PHYSIOLOGY MCQs August 2011

Unclassified Physiology

Resp quotient in sepsis decreased due to

1. Increase CO2?

2. Fat metabolism

3. Hypoxaemia

4. Elevated Lactate

5. Fever

Following moderate Exercise

1 Arterial lactate increase

2. Decreased pO2

3. Raised pCO2

4. Increased O2 extraction/ (or was it decreased SvO2?)//decreased o2 extraction i think it said

5. decreased arterial pH

Sympathetic supply of the GIT:

1. T1 - S4

2. T5 - L3

3. other combinations

General physiology

Resting membrane potential in skeletal muscle:

A. Approximately the same as the diffusion potential for potassium

B. Direct effect of Na/K ATPase

C. Mainly due to gibbs donnan effect

Henrys law states...

A. Number of molecules dissolved in solution proportional to partial pressure of that gas in equilibrium.

B. Boyles law

C. ...Other wrong answers

RMP due to

A. Gibbs-Donnan effect

B. Na/K ATPase

Gibbs-Donnan Effect:

A. explains distribution of charge between intra and extraVASCULAR space

B. explains difference in ionic concentration gradients

C. explains distribution af charge between inta and extracellular spaces

D. ?

E.

Na-K+ ATPase pump

A. Digoxin binds to K+ binding site

B. Stimulated by smaller cell size

C. 2 Na+ out, 3 K+ in

Fluid & electrolytes

FE11 Question about daily water losses similar to the linked MCQ. Pretty sure all answers were incorrect leaving option "E. none of the above" as the most likely. Can't remember the responses.... anyone?

Hartmanns is

A. Isotonic

B. Contains Ca 2 mmol/L

C. Contains lactate 5 mmol/L

D. ?

Magnesium is needed for

A ? Na/K ATPase function

B ?

C?

D?

E?

ECG changes in hyperkalaemia

A QT prolongation

B ST depression

C No P wave

D

E

Hyperkaleamia and ECG changes

A P wave absence

B QT prolongation

ST flattening

Acid-base physiology

AD24 Buffering by Hb better than by plasma proteins because

A. Hb has 38 carboxyl residues

B. great amount

C. plasma poreint pKa near pH of Blood

D.

E.

AD25 If pH is 7, then H+ concentration of pure water is:

A. O

B. 40 nmol/L

C. 70 nmol/L

D. 100nmol/L

E. 1000nmol/L

AD26 Fluid loss from pancreatic fistula with normovolaemia

A. Hypercholremic metabolic acidosis

B. ?

all other combos

AD27 With pCO2 200mmHG, what else would you find

A. Hyperkalemia

B. Bradycardia

C. Hypercalcaemia

Respiratory Physiology

In the upright lung (or something like that):

A. The apical alveolar PCO2 is low (28mmHg)

B. The basal alveolar V/Q is high (approx 3)

C. The apical alveolar V/Q is low (approx 0.6)

D. ?

Highest total O2 consumption

1. Brain

2. Heart

3. Kidney

4. Liver

Which organ has the highest total oxygen consumption at rest:

A. Heart

B. Brain

C. Liver

D. Skin

E. Kidney

Plus another question straight out of the O2 consumption table regarding the O2/100g/min column

During resp cycle

1. Intrapleural pressure between -8 and -5mmHG

2. Tracheal flow sinusoidal

3. Alvelar pressure between -2 to +2cmH20

4. IPP is sinusoidal

5. Flow is 5L/s

CVS physiology

New - Myocardial cells

A Gap junctions at Intercalated Discs

With regards to the coronary circulation flow: (new)

A. Flow is initially maintained in VF if perfusion pressure is maintained

B. There is usually no difference between endocardial and epicardial flow

C. Flow in the left ventricle is lowest at mid-systole

D. Sympathetic stimulation directly decreases flow (or something like that) I thought it was 'increases'

E. ?

Answer ?A

With regards to coarctation of the thoracic aorta: (new)

A. Cardiac output is 1.5x normal

B. Flow in all parts of the body is normal

C. The baroreceptors cease to function

D. Vascular resistance in the lower body circulation is greater than that in the upper body

E. BP in arm and leg equal

Not new. See CV39

Chronic anaemia causes:

A. Increased stroke volume

B. Increased Mean Arterial Pressure

C. Increased TPR

D. Increased mixed venous PO2

A. Multiple Googled papers say

Repeat: baroreceptors are found everywhere except:

A. Carotid body

B. Carotid sinus

C. Vena cava

D. Aortic arch

E. Right atrium

Normal effects of aging

A. Wide pulse pressure

B. Increased aortic elasticity

C. Increased ventricular compliance

D. Increased diastolic pressure

A

During increased intrathoracic pressure of a Valsalva manoeuvre

A. Diastolic filling of the rights ventricle is decreased

B. Arterial baroreceptor activation produces bradycardia

C. Increased venous pressure augments cardiac output

D. Total peripheral resistance is decreased

E. Arterial blood pressure initially decreases

Which ONE of the following does NOT affect brain blood flow

A. pCO2

B. pH in brain intersitum

C. p02

D. Cerebral activity

E. CSF production

E

Which of the following happens in diastole

A. C wave

B. Aortic valve closure

C. T wave in ECG

D. Peak aortic blood flow

E. Second heart sound

Which of the following increase PVR

1. Hypocarbia

2. Alkalosis

3. Raised pulmonary arter p

4. Raised LAP

5. None of the above

None of the above. ...? Hypercapnoea causes vasoconstriction (unique to lung); i.e. hypocapnoea reduces PVR. Acidosis both potentiates HPV; i.e. alkalosis reduces PVR. Raised PA and LA pressures both cause recruitment and reduce PVR. But high school exams taught us that none of the above is never the correct answer!! Comments?

Renal physiology

Regarding the kidney:

1. Oxygen consumption higher in medulla than cortex

2. O2 consumption correlates with active transport of sodium

3. ...Can't remember

Which has the greatest renal clearance?

A. PAH

B. Glucose

C. Urea

D. Water

E. Insulin

GI physiology

Small intestine (or something)

A. More bacteria than large bowel

B. Gastric acid and fast transit time reduce number of bacteria

C. Defence against bacteria is by IgA and cellular immunity

D. Same amount bacteria present in small and large bowel but different types

E. Is sterile

Sympathetic innervation of the gut comes from:

A. L1-L3

B. T6-S3

C. T2-T12

D. T6-T10

A mixture of options was given, definitely one involving sacral roots, and one only involving lumbar.

Blood & immunology

With regard to the ABO blood system

A. It refers to red cell antibodies

B. Group O are universal donors as they have no antibodies

C. Groups AB are universal recipients as they have no antibodies in their blood

D. Group A blood has no carbohydrate moiety extending the H antigen

E. ?

Endothelium produces all except

A. TXA2

B. endothelin

C. prostacyclin

D. Nitric oxide

Not produced in liver

A. Immunoglobilun

B. ?

Granulocytes :

A. Circulating life 3-5 days

B. Produced in lymph nodes and marrow

C. One nucleus

D. Move via amoeboid movement through tissue

E. Activated by immunoglobulins

Endocrine & metabolic physiology

Actions of Insulin

A. Stimulate HSL

B. Stimulate LPL

C. ?

Erythropoietin

A. Secretion stimulated by increase sympathetic activity

B. Stimulates production of megakaryocytes

C. Excreted unchanged in urine

D. Only produced in the liver

E. Production facilitated by metabolic and respiratory acidosis

Actions of PTH on kidney

A. Increase Ca reabsorption, decrease PO4 reabsorption

B. Increase Ca and PO43- reabsorption

C. Decrease Both

D. Increase PO43-, decrease Ca

This was divided up by region, 1 answer was collecting duct, the other 3 maybe 4 were for proximally ascending, LoH and DCT.

Neurophysiology

The NMDA receptor:

A. Glycine required as a modulator for opening of ionic channel

B. Activated by Mg2+

C. Mainly pre synaptic

Contents of CSF cf plasma:

A. K+ 60%

B. Glucose 30%

C. HCO3- 80%

D. Na+ 80%

E. Cl- 80%

Physiology of muscle & NMJ

With regards the nicotinic NMJ:

A. MEPP increased with hypocalcaemia

B. Random release of acetylcholine occurs

C. MEPP of 5 mV occurs

D. ?

Immediate source of energy for muscle contraction

A. ATP in all muscles

B. Creatine phosphate in smooth, ATP in cardiac

C. etc, etc other wrong combos

Something about smooth muscle contraction

A. Does not require an action potential to contract

B. Has a spike action potential, and not a plateau like ventricular muscle

C. ?

Maternal, foetal & neonatal physiology

Closure of the ductus arteriosus occurs due to:

A. Oxygen mediated smooth muscle constriction

B. Pressure in LA>RA

C. Pressure in aorta > Pulmonary artery

D. Increased systemic SVR

E. Increased prostaglandins

Changes in pregnancy include all except:

A. Increase in O2 consumption by 20%

B. Increase in TLC by 15%

C. Increase in VC by 15%

D. Decrease in FRC by 30%

E. Increase in TV by 20%

Brown fat:

A. Produces ATP and Heat

B. Insulates the thermoreceptors around great vessels of the neck

C. Is autonomically mediated

D. Extramitochondrial uncoupling of oxidative phosphorylation

Clinical measurement

Which of the following does not use change in electrical resistance:

A. Thermocouple

B. Bourdon gauge

C. Katharometer

D. Thermistor

E. Strain gauge transducer

All of the following pressures are equivalent EXCEPT:

A. 1 Atm

B. 760mmHG

C. 100kpa

D. 102cmH20

E. 100,000 newtons per m2

Absolute humidity

A. Measured in g/m3

B. is saturated vapour pressure

C. Measured by hair hygrometer

D. Measured by wet and dry bulb hygrometer

E. Equals water vapour present/vapour present at saturation

SaO2 underestimated in

1. Caboxyhb

2. High bilirubin

3. HBF

4. Sickle cell

5 fluroscein dye

Speed of Ultrasound waves affected by

A. Frequency

B. Type of Tissue

C. Temperature

D. Wavelength

E. Type of probe