NBDE IPhysiology Review

I.– Structure and function of connective tissue (8)– Structure and function of membranes (4)– Nervous System (9)– Muscle System (6)– Circulatory System (9)

_____________________________________II.– Respiratory System (6)– Renal System (6)– Digestive System / Nutrition (10)– Endocrine System (8)– Genetics (5)

PHYSIOLOGY I

Embryology• Mesoderm

– Mesenchyme/Connective tissue: skeleton, muscle, neurovascular, spleen

• In-between (endoderm and ectoderm)

• Endoderm– Digestive tract, Liver, Pancreas (GI organs)

• Inside

• Ectoderm – Skin, Neural crest derivatives (brain/head and neck nerves)

• Outside

Archenteron:

primitive gut

Embryology1. Morula 2. Blastula

3. Gastrula

Establishment of 3 germ layers

CONNECTIVE TISSUE

• Soft tissue• Hard tissue

The craniofacial bones differ from long bones embryologically because most craniofacial bones develop through

A. Endochondral ossificationB. Membranous ossificationC. Primary mineralizationD. Secondary mineralization

Which of the following proteins is LEAST likely to be found in fully developed fibrous connective tissue?

A. FibronectinB. ElastinC. OsteonectinD. CollagenE. Vimentin

Which of the following proteins is LEAST likely to be found in fully developed mineralized hard tissue?

A. OsteopontinB. TuftelinC. OsteonectinD. EndothelinE. Bone morphogenic protein (BMP)

Which of the following represent(s) a matrix protein of enamel?

A. Carboxyglutamic acid-containing proteinsB. Type I collagenC. AmelogeninD. ProteoglycanE. Elastin

Which of the following proteins is LEAST likely to be found in enamel formation?

A. AmelogeninB. AmeloblastinC. EnamelinD. Elastin E. Tuftelin

Which of the following noncollagenousprotein components BEST characterizes dentin matrix?

A. LamininB. VimentinC. PhosphophorynD. OsteonectinE. Fibronectin

Which of the following is the major protein component of cementum?

A. ElastinB. KeratinC. CollagenD. AmelogeninE. Fibrin

Which of the following proteins is LEAST likely to be found in mucosal epithelium?

A. FilaggrinB. CytokeratinC. InvolucrinD. VimentinE. Transglutaminase

Predominant tissue matrix proteins,hardest to softest…

• Enamel– Amelogenin, Ameloblastin, Enamelin, Tuftelin

• Bone– Osteonectin, Osteopontin, Osteogenin, BMP, Collagen

• Cementum– Collagen

• Dentin – Collagen (type I), DMP, Phosphophoryn

• Fibrous connective tissue– Collagen, Fibronectin, Elastin, Vimentin, Laminin

• Epithelium– Keratin, Involucrin, Filaggrin, Transglutaminase, Melanin

• Vessels– Endothelin, VWF, VEGF

MEMBRANES

The fluid mosaic model for membrane structure proposes that

A. The outer and inner faces of the membrane are identical

B. Peripheral proteins are situated only on the outer face of the plasma membrane

C. Integral proteins are associated with the hydrophobic phase of the bilayer

D. Both polar and non-polar ends of membrane phospholipids are within the hydrophobic phase of the bilayer

The cell membrane

CholesterolIntegral protein

Phospholipid bilayer

The most abundant non-phospholipidcomponent of the cell membrane is

A. CholesterolB. DeoxycholateC. ProstaglandinD. MacroglobulinE. Triacylglyceride

Each of the following lipid classes is incorporated into membranes EXCEPT one. Which one is the EXCEPTION?

A. CholesterolB. GangliosideC. TriglycerideD. SphingomyelinE. Phosphatidylcholine

Which of the following is LEAST descriptive of lipids?

A. NonpolarB. Carbon-containingC. HydrophobicD. Hydrophilic

The largest amount of body water can be found in which of the following?

A. UrineB. Blood plasmaC. Intracellular fluidD. Interstitial fluidE. Stomach and intestines

Intracellular and interstitial body fluids have similar

A. Total osmotic pressureB. Colloid osmotic pressuresC. Sodium ion concentrationsD. Chloride ion concentrationsE. Potassium ion concentrations

NERVOUS SYSTEM

The spinal cord is the only structure in the central nervous system necessary for which of the following body functions?

A. RespirationB. Simple reflexC. Temperature regulationD. Coordinated muscle movement

Decreased response of sense organs when exposed to a constant stimulus is called

A. OcclusionB. SummationC. AdaptationD. FacilitationE. Sensory deprivation

An action potential in a nerve fiber is considered to be related to

A. The changed orientation of molecules in the membrane giving rise to a static potential difference

B. The entry of sodium ions followed by the exit of potassium ions

C. A breakdown of metabolic products resulting in different concentrations of potassium across the membrane

D. The flow of electrons across the membrane following change in membrane permeability

Absolute Relative

Na+ into cell K+ out of cell

“All or nothing”

If an axonal membrane transiently becomes very permeable to Na+ ions, then the membrane potential of the cell wall will approach

A. -70 mVB. -60 mVC. -50 mVD. 0 mVE. +60 mV

When are nerve fibers hypoexcitable?

A. During resting potentialB. At the firing levelC. During local depolarizationD. During negative after-potentialE. During positive after-potential

The maximal frequency of impulses that can be carried by a nerve fiber is limited by which of the following?

A. Intensity of the stimulusB. Diameter of the nerve fiberC. Duration of the absolute refractory periodD. Duration of the relative refractory period

GABA increases the permeability of postsynaptic membranes to which of the following ions?

A. SodiumB. CalciumC. ChlorideD. MagnesiumE. Potassium

Glutamate decarboxylase, an enzyme that catalyzes the formation of gamma-amino butyric acid (GABA), is unique to

A. BoneB. SkinC. Heart muscleD. Nervous tissueE. Connective tissue

Key neurotransmitters:Catecholamine biosynthetic pathway

Tyrosine ! L-Dopa (dopamine) !Norepinephrine ! Epinephrine

Degraded by enzymes:– MAO– COMT

MUSCLE SYSTEM

• Cardiac• Skeletal • Smooth

Which of the following represents a striated muscle that contains transverse tubules, a slow rate of calcium sequestration, and is inhibited by acetylcholine?

A. CardiacB. SkeletalC. Multi-unit smoothD. Single-unit smooth

Calcium ions initiate contraction in skeletal muscle when they

A. Bind to T tubulesB. Bind to troponinC. Interact with actinD. Interact with myosinE. Bind to sarcoplasmic reticulum

During exercise, muscle tissue accumulates lactic acid. As a result, erythrocytes passing through capillaries in the muscle

A. Release more CO2

B. Absorb more CO2

C. Release more O2

D. Both 1 and 3 aboveE. Both 2 and 3 above

CO2 + H2O "! H2CO3+ "! HCO3

- + H+

Le Chatelier’s (note it has nothing to do with Oxygen)

The absolute refractory period of skeletal muscle is an interval during which

A. The stimulus is more than normally effectiveB. The threshold is loweredC. The muscle is relaxedD. No stimulus is effective

CIRCULATORY SYSTEM

• Cardiovascular

Which of the following portions of the cardiovascular system contains the greatest volume of blood?

A. ArteriolesB. CapillariesC. Systemic veinsD. Chambers of the heartE. Pulmonary vasculature

Edema may be caused by

A. Constriction of arteriolesB. Increased permeability of capillariesC. Reduced blood pressure in the capillariesD. A tissue oncotic pressure that is lower than

that of plasma

Artery

Lymph

Interstitial space/fluid

Interstitial space/fluid

Which of the following changes promotes the formation of extracellular edema?

A. Increase in tissue fluid hydrostatic pressureB. Increase in plasma protein concentrationC. Decrease in capillary hydrostatic pressureD. Capillary filtration exceeds capillary absorptionE. Capillary absorption exceeds capillary filtration

Which of the following could be beneficial in reducing edema in the arms of women who have had radical mastectomy with removal of axial lymph nodes?

A. Hypertensive agentsB. Avoidance of all diuretic agentsC. Increase interstitial oncotic pressureD. Decrease interstitial hydrostatic pressureE. Administration of a plasma volume expander

Which of the following is MOST often associated with free fatty acid transport in human blood?

A. AlbuminB. GlobulinC. CholesterolD. SphingolipidE. Mucopolysaccharide

The main function of plasma globulins is to

A. Maintain colloid osmotic pressureB. Provide the body with both natural and

acquired immunityC. Act as a framework on which clot formation

may occurD. None of the above

Distended veins in the neck result from which of the following?A. Pulmonary edemaB. Hemolytic anemiaC. Systemic hypotensionD. Congestive heart failure

Cardiac output is expressed as a product of

A. Stroke volume and heart rateB. Venous pressure and heart rateC. Stroke volume and respiratory rateD. Stroke volume and diastolic fillingE. Venous pressure and coronary blood flow

CO=HR x SV (Starling’s Law: CO=CR)

In the absence of compensatory changes, a drop in blood pressure results from

A. VasoconstrictionB. Increased hematocritC. Increased stroke volumeD. Increased cardiac outputE. Decreased venous return

A marked fall in the oxygen tension in arterial blood would stimulate the receptors in the

A. Aortic arch and carotid sinusB. Walls of the great veinsC. Aortic and carotid bodiesD. Respiratory center

Sounds heard during systole in the antecubital space are produced by

A. Closure of AV valvesB. Closure of the aortic valveC. Turbulent blood flow through the arteryD. Laminar blood flow through the occluded artery

The first heart sound is produced by

A. Ejection of blood from the ventriclesB. Filling of the ventriclesC. Closure of the AV valvesD. Closure of the semilunar valvesE. Turbulent blood flow through the artery

Heart Sounds

• Systole – ejection of blood from ventricles

• Diastole – filling of ventricles

• S1 – 1st heart sound– Closing of the

atrioventricular valves: mitral and tricuspid

• S2 – 2nd heart sound– Closing of the

seminular valves: aortic and pulmonary

In which of the following conditions might the systolic blood pressure be abnormally high?

A. Cardiac shockB. Heart failureC. Anaphylactic shockD. Decreased arterial blood complianceE. Ventricular fibrillation

Decreased arterial blood pressure upon standing is compensated by

A. Decreased heart rateB. Dilation of mesenteric vesselsC. Constriction of systemic arteriolesD. Dilation of venules

Administration of a local anesthetic with epinephrine will MOST likely produce which of the following cardiovascular effects?

A. Increased heart rateB. Decreased heart rateC. Increased diastolic blood pressureD. Decreased systolic blood pressure

NBDE IPhysiology Review

I.– Structure and function of connective tissue (8)– Structure and function of membranes (4)– Nervous System (9)– Muscle System (6)– Circulatory System (9)

_____________________________________II.– Respiratory System (6)– Renal System (6)– Digestive System / Nutrition (10)– Endocrine System (8)– Genetics

PHYSIOLOGY II

RESPIRATORY SYSTEM

In respiratory acidosis, arterial CO2 content and pH become abnormal. Which of the following BEST describes their respective changes?

CO2 pH

A. Increases IncreasesB. Increases Decreases

C. Decreases Increases

D. Decreases Decreases

CO2 + H2O "! H2CO3+ "! HCO3

- + H+

Le Chatelier’s (note it has nothing to do with Oxygen)

Most of the CO2 in blood is combined as

A. Acetic acidB. BicarbonateC. Carbonic acidD. Carbaminohemoglobin

Hyperventilation alters acid-base balance of arterial blood by

A. Increasing CO2 and increasing pHB. Increasing CO2 and decreasing pHC. Decreasing CO2 and decreasing pHD. Decreasing CO2 and increasing pH

CO2 + H2O "! H2CO3+ "! HCO3

- + H+

Le Chatelier’s

Which of the following stimulates vagalnerve endings in the lung parenchyma and inhibits respiration?

A. Decreased arterial pH B. Expansion of the lungsC. Decreased alveolar oxygen tensionD. Increased alveolar carbon dioxide tension

RENAL SYSTEM

MOST fluid reabsorption by the kidneys occurs in which of the following?

A. Distal tubuleB. Proximal tubuleC. Collecting ductD. Ascending loop of HenleE. Descending loop of Henle

Each of the following appears in the glomerular filtrate in concentrations approximately equal to those in plasma EXCEPT one. Which one is the exception?

A. UreaB. GlucoseC. Amino acidsD. Steroid hormonesE. Plasma electrolytes

ADH receptors in the nephron are located on the tubular membrane of which of the following?

A. Distal tubule B. Proximal tubuleC. Ascending loop of HenleD. Descending loop of Henle

Which of the following represents the major force that causes glomerular filtration?

A. Tubular hydrostatic pressureB. Tubular colloid osmotic pressureC. Glomerular capillary hydrostatic pressureD. Glomerular capillary colloid osmotic pressure

Which of the following structures of the kidney most actively regulates blood pressure?

A. Proximal tubuleB. Distal tubule C. Loop of HenleD. Juxtaglomerular apparatus

The clearance rate for a substance that is completely removed from the blood in the urine during one pass through the kidney is equal to which of the following?

A. Renal plasma clearanceB. Filtration fractionC. Glomerular filtration rate D. Tubular transport maximum

Filtration

Tubule

Secreted into tubule

Reabsorbed into blood

*Inulin is filtered, but not reabsorbed or secreted, so the RPC=GFR

If the renal plasma clearance of a substance which is freely filtered is less than that of inulin, then

A. The substance becomes bound to protein in the tubules

B. There is a net secretion of the substance in the tubules

C. There is a net reabsorption of the substance in the tubules

D. The substance is neither secreted nor reabsorbed in the tubules

DIGESTIVE SYSTEM / NUTRITION

Which of the following is NOT a primary electrolyte of saliva?

A. SodiumB. CalciumC. FluorideD. PotassiumE. Bicarbonate

Tooth erosion in bulimic patients is due to

A. HyposalivationB. HypersalivationC. Action of pepsinD. Excessive fluoride intakeE. Solubility of hydroxyapatite in acid

Bulimia

Hyposalivation

Digestive SystemPhysiology / Biochemistry

– What happens to a bolus of food during digestion? What do the components become?

– Use your knowledge of anatomy.

Gross metabolism:• Proteins (-amino acids)• Carbohydrates (-saccharides)• Lipids (-fatty acids)• Vitamins, Minerals

Each of the following segments of the GI tract consists of smooth muscle under autonomic nervous control EXCEPT one. Which one is the exception?

A. RectumB. Internal anal sphincterC. Antrum of the stomachD. Upper esophagus

Pellagra, or niacin deficiency, can manifest as all of the following EXCEPT?

A. DermatitisB. DiarrheaC. Dementia D. DeathE. Anemia

Vitamins

Fat-soluble: D- made in skin, pathology=rickets/osteomalaciaA- made from β-carotene, pathology=night blindnessK- made in intestine by bacteria, pathology=bleedingE- from tocopherols=antioxidant, pathology=rare

Water-soluble:C- made from glucose=antioxidant, connective tissue formation

pathology=scurvyB1-thiamine, coenzyme for acetyl-CoA production from pyruvic acid

pathology=BeriberiB2-riboflavin, coenzyme FAD and FMN

pathology=vision problems, cheilosis, glossitisB3-niacin, NAD+ constituent

pathology=pellagraB5-pantothenic acid, coenzyme A function

pathology=loss of appetite, depressionB6-pyridoxine, functions in cellular metabolism

pathology=convulsions, pain, anemiaB12-DNA synthesis (requires Intrinsic Factor from stomach for absorption)

pathology=pernicious anemiaFolic acid-DNA synthesis with Vit. B12, RBC production

pathology=megaloblastic anemia Biotin-urea derivative, coenzyme function in cellular metabolism

pathology=pallor, anorexia, fatigue, alopecia

Ingestion of which of the following MOST markedly decreases gastric emptying?

A. LipidsB. WaterC. MineralsD. Proteins E. Carbohydrates

Cellular MetabolismFats/Lipids…Function?• Membranes, myelin, cholesterol, bile,

steroid hormones, prostaglandins, transport other fats, energy storage, energy 2°.

– Lipogenesis• Anabolism of fats when ATP levels are adequate

or high, or when glucose is high.

– Lipolysis• Catabolism of fats for fuel. When glucose is low,

ketogenesis occurs so the brain can use ketone bodies for fuel, but this results in metabolic ketoacidosis…

Excessive use of fats by the body as a source of energy during starvation or disturbances in carbohydrate metabolism may lead to any of the following conditions EXCEPT

A. KetosisB. AcidosisC. KetonureaD. Alkalosis

Cellular MetabolismProteins/Polypeptides…Function?• Structural, enzymatic, hormonal.

– Proteogenesis• DNA! RNA!Protein• 10 essential amino acids, can’t be synthesized

– Without them you get PEM (kwashiorkor or marasmus), edema (osmotics/oncotics and albumin) and wasting (muscle breakdown)

– Proteolysis• Catabolism of proteins as a final energy source

in cases of malnutrition (wasting, muscle loss and herniation)

Kwashiorkor

Marasmus

⇓serum albumin ! edema signs

Cellular MetabolismCarb’s/Sugars…Function?• Energy/ATP from Glycolysis, Kreb’s, and

ETC!– Gluconeogenesis or Glycogenesis

• Anabolism of glucose (when ATP low) or glycogen (when ATP high) by liver from non-carbohydrate sources, such as lactic acid from muscle waste –such as Cori Cycle in Liver.

– Glycogenolysis• Catabolism of glycogen to glucose for glycolysis by

glucose-6-phosphatase, an enzyme which is found only in liver, kidney and intestinal cells. Occurs when energy/ATP is needed.

A sustained, severe carbohydrate deficiency will result in which of the following?

A. KetoacidosisB. Severe metabolic alkalosisC. A deficiency in prostaglandin formationD. An inability to synthesize ascorbic acid

The catabolism of which of the following results in no energy production in the form of ATP?

A. LipidB. ProteinC. NucleotideD. Carbohydrate

ENDOCRINE SYSTEM

Prolonged medication with cortisol produces atrophy of the adrenal cortex through

A. Inhibition of ACTH productionB. Inhibition of aldosterone secretionC. Direct action on the synthesis of corticoidsD. None of the above

Hypothalamus !

+

Pituitary: FLAT PIG(s)!

+

Adrenals or other target organs - negative feedback

Androgens are produced in the testis and

A. Adrenal cortexB. ThyroidC. Adrenal medullaD. PituitaryE. Hypothalamus

Adrenal Gland

MEDULLA: Catecholamines epinephrine/norepinephrine

CORTEX: (outermost to innermost layers)Zona Glomerulosa: Mineralcorticoids (Aldosterone)Zona Fasciculata: Glucocorticoids (Cortisol)Zona Reticularis: Androgens (Testosterone)

“Three S’s”: Salt, Sugar, Sex

Acromegaly is due to an excessive production of which of the following?

A. ThyrotropinB. GonadotropinC. SomatotropinD. Adrenocorticotropin

Glucosuria with hyperglycemia usually occurs in which of the following?

A. Addison’s diseaseB. Diabetes mellitusC. Cushing’s diseaseD. Parkinson’s disease

In a parathyroid deficiency state, there is

A. An increase in serum calcium and a decrease in serum phosphate

B. A decrease in serum calcium and an increase in serum phosphate

C. An increase in serum calcium and a normal serum phosphate

D. A normal serum calcium and an increase in serum phosphate

PTH=“Break bone” vs. CALCITONIN (from thyroid)=“Build bone”

GENETICS

Central dogma:

DNA ! RNA ! Proteins

Known enzymes and players at each step!

Which of the following types of blotting can be used to identify DNA restriction fragments?

A. EasternB. SouthernC. NorthernD. Western

↑RNA SNOW

←Protein DROP

↓DNA

Which of the following is a pyrimidine base that is present in RNA but is NOT present in DNA?

A. UracilB. GuanineC. ThymineD. AdenineE. Cytosine

CUT the Pie (Pyrimidines)

GA=Purines

If the molar percentage of A (adenine) in a native DNA specimen is 22%, then what is the molar content of G (guanine)?

A. 22%B. 28%C. 44%D. 56%E. 78%

In the DNA molecule, guanine on one strand is joined to cytosine on the complementary strand by which of the following bonds?

A. AmideB. 1 hydrogenC. 2 hydrogenD. 3 hydrogen