Paper 4 MCQs

Question 1

The following act by blocking cholinergic receptors:

a) trimetaphan
b) hexamethonium
c) ouabain
d) benzhexol
e) physostigmine

Answer 1

TTFTF

Question 2

Esmolol:

a) has a negative inotropic effect
b) has no intrinsic sympathomimetic activity
c) causes a dose-dependent fall in heart rate
d) increases airways resistance
e) may prolong the duration of action of suxamethonium

Answer 2

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Question 3

Enflurane:

a) is a halogenated methyl-ethyl ether
b) has a blood/gas solubility coefficient of 1.43
c) lowers intracranial pressure
d) increases the tone of the pregnant uterus
e) causes a decrease in systemic vascular resistance

Answer 3

TFFFT

Question 4

Morphine:

a) causes histamine release
b) has no active metabolites
c) undergoes extensive first-pass hepatic metabolism
d) has an elimination half-life of 3-4 hours
e) may be antagonised by pentazocine

Answer 4

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Question 5

Uterine tone is:

a) increased by ketamine
b) decreased by halothane
c) increased by beta-2 antagonists
d) unaffected by suxamethonium
e) decreased by nifedipine

Answer 5

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Question 6

Aspirin overdose causes:

a) thrombocytopenia
b) coma
c) metabolic acidosis
d) jaundice
e) pulmonary oedema

Question 7

Non-depolarising neuromuscular blockers are potentiated by:

a) lithium
b) trimetaphan
c) diazepam
d) magnesium
e) suxamethonium

Answer 7

TFTTT

Question 8

Atropine:

a) crosses the blood/brain barrier
b) can cause an initial bradycardia
c) increases the rate of gastric emptying
d) increases conduction through the A-V node
e) produces bronchoconstriction

Answer 8

TTFTF

Question 9

Hepatotoxicity has been associated with:

a) diethyl ether
b) chloroform
c) cyclopropane
d) enflurane
e) halothane

Answer 9

FTFTT

Question 10

The anticoagulant effect of warfarin:

a) is exerted directly on the blood
b) is slow in onset
c) can be reversed by vitamin K
d) is potentiated by phenylbutazone
e) is potentiated by barbiturates

Answer 10

FTTTF

Question 11

The following may be used in the treatment of digoxin toxicity:

a) propranolol
b) lidocaine
c) phenytoin
d) calcium
e) potassium

Answer 11

TTTFT

Question 12

Dobutamine:

a) is structurally similar to isoprenaline
b) activates adenyl cyclase
c) has a selective action on beta-1 adrenoreceptors
d) has a half-life of 2 minutes
e) increases the left ventricular end diastolic pressure

Answer 12

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Question 13

Organophosphorus anticholinesterases:

a) have an irreversible action
b) phosphorylate cholinesterase
c) produce more inhibition of acetyl cholinesterase than of plasma cholinesterase
d) can have their action reversed in the early stages by atropine
e) are readily absorbed through the skin

Answer 13

TTFTT

Question 14

The following factors encourage passage of a substance across the cell membrane:

a) high lipid solubility
b) low concentration gradient
c) high molecular weight
d) negative hydrostatic pressure
e) high degree of ionisation

Answer 14

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Question 15

Amitriptyline in overdose causes:

a) cardiac arrhythmias
b) hypertension
c) restlessness
d) metabolic acidosis
e) jaundice

Answer 15

TFTTF

Question 16

Low plasma cholinesterase activity:

a) is related to the patient’s blood group
b) has no effect on the action of decamethonium
c) occurs with organophosphorus poisoning
d) prolongs the action of esmolol
e) occurs in malnutrition

Answer 16

FFTFT

Question 17

Sulphonylureas:

a) act by increasing insulin release
b) tend to produce weight loss
c) are suitable for use in pregnancy
d) are effective in correcting ketoacidosis
e) can produce hypoglycaemia

Answer 17

TFFFT

Question 18

Side-effects of hydralazine include:

a) tachycardia
b) impotence
c) constipation
d) systemic lupus erythematosus
e) bronchoconstriction

Answer 18

TTFTF

Question 19

The following are measures of scatter in statistical analysis:

a) mean
b) standard error of the mean
c) standard deviation
d) range
e) p of less than 0.5

Answer 19

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Question 20

Statistical tests are used to:

a) eliminate observer bias
b) eliminate placebo effect
c) show that results are true
d) show that the results did not occur by chance
e) show that the results are clinically significant

Answer 20

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Question 21

The liver:

a) receives most of its oxygen supply from the portal vein
b) has its highest oxygen tension at the centre of a lobule
c) produces heparin
d) has a normal portal venous pressure of greater than 20 mmHg
e) receives approximately 25% of the cardiac output

Answer 21

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Question 22

Skeletal muscle blood flow:

a) increases with norepinephrine
b) receives 50% of the cardiac output at rest
c) may cease during isometric contraction
d) increases with rhythmic contraction
e) increases with epinephrine

Answer 22

FFTTT

Question 23

In thermoregulation:

a) respiratory heat loss is insignificant under normal conditions
b) brown fat is an important source of heat production in neonates
c) shivering is due to impulses conducted via autonomic efferents
d) peripheral vasoconstriction increases heat production
e) sweating is mediated by sympathetic adrenergic neurones

Answer 23

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Question 24

Epinephrine:

a) is synthesised by demethylation of norepinephrine
b) increases coronary blood flow
c) increases free fatty acids in the blood
d) mobilises glycogen stores from the liver
e) is metabolised in the plasma by monoamine oxidase

Answer 24

FTTTF

Question 25

Glucagon:

a) is a positive inotrope
b) is produced by the B cells of the pancreas
c) stimulates production of free fatty acids in the blood
d) release is increased in starvation
e) stimulates glycogen synthesis

Answer 25

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Question 26

Surfactant:

a) is a mucopolypeptide
b) causes a decrease in surface tension
c) results in the same surface tension for different sized alveoli
d) causes an increase in compliance
e) production is reduced after a prolonged reduction in pulmonary blood flow

Answer 26

FTFFT

Question 27

Sinus arrhythmia:

a) produces a lengthening of the P-R interval
b) produces a lengthening of the R-R interval
c) is maximal with breath holding
d) is more marked during exercise
e) is more marked in 70 year olds than in 20 year olds

Answer 27

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Question 28

A pressure-volume curve can be used for measuring:

a) the work of breathing
b) functional residual capacity
c) anatomical dead space
d) compliance
e) respiratory quotient

Answer 28

TFFTF

Question 29

The absolute refractory period for cardiac muscle is:

a) as long as the entire action potential
b) the period when no further action potential can be stimulated
c) twice the length of the S-T interval
d) as long as the mechanical contraction
e) shorter for pacemaker tissue than for normal cardiac muscle

Answer 29

FTFFT

Question 30

In a young normal adult:

a) the glomerular filtration rate is approximately 125 ml/min
b) the 24 hour urine creatinine content is approximately 800 mg
c) urine specific gravity is always less than 1000
d) renal blood flow is approximately 20% of cardiac output
e) over 50% of water reabsorption from the glomerular filtrate occurs in the collecting ducts

Answer 30

TFFTF

Question 31

Total plasma calcium:

a) increases with phosphate
b) increases with a rise in albumin
c) changes its degree of ionisation with pH changes
d) is decreased in osteoporosis
e) is affected by vitamin D

Answer 31

FTTFT

Question 32

There is increased intestinal motility with:

a) increased intraluminal pressure
b) anticholinesterase drugs
c) sympathetic block to T4
d) stimulation of the splanchnic nerves
e) increased circulating epinephrine

Answer 32

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Question 33

In a normal resting subject, a bradycardia would be expected following:

a) an increase in carotid sinus pressure
b) an increase in right atrial pressure
c) application of pressure to the eyeball
d) the release of a Valsalva manoevre
e) inspiration

Answer 33

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Question 34

The velocity of conduction of a nerve action potential:

a) is inversely related to the cross-sectional area of the axon
b) is faster in a myelinated fibre than in an unmyelinated one
c) is decreased by cooling the nerve
d) can exceed 100 m/s in humans
e) is highest in pre-ganglionic autonomic fibres

Answer 34

FTTTF

Question 35

The placenta:

a) transports glucose from maternal to fetal blood by facilitated diffusion
b) can synthesise glycogen
c) actively transports oxygen from maternal to fetal blood
d) allows protein molecules to pass from maternal to fetal blood by pinocytosis
e) secretes oestradiol

Answer 35

TFFTT

Question 36

Oxytocin:

a) stimulates production of milk
b) stimulates ejection of milk
c) release is stimulated by dilatation of the cervix
d) is synthesised in the anterior pituitary
e) produces more powerful uterine contraction in the presence of progesterone

Answer 36

FTTFF

Question 37

Aldosterone:

a) production increases with a fall in plasma osmolality
b) production decreases with a fall in blood volume
c) production decreases with a rise in plasma renin level
d) increases urinary potassium excretion
e) may be produced by tumours of the adrenal cortex

Answer 37

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