Primary MCQs-July2009

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Primary Physiology Black Bank | Primary Pharmacology Black Bank


Primary MCQ papers

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log dose response curve

a. is linear between 20-80% of response
b. linear between 20-80% of dose

there was a graph showing 2 log-dose response curves, x and y. one with Ed50 at 2, the other at 16, it said the relative potency x to y is

etc etc

volume of distribution

a.for a large water soluble drug like mannitol is equivalent to total body water 0.6L/kg
b.for highly protein bound, large molecules, like heparin is 0.04L/kg more important for the infusion rate than the loading dose

A large volume of distribution is important (can't remember exact wording):

a. when calculating loading dose
b. when calculating maintenance dose

Repeat (see GP28) - Drug has hepatic extraction ratio of 0.7, 30% absorbed, what is it's bioavailability:

d. 0.21
e. 0.09

Adverse effect of 8.4% Na bicarbonate administration (can't remember exact wording or if a pharmacology or physiology MCQ):

a. Acidosis
b. intracellular acidosis
c. rebound metabolic alkalosis upon stopping insusion
d. Hyperkalaemia

Aspirin causes:

a. hypothermia due to antipyretic effect
b. hyperglycaemia due to increased glucose use by peripheral tissue
c. ?DIC
d. respiratory and metabolic acidosis

LD 50 is:

a. mean lethal dose
b. something about a graded response
c. calculated by giving animals increasing doses of a drug until they die
d. something related to probit and standard deviation and 5 probit units
e. another option about the probit

There was a question on Malignant Hyperthermia but can't remember exact wording:

a. tachyphylaxis with suxamethonium infusion
e. ?

General Anaesthetics - Inhalational


a. has a higher MW than enflurane
b. has a lower BP than enflurane

The volatile anaesthetic agent least metabolized is:

a. Desflurane
b. Sevoflurane
c. Isoflurane
d. Nitrous oxide
e. Xenon

General Anaesthetics - Intravenous


a. has direct negative inotropy
b.decreases intracranial pressure
c.causes bronchoconstriction
d. ?

Local Anaesthetics

Ropivacaine more cardiotoxic than bupivacaine

b. produces more motor block than bupivacaine



e. has similar physicochemical properties to bupivacaine

Muscle Relaxants & Antagonists

vecuronium more lipid soluble than pancuronium a benzolisoquinolinium structure a bisquaternary amine structure




a.dissociates quickly from the nAChR

b.tachyphylaxis at the onset of MH highly protein bound

  • new* The best test of reversal of non depolarising neuromuscular blockade in an AWAKE subject is

a. TOF count of 4

b. No fade double burst suppression

c. No fade tetany 200Hz

d. ? e. ? NB did not mention any clinical measures like head lift etc

Major Analgesics/Opioids

Alfentanil has a fast onset because

a. it is 90% unionised in plasma

b. it has a heptanol partition coefficient of 1800

c. its t1/2 keo is less than 3 mins

d. (something else wrong)

e. all of the above

codeine a good analgesic IV de-methylated in the liver

c.maximal efficacy at 30mg



  • new* Methadone

a. half life increases with repeated dosing

b. has active metabolites




  • new* Oxycodone

a elimination half life is 4 hours






to treat central anticholinergic syndrome






Psychotherapeutic Drugs

droperidol causes all except: a.long QT b.sedation c.antiemesis d. e.dysphoria

  • new* Marijuana

a. Is poorly lipid soluble

b. Either said dependence producing or may cause withdrawal syndrome

c. Acts of specific cannabanoid receptors in the CNS

d. ?

e. ?

Cardiovascular Drugs

regarding the structure of catecholamines:

a.alpha carbon substitution confers beta selectivity

b.beta carbon hydroxylation confers receptor affinity

c.l-dopa is an agonist at alpha


e. d-dobutamine has alpha 1 agonist activity and l-dobutamine has alpha 1 antagonist activity (or other way round, can't remember exactly)

Sodium nitroprusside, sign of toxicity:

a. tachyphylaxis

b. decreased mixed venous O2

c. decreased arterial PO2



Endocrine Drugs


a. acts via beta adrenergic receptors useful in chronic hypoglycaemia

c.increases gastric motility

d.increases catecholamine release


Miscellaneous Drugs

Magnesium Toxicity occurs at plasma levels of

  • A. 1.0-2.0mcg/L
  • B. 2.0-3.0 mcg/L
  • c. 3.0-4.0mcg/L
  • D. 4.0-5.0mcg/L
  • E >5.0mcg/L

Statistics & Drug Trials

ld50 the mean lethal dose

b.animals are given drug until they die

c.this is a graded response curve


e.something about a linear response

1000 people have an epidural the mean is 4.4cm with a sd of .3cm (repeat)

a.68% will be within 4.1 and 4.7cm






Unclassified Physiology

Add to this section if don't have time to classify & organise your remembered MCQs

Vasomotor centre:

a. Depressed by hypoxia

b. has afferents from skeletal muscle

c. decrease sympathetic output with increased BP (i thought it was increased sns output, which made the question harder)

d. located at C1 area of medulla


Answer C presuming wording is correct. If C reads.... increased SNS output with increased BP .... then B next best answer. Reference Ganong Ed 21 pg 608 Table 31-4

  • I disagree. I think the question may have read "increased SNS output" which makes C incorrect.
  • The RVLM is the vasomotor centre = C1 region of medulla -> D correct (from"the rostral ventrolateral medulla (RVLM) is the dominant source of excitatory drive to the barosensitive class of sympathetic efferent under anaesthesia. Its role is assumed, but not proved, to be equally dominant in the awake state. The RVLM input originates from a neurochemically heterogeneous collection of glutamatergic neurons, a large subset (70%) of which also synthesize adrenaline. These are called C1 neurons" - Guyenet in Nature Reviews Neuroscience 7, 335-346 (May 2006)

General physiology

Regarding NaKATPase:

a. stimulated by high extracellular sodium levels

b. stimulated by ouabain

c. electrogenic pump

Mineral essential for function of lactate dehydrogenase and all other peptidases is

a. Magnesium

b. manganese

c. copper

d. zinc

e. ?selenium

FE06 Gibbs-Donan equilibrium

a. explains the distribution of diffusable ions between intravascular and extravascular space
b. effects distribution of plasma proteins across capillary membrane
c. effects distribution of proteins across cell membrane
d. explains the distribution intracellular and extracellular ions
e. explains the distribution of non-diffusable ions across cell membrane
  • I don't remember the options quite being like this
    • I agree - was definitely only one option with the word 'diffusible' in it, option e was not there

Alt version: Gibbs-Donnan (can't remember wording):

A. membrane potential
B. intravascular and extravascular ions
C. intracellular and extracellular ions
D. ?
E. ?

  • Repeat*

In the presence of hyposmolarity and significant hypovolaemia

b. water permeability of collecting ducts in increased
c. aldosterone decreased
e. none of the above

Fluid & electrolytes

Hypokalaemia (2.5 mM/l):

a. shorten PR interval leading to tachyarrhythmias

b. lengthen QT interval

c. no effect on T wave

d. depresses ST segment

e. widen QRS complex

Laminar Flow of Newtonian fluid is inversely proportionate to

a. pressure gradient
b. ?radius or ?diameter
c. density
d. length
  • viscosity was not in the options*

The therapeutic Magnesium levels for management of pre-eclampsia is

a. 1-1.5mmol/L
b. 2-3 mmol/L
c. 4-6 mmol/L
d. 6-8 mmol/L
e. 8-10 mmol/L

[According to the Royal Women's Hospital protocol plasma levels of 1.7 to 3.5 should be aimed for] [Ref:]

Acid-base physiology

At pH 7.4, the H+ concentration is

A. 40 ummol/L
B. 40 mmol/L
C. 40 nmol/L
D. 40 mg/L
E. 40 ng/L

Phosphate (PO4) is a good intracellular buffer and tubular buffer because

a. PKa is similar to intracellular pH
b. intracellular concentration of PO4 higher
c. tubular fluid concentration of PO4 higher
d. Urine usually more acidic
e. all of above

Addition of H+ to the following

H+ + (HPO4)2- = H2PO4-

a. ?
b. increase in conjugate base
e. decrease [HPO4-2]

Respiratory Physiology

Intra-alveolar pressure at mid-inspiration in normal healthy person

A. -1 cmH2O
B. 0 cm H2O
C. ?

(I don't remember this question being asked)

  • I don't remember this question either!
  • Answer A - J.B.West 7th Edition page 109

Differences between the apex and the base of the lung

a Transmural pressure is greater
b less negative intrathoracic pressure at the apex
c V/Q ratio is lower at apex
d alveoli are smaller at apex

Answer (A)

A-a gradient of 50mmHg in person breathing room air could be

a normal
b due to venous admixture
c Due to hypoventilation
d Low cardiac output
e None of above

Answer (B)

CO (Carbon Monoxide) is diffusion limited because

a.CO rapidly equilibrates
b.CO is so small that only a defect in diffusion could hinder it
c.CO is so soluble that only a defect in diffusion could hinder it
d. is a large molecule and has ?trouble crossing membrane
e PaCO can be assumed as zero

Answer (C)

RE16 Arterial-venous difference in CO2 content

a. 2ml/100ml
b. 4ml/100ml
c. 8ml/100ml or 16ml/100ml
d. 48ml/100ml
e. 52ml/100ml

Answer (C) - PaCO2 = 35-45mmHg, PvCO2 - 42-52mmHg (typical A-V difference = 6-8mmHg)

I think its B = referring to CO2 content not pCO2 - CO2 content arterial blood = 48 ml CO2/100 ml blood - CO2 content venous blood = 52 ml CO2/100 ml blood

Partial pressure of oxygen in mixed venous blood of a person breathing 100% oxygen

a 50 mmHg
b 80 mmHg
c number higher than 80
d number higher than c
e number higher than d

answer a, nunn's 6th edition p349

RE17 Vasoactive substance inactivated through passage in lung:

a. Angiotensin 1
c. bradykinin
d. adrenaline

RE34 Oxygen toxicity:

a. CNS effects if 100% O2 for 24 hrs
b. Resp effects if FiO2>30% O2 for 24 hrs
c. both pulmonary and CNS toxicity at 760 mmHg
e. CNS effects only if PO2 significantly higher than 760 mmHg

nunn's 6th edition p357

RE34b Oxygen toxicity:

a. due to lung absorption atelectasis
b. CNS effects
d. lipid peroxidation

Increased parasympathetic stimulation of the respiratory tract causes

a. change in the static compliance

RE61 Static compliance is affected by (i think this was roughly the wording):

b. airway resistance
c. surface tension

CVS physiology

  • repeat*

Which one of following causes an increase in heart rate?

a. Bainbridge reflex

b. Carotid chemoreflex

c. Bezold-Jarisch reflex

d. Cushing reflex

  • Repeat*

Relating heart to circulation

a. sympathetic stimulation shifts cardiac function curve to the right

b. arteriolar dilatation will increase CVP when all other variables are fixed

c. increased blood volume shift cardiac function curve to right

d. hypervolaemia can correct heart failure

e. Vasoconstriction shift vascular function curve to left

Answer (B) - (A), (C) shifts curve to left, (E) shifts curve to right, (D) is strange because whilst the body aims to conserve volume to increase preload and therefore SV, hypervolaemia is NOT a treatment per se of heart failure (in fact we use diuresis as a management to correct pulmonary and peripheral oedema) - so I don't know what they mean be 'correct' in this context.

CV Effect of isometric contraction of skeletal muscle

A. systolic BP decreases

B. pulsepressure widens

C diastolic BP decreases

D. diastolic pressure increases

E. steady decrease in stroke volume

Which one of the following caused arteriolar vasoconstriction

a. nitric oxide

b. neuropeptide Y

c. substance P


e. alkalosis

Most important determinant of long term BP control is


b. blood volume

c. total peripheral resistant

d. stroke volume

e. total body water

Action potential in myelinated axon

A. absolute refractory period less than one millisecond

B. Na channels close when membrane potential becomes zero

C. duration is 5-10 seconds



Fastest propagation of action potential occurs in:

a. Atrial muscle

b. AV node

c. bundle of His

d. purkinje fibres

e. ventricular muscle

The immediate effect of moving from supine to erect

a.increase in cardiac output


c.increase in CVP

d.increase in pulmonary vascular resistance

e. increase in systemic vascular resistance

Isovolumetric contraction relates best to which part of atrial pressure wave: *repeat*

a. a wave

b. c wave

c. x descent

d. v wave

e. y descent

Renal physiology

Glomerular-tubular balance relates to:

a. reabsorption is proportional to filtered load




e. none of the above

Glycosuria is most likely to occur if:

a. both GFR and plasma glucose level increase

b. GFR increases but plasma glucose remains same

c. plasma glucose increased but GFR remains same

d. both GFR and plasma glucose decrease


Which one of the following increase tubular reaborption of salt and water



c. increase oncotic pressure of peritubular capillaries

d. increase hydrostatic pressure of peritubular capillaries

Response to significant hypovolaemia and decreased plasma osmolality:

a. increased urine output

b. decreased urine output




GI physiology

Regarding bilirubin:

a. all bilirubin produced from haemoglobin

b. bilirubin produced in reticuloendothelial system

c. stercobilinogen excreted in kidneys

d. bilirubin is conjugated in the liver and secreted into the blood

e. conjugated bilirubin is responsible for total blirubin measured in blood

Ganong 22nd pg 502

  • (A) "Most"
  • (B) "formed in the tissues"
  • (C) "urobilinogens enter the general circulation and are excreted in the urine"
  • (D) Some is but the majority into bile canaliculi by active transport
  • (E) Total = conjugated + free bilirubin

So once again straight out of Ganong. D is most correct

An alternative view of the above - correct answer (B). Power and Kam (2Ed, Pg. 211) notes that haem is broken down in the reticuloendothelial system, particularly the spleen. 85% of this is derived from the haem moeity of haemoglobin, whilst the remainder comes from haem containing compounds (cytochrome P450, respiratory chain transporters, etc.). No mention is made in this text of bilirubin secretion into the bloodstream.

Blood & immunology

1 unit fresh frozen plasma:

a. contains anticoagulant

b. contains all coag factors except V and VIII

c. needs to be crossmatched

d. does not contain albumin

e. does not contribute to oncotic pressure once transfused

  • Repeat* Erythropoietin

a. stimulates production of both red and white cells

b. plasma concentration is inversely proportionate to haematocrit

c. something wrong

d. inactivated in kidney

e. half life several minutes

  • Repeat* Concerning fixed tissue macrophages


b. activated by lymphokines from T cells

c. engulf and kill bacteria with lymhokines

d. absent in lungs and liver


Endocrine & metabolic physiology

Which is NOT produced in citric acid cycle:

a. CO2

b. H+


d. NAD

e. FADH2

Per cycle of CAC-> 2 x CO2, 3 x H+, 3 x NADH, 1 x FADH2 -> No NAD (this is a high energy molecule) ANSWER (D) Source Mr Kreb


a.are produced in the mitochondria

b.action ceased by both enzyme and non-enzyme actions

c.are released at the synapse by the release of Acetylcholine in both sympathetic and parasympathetic nerves.

d.half life of 50-60 seconds.

e.10% conjugated and renal excretion


The C fibers that enter the dorsal root terminate

A Laminae I & II

B I & IV


D IV & V


Answer A. Reference Ganong Ed 21 pg 139

  • repeat*

Regarding glial cells


b. Something about Schwann cells

c. Oligodendrocytes form myelin in CNS neurons

d. Something about astrocytes


Answer C. Reference Ganong Ed 21 pg 51. Oligodendrocytes produce myelin in CNS, Schwann cells produce myelin in peripheral nervous system

Regarding cerebrospinal fluid:

a. Produced at a rate of 150ml/day

b. absorption is fixed amount daily

c. produced by choroid plexus and ependymal surfaces of all ventricles

d. total volume 350mL


Answer C. Reference Ganong Ed 21 pg 615

Physiology of muscle & NMJ

In the Resting State the permeability of the cell membrane to ions is







Immediate source of energy in muscles:

a. ATP in all muscles

b. creatine phosphate in smooth, ATP in cardiac and skeletal

c. creatine phosphate in smooth and skeletal, ATP in cardiac

d. creatine phosphate in skeletal, ATP in smooth, cardiac

e. creatine phosphate in all

T tubules in cardiac muscle enter at:

a. m line

b. Z line

c. h band

d. i band

e. a band

see [1] - cardiac has one t tubule per sarcomere (at z disc), skeletal has 2 (at A-I band) - put in comments once MCQ code assigned

Maternal, foetal & neonatal physiology

Increase in maternal ventilation

a. to do with oestrogen

b. to do with progesterone

c. Present by second trimester

d. mostly due to increased respiratory rate


Foetal circulation all true except:

a. systemic venous blood saturation is 26%

b. Oygen saturation of umbilical vein is 67%

c. ductus venosus drains into IVC

d. 75% of foetal cardiac output goes to placenta

e. pressure is higher in pulmonary artery than aorta

  • (A) Ganong 22nd Ed pg 628 - 26%
  • (B) Same reference -> 80%
  • (C) Obviously true
  • (D) Same reference -> 55% of foetal cardiac output goes through placenta
  • (E) Also obvious: > Paorta and therefore blood is shunted through ductus arteriosus

So (as remembered), all are true except (B) and (D)

Clinical measurement

CM38 Raman Scattering is

a. the wavelength remains unchanged

b. is a type of mass spectroscopy


d. measures type of gas only

e. measures the concentration of a gas

Which one of the following is a linear change

A. oxygen tension vs alveolar ventilation

B. CO2 tension vs alveolar ventilation

C. partial pressure of oxygen along tissue capillary

D. partial pressure of carbon dioxide along tissue capillary

E. malignant growth

Answer B. Reference Nunns Ed 6 pg 465

    • Repeat*

When measuring cardiac output by thermodilution technique, which of the following affect least on accuracy

a. rapid injection of cold saline

b. injection during inspiration




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