General Primary MCQ4

Question 1

Severe hyperkalaemia is suggested by:

a) absent p waves in the ECG
b) chronic ACE inhibitor intake
c) decreased serum bicarbonate level
d) suxamethonium administration in immediate burn
e) aldosterone deficiency

Answer 1

TTTFT

Question 2

Glycine:

a) is a non-essential amino acid
b) can be used as an irrigating solution in transurethral resection of the prostate
c) acts as an inhibitory neurotransmitter in the spinal cord
d) toxicity can cause permanent blindness
e) solution is highly ionised

Answer 2

TTTFF

Question 3

Regarding pH and ionic dissociation:

a) a weak acid will be 1000 times more ionised at a pH of 7 than at a pH of 4
b) a strong alkali will have a high pH
c) the pH is inversely proportional to the hydrogen ion concentration
d) a pH of 7.7 corresponds to a hydrogen ion concentration of 20 nmol/ L
e) in the adult, there is a hundred fold range of H+ concentration that is compatible with life

Answer 3

TTFTF

Question 4

Regarding 5-hydroxytryptamine (5-HT):

a) it is synthesised from L-tryptophan in the enterochromaffin cells
b) it is metabolised to hydroxyindole acetic acid
c) it causes bronchospasm and vasodilatation by interacting with 5HT-2 receptors
d) a 5HT-3 antagonist is a good anti-emetic
e) it may have a platelet aggregating effect

Answer 4

TTTTT

Question 5

Rocuronium:

a) is an aminosteroid
b) is stable in aqueous solution
c) undergoes principally hepatic elimination
d) can provide intubating conditions within 60 seconds
e) does not release histamine

Answer 5

TTTTT

Question 6

Propofol:

a) is insoluble in water
b) is bound to albumin up to 97-98%
c) reduces sodium channel opening times in neuronal membranes
d) is isotonic
e) does not cause tachycardia

Answer 6

TTTTT

Question 7

S(+) ketamine compared with R(-) ketamine:

a) is 3-4 times more potent
b) is associated with less incidence of emergence reaction
c) is a better analgesic
d) has a faster recovery
e) has a higher affinity for NMDA receptors

Answer 7

TTTTT

Question 8

Concerning the physiology of the stomach:

a) acid secretion in response to hypoglycaemia is mediated by gastrin
b) gastric emptying is quickened by sympathetic stimulation
c) acid secretion is mediated by H2, M1 and gastrin receptors
d) gastric pH is normally around 2-3
e) acidity is reduced by proton pump inhibitors

Answer 8

TFTTT

Question 9

The ratio of intravascular hydrostatic pressure to colloid hydrostatic pressure (according to Starling’s Forces) is greater:

a) in splanchnic capillaries than in renal glomerular capillaries
b) than normal in hepatic failure
c) than normal in haemorrhagic shock
d) than normal in capillaries where the oedema is due to venous obstruction
e) in systemic than in pulmonary capillaries

Answer 9

FTFTT

Question 10

The effects of moving from sea level to an altitude of 5000 m include:

a) increased alveolar ventilation due to central chemoreceptor stimulation
b) increased blood bicarbonate level
c) reduced exercise tolerance
d) alveolar PO2 nearly reaches PO2 of air
e) increased plasma volume

Answer 10

FFTFF

Question 11

An environmental temperature of 40 degrees C:

a) is thermoneutral if there is a strong wind
b) leads to vasodilatation of skin vessels
c) results in heat stroke if the relative humidity is 100%
d) causes the body to sweat with a lower sodium concentration
e) is appropriate for people in training for heat adaptation

Answer 11

FTTTT

Question 12

Longer term adjustments to altitude hypoxia include:

a) hyperventilation
b) kidneys slowly lose bicarbonate
c) increased serum level of erythropoietin
d) increased number of mitochondria
e) heart rate remains elevated

Answer 12

TTTTT

Question 13

Concerning patterns of stimulation for monitoring of neuromuscular junction:

a) 100 Hz tetanic stimulation is commonly used
b) frequency of train of four is 2 Hz
c) first response of train of four is equivalent to single twitch response
d) train of ratio of 0.7 corresponds to 100% recovery of single twitch
e) double burst stimulation consists of two short tetanic stimulations separated by 750 ms

Answer 13

TTTTT

Question 14

Non-depolarising muscle relaxants:

a) demonstrate fade due to their presynaptic action
b) may not show post-tetanic facilitation
c) with large dose may block the diaphragm first before adductor pollicis
d) have onset defined as time from administration to abolition of response to single twitch

Answer 14

TFTT

Question 15

The sequence of events in muscle contraction:

a) action potential depolarises the T-tubules
b) depolarisation of T-tubules release calcium from sarcoplasmic reticulum
c) calcium binds to the troponin-tropomyosin complex
d) actin combines with myosin ATP leading to cross-bridge activation
e) calcium moves back into the sarcoplasmic reticulum by passive transport

Answer 15

TTTTF

Question 16

Morphine:

a) 10-30% of oral morphine reaches the systemic circulation
b) has a terminal half-life of approximately 3 hours
c) has morphine-3-glucoronide as principal metabolite
d) morphine-6-glucoronide has no analgesic effect
e) increases the secretion of antidiuretic hormone

Answer 16

TTTFT

Question 17

Amiodarone:

a) blocks the potassium channels
b) prolongs the refractory period of myocardium and entire conducting tissues
c) has a elimination half-life of approximately 28 days
d) may result in pulmonary fibrosis on prolonged use
e) may cause hypothyroidism

Answer 17

TTTTT

Question 18

Regarding the pharmacokinetics of volatile agents:

a) blood/gas partition coefficient of desflurane is 0.69
b) sevoflurane can be used for inhalational induction in adults
c) inspired concentration influences the rate at which alveolar concentration is attained
d) alveolar concentration during recovery decreases more slowly after prolonged anaesthesia

Answer 18

FTTT

Question 19

Breathing (reservoir) bags:

a) are designed to distend enormously when subjected to pressures above 50-60 mmHg
b) are of optimal size that fits neatly in one hand
c) prevent wastage of fresh gas flow during expiratory pause
d) provide a rough visual assessment of volume of ventilation
e) act as a reservoir because anaesthetic machine can not provide the peak inspiratory flow required in normal respiration

Answer 19

FFTTT

Question 20

Regarding breathing systems used in anaesthesia:

a) Magill system is most efficient for spontaneously breathing patients even at a fresh gas flow (FGF) of 70% of minute ventilation
b) D, E and F systems are all T pieces
c) Bain system requires a FGF of 50-60 ml/kg during spontaneous breathing
d) the rate of change of vapour concentration in circle system depends on circle system volume, the FGF rate and net gas uptake
e) Magill system is inefficient during controlled ventilation because much of the gases are vented via pop-off valve

Answer 20

TTFTF

Question 21

A typical motoneurone:

a) innervates only one skeletal muscle cell
b) has a myelinated axon
c) would have its cell body only in the ventral horn of the spinal cord
d) might itself receive an input directly from Ia afferent fibres in the spinal cord
e) would be stimulated by application of glycine to its cell body

Answer 21

FTTTF

Question 22

The following are statements about acetylcholine:

a) its synthesis requires ATP
b) it is broken down in the synaptic cleft by choline acetyltransferase
c) it is broken down to acetic acid and choline
d) it is released only by preganglionic autonomic fibres
e) it acts by diffusing through channels in the postsynaptic membrane

Answer 22

TFTFF

Question 23

The velocity of conduction of a nerve action potential:

a) is inversely proportional to the cross-sectional area of the axon
b) is faster in a myelinated fibre than in a non-myelinated fibre of the same diameter
c) is decreased by cooling the nerve
d) may be 200-250 ms in the fastest conducting mammalian fibres
e) is decreased by disease which attack the myelin sheath

Answer 23

FTTFT

Question 24

An excitatory post-synaptic potential (EPSP):

a) is itself propagated by the post-synaptic cell
b) comprises depolarisation of the membrane to zero, transient reversal of potential and then repolarisation
c) is related in amplitude to the concentration of the initiating transmitter at the presynaptic membrane
d) may summate both temporally and spatially with other EPSPs
e) is reduced in amplitude by drugs which block the post-synaptic receptors for the transmitter substance

Answer 24

FTTTT

Question 25

C fibres transmitting pain sensation:

a) conduct at an average velocity of 2 metres/second
b) conduct temperature sensation
c) terminate in laminae 2 and 3 of the dorsal horn
d) are the sole nociceptive afferents from viscera in the chest and abdomen

Answer 25

FTTF

Question 26

Concerning CNS physiology:

a) the dominant cerebral hemisphere is most commonly the left
b) REM sleep occurs for about 25% of the time during normal sleep in adults
c) the dominant cerebral hemisphere is always on the right in left-handed individuals
d) REM sleep is associated with a marked increase in muscle tone
e) Neuromuscular block reduces the amplitude of somatosensory evoked potential

Answer 26

TTFFF

Question 27

In the myocardium:

a) a rise in extracellular K+ brings resting the membrane potential towards threshold
b) a rise in extracellular K+ increases the membrane permeability to K+
c) hypokalaemia results in reduced ventricular action potential duration
d) the slope of depolarisation (dp/dt) affects the contractility of ventricular muscle fibres
e) a rise in extracellular Na+ increases membrane resting potential

Answer 27

TTTTF

Question 28

Fibrinogen depletion:

a) is diagnostic of disseminated intravascular coagulation
b) occurs as a consequence of increased fibrinolysis
c) should be treated by administration of cryoprecipitate
d) may be a consequence of vitamin K deficiency
e) occurs more commonly in men than in women

Answer 28

FTTFF

Question 29

Insulin:

a) is secreted by the alpha cells of the pancreas
b) is anabolic
c) has a circulating half-life of 5 minutes
d) shows increased secretion during surgery
e) can be used for rapid control of hyperkalaemia

Answer 29

FTTFT

Question 30

Concerning absorption of carbon dioxide in breathing systems:

a) soda lime granules are sized 4-8 mesh
b) baralyme contains calcium hydroxide in addition to barium hydroxide
c) soda lime produces more compound A during low fresh gas flow
d) dry soda lime absorbs more carbon dioxide
e) carbon dioxide first reacts with sodium and potassium hydroxide of soda lime

Answer 30

TTTFT