellsarefoundthroughouttheintestinaltract,wheretheysitatthebottomofintestinalcrypts.Theycontainzincandlysozyme.Theyarethoughttocontributetothehostdefenceandregulationofintestinalflora.Enterocytesarethemaincellsoftheintestine,gobletcellssecretemucousandstemcellsareabletobecomeanytypeofintestinalcell.

20.D–ZonulaadherensThe zonula adherens (intermediate junctions) are the protein complexes which occur at cell-to-celljunctions.They appear as bandswhich encircle the cell.Cadherins are transmembraneproteinswhichbindcellstogetherandaredependentuponcalciumions.

21.B–TheaorticandpulmonaryvalvesaretricuspidTheeasiestwaytorememberthisisthatthemitralvalveistheonlyonethatisbicuspid.Alloftheothercardiacvalves(aortic,pulmonaryandtricuspid)havethreevalveleaflets.Thetricuspidvalveusuallyhasthreeleaflets,althoughsometimesitmayhavetwoorfourleaflets,andthenumbermaychangeduringitslife.Themost common formof congenital heart disease is a bicuspid aortic valve, and this occurs inapproximately1%ofthepopulation.Patientsoftenpresentwithaorticvalvestenosisattheageof40–60yearsasaresultofcongenitalbicuspidvalves.

22.B–TheadductorpollicisbrevisThemuscles of the hand that are supplied by themedian nerve can be remembered by themnemonic‘LOAF’:

Lateraltwolumbricals

Opponenspollicis

Abductorpollicisbrevis

Flexorpollicisbrevis

The remainder are supplied by the ulnar nerve. Pronator teres is supplied by the median nerve andfacilitatespronationoftheforearm.

23.E–RamiprilPatients with bilateral renal artery stenosis become dependent on the renin–angiotensin–aldosteronesysteminordertomaintainrenalperfusion.Ifeitheranangiotensin-convertingenzyme(ACE)inhibitororangiotensin-receptor blocker (ARB) is employed in the treatment of their hypertension, you will

essentiallycompleteachemicalnephrectomy.ACEinhibitorsandARBscanbeusedtogether,understrictguidance, for the treatment of heart failure and hypertension. Some large trials have shown particularbenefitincombinationtreatmentforpatientswithheartfailure.

24.A–FentanylisasyntheticopioidcommonlyusedinanaesthesiaParacetamol is used to treatmild tomoderate pain and is the first-line analgesic agent prescribed forsimple tension headaches. Respiratory depression is an important side-effect of opioid use. Pepticulceration is associatedwith non-steroidal anti-inflammatory drugs (NSAIDs), such as diclofenac andibuprofen.

25.A–Pupillaryconstriction,droopingofeyelidandlossofsweatingaroundtheeyeHorner’ssyndromedescribesatriadofsignswhichoccurunilaterally:miosis(constrictedpupil);partialptosis (drooping of the eyelid); and loss of facial sweating (anhydrosis). Enophthalmos (posteriordisplacementoftheeye)mayalsobepresent.Horner’ssyndromeiscausedbyanipsilateralinterruptionofthesympatheticnervesupplytotheeye.

26.A–Theanteriortwo-thirdsofthetongueThe facialnervearises from thebrainstembetween themedulla and thepons. Its functions include thecontrol of muscle of facial expression and taste sensation to the anterior two-thirds of the tongue.Pathology that affects the facial nerve include Bell’s palsy, cerebello-pontine angle tumours, parotidtumoursandherpeszosterinfection.

27.B–TheinferiorglutealnerveThegluteusmaximusisamuscleofthebuttockregionthatactstoextendandrotatethethigh.Itissuppliedbytheinferiorglutealnerve,derivedfromsegmentsL5–S2.Theobturatornervesuppliestheadductorsofthe thigh, including the adductor longus, adductor magnus, adductor brevis and gracilis. The superiorgluteal nerve innervates the abductors (gluteusmedius, gluteusminimus and tensor fasciae latae). Thesciatic nerve descends medial to psoas major and ultimately travels under gluteus maximus into theposterior compartment to supply the hamstrings.Finally, the femoral nerve supplies the quadriceps, aswellasrectusfemorisandpectineus.

28.A–Positionedbetweentheatriaandventriclesintheposteroinferiorregionoftheinteratrialseptum,neartheopeningofthecoronarysinusThe atrioventricular node (AVN) conducts electrical impulses received from the sinoatrial node. TheAVNcreates an important delay in conduction (usually 0.12 seconds), allowing atrial systole to occurpriortotheventricularsystole.TheAVNcontrolstherateatwhichventricularcontractionoccursandhasanintrinsicfiringrateof40–60beatsperminute.Theintrinsicratebecomesimportantinthecontextofdeciphering heart blocks. The classic example is complete heart block, where there is completeatrioventriculardissociation.Hereweseeaventricularrate(QRScomplex)ofbetween40and60beatsperminute,andanatrialrate(P-waves)between60and100beatsperminute.TheP-wavesaresaidto‘marchthrough’theQRScomplexesontheECG.

29.D–KappasegmentThemostcommonformofT-cellreceptoristheαβT-cellreceptor.Itisatransmembranereceptormadeup of two main subunits connected by disulphide bonds. Both subunits have cytoplasmic tails, atransmembranalregionandextracellularhinge,constantandvariableregions.

30.C–Thespleenissuppliedbyafferentlymphatics

Thespleenfiltersbloodandtrapsblood-bornepathogensbuthasnoroleinfilteringlymph.Itthereforehas no lymphatic supply or drainage. It is however a key secondary lymphoid organ. The spleen issuspended within its mesentery between the lienorenal ligament and gastrolienal ligament. The otherstatementsinthequestionaretrue.

31.A–E-cadherinEpithelialcadherin(E-cadherin)isacalcium-dependentcell-to-celladhesionmolecule.Lossoffunctionisthoughttocontributetotheproliferationofcancer.E-cadherindownregulationdecreasesthestrengthofcellular adhesion within a tissue, allowing cells to cross the basement membrane and invade thesurroundingtissue.

32.B–C-shapedThetracheaiscomprisedof15–20C-shapedcartilaginousringswhichareabletoreinforcethelateralandanteriorsidesoftheairway.Theposteriorsurfacebetweenthefreeendsofthecartilageisreinforcedbythetrachealismuscle.

33.E–SelectiveserotoninreuptakeinhibitorsTheeffectofSSRIsonsexualfunctionisstillpoorlyunderstood.Ithasbeenhypothesizedthattheeffectsofserotonergicdrugsonsexualfunctionmayrelatetodrugdose,serotoninreceptorsubtypesaffectedandtherelativeeffectonserotonergicversusotherreceptors.

34.E–OpticpapillaTheganglioncells,whicharefoundintheganglionlayeroftheretina,entertheopticnerveviatheopticpapilla.Thiscorrespondstoabreakinthevisualfieldcalledtheblindspotandisdevoidofanylight-sensitiverodsorcones.

35.B–3Conesarespecializedphotosensitivereceptorsfoundintheretinaandarecapableofphototransduction.Theyfunctionoptimallyinbrightlightandaremainlyfoundinthecentralareaoftheretina.Conesallowcolourperceptionandtherearethereforethreetypes:onesensitivetored,onesensitivetogreenandonesensitivetoblue.

36.E–Teresminor,infraspinatus,supraspinatus,subscapularisTherotatorcuffprotectstheshallowglenohumeraljoint,stabilizingtheheadofthehumerusintheglenoidfossa. The supraspinatus abducts the humerus, while the other three muscles facilitate rotation. Theinfraspinatus and teres minor laterally rotate and adduct, while the subscapularis is responsible formedial rotation.The rotator cuffmuscles can be remembered by themnemonic ‘SITS’: Supraspinatus,Infraspinatus,TeresminorandSubscapularis.

37.C–PresentingantigentoT-lymphocytesIgA in seromucous secretions has a particular role in preventing adhesion of bacteria to mucosalepithelia. Antibodies play a role in neutralizing bacterial toxins such as cholera and tetanus toxins.ComplementbindingtotheFcportionoftheantibodyactivatescomplementthroughtheclassicalpathway.

38.B–EpitopeThe epitope is also known as antigenic determinant.The variable region of theFab (fragment antigen-binding)portionofanantibodyistheregionwhichhasspecificitytoindividualepitopes.

39.B–IleumIn the fetus the ileum is connected to the umbilicus by the vitelline duct. If this duct fails to close, aMeckeldiverticulumwillpersist.Meckeldiverticulaarepresentinapproximately2%ofthepopulation,located2feetfromtheileocaecalvalve,andareusually2inchesinlength.Therearetwotypesofectopictissue thatmaybe foundwithin these structures: gastric andpancreatic.Patients generallypresent at 2yearsofage (e.g.withpainless rectalbleedingor intussusception)andmalesare twiceas likely tobeaffected.

40.E–8The retina isa light-sensitive tissue that lines the innerpartof theeye. It iscomposedofeight layers:pigment;photoreceptor;outernuclear;outerplexiform;innernuclear;innerplexiform;ganglioncell;andnervefibre.Theretinaalsocontainstheopticdiscwheretheganglioncellaxonsleavetheeyetoformtheopticnerve–thiscorrespondstotheblindspotasitisdevoidofphotoreceptors.

41.E–NicorandilNicorandil is a potassiumchannel activator and results in arterial vasodilation. It alsohas nitrate-likeproperties and promotes venous relaxation. Nicorandil can cause similar side-effects to nitrates,includingheadache, flushing, hypotension anddizziness. Patients shouldbe startedon small doses andtitrateduptosymptomaticrelief.

42.A–AmacrinecellsAmacrine cells have no axons. They are octopus-like cells with dendrites emerging from one side.Amacrinecellsareinterneuronsthatregulatethebipolarcellsandtheganglioncellsintheretina.Theyareresponsibleforcomplexprocessingoftheretinalimage,specificallyadjustingimagebrightnessand,byintegratingsequentialactivationofneurons,detectingmotion.

43.C–MarginalarteryofDrummondThemarginalarteryofDrummondanastomosesthesuperiorandinferiormesentericarteries.Itrunsintheperitoneum and its absence should be considered an anatomic variant. The splenic flexure isapproximately at the mid-point of the marginal artery and is the area most susceptible to watershedischaemia.

44.C–FbcIgG antibodies are made up of two Fab (fragment antigen-binding) regions and an Fc (fragmentcrystallizable)regionconnectedbyahingeregion.Fabregionseachhaveahypervariableregionattheirdistalendtowhichepitopesbind.DisulphidebridgesarefoundinthehingeregionandbetweentheheavyandlightchaincomponentsoftheFabregion.

45.E–PositionedonthewalloftherightatriumneartheentranceofthesuperiorvenacavaThesinoatrialnode(SAN)isaclusterofspecializedcellsoftenreferred toas theprimarypacemaker.Thesecellsspontaneouslygenerateelectricalimpulsesandconductanelectricalchargeresultinginatrialcontraction. There is subsequent electrical conduction to the atrioventricular node. The SAN has anintrinsicpacemaker rateof60–100beatsperminute. Interruptions in theconductionof theseelectricalimpulsescanresultinavarietyofarrhythmias.

46.D–Terminalileum

PeptideYYissecretedbytheL-cellsofthegastrointestinalmucosa.L-cellsareprincipallyfoundintheileumandrectum,althoughtheyarepresent throughout thegastrointestinal tract.PeptideYYcirculationincreasespostprandiallyandreducesintestinalmotility,gallbladdercontractionandpancreaticexocrinesecretion.Italsoreducesappetite(i.e. isananorectic)andis thereforethoughttobeafactor inenergyhomeostasis.

47.A–CiliatedpseudostratifiedcolumnarThe trachea is lined with ciliated pseudostratified columnar epithelium. The term ‘pseudostratified’meansthatwhilethereisonlyasinglelayerofcells,thenucleiofthesecellsarepositionedsimilarlytostratified epithelia. The cilia act as one unit and beat rhythmically to removemucous and irritants topreventtheirdescentfurtherintotherespiratorytract.

48.C–L3,L4Striking the patella tendon with a tendon hammer causes passive stretching of the muscle which isdetectedbymusclespindles.AfferentsignalsfromthemusclespindlestravelviaIanervefibres.Theα-motorneuronthencarriesefferentsignalstofacilitatecontractionofrectusfemoris,resultinginextensionoftheknee.Tendonreflexesformanintegralpartofthenervoussystemexamination.Exaggeratedreflexesoccur inuppermotorneuron lesionsand inhyperthyroidism,whilediminished reflexesoccur in lowermotorneuronlesions.

49.D–SmoothTrachealisisasmoothmusclewhichattachestothecartilaginousringsofthetrachea.Thefunctionofthismuscleistoallowconstrictionofthetrachea.Thisconstrictionallowsforahighervelocityofairflowinthetracheawhencoughing.

50.B–ClexanePatients with ischaemic heart disease commonly have renovascular disease. Low molecular weightheparin(suchasclexane[enoxaparin]),atenololanddigoxinmayaccumulateinsevererenalfailureduetopoorexcretion.PatientswithaGFR<10mL/min shouldhave thedoseof enoxaparinhalved.Someeven recommend that the dose be halved for those patients with a GFR <30 mL/min. Angiotensin-converting enzyme (ACE) inhibitors and angiotensin-receptor blockers should be used with extremecautioninpatientswithrenalfailure.

QuestionsPaper41.TheRB1tumoursuppressorgeneislocatedonwhichchromosome?

A. 17p

B. 5q

C. 7q

D. 13q

E. 17q

2.Atwhatvertebrallevelisthelowerendoftheconusmedullarisfoundalongthespinalcord?

A. C1–C2

B. L1–L2

C. S1–S2

D. T1–T2

E. T11–T12

3.Whichof thefollowing ischaracteristicofasurgical thirdnerve(CNIII)palsy incomparison toamedicalcause?

A. Disruptionofthepupillaryreflex

B. Involvementofthefacialnerve

C. Sparedpupillaryinvolvement

D. Theeyefacingdown

E. Unilateralptosis

4.Whatisthecorrectorderofamonosynapticreflexarc?

A. Afferentneuron,sensoryreceptor,integrationcentre,efferentneuron,muscle

B. Muscle,efferentneuron,afferentneuron,integrationcentre,sensoryreceptor

C. Muscle,sensoryreceptor,afferentneuron,integrationcentre,efferentneuron

D. Sensoryreceptor,afferentneuron,integrationcentre,efferentneuron,muscle

E. Sensoryreceptor,efferentneuron,integrationcentre,afferentneuron,muscle

5.Whichofthefollowingarepolymersoftubulin?

A. Actinfilaments

B. Intermediatefilaments

C. Microtubules

D. Alloftheabove

E. Noneoftheabove

6.Whichoneofthefollowingisanon-organizedtypeofgut-associatedlymphoidtissue?

A. Cryptopatches

B. Intraepitheliallymphocytes

C. Isolatedlymphoidfollicles

D. Mesentericlymphnodes

E. Peyerpatches

7.Towhatisthefilumterminaleanchored?

A. Thebaseoftheskull

B. Theclavicle

C. Thecoccyx

D. TheL1vertebrae

E. Theribs

8.Succinyl-CoAisformedbytheactionofwhichenzymeinthecitricacidcycle?

A. Fumaratehydratase

B. Isocitratedehydrogenase

C. Malatedehydrogenase

D. Oxoglutaratedehydrogenase

E. Succinatedehydrogenase

9.Whereisthecaudaequinafound?

A. Atthecervicalsectionofthevertebralcanal

B. AttheL1–L2sectionofthevertebralcanal

C. AttheT11–T12levelofthevertebralcanal

D. Inthecerebellum

E. Inthecerebralcortex

10.Thedenticulateligamentsare:

A. Partofthearachnoidspace

B. Partoftheduramater

C. Partoftheduralspace

D. Partofthepiamater

E. Partofthesubarachnoidspace

11.Whichofthefollowingistrueofglycopeptideantibiotics?

A. TheyareactiveagainstGram-negativeorganisms.

B. Theyareanexampleofadrugwhichhasalowtoxicity.

C. Theyarenevernephrotoxic.

D. Theyinhibitpeptidoglycansynthesis.

E. Theypenetrateintothecerebrospinalfluid.

12.Whereisthefasciculusgracilisfound?

A. Lateralwhitecolumns

B. Posteriorgreycolumns

C. Posteriorlateralsulcus

D. Posteriormediansulcus

E. Posteriorwhitecolumns

13.WhichlayerofthegastrointestinaltractcontainstheMeissner’splexus?

A. Mucosa

B. Muscularisexterna

C. Muscularismucosa

D. Serosa

E. Submucosa

14.Inwhichlayerofthegastrointestinaltractisthegut-associatedlymphoidtissueprimarilyfound?

A. Mucosa

B. Muscularisexterna

C. Muscularismucosa

D. Serosa

E. Submucosa

15.Whichtypeoftissuelinestheoesophagus?

A. Cuboidalepithelium

B. Simplecolumnarepithelium

C. Simplesquamousepithelium

D. Stratifiedsquamousepithelium

E. Transitionalepithelium

16.Thepylorusofthestomachisatwhichvertebrallevel?

A. L1

B. L2

C. T10

D. T11

E. T12

17.Duringtheconversionofisocitratetooxoglutarateinthecitricacidcycle,whatisformed?

A. NADHandCO2

B. NADHandH2O

C. NADPHandCO2

D. NADPHandCO2andH+

E. NADPHandH2O

18.Whichofthefollowingistrueofaminoglycosideantibiotics?

A. Theyarealwaystakenorally.

B. TheyareineffectiveagainstGram-negativebacteria.

C. Theyarenotototoxic.

D. Theyinhibitthetranslocationofthepeptidyl-tRNA.

E. Theyworkbybindingtothebacterial60Sribosomalsubunit.

19.Whichfour-carboncompoundreactswithacetyl-CoAinthecitricacidcycle?

A. Citrate

B. Oxaloacetate

C. Oxoglutarate

D. Pyruvate

E. Succinate

20.Whichoneofthefollowingstatementsaboutthepulmonarypleuraisincorrect?

A. PleuralreflectionsoneachsidemeetattheangleofLouis.

B. Thediaphragmaticpleuraisinnervatedbythevagusnerve.

C. Theparietalpleuraisinnervatedbytheintercostalnerves.

D. Thepleuralapexextends2.5cmabovetheclavicle.

E. Visceralpleuraonlyhasautonomicinnervation.

21.Whichistheoutermostcoveringofthespinalcord?

A. Arachnoidmater

B. Duramater

C. Piamater

D. Subarachnoidspace

E. Subduralspace

22. Cardiac arrhythmias are not a common side-effect of which of the following electrolyteabnormalities?

A. Hyperkalaemia

B. Hypermagnesaemia

C. Hypokalaemia

D. Hypomagnesaemia

E. Hyponatraemia

23.Acetyl-CoAisformedbytheconversionofwhat?

A. Acetylcholine

B. Acetyline-CoA

C. Glucose

D. Glycerol-3-phosphate

E. Pyruvate

24.Apatient is found tobehypokalaemicpostoperatively.Whichof the followingelectrolytes, if alsolow,willneedtobecorrectedwithintheplasmabeforethehypokalaemiawillcorrectlyresolve?

A. Bicarbonate

B. Calcium

C. Chloride

D. Magnesium

E. Sodium

25.Whichoneofthefollowingcancausehypernatraemia?

A. ACEinhibitortherapyinapatientwithrenalarterystenosis

B. Excessuseof5%dextroseforIVfluidreplacement

C. Highserummagnesium

D. Multipleburns

E. SyndromeofinappropriateADHsecretion

26.Followingthetransfusionofsixunitsofblood,apatient’scorrectedcalciumlevelwasnotedtobelow.Whyhasthisoccurred?

A. Citratewithinbloodproductsbindsplasmacalcium.

B. Citratewithinbloodproductsresultsinincreasedcalciumexcretion.

C. Excesspotassiumionsreleasedfromtransfusedcellsaretransportedintocellsalongwithcalciumions.

D. Hypocalcaemia is likely to have resulted from deranged nutritional intake while critically ill inhospital.

E. Transfusedredbloodcellscontainalbuminwhichbindsplasmacalcium.

27.A53-year-oldwomanbeingtreatedforbipolardisorderdevelopshypothyroidism.Whatisthemostlikelyoffendingdrug?

A. Amitriptyline

B. Citalopram

C. Fluoxetine

D. Haloperidol

E. Lithium

28.Anelderlymalepatientpresentstotheemergencydepartmentinatrialfibrillationandisfoundtobehypokalaemic. If the patientwas taking all of the belowmedications,whichwould you choose todiscontinuefirst?

A. Aspirin75mgod

B. Bendroflumethiazide2.5mgod

C. Cyclizine50mgtds

D. Omeprazole20mgod

E. Spironolactone100mgod

29.Whichoneofthefollowingpartsofthemitochondriacontainsadenosinetriphosphatesynthase?

A. Crista

B. Innermembrane

C. Matrix

D. Outermembrane

E. Ribosome

30.Whichofthefollowinglesionscausesinternuclearophthalmoplegia?

A. Alaterallongitudinalfasciculuslesion

B. Amediallongitudinalfasciculuslesion

C. Atrochlearnervelesion

D. Anabducensnervelesion

E. Anoculomotornervelesion

31.Whichoneofthefollowingincreasesthesurfaceareaforchemicalreactionswithinthemitochondria?

A. Cristae

B. Innermembrane

C. Matrix

D. Outermembrane

E. Ribosome

32.Whichoneofthefollowingisfoundincentrosomes?

A. Alphatubulin

B. Betatubulin

C. Gammatubulin

D. Alloftheabove

E. Noneoftheabove

33.Whichofthefollowingmedicationsisanabsolutecontraindicationinpregnancy?

A. Carbimazole

B. Iodine

C. Levothyroxine

D. Propylthiouracil

E. Radioiodine

34.Lidretractionisaclinicalmanifestationofhyperthyroidism.Whatcausesthisandwhichdrugmaybeusedtotreatit?

A. Parasympatheticoveractivityofsmoothmuscle;carbimazole

B. Parasympatheticoveractivityofsmoothmuscle;levothyroxine

C. Parasympatheticover-innervationofskeletalmuscle;levothyroxine

D. Sympatheticoveractivityofsmoothmuscle;carbimazole

E. Sympatheticover-innervationofskeletalmuscle;carbimazole

35.Patients shouldbeadvised to seek immediatemedicaladvice if theyexperiencesymptomssuchassorethroat,fever,mouthulcersandbleedingwhentakingwhichdrug?

A. Carbimazole

B. Iodine

C. Levothyroxine

D. Liothyronine

E. Propranolol

36.WhichofthefollowingclassesofantibioticismosteffectiveagainstGram-negativesepsis?

A. Aminoglycosides

B. Macrolides

C. Oxazolidinones

D. Penicillins

E. Tetracyclines

37.Combinationdrugco-trimoxazoleis:

A. Effectiveat1/10ofthedoseofwhatwouldbeneededifgivenseparately

B. Effectiveat1/1000ofthedoseofwhatwouldbeneededifgivenseparately

C. Knowntohavenoeffectonfolatesynthesis

D. Knowntopotentiatetheactionoftinzaparin

E. Lesseffectivethanwhengivenseparately

38.Clindamycinisatypeofwhichantibioticgroup?

A. Fluoroquinolones

B. Lincosamides

C. Macrolides

D. Penicillins

E. Tetracyclines

39.Whichofthefollowingisthemostcommoncauseofanacuteupperrespiratoryinfection?

A. Bacteria

B. Fungi

C. Parasite

D. Virus

E. Noneoftheabove

40.Whichofthefollowingisthemostcommoncauseofanupperrespiratorytractinfection?

A. Adenovirus

B. Influenzavirus

C. Parainfluenzavirus

D. Respiratorysyncytialvirus

E. Rhinovirus

41.Whichofthefollowingisnotacauseofperipheralcyanosis?

A. Deepveinthrombosis

B. Hypothermia

C. Hypovolaemia

D. Polycythaemiarubravera

E. Raynaudphenomenon

42.Whatkindofhearingdeficitismostfrequentlyproducedbyanacousticneuroma?

A. Asymmetricalhearingloss

B. Balanceproblems

C. Completehearingloss

D. Progressivetinnitus

E. Vertigo

43.Whichof thefollowingischaracteristicofaparalyticsquintbut isnota featureofanon-paralyticsquint?

A. Itisalwaysconvergent

B. Itisalwaysdivergent

C. Itisanacquiredcondition

D. Itisassociatedwithdiplopia

E. Itispresentfrombirth

44.TheRasproto-oncogeneismutatedinwhatpercentageofhumancancers?

A. 10%

B. 25%

C. 40%

D. 50%

E. 75%

45.Whichoneofthefollowingisnotacauseofhyperkalaemia?

A. Addisondisease

B. Connsyndrome

C. Massivebloodtransfusion

D. Metabolicacidosis

E. Rhabdomyolysis

46.TheRasgenecodesforwhichprotein?

A. ATPaseproteins

B. Epidermalgrowthfactorreceptor

C. GTPaseproteins

D. Platelet-derivedgrowthfactor

E. Vascularendothelialgrowthfactor

47.Whichofthefollowingconditionscausesadegenerationofretinalganglioncells?

A. Glaucoma

B. Leberhereditaryopticneuropathy

C. Meningioma

D. Parkinson’sdisease

E. Retinitis

48.Whichofthefollowingcausesasensorineuralhearingimpairmentasopposedtoconductivedeficit?

A. Foreignbody

B. LongQTsyndrome

C. Ménièredisease

D. Pendredsyndrome

E. Wax

49.MutationintheRasgeneproducesaproteinthat:

A. Codesfortheepidermalgrowthfactorreceptor

B. Codesfortheplatelet-derivedgrowthfactor

C. Codesforthevascularendothelialgrowthfactor

D. Isalwaysactive

E. Isnotactive

50.Whatmoleculeisfumarateconvertedtointhecitricacidcycle?

A. Malate

B. Oxaloacetate

C. Oxoglutarate

D. Pyruvate

E. Succinate

AnswersPaper41.D–13qTheRB1 (retinoblastoma) gene is implicated in causing the rare eye cancer retinoblastoma. TheRB1gene can be found on chromosome 13q. In hereditary retinoblastoma, sufferers are born with onedefectiveRB1 allele.Amutation then occurs on the remaining good allele, resulting in two defectivecopiesof thegene.This results in the formationof retinoblastoma.Theseare rareeye tumoursusuallyaffectingchildrenunder5yearsofage.

2.B–L1–L2Theconusmedullarisisattheterminalendofthespinalcord,atthevertebrallevelL1/2.Theupperendoftheconusmedullarisisnotusuallywelldefined.

3.A–DisruptionofthepupillaryreflexThirdnervepalsieswithoutpupildilationarecharacteristicofamedicalcause,suchasdiabetesorgiantcellarthritis.On theotherhand,earlydilationof thepupilassociatedwith thepalsy issuggestiveofacompressiveor‘surgical’causeastheparasympatheticfibres,whichareinvolvedinthepapillaryreflex,runontheouteraspectofthenerve.

4.D–Sensoryreceptor,afferentneuron,integrationcentre,efferentneuron,muscleThe receptor at the end of a sensory neuron reacts to a stimulus. The afferent neuron conducts nerveimpulsesalonganafferentpathwaytowardsthecentralnervoussystem.Theintegrationcentreconsistsofoneormoresynapsesinthecentralnervoussystem.Theefferentneuronconductsanerveimpulsealonganefferentpathwayfromtheintegrationcentretoaneffector.Wheretheeffectorisaskeletalmuscle,itrespondstotheefferentimpulsesbycontracting.

5.C–MicrotubulesMicrotubulesarepolymersoftubulinandareusuallymadefrom13tubulinmonomers.Elongationoccursatthepositiveendofthepolymer.Actinisthemonomersubunitofmicrofilamentsandthinfilaments,andintermediatefilamentsproduceadimerwhichisformedthroughthecoilingoftwomonomers.

6.B–IntraepitheliallymphocytesNon-organizedgut-associated lymphoid tissue (GALT) includes intraepithelial lymphocytes and laminaproprialymphocytes.OrganizedGALTsarecryptopatches,Peyerpatches,isolatedlymphoidfolliclesandmesentericlymphnodes.GALTgenerateslymphoidcellsandantibodies.Itisatypeofmucosa-associatedlymphoidtissue(MALT).

7.C–ThecoccyxThefilumterminale(terminalthread)isthefibrousextensionofthepiamaterfromtheapexoftheconusmedullaris. It consists of two parts. The upper part reaches the lower border of the second sacralvertebrae.Itissurroundedbythenerveswhichformthecaudaequina.Thelowerpartiscloselyadherenttotheduramaterandisattachedtotheposterioraspectofthefirstsegmentofthecoccyx.Itisalsoknownasthecoccygealligament.

8.D–OxoglutaratedehydrogenaseOxoglutarateisafive-carboncompound.Itismetabolizedbytheenzymeoxoglutaratedehydrogenasetoformsuccinyl-CoA.Duringtheconversionofoxoglutaratetosuccinyl-CoA,onemoleculeofNADHandonemoleculeofCO2 are formed.Succinyl-CoA is actedonby the enzyme succinyl-CoAsynthetase toformsuccinate.Duringtheconversionofsuccinyl-CoAtosuccinate,amoleculeofguanosinetriphosphate(GTP)isformedaswellasamoleculeofcoenzymeA(CoA).Thesearealsoremovedfromthecycle.The four-carbonmolecule succinate is further metabolized by the enzyme succinate dehydrogenase toform another four-carbon compound, fumarate. During the conversion of succinate to fumarate, twohydrogenionsandtwoelectronsareformed;thesetwoelectronsentertheelectrontransportchain.

9.B–AttheL1–L2sectionofthevertebralcanalThecaudaequinaisacollectionofnerverootsattheinferiorendofthevertebralcanalatapproximatelyL1–L2.Itcomestoanendatthislevelaswhilethespinalcordhaltsgrowthininfancy,thebonesofthespine continue to grow. There is some positional variation in adults. Lumbar punctures are thereforeperformedattheL3/4vertebralleveltopreventcomplicationssecondarytospinalcordtrauma.

10.D–PartofthepiamaterThepaireddenticulateligamentsofthepiamaterattachthespinalcordtothearachnoidandduramaterat21 positions on each side. They are important in providing stability to the spinal cord by preventingmotionwithinthevertebralcolumn.

11.D–TheyinhibitpeptidoglycansynthesisVancomycinisanexampleofaglycopeptideantibioticthatinhibitspeptidoglycansynthesis.Glycopeptideantibiotics are toxic (particularly nephrotoxic), are ineffective against Gram-negative organisms and,while theyarebacteriostaticagainstmost species, theyareonlybactericidalagainst enterococci.Theywillnotpenetrateintothecerebrospinalfluid.

12.E–PosteriorwhitecolumnsThefasciculusgracilis(ortractofGoll) is thebundleofaxonalfibreswhichcarriesinformationaboutfinetouch,vibrationandconsciousproprioceptionfromthelowerpartofthebodytothebrainstem.Itisfound in the posterior white columns (or the dorsal column–medial lemniscus pathway). Morespecifically, the fasciculus gracilis is foundmedially and the fasciculus cuneatus is found laterally. Itincreasesinsizeasthecolumnmovesupwards,asitcollectsandcarriesmorefibres.

13.E–SubmucosaMeissner’s plexus (submucosal plexus) is foundwithin the submucosa and is formed by the brancheswhich come from themyenteric plexus and have perforated the circularmuscle fibres. They innervatecells within the epithelium and the smooth muscle layer. It only contains parasympathetic fibres, incontrasttoAuerbach’splexuswhichcarriesbothsympatheticandparasympatheticinnervation.

14.A–MucosaThemucosaistheinnermostlayerofthegastrointestinaltract.Gut-associatedlymphoidtissue(GALT)isthedigestivetract’simmunesystemandisprimarilyfoundinthemucosa,althoughitsometimesextendsintothesubmucosa.Thesubmucosacomprisedenseirregularconnectivetissue.Withinthesubmucosaarethelymphaticvesselsandnerveplexuses.Meissner’splexusislocatedinthesubmucosa.Themuscularisexterna consists of thick layers of smoothmuscle.Themyenteric plexus ofAuerbach is located in themuscularisexterna.

15.D–StratifiedsquamousepitheliumTheoesophagusislinedwithnon-keratinizingstratifiedsquamousepithelium.Theseareflat(squamous)scale-likecellswhicharelayered(stratified)butnotkeratinized.Itallowssomeresistancetoextremesoftemperatureandtexture.Simpleepitheliahaveonlyonelayer.

16.A–L1Thepylorusofthestomach(astrongringofsmoothmuscle)isatthelevelofL1inthetranspyloricplane(ofAddison)and isgenerallyon the rightside. It is theconnectionbetween thedistal stomachand theduodenum.

17.A–NADHandCO2Thesix-carbonmoleculeofisocitrateisactedonbytheenzymeisocitratedehydrogenasetoformthefive-carbon compound oxoglutarate. During the conversion of isocitrate to oxoglutarate, one molecule ofNADHandonemoleculeofCO2areformed.

18.D–Theyinhibitthetranslocationofthepeptidyl-tRNAAminoglycoside antibioticswork by binding to the bacterial 30S ribosomal subunitwhich inhibits thetranslocationof thepeptidyl-tRNAfrom theA-site to theP-site.Thismeans thebacterium isunable tosynthesize proteins vital to its growth. They are ototoxic and nephrotoxic. They are effective againstGram-positiveandGram-negativebacteria.Theyareneveradministeredorallybutthroughintramuscularorintravenousinjection.

19.B–OxaloacetateOxaloacetateisafour-carbonmolecule.Itreactswithatwo-carbonmoleculeofacetyl-CoAtoformthesix-carbon compound citrate.At this point in the citric acid cycle, onemolecule of carbon dioxide isremovedtoformthefive-carboncompoundoxoglutarate.Anothercarbondioxidemoleculeisremovedatthis point to form the four-carbon compound succinate, which is converted via oxidation back intooxaloacetatesothatitcanbereusedinanotheriterationofthecitricacidcycle.

20.B–ThediaphragmaticpleuraisinnervatedbythevagusnerveThediaphragmaticpleuraisinnervatedbythephrenicnerve.Thevisceralpleuraonlyhastheautonomicinnervations of the vagus nerve and perceives stretch but not pain. Both visceral and diaphragmaticpleuraearereceptivetopain.

21.B–DuramaterThere are three layers covering the spinal cord.Fromoutermost to innermost, theyare theduramater,arachnoidmaterandpiamater.

22.E–HyponatraemiaPotassiumandmagnesiumarebothintracellular ionsrequiredforadequatecardiaccellfunctioningandstabilizationofthecardiaccellmembrane.Increasesordecreasesintheseionsmakecardiaccellsmorevulnerable to abnormal function, and therefore electrical disturbance, resulting in life-threateningarrhythmias.

23.E–PyruvatePyruvateismetabolizedbypyruvatedehydrogenasetoformacetyl-CoA.Pyruvatecanalsobeactedonbyanother enzyme, pyruvate carboxylase, to formoxaloacetate,which is an important intermediary in the

tricyclic acid (TCA) cycle. Acetyl-CoA is a two-carbon compound that binds with the four-carboncompoundoxaloacetate,viacitrate synthase, to formcitrate.Citrate is thenmetabolizedby theenzymeaconitasetoanintermediatecompoundcalledcis-aconitatebyremovingawatermolecule.cis-Aconitateisfurthermetabolizedbytheenzymeaconitaseandisconvertedtoisocitratebyaddingawatermolecule.Isocitrateisstillasix-carboncompoundbutithasbeenstructurallyalteredbytheremovalandadditionofa water molecule. Isocitrate is converted into the five-carbon compound oxoglutarate by the enzymeisocitratedehydrogenase.Duringtheconversionofisocitratetooxoglutarate,onemoleculeofNADHandonemoleculeofCO2areformed.

24.D–MagnesiumPotassium channels are inhibited bymagnesium.When plasma levels ofmagnesium are low, a higherconcentration of potassium moves into the extracellular spaces and is subsequently excreted by thekidneys.

25.D–MultipleburnsAnyconditioncausingtheexcesslossofwaterincomparisontosodium(e.g.burns,diarrhoea)willresultinhypernatraemia,aswillexcessiveuseofNaClforIVfluidreplacement.OveruseofIVdextrosefluiduseandSIADHwilldecreaseplasmalevelsofsodium.ACEinhibitormedicationinpatientswithrenalarterystenosiscanresultinacuterenalfailure,producinghyperkalaemiabutnothypernatraemia.

26.A–CitratewithinbloodproductsbindsplasmacalciumCitrate is contained within blood products in order to prevent coagulation. This binds to calcium,resulting in hypocalcaemia. Transfused red blood cells do not contain albumin. If a patient washypocalcaemicfromlowdietaryintake,assumingadequateparathyroidfunction,increasesinparathyroidhormonelevelswouldstimulatecalciumresorptionfrombonetocorrectthis.

27.E–LithiumLithiumisusedinthetreatmentofbipolardisorderanddepression.Onemustbeawareofitsnumerousside-effects including toxicity to the thyroid gland, which may result in the development ofhypothyroidism. It is therefore recommended that patients taking lithium have regular check-ups tomonitorforsymptomsofhypothyroidismaswellasbloodtestsforthyroidstatusmonitoring.

28.B–Bendroflumethiazide2.5mgodThiazide diuretics (and other non–potassium-sparing diuretics) are a common cause of hypokalaemiawithintheelderlypopulationbeingtreatedforhypertensionandcardiacfailure.Stoppingomeprazoleandaspirin would have no effect on plasma potassium. The patient may be taking cyclizine to preventpersistent vomiting, which could be the cause of his hyponatraemia. Spironolactone is an aldosteroneantagonistandthereforeispotassium-sparing.

29.B–InnermembraneATPsynthaseisfoundintheinnermembraneofmitochondriatoallowforthegenerationofATPinthematrix.

30.B–AmediallongitudinalfasciculuslesionDamagetothemediallongitudinalfasciculuscausesinternuclearophthalmoplegia.Thisischaracterizedbyweakness inadductionof the ipsilateraleyewithnystagmusonabducting thecontralateraleye. It isclassicallyseeninmultiplesclerosis.

31.A–CristaeCristaeare the internal folds formedby the innermembraneofmitochondria.Theyallowan increasedsurface area for aerobic respiration to take place. For example, the inner membranes of hepaticmitochondriahavefivetimestheactiveareawhencomparedtotheoutermembranes.

32.C–GammatubulinGammatubulinisfoundincentrosomesandactsasanucleatingsiteformicrotubuleassembly.α-andβ-tubulinbecomedimersandareassembledtoformmicrotubules.

33.E–RadioiodineRadioiodineisanabsolutecontraindicationinpregnancy.Theotherdrugslistedareallsafebutmustbeusedwithcaution inpregnancy.Carbimazoleandpropylthiouracilshouldbeusedwith the lowestdosepossible tocontrolsymptoms,as theybothmaycross theplacentaand thereforehigh levelsmaycausefetalhypothyroidism.

34.D–Sympatheticoveractivityofsmoothmuscle;carbimazoleSympathetic overactivity of smoothmuscle causes lid retraction and proptosis (anterior bulging of theeye)inhyperthyroidism.Proptosismaypreventtheeyesfromclosingproperly,whichcancausecornealscarringandoedematousconjunctiva.Carbimazoleshouldbeusedfirstasthistreatstheunderlyingcauseofhyperthyroidism.Topicaltreatmentsforimmediatesymptomaticreliefmayalsobeadministered,e.g.lubricatingeyedropsorsteroidstohelpreduceinflammation.

35.A–CarbimazoleAgranulocytosisisararetoxicside-effectofcarbimazoletherapy.Beforetherapyiscommenced,patientsshouldbeadvisedtostopthedrugandseekmedicaladviceifanysymptomssuchasfever,sorethroatormouth ulceration occur. Eventually, serious systemic infections can arise due to lack of neutrophils,causing a compromise in immunological defence. Propylthiouracil can be initiated instead, althoughsymptomsmaystillarisewiththismedicationandthereforesimilaradviceshouldbegivenwhenstartingthisdrug.

36.A–AminoglycosidesAminoglycosides, such as gentamicin, are useful in treating Gram-negative sepsis. Tetracyclines andmacrolidesareeffectiveagainstGram-negativebacteriabutnotaseffectiveasanaminoglycosideduringsepsis.OxazolidinonesandpenicillinsarenoteffectiveagainstGram-negativebacteria.

37.A–Effectiveat1/10ofthedoseofwhatwouldbeneededifgivenseparatelySulphamethoxazoleandtrimethoprimcombinetoformco-trimoxazole.Thesulphonamidepartofthedrugacts against folate synthesis at an earlier stage than most other antibiotics. Therefore, when incombination,thedrugsareeffectiveat1/10ofwhatwouldbeneededifeachdrugwasgivenonitsown.

38.B–LincosamidesLincosamides,suchasclindamycin,areactiveagainstGram-positivecocci.Theyinhibitproteinsynthesisin bacterial cells only bydisrupting ribosomal activity.Use clindamycinwith care, as itsmost severecommonside-effectisClostridiumdifficile–associateddiarrhoea.

39.D–VirusViral upper respiratory tract infections (URTIs) are the most common. Species such as rhinovirus,parainfluenzavirus,coronavirus,adenovirus,respiratorysyncytialvirusandtheinfluenzavirusaccount

formostcauses.HenceformostcausesoftrueURTIs,antibioticswillbecontraindicated.

40.E–RhinovirusRhinovirusis themostcommoncausativeviral infectiveagentofanURTI.It isasingle-strandedRNAvirusandisimplicatedinupto50%ofURTIs.

41.D–PolycythaemiarubraveraPolycythaemia rubra vera is a myeloproliferative disorder, commonly associated with erythroidhyperplasia, thrombocytosis and splenomegaly. Patients initially present with plethora but can presentuncommonlywitherythematous,warmorpainfulburningdistalextremities.

42.A–AsymmetricalhearinglossAnacousticneuromaisabenignschwannomaofthevestibularnervethatpresentswithanasymmetricallossofhearingandvertigopresentinglaterinthecourseofdisease.Withprogression,ipsilateralcranialnervesV,VI,IX,andXmaybecomeinvolved.TheypresentbilaterallyintypeIIneurofibromatosisandaccountfor80%ofcerebello-pontineangletumours.

43.C–ItisanacquiredconditionAparalyticsquint(orincomitantstrabismus)isanacquireddefectthatissaidtoexistwhentheangleofthedeviationvarieswiththedirectionofgaze.Whenthenormaleyeisfixingonanobject,thedegreeofstrabismusshownby theothereye is termed‘primary’deviation.When theabnormaleye is fixing, theangleofsquintisgreaterandisreferredtoas‘secondary’deviation.

44.D–50%TheRasproto-oncogeneismutatedinapproximatelyoneoutoffourhumancancers(25%).TheRasgeneis a family of genes which encode small GTPases that are involved in cellular signal transduction.ActivationofRassignallingpromotescellgrowth,differentiationandcell survival.Rascommunicatessignalsfromoutsidethecelltothenucleus,andmutationsinRasgenescanresultinpermanentactivation.Thisresultsininappropriatetransmissioninsidethecell.Becausethesesignalsleadtocellgrowthanddivision,dysregulatedRassignallingcanleadtooncogenesisandtumourformation.

45.B–ConnsyndromeConnsyndromeisprimaryhyperaldosteronism(i.e.occursindependentoftherenin–angiotensinsystem).Aldosterone acts within the kidney to retain sodium at the expense of potassium, thereforehyperaldosteronismcauseshypokalaemia.Addisondiseaseiscausedbydestructionordysfunctionoftheadrenal cortex. This reduces the amount of aldosterone produced and secreted, resulting inhyperkalaemia.Becausepotassium is an intracellular cation, anyprocess causing cell destruction (e.g.rhabdomyolysis, lysis of stored redbloodcells for transfusion)will release excesspotassium into theplasma.Inacidosis,excessH+ionsaretransportedintothecellsinexchangeforK+ions,whichthereforeincreaseK+ionconcentrationwithintheplasma.

46.C–GTPaseproteinsTheRasgenecodesforGTPaseproteins.GTPaseproteinstransmitsignalsfromthecellsurfacegrowthfactorreceptors.ActivationofRassignallingcausescellgrowth,differentiationandsurvival.MutationinRasgenescancausepermanentactivationresultinginuncontrolledcellgrowthanddifferentiation,andassuchcanleadtotumourformation.

47.B–Leberhereditaryopticneuropathy

Leber hereditary optic neuropathy (LHON) is a mitochondrial inherited disorder that leads to thedegenerationof retinalganglioncells. Itmainlyaffectsyoungmenandpresentswithacute-onsetvisuallossinfirstoneeye,andthentheother.

48.C–MénièrediseaseMénièrediseasecausesasensorineuralhearingimpairment.Itpresentswithrecurrentattacksofvertigo,fluctuatingsensorineuralhearingimpairmentandtinnitus,andiscausedbyendolymphatichydrops.It istreatedwithrest,reassuranceandantihistamines.Inseverecases,endolymphaticsacsurgeryorablationofthevestibularorganmaybeconsidered.

49.D–IsalwaysactiveMutations in theRas gene produce a protein that is always active, evenwhen there is no stimulatingsignalfromgrowthfactorreceptors.Thisresultsincellproliferationthatisuncontrolled.

50.A–MalateFumarateisafour-carboncompoundandisanintermediarymoleculeinthecitricacidcycle.Fumarateisacted on by fumarate hydratase to form a four-carbon compoundmalate.During this reaction, awatermoleculeisadded.Malateismetabolizedbytheenzymemalatedehydrogenaseintooxaloacetate.Duringtheconversionofmalatetooxaloacetate,amoleculeofNADHisformed.Oxaloacetateisafour-carboncompound and is combined with acetyl-CoA via the enzyme citrate synthase to form the six-carboncompoundcitrate.

QuestionsPaper51.Whichpartofabloodvesselplaysakeyroleinmediatingchemicalsignalswhichcontrolvasculartone?

A. Adventitia

B. Elasticainterna

C. Endothelium

D. Intima

E. Media

2.Whichoneofthefollowingstatementsregardinglymphocytesistrue?

A. B-lymphocytesfunctionbyactingdirectlyagainstvirus-infectedcellsandtumourcells

B. B-lymphocytesgiverisetoplasmacells

C. B-lymphocytesproduceplasmacells,whichproduceantigens

D. Lymphocytesarefoundmainlyintheplasma

E. T-lymphocytesgiverisetoplasmacells

3.TheactivationofC3byC3convertasecanoccurviathreepathways.Whichofthefollowingpathwaysbelowdescribesactivationviaantibodybindingtobacteria?

A. Alternativepathway

B. Apoptosis

C. Classicalpathway

D. Lectinpathway

E. Tyrosinekinasepathway

4.Whichoneofthefollowingisresponsibleforkneeflexionandankleplantarflexion?

A. Bicepsfemoris

B. Gastrocnemius

C. Popliteus

D. Rectusfemoris

E. Tibialisanterior

5.Howmanypairsofcervicalnervesarethereinthehumanspinalcord?

A. 7

B. 8

C. 9

D. 10

E. 11

6.Whichofthefollowinginitiatestheprocessofplateletaggregation?

A. ActivationofplateletsandsubsequentgenerationofarachidonicacidandsynthesisofthromboxaneA2

B. Adhesionofplateletstothrombogenicsurfaces

C. Exposureofvesselwallcollagen

D. ExpressionofglycoproteinIIb/IIIareceptors

E. PlateletaggregationwithfibrinogenbindingtoglycoproteinIIb/IIIa

7.Penicillinsbelongtowhichgroupofantibiotics?

A. Aminoglycosides

B. β-Lactams

C. Carbapenems

D. Lincosamides

E. Tetracyclines

8.WhichoneofthefollowingstatementsistrueregardingvitaminB12therapy?

A. VitaminB12canonlybeadministeredorally.

B. VitaminB12isindicatedforthetreatmentofanaemiaofchronicrenalfailure.

C. VitaminB12isindicatedforthetreatmentofperniciousanaemia.

D. VitaminB12isnotrequiredforDNAsynthesis.

E. VitaminB12treatmentrequiresregularweeklyinjectionsforlife.

9.Whichoneofthefollowingblockscalciumchannelsdirectly,inhibitingtheinfluxofCa2+intosmoothmusclecells?

A. Amlodipine

B. Diazoxide

C. Doxazosin

D. Glyceryltrinitrate

E. Ramipril

10.Whichoneofthefollowingmajorvesselsconsistentlycarriesdeoxygenatedblood?

A. Ascendingaorta

B. Brachiocephalictrunk

C. Pulmonaryartery

D. Pulmonaryvein

E. Thoracicaorta

11.Whichoneofthefollowingstatementsistrueregardingthedrugaspirin?

A. AspirinactivatesantithrombinIII,whichlimitsbloodclottingbyinactivatingthrombinandfactorX.

B. Aspirininhibitsplateletaggregation.

C. Aspirinisanantifibrinolyticagent.

D. Aspirinisoriginallyderivedfromtherubberplant.

E. Aspirinisrecommendedasananalgesicinchildrenlessthan12yearsofage.

12.Whichofthefollowingveinanastomoseswiththeazygoussystemofveins?

A. Hepaticvein

B. Leftgastricvein

C. Portalvein

D. Splenicvein

E. Superiormesenteric

13.Phagocytosisrequirestheattachmentofaphagocytetoanoffendingorganism.Onewaythisisdoneisviaopsonization.Whichoneofthefollowingdoesnotactasanopsonin?

A. Collectin

B. Complement

C. E-selectin

D. IgA

E. IgG

14.Whichofthefollowingvesselscarriesbloodfromtheliverintotheinferiorvenacava?

A. Hepaticvein

B. Leftgastricvein

C. Portalvein

D. Splenicvein

E. Superiormesenteric

15.Whichofthefollowingvessels’toneistheprincipaldeterminantofsystemicvascularresistance?

A. Arteriole

B. Artery

C. Capillary

D. Vein

E. Venule

16.Whichoneofthefollowingstatementsismostaccurateregardingfolicacid?

A. Folatedeficiencyresultsinmicrocyticanaemia.

B. FolateisnotrequiredforDNAsynthesis.

C. Folicacidisadministeredbyintramuscularinjections.

D. Folicacidsupplementsareassociatedwithmanyunpleasantside-effects.

E. Sincetheintroductionoffolicacidsupplementsforpregnantwomen,therateofneuraltubedefectsinnewbornbabieshasfallenmarkedly.

17.Tetracyclinesaffectwhichpartofabacterium?

A. TheycauseanticodonrecognitionwhichleadstothemisreadingofDNA.

B. Theycauseprematureterminationofthepeptidechain.

C. TheycompetewithtRNAfortheA-site.

D. Theyinhibittranslocation.

E. Theyinhibittranspeptidation.

18.WhichoneofthefollowingclassesofantimicrobialinhibitsDNAtopoisomeraseII?

A. Aminoglycosides

B. Fluoroquinolones

C. Lincosamides

D. Macrolides

E. Penicillins

19.Whichoneofthefollowingstatementsregardingironistrue?

A. Approximately25%ofthebody’sironsupplyisinhaemoglobin.

B. Intheblood,ironistransportedlooselyboundtoatransportproteincalledferritin.

C. Ironisstoredinsidecellsasprotein–ironcomplexessuchastransferrinandhaemosiderin.

D. Smallamountsofironarelosteachdayinurineandperspiration.

E. Theaveragedailylossofironis1mginwomenandmen.

20.Ethambutoliseffectiveagainstwhichofthefollowingorganisms?

A. Haemophilus

B. Mycobacterium

C. Neisseria

D. Staphylococcus

E. Streptococcus

21.Whichofthefollowingclassesofbiochemicalreactionsisthebesttargetforchemotherapy?

A. ClassI

B. ClassII

C. ClassIII

D. ClassIV

E. ClassV

22.Whichoneofthefollowingantibioticsinhibitsfolatesynthesis?

A. Aminoglycosides

B. Lincosamides

C. Penicillins

D. Sulphonamides

E. Tetracyclines

23.Whichofthefollowingstatementsregardingthalassaemiasistrue?

A. Itisassociatedwithareducedriskofinfection.

B. Itiscausedbyabsentorfaultyalphaandbetaglobinchains.

C. Itiscausedbyabsentorfaultyalphaorbetaglobinchains.

D. ItistypicallyseeninpeopleofNorthEuropeanancestry.

E. Sicklecellanaemiaisoneofthemanyvariantsofthalassaemia.

24.Whichoneofthefollowingisaβ-lactamaseinhibitor?

A. Benzylpenicillin

B. Ciprofloxacin

C. Clavulanicacid

D. Clindamycin

E. Piperacillin

25.Opsonizationismediatedbywhichofthefollowingcomponentsofthecomplementcascade?

A. C3a

B. C3b

C. C5a

D. C6

E. C7

26.Whichoneofthefollowingstatementsregardingthevasculatureofthekidneyiscorrect?

A. The arterial supply of the kidneys arises via one common renal artery which branches from theabdominalaorta.

B. Thekidneysaresuppliedbybranchesofthecoeliacartery.

C. Thepairedrenalarteriesarisefromtheabdominalaortabeneaththeinferiormesentericartery.

D. Therenalarteriessubdividetoforminterlobar,arcuateandinterlobulararteries.

E. Therightrenalveinreceivestherightgonadalveinbeforedrainingtotheinferiorvenacava.

27.Inordertoinduceosmoticcelllysis,theterminalcomponentsofthecomplementcascadeproduce:

A. Amembraneattackcomplex

B. Elastaseenzyme

C. Hydrogenperoxide

D. Lipopolysaccharide

E. Reactiveoxygenspecies

28.WhichofthefollowingclassesofdrugpreventsthenegativesupercoilingofDNA?

A. Aminoglycosides

B. Fluoroquinolones

C. Lincosamides

D. Macrolides

E. Penicillins

29.Which components of the complement cascade are known as anaphylatoxins due to their ability toinducehistaminereleasebymastcells,andtherebyvasodilation?

A. C3aandC5a

B. C3bandC5b

C. C6andC7

D. C6andC9

E. C7andC9

30.Whichofthefollowingstatementsisnottrueregardingfolicaciddeficiencyanaemia?

A. Inthebonemarrowitcausesaformofmegaloblasticanaemia.

B. Itisassociatedwithneurologicaldamage.

C. Itcommonlyoccursindietarydeficiency.

D. Itmaybeduetoalcoholism.

E. Itmaybeduetocoeliacdisease.

31.ComplicationsofvitaminB12deficiencyincludeallofthefollowingexcept:

A. Breathlessness

B. Glossitis

C. Perniciousanaemia

D. Reducedmyelinproductioninthespinalcord

E. Reversibleneurologicaldamage

32.Avascularnecrosismostcommonlyoccursatwhichanatomicallocation?

A. Anteriorsuperioriliacspine

B. Femoralhead

C. Headofthefifthmetatarsal

D. Maxillaryprocess

E. Mid-shaftofthehumerus

33.Whichoneofthefollowingstatementsabouthumanhaemoglobinisnottrue?

A. Carbondioxidecomplexeswithhaemoglobintoformcarboxyhaemoglobin

B. Eachhaemgroupbearsanatomofiron.

C. Haemoglobindoesnotexistfreelyintheplasma.

D. Normalvaluesforhaemoglobinare13–18g/100mLinanadultmale.

E. Theglobinpartofthehaemoglobinmoleculeconsistsoffourpolypeptidechains.

34.Regardingthecompositionofplasma,whichoneofthefollowingiscorrect?

A. Albuminaccountsfor36%ofplasmaproteins.

B. Fibrinogenaccountsfor14%ofplasmaproteins.

C. Globulinscontributeto60%oftheplasmaproteins.

D. Plasmaproteinscarrythyroidhormones.

E. Watercontributesto10%ofthetotalplasmavolume.

35.Whichoneofthefollowingelectrolytesisfoundathigherconcentrationswithintheextracellularfluidcomparedtotheintracellularfluid?

A. Ca2+

B. K+

C. Mg2+

D. Na+

E. PC42−

36.Whichoneofthefollowingstatementswithregardtobasophilsistrue?

A. Basophilsarethemostcommonwhitebloodcell.

B. BasophilsbindspecificallytoimmunoglobulinA.

C. Themostimportantroleofbasophilsistoleadthecounterattackagainstparasiticworms.

D. Theirnucleuscontainshistaminegranules.

E. StainedbasophilshaveU-shapednuclei.

37.Whichoneofthefollowingisthenarrowestpartofthemaleurethra?

A. Membranousurethra

B. Preprostatic(intramural)urethra

C. Prostaticurethra

D. Proximalurethra

E. Spongyurethra

38.Whichofthefollowingstatementsaboutthesecretionofvasopressiniscorrect?

A. Adecreaseinplasmavolumewillcauseanindirectinhibitionofvasopressinrelease.

B. Osmoreceptors within the brainstem detect changes in plasma osmolality and cause release ofvasopressin.

C. Oxytocinandvasopressinaresynthesizedwithinthecellbodyofthesameneurons.

D. Vasopressinissecretedfromtheanteriorpituitarygland.

E. Vasopressinreleaseisstimulatedbyanincreaseinplasmaosmolality.

39.Whichoneofthefollowingstatementsdescribingerythropoietinisincorrect?

A. Blood-borneerythropoietinstimulatesthespleentoproducemoreerythrocytes.

B. Erythropoietinisaglycoproteinhormone.

C. Erythropoietinisproducedbytheliverandkidneys.

D. Hypoxiastimulatestheproductionoferythropoietin.

E. Peoplelivingathigheraltitudeshaveincreasedratesoferythropoietinproduction.

40.Regardingbodywateranditsdistribution,whichofthefollowingstatementsiscorrect?

A. Approximatelytwo-thirdsoftotalbodywaterisintracellular.

B. Atleast90%ofaninfant’sbodymassiscomposedofwater.

C. Extracellularfluidislocatedprimarilywithintheintravascularandinterstitialspaces,themajorityofwhichiscontainedwithintheintravascularplasma.

D. Femaleshaveahigherpercentageofbodywaterincomparisontomales.

E. Theaverageperson’splasmavolumeis6L.

41.Acrosssectionthroughaparticularpointofthespinalcordshowsalargergreymatter(butterfly)areacomparedwiththewhitemater.Atwhichpointofthecordhasthissectionbeencut?

A. Cervical

B. Coccygeal

C. Lumbar

D. Sacral

E. Thoracic

42.Whichofthefollowingmakeupthetwomainmusclesofthepelvicfloor?

A. Thecoccygeusandtransversusani

B. Thelevatoraniandcoccygeus

C. Thelevatoraniandinternaloblique

D. Theobturatorinternusandexternaloblique

E. Therectusabdominisandinternaloblique

43.Theextensorsoftheforearmattachdistallytowhichbonystructure?

A. Theacromion

B. Thecoronoidprocess

C. Thedistalthirdoftheclavicle

D. Thelateralepicondyle

E. Themedialepicondyle

44.Whichmuscleofthepelvisisthemostpowerfulhipflexorandarotatorofthethigh?

A. Adductorlongus

B. Gluteusmaximus

C. Gracilis

D. Iliopsoas

E. Sartorius

45.Theconductingzoneoftherespiratorytractinvolvesallofthefollowing,except:

A. Bronchi

B. Bronchioles

C. Respiratorybronchioles

D. Terminalbronchioles

E. Trachea

46.Whatpercentageofcorticospinalfibrespassdowntheanteriorcorticospinaltract?

A. 5%

B. 15%

C. 50%

D. 75%

E. 80%

47.Whichofthefollowingmacroscopicgroovesonthesurfaceofthespinalcordisthemostprominent?

A. Anteriorlateralfissure

B. Anteriormedianfissure

C. Lateralfissure

D. Posteriorlateralfissure

E. Posteriormedianfissure

48.Whichoneofthefollowingisnotanaccuratestatementregardingnormalhaemostasisinhumans?

A. Primaryhaemostasisoccursasaresultofexposedsubendothelium.

B. Primaryhaemostasisinvolvesplateletadhesionandaggregation.

C. Secondaryhaemostasisrequirestheactivationofplasminogen.

D. TheadhesionofplateletstodamagedvascularendotheliumismediatedbyvonWillebrandfactor.

E. TissuefactorcomplexeswithfactorVIIduringclotinitiation.

49.Whichofthefollowinglistscorrespondscorrectlytotheleukocytesinorderfrommostabundanttoleastabundant?

A. Lymphocytes,neutrophils,monocytes,eosinophils,basophils

B. Monocytes,neutrophils,lymphocytes,basophils,eosinophils

C. Neutrophils,lymphocytes,basophils,monocytes,eosinophils

D. Neutrophils,lymphocytes,eosinophils,monocytes,basophils

E. Neutrophils,lymphocytes,monocytes,eosinophils,basophils

50.Whichoneofthefollowingstatementsregardingplasmaproteinsisnottrue?

A. Areductioninplasmaproteinlevelscausesfluidtomoveintotissues.

B. Albuminsareformedintheliverandaretheleastabundantplasmaproteins.

C. Globulinsareproducedintheliverandbytheimmunesystem.

D. Plasmaproteinsarelargelyresponsibleforcreatingtheosmoticpressureofblood.

E. Plasmaproteinsmakeupabout7%oftheplasma.

AnswersPaper51.C–EndotheliumThethreelayersofabloodvessel,frominnermosttooutermost,aretheintima,mediaandadventitia.Theintima consists of the endothelium and subendothelial connective tissue. The endothelium is rich inchemical receptors, mediating systemic signals relating to blood vessel function. Just outside of thesubendothelial layer is the elastica interna. Themedia is rich in smoothmuscle cells, which regulatevasculartone.

2.B–B-lymphocytesgiverisetoplasmacellsB-lymphocytes(B-cells)giverisetoplasmacellswhichproduceantibodies(immunoglobulins).Mostofthe lymphocytes are found in the lymphnodes and spleen,with only a small proportion present in thebloodstream.T-lymphocytes(T-cells)actdirectlyagainstvirus-infectedcellsandtumourcells.

3.C–ClassicalpathwayIntheclassicalcomplementpathway,C1bindstotheFCportionofIgGorIgMantibodywhenboundtoanantigen.TheresultingcomplexisaC3convertase,whichcleavesC3toC3bandC3a.Thelectinpathwayis similar to the classical pathway and is initiatedbybindingofmannose-binding lectinontomannans(bacterial surfaceswithpolysaccharidescontainingmannose).The resultingcomplexagain formsaC3convertase.

4.B–GastrocnemiusGastrocnemiusisamemberofthesuperficialmusclesoftheposteriorleg.Alongwiththesoleusandtheplantaris, the gastrocnemius inserts via the Achilles tendon. It facilitates both knee flexion and ankleplantarflexion.Thegastrocnemiusissuppliedbythetibialnerve,abranchofthesciaticnerve.

5.B–8Thereare8pairsofcervicalnerves,12pairsof thoracicnerves,5pairsof lumbarnerves,5pairsofsacral nerves and 1 pair of coccygeal nerves. While the number of pairs of spinal nerves generallymirrorsthenumberofcorrespondingvertebrae,thecervicalspineisanexception,with8pairsofnervesfor7cervicalvertebrae.

6.D–ExpressionofglycoproteinIIb/IIIareceptorsPlateletaggregationisthoughttobeginwithaninjurytoavesselwallexposingthrombogenicvesselwallcollagen, to which platelets directly adhere. Activation of adherent platelets leads to synthesis of anumber of chemical mediators; crucial among these are arachidonic acid and thromboxane A2.Thromboxane A2 leads to platelet expression of GPIIb/IIIa receptors, the subsequent binding offibrinogenandplateletaggregation.

7.B–β-Lactamsβ-Lactamsarealargegroupofantibioticswhichrangefromthefirstdiscoveredpenicillintothenewerfourth-generationcephalosporinsandcarbapenems.Theotherslistedhavetheirownseparategroups.

8.C–VitaminB12isindicatedforthetreatmentofperniciousanaemiaVitamin B12 is required for effective erythropoiesis and DNA synthesis. It can be administeredintramuscularly and orally, and is indicated for the treatment of pernicious anaemia. Initial treatmentrequiresregularweeklyinjections,butonceserumvitaminB12isnormalizedinjectionsshouldbegivenat3-monthlyintervals.

9.A–AmlodipineAmlodipine is a direct calcium channel blocker. Current British Hypertension Society and NICEguidelines suggest that either a calcium channel blocker or a thiazide diuretic is used as the first-linetherapyforessentialhypertension in individualsagedover55,or in thoseofAfro-Caribbeanoriginofanyage.Individualsagedunder55shouldbeinitiallytreatedwithanACEinhibitor.

10.C–PulmonaryarteryDeoxygenatedbloodisdeliveredtotherightsideoftheheartbythesuperiorandinferiorvenacavae.Onright ventricular contraction, deoxygenated blood is pumped into the lungs via the pulmonary artery.Oxygenatedblooddrainsintotheleftatriumviathepulmonaryveins,ofwhichtherearecommonlyfour.Oxygenatedbloodispumpedfromtheleftventricleintosystemiccirculationviatheaorta.

11.B–AspirininhibitsplateletaggregationAspirin(acetylsalicylicacid)wasoriginallyderivedfromthewillowtree.Childrenundertheageof12are at risk of developing Reye syndrome with aspirin. Aspirin is an antiplatelet agent. Heparin, notaspirin,activatesantithrombinIII.

12.B–LeftgastricveinOesophageal branches of the left gastric vein anastomose with oesophageal branches of the azygoussystem.Inthecontextofportalhypertension,theseanastomosescanformoesophagealvarices,whichintheeventofrupturecancausealife-threateningupperGIbleed.

13.C–E-selectinTheword ‘opsonization’ derives fromGreekopsonein – ‘to prepare for the table’. In the sameway,opsonizationofbacteriamakes themeasier to targetforphagocytosis.Collectinsareagroupofpatternrecognition receptors that bind to particular molecules on microbial surfaces and therefore act asopsonins independently of complement and antibodies. Mannose-binding lectin is an example of acollectin that recognizes carbohydrate units. Synergy between both antibody and complement providesstrongeropsonization,butbothcanfunctionindependently.E-selectinisareceptorfoundonendothelialcells,whichbindssialylatedoligosaccharideonleukocytestoencouragemarginationofleukocytesduringinflammation.

14.A–HepaticveinTheinferiormesentericveinjoinsfirstwiththesplenicvein,thenthesuperiormesentericvein,toformthe portal vein. The portal vein supplies asmuch as 75% of the liver’s blood supply (the remaindercoming chiefly from the hepatic artery). The left gastric vein also drains into the portal vein but alsoanastomoseswiththeazygoussystemaroundtheoesophagus.Bloodleavestheliverviathehepaticveinand drains into the inferior vena cava. Obstruction of the hepatic vein can give rise to Budd–Chiarisyndrome.

15.A–Arteriole

Vascularresistanceisdeterminedbythemuscularvesselsofthearterialsideofthebody’scirculation.Inparticular,thesmallerdiameterarteriolesarethechiefdeterminantofvascularresistance.

16.E–Sincetheintroductionoffolicacidsupplementsforpregnantwomen,therateofneuraltubedefectsinnewbornbabieshasfallenmarkedlyFolic acid is administered orally and has no contraindications or serious adverse effects. Folate isrequired for DNA synthesis and effective erythropoiesis. Folate deficiency can cause a macrocyticmegaloblasticanaemia.

17.C–TheycompetewithtRNAfortheA-siteTetracyclines are inhibitors of protein synthesis,where they specifically inhibit binding of aminoacyl-tRNA to the ribosome complex. Macrolides inhibit translocation. Aminoglycosides cause anticodonrecognitionwhichleadstothemisreadingofDNA.Chloramphenicolinhibitstranspeptidation.

18.B–FluoroquinolonesCiprofloxacin is a fluoroquinolone. These antimicrobials inhibit topoisomerase II – a DNA gyrase –whichconsequentlypreventsthenegativesupercoilingofDNA.

19.D–SmallamountsofironarelosteachdayinurineandperspirationSixty-fivepercentofthebody’sironsupplyisfromhaemoglobin.Ironisstoredinsidecellsasferritinandhaemosiderin.The iron-transport protein inblood is transferrin, not ferritin.The averagedaily lossofironis1mg,butthisishigherinpremenopausalwomenduetomenstruallosses.Basaldailyironlossesoccurinurineandsweat.

20.B–MycobacteriaThemechanismofactionofethambutolisunknown.However,ittakesupto24hoursbeforeitbeginstoinhibitgrowthofmycobacteria.Itcannotbeusedindependentlyasresistancequicklydevelops.

21.C–ClassIIIClass III reactions represent the best targets as these involve the assembly of small molecules intomacromolecules such as DNA and RNA. Class II represents the second best choice as these are thereactionswhichproducethesmallmoleculessuchasaminoacids.Adrugwhichactsonthisreactionisthe group of sulphonamides. Class I reactions are an unhelpful target as there is no great differencebetweenhumanandbacterialmechanisms.ClassesIVandVdonotexist.

22.D–SulphonamidesSulphonamides affect folate synthesis by inhibiting dihydropteroate synthetase. They are competitiveinhibitorsoftheenzyme.Whileitproducesdihydropteroateacidinbacteria,ithasnofunctioninhumans.Theothershavenoeffectonfolatesynthesis.

23.C–ItiscausedbyabsentorfaultyalphaorbetaglobinchainsThalassaemiasaretypicallyseeninpeopleofMediterraneanancestry,suchasGreeksandItalians.Itiscausedbyabsentorfaultyalphaorbetaglobinchains.Thalassaemiaisassociatedwithanincreasedriskofinfection.Therearemanysubtypesofthalassaemia,butsicklecelldiseaseisnotoneofthem.

24.C–ClavulanicacidClavulanic acid has very little antimicrobial action on its own; however, by inhibiting β-lactamase, itallowsotherantibioticstoworkagainstthosepathogenswhichhavedevelopedaresistancetoβ-lactam

antibiotics,forexampleco-amoxiclav.

25.B–C3bOpsonizationisaprocessbywhichmicrobeswithinthebodycanbehighlightedfordestructionbycellsoftheimmunesystem.ComplementC3baidsintheopsonizationofmicrobes.Thecomplementcascadeisversatileinthatdifferentcomponentsareabletoinitiatedifferentpartsoftheinflammatoryresponse.

26.D–Therenalarteriessubdividetoforminterlobar,arcuateandinterlobulararteriesThekidneysare suppliedby thepaired renal arteries,whichbranch from theabdominal aortadirectlybelow the superior mesenteric artery. The renal arteries subdivide into interlobar, arcuate andinterlobulararteries.Theafferentarteriolesformedfromtheinterlobulararteriessupplytheglomerularcapillarybed,whichsitsinsideBowman’scapsule,thesiteoffiltration.Therenalveinsdrainthekidneysintotheinferiorvenacava(IVC).BecausetheIVCliestotherightofthemidline,theleftrenalveinislongerandreceivestheleftsuprarenalvein,theleftgonadalveinandtheleftinferiorphrenicvein,whiletherightrenalveinenterstheIVCdirectlywithoutreceivingfurthertributaries.

27.A–AmembraneattackcomplexThemembraneattackcomplexisformedinfivemainstepsbycombiningcomplementcomponentsC5bthroughC9andactsbyinsertionofaporethroughthecellmembraneofitstarget.Thisporethenallowstheeffluxandinfluxofionsandsmallmolecules,includingwater.Reactiveoxygenspeciesandhydrogenperoxideproduceoxidativecelldamage,whichthentriggersdeathbyapoptosis.Elastaseisanenzymereleasedfromneutrophilgranulescausingdestructionviadigestion.Lipopolysaccharide,orendotoxin,isamoleculecontainedwithintheoutermembraneofGram-negativebacteria.

28.B–FluoroquinolonesCiprofloxacin is a fluoroquinolone. These antimicrobials inhibit topoisomerase II – a DNA gyrase –whichconsequentlypreventsthenegativesupercoilingofDNA.

29.A–C3aandC5aOveractivation of the anaphylatoxins C3a and C5a can result in unwanted levels of hypotension inresponsetoinfection.C5a,inadditiontoactingtoreleasehistamine,isinvolvedinleukocytechemotaxisandactivation.C3bbindsglycoproteinsonmicrobecellsurfacesandactsasanopsoninthroughspecificbinding to receptorsonmacrophagesandneutrophils.C5bservesasananchor for theformationof themembraneattackcomplex(MAC).

30.B–ItisassociatedwithneurologicaldamageFolicaciddeficiencyanaemiacausesaformofmegaloblasticanaemiaidentical to thatseeninvitaminB12deficiencybutnotassociatedwithneurologicaldamage.Itmaybeduetodietarydeficiency,e.g. inalcoholismandanorexia.

31.E–ReversibleneurologicaldamageVitaminB12 deficiency can lead to irreversible neurological damage. Pernicious anaemia is the mostcommonformofvitaminB12deficiency.Itoccursmoreofteninwomenthanmen,usuallybetween45and65yearsofage.

32.B–Femoralhead

Avascularnecrosis(orosteonecrosis)iscausedbyaninterruptionofbloodflowtothebone,resultinginnecrosisofthecortex,medullaryboneandmarrow.Thefemoralheadhaslimitedcollateralbloodsupplyandsodisturbanceof itsvasculaturecan result in ischaemiaand subsequentnecrosis.Thepatientmaypresentwithincreasinghippainandaninabilitytobearweight,followedbyprogressivelimitationintherange of movement of the joint. Limb shortening occurs when bone destruction ensues. Predisposingfactors to osteonecrosis include alcohol excess, corticosteroid therapy, neck of femur fracture,dislocation, sickle cell disease and disseminated malignancy. It can also occur following scaphoidfractures.

33.A–CarbondioxidecomplexeswithhaemoglobintoformcarboxyhaemoglobinHaemoglobin is contained in erythrocytes, rather than existing free in plasma. Carbon dioxide andhaemoglobin combine to form carbaminohaemoglobin. Carbon monoxide readily combines withhaemoglobintoformcarboxyhaemoglobin.Theothergivenstatementsaretrue.

34.D–PlasmaproteinscarrythyroidhormonesWater contributes to 90%of plasma volume. The plasma protein pool has the following composition:60% albumin, 36% globulins, 4% fibrinogen. Steroid and thyroid hormones are carried by plasmaproteins.

35.D–Na+Potassium is theprimarycationof the intracellular fluid.Phosphates, calciumandmagnesiumare alsofound in higher concentrations intracellularly than extracellularly. Sodium ions are the most abundantcationsoftheextracellularfluid.

36.E–StainedbasophilshaveU-shapednucleiBothbasophilsandmastcellsbindtoIgE.Eosinophilsfightagainstparasiticworms.Basophilsaretheleast abundantwhite blood cell. It is their cytoplasm that contains histamine granules.Basophils stainpurplish-black, and stained nuclei are generally U- or S-shaped with two or three conspicuousconstrictions.

37.A–MembranousurethraThemaleurethraisapproximately20cmlongandfacilitatesthepassageofurineandsemen.Itisdividedanatomically into four sections: the intramural (preprostatic or vesicular), prostatic, intermediate(membranous)and spongyurethra.Mostproximally, thepreprostaticurethra runsvertically through theneck of the bladder. The prostatic urethra then passes vertically through the anterior prostate. Themembranous,orintermediate,partoftheurethraisthenarrowestofthefourpartsandthereforethemostvulnerable to trauma at instrumentation (e.g. catheterization). The most distal and longest part is thespongy(cavernous)urethra,whichpassesthroughthecorpusspongiosumandendsinaslit-likeopening(theexternalurethralmeatus).

38.E–VasopressinreleaseisstimulatedbyanincreaseinplasmaosmolalityOsmoreceptors within the anterior hypothalamus detect changes in plasma osmolality and secretevasopressin(orantidiuretichormone[ADH])viatheposteriorpituitaryglandinresponsetoanincreasein plasma osmolality. Oxytocin and vasopressin are synthesized within different neurons to allowindependentrelease.Adecreaseinplasmavolume,detectedbythebaroreceptors,willcauseanincreaseinvasopressinrelease.Onceactivatedbyhypovolaemia,theincreaseinvasopressinisdramaticandmayoverride signals fromosmoreceptors in order tomaintainplasmavolume at the expenseof decreasingosmolality.

39.A–Blood-borneerythropoietinstimulatesthespleentoproducemoreerythrocytesErythropoietin is a naturally occurring hormonewhich ismainly produced by the liver and kidneys inresponsetohypoxicstress.Thishormonestimulatesthebonemarrowtoproducemoreredbloodcells.Thespleenisinvolvedinthebreakdownofoldredbloodcells.

40.A–Approximatelytwo-thirdsoftotalbodywaterisintracellularWater makes up a higher percentage of total body mass within males and infants (60% and 75%,respectively)thanitdoeswithinfemales(roughly50%).Thisisduetotherelativelyhigherpercentageofadipose tissue within women. Two-thirds of total body water (42 L) is contained within cells(intracellular).Oftheremainingextracellularfluid,themajorityisfoundwithintheinterstitialspaces,andonly3Loffluidisgenerallyfoundwithintheintravascularplasma.

41.D–SacralThegreymatter is largest in thesacralarea,andat thispoint itoccupiesasignificantlygreaterareaincross-section than the white matter. The grey matter contains neural cell bodies and is the majorcomponentofthecentralnervoussystem.Theareaofgreymatterincreasesasthespinalcorddescends.

42.B–ThelevatoraniandcoccygeusThemusclesofthepelvicfloorconsistofthelevatoraniandcoccygeus.Thelevatoraniismadeupoffourparts: levatorprostatae/vaginae,puborectalis,pubococcygeusandiliococcygeus.Thecoccygeus istheposteriormuscleof thepelvic floor.Levator ani canbedamaged inpregnancyandchildbirth.Thepelvic floormuscles canbeexercisedand tone improvedbyKegel exercises,whichcanhelppatientswithstressincontinenceandpotentiallyprotectagainstprolapse.

43.D–ThelateralepicondyleThelateralepicondyleistheattachmentofthecommonextensortendonoftheforearm.Inflammationofthelateralepicondyleisknownas‘tenniselbow’,whichresultsintendernessoverthelateralepicondyleandpainonwristextension.Itiscommoninactivitiesthatutilizerepetitivewristextension.Themedialepicondyle is the common flexor origin, and inflammation occurring here is known as medialepicondylitisor‘golfer’selbow’.

44.D–IliopsoasTheiliopsoasismadeupoftheiliacusandpsoasmajorandfacilitateshipflexionandexternalrotation.Thesartoriusmusclefacilitatessittingcross-legged,whilethegluteusmaximusextendsthehipalongwiththe hamstring muscles. Both the adductor longus and gracilis are responsible for adduction and aresuppliedbytheobturatornerve.

45.C–RespiratorybronchiolesTheconductingzoneoftherespiratorytract,whereconvectionofatmosphericgasestakesplace,includesthetrachea,bronchi,bronchiolesandterminalbronchioles.Thetransitionalandrespiratoryzones,wherediffusionofoxygenandcarbondioxidetakesplace,includerespiratorybronchioles,alveolarductsandalveolarsacs.

46.B–15%Atthepyramidaldecussation,80%ofcorticospinalfibrespassintothecontralaterallateralcorticospinaltract.Theremainingfibresremainuncrossed,with15%passingintotheipsilateralanteriorcorticospinaltractand5%descendingintheipsilaterallateralcorticospinaltract.

47.B–AnteriormedianfissureTheanteriormedianfissureisthemostprominentgrooveonthesurfaceofthespinalcord.Itisoccupiedby the anterior spinal artery.Theposteriormedian fissure is less prominent and is onlypresent in themedullaoblongata.Theanteriorandposteriornerverootletsemergeattheanteriorlateralandposteriorlateralfissures.Thelateral(Sylvian)fissuredividesthefrontalandtemporallobesfromtheparietallobe.

48.C–SecondaryhaemostasisrequirestheactivationofplasminogenPlasminogen is necessary for the process of fibrinolysis to occur, i.e. for clot regulation and removal.Plasminogeniscleavedbytissueplasminogenactivator(t-PA)tothefibrinolyticenzymeplasmin.Alltheotherstatementsregardinghaemostasisarecorrect.

49.E–Neutrophils,lymphocytes,monocytes,eosinophils,basophilsFrommost to least abundant, the leukocytes are: neutrophils, lymphocytes,monocytes, eosinophils andbasophils.Thefollowingphrasemayhelpyoutoremembertheorder:NeverLetMonkeysEatBananas.

50.B–AlbuminsareformedintheliverandaretheleastabundantplasmaproteinsPlasmaproteinsmakeuparound7%oftheplasmaandarelargelyresponsibleforcreatingtheosmoticpressureofblood. Ifplasmaprotein levels fall, becauseof either reducedproductionor loss from thebloodvessels,osmoticpressureisalsoreduced,andfluidmovesintotissues(oedema)andbodycavities.Albuminsarethemostabundantplasmaproteins,comprising60%ofthetotal.

QuestionsPaper61.Whatisthenameofthefour-carboncompoundthatisconvertedtooxaloacetateinthetricyclicacidcycle?

A. Acetyl-CoA

B. Citrate

C. Oxaloacetate

D. Oxoglutarate

E. Succinate

2.Whichoneofthefollowingstatementsregardingsicklecelldiseaseisleastaccurate?

A. Sicklecelldiseaseproducesshortenedredbloodcellsurvival.

B. Sicklecellhaemoglobin(HbS)resultsfromasinglebasemutation,whichproducesasubstitutionofvalineforthymine.

C. Sicklingmaybeprecipitatedbycold.

D. ThediseaseoccursmainlyinpeopleofAfricanorigin.

E. ThesinglebasesubstitutionofHbSoccursintheβ-globinchain.

3.WhichpartofthesmallintestinecontainsthemajorityoftheBrunnerglands?

A. Duodenum

B. Ileum

C. Jejunum

D. Alloftheabove

E. Noneoftheabove

4.Whichenzymeactsonoxaloacetateandacetyl-CoAinthecitricacidcycle?

A. Aconitase

B. Citratesynthase

C. Fumaratehydratase

D. Isocitratedehydrogenase

E. Succinatedehydrogenase

5.Bonemarrowcanbefoundinwhichtypeofbone?

A. Cancellous

B. Compact

C. Cortical

D. Lamellar

E. Woven

6.Citrateisasix-carboncompoundfoundintheKrebscycle.WhatothercompoundintheKrebscyclecontainssixcarbons?

A. Fumarate

B. Isocitrate

C. Malate

D. Oxoglutarate

E. Succinate

7.Whichoneofthefollowingisanopioidreceptor?

A. Gammareceptor

B. Lambdareceptor

C. Mureceptor

D. Omegareceptor

E. Sigmareceptor

8.Whichoneofthefollowingisasesamoidbone?

A. Femur

B. Humerus

C. Patella

D. Scaphoid

E. Tibia

9.Inthecitricacidcycle,succinyl-CoAisconvertedtosuccinatebywhichenzyme?

A. Succinyl-CoAcarboxylase

B. Succinyl-CoAdehydrogenase

C. Succinyl-CoAsynthetase

D. Succinyldehydrogenase

E. Succinylsynthetase

10.Whichofthefollowingisnotaphysiologicaleffectofnon-steroidalanti-inflammatorydruguse?

A. Analgesic

B. Anti-inflammatory

C. Antiplatelet

D. Antipyretic

E. Antispasmodic

11.Whichoneofthefollowingisaselectivecyclooxygenase-2inhibitor?

A. Aspirin

B. Diclofenac

C. Diflunisal

D. Ibuprofen

E. Rofecoxib

12.Whichpartofthesmallintestinecontainsthelongestvilli?

A. Duodenum

B. Ileum

C. Jejunum

D. Alloftheabove

E. Noneoftheabove

13.Whatisformedduringtheconversionofsuccinyl-CoAtosuccinateintheKrebscycle?

A. ADPandHSCoA

B. ATPandHSCoA

C. GDPandHSCoA

D. GMPandHSCoA

E. GTPandHSCoA

14.Whichoneofthefollowingstatementsregardingirondeficiencyanaemiaismostaccurate?

A. Around10%ofdietaryironisnormallyabsorbedthroughthestomach.

B. Bloodfilmappearancesincludehyperchromicmacrocyticcells.

C. ItiscommonlycausedbymalabsorptionintheWesternworld.

D. Koilonychiaisarecognizedfeature.

E. Serumferritinisraised.

15.Whichoneofthefollowingstatementsisnotaccurateregardingplatelets?

A. Themeanplateletdiameteris1–2μm.

B. Thenormalplateletcountrangeforallagesis150–250×109/L.

C. Theirnormallifespanis7–10days.

D. Theyareproducedpredominantlybythebonemarrowmegakaryocytes.

E. Storagegranuleswithintheplateletincludedensegranules.

16.Whichoneofthefollowingstatementsabouttheleftmainbronchusisincorrect?

A. Itdoesnotbranchuntilentryintothehilum.

B. Itgivesofftwobranches.

C. Itliesanteriortothedescendingaorta.

D. Itliesinferiortothepulmonaryartery.

E. Itliesposteriortotheoesophagus.

17.Whichoneofthefollowingstatementsregardingbloodcellsisnottrue?

A. Allbloodcellsarederivedfrompluripotentstemcells.

B. Bloodislandsareformedintheyolksacinthethirdweekofgestation.

C. Redcellssurviveonaverage120days.

D. Thebonemarrowbecomesthemainsourceofbloodcellsduringnormalchildhoodandadultlife.

E. Theliverandthekidneysarethechiefsitesofhaematopoiesisfrom6weeksto7months’gestation.

18.Whichofthefollowingisthemostcommoncauseofabdominalaneurysmaldisease?

A. Arteritis

B. Connectivetissueabnormality

C. Cysticmedialdegeneration

D. Infection

E. Trauma

19.Whichoneofthefollowingistrueregardingthespleen?

A. Bloodentersthespleenviathesplenicartery.

B. Itissituatedintherighthypochondrium.

C. Itisthesmallestlymphoidorganinthebody.

D. Itisunnecessarytoeducateallpatientsabouttheriskofinfectionaftersplenectomy.

E. Splenectomyisperformedmainlyforirondeficiencyanaemia.

20.Whichofthefollowingisindicatedasthefirst-lineanalgesicforapatientwithmigraine?

A. Codeine

B. Fentanyl

C. Methysergide

D. Morphine

E. Paracetamol

21.Aprimarychronicinflammatoryresponsecanbetriggeredinvariousways.Exposuretowhichoneofthefollowingwouldnotresultinaprimarychronicinflammatoryresponse?

A. Asbestosfibres

B. Mycoplasmatuberculosis

C. Poliovirus

D. Staphylococcusaureus

E. Uratecrystals

22.Whatissuppuration?

A. Ablindendingtractcommunicatingwithanepithelialsurface

B. Theaccumulationofpuswithinahollowviscuswithablockedoutflowtract

C. Theformationofanabnormalcommunicationbetweentwoepithelialsurfaces

D. Theformationofcellulardebriscomposedoflivinganddeadneutrophilsandbacteria

E. Thelocalaccumulationofpuswithinamembrane

23.Withrespecttobloodgroups,whichoneofthefollowingistrue?

A. TheABObloodgroupsysteminvolvesnaturallyoccurringIgGantibodies.

B. TheABOsysteminvolvesnaturallyoccurringIgManti-Aandanti-Bantibodies.

C. Thebloodgroupsaredeterminedbyantigensonthesurfaceofallcells.

D. ThemajorbloodgroupsareKell,DuffyandKidd.

E. TherhesusbloodgroupsysteminvolvesnaturallyoccurringIgMantibodies.

24.Whichofthefollowingisnotaside-effectofparacetamol?

A. Bradycardia

B. Hypotension

C. Leukopaenia

D. Rash

E. Thrombocytopaenia

25.Theplateletcountmayrisesignificantlyineachofthefollowingconditionsexcept:

A. Bonemarrowfailure

B. Hodgkinlymphoma

C. Majorsurgery

D. Splenectomy

E. Ulcerativecolitis

26.Theadenomatouspolyposiscoli(APC)genemarkswhatfordegradation?

A. α-Cartenin

B. α-Catenin

C. β-Cartenin

D. β-Catenin

E. δ-Cartenin

27.Whichoneofthefollowingistrueregardinghaemophilia?

A. HaemophiliaAisalsoknownasChristmasdisease.

B. HaemophiliaAisassociatedwithaprolongedbleedingtime.

C. HaemophiliaAisinheritedasanX-linkeddisorder.

D. HaemophiliaBiscausedbyadeficiencyoffactorVIII.

E. Haemophiliaisanacquiredcoagulationdisorder.

28.Whichoneofthefollowingtypesofboneispartoftheappendicularskeleton?

A. Pelvis

B. Ribs

C. Skull

D. Sternum

E. Vertebralcolumn

29.Whichoneofthefollowingcelltypesconnectstheperiosteumtothebone?

A. Merkelcells

B. Remakbundles

C. Schwanncells

D. Sharpeyfibres

E. Noneoftheabove

30.WithinwhichlayeristheAuerbach’splexusfound?

A. Laminapropria

B. Muscularisexterna

C. Muscularismucosa

D. Serosa

E. Submucosa

31.Whichoneofthefollowingisacharacteristicofbone?

A. ItcontainsmostlytypeIIcollagen.

B. Ithascalciumphosphateasitsmajorinorganicconstituent.

C. Itisdevoidofcells.

D. Itismostlycomposedofwater.

E. Itisstrongduetoitslamellarstructure.

32.Whichoneofthefollowingconstitutesacombinationofcodeineandparacetamol?

A. Co-codamol

B. Co-dydramol

C. Co-proxafol

D. Co-tramadol

E. Co-proxamol

33.Osteoidosteomascanarisefromwhichtissue?

A. Cortex

B. Medullarycavity

C. Periosteum

D. Alloftheabove

E. Noneoftheabove

34.Whatarethespiculesonspongybonecalled?

A. Canaliculi

B. Lacunae

C. Sharpeyfibres

D. Tomesprocess

E. Trabeculae

35.Whichoneofthefollowingisassociatedwithwithdrawalsymptoms?

A. Aspirin

B. Diclofenac

C. Hyoscine

D. Morphine

E. Paracetamol

36.Apatient isrecoveringfromalefthemicolectomy.Intheimmediatepostoperativeperiod,whichofthefollowingwouldbethemostappropriatemechanismofanalgesia?

A. Epidural

B. Non-steroidalanti-inflammatorydrug

C. Paracetamol

D. Syringedriver

E. Tramadolandmorphine

37.Whichofthefollowingisanorganiccomponentofbone?

A. Calciumphosphate

B. Hydroxyapatite

C. TypeIcollagen

D. Alloftheabove

E. Noneoftheabove

38.RegardingVolkmanncanals,whichoneofthefollowingstatementsistrue?

A. Theyarealmostexclusivelyfoundincancellousbone.

B. Theyareneverfoundincompactbone.

C. TheyrunparalleltoHaversiancanals.

D. TheyrunperpendiculartoHaversiancanals.

E. Noneoftheabove.

39.Whichoneofthefollowingisacardioselectivebeta-blocker?

A. Mannitol

B. Metoprolol

C. Propranolol

D. Sotalol

E. Verapamil

40.Whichoneofthefollowingisacontraindicationtotheuseofparacetamol?

A. Asthma

B. Drugabuse

C. Gastriculcer

D. Liverfailure

E. Uncontrolledbleeding

41.A57-year-oldmanwhohadanon-STelevationmyocardialinfarction4monthsagosubsequentlyhada stent inserted into his right coronary artery. He was initiated on aspirin, clopidogrel, ramipril,bisoprolol and atorvastatin. He is now having problems sustaining erections.Which drug ismostlikelyresponsible?

A. Aspirin

B. Atorvastatin

C. Bisoprolol

D. Clopidogrel

E. Ramipril

42.Pyrexia is a commonclinical signof acute inflammation.Whatphysiologicalmechanismunderliesthis?

A. Increasedcellularactivityandbasalmetabolicratewitharesultantreleaseofheat

B. Increasedsympatheticstimulationcausingincreasedsweating

C. IncreasedTSHreleasefromthepituitaryglandincreasingbasalmetabolicrate

D. Resettingofthehypothalamic–pituitaryaxistoincreaseACTHproduction

E. Resettingofthehypothalamicthermostatbyendogenouschemicals

43. Individuals with amutated p53 gene in their germ line have what increase in risk of developingcancer?

A. 5timesincrease

B. 10timesincrease

C. 25timesincrease

D. 35timesincrease

E. 50timesincrease

44.A64-year-oldmanwithseverecommunity-acquiredpneumoniaismostatriskofdevelopingwhichtypeofshock?

A. Anaphylacticshock

B. Cardiogenicshock

C. Hypovolaemicshock

D. Neurogenicshock

E. Septicshock

45. Which of the following features is more commonly associated with acute, rather than chronic,inflammation?

A. Fibrosis

B. Granulomaformation

C. Infiltrationofmacrophages

D. Infiltrationofneutrophils

E. Productionofinterferongamma

46.WhichpartofthesmallintestinecontainsthemajorityofthePeyer’spatches?

A. Duodenum

B. Ileum

C. Jejunum

D. Alloftheabove

E. Noneoftheabove

47.Whichoneofthefollowingmediatorsofinflammationisproducedbytheliver?

A. Complement

B. Nitricoxide

C. Prostaglandin

D. Serotonin

E. Tissuenecrosisfactor

48.Whichoneofthefollowingstatementsabouttherightmainbronchusisincorrect?

A. Itdescendsmoreverticallythantheleft.

B. Itdividesbeforeenteringthehilum.

C. Itgivesoffthreebranches.

D. Itisrelatedanteriorlytothesuperiorvenacava.

E. Itisrelatedinferiorlytotheazygousvein.

49.Whichoneofthefollowingstatementsaboutbronchopulmonarysegmentsisincorrect?

A. Adjacentsegmentsarecommunicating.

B. Eachlunghas10bronchopulmonarysegments.

C. Eachsegmenthasitsownneurovascularsupply.

D. Eachsegmentiswedge-shaped.

E. Therightlunghasthreesuperior,twomiddleandfiveinferiordiscretelyfunctioningsegments.

50.Whichpartofthesmallintestineislinedwithsimplecolumnarepithelium?

A. Duodenum

B. Ileum

C. Jejunum

D. Alloftheabove

E. Noneoftheabove

AnswersPaper61.E–SuccinateOxaloacetateisafour-carbonmolecule.Itreactswithatwo-carbonmoleculeofacetyl-CoAtoformthesix-carbon compound citrate.At this point in the citric acid cycle, onemolecule of carbon dioxide isremoved to form a five-carbon compound called oxoglutarate. Another carbon dioxide molecule isremoved to form the four-carbon compound succinate, which is converted via oxidation back intooxaloacetatesothatitcanbeusedagaininanothercycleofthecitricacidcycle.ThecitricacidcycleisalsoknownasthetricyclicacidcycleortheKrebscycle.

2. B – Sickle cell haemoglobin (HbS) results from a single base mutation, which produces asubstitutionofvalineforthymineHbSresultsfromasinglebasemutationofadeninetothymine,whichproducesasubstitutionofvalineforglutamineatthesixthcodonoftheβ-globinchain.Alltheotherstatementsgivenaretrue.

3.A–DuodenumBrunnerglandsarefoundinthesubmucosaoftheduodenum.TheyarecompoundtubularglandsfoundinthepartoftheduodenumproximaltothesphincterofOddi.Theirmainfunctionistoproduceanalkalinesecretion which protects the duodenum from acidic chyme (from the stomach) and which allowsfavourableconditionsforintestinalenzymes.

4.B–CitratesynthasePyruvateisactedonbypyruvatedehydrogenasetoformacetyl-CoA.Pyruvatecanalsobemetabolizedbypyruvatecarboxylasetoformoxaloacetate,whichisanimportantintermediaryintheTCAcycle.Acetyl-CoAisatwo-carboncompoundthatbindswiththefour-carboncompoundoxaloacetate,viatheenzymecitratesynthase,toformthesix-carboncompoundcitrate.Citrateisthenactedonbytheenzymeaconitase,whichconvertsthecitratetoanintermediatecompound,cis-aconitate,byremovingawatermolecule.cis-Aconitateisfurthermetabolizedbytheenzymeaconitaseandisconvertedtoisocitratebyaddingawatermolecule.Isocitrateisstillasix-carboncompoundbutithasbeenstructurallyalteredbytheremovalandaddition of a water molecule. The six-carbon molecule of isocitrate is acted on by another enzyme,isocitrate dehydrogenase, to form the five-carbon compound, oxoglutarate. During the conversion ofisocitratetooxoglutarate,onemoleculeofNADHandonemoleculeofCO2areformed.

5.A–CancellousCancellousbone(alsoknownasspongyortrabecularbone)iswherebonemarrowtissuecanbefound.Compact(orcortical)boneistheharderouterlayerofbone.Theterms‘woven’and‘lamellar’refertothe way the bone is microscopically deposited: woven bone is disorganized and weaker, and it isgraduallyremodelledintothestrongerandmoreorganizedlamellartype.

6.B–IsocitrateIsocitrateisanothersix-carboncompoundfoundintheKrebscycle.

7.C–Mureceptor

Opioidsarechemicals thatbindtoopioidreceptors.Thereare threemainopioidreceptors,μ,κandδ(mu,kappaanddelta),althoughupto17havebeendescribed.Theyworkprincipallyontheμreceptor,whichwassonamedafteritwasfoundtoberesponsibleformorphine’saction.Therearethreesubtypesofμ-receptor:μ1,μ2andμ3.μ1receptorsareassociatedwithanalgesia;μ2receptoractivationresultsinrespiratory depression and euphoria; and μ3 receptors may result in vasodilation. Another importantreceptoristheopioid-receptor-likereceptor1(ORL1),whichisinvolvedinpainresponsesandplaysaroleinthedevelopmentoftolerancetoμ-opioidagonistsusedasanalgesics.AlltheopioidreceptorsareG-protein-coupled receptors that affect GABA neurotransmission. Common side-effects of opioidsinclude nausea, vomiting, drowsiness, itching, dry mouth, respiratory depression, miosis (papillaryconstriction),dependence,tolerance,constipationandhallucinations.

Mostadverseeffectscanbemanagedasfollows:

Nauseaandvomiting–antiemeticssuchasmetoclopramideorthe5-HT3antagonistondansetron

Drowsiness–CNSstimulantssuchascaffeine

Itching–antihistamines

Respiratorydepression–respiratorystimulants,e.g.doxapram

Constipation–laxatives

Allopioideffectscanbereversedusinganopioidantagonistsuchasnaloxone

8.C–PatellaAsesamoidboneisabonewhichdevelopswithinatendonormuscle.Thelargestexampleisthepatella,which is foundwithin thequadriceps tendon.Sesamoidbonesareused tomodifypressure, todiminishfriction,andoccasionallytoalterthedirectionofamusclepull.

9.C–Succinyl-CoAsynthetaseSuccinyl-CoA is metabolized by the enzyme succinyl-CoA synthetase to form succinate. During thisprocess,amoleculeofbothguanosinetriphosphateandHSCoAisformed.Theseareremovedfromthecycle.

10.E–AntispasmodicNSAIDs inhibit cyclooxygenase (COX)enzymes.Theyare analgesics, anti-inflammatories, antipyreticsandantiplatelets.Theydonotrelievebowelspasm.

11.E–RofecoxibRofecoxibisaselectiveinhibitoroftheisoenzymecyclooxygenaseCOX-2.Itisthereforethoughtnottohavegastrointestinalside-effects,whichoccursecondarytoCOX-1inhibition.However,long-termuseofselective COX-2 inhibitors has been associated with an increased risk of cardiovascular thromboticevents,andthesehavethereforebeenwithdrawn.Itshouldbenotedthatnon-selectiveNSAIDshavealsobeenassociatedwithasmallincreaseintheriskofthromboticevents,andthusthelowesteffectivedoseshouldalwaysbeprescribedfortheshortestperiodoftimepossible.

12.C–Jejunum

Thevilliwithin the jejunumaremuch longer than those in theduodenumor ileum.They increase theirareafurtherwiththepresenceofmicrovilliandconsequentlyincreasetheirnutrientabsorption.Theyalsohave large circular folds within the submucosa which allow for an increase in the surface area. Incomparisontomoreproximalpartsofthesmallintestine,theilealvilliarefarshorter.ThisisduetoitsmainfunctionofvitaminB12andbilesaltabsorption,solessabsorptivecapacityisrequired.

13.E–GTPandHSCoADuring the conversion of succinyl-CoA to succinate, a molecule of guanosine triphosphate (GTP) isformed,aswellasamoleculeofHSCoA.Theseareremovedfromthecycle.

14.D–KoilonychiaisarecognizedfeatureBlood loss is the dominant cause of iron deficiency in theWesternworld. Laboratory findingswouldshowhypochromic,microcyticcells.Circulatingserumferritinandironarereduced,alongsideincreasedtransferrinlevelsandunsaturatedironbindingcapacity.Ironisprimarilyabsorbedthroughtheduodenum.Characteristic (although relativelyuncommon) featuresof irondeficiency includekoilonychias (spoon-shapednails),glossitis,pica(anappetitefornon-nutritivesubstances)andhairthinning.

15.B–Thenormalplateletcountrangeforallagesis150–250×109/LThereferencerangeforplateletlevelsinmosthospitallaboratoriesisbetween150and400×109/L.Thisreferencerangeisapplicableforallages.

16.E–ItliesposteriortotheoesophagusTheleftmainbronchusgivesoffanupperandalowerlobebranchafterenteringthehilum.Theleftmainbronchusliesanteriortoboththeoesophagusanddescendingaorta.Thepulmonaryarteryliesabovetheleftmainbronchus.

17.E–Theliverandthekidneysarethechiefsitesofhaematopoiesisfrom6weeksto7months’gestationHaematopoiesis (fromtheGreekhaema=blood;poiein= tomake) is the formationofbloodcellularcomponents.Indevelopingembryosbloodformationoccursinaggregatesofbloodcellsintheyolksac.Asdevelopmentprogressesfrom6weeks,bloodformationoccursinthespleen,liverandlymphnodes.Insomevertebrateshaematopoiesisoccurswhereverthereisaloosestromaofconnectivetissue,suchasinthekidneyorgut.

18.C–CysticmedialdegenerationAbdominalaneurysmaldiseaseisacommonandoccasionallyfatalcondition.Itisdefinedasadilatationof theaortaofgreater than50%of itsoriginaldiameter.Generally, it isadiseaseofoldage. It is sixtimesmorecommoninmenthanwomen.Thestrongestaetiologicalfactoristhoughttobeatherosclerosis,but there is also a strong familial component. Diabetes is thought to be protective. Cystic medialdegeneration describes the loss of muscle and elastic fibres in the aortic media, and it is stronglyassociatedwithatherosclerosisandhypertension.TheUKSmallAneurysmTrialhasdemonstrated thataneurysmscanbesafelymonitoreduntiltheyreach5.5cmindiametersize,becomesymptomaticorgrowbymorethan1cm/year.

19.A–BloodentersthespleenviathesplenicarteryThespleenisthelargestlymphoidorganandissituatedinthelefthypochondrium.Thereisanincreasedriskofoverwhelminginfectionsinpatientsaftersplenectomy.Splenectomyisperformedmostfrequently

followingtraumaticinjury.

20.E–ParacetamolA patient with migraine should initially be treated with a simple analgesic, such as paracetamol.Morphine and codeine can exacerbate the nausea associatedwithmigraine. Fentanyl is not indicated.Methysergideisusedasmigraineprophylaxisbutisnoteffectiveintheacutesetting.

21.D–StaphylococcusaureusInertmaterialssuchascrystalsorsyntheticfibresareunable tobeeradicated,andso triggerachronicinflammatoryresponse.Virusesandcertainbacteria(includingMycoplasmatuberculosis)alsodo this.Most staphylococcal infections will initiate an acute inflammatory response only. Giant macrophagesformwhenmultiplemacrophagecellmembranesfuseas theycollectively try toengulfamaterial.Thishappenswhen they are facedwith indigestibleminerals (e.g. silica), or bacteriawith indigestible cellwalls(M.tuberculosis).

22.D–TheformationofcellulardebriscomposedoflivinganddeadneutrophilsandbacteriaSuppuration is the formation of cellular debris composed of living and dead neutrophils, bacteria andcellular debris (pus). The accumulation of puswithin amembrane is called an abscess, andwithin ahollowviscus isanempyema.Afistula isanabnormalcommunicationbetweentwoepithelialsurfaces(apartfromarteriovenousfistulae,whichoccurbetweentwoendothelialsurfaces),andasinusisablindendingtractcommunicatingwithanepithelialsurface.

23.B–TheABOsysteminvolvesnaturallyoccurringIgManti-Aandanti-BantibodiesTheABO blood group involved naturally occurring IgM antibodies,while rhesus (Rh) antibodies areusuallyIgG.TheABOandRhsystemsare thetwomajorbloodgroupsystems,althoughtheKell,DufyandKiddgroupsystemsarethenextmostclinicallysignificant.Antigensonthesurfaceofredcellsonlydeterminethebloodgroups.

24.A–BradycardiaBradycardiaisnotadocumentedside-effectofparacetamoluse.Rashes,blooddisordersandhypotension(whengivenintravenously)arerareside-effectsofparacetamol.

25.A–BonemarrowfailureBonemarrowfailureincludesagroupofdisordersthatcanbeeitherinheritedoracquired.Itcanleadtoanacutelyorchronicallyimpairedproductionofallorsomeofthebloodcellularcomponents.

26.D–β-CateninTheAPCgenemarksβ-cateninfordegradationbyubiquitination.AdeletionintheAPCgenecausesanincreaseinthecytoplasmiclevelsofβ-catenin,whichinturnleadstoanincreaseinthenuclearlevelsofβ-catenin,andthisresultsinanincreasedtranscriptionofgenesassociatedwithcellularproliferation.

27.C–HaemophiliaAisinheritedasanX-linkeddisorderHaemophilia A (factor VIII deficiency) and haemophilia B (factor IX deficiency) are inheritedcoagulation disorders. Haemophilia A and B are inherited as an X-linked recessive disorder.HaemophiliaBisalsoknownasChristmasdisease.HaemophiliaAisassociatedwithanormalbleedingtime.

28.A–Pelvis

The appendicular skeleton describes the part of the skeleton that supports the limbs. It comprises thebonesofthepectoralgirdle,thepelvisandtheupperandlowerlimbs.Theaxialskeletoncomprisesthebones of the skull, vertebral column, ribs and sternum.This is just onewayof organizing the skeletalsystem.

29.E–NoneoftheaboveSharpeyfibresarecomposedofamatrixofconnectivetissuewhichconnectstheperiosteumtothebone.Remakbundlesare theeponymousnameforgroupsofC-fibreaxons.Schwanncellsarea typeofglialcell which cover an axon, andMerkel cells are found in the skin and are part of the somatosensorysystem.

30.B–MuscularisexternaAuerbach’splexusispartoftheentericnervoussystem.Itisfoundbetweenthelongitudinalandcircularlayers of the muscularis externa. It provides both sympathetic and parasympathetic input to thegastrointestinaltract.

31.E–ItisstrongduetoitslamellarstructureThe mechanical properties of bone depend largely on its unique integrated lamellar structure.HydroxyapatiteistheprimarymineralfoundinboneandthecollagenisoftypeI.

32.A–Co-codamolCo-codamol is a combination of codeine and paracetamol. Co-dydramol contains dihydrocodeine andparacetamol.Co-proxamolcontainsparacetamol anddextropropoxyphene.Neither co-tramadolnor co-proxafolexist.

33.D–AlloftheaboveOsteoidosteomasarebenignneoplasiaswhichcanarisefromanyoftheperiosteum,cortexormedullarycavity.Cortical tumoursare themostcommon,accountingforup to80%ofallosteoidosteomas.Theypresentwithfocalbonepain,whichisoftenworseatnight.Bonescanswillshowincreasedactivityatthetumoursite.Theyoftenregressspontaneously.

34.E–TrabeculaeTrabeculaearethespiculesseenonspongybones.Theyarethelattice-shapednetworkwhichformsthetissue. Canaliculi are themicroscopic canals within the bone. An osteocyte rests in a space called alacuna,whichissituatedbetweenlamellae.Sharpeyfibresarecollagenfibresthatextendintoaboneatan angle. Tomes processes are extensions of odontoblast cells in the teeth that are involved in theproductionofenamel.

35.D–MorphineOpioidsareassociatedwithdependenceandbothpsychologicalandphysiologicalwithdrawalsymptoms.Symptomsofopiatewithdrawalincludeagitation,anxiety,muscleachesandsweating.Buprenorphine,apartialopioidreceptoragonist,isausefultreatmentofchoice.

36.A–EpiduralAnepidural is themost appropriatemeans of analgesia in this case, and this can be combinedwith apatient-controlled analgesia (PCA) system. It provides adequate pain relief in the immediate stagespostoperatively.Overtheensuingdays,itcanbeweanedandreplacedbyintravenousanalgesia.

37.C–TypeIcollagenType I collagen is the organic component of bone,whereas hydroxyapatite and calciumphosphate areinorganiccomponents.Theseorganicandinorganiccomponentsproducethematrixofthelongbone.TypeIcollagenisalsopresentinscartissue,tendonsandtheendomysiumofmyofibrils.

38.D–TheyrunperpendiculartoHaversiancanalsVolkmanncanals–alsoknownasperforatingcanals–are found incompact (cancellous)boneandrunperpendiculartoHaversiancanals,connectingthemwitheachother.Thecanalsalsocarrysmallarterieswhichrunthroughoutthebone.

39.B–MetoprololThecardioselectivebeta-blockersareatenolol,bisoprolol,metoprolol,nebivololandacebutolol.Theseagentshavealessereffectonairwayresistancecomparedtounselectivebetaantagonists.Underextremecaution and supervision, these drugs may be used in patients with a history of asthma orbronchoconstriction if there isnoalternative (although this is a consultantdecision).There isnoclearlong-termcardiovascularbenefitofbeta-blockersinuncomplicatedhypertension.

40.D–LiverfailureAnimportantbut relativecontraindication to theuseofparacetamol is liver failure.Gastriculceration,asthma and uncontrolled bleeding are contraindications to the use of non-steroidal anti-inflammatorydrugs(NSAIDs).

41.C–BisoprololBeta-blockerscanhaveanadverseeffectofimpotence.Itisextremelyimportanttowarnpatientsaboutthisbeforestartingthemonthisclassofdrugs,astheymaybetooembarrassedtopresenttotheirGPandendup livingwith aproblem that is easily reversible.Beta-blockers can also causenightmares, vividdreams,hallucinations,poorefforttoleranceandlowmood,amongmanyotherside-effects.

42.E–ResettingofthehypothalamicthermostatbyendogenouschemicalsEndogenouschemicalscausingpyrexiaarecalledpyrogens.Theirreleaseisstimulatedbyphagocytosisand by the presence of immune complexes and endotoxins (e.g. lipopolysaccharide). Examples ofpyrogensincludeIL-2andTNF.Theirreleaseresultsinincreasedlevelsofcyclooxygenaseandthereforeprostaglandin production. In the hypothalamus, prostaglandins, especially prostaglandin E2 (PGE2),stimulate neurotransmitterswhich reset the hypothalamic thermostat to a higher level.ACTH, pituitaryhormonesandthesympatheticsystemarenotinvolved.

43.C–25timesincreasePeoplewhohavethep53mutationintheirgermlinehavea25timesincreasedriskofdevelopingcancer.Thep53gene isa tumoursuppressorgeneand is responsible foractivatingDNArepair in response tocell damage, inducing arrest of growth by halting the cell cycle at the G1/S phase and allowing anydefectsinDNAtoberepairedatthisstage,andinactivatingapoptosisinresponsetoirreparableDNAdamage.

44.E–SepticshockSeptic shock, like anaphylactic shock, is a form of distributive shock. Here, a systemic inflammatoryreactiontoaninvadingpathogenleadstoaprofoundlossofvasculartoneandahugeincreaseincapillarypermeability.Subsequentlythereisinsufficientperipheralresistanceandcardiacpreloadtomaintainanadequatebloodpressure.

45.D–InfiltrationofneutrophilsNeutrophils predominatewithin the acute phase of inflammation.Later,macrophages, lymphocytes andplasmacellspredominate.GranulomasforminthepresenceofpersistentT-cellactivation,orinresponsetoforeignmaterialthatcannotbedigested.Inbothcases,theinvadingorganismorsubstanceisencircledbyawallofmacrophagesandlymphocytes(withorwithoutfibroblastsandconnectivetissue).Fibrosisis the resultof scar formationandcollagendepositionand the tissue involveddoesnot fully regain itsstructureorformerfunction.InterferongammahasantiviralactionsandisproducedbyactivatedT-cells.

46.B–IleumPeyer’s patches are organized lymphoid tissues which are nearly all found in the ileum in the smallintestine.They appear to beoval or round in shape and arepresent in the laminapropria layer of themucosa.

47.A–ComplementAll the mediators given, apart from complement, are derived from cells within the location ofinflammation. Nitric oxide is produced by endothelial cells, and prostaglandins by mast cells andleukocytes.Serotoninisapreformedmediatorthatisstoredwithinplateletsecretorygranules,andTNFis produced by various cells including macrophages, endothelial cells and lymphocytes. Complementcomponents are synthesized by the liver and travel to sites of inflammationwhereupon they rely uponlocalactivation.

48.D–ItisrelatedanteriorlytothesuperiorvenacavaTheazygousveingoesover therightmainbronchus into thesuperiorvenacava(SVC).TherightmainbronchusliesposteriortotheSVCandascendingaorta.Therightmainbronchusdescendsmoreverticallythan the left. Itgivesoff threebranches,oneforeach lobeof theright lung(upper,middleand inferiorlobebranches).Therightmainbronchusgivesoffthebranchfortheupperlobebeforeenteringthehilum.

49.A–AdjacentsegmentsarecommunicatingEachlunghas10wedge-shapedsegmentsandeachsegmentisadiscretelyfunctioningunitwithitsownneurovascular supply. There is no communication between the segments. As a result of the clearanatomical separation of these bronchopulmonary segments, a segment can be removed withoutinfluencingthefunctionofneighbouringsegments.

50.D–AlloftheaboveThe mucosa throughout the small intestine is lined with simple columnar epithelium. These cells areprimarily enterocytes. They are often coatedwith a glycocalyxwhich contains digestive enzymes. Ontheir apical surface there will be villi to increase the surface area. They are also able to secreteimmunoglobulins.

QuestionsPaper71.Whichofthefollowingbenzodiazepineshastheshortestdurationofaction?

A. Diazepam

B. Lorazepam

C. Midazolam

D. Nitrazepam

E. Temazepam

2.WithinwhichlayeristheMeissner’splexusfound?

A. Laminapropria

B. Muscularisexterna

C. Muscularismucosa

D. Serosa

E. Submucosa

3.Which of the following statements best describes the action of parathyroid hormone (PTH) on thekidney?

A. PTHdecreasescalciumreabsorptioninthethickascendinglimboftheLoopofHenle.

B. PTHincreasescalciumreabsorptionatthedistaltubule.

C. PTHincreasesglomerularfiltrationrate.

D. PTHincreasessecretionofcalciumbytherenaltubules.

E. PTHincreasesurinaryexcretionofcalcium.

4.During periods of starvation,muscle proteins are broken down to supply the bodywith an energysource.Whichoneofthefollowingstatementsregardingthisbiochemicalpathwayiscorrect?

A. Gluconeogenesisiscatalysedbyglucagonintheliver.

B. Musclebreakdownprovidestheliverwithglycogenfromwhichtoformglucose.

C. Musclebreakdownresultsinthereleaseofglucosedirectlyintothebloodstream.

D. Musclebreakdownsuppliestheliverwithpyruvateforgluconeogenesis.

E. The liver converts fatty acids into glucose in response to muscle breakdown during periods ofstarvation.

5.Whichoneofthefollowingstatementsistrueregardingsympatheticinnervationtotheheart?

A. Decreasestherateandforceofcontraction

B. Increasestheforceofcontractionanddecreasestheheartrate

C. Increasestheheartrateanddecreasestheforceofcontraction

D. Increasestherateandforceofcontraction

E. Noneoftheabove

6.Whichofthefollowingreceptors,whenboundtoanappropriateligand,wouldnotinduceactivationofaphagocyte?

A. CD4receptor

B. Clqreceptor

C. CR1receptor

D. Fcreceptor

E. Toll-likereceptor

7.Whichoneofthefollowingisthesecondmessengersysteminvolvedinincreasingheartrateandforceofcontraction?

A. Calcium

B. Cyclicadenosinemonophosphate

C. Cyclicguanosinemonophosphate

D. Inositoltrisphosphate

E. Nitricoxide

8. Which of the following is a life-threatening type of cellulitis which occurs in the submandibularspace?

A. Boerhaavesyndrome

B. Caplansyndrome

C. Ludwigangina

D. Ondinecurse

E. Prinzmetalangina

9.Acetylcholineslowstheheartbyactingonwhichoneofthefollowingreceptors?

A. Adrenergicreceptors

B. GABAreceptors

C. Glutamatereceptors

D. Muscarinicreceptors

E. Noneoftheabove

10.Whichofthestatementsbelowregardingtheerythrocytesedimentationrate(ESR)ismostlikelytobecorrect?

A. AlowESRoccursininfection.

B. AlowESRoccursinmalignancy.

C. ESRislargelydeterminedbyplasmaconcentrationsofwhitebloodcellsinthebody.

D. ESRmeasurestherateoffallofacolumnofsuspendedredcellsin24hours.

E. ThenormalrangeofESRriseswithincreasingage.

11. Acetylcholine decreases the force of contraction of the heart by decreasing which one of thefollowing?

A. Calcium

B. Cyclicguanosinemonophosphate

C. Inositoltrisphosphate

D. Intracellularcyclicadenosinemonophosphate

E. Nitricoxide

12.Whichofthefollowingismostlikelytobeseeninacuteepiglottitis?

A. Cervicaladenopathy

B. Tenderlarynx

C. Tonsillarenlargement

D. Tonsillarexudate

E. Trismus

13. Activation of the parasympathetic postganglionic neurons innervating the bladder wall results inwhichofthefollowing?

A. Contractsandrelaxesthesmoothmuscle

B. Contractsthesmoothmuscle

C. Relaxesthesmoothmuscle

D. Both(A)and(B)

E. Noneoftheabove

14.Inrelationtothebladder,postganglionicfibresfromsympatheticneuronspassviawhichnerve?

A. Commonperonealnerve

B. Genitalbranchofthegenitofemoralnerve

C. Hypogastricnerve

D. Ilioinguinalnerve

E. Sciaticnerve

15.Erectiletissueiscontrolledbywhichofthefollowing?

A. Bothparasympatheticandsympatheticsystems

B. Parasympatheticsystemandthereleaseofacetylcholine

C. Parasympatheticsystemandthereleaseofnitricoxide

D. Sympatheticsystemandthereleaseofadrenaline

E. Sympatheticsystemandthereleaseofnitricoxide

16.Whichoneofthefollowingbestdescribesthecorrectstructureoftheplatelet?

A. Aspirinpromotestheformationofnewplatelets.

B. Plateletsareanucleate.

C. Plateletsarecellsandthereforecontainnuclei.

D. Plateletssurviveforlongerthan120days.

E. Theirbiconcaveshapeenhancesoxygendeliveryatthecellularlevel.

17.Whichoneofthefollowingconditionsandmodesofinheritancematchcorrectly?

A. HaemophiliaA:autosomalrecessive

B. HaemophiliaB:autosomalrecessive

C. Hereditaryspherocytosis:autosomaldominant

D. Sicklecelldisease:autosomaldominant

E. Thalassaemia:sex-linked

18.A29-year-oldwomanpresents toherGPwithweight lossandpalpitations.Examination revealsadiffusesmoothneckswelling.Whichoneofthefollowingmedicationsshouldbecommenced?

A. Carbimazole

B. Digoxin

C. Hydrocortisone

D. Levothyroxine

E. Liothyronine

19.Benzodiazepinesactthroughwhichofthefollowingmechanisms?

A. 5-HTreceptoragonism

B. Betaadrenoceptorantagonism

C. GABAreceptoragonism

D. Serotoninagonism

E. Noneoftheabove

20.Theaxonfrompreganglionicneuronsoftheautonomicnervoussystemis:

A. Myelinatedanditscellbodyisfoundintheautonomicganglion

B. Myelinatedanditscellbodyisfoundinthecentralnervoussystem

C. Myelinatedanditscellbodyisfoundintheperipheralnervoussystem

D. Unmyelinatedanditscellbodyisfoundinthecentralnervoussystem

E. Unmyelinatedanditscellbodyisfoundintheperipheralnervoussystem

21. A woman is due to have an elective subtotal thyroidectomy. Carbimazole was stopped 14 dayspreviously.Whichoneofthefollowingmedicationsshouldbecommencedpreoperatively?

A. Levothyroxine

B. Liothyronine

C. Potassiumiodide

D. Propranolol

E. Propylthiouracil

22.A32-year-oldmanpresentstotheemergencydepartmentwitha1-weekhistoryoflethargyandfever.Examination reveals a pulse rate of 96 beats/minute and a mildly enlarged thyroid gland withtenderness to palpation. Thyroid function tests show mild hyperthyroidism and there was a lowthyroiduptakeonscintiscan.Whatistheidealtreatmentinthisscenario?

A. Carbimazole

B. Ibuprofen

C. Levothyroxine

D. Liothyronine

E. Propranolol

23.Whichoneofthefollowingistrueabouttetracyclines?

A. Theyareassociatedwithveryfewside-effects.

B. Theyarebactericidal.

C. Theyarebacteriostatic.

D. TheyinhibitDNAgyrase.

E. Theyinhibittranspeptidation.

24.Whichofthefollowingisthemainactivemetaboliteofdiazepam?

A. Desmethylflurazepam

B. Nordazepam

C. Triazolam

D. Zolpidem

E. Noneoftheabove

25.Whatisthedangerofselectivecyclooxygenase2enzymeinhibition?

A. Increasedriskofgastriculceration.

B. InhibitionofprostacyclinproductionisgreaterthaninhibitionofthromboxaneA2production.

C. InhibitionofthromboxaneA2productionisgreaterthanprostacyclinproduction.

D. Leukotrieneproductionisuninhibited.

E. Negligibledanger.

26.Three days post-total thyroidectomy, a patient exhibits symptoms of numbness around her lips andtinglinginherfingers.ExaminationrevealsapositiveChvosteksign.Treatmentwithwhichoneofthefollowingshouldbecommenced?

A. Calciumgluconate

B. Carbimazole

C. Levothyroxine

D. Pamidronate

E. Notreatmentrequired

27.Whichoneofthefollowingisanantagonistofhistamineandnoradrenalinereceptors?

A. Clozapine

B. Olanzapine

C. Quetiapine

D. Risperidone

E. Sertindole

28.Theparasympatheticsystemformspartofwhichofthefollowing?

A. Autonomicnervoussystem

B. Centralnervoussystem

C. Peripheralnervoussystem

D. Alloftheabove

E. Noneoftheabove

29.Theautonomicnervoussystemmotorpathwaystypicallyconsistofhowmanyneurones?

A. One

B. Two

C. Three

D. Four

E. Six

30.Theaxonfrompostganglionicneuronsoftheautonomicnervoussystemis:

A. Myelinatedanditscellbodyisfoundintheautonomicganglion

B. Myelinatedanditscellbodyisfoundinthecentralnervoussystem

C. Unmyelinatedanditscellbodyisfoundintheautonomicganglion

D. Unmyelinatedanditscellbodyisfoundinthecentralnervoussystem

E. Unmyelinatedanditscellbodyisfoundintheperipheralnervoussystem

31.Whichoneofthefollowingdrugsisassociatedwithariskofagranulocytosis?

A. Clozapine

B. Haloperidol

C. Olanzapine

D. Quetiapine

E. Risperidone

32.Inchemotaxis,thebindingofchemotaxinstoleukocyteG-proteincellreceptorscausesanincreaseinwhichofthefollowing?

A. Adenosinetriphosphate(ATP)andbasalmetabolicactivity

B. Cytosoliccalciumandcontractionofmicrotubules

C. Cytosoliccalciumandgrowthofpseudopods

D. FormationofmRNAandgrowthofflagella

E. Formationofnucleicacidsandenlargementofcellnucleus

33.WhichoneofthefollowingisaD2/D3receptorantagonist?

A. Amisulpride

B. Clozapine

C. Olanzapine

D. Quetiapine

E. Risperidone

34.Preganglionicneuronsoftheparasympatheticdivisionaresituatedinfourcranialnervenucleiinthebrainstem.Theseare:

A. Glossopharyngeal,vagus,opticandabducens

B. Oculomotor,facial,glossopharyngealandvagus

C. Oculomotor,vagus,trochlearandtrigeminal

D. Olfactory,hypoglossal,accessoryandvagus

E. Opticnerve,oculomotor,trigeminalandfacialnerve

35. Adhesion of leukocytes to endothelial cells is mediated by which type of receptor expressed onleukocytecellsurfaces?

A. E-selectin

B. Integrins

C. Intercellularadhesionmolecule1

D. L-selectin

E. P-selectin

36.Oncewithintheinterstitium,leukocytesmigratetowardsthesiteofinjurybychemotaxis.Whichofthefollowingmoleculeswouldnotinduceleukocytechemotaxis?

A. C5a

B. Chemokines

C. IgG

D. LeukotrieneB4

E. Plateletactivatingfactor

37. In the parasympathetic system, preganglionic neurons originating from nuclei of cranial nerve IIIsynapsewhere?

A. Ciliaryganglion

B. Coeliacganglion

C. Inferiormesentericganglion

D. Submandibularganglion

E. Superiormesentericganglion

38.Whichoneofthefollowingstatementsconcerninglungdevelopmentisincorrect?

A. Atrachealbudformsfromtheforegut.

B. Alveolardevelopmentcontinuesuntil2yearsofage.

C. At16weeks’gestation,bronchialbranchingiscomplete.

D. Differenttissueswithinthelungdevelopatdifferentrates.

E. Malformationofthelungisdependentonthetimingoftheinsultratherthanthenatureoftheinsult.

39.Whichoneofthefollowingdefinitionsbestdescribesphagocytosis?

A. Cellulardeathinitiatedfromwithinthecellitself

B. Excretionofsubstanceswithincellvesiclesbyfusionwiththecellmembrane

C. Regrowthofbloodvesselsfollowinginjury

D. Theengulfmentanddigestionofsolidparticlesbycells

E. Theintakeoffluidintoacellbyengulfment

40.Whichoneofthefollowingstatementsaboutalveoliisincorrect?

A. Alveoliaccountforthegreatestproportionoflungvolume.

B. Gasexchangeoccursthroughthealveolarbasementmembrane.

C. TypeIalveolarcellsarethickcellsprovidingstructuralintegritytothesurfacelining.

D. TypeIalveolarcellsmakeup90%ofthealveolarsurfacelining.

E. TypeIIalveolarcellsproducesurfactant.

41. In the parasympathetic system, preganglionic neurons originating from cranial nerve VII nucleisynapsewhere?

A. Ciliaryganglion

B. Coeliacganglion

C. Oticganglion

D. Pterygopalatineganglion

E. Superiorcervicalganglion

42.Stimulationofsecretionof the lacrimalandsalivaryglands ismediatedviawhichof thefollowingcranialnerves?

A. CranialnerveII

B. CranialnervesVII/IX

C. CranialnerveX

D. CranialnerveXI

E. CranialnerveXII

43.Whichoneofthefollowingisnotacommonsymptomofacuteepiglottitis?

A. Cough

B. Drooling

C. Dysphagia

D. Fever

E. Stridor

44.Intheuppergastrointestinaltract,parasympatheticinnervation:

A. Decreasessecretions,peristalsisandcontractionofsphincters

B. Decreasessecretions,peristalsisandrelaxationofsphincters

C. Increasessecretions,decreasesperistalsisandrelaxationofsphincters

D. Increasessecretions,peristalsisandcontractionofsphincter

E. Increasessecretions,peristalsisandrelaxationofsphincter

45.Whicheicosanoidstimulateschemotaxisofneutrophils?

A. LeukotrieneB4

B. LeukotrieneC4

C. ProstacyclinPGI2

D. ProstaglandinPGE2

E. ThromboxaneA2

46.Apatientsufferingwithaquinsymayhavewhatpathognomonicsymptom?

A. Barkingvoice

B. Hotpotatovoice

C. Quackcough

D. Rosespots

E. Noneoftheabove

47.Whicheicosanoidincreasesthesensitivityofpainreceptorsandcanaidtheproductionoffever?

A. LeukotrieneB4

B. LeukotrieneC4

C. ProstacyclinPGI2

D. ProstaglandinPGE2

E. ThromboxaneA2

48. Why does regular ingestion of aspirin or ibuprofen result in an increased risk of gastric ulcerformation?

A. Inhibitionofcyclooxygenase1(COX-1)

B. Inhibitionoflipoxygenase

C. InhibitionofphospholipaseA2

D. Selectiveinhibitionofcyclooxygenase2(COX-2)

E. Stimulationofhydrogenionrelease

49.Duringperistalsis,theactivationofentericneuronsoccursviawhichoneofthefollowingreceptors?

A. Adrenergicreceptors

B. GABAreceptors

C. Glutamatereceptors

D. Muscarinicreceptors

E. Nicotinicreceptors

50.Select the option below that correctly displays the order of events bywhichneutrophils locate anactiveareaofinflammation

A. Adhesion of integrins to endothelium, margination and rolling, diapedesis and phagocytosis ofmicrobials

B. Chemotaxistowardssiteofinjury,marginationandrolling,adhesionofintegrinstoendotheliumanddiapedesis

C. Chemotaxis towards site of injury,margination and rolling, adhesion of integrins to endothelium,phagocytosisofmicrobials

D. Diapedesis,adhesionofintegrinstoendothelium,marginationandrolling,chemotaxistowardssiteofinjury

E. Marginationandrolling,adhesionofintegrinstoendothelium,diapedesis,chemotaxistowardssiteofinjury

AnswersPaper71.C–MidazolamMidazolam isanultra-short-actingbenzodiazepinewithahalf-lifeof2hoursanddurationofactionoflessthan6hours,makingitanidealpremedicationforsurgery.Thisiscomparedtodiazepamwhichhasalongdurationofaction,upto100hours,becausediazepamfirstmetabolizestothemetabolicallyactivedesmethyldiazepam,oxazepamandtemazepam.

2.C–MuscularismucosaMeissner’splexus(submucosalplexus)innervatesthesmallintestinewithparasympatheticfibresandisfound in the muscularis mucosa. The nerve bundles within the submucosal plexus innervate the cellswithintheepitheliallayerandthesmoothmuscleofthemuscularismucosa.

3.B–PTHincreasescalciumreabsorptionatthedistaltubuleParathyroid hormone (PTH) is released by the parathyroid glands in response to low extracellularcalcium. Inorder tonormalizeplasmacalcium,PTHactsonbone to increaseosteoclasticactivityandbone demineralization,which results in the release of calcium. PTH also stimulates the conversion ofvitamin D to its active form, 1,25-dihydroxycholecalciferol, which increases intestinal absorption ofcalcium.Finally,PTHincreasesthereabsorptionoffilteredcalciumatboththethickascendinglimboftheLoopofHenleandthedistaltubule,thusconservingcalciumbyreducingitsurinaryexcretion.

4.D–MusclebreakdownsuppliestheliverwithpyruvateforgluconeogenesisDuring periods of starvation, muscle proteins can be utilized for gluconeogenesis. By definition,gluconeogenesis is the formation of glucose from non-carbohydrate precursors. Amino acids (mainlyalanine)frommuscleproteinsprovidethesourceofpyruvateforgluconeogenesisintheliver:2Pyruvate+2NADH+4ATP+2GTP+4H2O→Glucose+2NAD++4ADP+2GDP+2H++6

PiAlcohol reduces the ability of the liver to perform gluconeogenesis. Ethanol creates high levels ofNADH,which promotes the formation of lactate from pyruvate, thus reducing the amount of pyruvateavailableforgluconeogenesis.

5.D–IncreasestherateandforceofcontractionThe sympathetic division of the autonomic nervous system exhibits a flight-or-fight response, thusincreasingboththeheartrateandtheforceofcontraction.

6.A–CD4receptorToll-likereceptors(TLRs)areafamilyofpatternrecognitionreceptorswithinmacrophages,mastcellsand dendritic cells. TLRs detect the presence of invading microorganisms by identifying commonmolecules within their membranes. Lipopolysaccharide, for example, is the main ligand for TLR-4.Bindingofaligandinducesaninflammatoryandinnateimmuneresponse.TheFcreceptor(contained,forexample, within macrophage and neutrophil membranes) binds specifically to the Fc region of anantibody. TheClq receptor recognizes the first component of the complement pathway.CR1 receptors

bind toC3b.Both antibodies and complement components act as opsonins to induce phagocytosis andsuperoxideproduction.CD4isaco-receptorforMHCclassIImolecules,expressedbyT-lymphocytesduringrecognitionofaforeignantigen.

7.B–CyclicadenosinemonophosphateThesignallingconductionpathwayinvolvedinincreasingtherateandforceofcontractionoftheheartismediatedviathecAMP(cyclicadenosinemonophosphate)secondmessengersystem.Normally,chemicaltransmittersthatreachareceptorsituatedintheplasmamembraneactivatetransducerproteinssuchastheGprotein.This in turnactivates theprimarykeyeffectorenzymes,whichgeneratea secondmessengeractivating a secondary effector or acting directly on the target organ. The cAMP secondmessenger isproducedbyadenylylcyclasefollowingitsactivationbyaGprotein,whiletheprimaryeffectorenzymethatactivatestheinositolpolyphosphatepathwayisproteinkinaseC.

8.C–LudwiganginaLudwig angina is a rare but life-threatening infectionmost often caused byStreptococcus. The word‘angina’isderivedfromtheGreekankhone=strangling.Ludwiganginaisaninfectionofthetissuesinthefloorofthemouth,oftenwithconcomitantdentalinfection.

9.D–MuscarinicreceptorsMuscarinic receptors are present in the cardiocytes of the sinoatrial and atrioventricular nodes of theheart.TheeffectofacetylcholineonthemuscarinicreceptorsofthesenodesistoincreasetherestingK+

conductance,resultinginadecreaseinheartrate.

10.E–ThenormalrangeofESRriseswithincreasingageESRmeasurestherateoffallofacolumnofredcellsinplasmain1hour.Itislargelydeterminedbytheplasmaconcentrationsofproteins,especiallyfibrinogenandglobulins.ThenormalrangeforESRriseswithage.AraisedESRoccursininflammatorydisorders,infections,malignancy,myeloma,anaemiaandpregnancy.

11.D–IntracellularcyclicadenosinemonophosphateThe release of acetylcholine from parasympathetic nerve terminals, which then acts on muscarinicreceptorsinthecardiocytesofthecardiacmuscle,leadstoanincreaseintherestingK+conductance inthesecells.ThisriseinK+conductancehyperpolarizesthecell,thereforereducingtherateofcontraction.ThedecreaseinforceofcontractionismediatedbydownregulatingintracellularcAMPandsubsequentlyreducingtheL-typeCa2+channelsthatareresponsibleforexcitation–contraction.

12.B–TenderlarynxAcuteepiglottitisistheresultoflocalizedHaemophilusinfluenzaeinfectionofthesupraglotticlarynx.Itisamedicalemergencyastheinflamedepiglottiscancausecompleteairwayobstruction.Donotlaythepatientdown;keepthemuprightandascalmaspossible.ImmediateassessmentbyENTandanaestheticsisrequired.NotethatfollowingtheintroductionoftheHib(HaemophilusinfluenzatypeB)vaccinetheincidenceofepiglottitishasreduced.

13.B–ContractsthesmoothmuscleParasympathetic innervationcausescontractionandencouragesemptyingof thebladder.Postganglionicneuronsinthepelvicganglionmediatecontractionofthebladder’ssmoothmuscle.

14.C–Hypogastricnerve

Postganglionicfibresfromsympatheticneuronsinnervatethebladderthroughthehypogastricnerve.Whenthesympatheticsystemisactivated, theparasympatheticsystemis inhibited leading torelaxationof thebladdersmoothmuscleandcontractionoftheinternalsphincter.

15.C–ParasympatheticsystemandthereleaseofnitricoxideTheparasympatheticsystemislargelyresponsiblefortheerection.Parasympatheticinnervationleadstothe releaseofneurotransmittersand localmediators, includingnitricoxide,which relaxes thevascularsmoothmuscleinthepenis.Thereisdilationofthepenisandbloodfillsthebloodsinuses,resultinginanincrease in the size of the erectile tissues. This causes compression of the superficial veins (whichnormallydrainthepenis),leadingtoengorgementandrigidity.

16.B–PlateletsareanucleatePlateletsdonothavenuclei.Plateletsdonotsurvivelongerthan7daysandareinhibitedbyaspirin.Redbloodcellsarebiconcaveinshape,whichprovidesalargesurfaceareaforoxygentransferandthereforedeliveryatacellularlevel.

17.C–Hereditaryspherocytosis:AutosomaldominantHereditaryspherocytosisisageneticallylinkedautosomaldominantformofspherocytosis.Itisageneticdisorder of the red blood cell membrane and can cause anaemia, jaundice and splenomegaly. Bothhaemophilia A and B are sex-linked genetic disorders. Both thalassaemia and sickle cell disease areautosomalrecessivedisorders.

18.A–CarbimazoleThiswoman has hyperthyroidismmost likely due toGraves disease. This is an autoimmune conditionresulting from IgG antibodies mimicking thyroid-stimulating hormone (TSH) and binding to TSHreceptorsonthethyroidgland,thusinitiatingproductionofthyroidhormones.Thisproducessymptomsofhyperthyroidismandthereforecarbimazolewouldbethedrugofchoicetocontrolthiscondition.

19.C–GABAreceptoragonismBenzodiazepines act as GABAA receptor stimulators. Enhancing the effects of GABAA results insedation,hypnosisandanxiolysis.

20.B–MyelinatedanditscellbodyfoundinthecentralnervoussystemTheaxonofapreganglionicneuronisasmall-diameter,myelinatedtypeBfibreextendingtoautonomicganglion,andthereforetransmitsmotorimpulsesfromthecentralnervoussystemtoautonomicganglia.

21.C–PotassiumiodidePotassium iodide is used in optimizing hyperthyroid patients for surgery. This is due to its effect ofinhibiting iodination of thyroglobulin, thus reducing thyroid hormone synthesis. Eventually the thyroidgland reduces in size and vascularity and therefore it is a useful medication to give prior tothyroidectomy.

22.B–IbuprofenThispatient shows signs and symptomsofdeQuervain thyroiditis.This is normally causedby aviralinfection, producing symptoms typical of a viral illness and inflammatory changes in the thyroidglandcausing tenderness and enlargement. The inflammatory damage can occasionally result in a transientlyincreased thyroid hormone secretion. The condition is usually self-limiting but non-steroidal anti-inflammatorydrugsmaybeusedforsymptomaticrelief.

23.C–TheyarebacteriostaticTetracyclinesarebacteriostatic,whichmeanstheyacttoinhibitthegrowthofabacteriumwhichgivesthebodytimetomounttheappropriatedefence.

24.B–NordazepamNordazepam(N-desmethyldiazepam)istheactivemetaboliteofdiazepamandhasahalf-lifeof60hours.Thisleadstothelengthymetabolicactivityofdiazepam.

25.B–InhibitionofprostacyclinproductionisgreaterthaninhibitionofthromboxaneA2productionSelectiveCOX-2inhibitionisassociatedwithanincreasedproductionofthromboxaneA2(whichcausesvasoconstriction and indirect activation of platelet aggregation) out of proportion to prostacyclin (avasoconstrictor).Thisresultsinanincreasedriskofthrombosis.

26.A–CalciumgluconateHypocalcaemia is a complicationof post-thyroid surgerydue to inadvertent damageor removal of theparathyroid glands. Serum calcium levels should bemeasured, and the patient should be observed forsymptoms of hypocalcaemia in the first few days postoperatively (i.e. numbness and tingling of thehands/feet/lips, light-headedness and muscle weakness and cramps). In severe symptomatichypocalcaemia, intravenous calcium gluconate must be immediately commenced. Mild asymptomatichypocalcaemia can be treated with oral calcium and vitamin D supplementation. Chvostek sign –twitchingoffacialmusclesafterstimulationofthefacialnervebytappingoverthemassetermuscleattheangleofthejaw–isobservedinhypocalcaemia.

27.D–RisperidoneRisperidone, as well as acting as a serotonin–dopamine atypical antipsychotic, is an antagonist ofhistamine and noradrenaline receptors. It is also known to cause the highest rise in prolactin of theantipsychotics.

28.B–CentralnervoussystemThe nervous system consists of three parts: peripheral, central and autonomic.The autonomic nervoussystemconsistsofthenervecellsfoundwithinthesympatheticandparasympatheticnervoussystems.Itismainly concernedwith the innervation and regulation of visceral organs, smoothmuscle and secretoryglands.

29.B–TwoTheautonomicnervoussystemefferentneuronsdifferfromthoseofthesomaticnervoussystembecauseofthetwoneuronsbetweenthecentralnervoussystemandthetargetorgan.Thefirstneuronisreferredtoasthepreganglionicneuronandthesecondisthepostganglionicneuron.

30.C–UnmyelinatedanditscellbodyisfoundintheautonomicganglionTheaxonofapreganglionicneuronisasmall-diameter,myelinatedtypeBfibreextendingtoautonomicganglion,andthereforetransmitsmotorimpulsesfromthecentralnervoussystemtoautonomicganglia.

31.A–ClozapineClozapineisknowntocauseagranulocytosisin1%ofpatients.Consequently,patientswillneedtohavetheirwhitecellcountmonitored regularly.Theusual testing regimen isonceeveryweek for6months,every2weeksforthenext6monthsandmonthlythereafter(assumingagranulocytosisdoesnotdevelopduringthistime).

32.B–CytosoliccalciumandcontractionofmicrotubulesG-protein receptorsare transmembrane receptorsand thereforehavea surface incontactwithboth theinsideandoutsideofacell.Chemotaxinbindingtoareceptorontheexternalsurfaceofthecellresultsinactivation of aG-protein on the inside surface.G-protein activation results in a cascade of reactions.Withinleukocytes,thisleadstothereleaseofcalciumwithinthecellcytoplasm.Calciumisrequiredforthe contraction of microtubules via actin and myosin filaments. When co-ordinated, this producesmovementoftheleukocytetowardsthechemotaxin.Thisprocessiscalledchemotaxis.

33.A–AmisulprideAmisulpride isanatypicalantipsychoticwhichisadopamineD2/D3 receptorantagonistand isused totreat the positive symptoms of psychosis. Quetiapine acts on D1-4 receptors. Olanzapine acts on D2receptorsalone.

34.B–Oculomotor,facial,glossopharyngealandvagusTheoculomotor,facial,glossopharyngealandvagusnerveshaveaxonsthatoriginatefrompreganglionicneuronswhich synapse at their respective terminal ganglia.Oculomotor preganglionic parasympatheticneurons originate from the Edinger–Westphal nucleus and end in the ciliary ganglion. Postganglionicneurons travel in short ciliary nerves to supply the sphincter pupillae muscle of the iris and ciliarymuscles,whichplayakeyroleinpupillaryconstrictioninthepupillarylightreflex.Inordertoregulatetheamountoflightenteringtheeye,thesizeofthepupilservesasacontrolledgateway.Theilluminationof the retina leads to thepupil constrictionviacontractionof the sphincterpupillaemuscleof the iris,therebymodulatingtheamountoflightreachingtheretina.Thisisknownasthedirectreflex.Theindirectreflex is when the constriction of the pupil of the non-illuminated eye takes place without directillumination of the retina – also known as the consensual light reflex. Facial preganglionicparasympathetic neuronsoriginate from the superior salivatorynucleusof thepons (secondpart of thebrain stem) and exit the brain stem in the sensory root of the facial nerve, also known as nervusintermedius. From here they travel via their terminal ganglia (submandibular and pterygopalatine) enroutetoinnervatingthesubmandibularandsublingualsalivaryglands,lacrimalgland,andnasalandoralmucous membranes. Glossopharyngeal parasympathetic neurons originate from the inferior salivatorynucleus of themedulla (third part of the brain stem),which subsequently synapsewith postganglionicneurons in the otic ganglion which essentially innervates the parotid salivary gland. Vagalparasympathetic neuronsoriginate from thedorsalmotor nucleusof thevagus,which is situated in themedulla underneath the floor of the fourth ventricle. From here they travel to the cardiovascular,respiratoryandgastrointestinalsystems.

35.B–IntegrinsMarginationofleukocytesinvolvestheformationofweakandtransientconnectionsbetweenleukocytesand the endothelium. These connections are mediated through selectin receptors expressed mainly byendothelialcells.Adhesioninvolvesastrongbondbetweenleukocytesandtheendotheliumandisformedbetween integrins expressed on leukocyte surfaces and adhesion molecules within the endothelium.Adhesion does not occur until activated by chemokines. Upregulation of selectins and endothelialadhesionmoleculesoccursduringinflammationviamediatorssuchasIL-1,TNFandhistamine.

36.C–IgGChemokinesis thenamegiventoafamilyofchemotacticcytokines.IL-8isanexampleofachemokinereleasedbymacrophagestoattractneutrophils.LeukotrieneB4,platelet-activatingfactorandC5aallcanalsofunctionchemotactically.IgGdoesnotactdirectlyasachemotacticagent;however,certainbacteria

(e.g.Staphylococcus aureus) can develop proteins to inhibit chemotaxis. The human body may thenrespondbyproducingantibodiestotheseproteins,againallowingchemotaxistooccur.

37.A–CiliaryganglionThe preganglionic neurons originating from cranial nerve III synapse at the ciliary ganglion. Theseneurons arise from the Edinger–Westphal nucleus and terminate at the ciliary ganglion wherepostganglionic neurons continue to innervate the sphincter pupillae muscle of the iris and the ciliarymusclecontainedwithintheciliarybody.

38.B–Alveolardevelopmentcontinuesuntil2yearsofageAtrachealbudisformedfromtheforegutat4–5weeks’gestation.Formationofthemajorairwaysandbronchial tree continues to 16 weeks. After 16 weeks, the last generations of the lung periphery areformed,aswellasepithelialdifferentiationandformationoftheair–bloodbarrier.After24weeks,thelungstartstoproducesurfactantsandthisisofgreatclinicalimportanceasitisonlyafterthisstagethatthe fetal lung is theoreticallyviable if thebaby is bornprematurely.Alveolardifferentiation continuesuntil8–10yearsofage.

39.D–TheengulfmentanddigestionofsolidparticlesbycellsPhagocytosisistheengulfmentanddigestionofsolidparticlesbyacell.Theintakeoffluidintoacellbyengulfmentdefinespinocytosis.Exocytosisistheprocessofexcretingsubstanceswithinacellvesiclebyfusion with its cell membrane. Programmed cell death initiated from within the cell is apoptosis.Regrowthofbloodvesselsfollowinginjurycanbedescribedasangiogenesisorrevascularization.

40.C–TypeIalveolarcellsarethickcellsprovidingstructuralintegritytothesurfaceliningTypeIalveolarcellsare thesurfaceforgasexchangeandmakeup90%of thealveolarsurface lining.Thoughtheyplayaroleinstructure,theyareactuallyverythintoenableefficientgasexchange.TypeIIalveolar cells make upmuch less of the surface lining and produce surfactant, which is important inreducingsurfacetension.

41.D–PterygopalatineganglionThe preganglionic neurons originating from cranial nerve VII synapse at the pterygopalatinesubmandibularganglion.Theseneuronsoriginateinthesuperiorsalivarynucleusofthepons.Fromhere,fibres leave the brainstem and pass to submandibular and pterygopalatine gangliawhere they synapsewithpostganglionicfibres.Fibresfromthepterygopalatineganglioninnervatethelacrimalglandandthenasalandoralmucousmembranes,whilethosefromthesubmandibularganglioninnervatesalivaryglands(submandibularandsublingualglands).TheciliaryganglionisthesiteforsynapseforcranialnerveIII,thecoeliacganglionformspartofthesympatheticdivisionandtheoticganglionisthesiteforsynapseforcranialnerveIX.

42.B–CranialnervesVII/IXFacialpreganglionicparasympatheticneuronsoriginatefromthesuperiorsalivatorynucleusofthepons(secondpartofthebrainstem)andexitthebrainsteminthesensoryrootofthefacialnerve,alsoknownas nervus intermedius. From here they travel via their terminal ganglia (submandibular andpterygopalatine) en route to innervating the submandibular and sublingual salivary glands, lacrimalgland,andnasalandoralmucousmembranes.Glossopharyngealparasympatheticneuronsoriginatefromtheinferiorsalivatorynucleusofthemedulla(thirdpartofthebrainstem)andsubsequentlysynapsewithpostganglionicneuronsintheoticganglion,whichessentiallyinnervatestheparotidsalivarygland.

43.A–CoughAcuteepiglottitisistheresultoflocalizedHaemophilusinfluenzaeinfectionofthesupraglotticlarynx.It isamedicalemergencyas the inflamedepiglottiscancausecompleteairwayobstruction.Symptomsandsignsincludefever,droolinganddysphagia.Acoughistypicallyabsent.

44.E–Increasessecretions,peristalsisandrelaxationofsphincterParasympathetic innervationof thegastrointestinalsystemresults in increasedsecretions,stimulationofperistalsisand(generally)sphincterrelaxation.Sympatheticinnervationresultsinconverseoutcomes.

45.A–LeukotrieneB4Leukotriene B4 also aids neutrophil function through chemotaxis. It is antagonized by lipoxins.Thromboxane A2 causes vasoconstriction. Prostacyclin results in vasodilation. Prostaglandins areinvolvedinincreasingthesensationofpainandtheproductionoffever.

46.B–HotpotatovoiceApatientwith aperitonsillar abscess (quinsy)may speakwith a ‘hotpotatovoice’.That is, theywillspeakasifthereisahotpotatointheirmouth!Thisisduetothedistortionofvowels.Othersymptomsmayincludepain,fever,malaiseandheadache.

47.D–ProstaglandinPGE2Eicosanoidsaremoleculesinvolvedincellsignalling.Theyareproducedasaresultofthemetabolismofarachidonic acid. Dependent upon their properties, eicosanoids can stimulate or inhibit features ofinflammation. Prostaglandin E2 (PGE2) is known to increase the sensitivity of pain receptors and isinvolved in the development of fever. Leukotrienes B4 and C4, and thromboxane A2 causevasoconstriction.Prostacyclinresultsinvasodilation.

48.A–Inhibitionofcyclooxygenase1(COX-1)The COX-1 enzyme is contained within the gastric mucosa and is involved in the production ofprostaglandinsthatprotect thestomachfromgastricerosion.Ingestionofnon-specificNSAIDs,suchasaspirin or ibuprofen, inhibits both COX-1 and COX-2 enzymes. This therefore decreases the gastricprotection provided by themucosal prostaglandins, resulting in gastric ulcers. Glucocorticoids inhibitphospholipaseA2therebyinhibitingthereleaseofarachidonicacidfromcellmembranes,witharesultantincreasedriskingastriculceration.

49.E–NicotinicreceptorsThe regulation of gastric secretion andmotility is via both neural and hormonalmechanisms. Gastricdigestionoccursinthreestages:cephalic,gastricandintestinal.Inthecephalicstage,thecerebralcortexand feeding centre in the brain send impulses to the submucosal plexus via the parasympatheticpreganglionic fibres in thevagusnerves.Thisultimately results in impulses to theparietal cells, chiefcells,mucouscellsandgastricglandswhichreleasepepsinogen,hydrochloricacid,mucousandgastrin.These impulses also increase stomach motility. In the gastric stage, food distends the stomach andstimulatesstretchreceptorsinitswalls,andchemoreceptorsmonitorthepHofthestomachchyme.Whenthese receptors are activated, they send impulses to the submucosal plexus which in turn activatesparasympathetic and enteric fibres, leading to peristalsis (the intestinal stage). This is mediated byacetylcholinevianicotinicreceptors.

50. E – Margination and rolling, adhesion of integrins to endothelium, diapedesis, chemotaxistowardssiteofinjury

Marginationdescribestheprocessbywhichleukocytesbegintoflowcloser totheendothelialsurfaceswithin a vessel. Leukocytes are described as rolling when partial bonds between themselves and theendothelium slow their progress within a vessel. Adhesion involves the formation of strong bondsbetween leukocytes and the endothelium.Diapedesis is the outward passage of blood cells through anintact vessel wall. Chemotaxis involves the movement of blood cells along a chemical concentrationgradienteithertowardsorawayfromthesource.

QuestionsPaper81.Phagocytosiscaninducethekillingofengulfedbacteriainanumberofways.Whichofthefollowingsubstanceswouldnotbebactericidal?

A. Elastase

B. Hydrogenperoxide

C. Hypochlorousfreeradical

D. Nitricoxidefreeradical

E. Reactiveoxygenspecies

2.Inwhichofthefollowingareacidhydrolaseenzymesfound?

A. Centrioles

B. Cytoplasm

C. Lysosomes

D. Ribosomes

E. Vacuoles

3.Thereisanoverlapbetweenthemanyfunctionsofgrowthfactors;however,whichofthefollowingstatementsbestdescribestheprominentfunction(s)ofplatelet-derivedgrowthfactor?

A. Angiogenesis

B. Catalysestheactionsofothergrowthfactors

C. Chemotaxisandproliferationoffibroblastsandsmoothmusclecells

D. Stimulatesaggregationofplatelets

E. Stimulatesepithelialproliferation

4.Whichofthefollowingisproducedbythepyloricregionofthestomach?

A. Gastrinonly

B. Hydrochloricacidonly

C. Mucus,hydrochloricacidandpepsinogen

D. Mucusonly

E. Pepsinogenonly

5.Beforemigrationofepithelialcellscanoccurtore-epithelializeanareafollowinginjury,whichofthefollowingneedstooccur?

A. Apoptosisofperipheralepithelialcells

B. Cross-linkedcollagendeposition

C. Detachmentofdesmosomesandhemidesmosomes

D. Erythropoietinstimulation

E. Formationofmyosinfilaments

6.A77-year-oldmanhasbeennewlydiagnosedwithatrialfibrillation.Hehasapastmedicalhistoryoftype 2 diabetes, hypertension and hyperthyroidism. What is the most appropriate anticoagulationregimenforhim?

A. Aspirinalone

B. Aspirinandclopidogrel

C. Aspirin,clopidogrelandwarfarin

D. Warfarin

E. Noanticoagulationrequired

7.Choosetheoptionbelowwhichbestdescribestheorderinwhichcutaneouswoundsundergohealing

A. Formation of fibrin clot, inflammation and cell recruitment, proliferation and deposition ofextracellularmatrix,woundcontraction

B. Formationoffibrinclot,proliferationanddepositionofextracellularmatrix,inflammationandcellrecruitment,woundcontraction

C. Inflammation and cell recruitment, formation of fibrin clot, proliferation and deposition ofextracellularmatrix,woundcontraction

D. Wound contraction, formation of fibrin clot, inflammation and cell recruitment, proliferation,depositionandorganizationofextracellularmatrix

E. Wound contraction, inflammation and cell recruitment, formation of fibrin clot, proliferation anddepositionofextracellularmatrix

8.Inahealthyadult,thenormallevelforlactateinthebloodis:

A. 0mmol/L

B. <1mmol/L

C. <1.5mmol/L

D. <2mmol/L

E. <2.5mmol/L

9.Acidaemiaisbestdefinedaswhichofthefollowing?

A. Adecreaseinthemetabolicconcentrationofhydrogenions

B. Alactatelevelof0.7mmol/L

C. ApHof7.55

D. Anincreaseintheconcentrationofbicarbonate

E. Anincreaseinthemetabolicconcentrationofhydrogenions

10.Whichofthefollowingfeaturesismoreprominentinhealingbysecondaryintention,comparedwithhealingbyprimaryintention?

A. Lackofinfectivecontaminationofthewound

B. Minimaltissuedestruction

C. Quickerhaemostasis

D. Smallerscar

E. Woundcontraction

11.VitaminCdeficiencyresultsineasilybleedinggumsduetowhichoneofthefollowing?

A. Decreasedproductionofclottingfactors

B. Inhibitionofcollagensynthesis

C. Inhibitionoffibroblastproliferation

D. InhibitionofvitaminK

E. Thrombocytopaenia

12.Histologically,agranulomacanbedescribedasanaggregateof:

A. Cuboidalepithelium

B. Eosinophils

C. Epithelioidcells

D. Mastcells

E. Microglialcells

13.Whichoneofthefollowingisnotacommontargetfordrugbinding?

A. Cellsurfacereceptors

B. Cytosol

C. Enzymes

D. Membraneionchannels

E. Transportproteins

14. Itmay takeover10daysbeforeaclinical response toantithyroiddrugs isobserved.Whichof theoptionsbelowisthemainreason?

A. Fastpharmacokineticactivityofantithyroiddrugs

B. Longactionofinhibitionofiodinationoftyrosine

C. Longhalf-lifeofT4

D. Shorthalf-lifeofT4

E. Slowpharmacokineticactivityofantithyroiddrugs

15.Whichtypeofefferentmotoneuronslocatedinthespinalcordinnervatestheintrafusalmusclefibreswithinthemusclespindle?

A. α(alpha)motoneurons

B. β(beta)motoneurons

C. δ(delta)motoneurons

D. ε(epsilon)motoneurons

E. γ(gamma)motoneurons

16.InahealthyadultthenormalrangeforbloodpHis:

A. 6.95–7.25

B. 7.15–7.35

C. 7.15–7.55

D. 7.36–7.44

E. 7.55–7.65

17.Inahealthyadultthenormalrangeforthepartialpressureofoxygeninanarterialbloodgastakeninroomairatsealevelis:

A. 5–8kPa

B. 8–10kPa

C. 10–12kPa

D. 12–13kPa

E. 13–14kPa

18. Fibroblasts are essential for the formation of granulation tissue.Which of the following is not aconstituentofgranulationtissue?

A. Collagen

B. Elastin

C. Fibronectin

D. Glycosaminoglycans

E. Interferon

19.Whichtypeofcollagenismostabundantinearlygranulationtissue?

A. TypeI

B. TypeII

C. TypeIII

D. TypeIV

E. TypeV

20.Inahealthyadultthenormalrangeforthepartialpressureofcarbondioxideinanarterialbloodgastakeninroomairatsealevelis:

A. 1.7–3kPa

B. 3.1–5kPa

C. 4.7–6kPa

D. 5.1–8kPa

E. 6.7–9kPa

21.Inahealthyadult,thenormalrangeforhydrogenionsinthebloodis:

A. 20–28nmol/L

B. 24–32nmol/L

C. 36–44nmol/L

D. 40–48nmol/L

E. 44–52nmol/L

22. A panic attack which leads to hyperventilation will characteristically lead to which acid–baseimbalance?

A. Metabolicacidosiswithrespiratorycompensation

B. Metabolicacidosiswithoutrespiratorycompensation

C. Metabolicalkalosis

D. Respiratoryacidosis

E. Respiratoryalkalosis

23.A blood film is requested for a patientwith suspected chronic inflammation. The report includedmentionof‘rouleauxformation’.Whatserumbloodtestwouldindicatethesameprocess?

A. C-reactiveprotein

B. Erythrocytesedimentationrate

C. Neutrophilcount

D. Plateletcount

E. Whitebloodcellcount

24. Non-steroidal anti-inflammatory drugs are used most extensively in the long-term management ofwhichoneofthefollowingconditions?

A. Pagetdisease

B. Pepticulcerdisease

C. Rheumatoidarthritis

D. Systemiclupuserythematosus

E. Ulcerativecolitis

25.Whatisthetraditionalmethodofquantifyingacid–baseimbalance?

A. Cockcroft–Gaultformula

B. Henderson–Hasselbalchequation

C. Modelforend-stageliverdisease(MELD)score

D. Rockallscore

E. Stewartphysicochemicalapproach

26.A34-year-oldwomanwhois26weeks’pregnantisfoundtohaveabloodpressureof160/80mmHgat two consecutive antenatal appointments. She has no proteinuria. What is the most appropriatemanagementoption?

A. Labetalol

B. Losartan

C. Methyldopa

D. Ramipril

E. Repeat the blood pressure at the next antenatal appointment and consider treatment if the bloodpressureremainsraised

27.Whichofthefollowingbestdescribestherangeofgastrointestinalside-effectswhichcanpotentiallybeinducedbyprolongeduseofnon-steroidalanti-inflammatorydrugs?

A. Diarrhoea,dyspepsia,gastritis,gastroduodenalulceration,hepatitis

B. Diarrhoea,dyspepsia,gastroduodenalulceration,villousatrophy

C. Dyspepsia,gastritis,gastroduodenalulceration,intestinalstrictureformation

D. Gastroduodenalulceration,gastritis,gastrointestinalpolypformation,nausea

E. Hepatitis,duodenitis,analfissure,gastroduodenalulceration,dyspepsia

28.Whichpartoftheduodenumisretroperitoneal?

A. Thedistalsectionofthefirstpart

B. Thesecondpart

C. Thethirdpart

D. Thefourthpart

E. Alloftheabove

29.Whichofthefollowingisthemostabundantcelltypewithinthesmallintestine?

A. Enterocytes

B. Enteroendocrinecells

C. Gobletcells

D. Panethcells

E. Stemcells

30.A32-year-oldmanrequireslong-termnon-steroidalanti-inflammatorydrugs(NSAIDs)forankylosingspondylitis.Whichofthefollowingisthemostsuitablechoiceofdrugtoco-prescribewithhislong-termNSAIDs?

A. Loperamide

B. Misoprostol

C. Omeprazole

D. Ranitidine

E. RegularGaviscon

31.Whichof thefollowinglistsdescribesthemainpotentialcomplicationstobothmotherandbabyoflong-termnon-steroidalanti-inflammatorydrugadministrationinthelaterstagesofpregnancy?

A. Delayedonset and increaseddurationof labour,prematureclosureofductusarteriosus,persistentpulmonaryhypertensionofthenewborn

B. Delayedonsetoflabour,meconiumaspirationsyndrome,respiratorydistresssyndrome

C. Delayedonsetoflabour,prematureclosureofductusarteriosus,meconiumaspirationsyndrome

D. Prematureonsetoflabour,delayedclosureofductusarteriosus,persistentpulmonaryhypertensionofthenewborn

E. Prematureonsetoflabour,prematureclosureofductusarteriosus,respiratorydistresssyndrome

32.Whichofthefollowingisthefirst-linemanagementofaCaucasianhypertensivepatientundertheageof55?

A. Angiotensin-convertingenzymeinhibitor

B. Beta-blocker

C. Calciumchannelblocker

D. Loopdiuretic

E. Thiazidediuretic

33.Whichoneofthefollowinghasanantiparallelorientationofitstetramers?

A. Actinfilaments

B. Centrioles

C. Intermediatefilaments

D. Microtubules

E. Noneoftheabove

34.Whichofthefollowingcelltypesisclassicallyfoundastheliningalveoli?

A. Columnarepithelium

B. Cuboidalepithelium

C. Squamousepithelium

D. Transitionalepithelium

E. Noneoftheabove

35.Anobese76-year-oldmanhasapastmedicalhistoryoftype2diabetesmellitusdiagnosed29yearsago.Onroutineattendance tohisGPforfollow-uphe isfoundtohaveabloodpressureof166/92mmHg.Whichofthefollowingmanagementoptionsisthemostsuitable?

A. Amlodipine5mg

B. Atenolol50mg

C. Bendroflumethiazide2.5mg

D. Ramipril2.5mg

E. Ramipril10mg

36.A64-year-oldwomanpresentswithalonghistoryofhypertension.Shehasbeenon10mgamlodipineformany years, and on routine check-up her blood pressure is found to be 162/96mmHg.A fewweekslateritisre-checkedandrecordedas164/92mmHg.Whatisthemostappropriatemanagementoption?

A. Addbendroflumethiazide2.5mg

B. Addbisoprolol5mg

C. Addramipril5mg

D. Increasetheamlodipineto15mg

E. Stopamlodipineandchangetoramipril10mg

37.Boneisderivedfrom:

A. Ectoderm

B. Endoderm

C. Mesoderm

D. Alloftheabove

E. Noneoftheabove

38.Whichofthefollowingcelltypesclassicallyhasabasalnucleus?

A. Columnarepithelium

B. Cuboidalepithelium

C. Squamousepithelium

D. Transitionalepithelium

E. Noneoftheabove

39.Whichofthefollowingbestdescribesasyndesmosis?

A. Ajointthatallowsthegreatestmobility

B. Ajointwithlimitedmovementinwhichbonesarecoveredbyahyalinecartilageonthearticulatingsurface

C. Ajointwithlimitedmovementwherethebonesarejoinedbyahyalinecartilage

D. Ajointwithlimitedmovementwherethebonesarejoinedbyaninterosseousmembrane

E. Anon-moveablejointwherethebonesareconnectedbybonetissueordenseconnectivetissue

40.Whichofthefollowingcelltypescontaingranuleswhichaccumulateattheapicalendofthecell?

A. Enterocytes

B. Enteroendocrinecells

C. Gobletcells

D. Panethcells

E. Stemcells

41.Keloidscarsoccurasaresultofwhichofthefollowing?

A. Depositionofexcessiveamountsofcollagenduringscarformation

B. LackofvitaminC

C. Reducedelastindeposition

D. Reducedironabsorption

E. Woundspenetratingdeepintothedermis

42.Degradationofcollagenandotherextracellularcomponentsiscommonlyundertakenbywhichoneofthefollowingenzyme?

A. Cyclooxygenase

B. Elastase

C. HMG-CoAreductase

D. Matrixmetalloproteinases

E. Myeloperoxidase

43.Whichpartofthesmallintestineischaracterizedbythepresenceofplicaecirculares?

A. Caecum

B. Duodenum

C. Jejunum

D. Proximalileum

E. Terminalileum

44.Whichoneofthefollowingorganellesisstuddedwithribosomes?

A. Golgiapparatus

B. Mitochondria

C. Nucleus

D. Roughendoplasmicreticulum

E. Smoothendoplasmicreticulum

45.Whichoneofthefollowingmaintainscellshapeandenablescellularmotion?

A. Centrioles

B. Cytoplasm

C. Cytoskeleton

D. Vacuoles

E. Vesicles

46.Which of the following cell type is found in the bases of the intestinal crypts and contains largeacidophilicgranules?

A. Enteroendocrinecells

B. Enterocytes

C. Gobletcells

D. Panethcells

E. Stemcells

47.Whichofthefollowingdrugsmaybeassociatedwithadrycough?

A. Amiodarone

B. Atenolol

C. Isosorbidemononitrate

D. Lisinopril

E. Losartan

48.Thenormalrangeforactualbicarbonateinthebloodis:

A. 10–18mmol/L

B. 16–23mmol/L

C. 21–28mmol/L

D. 25–30mmol/L

E. 28–32mmol/L

49.Whichofthefollowingisclassicallyfoundastheapicallayerofepithelium?

A. Columnarepithelium

B. Cuboidalepithelium

C. Keratinizedepithelium

D. Squamousepithelium

E. Transitionalepithelium

50.WhatisthepHwithinthelumenofthestomach?

A. 1–2

B. 2–4

C. 4–6

D. 6–8

E. 8–10

AnswersPaper81.A–ElastaseReactive oxygen species (including hydrogen peroxide) and free radicals cause cellular damage tobacterialcellsandtheirDNA,leadingtodeathbyapoptosis.Elastaseisanenzymethatwilldegradeamicroorganismonceithasalreadybeenkilled.

2.C–LysosomesLysosomesarespecializedvesiclescontainingacidhydrolaseenzymes,whichdigestwastematerialsandcellulardebris.Vesiclesingeneralarebubblesofliquidwithinacellthatareusedtostore,transportordigestcellularproducts.Aribosomeisresponsiblefortheproductionofproteinsfromaminoacids.Theyaredividedintotwosubunits.ThesmallerofthetwobindstomessengerRNA(mRNA)andthelargertotransferRNA(tRNA).Vacuolesareenclosedcompartmentscontaininginorganicandorganicmoleculessuch as enzymes in solution. The cytoplasm is the part of the cell enclosed by the cell membrane.Centriolesarecylindricalstructuresmadepredominantlyoftheproteintubulinwhichareimportantintheorganizationofthecytoplasmandcelldivision.

3.C–ChemotaxisandproliferationoffibroblastsandsmoothmusclecellsPlatelet-derivedgrowthfactor(PDGF)ischemotactictomonocytes,fibroblastsandsmoothmusclecells,andcanbesecretedbymacrophages.Withinhealingtissues,itprovidesanimportantroleinextracellularmatrix formation via fibroblast and smooth muscle cell proliferation. Epithelial growth factor (EGF)stimulates epithelial proliferation. Angiogenesis is stimulated by vascular endothelial growth factor(VEGF)andfibroblastgrowthfactor(FGF).PDGFsharessomeroleinangiogenesis.HypoxiaisastrongstimulantofVEGFsecretion.Insulin-likegrowthfactor-1(IGF-1)hassynergisticactionswithanumberof factors. Adenosine diphosphate (ADP) and thromboxane A2, rather than PDGF, are involved instimulatingplateletaggregation.

4.D–MucusonlyIn thecardiaandpyloricregionsof thestomachonlymucus isproduced.In thebodyandfundusof thestomachmucus,hydrochloricacidandpepsinogenareproduced.Gastrinisonlyproducedintheantrum.

5.C–DetachmentofdesmosomesandhemidesmosomesDesmosomes are structures joining two adjacent epithelial cells. Hemidesmosomes anchor epithelialcells to the basement membrane. Loosening of these connections is necessary in order for epithelialproliferationandmigrationoverawound.Migrationoccursviaactinmicrofilamentsformedwithin theepithelial cells.Erythropoietin is ahormone released from thekidneys that stimulates theproliferationand maturation of red blood cells (erythrocytes). Organization of collagen and strengthening viacrosslinksonlyoccurlateroninthehealingprocess.Re-epithelializationisoneofthefirststepsandaidsgranulationtissueformation.

6.D–WarfarinCurrentguidelines suggest thatpatientswithnon-rheumaticatrial fibrillationare risk stratifiedprior tocommencinganticoagulationtreatment.Toriskstratifypatients,theCHA2DS2–VAScscoringsystemcan

beapplied.Thecriteriaare:

CCongestiveheartfailure

HHypertension(BP>140/90ortreatedhypertension)

A2Age≥75

DDiabetesmellitus

S2Priorstroke,TIAorthromboembolism

VVasculardisease(peripheralarterialdisease,myocardialinfarction)

AAge65–74

ScSexcategory(i.e.femalesex)

For each of the above criteria, one point is added, with the exception of age ≥75 and priorTIA/stroke/thromboembolism, where two points are added. In patients scoring 2 or above, oralanticoagulationshouldbestarted.Thosewhoareat lowrisk (definedasascoreof0 inmalesor1 infemales) requireno anticoagulation.Males scoring1 are stratified as being atmoderate risk, andoralanticoagulation is recommended. The patient in this scenario scores 4 points (2 for age, 1 forhypertension,1fordiabetes),thereforeheshouldbeonwarfarin.

7.A–Formationof fibrin clot, inflammationand cell recruitment,proliferationanddepositionofextracellularmatrix,woundcontractionInitiallyfollowinginjurytotheskin,bleedingoccurs,whichstimulatesvasoconstrictionwithactivationofplatelets and the clotting cascade. Vasodilation follows with inflammatory infiltrate, chemotaxis ofinflammatory cells and removal of injured tissues. Proliferation then occurs and includes re-epithelialization, angiogenesis and collagen deposition.Wound contraction occurs at 1–2 weeks post-injury,followedbyremodellingofcollageninordertoregainthestrengthofthetissue.

8.D–<2mmol/LLactate is constantly produced from pyruvate and constantly removed through gluconeogenesis andoxidation.Itcanbeproducedinhigheramountsincriticallyillpatients,leadingtoacidaemia.Notethatthereisanincreasedmortalityincriticallyillpatientswitharaisedlactate.

9.E–AnincreaseinthemetabolicconcentrationofhydrogenionsAcidaemia isdefinedasapH<7.36,whichcorrelates toahydrogenconcentrationofgreater than44nmol/L.IncreasedbicarbonateconcentrationsmayincreasethepHsoitmaybecomealkalotic.ApHof7.55isdefinedasalkalotic.

10.E–WoundcontractionWoundsthathealbysecondaryintentionarethosewhichresultfrommoreextensivetissuelossorrequirealongerhealingperiodduetocontaminationwithinfectiveorganisms.Woundcontractionisundertakenbymyofibroblastsandisneededfortheselargerwounds,andwillusuallyresultinalargerscar.Timeto

haemostasismaybeprolongedwithwoundshealingbysecondaryintention,becausetheremayhavebeengreaterdestructionofvasculature.

11.B–InhibitionofcollagensynthesisThe strength of collagen comes from its ability to form crosslinks. This process is dependent uponascorbicacid(vitaminC).

12.C–EpithelioidcellsEpithelioidcells are activatedmacrophageswhichhavechanged in shape to resembleepithelial cells.Theyareanessentialcharacteristicofgranulomas.

13.B–CytosolAdrugisachemical thathastheabilitytoalter thefunction/responseofamolecule.Adrugtarget isaphysicalandchemical structure thathas theability to interactwith thesechemicals.Anystructurewiththis ability can be considered a drug target, and useful drug targets are those that can interact withchemicalsandproduceaclinicallybeneficial response.Commondrug targetsareas listed in theotheroptions.Cytosol, the fluid substanceofcytoplasm, isnotadrug target though itmayholddrug targets,suchasnuclearreceptors,insuspension.

14.C–Longhalf-lifeofT4Thioureylenes,suchascarbimazoleandpropylthiouracil,havea fastpharmacokineticaction, inhibitingtyrosine residue iodination on thyroglobulin and thus reducing thyroid hormone synthesis. The clinicalresponse is still slow andmay take several days however, due to the long half-life ofT4 (thyroxine).ExistingT4willpersistforsometimeandhencestillcauseclinicalsymptomsofhyperthyroidism.Itisonly when the existing hormones are eradicated that the fast pharmacokinetic action of antithyroidmedicationswillproduceaclinicaleffect.

15.E–γ(gamma)motoneuronsSomatic motoneurons are divided into only two types: alpha and gamma. The gamma-motoneuronsinnervatetheintrafusalmusclefibreswithinthemusclespindle.Theyareusedtoregulatethesensitivityofthespindletomusclestretching.Thealpha-motoneuronsinnervateextrafusalmusclefibreswithinthemuscle.Thealpha-motoneuronsareoftencalled theventralhornneurons, as their cellbody is locatedwithintheventralhornofthespinalcord.Theycontributetothemuscletonegeneratedwhenamuscleisinanon-contractedstate.

16.D–7.36–7.44The normal value for blood pH is between 7.36 and 7.44. Any lower or higher would indicate anacidaemiaoralkalaemia,respectively.

17.D–12–13kPaThenormalarterialpartialpressureofoxygeninroomairatsealevelis12–13kPa.Thisisthevalueforayounghealthyadult,andthenormalrangewilldecreasewithage.

18.E–InterferonAllofthecomponentslistedcanbesynthesizedbyfibroblasts;however,interferonsdonotcontributetothe granulation tissue scaffolding formed within healing wounds. Interferons aid the immune system’sresponseagainstviralinfection.

19.C–TypeIIITypeIisthemostabundanttypeofcollagenwithintheskin,buttypeIIIcollagenismostabundantinearlygranulationtissue.Duringmaturationofcollagenfollowingcutaneousinjury,typeIIIcollagenisreplacedwithtypeI.

20.C–4.7–6kPaIn a normalyounghealthy adult, thenormal range for partial pressureof carbondioxide in an arterialbloodgastakenatsealevelwhenbreathingroomairis4.7–6kPa.Ifthereisaconstantmetabolicrate,the PaCO2 is determined only by ventilation. If hypoventilating, the PaCO2 will rise, leading to arespiratoryacidosis,andifhyperventilatingthePaCO2willdecrease,leadingtoarespiratoryalkalosis.

21.C–36–44nmol/LThenormalrangeofhydrogenionsinthebloodisbetween36and44nmol/L.ThisequatestothenormalpHrangeofbetween7.36and7.44.

22.E–RespiratoryalkalosisHyperventilationwill lead to the lossofcarbondioxide,which leads to the lossofwater.ThesehavedissociatedfromH2CO3.HCO3−+H+H2CO3andH2CO3CO 2+H2O.The lossofhydrogen ions,asseenintheseequations,resultsinanalkalosis.

23.B–ErythrocytesedimentationrateWhenfibrinogenbindstoerythrocytes,itcausesthemtoformaggregates,orrouleaux.Thisincreasestherate at which they sediment when compared to individual red blood cells, hence increasing theerythrocytesedimentationrate.Anabundanceoffibrinogenoccurswithinflammatorystates.

24.C–RheumatoidarthritisNSAIDs are used in a wide range of chronic inflammatory disorders, and therefore their use inrheumatologyisprominent.Theirlargestsingleuseisprobablyinthemanagementofrheumatoidarthritis,a condition in which excess tumour necrosis factor (TNF)-α production leads to joint destruction,although they are used in conditions such as systemic lupus erythematosus to a lesser extent.NSAIDsshould be co-prescribedwith a proton-pump inhibitor if used long term to protect the gastroduodenalmucosafromulceration.Regularmonitoringofrenalfunctionshouldalsobeperformed.Theavailabilityof disease-modifying therapies and biologic agents such as infliximab (anti-TNF-α monoclonalantibodies)hassignificantlyreducedtheneedforlong-termNSAIDuse.

25.B–Henderson–HasselbalchequationThe Henderson–Hasselbalch equation is used to find the equilibrium pH in acid–base reactions. TheStewartapproachisanewermethodofacid–baseanalysis,withthefocusonelectronneutralityversuspHcontrol.TheCockcroft–Gaultformula isforcreatinineclearance,MELDscore isforassessmentofend-stageliverdiseaseandtheRockallscoreisusedto identifypatientsatriskofanadverseoutcomefollowingacuteuppergastrointestinalbleeding.

26.A–LabetalolThis patient has gestational hypertension, which is defined as new hypertension presenting after 20weeks’ gestation without significant proteinuria. First-line treatment is oral labetalol with the aim ofkeepingthediastolicbloodpressurebetween80and90mmHgandthesystolicbloodpressureunder150mmHg.Withabloodpressureashighas160/80mmHg,thepatient in thisscenariowouldalsorequire

admission to hospital. Ramipril is contraindicated during pregnancy and breastfeeding, as is losartan.Methyldopaisnolongertheagentofchoicebutcanbeusedifthereisacontraindicationtobetablockers,suchasasthma.Thesignificanceoftheabsenceofproteinuriaisextremelyimportantinapregnantwomantoensurethatthisisnotpre-eclampsia.

27.A–Diarrhoea,dyspepsia,gastritis,gastroduodenalulceration,hepatitisAlthoughtherangeofgastrointestinalside-effectscausedbyNSAIDsisdiverse,NSAIDsarenotknowntobeassociatedwithpolypformation,villousatrophy,analfissuresorstrictureformation.

28.E–AlloftheaboveApart from the first 2 cm of the first part of the duodenum, it is all retroperitoneal and consequentlyimmobile.

29.A–EnterocytesEnterocytes are the most abundant cell type in the small intestine. They are tall columnar cells withmicrovilliandabasalnucleus.Theyarespecializedcellsandservetoabsorbandtransportsubstancesinandout of the lumen.Theyhave a short lifespan,which allows for the continualwear and tear of theintestinalmucosa.

30.C–OmeprazoleWithlong-termNSAIDtherapy,gastroprotectionagainstulcerationiscrucial.Themostsuitablechoiceinthevastmajorityofpatientsisaproton-pumpinhibitor,suchasomeprazole.H2-receptorblockers,suchas ranitidine, protect against duodenal ulcers but have little protective effect against gastric ulcers.Misoprostolisanalternative,althoughdiarrhoeaandabdominalpainarefrequentandtroublesomeside-effects.

31.A –Delayed onset and increased duration of labour, premature closure of ductus arteriosus,persistentpulmonaryhypertensionofthenewbornThemain potential complications of long-termNSAIDuse in later pregnancy are a delayed onset andincreased duration of labour, premature closures of the ductus arteriosus and persistent pulmonaryhypertensionofthenewborn.NSAIDsinhibitprostaglandinsynthesis,whichisthemechanismbywhichlong-term use in the third trimester results in these complications. Prostaglandins are important inpromotingmyometrialcontractionsandthereforeintheinitiationoflabour.Afallinprostaglandinlevelsatbirthisinpartresponsibleforcontractionofthevascularsmoothmuscleoftheductusarteriosuswalland therefore itsclosure.NSAIDs reversebothof theseprocesses,hencedelayedonsetandprolongeddurationoflabourandprematureclosureoftheductusarteriosus.

32.A–Angiotensin-convertingenzymeinhibitorCurrentguidelinessuggestthatpatientsundertheageof55,whoarenon-black,shouldbetreatedwithanACEinhibitor.Beta-blockershavefallenoutoffavourformanaginghypertensionastheywerefoundnottoreducetheincidenceofmortality.Useofeitheracalciumchannelblockerordiureticisrecommendedforpatientswhoareovertheageof55,orwhoareblack.

33.C–IntermediatefilamentsIntermediate filamentshaveanantiparallelorientationof their tetramers andconsequently,unlikeotherfilaments, are not polarized. Actin filaments are assembled into two arrangements. Bundles can becomposedofpolar(allbarbedendspointtothesameendofthebundle)ornon-polar(barbedendspoint

towardsbothends)arraysoffilaments.Microtubulesarepolymersofα-andβ-tubulindimers.Thetubulindimerspolymerizeend-to-endinprotofilaments.

34.C–SquamousepitheliumSquamous cells are thin flat cells which fit closely together. Their nuclei are flattened and elliptical.Squamouscellsclassically line thealveoli toallowpassivediffusion.Cuboidalcellsappearsquare incross-sectionandarecommonlyfoundinsecretiveorabsorptivetissue,suchasinthesecretorypancreas.Columnar cells are elongated with basal nuclei. They form the lining of the stomach and intestines.Transitionalepithelium(urothelium)isatypeoftissuewhichhastheabilitytocontractandexpand.Theycan appear to look like cuboidal or columnar cells. This ability to change shape allows the cells toaccommodatefluctuationsinvolumewithinthebladder.

35.D–Ramipril2.5mgGuidelinessuggest thatdiabeticpatientsshouldhavea targetbloodpressureof<130/80mmHg.Whiletherewill be a beneficial effect of reducing the blood pressure by anymeans,ACE inhibitors conferadditionalbenefitbyreducingmicroalbuminuria indiabeticpatients.Astartingdoseof ramipril10mgwouldbeexcessive.Renalfunctionmustbemonitoredandthedosegraduallytitrateduptothemaximumtolerateddoseformaximalcardiovascularbenefit.

36.A–Addbendroflumethiazide2.5mgThemaximumlicenseddoseofamlodipineis10mg.Bothramiprilandbisoprololarenottheappropriatenextmanagementsteps inaccordancewithcurrentNICEguidelines. It isnever recommended tostopamedication simply because optimum blood pressure has not been achieved, merely to swap it for adifferent one. NICE guidelines recommend the addition of a diuretic to an existing calcium channelblockerinhypertensiveindividualsovertheageof55,orwhoareblack.

37.C–MesodermBoneandcartilagearesomeofthemanytissuesderivedfromthemesoderm.Themesodermisoneoftheprimarygermlayersandalsogivesrisetomuscle,connectivetissueandthemid-layeroftheskin.

38.A–ColumnarepitheliumColumnar cells are elongated with basal nuclei. They form the lining of the stomach and intestines.Squamous cells are thin flat cells which fit closely together. Their nuclei are flattened and elliptical.Squamouscellsclassically line thealveoli toallowpassivediffusion.Cuboidalcellsappearsquare incross-sectionandarecommonlyfoundinsecretiveorabsorptivetissue,suchasinthesecretorypancreas.Transitionalepithelium(urothelium)isatypeoftissuewhichhastheabilitytocontractandexpand.Thesecells may look like cuboidal or columnar cells. This ability to change shape allows the cells toaccommodatefluctuationsinvolumewithinthebladder.

39.D–AjointwithlimitedmovementwherethebonesarejoinedbyaninterosseousmembraneAninterosseousmembrane,suchasthetibiofibularmembrane,isanexampleofasyndesmosisjoint(i.e.ajointwithlimitedmovementjoinedbyconnectivetissue).Asynchondrosisjointhaslimitedmovementandisconnectedbyhyalinecartilage,suchasthejointsbetweentheribsandthesternum.Asymphysisisajointwherethereislimitedmovementbutthebonesinvolvedhavehyalinecartilageontheirarticulatingsurface,suchasthepubicsymphysis.Finally,adiarthrosisjointallowsgreatermobilityandalsohasasynovialfluidcontainedwithinthejoint,forexampletheknee.

40.C–Gobletcells

Gobletcellsarethesecondmostcommonepithelialcelltypeinthegastrointestinaltract.Theyincreaseinnumber along the lengthof the intestine.They containmucousgranuleswhich accumulate at the apical(luminal)endofthecell,thusgivingthecellagoblet-shapedappearance.Themucussecretedfacilitatesthepassageofmaterialthroughthebowel.

41.A–DepositionofexcessiveamountsofcollagenduringscarformationKeloidformationoccursasaresultofexcessivecollagendeposition,andthescarthatformscanextendbeyondtheoriginallimitsofthewound.Keloidformationismorecommoninpeopleofblackethnicity.Evenarelativelysuperficialepithelialinjurycanresultinakeloidscarinasusceptibleindividual.

42.D–MatrixmetalloproteinasesMatrixmetalloproteinases (MMPs) are proteolytic enzymes that degrade collagen, elastin, fibronectin,lamininandglycosaminoglycans.

43.C–JejunumTheplicaecirculares,orvalvulaeconniventes,arelargeflapswhichprojectintothelumenofthebowel.They are present throughout the small intestine but are most prominent in the jejunum. They extendtransverselyforuptotwo-thirdsofthecircumferenceofthelumen.Plicaecircularesslowthepassageoffoodandincreasethesurfaceareaforabsorption.

44.D–RoughendoplasmicreticulumRough endoplasmic reticulum is so called because of the presence of ribosomes bound to its surface.Theyarenotastablepartofthestructureastheyareconstantlybeingreleasedfromthemembrane.

45.C–CytoskeletonThe cytoskeleton is a dynamic structure which is able to maintain cellular shape and allow cellularmotion. It isalso important in themovementofvesiclesandorganelles.Vesiclesarebubblesof liquidwithinacellandareusedtostore,transportordigestcellularproducts.Aribosomeisresponsiblefortheproduction of proteins from amino acids. They are divided into two subunits. The smaller of the twobinds to messenger RNA (mRNA) and the larger to transfer RNA (tRNA). Vacuoles are enclosedcompartmentscontaininginorganicandorganicmoleculessuchasenzymesinsolution.Cytoplasmisthepartofthecellenclosedbythecellmembrane.Centriolesarecylindricalstructuresmadepredominantlyoftheproteintubulinwhichareimportantintheorganizationofthecytoplasmandcelldivision.

46.D–PanethcellsPanethcellsarefoundthroughouttheintestinaltract.Theycontainzincandlysozyme.Theyarethoughttocontribute to host defence and the regulation of intestinal flora. Enterocytes are themain cells of theintestine,gobletcellssecretemucousandstemcellsareabletobecomeanytypeofintestinalcell.

47.D–LisinoprilAngiotensin-converting enzyme (ACE) inhibitors are associatedwith a dry cough in some individuals.Thisisthoughttobeduetobradykinininthelungs,asACEnormallymetabolizesbradykinin.Itisadvisedtotransferpatientssufferingwiththisside-effecttoanangiotensinreceptorblocker,suchaslosartan.

48.C–21–28mmol/LThenormalrangeforcirculatingactualbicarbonateisapproximately21–28mmol/L.Thisisthevaluefora young healthy adult kept under standard conditions, i.e. at 37°C andwith a PaCO2 of 5.3 kPa. Thisprovides normalized respiratory conditions which eliminate changes in bicarbonate resulting from

potentiallyabnormalpatientrespiration.Alsonotethatthenormalrangeforstandardbicarbonateis21–27mmol/L.

49.C–KeratinizedepitheliumKeratinizedepitheliumisusuallythemostapicallayerofepithelium.Thesecellsaredeadandlosetheirnucleusandcytoplasm.Theycontainkeratinwhichisatough,fibrousandwaterproofprotein.

50.A–1–2Within the stomachapproximately2Lofacid isproducedperday.Thisequates toapproximately150nmol/Lhydrogenions.ThereforethepHinthelumenofthestomachislow–between1and2–comparedwithbetween6and7attheepithelialsurface.

QuestionsPaper91.Whichofthefollowingissecretedbygastricchiefcells?

A. Gastrin

B. Intrinsicfactor

C. Pepsinogen

D. Secretin

E. Noneoftheabove

2.Whichofthefollowingisnotacauseofpost-renalkidneyinjury?

A. Benignprostatichyperplasia

B. Dehydration

C. Invasivepelvictumour

D. Renalcalculi

E. Urethralstricture

3.Whichoneofthefollowingstatementsregardingthebodyfluidcompartmentsisincorrect?

A. Extracellularfluidisfurtherdividedintointerstitialfluidandplasma.

B. Extracellularsodiumishigherthanintracellularsodium.

C. Interstitialfluidhasahigherproteincontentthanplasma.

D. Theconcentrationofpotassiumishigherinintracellularthanextracellularfluid.

E. The intracellular compartment has approximately double the volume of the extracellularcompartment.

4.Fromwhichpart(s)ofthestomachisintrinsicfactorsecreted?

A. Antrum

B. Body

C. Cardia

D. Fundus

E. Fundusandbody

5.Whichofthefollowingisthefirstphaseofgastricsecretion?

A. Cephalicphase

B. Gastricphase

C. Intestinalphase

D. Secretoryphase

E. Noneoftheabove

6.Thesinoatrialnodeusuallyderivesitsbloodsupplyfromwhichofthefollowingcoronaryarteries?

A. Diagonalartery

B. Leftanteriordescendingartery

C. Leftcircumflexartery

D. Obtusemarginalartery

E. Rightcoronaryartery

7.Bywhichofthefollowingmechanismsdoloopdiureticspromotediuresis?

A. Antidiuretichormoneinhibition

B. Carbonicanhydraseinhibition

C. H+/K+transporterinhibition

D. Na+/H+pumpstimulation

E. Na+/K+/2Cl−co-transportinhibition

8.Whichoneofthefollowingstatementsregardingurineformationbythekidneyiscorrect?

A. Primaryfiltrationoccursattheproximaltubule.

B. ReabsorptiontakesplaceatBowman’scapsule.

C. Secretionofelectrolytesoccursintotheglomerulus.

D. Sodiumisreabsorbedbypassivediffusion,alongwithpotassiumandchlorideions.

E. Thevolumeofwater reabsorbed from the collectingductdependson thepresenceof antidiuretichormone.

9.A7-year-oldboyistakentohisGPbyhisconcernedmotherregardingasorethroat.TheGPdiagnosesa minor viral upper respiratory tract infection. However, an incidental finding of a ‘machine-likemurmur’justbelowtheleftclavicleisheard.Whatisthediagnosis?

A. Aorticcoarctation

B. Atrialseptaldefect

C. Normalphysiologicalmurmur

D. Patentductusarteriosus

E. Ventricularseptaldefect

10.Reninissecretedbythekidneyinresponsetoreducedrenalperfusion.Whichoneofthefollowingstatementsbestdescribestheactionofthishormone?

A. Itcausesvasodilatationoftheglomerulus.

B. Itcleavesangiotensinogentoaldosterone.

C. ItconvertsangiotensinogentoangiotensinI.

D. ItconvertsangiotensinItoangiotensinII.

E. Itreducesbloodpressurebypromotingdiuresis.

11. A 64-year-old man who recently retired from work in the dye industry presents with painlesshaematuria.Biopsyatcystoscopydiagnosesbladdercarcinoma.Whichof thefollowingis themostcommontypeofurothelialcancer?

A. Adenocarcinoma

B. Columnarcellcarcinoma

C. Myosarcoma

D. Squamouscellcarcinoma

E. Transitionalcellcarcinoma

12.Parietalcellsproducewhichofthefollowing?

A. Gastricacid

B. Gastrin

C. Pepsin

D. Pepsinogen

E. Secretin

13.Whichofthefollowingcellssecreteintrinsicfactor?

A. Chiefcells

B. Enteroendocrinecells

C. Mucouscells

D. Parietalcells

E. Noneoftheabove

14.Whichofthefollowingisnotacauseofincreasedplasmaurea?

A. Acuterenalfailure

B. Dehydration

C. High-proteindiet

D. Pregnancy

E. Uppergastrointestinalbleeding

15.Whichoneofthefollowingisnotafunctionofthekidney?

A. Eliminationofdrugsandmetabolicwasteproducts

B. Regulationofacid–basebalance

C. Regulationofbloodpressure

D. Regulationoferythrocyteproduction

E. Stimulationoftheinnateimmuneresponse

16.Whichoneofthefollowingstatementsregardingtheprocessofapoptosisiscorrect?

A. Apoptosishinderswoundhealing.

B. Apoptosisisonlyinitiatedviaamitochondrial-dependentintrinsicpathway.

C. Apoptosisisonlyinitiatedviaextrinsicmechanismsthataretriggeredbydeathreceptorsonthecellsurface.

D. ApoptosisrequiresATPasanenergysource.

E. Apoptosisresultsintheinfluxofionsandwatercausingcelllysis.

17.Thevolumeofanatomicaldeadspaceinanaverageadultis:

A. 50mL

B. 150mL

C. 300mL

D. 500mL

E. 1L

18.Which one of the following statements regarding the role of the kidneys in acid–base balance iscorrect?

A. AplasmapHof7.25willbecompensatedbyreducedrenalHCO3−reabsorption.

B. HydrogenionsecretionoccursviaH+-ATPaseandNa+/H+co-transporters.

C. Renalcompensationoccursacutely(withinhours)inrespiratoryalkalosis.

D. Respiratory acidosis results in a reduction of H+ secretion by the renal tubules and reducedreabsorptionofHCO3−.

E. TheHenderson–Hasselbalchequationisusedtocalculaterenalperfusionindisordersofacid–basebalance.

19.Whichoneofthefollowingfactorsdecreasesthevolumeofanatomicaldeadspace?

A. Bronchodilators

B. Headofsubjecttiltedforward

C. Increasingsizeofsubject

D. Increasingtidalvolumeofsubject

E. Youngerageofsubject

20.Whichoneofthefollowingstatementsregardingtheroleofapoptosisiscorrect?

A. Self-reactingB-cellsundergoapoptosisinthethymusmorecommonlythanT-cells.

B. T-cellsthatreactwithselfmajorhistocompatibilitycomplexproteinsaredestroyedbyapoptosisinthethymusinaprocesscalled‘peripheraltolerance’.

C. T-cellswithantigenreceptorsto‘self-antigens’aredestroyedbyapoptosisinthethymus.

D. T-cellswithantigenreceptorsundergonecrosisinaprocesscalled‘negativeselection’.

E. Toleranceensuresthatexternal‘foreign’stimulidonotelicitanimmuneresponseafterfoetallife.

21.Optimalgasexchangebytherespiratorytractismetbythefollowingcharacteristics,except:

A. Thetracthasalargegaspermeablesurfacearea.

B. Thetracthasaneffectivesystemforgasdeliverytothealveoli.

C. Thetractisabletowarmandhumidifyinhaledgases.

D. Thetractisopentotheatmosphere.

E. Thereisasmalldeoxygenatedbloodsupplyincloserelationtothegaspermeablesurface.

22.Whatisthetidalvolumeinanaverageadult?

A. 250mL

B. 500mL

C. 1000mL

D. 1500mL

E. 2000mL

23.Whichvesselsuppliesapproximately75%oftheliver’sblood?

A. Cysticartery

B. Hepaticartery

C. Hepaticvein

D. Portalvein

E. Splenicartery

24.Whichofthefollowingvaluesareincorrect?

A. Functionalresidualcapacityisaround2.7Lintheaverageadult.

B. Intrapleuralpressurerangesfrom–0.5to–1.0cmH2O.

C. Residualvolumeisaround1.2Lintheaverageadult.

D. Tidalvolumeisaround0.5Lintheaverageadult.

E. Totallungcapacityisaround4.8Lintheaverageadult.

25.ThenormalP–RintervalonanECGshouldbe:

A. <0.12seconds

B. 0.12–0.2seconds

C. 0.38–0.42seconds

D. >0.2seconds

E. >0.4seconds

26.WhichvesselisusuallyfoundinCalot’striangle?

A. Cysticartery

B. Hepaticartery

C. Hepaticvein

D. Portalvein

E. Splenicartery

27.TheTwaveofanECGrepresents:

A. Atrialdepolarization

B. Atrialrepolarization

C. Ventriculardepolarization

D. Ventricularfilling

E. Ventricularrepolarization

28.Whichofthefollowingisanexampleofazymogen?

A. Gastrin

B. Intrinsicfactor

C. Pepsinogen

D. Secretin

E. Noneoftheabove

29.Themainspreadofdepolarization,fromtheinsideoutthroughthebaseoftheventricles,describeswhichofthefollowing?

A. Pwave

B. Qwave

C. Rwave

D. Swave

E. Twave

30.A slim66-year-oldwomanwho is a lifelong smoker presents to the emergencydepartmentwith acough productive of yellow sputum and left-sided chest pain. She looks short of breath and hasoxygensaturationlevelsof84%onair.HerJVPisnotelevatedandshehasnoperipheraloedema.Therestofherobservationsareas follows: temperature38.1°C,BP100/56mmHg,pulse110/minandirregular.AroutineECGisdone.WhatwouldyouexpecttheECGtoshow?

A. Acompletelynormaltrace

B. Atrialfibrillationwithgloballysmallcomplexes

C. Changesconsistentwithanacutemyocardialinfarction

D. Electricalalternans

E. SIQIIITIII

31.A15-year-oldgirlisfoundtohaveadifferencebetweenherarmandlegbloodpressures,withthearmpressuresbeingmarkedlyhigher.Sheisalsonotedtohaveawidecarryingangle,webbedneckandwidelyspacednipples.Whatisthemostlikelycauseofthebloodpressuredifference?

A. Aorticcoarctation

B. Aorticstenosis

C. Dissectionofthethoracicaorta

D. Mitralregurgitation

E. Congestiveheartfailure

32.Enterochromaffin-likecellsreleasewhichofthefollowing?

A. Acetylcholine

B. Gastricacid

C. Histamine

D. Serotonin

E. Noneoftheabove

33.A44-year-oldwomanisknowntohaveaorticcoarctationandrefusedcorrectivesurgerymanyyearsago.WhatabnormalitymightbefoundonachestX-ray?

A. Agrosslyenlargedheart

B. Anenlargedaorticknuckle

C. Largebilateralpleuraleffusions

D. Ribnotching

E. Noabnormality

34.Which of the following is an α1-receptor blocker that directly antagonizes sympathetic control ofvasculartone?

A. Diazoxide

B. Doxazosin

C. Methyldopa

D. Minoxidil

E. Ramipril

35.Thelossofelasticitywithageinwhichvesseltypecanleadtoanincreaseinsystolicbloodpressure?

A. Arteriole

B. Artery

C. Capillary

D. Vein

E. Venule

36.WhichofthefollowingdrugsisaglycoproteinIIb/IIIareceptorantagonist?

A. Aspirin

B. Clopidogrel

C. Dipyridamole

D. Epoprostenol

E. Tirofiban

37.Whichpulseisfoundbehindtheknee?

A. Brachial

B. Carotid

C. Femoral

D. Popliteal

E. Radial

38.Whichofthefollowinggivesgoodanalgesiaasthefirst-linetreatmentofcolickyabdominalpain?

A. Diamorphine

B. Fentanyl

C. Hyoscine

D. Morphine

E. Tramadol

39.Whichofthefollowingisnotabranchoftheinternalpudendalartery?

A. Deeparteryoftheclitoris/penis

B. Dorsalarteryoftheclitoris/penis

C. Inferiorrectalartery

D. Perinealarteries

E. Superiorglutealartery

40.Whatisthetotalvolumeofcerebrospinalfluid?

A. 15mL

B. 50mL

C. 150mL

D. 500mL

E. 1000mL

41.Whichoneofthefollowingoptionsistrueregardingtheanatomyofthefourthventricle?

A. ConnectedtothelateralventriclesviatheforaminaofLuschka

B. ConnectedtothethirdventricleviatheforamenofMagendie

C. Locatedinthemidbrain

D. Locatedintheponsanteriortothecerebellum

E. Medialtothethalamus

42.Duringthefirsttrimesterofpregnancy,whathappenstothecardiacoutput?

A. Decreasesby10%–15%

B. Decreasesby30%–40%

C. Increasesby10%–15%

D. Increasesby30%–40%

E. Remainsunchanged

43.Whichofthefollowingisthemostcommonisolatedcongenitalheartdefect?

A. Atrialseptaldefect

B. Coarctationoftheaorta

C. Patentductusarteriosus

D. Tricuspidatresia

E. Ventricularseptaldefect

44.Whereiscerebrospinalfluidproduced?

A. Arachnoidvilli

B. Choroidplexus

C. ForaminaofLuschka

D. Spinalcord

E. Subarachnoidspace

45.Whichoneofthefollowingfactorsmakedirectcurrentcardioversionlesslikelytobesuccessful?

A. Alcohol-inducedatrialfibrillationinayoungpatient

B. Atrialflutter

C. Enlargedleftatrium

D. Shortdurationsinceonset

E. Underlyinginfection

46.WhatdoestheQ-waveonanECGrepresent?

A. Atrialdepolarization

B. Atrialrepolarization

C. DepolarizationatthebundleofHis

D. RepolarizationatthebundleofHis

E. Ventricularrepolarization

47.Whichofthefollowingisthesiteofabsorptionofcerebrospinalfluid?

A. Arachnoidvilli

B. Choroidplexus

C. ForaminaofLuschka

D. Spinalcord

E. Subarachnoidspace

48.Whichofthefollowingcranialnerves(CN)isresponsibleforfacialsensation?

A. CNII

B. CNIII

C. CNIV

D. CNV

E. CNIX

49. Which of the following is the branch of the superior mesenteric artery that gives rise to theappendicealartery?

A. Ileocolicartery

B. Leftcolicartery

C. MarginalarteryofDrummond

D. Middlecolicartery

E. Rightcolicartery

50.Whichoneofthefollowingstatementsregardingtheprocessofnecrosisiscorrect?

A. Failureofnecrosiscanleadtomalignanttumourgrowth.

B. Necrosisisacomponentofnormalcellgrowthanddevelopment.

C. Necrosis is a tightly regulated, active process which prevents cell proliferation and malignanttumourgrowth.

D. Necrosisisaccidentalcelldeathwhichresultsintheswellingofcellsandorganelles,andultimatelycelllysis.

E. Necrosiswasfirstdiscoveredasanormalcomponentofdevelopingembryos.

AnswersPaper91.C–PepsinogenGastric chief cells secrete pepsinogen, gastric lipase and rennin. Gastrin and secretin stimulate thesecretionofpepsinogen.Theyworkinrelationtoparietalcellsintheconversionofpepsinogentopepsin.Chiefcellscontainahighconcentrationofroughendoplasmicreticulum.

2.B–DehydrationAcuterenalfailurecanbedividedintothreetypes:pre-renal,intrinsicandpost-renal.Pre-renalfailureiscausedby impairedperfusionof the kidneys.Thismaybe secondary to heart failure (causing reducedcardiac output and hypotension) or caused by hypovolaemia, secondary to dehydration or severehaemorrhage. Intrinsic renal failure occurs when there is a damage to the kidney itself, e.g.glomerulonephritis. Nephrotoxic drugs (e.g. gentamicin) can cause tubular necrosis, which results inintrinsicrenalfailure.Finally,post-renalfailureresultsfromobstructionoftheurinarysystemdistaltotherenalcalyces(e.g.renalcalculi,benignprostatichyperplasia,stricturesortumours).

3.C–InterstitialfluidhasahigherproteincontentthanplasmaBodywatermakesup approximately60%ofbodyweight and is divided into extracellular (20%)andintracellularcompartments(40%).Extracellularfluidissplitintointerstitialfluidandplasma,whichareseparated only by the thin, permeable capillary membrane. The larger plasma proteins cannot passthrough this membrane, thus plasma protein content is higher than that of the interstitial fluid. Theelectrolyte composition of the extracellular and intracellular compartments is usuallywellmaintained.Theosmoticgradientbetweenthe twocompartmentscontrols thedistributionoffluidbetweenthe two.Sodium concentrations are higher in the extracellular fluid (approximately 139–145 mmol/L), whilepotassium is higher intracellularly (approximately 140 mmol/L, compared with 3.6–5 mmol/Lextracellularly).

4.C–CardiaAzymogenisaninactiveenzymeprecursor.Pepsinogenisanexampleofthisandrequiresabiochemicalchangetoaltertheconfigurationandrevealtheactivesiteoftheenzyme.Pepsinogenisactivatedbythehydrochloricacidreleasedfromparietalcells.Theautocatalyticreactionwhichensuesproducespepsin,whichactsuponthecarbonbondsofaromaticaminoacids.

5.A–CephalicphaseThecephalicphaseistheconditionedphasewherefoodisthoughtabout,smeltandtasted.Thisstimulatesthe vagus nerve and leads to the release of acetylcholine, resulting in histamine release. Histaminestimulatesthereleaseofgastrinandthisleadstotheproductionofgastricacid.Whenfoodarrivesinthestomach, stretch receptors and chemoreceptors are stimulated. This is the second (gastric) phase.Somatostatin is released to lower thepH.The third is the intestinalphase,wherefats in theduodenumleadtothereleaseofcholecystokinin(CCK)andgastricinhibitorypeptide.CCKstimulateschiefcellstoreleasepepsinogenandgastricinhibitorypolypeptide(GIP)inhibitsacidproduction.

6.E–Rightcoronaryartery

The right coronary artery (RCA) supplies the sinoatrial node (SAN) in 60%of individuals.Theother40%derivethebloodsupplytotheSANfromtheleftcircumflexartery.OcclusionoftheRCAresultsininferiorischaemicchangesonelectrocardiography.ThisisbecausetheRCAprovidesbloodsupplytotherightventriclewhichformsmostoftheinferiorborderoftheheard.ArrhythmiasmayariseiftheSANisinvolveddownstreamofanRCAocclusion.

7.E–Na+/K+/2Cl−co-transportinhibitionFurosemide isa loopdiureticfrequentlyused in themanagementofhypertension. It isalsoeffective intreating peripheral and pulmonary oedema, secondary to heart failure.Loop diuretics act by inhibitingchloridereabsorptionintheascendinglimboftheloopofHenle.Thisleadstonatriuresisand,becausewaterfollowssodium,diuresis.InhibitionoftheNa+/K+/2Cl−co-transportermeans thatpotassiumionsarealsoexcreted,whichcanleadtohypokalaemiaifpotassiumsupplementsarenotgiven.

8. E – The volume of water reabsorbed from the collecting duct depends on the presence ofantidiuretichormoneThe formation of urine begins with glomerular filtration. The glomerulus is a network of capillariesencapsulatedbyBowman’scapsule.AftertheglomerularfiltrateentersBowman’scapsule,itpassesintotheproximaltubule.Theproximaltubuleismadeupofcuboidalepitheliumwithanapicalmembraneofmicrovilli that increasesthesurfaceareaforreabsorption.Theactivetransportofsodiumunderliesthereabsorption of other solutes, including amino acids, glucose and electrolytes. Electrolytes such aspotassium and hydrogen ions are actively secreted into the tubule. Distal to the proximal tubule, thefiltrate enters the descending limb of the loop of Henle. This portion of the renal tubule is highlypermeabletowater,causingwatertomoveoutandintothehyperosmoticinterstitium.Theascendinglimbisrelativelyimpermeabletowaterandsoitremainsinthetubule,whilesodium,chlorideandpotassiumionsarereabsorbed.Thisresultsinhypotonictubularfluid.Activetransportofsodiumandchlorideintotheinterstitiumcreatesahyperosmolarmedullaryinterstitium.Thepermeabilityofthelatedistal tubuleand collecting duct is dependent on the secretion of antidiuretic hormone (ADH). This allows tighthypothalamic–pituitarycontrolofextracellularfluidosmolarity.

9.D–PatentductusarteriosusThisisarelativelytypicalpresentationofapatentductusarteriosus(PDA).ThemajorityofchildrenwithaPDAareasymptomatic,andthe‘machine-likemurmur’ispickedupasanincidentalfinding.Innormalphysiology, the ductus arteriosus closes in the firstmonth after birth but is likely to remain patent forlongerinprematurebabies.Prostaglandinreleaseisthoughttokeeptheductpatent,andpharmacologicalclosurecansometimesbeachievedwithadministrationoftheNSAIDindomethacin.

10.C–ItconvertsangiotensinogentoangiotensinITherenin–angiotensin–aldosterone(RAA)axisplaysavitalroleintheregulationofbloodpressureandfluid balance. Angiotensinogen is converted to angiotensin I by renin, which is secreted by thejuxtaglomerularapparatusofthekidneyinresponsetoreducedperfusion.AngiotensinIIisformedfromangiotensinIbyangiotensinconvertingenzyme(ACE).AngiotensinIIworkstoincreasebloodpressureby promoting vasoconstriction and aldosterone secretion from the adrenal cortex. Together, these twohormones increase reabsorption of sodium andwater, thus increasing blood volume and raising bloodpressure.ManyantihypertensivesactonthissystemandreducebloodpressurebyinhibitingtheRAAaxisat various stages. For example, ramipril and enalapril inhibit ACE, while spironolactone inhibitsaldosterone.AngiotensinIIreceptorblockers(e.g.losartan)canalsobeusedtoblocktheRAApathwayinthemanagementofhypertension.

11.E–TransitionalcellcarcinomaPainless haematuria is a common presentation of bladder malignancy. Predisposing factors includeoccupationinthedyeindustry(exposuretobenzidineandα-naphthylamine),smokinganddrugs,suchascyclophosphamide.Over90%ofbladdercancersareoftransitionalcellorigin.

12.A–GastricacidParietalcellsproducegastric(hydrochloric)acidinresponsetohistamine,acetylcholineandgastrin.Thecells themselves contain canaliculi from which gastric acid is secreted by active transport into thestomach. (Note that this concentration gradient is the steepest in the human body.) They also produceintrinsicfactorwhichisrequiredfortheabsorptionofvitaminB12.

13.D–ParietalcellsParietal cells produce gastric acid in response to histamine, acetylcholine and gastrin. The cellsthemselves contain canaliculi fromwhichgastric acid is secretedbyactive transport into the stomach.TheyalsoproduceintrinsicfactorwhichisrequiredfortheabsorptionofvitaminB12.

14.D–PregnancyPlasmaureaandcreatinineriseinresponsetoareductionintheglomerularfiltrationrate(GFR),whichmaybecausedbydamageoftheglomeruliorpoorrenalperfusion.UreaandcreatininedonotriseabovethenormalrangeuntilGFRdeclinesbyapproximately50–60%.Increasedproductionofureaoccurswithahigh-proteindiet, increasedmusclemassandcatabolic states (e.g. cancer, surgeryor trauma).Uppergastrointestinalbleedingalsocausesanincreaseinureabecauseofabsorptionandbreakdownofbloodproteinsreleasedintothegut.GFRusuallyincreasesinpregnancy(byupto50%),whichtendstolowertheconcentrationofplasmaurea.

15.E–StimulationoftheinnateimmuneresponseThe kidney boasts a plethora of homeostatic functions. These include the control of fluid balance,osmolarityandbloodpressure,theregulationofelectrolyteconcentrationandacid–basebalance,andtheeliminationofmetabolicwasteandtoxins.Thekidneysalsoplayaroleinerythrocyteproduction,viathesecretion of erythropoietin. Severe renal disease can therefore result in anaemia because of reducederythropoietin signalling to thebonemarrow.Counterintuitively, some renal conditions (e.g. polycystickidney disease) can result in polycythaemia. Osteomalacia can develop secondary to chronic renaldiseasebecauseofthereductioninvitaminDmetabolism.

16.D–ApoptosisrequiresATPasanenergysourceApoptosisistheprocessofgeneticallyprogrammedcelldeath,whichisessentialfornormalgrowthanddevelopment. It requires ATP, magnesium and calcium-dependent nuclease pathways to allow DNAbreakdownattheinter-histoneresidues.Caspase(cysteineaspartate-specificprotease)enzymesarethenactivated, which ultimately destroy nuclear DNA. Necrosis is another method of cell death, but it ispathologicalandcausesdisruptionofcellularphysiologyandresultsincelllysis.

17.B–150mLDeadspaceisthevolumeofgaswithintherespiratorysysteminwhichgasexchangedoesnotoccur.Inparticular, anatomical dead space refers to the dead spacewithin the conducting zones. In an averageadultthisis150mL.Alveolardeadspaceisthedeadspacewithintherespiratoryzonewherethealveolihaveinsufficientbloodsupplytopermitgasexchange.Inanon-diseasedlung,thisiszero.

18.B–HydrogenionsecretionoccursviaH+-ATPaseandNa+/H+co-transportersBodyfluidpHmustbemaintainedwithinaverynarrowrangeinordertooptimizeenzymaticfunction.Asmall deviation from the normal range can prove life-threatening. The kidneys play a vital role in themaintenance of acid–base balance. An acid–base disorder can result from respiratory or metabolicmeans.Forexample,respiratoryfailuresecondarytochronicobstructivepulmonarydiseasecanleadtoimpaired ventilation and CO2 retention. Increased arterial CO2 acidifies the blood as a result of theHenderson–Hasselbalchequation:

pH=pKa+log(HCO3−CO2)wherepKa=theaciddissociationconstant.

Increasing the concentrationofCO2 reduces theHCO3−:CO2 ratio, causing a reduction in pH (i.e.respiratoryacidosis).MetabolicacidosisoccurswhenthereisaprimarydecreaseinHCO3−.Examplesincludediabeticketoacidosis,lacticacidosisandseverediarrhoea.Renalcompensationtoanacid–basedisorderusuallytakes2–3days.ThekidneysminimizethepHdisturbanceinacidosisbyincreasingacidexcretionandHCO3−reabsorption.Innormalconditionsover99%ofthefilteredHCO3−isreabsorbed,mainlyintheproximaltubules.Intheproximaltubule,H+secretionoccursviaNa+/H+countertransport.In the late distal and collecting tubules,H+ ions are secreted by active transport, i.e. H+-ATPase.H+

secretioncanbeaugmentedtoincreasetubularH+concentrationbyasmuchas900-fold.

19.E–YoungerageofsubjectThe volume of anatomical dead space increaseswith age, so the younger the subject, the smaller thevolumeofdeadspace.Alloftheotherfactorsmentionedincreasethevolumeofdeadspace.

20.C–T-cellswithantigenreceptorsto‘self-antigens’aredestroyedbyapoptosisinthethymusCentral tolerance is theprocessbywhichself-reactiveT-cellprecursorsaredestroyedbyapoptosis inthe thymussoas topreventautoimmunereactionsagainstself-antigens.TheabilityofT-lymphocytes todistinguish self from foreign proteins is vital in fighting infection while preventing autoimmunedestruction.Self-reactivecellsaredestroyedbyprogrammedcelldeath(apoptosis).If toleranceis lostandan immunereaction tohostproteindevelops,autoimmunediseasecanresult.Suchconditionsoftendisplay a genetic trend, and an individual with autoimmune disease will often have more than onecondition.Autoimmunediseases includerheumatoidarthritis,vitiligo, typeIdiabetesmellitus,Addisondiseaseandperniciousanaemia.

21.E–ThereisasmalldeoxygenatedbloodsupplyincloserelationtothegaspermeablesurfaceForoptimalgasexchange, a largedeoxygenatedblood supply isneeded incloseapposition to thegaspermeablesurface tomaintainanoptimaldiffusiongradient.Gasexchange takesplaceprimarilyat thealveolarsurface.Itisassociatedwithmaintenanceoftheacid–basebalance.Theprocessofgasexchangeisfundamentallydependenton thedifferencebetweenatmosphericpressureand thepressurewithin thelungsthemselves.

22.B–500mLThetidalvolumeistheamountofairthatisbreathedinoroutduringnormalrespiration,whenthesubjectisatrest.Intheaveragehealthyindividual,thisisabout0.5L.

23.D–PortalveinTheportalvein is formedby theconfluenceof thesplenicand inferiormesentericveins.Thefledglingportal vein is then joined early in its course by the superiormesenteric vein. The portal vein carries

around75%oftheliver’sbloodsupply.

24.E–Totallungcapacityisaround4.8LintheaverageadultTotal lung capacity, the total volume of air in the lung aftermaximal inspiration, is around 6L in theaverageadult.Thevitalcapacityis4.8L.Vitalcapacityisthevolumeofairthatcanbeforciblyexpelled(maximalexpiration)aftermaximalinspiration.Itisthusthevolumeofairthat,atmaximaleffort,canbemovedinandoutofthelungundervoluntarycontrol.Theremainingvolumeofairiscalledtheresidualvolume(1.2L).

25.B–0.12–0.2secondsThenormalP–Rintervalisbetween0.12and0.2seconds,whichcorrespondsto3–5smallsquaresonanECG.TheQRScomplexshouldbe<0.12seconds,andtheQTintervalbetween0.38and0.42seconds.TheP–Rintervalrepresentsthetimetakenforatrialandpartoftheventriculardepolarizationtooccur.Atrialsystoleandventricularfillingoccurduringthistime.TheQRScomplexisextremelyimportant,asthisisthetimedelaycreatedbytheatrioventricularnodetoallowventricularfillingtooccur.

26.A–CysticarteryThecysticarteryisthemainarterialsupplytothegallbladder.ItisusuallyfoundinCalot’striangle,ananatomicalspacedefinedbythecysticduct,thecommonhepaticductandtheinferioraspectoftheliver.Proper isolation and division of the cystic artery is a crucial step in any operation to remove thegallbladder.

27.E–VentricularrepolarizationVentricular repolarization is represented on an ECG as the T wave. The P wave represents atrialdepolarizationandtheQRScomplexventriculardepolarization.AtrialrepolarizationisnotobservedonthenormalECG.Twavesgiveusinformationregardingthephysiologicalstatusoftheheart.Theycanbepathologicallyorphysiologicallyinverted.PathologicallyinvertedTwavesmayrepresentischaemiaorventricularhypertrophy.ItcanbenormaltohaveinvertedTwavesinleadsIII,aVRandV1.

28.E–NoneoftheaboveIntrinsic factor is producedbyparietal cells in the fundus andbodyof the stomach.AsB12 enters thestomachitbecomesboundtohaptocorrin.Thisglycoproteintravelstotheduodenumwherehaptocorrinisdigestedbypancreaticenzymes.B12canthenbindtointrinsicfactor.

29.C–RwaveTheRwavereflectsa rapiddepolarizationdown the intraventricularseptumtowards thecardiacapexjustbeforethedivisionintotheleftandrightbundlesdivide.TheRwavecanbeparticularlyinformativewith regard to the muscle bulk of the myocardium. Hypertrophic hearts have a larger mass and willthereforehavealargerelectricalcomplex.ItisimportanttotakethesizeoftheRwaveinthecontextofthepatient.Forexample,ayoung,slimpatientmayhavelargecomplexesonECGbutanormalecho.Thisisduetoareducedthoracicimpedance.

30.B–AtrialfibrillationwithgloballysmallcomplexesThis patient clearly suffers with chronic obstructive pulmonary disease, and has what is likely aninfectiveexacerbation.Herchestpainisthusrelatedtoinfection,andfurtherhistorywouldlikelyrevealapleuriticnature.Infectionisarelativelycommoncauseofatrialfibrillation.Thereasonthecomplexesaresmall isdue toan increased thoracic impedance fromemphysematous lungs.Othercausesof increased

thoracic impedance includeobesity,pleural effusionandpericardial effusion.SIQIIITIII is the textbookfindinginpulmonaryembolus(SwaveinleadI,QwaveinleadII,TinversioninleadIII),althoughsinustachycardiaismorecommonlyobservedinclinicalpractice.Electricalalternans–thealternationofQRScomplex amplitude between beats – occurs in cardiac tamponade. The normal JVP, temperature andproductivecoughwouldgoagainstthisdiagnosis.

31.A–AorticcoarctationThis patient has Turner syndrome,which can be associatedwith aortic coarctation. It is common thatpatientsarefoundtohaveadiscrepancyinthebloodpressurebetweenthearmsandlegs,withthebloodpressurebeinghigherinthearms.Dissectionofthethoracicaortaresultsinabloodpressuredifferencebetween the left and right arms. Aortic stenosis and congestive heart failure result in a narrow pulsepressure,whilemitralregurgitationusuallyhaslittleeffectonbloodpressure.

32.C–HistamineEnterochromaffin-like cells are exclusively found in the gastric mucosa. They are stimulated byacetylcholinetoproducehistamine.Histamineandgastrinacttogethertostimulategastricacidsecretion.The cells are foundwithin the antrum in the laminapropria.Enterochromaffin cells produce and store90%ofthebody’sstoreofserotonin.Serotoninactivatesbothsecretoryandperistalticreflexes.

33.D–RibnotchingRibnotchingrefers toanapparentdeformationof the inferiorandsuperior ribborderson imagingandoccursasaresultofdilatedintercostalcollaterals(whichhelpbloodbypassthecoarctationandsupplythe descending aorta). There is sparing of the first two ribs as the blood supply for these ribs is notderivedfromtheaorta.Ribnotchingincoarctationisusuallyapparentaftertheageof6–8years.Inthispatientwewouldfindanabsenceof the typicalaorticknuckle,andreplacementwithadoubleknuckle(made up of the dilated subclavian artery above and the post-stenotic dilatation of the aorta below).Cardiomegaly and pleural effusionswould be unlikely unless there is another underlying pathologicalprocess.

34.B–DoxazosinDoxazosinisanα1-blockeractingdirectlyonadrenergicreceptorstoreducevasculartone.Theyarealsoused inbenignprostatichypertrophy.NICEguidelines recommendanACE inhibitor (oranangiotensinreceptor blocker if intolerant) for individuals aged under 55 as the first-line treatment of essentialhypertension,andathiazidediureticoracalciumchannelblockerasthefirst-lineforindividualsaged55oroverorblackindividualsofanyage.Iffurthertreatmentisrequired,anACEinhibitorisadded(ifnotalreadyprescribed),oroneoftheothertwodrugtypesmentionedabove.OnlywhenapatientisalreadyonanACEinhibitor,thiazideandacalciumchannelblocker(orhasfailedtrialsofthesedrugs)shouldfourth-linedrugslikealpha-blockers,beta-blockersorfurtherdiuretictherapybeaddedin.Methyldopastimulatesα2-receptorsinthemedullainordertoreducesympatheticoutflow.MinoxidilisaK+channelactivator which is effective in resistant hypertension when combined with a loop diuretic and betablocker.

35.B–ArteryLossofelasticitygivingrisetoalossofcomplianceinthelargerarteriescanleadtoanisolatedriseinthesystolicbloodpressure.Theaffectedarteriescannotexpandtoaccommodatethehighbloodflowatthe end of ventricular contraction. This is usually associated with increasing age. NICE guidancerecommendstreatmentforallpatientswithBP≥160/100mmHg,andthedecisiontotreatforthosewith

BP≥140/90mmHgisdependentonendorgandamage,thepresenceofdiabetesmellitusandtheriskofcoronaryevents.

36.E–TirofibanPlateletaggregationisthoughttobeginwithaninjurytoavesselwallexposingthrombogenicvesselwallcollagen, to which platelets directly adhere. Activation of adherent platelets leads to synthesis of anumberofchemicalmediators–crucialamong these isarachidonicacidand thromboxaneA2.Aspirinactshere as an irreversible inhibitorof cyclooxygenase, and thus an inhibitor of arachidonic acid andthromboxaneA2 synthesis.Crucially, inhibitionof cyclooxygenases in thevascular endotheliumwouldlead toapro-coagulanteffectbutas thesecells,unlikeplatelets,arenucleated,cyclooxygenasecanberegenerated. Thromboxane A2 leads to platelet expression of glycoprotein (GP) IIb/IIIa receptors,subsequentbindingoffibrinogenandplateletaggregation.TheexpressionofGPIIb/IIIareceptorsisADP-dependent and thus their expression can be inhibited by the ADP receptor antagonist clopidogrel oradenosinere-uptakeinhibitorssuchasdipyridamole.GPIIb/IIIaantagonists,liketirofiban,actsubsequenttoGPIIb/IIIa expression to inhibit platelet aggregation. Parenteral prostacyclins suppress the action ofmediatorslikethromboxaneA2.

37.D–PoplitealThepoplitealarteryisacontinuationofthefemoralarteryandsubsequentlygivesrisetotheanteriorandposterior tibial arteries. It is palpable in the popliteal fossa. There is a clinical association betweenaortic aneurysms and popliteal aneurysms, and so if a popliteal artery is felt to be aneurismal,examinationoftheabdomenisindicated.

38.C–HyoscineHyoscine is an antispasmodic and is often used to relieve colicky abdominal pain. However, it iscontraindicatedinparalyticileus,glaucomaandinpatientswithmyastheniagravis.Side-effectsincludedrymouth,constipationandurinaryretention.

39.E–SuperiorglutealarteryThesuperiorglutealarteryisabranchoftheinternaliliacartery.Theinternalpudendalarteryisabranchoftheinternaliliacarterythatsuppliesbloodtotheexternalgenitalia.

40.C–150mLCerebrospinalfluidliesinthesubarachnoidspace.Thetotalvolumeisapproximately130–150mL.Thisvolumeissplitbetweentheventriclesofthebrain(50mL)andthespinalcord(100mL).

41.D–LocatedintheponsanteriortothecerebellumThefourthventricleisoneofthecerebrospinalfluid(CSF)-filledcavitieswithinthebrain.Itissituatedin the pons/uppermedulla anterior to the cerebellum. It receivesCSF from the third ventricle via thecerebralaqueductinthemidbrain.ThefourthventricledrainsintothesubarachnoidspaceviathemedialforamenofMagendie(MformedialandMagendie)andthetwolateralforaminaofLuschka(LforlateralandLuschka).

42.D–Increasesby30–40%Pregnancyisassociatedwithanumberofdramaticphysiologicalchanges.Inthefirst trimester,cardiacoutputincreasesby30–40%.ThissteadyrisecanbedemonstratedonDopplerechocardiography,aswellasuptoa15%increaseinheartrate.Thereisalsoasteadyreductioninsystemicvascularresistance.

43.E–VentricularseptaldefectVentricularseptaldefects(VSDs)occurin2per1000births.Theycaneitheroccurinisolationoraspartofamorecomplexlesionincombinationwithothercongenitalcardiacdefects.Apansystolicmurmurattheleftsternaledgemaybeheard.ThesizeoftheVSDhasabearingonthepresentationofsymptoms.LargeVSDscanresult inheartfailureininfancywithtachypnoea,failuretothrive,feedingdifficulties,hepatomegalyandintercostalrecession.Spontaneousclosureoccursin30–50%ofVSDs.

44.B–ChoroidplexusCerebrospinalfluid(CSF)isfoundinthesubarachnoidspace.Itisproducedinthechoroidplexusofthelateral,thirdandfourthventricles.ItflowsthroughtheventriclesofthebrainandpassesfromthefourthventricleintothesubarachnoidspaceviathetwolateralforaminaofLuschkaandthemedialforamenofMagendie.

45.C–EnlargedleftatriumAleftatrialsizegreaterthan5cm2makesDC(directcurrent)cardioversionextremelydifficult.Mitralstenosis can result in an extremely enlarged left atrium,makingDC cardioversion almost impossible.Atrial flutter is a macro re-entry circuit and is easily terminated by DC cardioversion. Patients withunderlying infection should generally have rate control and treatment of the underlying cause. Youngpatientswithalcohol-inducedatrialfibrillation(AF)areoftencandidatesforthe‘pillinpocket’regimen(whereasingleoraldoseofananti-arrhythmiccanbetakenbyapatientatthetimeandplaceofonsetofAF).

46.C–DepolarizationatthebundleofHisTheQwaveonanECGshouldberelativelysmall(unlessitispathological),asthemusclebulkissmall.It isrepresentativeofdepolarizationat thebundleofHis.Aso-called‘pathologicalQwave’occursinfullthickness(transmural)myocardialinfarcts.Theresultofthefullthicknessinfarctisanon-conducting‘window’ of myocardium with no electrical activity. The Q wave is essentially looking through thiswindowatthedepolarizationoccurringontheothersideoftheheart.

47.A–ArachnoidvilliCerebrospinalfluidisabsorbedbythearachnoidvilliintothevenouscirculation.Thesearefinger-likeprojectionsintothesubarachnoidspace.ObstructionofCSFflowcanresultinhydrocephalus.

48.D–CNVThe trigeminal nerve (CN V) is responsible for facial sensation. It has three divisions: ophthalmic,maxillaryandmandibular.Theuppersensoryborderofthetrigeminalnerveisbetweentheearandskullvertex.Thelowersensoryborderisabovetheangleofthejaw.

49.A–IleocolicarteryTheileocolicarteryisthelowestofthethreecolicarteriesarisingfromthesuperiormesentericartery.Itgivesofftheappendicealarterywhichisligatedduringappendectomy.

50.D–Necrosis isaccidentalcelldeathwhichresults in the swellingofcellsandorganelles,andultimatelycelllysisNecrosisisapathologicalprocessthatresultsinuncontrolledcelldeathcausedbyanextrinsicstimulus.It can be inducedby acute injury, hypoxia, viruses or drugs and results in swelling of the cell and itsorganelles, vacuolization and lysis. Macrophages phagocytose the debris, which in turn initiates an

inflammatoryresponse.Necrosismustbedifferentiatedfromapoptosis.Apoptosisisafunctionofnormalhealthanddevelopmentwherebycelldeathoccursinaregulatedandcontrolledmanner.

QuestionsPaper101.Thedorsalcolumn–mediallemniscuspathwaytransmitswhichsensoryinformation?

A. Crudetouch

B. Itch

C. Pain

D. Proprioception

E. Temperature

2.Thesubarachnoidspaceendsatwhichlevel?

A. C1

B. L4

C. S2

D. T1

E. T11

3.Whichofthefollowingdoesthenasalmucosainclude?

A. Laminapropria

B. Pseudostratifiedciliatedcolumnarepithelium

C. Seromucousglands

D. Vascularplexus

E. Alloftheabove

4.Whichofthetonsilsislinedwithciliatedpseudostratifiedcolumnarepithelium?

A. Lingualtonsil

B. Palatinetonsil

C. Pharyngealtonsil

D. Tubaltonsil

E. Noneoftheabove

5.Towhichdermatomalleveldoesthenipplecorrespond?

A. C8

B. T1

C. T2

D. T3

E. T4

6.Whichoneofthefollowingstatementsaboutreniniscorrect?

A. IncreasedabsorptionofNa+andCl−increasesreninsecretion.

B. Reninisasteroidhormone.

C. Reninissecretedbythemaculadensawithinthejuxtaglomerularapparatus.

D. Therateofreninsecretionisdecreasedinresponsetoincreasedrenalarterialbloodpressure.

E. Therateofreninsecretionisincreasedbyparasympatheticstimulationofrenalnerves.

7.Whichofthefollowingstatementsregardingrefeedingsyndromeisnotcorrect?

A. Alcoholic patients and those with malignancy are among those at high risk of developing thesyndrome.

B. Clinicalfeaturesincluderhabdomyolysis,arrhythmiasandrespiratoryandcardiacfailure.

C. Clinicalfeaturesoccuratserumphosphatelevelsoflessthan0.5mmol/L.

D. Itcanbepreventedbylowcaloricintroductionoffeeds.

E. Refeedingsyndromeisnotseenwhenthepatientisfedviaparenteralnutrition.

8.Withreferencetothecorticospinaltract,whatpercentageoffibresdonotdecussateanddescendintheipsilateraltract?

A. 5%

B. 10%

C. 15%

D. 20%

E. 25%

9.Whichoneofthefollowingislinedwithstratifiedcolumnarepithelium?

A. Bloodvessels

B. Ductsofthesubmandibularglands

C. Largeintestine

D. Oesophagus

E. Smallintestine

10.Whichofthefollowingstatementsisnottrueinrelationtoepithelialtissue?

A. Epithelialcellsareattachedtooneanother.

B. Epithelialcellsareseparatedfromtheunderlyingtissuebyabasementmembrane.

C. Epithelialtissuecoverssurfaceswithanuninterruptedlayerofcells.

D. Epithelialtissueisnon-polarized.

E. Theintracellularspacebetweenepithelialcellsissmall.

11.Whichoneofthefollowingislinedwithstratifiedkeratinizedsquamousepithelium?

A. AnusbelowHilton’swhiteline

B. Bladder

C. Bloodvessels

D. Ductsofthesubmandibularglands

E. Oesophagus

12.Whichofthefollowingstatementsaboutactionpotentialsisnotcorrect?

A. ActionpotentialsarecausedbyasuddenopeningofvoltagegatedNa+channels.

B. Actionpotentialsareunidirectional.

C. Actionpotentialsobeythe‘all-or-nothing’response.

D. Actionpotentialsrequireathresholdpotentialtobereachedbeforeinitiation.

E. The strength of impulse gradually diminishes as the potential travels further from the source ofinitiation.

13.Therespiratorysegmentofthenasalcavityislinedwithwhichepithelium?

A. Ciliatedpseudostratifiedcolumnar

B. Ciliatedstratifiedcolumnar

C. Simplecolumnar

D. Simplesquamous

E. Stratifiedsquamous

14.Whichextraocularmuscleissuppliedbythetrochlearnerve?

A. Inferioroblique

B. Lateralrectus

C. Medialrectus

D. Superioroblique

E. Superiorrectus

15.Whichcranialnerveisprimarilyresponsibleforeyeabduction?

A. Abducensnerve

B. Facialnerve

C. Oculomotornerve

D. Opticnerve

E. Trigeminalnerve

16.Whatmovementsofthelarynxdothecricothyroidmusclesproduce?

A. Theyabductandexternallyrotatethearytenoidcartilageswhichabductthevocalfolds.

B. Theyadductandinternallyrotatethearytenoidcartilageswhichadductthevocalfolds.

C. Theylengthenandstretchthevocalfolds.

D. Theynarrowthelaryngealinletbydecreasingthedistancebetweenthearytenoidcartilagesandtheepiglottis.

E. Noneoftheabove.

17.Osmolalityoftheextracellularfluidisaffectedbyanumberofcomponents.Whichoneofthesedoesnotsignificantlycontributetoosmolality?

A. Glucose

B. K+

C. Na+

D. Plasmaproteins

E. Urea

18.Whichoftheturbinates(nasalconchae)arethelargest?

A. Inferiorturbinates

B. Middleturbinates

C. Outerturbinates

D. Superiorturbinates

E. Noneoftheabove

19.Whichoneofthefollowingislinedwithstratifiednon-keratinizedsquamousepithelium?

A. AnusbelowHilton’swhiteline

B. Bladder

C. Bloodvessels

D. Ductsofthesubmandibularglands

E. Oesophagus

20.Whichcranialnerveinnervatesallthreenasalturbinates?

A. I

B. II

C. V

D. VII

E. VIII

21.Whichofthefollowingisalwayspatent?

A. Laryngopharynx

B. Nasopharynx

C. Oropharynx

D. Alloftheabove

E. Noneoftheabove

22.Whyareactionpotentialsunidirectionalwithinneurons?

A. Axonalpropagationofelectricalactivitycanonlyoccurinonedirection.

B. Consumptionofadenosinetriphosphatepreventsbidirectionalpropagation.

C. Na+channelsbehind theactionpotentialbecomerefractory,andsoareunable todepolarizeagainimmediately.

D. Na+ionstraveldowntheirconcentrationgradientalongtheaxon.

E. Recruitedvoltage-gatedCa2+channelsopenmoreslowly,preventingreverseddepolarization.

23.Whichoneofthefollowingnervefibretypesisnotmyelinated?

A. TypeAalpha

B. TypeAdelta

C. TypeAgamma

D. TypeB

E. TypeC

24.Fromwhichofthefollowingistheepidermisderived?

A. Ectoderm

B. Endoderm

C. Mesoderm

D. Alloftheabove

E. Noneoftheabove

25.Whichisthelargestoftheparanasalsinuses?

A. Ethmoidaircells

B. Frontalsinus

C. Maxillarysinus

D. Sphenoidalsinus

E. Noneoftheabove

26.Whichofthefollowingcorrectlydescribestheseriesofeventsthatmakeupthereflexarcofakneejerk?

A. Stretchof tendon andmuscle; detectedby afferent sensoryneuronwithinmuscle spindle; synapsewithinterneuronindorsalrootganglion;synapsewithmotorneuroninventralhorn;motorefferenttomuscleendplate;contractionofmuscle

B. Stretchof tendon andmuscle; detectedby afferent sensoryneuronwithinmuscle spindle; synapsewithmotorneuronindorsalhorn;motorefferenttomotorendplate;contractionofmuscle.

C. Stretchof tendon andmuscle; detectedby afferent sensoryneuronwithinmuscle spindle; synapsewithmotorneuronindorsalrootganglion;motorefferenttomotorendplate;contractionofmuscle

D. Stretchof tendon andmuscle; detectedby efferent sensoryneuronwithinmuscle spindle; synapsewithmotorneuroninventralhorn;motorafferenttomotorendplate;contractionofmuscle

E. Stretchof tendon andmuscle; detectedby afferent sensoryneuronwithinmuscle spindle; synapsewithmotorneuroninventralhorn;motorefferenttomuscleendplate;contractionofmuscle

27.Whichoneofthefollowingneurotransmittersisreleasedatthesynapticjunctionsofmotorfibres?

A. Acetylcholine

B. Glutamate

C. Noradrenaline

D. Serotonin

E. SubstanceP

28.Whichistheonlylaryngealmuscleinnervatedbytheexternalbranchofthesuperiorlaryngealnerve?

A. Cricothyroid

B. Lateralcricoarytenoid

C. Posteriorcricoarytenoid

D. Sternothyroid

E. Thyroarytenoid

29.Whichcellsareresponsibleformaintainingtheclarityofthecornea?

A. Columnarcells

B. Cones

C. Endothelialcells

D. Epithelialcells

E. Squamouscells

30.Thesuperiorandrecurrentlaryngealnervesarebranchesofwhichcranialnerve?

A. VII

B. IX

C. X

D. XI

E. XII

31.Whichoneofthefollowingstatementsaboutacetylcholine(ACh)iscorrect?

A. AChbindssolelywithnicotinicreceptors.

B. AChissynthesizedfromtyrosine.

C. AChistheprincipalexcitatoryneurotransmitterwithinthecentralnervoussystem.

D. AcetylcholinesterasecatalysesthebreakdownofAChintocholineandacetyl-CoA.

E. MyastheniagravisdescribesadiseaseinwhichantibodiesareformedagainstAChreceptorsattheneuromuscularjunction.

32.Anelderlypatientisfoundtobehyponatraemic.Whichofthefollowingtestswouldyourequestnext?

A. ChestX-ray

B. Plasmaosmolality,urinarysodiumandosmolality

C. Shortsynacthentest

D. Thyroidfunctiontests

E. UrgentECG

33.WhatdoestroponinTbindto?

A. Actin

B. Actinin

C. Calcium

D. Myosin

E. Tropomyosin

34.Whichoneofthefollowingactstoinhibitthesecretionofvasopressin?

A. Alcohol

B. AngiotensinII

C. MDMA

D. Nausea

E. Stress,includingpain

35.Whatisthemajorriskofrapidlyrehydratingapatientfollowingprolongeddehydration?

A. Cerebraloedema

B. Excessivelossofelectrolytesviatheurine

C. Hyperkalaemia

D. Pulmonaryoedema

E. Refeedingsyndrome

36.Whichoneofthefollowingstatementsistrueaboutcellswithinthenervoussystem?

A. Degenerationofaxonscannotoccurafterbirth.

B. Motorfibreshavetheircellbodieswithindorsalrootganglia.

C. Sensoryfibreshavetheircellbodieswithintheventralhornorthebrain.

D. Theendoneuriumismadeupofmyelin.

E. Theyarederivedfromtheectoderm.

37. Local anaesthetics block the sensation of pain.Which one of the following is true regarding theirmechanismofaction?

A. TheyinhibittheNa+/K+ATPasepump.

B. Theyinhibittheopeningofvoltage-gatedNa+channels.

C. Theyreducethethresholdpotentialforactionpotentialgeneration.

D. TheystimulatetheNa+/K+ATPasepump.

E. Theystimulatetheopeningofvoltage-gatedK+channels.

38.WhichofthefollowingstatementsregardingNa+homeostasisisnotcorrect?

A. Aldosterone increases Na+−K+ ATPase activity within principal cells, but has no effect uponepithelialNa+channels.

B. AlmostallNa+excretionoccurswithinthekidney.

C. Na+ excretion is dependent upon extracellular fluid volume and osmolality because Na+concentrationisthemaindeterminingfactorforbothofthese.

D. ReabsorptionofNa+occursthroughoutthewholerenaltubule,butismostimportantwithinprincipalcells.

E. The need for Na+ excretion is primarily detected via stretch receptors, receptors within thehypothalamusandmaculadensa,andthebaroreceptors.

39.Whichofthefollowingisnotacauseofincreasedinterstitialfluidvolume?

A. Decreasedplasmaproteinlevels

B. Increasedcapillarypermeabilitycaused,forexample,byhistamine,substancePandkinins

C. Increasedprecapillaryconstriction

D. Prolongedstanding

E. RetentionofNa+andwaterwithinextracellularfluid

40.Whichcellsareresponsibleforthesmoothandregularsurfaceofthecornea?

A. Columnarcells

B. Cones

C. Endothelialcells

D. Epithelialcells

E. Squamouscells

41.Whichcranialnervesuppliestheupperlidoftheeye?

A. Abducensnerve

B. Facialnerve

C. Oculomotornerve

D. Opticnerve

E. Trigeminalnerve

42. Which of the following combinations of symptoms and signs could be consistent with aspirinoverdose?

A. Respiratorydepression,otalgia,headache,nauseaandvomiting,renalfailure

B. Respiratorydepression,pinpointpupils,drowsinessandreducedGlasgowcomascore

C. Tinnitus,respiratorydepression,respiratoryacidosis,vertigo,hyperthermia

D. Tinnitus,vertigo,arrhythmias,hyperventilation,respiratoryalkalosis,hyperthermia

E. Tinnitus,vertigo,hyperventilation,nauseaandvomiting,metabolicacidosis,respiratoryalkalosis

43.A36-year-oldwomanhas rheumatoidarthritisandhasbeenonmethotrexate for thepast3months.Her joint pain and inflammation have worsened over the past few weeks and her rheumatologistprescribed ibuprofen and omeprazole 10 days ago. She visits her GP, as her pain has largelyresponded but her joint inflammation remains unchanged.What is the most appropriate course ofaction?

A. Keepheronhercurrentmedicationandreviewin2weeks’time

B. Referhertoadifferentrheumatologistforasecondopinion

C. Stopomeprazolebutcontinueibuprofen

D. SwitchibuprofentoanalternativeNSAIDandcontinuewithomeprazole

E. Switchibuprofentoparacetamolandcontinueomeprazole

44.A40-year-oldwomanhasbeenregularlytakinganon-steroidalanti-inflammatorydrug(NSAID)forthe past 6 weeks and has been experiencing diarrhoea, tiredness and shortness of breath duringexertion.Herfullbloodcountshowedhaemoglobin8.2g/dLandmeancellvolume104fL.Abloodfilmshowedreticulocytesandspherocytes.WhichNSAIDismostlikelyresponsiblefortheseside-effects?

A. Celecoxib

B. Fenbufen

C. Mefenamicacid

D. Piroxicam

E. Rofecoxib

45.Patientswithaspleniaaresusceptibletowhichofthefollowingpathogens?

A. Candidaalbicans,Entamoebahistolytica,Aspergillusflavus

B. Candidaalbicans,Haemophilusinfluenzae,Mycoplasmapneumoniae

C. Chlamydiatrachomatis,Yersiniaenterocolitica,Salmonellatyphi

D. Haemophilusinfluenzae,Neisseriameningitidis,Streptococcuspneumoniae

E. Neisseriameningitidis,Mycoplasmapneumoniae,Chlamydiapneumoniae

46.Selecttheclinicalscenariowhichismostlikelytobetheresultoflymphaticsystemdisease.

A. A7-year-oldboypresentswithrightkneeswelling,painandafeverandislimping.

B. A19-year-oldwomanpresentswithlipandtongueswelling,anewitchyrashandisshortofbreathafteringestingpeanuts.

C. A 20-year-oldman presentswith a swollen, tender, hot left leg two days after flying home fromAustralia.

D. A47-year-oldwomanwithknownbreastcancerpresentswithacute-onsetrightarmswelling.Thearmisnothotortender.

E. A79-year-oldwomanfellontoheroutstretchedrighthandandnowhasaswollentenderrightwrist.

47.Whichcommoncomplicationmayresultfromradioiodinetreatmentinhyperthyroidism?

A. Agranulocytosis

B. Goitre

C. Hypothyroidism

D. Myxoedemacoma

E. Thyroidstorm

48.WhatdoestroponinCbindto?

A. Actin

B. Actinin

C. Calcium

D. Myosin

E. Tropomyosin

49.Whatisthemembranepotentialofskeletalmuscle?

A. –80mV

B. +80mV

C. –90mV

D. +90mV

E. +95mV

50.Whatisthenameofthefive-carboncompoundthatisfoundinthetricyclicacidcycle?

A. Acetyl-CoA

B. Citrate

C. Oxaloacetate

D. Oxoglutarate

E. Succinate

AnswersPaper101.D–ProprioceptionThe dorsal column–medial lemniscus pathway transmits fine touch, vibration and proprioceptiveinformation.Thespinothalamictracttransmitsinformationaboutpain,temperature,itchandcrudetouch.

2.C–S2ThesubarachnoidspaceextendsfromthebasalcisternssurroundingthebrainstemsuperiorlytothelevelofS2.Itisthespacebetweenthearachnoidmembraneandpiamaterwhichisfilledwithcerebrospinalfluidandcontainsthelargebloodvesselsthatsupplythebrainandspinalcord.

3.E–AlloftheaboveThenasalpassagescontainthecellswhichareabletoconditionairbeforeitreachesthemoredelicatealveolar tissue. Each has a different function. The ciliated epithelium expels irritants, the seromucousglandsprovidemucousandthevascularplexusallowsforhumidificationandwarmingoftheinhaledair.

4.C–PharyngealtonsilThepharyngealtonsils(adenoids),whicharelocatedintheroofofthepharynx,arelinedwithrespiratoryepithelium,andbecauseofthistheyalsolackcrypts.Theyareamassoflymphoidtissuesituatedattheverybackofthenose.Othertonsilsareusuallylinedwithnon-keratinizedstratifiedsquamousepithelium.

5.E–T4The nipple corresponds to the level of the T4 dermatome. A dermatome is an area of skin which issupplied by a single spinal nerve. Identifying specific dermatomes is importantwhen assessing spinaltraumaandspecificlandmarkssuchasthenipple(mostlyhelpfulinthemales)aidindetermininglevelsofpathology.

6.D–TherateofreninsecretionisdecreasedinresponsetoincreasedrenalarterialbloodpressureThejuxtaglomerularapparatusiscomposedof(1)themaculadensaand(2)granularcellswithinthewalloftheafferentarteriole.Renin,aproteaseenzyme,issecretedbythegranularcells.Secretionofreninisincreased by sympathetic stimulation via renal nerves, circulating catecholamines and prostaglandins.Reninsecretionisinhibitedbyincreasedafferentarteriolarpressure,angiotensinII,vasopressinandtheabsorptionofNa+andCl−.TheconcentrationofNaClwithinthebloodissensedbythemaculadensa.

7.E–RefeedingsyndromeisnotseenwhenthepatientisfedviaparenteralnutritionRefeedingsyndromedescribes thecharacteristicmorbidityandmortality thatcanarisefromchanges inmetabolism caused by feeding after prolonged starvation. During periods of starvation, carbohydrateintakeisreducedandthereforeinsulinsecretionisalsoreduced.Themetabolismoffatandproteinduringthis time to produce energy depletes intracellular phosphate and other electrolytes. When eatingrecommences, insulin secretion is stimulated again and results in an increased uptake of phosphate bycells.This results in amarkedly reduced serumphosphate level.Bothparenteral and enteral routesoffeedingcancauserefeedingsyndrome.

8.A–5%About5%offibresremainuncrossedanddescendintheipsilateralcorticospinaltract.Atthepyramidaldecussation, 80% of the fibres pass in the lateral corticospinal tract and about 15% in the anteriorcorticospinaltract.

9.B–DuctsofthesubmandibularglandsTheductsofthesubmandibularglandsarelinedwithstratifiedcolumnarepithelium.Columnarcellslinetheapical layerand the lowercellsarecuboidal.Theybecomestratifiedas theyapproach theopeningintotheoralcavity.

10.D–Epithelialtissueisnon-polarizedEpithelialcellsdifferfromconnectivetissuebybeingpolarized.Theirapicalsurfaceisexposedandthebasalsurfaceliesontheunderlyingconnectivetissue.Polarizationallowsthecellstomaintainaspecificarrangement with respect to their intracellular organelles and the consequent directional transport ofmaterials.

11.A–AnusbelowHilton’swhitelineHilton’s white line is the boundary within the anal canal below which the lymphatics drain to thesuperficialinguinalnodes.Thislinerepresentsthetransitionbetweennon-keratinizedstratifiedsquamousepithelium (above) and keratinized stratified squamous epithelium (below). The keratinized squamousepithelium is important in areasof constant abrasion as the cells canbe replacedbefore thebasementmembraneisexposed.Keratinizationallowsthelayertobekepthydrated.

12.E–ThestrengthofimpulsegraduallydiminishesasthepotentialtravelsfurtherfromthesourceofinitiationTheinitiationofanactionpotentialisdependentupontheopeningofvoltagegated(orsensitive)sodiumion (Na+) channels. These channels are voltage gated, so that they will only open when the optimalthreshold of electrical balance has been reached, amembrane potential of around –55mV. Once thispotential is reached however, their opening creates a rapid influx of Na+ ions into the neuronal cell,resultinginarapiddepolarization.Theall-or-nothingresponsereferstothefactthatasmallerchangeinmembranepotentialbelowthethresholdwillnotinitiatearesponse,butoncethethresholdisreached,itinitiatesastandard‘one-size-fits-all’strengthofresponsethatpropagatesalongtheaxoninonedirectiononlyandremainsconsistentinitsimpulsestrengthirrespectiveofhowfartheimpulsetravels.

13.A–CiliatedpseudostratifiedcolumnarTherespiratorysegmentislinedwithciliatedpseudostratifiedcolumnarepithelium.Thisisincontrasttotheolfactorysegmentwhichislinedwithnon-ciliatedpseudostratifiedcolumnarepithelium.

14.D–SuperiorobliqueThe trochlear nerve is the fourth cranial nerve and supplies the superior obliquemuscle, thus causingintorsion (internal rotation), depression and abductionof the eye.The trochlearnerve leaves thebrainstemviathedorsalaspectanditdecussatesbeforereachingitstargetmuscle.Thefourthnerveisrarelyimpairedonitsown,butifitis,itisnormallysecondarytotrauma.

15.A–AbducensnerveThe abducens nerve (CN VI) supplies the lateral rectus, which causes the eye to abduct. Abductiondescribesthemovementoftheeyeawayfromthemedian(saggital)planeofthebody.Asixthnervepalsy

is implicated in much pathology including multiple sclerosis, a pontine stroke and Wernickeencephalopathy,anditcanbeafalselocalizingsignwithincreasedintracranialpressure.

16.C–TheylengthenandstretchthevocalfoldsThecricothyroidmusclesareabletolengthenandstretchthevocalfoldsbytiltingthethyroidcartilagelaminabackwards.Thisleadstohigherpitchphonation.Itistheonlylaryngealmuscleinnervatedbytheexternalbranchofthesuperiorlaryngealnerve.

17.B–K+

ThemainfactorsdeterminingplasmaandextracellularosmolalityaretheconcentrationsofNa+,ureaandglucose. Plasma proteins make only a small contribution, and K+, because it is predominantlyintracellular, has no appreciable contribution. If there is an increase in extracellular fluid, osmolalityoccurs as a result of a solute such as urea, because this diffuses readily across cell membranes (incomparisontoNa+).Theintracellularfluidosmolalitywillalsoincrease,andosmoreceptorswillnotbestimulated.

18.A–InferiorturbinatesThe inferior turbinates are the largest. They aremostly involved in humidifying, heating and directingairflow.Theyextendhorizontallyalongthelateralwallofthenasalcavityandtheyconsistofalaminaofspongybone.

19.E–OesophagusThe oesophagus is lined with non-keratinized squamous epithelium, which is important in areas ofconstantabrasionasthecellscanbereplacedbeforethebasementmembraneisexposed.

20.C–VAllthreeturbinatesareinnervatedbythefifth(trigeminal)nerve.Theyconveybothpainandtemperaturesensation. The first cranial nerve (olfactory) innervates primarily the superior turbinate and to someextentthemiddleturbinates.

21.B–NasopharynxThenasopharynxistheuppermostpartofthepharynx.Itextendsfromthebaseoftheskulltotheuppersurfaceofthesoftpalate.Italwaysremainspatent.Anteriorlyitcommunicatesthroughthechoanaewiththenasalcavities.

22.C–Na+channelsbehindtheactionpotentialbecomerefractory,andsoareunabletodepolarizeagainimmediatelyAftertheNa+channelopens,itrapidlybecomesrefractoryandwillnotreopenuntilthisrefractoryperiodhaspassed.Thisensuresthattheactionpotentialtravelsinonedirectionalongtheaxon.ThepresenceofNa+ionswithintheneurondoesresultinamorepositivecharge,andthiscausesincreasedopeningofthevoltage-sensitiveNa+ channels.However, theNa+ channelsdonotopenas a result of aNa+ chemicalconcentrationgradientalone.Axonsareabletopropagateelectricalactivityinbothdirections,asisseenwith localpotentials.Actionpotentialpropagationwithinneuronsdoesnot involveCa2+ ion channels,andconsumptionofATPdoesnotpreventbidirectionalpropagation.

23.B–TypeAdelta

Myelinationofnervefibresallowsmorerapidconductionofactionpotentialalongthefibre.AlltypesofAandBfibresaremyelinated,andsoareusedbynervesrelyinguponfastconductionofnerveimpulses.TypeCnervefibresareunmyelinated,andthereforeconductnerveimpulsesmoreslowly.

24.A–EctodermTheepidermisisderivedfromectoderm.Theectodermistheoutermostgermlayer.Itisthelayerwhichdifferentiates to form thenervoussystem, toothenamelandalso theepidermis. It iscomposedof threeparts:theexternalectoderm,theneuralcrestandtheneuraltube.Theendodermformstheliningofmostof the gastrointestinal tract (except that of the mouth, pharynx and lower rectum which are lined byectoderm)andotherorgans.Themesodermisabletodifferentiateintoanumberofdifferenttissues.

25.C–MaxillarysinusThemaxillarysinusisthelargestoftheparanasalsinuses.Theyaresituatedwithinthemaxillarybonesundertheeyes.Allthesinusesarelinedwithciliatedpseudostratifiedcolumnarepithelium.

26.E–Stretchoftendonandmuscle;detectedbyafferentsensoryneuronwithinmusclespindle;synapse with motor neuron in ventral horn; motor efferent to muscle end plate; contraction ofmuscleUndernormalcircumstances,stretchingatendonproducesreflexcontractionofmuscle.Thetypicalspinalreflex arc occurs as follows: the stretch of tendon andmuscle is detected by afferent sensory neuronswithin themuscle spindle; these synapsewithmotor neurons in the ventral horn, and thenwithmotorefferentstothemuscleendplate,resultingincontractionofmuscle.Ifapatienthassufferedastrokeorspinal injury proximal to where a reflex is tested, descending inhibition of the spinal reflex occurs,creatingbriskerreflexeswhentheyareexamined.

27.A–AcetylcholineAcetylcholine binds tomuscarinic and nicotinic receptors. Nicotinic receptors are ion-gated channelsfound within the motor end plate of neuromuscular junctions (NMJs). A propagated action potentialarriving at the presynaptic cleft of the NMJ facilitates the release of acetylcholine, which binds tonicotinic receptors, causingaconformationalchange toopen the ionchannel.Thisallows the influxofsodiumionsintothepostsynapticcleftanddepolarizationofT-tubules.

28.A–CricothyroidTheexternalbranchofthesuperiorlaryngealnervesuppliesthecricothyroidmuscle.Thisbranchisalsosusceptibletodamageduringthyroidectomyasitliesjustdeeptothesuperiorthyroidartery.

29.C–EndothelialcellsThecornealendothelialcellsarelowcuboidalorsquamouscellswhicharerichinmitochondria.Theyarecontinuouslypumpingoutfluidfromthetissuetomaintaintheclarityofthecornea,helpingtopreventsubsequent corneal oedema. These cells do not regenerate and instead stretch to compensate for deadcells.Thiscanhaveanimpactonfluidregulationwithinthecorneaandleadtoreducedtransparency.

30.C–XBoththesuperiorandrecurrentlaryngealnervesarebranchesofthevagusnerve(cranialnerveX).Thelaryngeal nerve is the first branch of the vagus nerve,which then divides to form the aforementionedbrancheswhichinnervatethelarynx.

31.E–MyastheniagravisdescribesadiseaseinwhichantibodiesareformedagainstAChreceptorsattheneuromuscularjunctionAcetyl-CoAandcholinecombinetoformACh,howeveracetylcholinesterasecatalysesthebreakdownofAChintocholineandacetate.AChistheneurotransmitterfoundattheneuromuscularjunctionswithintheskeletal muscle. Glutamate, by contrast, is an important excitatory neurotransmitter within the centralnervous system.ACh can bind to eithermuscarinic or nicotinic receptors.Noradrenaline, notACh, isformedfromtyrosine.

32.A–ChestX-rayAchestX-ray(tolookforapulmonarycauseof inappropriateantidiuretichormonesecretion;e.g. lungcancer,TB,pneumonia), short synacthen test (toexcludeAddisondisease)or thyroid function tests (torule out severe hypothyroidism)would all be appropriate testswhen investigating hyponatraemia.Themostuseful initial test, however, is todistinguishwhether the low sodium is causedby an increase insodiumexcretionorbyinappropriatewaterretention.Comparisonsbetweenurinaryandplasmasodiumandosmolalitywillhelptomakethesedistinctions.

33.E–TropomyosinThin myofilaments contain three different proteins: actin, troponin and tropomyosin. Actin is a long-stranded protein. Two alpha helix strands of actin proteins are twisted around each other to form adouble-stranded helix. Twisting around the groove between the two actin alpha helix strands lie twoalphahelixstrandsof tropomyosin,another long-strandedprotein.Tropomyosinblocksbindingsitesofmyosinintheactingroove.Alongthishelicalstructure,atregularintervals,aretroponinmolecules.Thetroponinmoleculesareattachedtoboththeactinandtropomyosinstrands.Troponinisatrimericproteinwiththreesubunits:troponinCbindstoCa2+ions;troponinTbindstotropomyosin;andtroponinIbindstoactin.

34.A–AlcoholAlcoholhasaninhibitoryeffectonvasopressinsecretion,explainingtheincreasedneedtomicturateandthe possibility of dehydration upon consumption.Angiotensin II released in response to hypovolaemiahelps to stimulate fluid retentionvia vasopressin release. Increased secretionof vasopressin and fluidretentionisoftenseeninpatientspostsurgeryasaresultofastressresponse.NauseaandingestionofMDMAalsostimulatevasopressinsecretion.

35.A–CerebraloedemaDuringperiodsofdehydration, thebrainsynthesizesosmolytes.Cerebraloedemacancomplicate rapidrehydration, because the intracellular concentrationofosmolyteshasbecomeabnormallyhigh and thusencourages excessive movement of water into cells. Refeeding syndrome describes the phenomenonencountered in malnourished patients when fat metabolism is rapidly converted to carbohydratemetabolism.Increasedsecretionofinsulincausesrapidcellularuptakeofphosphate,resultinginseverehypophosphataemia. The consequences of severe hypophosphataemia include rhabdomyolysis, acutehaemolyticanaemiaandfatalarrhythmias.

36.E–TheyarederivedfromtheectodermThe entire nervous system is of ectodermal origin. Peripheral nerve axons can regenerate, butregenerationofaxonsislimitedwithinthecentralnervoussystem.Sensoryfibreshavetheircellbodieswithindorsalrootgangliaorthebrain,andmotorfibrecellbodiesarelocatedwithintheventralhornof

thespinalcord.Sensoryandmotornervestraveltogetherwithinaperipheralnerve.Thesearewrappedwithinaconnectivetissuesheath,calledanendoneurium.

37.B–Theyinhibittheopeningofvoltage-gatedNa+channelsLocalanaestheticsinhibitvoltage-gatedNa+channelsandthereforethegenerationofactionpotentialsattheaxonhillock.TypeCfibresaremostsensitivetolocalanaesthetics.Reducingthethresholdpotentialwould increase action potential generation, as would inhibiting the Na+/K+ ATPase pump. LocalanaestheticsdonotstimulatetheNa+/K+ATPasepumporopeningoftheK+channels.

38.A–AldosteroneincreasesNa+−K+ATPaseactivitywithinprincipalcells,buthasnoeffectuponepithelialNa+channelsBecauseNa+isthepredominantextracellularfluid(ECF)cation,itsconcentrationwithintheECFhasthegreatest influence uponECFvolume, osmolality andNa+ excretion.Around 90–95%ofNa+ excretionoccurswithinthekidney.EpithelialNa+channelswithinprincipalcellsarethemostimportantsiteofNa+reabsorption within the kidney, although reabsorption does occur throughout the renal tubules.AldosteroneincreasesbothNa+−K+ATPaseactivityandepithelialNa+channelefficiency.

39.C–IncreasedprecapillaryconstrictionOedemaistheaccumulationofabnormallylargevolumesofinterstitialfluid.RetentionofNa+andH2Owithin the extracellular fluid results in an increasedvolumeofboth intravascular and interstitial fluid.Plasmaproteinsexertanoncoticforcethatretainsfluidwithintheintravascularspace.Iflevelsoftheseproteins fall, fluid canmore readilymove into the interstitial space and is not as readily reabsorbedwithin the postcapillary bed. Increased capillary permeability also causes increased loss of plasmaproteins, which is followed by a movement of a fluid into the interstitium. Increased postcapillaryconstrictionwillcreateanincreasedhydrostaticpressure,whichmayovercometheoncoticpressureandforcefluidoutintotheinterstitialspace.Duringmovement,skeletalmuscle-inducedcontractionofveinshelpstokeepvenouspressurelowandtherebyhelpsthereturnoffluidintoveins.Ifanindividualstandsfor long periods, this increases venous pressure, therefore making fluid accumulation within theinterstitiummorelikely.

40.D–EpithelialcellsThe anterior surface of the cornea is lined with non-keratinized stratified squamous epithelium thatreadilyregenerates.This,withtheadditionofthetearfilm,providesasmoothandregularsurfaceforthecorneatorefractlight.Ifthereisirregularityoroedemaoftheepitheliallayerthereisdisruptionoftheair–tearinterfacewhichwillconsequentlyleadtoreducedvisualacuity.

41.C–OculomotornerveThe oculomotor nerve (CN III) supplies all the extraocular muscles: superior rectus, inferior rectus,medial rectusand inferiorobliquemuscles.The twooutstandingextraocularmuscles, the lateral rectusandsuperioroblique,aresuppliedbytheabducens(CNVI)andtrochlearnerve(CNIV),respectively.Theoculomotornervealsosuppliesthelevatorpalpebraesuperiorismuscle(controlstheuppereyelid)andcausespupilconstriction.Athirdnervepalsythereforeleadstoptosis,alargepupilandaneyethatisdeviated‘downandout’(infraductedandabducted).

42. E – Tinnitus, vertigo, hyperventilation, nausea and vomiting, metabolic acidosis, respiratoryalkalosis

Becauseof itsmechanismofaction in inhibitingcyclooxygenase-1and2, aspirin ispharmacologicallyconsideredanon-steroidalanti-inflammatorydrug(NSAID),althoughitisalsoclassedasasalicylate.Inoverdose the characteristic signs and symptoms it produces aredifferent from thoseof anoverdoseofother NSAIDs. Aspirin overdose has three major groups of effects: (1) middle ear damage, causingtinnitus, vertigo and associated nausea and vomiting; (2) respiratory centre stimulation, causinghyperventilationanda resultant respiratoryalkalosis; and (3)uncouplingofoxidativephosphorylation,causinghyperthermiaandmetabolicacidosis.

43.A–Keepheronhercurrentmedicationandreviewin2weeks’timeAlthoughtheanalgesiceffectofNSAIDsusuallytakesaroundaweektodevelop,theiranti-inflammatoryeffectcantakeupto3weekstobecomeclinicallyapparent.Inthisscenario,moretimeshouldbegivenbefore considering changing thepatient’s current regimen. If there is still no effect after 3–4weeksofregular ibuprofen use, consider switching to a different NSAID, as individual responses to differentNSAIDs are variable and difficult to predict. It may take several months of trying different NSAIDsbefore themost suitableone foraparticularpatient is found.Omeprazoleasagastroprotectantagainstulcerationshouldbecontinued.Onlyaftertwofaileddisease-modifyinganti-rheumaticdrugs(DMARDs)wouldagentssuchasanti-tumournecrosisfactormonoclonalantibodiesbeconsidered.DMARDsshouldbetriedfor6monthsbeforeanabsenceofeffectisconsideredafailure.

44.C–MefenamicacidMefenamicacidcangiverisetodiarrhoeaandcanoccasionallyinduceautoimmunehaemolyticanaemia.The features of autoimmune haemolytic anaemia are low haemoglobin, macrocytosis (because ofcompensatory reticulocyte proliferation) and spherocytosis on blood film. The direct antiglobulin test(Coombstest)ispositive.

45.D–Haemophilusinfluenzae,Neisseriameningitidis,StreptococcuspneumoniaePatients who have had a splenectomy, either surgically or an autosplenectomy as a result of vaso-occlusion (for example in patients with sickle cell disease), are at an increased risk of developingoverwhelmingsepsisfromblood-borneinfectionbyencapsulatedorganisms.Thisisbecausethespleenis the key lymphoid organ involved in filtering and trapping blood-borne antigens. Asplenic patientsshould be on prophylactic daily penicillin, usually for life, and should be vaccinated against theseinfections.

46. D – A 47-year-old woman with known breast cancer presents with acute-onset right armswelling.ThearmisnothotortenderThiswomanhasacuteonsetlymphoedema,mostlikelyasaconsequenceofbreasttumourcellsinfiltratingtheaxillarylymphaticsandcausingocclusion.Accumulatedlymphresultsinswelling.Theotherclinicalscenarios,respectively,representlikelycasesofdeepveinthrombosis,anaphylaxis,septicarthritisandCollesfracture.

47.C–HypothyroidismRadioiodine is aneffective treatment forhyperthyroidism. It emitsβ-particles (high-energy,high-speedelectrons)whichhaveacytotoxicactiononthyroidfollicularcells.Theresultingdestructiondecreasesthyroid hormone secretion and thereforewill reduce hormone levels. The common complication is anunderactivethyroidglandproducingsymptomsofhypothyroidism.Thyroidhormonereplacementtherapy,e.g. levothyroxine,maybe commenced if thisoccurs.This radioiodine-thyroxine treatment sequence iscommonlyreferredtoasatypeof‘blockandreplace’regimen.

48.C–CalciumThin myofilaments contain three different proteins: actin, troponin and tropomyosin. Actin is a long-stranded protein. Two alpha helix strands of actin proteins are twisted around each other to form adouble-stranded helix. Twisting around the groove between the two actin alpha helix strands lie twoalphahelixstrandsof tropomyosin,another long-strandedprotein.Tropomyosinblocksbindingsitesofmyosinintheactingroove.Alongthishelicalstructure,atregularintervals,aretroponinmolecules.Thetroponinmoleculesareattachedtoboththeactinandtropomyosinstrands.Troponinisatrimericproteinwiththreesubunits:troponinCbindstoCa2+ions;troponinTbindstotropomyosin;andtroponinIbindstoactin.

49.C–−90mVThe membrane potential of skeletal muscle is around −90 mV. An action potential is initiated whenacetylcholineisreleasedfromthemotorneuron.Anactionpotentiallastsforabout2–4milliseconds.Thecontraction of amuscle is triggered via the initiation and propagation of an action potential along themusclefibremembrane.

50.D–OxoglutarateOxaloacetateisafour-carbonmolecule.Itreactswithatwo-carbonmoleculeofacetyl-CoAtoformthesix-carbon compound citrate. At this point in the citric acid cycle onemolecule of carbon dioxide isremovedtoformthefive-carboncompoundoxoglutarate.

Index

A

A-bands,35Abciximab,51Abdominalaneurysmaldisease,110Abducensnerve(CNVI),191ABObloodgroup,111ACEinhibitor,seeAngiotensin-convertingenzymeinhibitorAcetylcholine(ACh)receptors,16,19,194Acetyl-CoA,12,17,72Acidaemia,149Acousticneuroma,75Actin,33,194,197Actionpotential,190,198Activatedpartialthromboplastintime(APTT),17Acuteepiglottitis,129,134Acuterenalfailure,167Addisondisease,76Adductorpollicisbrevis,54Adenosinediphosphate(ADP),147Adenosinemonophosphate(AMP),14Adenosinetriphosphate(ATP),14,34,170β-Adrenergicreceptors,14Afferentneuron,69Agranulocytosis,74Albumins,96Alcohol,194Aldosterone,195Allopurinol,35,53Alpha-motoneurons,150Alternativecomplementpathway,36Alveolardevelopment,133Amacrinecells,57Aminoacids,127Aminoacyl-tRNA,91Aminoglycosides,72,74Amisulpride,132Amitriptyline,19Amlodipine,90,153AMP,seeAdenosinemonophosphate

Analcanal,190Anaphylatoxins,93Angiotensin-convertingenzyme(ACE)inhibitor,15,19,54,58,152,155Angiotensinogen,169Angiotensin-receptorblocker(ARB),15,54Aniongap,11Anteriormedianfissure,96Aorticarchsyndrome,39Aorticcoarctation,173APC(adenomatouspolyposiscoli)tumoursuppressorgene,18,35,111Apoptosis,17,19,170,177Appendicularskeleton,111APTT,seeActivatedpartialthromboplastintimeArachnoidvilli,176ARB,seeAngiotensin-receptorblockerArteries,lossofcompliancein,174Arteriole,91Aspirin(acetylsalicylicacid),90,174,196ATP,seeAdenosinetriphosphateAtrialfibrillation,148,173Atrioventricularnode(AVN),55Auerbach’splexus,14,112Autonomicganglion,131Autonomicnervoussystem,128,131Avascularnecrosis,93Axondiameter,35

B

Bacterialcellwalls,36Bacterialinfection,39Bacteroidesfragilis,15Basalganglia,11Basilarartery,37Basophils,94,96Bendroflumethiazide,73,153Benignprostatichyperplasia(BPH),16Benzodiazepine,17,127,130Beta-blockers,14,113Bicarbonate,circulatingactual,155Bilateralrenalarterystenosis,15Bilirubin,12Bipolardisorder,73Bisoprolol,113,153

Bladdermalignancy,169Bladdersmoothmuscle,129Blood,hydrogenionsin,150BloodgroupA,17BloodpH,150Blurredvision,18B-lymphocytes(B-cells),89Bone,lamellarstructureof,112Bonemarrowfailure,111BPH,seeBenignprostatichyperplasiaBradycardia,111Bradykinin,19BRCA1(BreastCancer1,earlyonset)tumoursuppressorgene,19Breastcancer,197Brunnerglands,107Buprenorphine,112Burns(multiple),73

C

Ca2+channels,37Cadherins,53Calcium,34,132cAMP,seeCyclicadenosinemonophosphateCancellousbone,108Cancer,riskofdeveloping,114Carbimazole,13,74,130Carbondioxide,71,94Carcinoidtumours,18Caseousnecrosis,14Caspase,170Catechol-O-methyltransferase(COMT),13β-Catenin,111Caudaequina,70CCK,seeCholecystokininCD4receptor,128Cellulardebris,111Cellularmigration,37Centralnervoussystem(CNS),35,131Centraltolerance,171Cephalicphase,168Cerebraloedema,194Cerebrospinalfluid(CSF),175,176Cervicalnerves,89

C5vertebra,52CFTR,seeCysticfibrosistransmembraneconductanceregulatorChemotaxis,136,147ChestX-ray,194Cholecystokinin(CCK),168Choroidplexus,176Chromatin,peripheralcondensationof15Chvosteksign,131Ciliaryganglion,133Ciliatedpseudostratifiedcolumnarepithelium,58,191Ciprofloxacin,91,93Citrate,12,72,73CK,seeCreatinekinaseClassicalcomplementpathway,89ClassIIIreactions,92Clavulanicacid,92Clexane,58Clostridiumdifficile–associateddiarrhoea,75Clostridiumperfringens,15Clozapine,52,131CNS,seeCentralnervoussystemCoccyx,70Cockcroft–Gaultformula,151Co-codamol,112Coeliacganglion,13Collagensynthesis,inhibitionof,149Colorectalcancer,18Columnarepithelium,153Complementcomponents,114COMT,seeCatechol-O-methyltransferaseConetypes(retina),56Connsyndrome,76Conusmedullaris,69Cornea,anteriorsurfaceof,196Cornealendothelialcells,193Co-trimoxazole,75Cough,134CranialnervesVII/IX,134Creatinekinase(CK),53Creatinephosphokinase,13Cricothyroidmuscles,191,193Cristae,74Cryptococcusinfections,14

CSF,seeCerebrospinalfluidC3b,opsonizationand,92Cyclicadenosinemonophosphate(cAMP),18,128,129Cyclooxygenase(COX),38,39,109Cyclooxygenase1(COX-1),135Cysticartery,172Cysticfibrosistransmembraneconductanceregulator(CFTR),18Cysticmedialdegeneration,110Cytoskeleton,154Cytosol,149

D

Daptomycin,31Deadspace,170Dehydration,167Depression,73deQuervainthyroiditis,130Dermatome,189Desmosomes,52,147Diabetes,69,110Diabeticketoacidosis,11Diapedesis,136Diaphragmaticpleura,72Diazepam,17Digoxin,52,58Dihydrofolatereductase,31,35Directreflex,132DNAbindingdomain,38DNAgyrase,32Dorsalcolumn–mediallemniscuspathway,189Doxazosin,174Duodenum,107Duramater,72

E

ECF,seeExtracellularfluidEctoderm,192,195Edinger–Westphalnucleus,11,13,132EGF,seeEpithelialgrowthfactorElastase,147Electricalcurrents,36Emptysellasyndrome,12

Endogenouschemicals,113Endothelium,89Entericnervoussystem,112Enterochromaffin-likecells,173Enterocytes,151Enteroendocrinecells,18Enzymeinducers,53Epidural,113Epithelialcadherin(E-cadherin),55Epithelialcells,190Epithelialgrowthfactor(EGF),147Epithelioidcells,149Epitope,56Erythrocytesedimentationrate,128,150Erythropoietin,95E-selectin,90Ethambutol,92Exocytosis,133Externalcarotid,33Extracellularfluid(ECF),195Extracellularosmolality,191Eye,ciliarymuscleof,13

F

FactorVIIIdeficiency,111Fasciculusgracilis,71Fastfibres,33Fattransport,51Femoralartery,32,51Fentanyl,54,110Fibrinclot,148Fibroblastgrowthfactor(FGF),147Finasteride,165q(chromosome),35Flight-or-fightresponse,16,128Flumazenil,17Fluoroquinolones,91,93Folicacid,91,93

G

GALT,seeGut-associatedlymphoidtissueGamma-aminobutyricacid(GABA),37,108,130

Gamma-motoneurons,149Gammatubulin,74Gasexchange,171Gastric(hydrochloric)acid,169Gastricarteries(rightandleft),18Gastricchiefcells,167Gastricinhibitorypolypeptide(GIP),168Gastricveins(leftandright),12Gastrocnemius,89Gastrointestinalsystem,parasympatheticinnervationof,134Genetics(autosomaldominant),15Giantcellarthritis,69Glomerularfiltrationrate(GFR),170Glossopharyngeal(IX)nerve,51Glossopharyngealparasympatheticneurons,132,134Gluconeogenesis,127Glucuronyltransferase,12Gluteusmaximus,55Glycopeptideantibiotics,70GlycoproteinIIb/IIIareceptors,89Gobletcells,154‘Golfer’selbow,’95Golgiapparatus,34G-proteinreceptors,132Gravesdisease,130GTPaseproteins,76Guanosinetriphosphate(GTP),70,109Gut-associatedlymphoidtissue(GALT),70,71

H

Haematopoiesis,110Haemoglobin,15,91,94HaemophiliaA,111Haemophilusinfluenzae,128,134,197Haversiancanals,113HbS,seeSicklecellhaemoglobinHearingloss,asymmetrical,75Hemidesmosomes,52,147Henderson–Hasselbalchequation,151,171Heparin,17Hepaticvein,91Hereditaryretinoblastoma,69Hereditaryspherocytosis,129

Heschl’sconvolution,12Hilton’swhiteline,anusbelow,190Histamine,173HMG-CoA(3-hydroxy-3-methylglutaryl-coenzymeA)reductase,34,39Horner’ssyndrome,54Hotpotatovoice,135Hydrogenionsecretion,170Hydroxyapatite,112Hyoscine,175Hyperaldosteronism,76Hypercalcaemia,52Hypercholesterolaemia,34Hyperkalaemia,76Hyperthyroidism,13,130,197Hypertrophichearts,173Hyperventilation,150Hypocalcaemia,131Hypogastricnerve,129Hyponatraemia,72,73Hypothalamicthermostat,38,113

I

Ibuprofen,130IgA56IGF-1,seeInsulin-likegrowthfactor-1IgGantibodies,57,89,133IL-2,seeInterleukin2IL-8,133Ileocolicartery,177Ileum,56,114Iliopsoas,96Imidazobenzodiazepine,17Incomitantstrabismus,75Inferiorglutealnerve,55Inferiorturbinates,192Inferiorvenacava(IVC),92–93Infliximab,35Innateimmuneresponse,170Insulin-likegrowthfactor-1(IGF-1),147Integrins,133Interferon,150Interleukin2(IL-2),38Intermediatefilaments,152

Internalcarotidartery,32Interosseousmembrane,153Interstitialfluid,167Intraepitheliallymphocytes,70Intrinsicfactor,173Intrinsicrenalfailure,167Irondeficiency,109Isocitratedehydrogenase,71Isosorbidemononitrate,52IVC,seeInferiorvenacava

J

Jejunum,109,154Juxtaglomerularapparatus,189

K

Kappasegment,55Keloidformation,154Keratinizedepithelium,155Ketones,11Koilonychia,109Krebscycle,17,107

L

Labetalol,151β-Lactams,90Lactate,148Lacteals,51Laminins,37Lateralepicondyle,95L-cells,58LDLs,seeLow-densitylipoproteinsLeberhereditaryopticneuropathy(LHON),76Leftatrialsize,176Leftgastricvein,90Legionellapneumophila,18Leukocytes,96,132,133,136LeukotrieneB4,133,135Lincosamides,75Lipopeptideantibiotics,31Lisinopril,155Lithium,73

Liverfailure,113Loopdiuretics,168Low-densitylipoproteins(LDLs),34Ludwigangina,128Lungsegments,115Lymphoedema,197Lysosomes,147

M

MAC,seeMembraneattackcomplexMalaria,17Maleurethra,94Malignanthyperpyrexia,17MALT,seeMucosa-associatedlymphoidtissueMannose-bindinglectin,91MarginalarteryofDrummond,57Mastcells,94Matrixmetalloproteinases(MMPs),154Maxillarysinus,193Meckeldiverticulum,56Mediallongitudinalfasciculus,73Mefenamicacid,197Meissner’splexus,71,127MELDscore,151Membraneattackcomplex(MAC),93Ménièredisease,76Mesoderm,tissuesderivedfrom,153MessengerRNA(mRNA),147,154Metabolicalkalosis,12Methicillin-resistantStaphylococcusaureus(MRSA),15Methyldopa,174Metoprolol,113Microtubules,69,132,152Midazolam,127Misoprostol,152Mitochondria,34,37,73Mitosis,sequenceof,37MMPs,seeMatrixmetalloproteinasesMonoclonalantibodies,51,151Monocyte,52Morphine,112MPO,seeMyeloperoxidasemRNA,seeMessengerRNA

MRSA,seeMethicillin-resistantStaphylococcusaureusMucosa-associatedlymphoidtissue(MALT),70Mureceptor,108Muscarinicreceptors,128Musclebreakdown,127Muscularisexterna,14,112Muscularismucosa,127Myastheniagravis,19,194Mycobacteria,92Mycobacteriumtuberculosis,14Mycoplasmatuberculosis,110Mycoticaneurysms,39Myelinatedneurons,35,192MyelinatedtypeBfibre,130Myeloperoxidase(MPO),39

N

Na+channel,192,195NADH,17,71Na+/K+/2Cl−co-transporter,168Nasalpassages,189Nasopharynx,192Necrosis,15,177Necrotizingfasciitis,14,15Neisseriameningitidis,197Nephrotoxicdrugs,167Nervoussystem,partsof,131Neuraltubedefects,91Neurologicaldamage,93Neuromuscularjunction(NMJ),16,19,193Neutrophils,114Nicorandil,57Nicotinicreceptors,34,135Nipple,189Nitricoxide,1295-Nitroimidazoles,32Non-steroidalanti-inflammatorydrugs(NSAIDs),54,109,113,135,151,196Nordazepam,130

O

Oculomotornerve(CNIII),11,196Oedema,195

Oesophagus,71,192Olanzapine,36,132Omeprazole,73,152Opiatewithdrawal,112Opioidreceptors,108Opsonization,92Opticpapilla,56Osteoblasts,31Osteoclasts,32Osteoidosteomas,112Osteoidproduction,31Osteomalacia,170Osteonecrosis,93Ovariancancer,19Ovaries,37,38Oxaloacetate,12,17,72,77,107,198Oxazolidinones,74Oxoglutaratedehydrogenase,70

P

Panethcells,53,155Paracetamol,54,110Paralyticsquint,75Parasympatheticinnervation(vagusnerve),15Parasympatheticsystem,129Parathyroidhormone(PTH),127Parietalcells,169Parkinsondisease,13Partialpressureofcarbondioxide,150Partialpressureofoxygen(arterial),150Patella,58,108Patentductusarteriosus(PDA),169Patient-controlledanalgesia(PCA),112PDGF,seePlatelet-derivedgrowthfactorPectoralmuscles,11Pelvicfloor,musclesof,95Penicillins,74Pepsinogen,167PeptideYY,58Peptidoglycans,36,70Peptidyl-tRNA,72Perforatingcanals,113Peripheralnervoussystem(PNS),35

Peyer’spatches,114p53(protein53)tumoursuppressorgene,36,114PGE2,seeProstaglandinE2Phagocytosis,133Pharyngealtonsils(adenoids),189Piamater,70Pituitarygland,12Plasmaproteins,96,191Plasminogen,96Plateletaggregation,89,174Plateletcountrange(normal),109Platelet-derivedgrowthfactor(PDGF),147PNS,seePeripheralnervoussystemPolyarteritisnodosum,38Polycystickidneydisease(PKD),15Polycythaemiarubravera,75Poplitealartery,175Portalvein,172Posteriorcerebralartery,37Postganglionicneurons,11,132Potassiumchannels,73Potassiumiodide,130Preganglionicneurons,131,132,133Pregnancy,152,175–176Primaryauditorycortex,12P–Rinterval,172Proprioception,189Propylthiouracil,13Prostacyclinproduction,inhibitionof,131ProstaglandinE2(PGE2),135Pterygopalatineganglion,134PTH,seeParathyroidhormonePulmonaryartery,90Pulselessdisease,39Pupillaryconstriction,54Pupillaryreflex,disruptionof,69Pyramidaldecussation,96,190Pyridostigmine,16Pyrogens,113Pyruvate,12,72,107

Q

QRScomplex,55,172

Quetiapine,132Quinine,16Quinolones,32Qwave,176

R

RAAaxis,seeRenin–angiotensin–aldosteroneaxisRadioiodine,74Ramipril,54,153Rasgene,mutationsin,76RB1(retinoblastoma)gene,69RCA,seeRightcoronaryarteryReactiveoxygenspecies,147Rectusfemoris,33Refeedingsyndrome,190,194–195Remakbundles,112Renalarteries,92Renaldisease,severe,170Renalfailure,acute,167Renin–angiotensin–aldosterone(RAA)axis,169Reninsecretion,189Resolution,38Respiration,principlemusclesof11Respiratoryalkalosis,150Respiratorybronchioles,96Restingpotential(neuronmembrane),36Retina,layersof,57Reyesyndrome,90Rheumatoidarthritis,151Rhinovirus,75Ribnotching,174Ribosomes,dissociationof,19Rifampicin,32Rightcoronaryartery(RCA),168Risperidone,131Rofecoxib,109Rotatorcuffmuscles,56Roughendoplasmicreticulum,34,154Rwave,173

S

Sacralarea,95

SAN,seeSinoatrialnodeSarcomere,32Sartoriusmuscle,33Scarformation,154Schwannoma(vestibularnerve),75Selectiveserotoninreuptakeinhibitors(SSRIs),52,56Self-reactivecells,171Sensoryreceptor,69Sepsis,197Septicshock,114Serratusanterior,1417p(chromosome),36Sharpeyfibres,112Shoulder,medialrotationof,51Sicklecellhaemoglobin(HbS),107Simvastatin,53Sinoatrialnode(SAN),57,168Skeletalmuscle,membranepotentialof,198Slowfibres,33Smallintestine,mucosaof,115Smoothmuscle,58,74,129,147Sodiumchannels,31S(synthesis)phase(cellcycle),33Sphincterrelaxation,134Spinalreflex,193Spleenlymphatics,55Splenectomy,197Splenicartery,110Spongybone,108Squamouscellcarcinoma,52Squamousepithelium,152SSRIs,seeSelectiveserotoninreuptakeinhibitorsStaphylococcusaureus,110,133Statins,34,39,53Steroidreceptor,38Stomach,71,147,155Stratifiedsquamousepithelium,71Streptococcus,128Streptococcuspneumoniae,197Streptococcuspyogenes,14Subarachnoidspace,189Submandibularglands,ductsof,190Submucosa,71

Succinyl-CoA,70,108Sulphamethoxazole,75Sulphonamides,32,92Superiorglutealartery,175Superiorvenacava(SVC),115Suxamethonium,16,17

T

‘Tailor’smuscle,’33Takayasuarteritis,39Tardivedyskinesia,52TCAcycle,seeTricyclicacidcycleT-cellreceptor,55Temporallobe,12Tendon,58,193‘Tenniselbow,’95Terminalileum,58Testicularartery,53Tetracyclines,91,130Tetrahydrofolicacid,31T4(thyroxine),half-lifeof,149Thalassaemia,92Thiazidediuretics,73Thioureylenes,13,149Thrombocyte,14ThromboxaneA2,131,135,147Thyroid,31,94,130Thyroid-stimulatinghormone(TSH),130Tidalvolume,172Tirofiban,174Tissueplasminogenactivator(t-PA),96T-lymphocytes(T-cells),56,89,114,171TNF-α,seeTumournecrosisfactor-αToll-likereceptors(TLRs),128Tongue,anteriortwo-thirdsof,54Totallungcapacity,172Trabecularbone,108Trachea,C-shapedcartilaginousringsof,56Trachealis,58TractofGoll,71TransferRNA(tRNA),147,154Transitionalcellcarcinoma,169Tricepsbrachii,13

Tricuspidvalve,53–54Tricyclicacid(TCA)cycle,12,72,107Tricyclicantidepressant,19Trigeminalnerve(CNV),177Trimethoprim,31,35,75Trochlearnerve,191Tropomyosin,194,197Troponin,194,197TSH,seeThyroid-stimulatinghormoneTuberculosis,14,35Tumournecrosisfactor-α(TNF-α),35,38,151Turbinates,192Turnersyndrome,173TypeIalveolarcells,134TypeIcollagen,113TypeIIcollagen,51TypeIIIcollagen,150

U

Upperrespiratorytractinfections(URTIs),75Urineformation,168Uterus,38

V

Vagalparasympatheticneurons,15,133Vagusnerve(cranialnerveX),16,72,193Vascularendothelialgrowthfactor(VEGF),147Vascularresistance,91Vasodilation,148Vasopressin,94,194Ventricularrepolarization,172Ventricularseptaldefects(VSDs),176Viralupperrespiratorytractinfections,75Vision,blurred,18Vitalcapacity(lung),172VitaminB12,90,93Volkmanncanals,113Voltage-gatedNa+channels,195

W

Warfarin,148Water(body),95,167

Woundcontraction,148,149

X

Xanthopsia,18X-linkeddisorder,111

Y

Yellowvision,18

Z

Z-lines,35Zonulaadherens,53Zonulaoccludens,51Zymogen,167