General Primary MCQ1

Question 1

Regarding two compartment pharmacokinetics:

a) a drug is always removed from the peripheral compartment
b) the central compartment is blood volume
c) a drug with a high volume of distribution is likely to be lipophillic
d) a drug can have a short duration of action while being eliminated very slowly
e) most anaesthetic drugs are modelled well with a two-compartment model

Answer 1

FFTTT

Question 2

Desflurane:

a) is a fluorinated methylisopropyl ether
b) boils at 23 degrees C
c) is safe to use in patients with malignant hyperpyrexia
d) stimulates the sympathetic system when inspired concentration is suddenly increased
e) prolongs the duration of muscle relaxants

Answer 2

FTFTT

Question 3

Regarding the use of suxamethonium:

a) bradycardia is a complication
b) phase II block occurs more commonly with neonates
c) prolonged duration of action may be seen in around one patient in 40
d) can raise the serum potassium by 0.5 mmol/ L
e) dose required is lower in small children

Answer 3

TFFTF

Question 4

Concerning electroencephalography (EEG):

a) voltages are in the range of 10-100 millivolts
b) spontaneous EEG activity is lost when the body temperature drops below 25 degrees C
c) b waves are enhanced by sedatives
d) d waves only occur in brain injury
e) q waves occur at a frequency of 4-7 Hz

Answer 4

FFTFT

Question 5

Action potentials:

a) are all or none signals of about 100 mV in amplitude
b) are generated by leakage of K+ down their concentration gradient
c) are normally conducted antidromically
d) summate at high frequencies
e) depend on the size of the stimulus

Answer 5

TFFFF

Question 6

Conduction velocity of a nerve impulse:

a) is greater in C fibres than in group A fibres
b) is greater in large diameter nerve fibres
c) is greater in unmyelinated nerve fibres because of saltatory conduction
d) can be as fast as 120 m/s in human nerve fibres
e) is decreased in hypothermia

Answer 6

FTFTT

Question 7

Regarding drug metabolism by cytochrome P450 isoenzymes:

a) cytochrome P450 makes up 1% of total liver proteins
b) the most important enzyme is CYP3A4
c) the system is responsible for most of the reductive metabolism in humans
d) volatile anaesthetics are metabolised by CYP2E1
e) some isoenzymes are inhibited strongly by erythromycin

Answer 7

TTFTT

Question 8

Atropine:

a) may cause bradycardia
b) dilates the pupil in premedicant dose
c) has a shorter duration of action than glycopyrrolate
d) increases the physiological dead space
e) has both muscarinic and nicotinic effects

Answer 8

TTTTF

Question 9

In the pulmonary circulation:

a) capillary hydrostatic pressure is about 25 mmHg
b) 50% of the cardiac output goes to the pulmonary circulation in the foetus
c) angiotensin is broken down
d) bradykinin is inactivated
e) hypoxia causes vasoconstriction

Answer 9

FFTTT

Question 10

Regarding local anaesthetic agents (LA):

a) the potency of LAs is proportional to their lipid solubility
b) the duration of action is dependent on protein binding
c) agents with low pKa have a faster onset of action
d) all local anaesthetics are vasodilators
e) the depth of local anaesthetic block is increased by increasing the dose

Answer 10

TTTFT

Question 11

Cisatracurium besylate:

a) is a mixture of three stereoisomers
b) in equipotent doses has a similar duration of action to vecuronium
c) is less potent than atracurium
d) undergoes more Hoffmans degradation than atracurium
e) in equipotent doses has a similar onset time to atracurium

Answer 11

FTFTF

• 4-5x more potent than atracurium
• slower than atracurium

Question 12

If an electric current is fed through the body:

a) risk of injury is largely dependent upon the current flow
b) antistatic shoes provide good protection due to their high resistance
c) high frequencies are more dangerous than low frequencies
d) ventricular fibrillation occurs at a lower current in patients with dysrhythmias
e) a tingling sensation is felt at a current strength of 1 mA

Answer 12

TTFTT

Question 13

The countercurrent concentrating mechanism in the kidney:

a) depends on active transport of sodium and chloride out of the ascending loop of Henle
b) allows an osmolality of 1200 mosmoles/kg in distal tubules
c) occurs predominantly in the cortical nephrons
d) relies on the free movement of water and electrolytes across the walls of the vasa recta
e) depends on a low concentration of urea in the medullary interstitium

Answer 13

TFFTF

Question 14

The adverse effects of NSAIDs on the kidney:

a) are reversible in normal kidneys
b) are not dose related
c) are mediated by inhibition of PGI2 synthesis
d) may cause acute interstitial nephritis
e) are counteracted by the use of ACE inhibitors

Answer 14

TFTTF

Question 15

The following trigger the secretion of antidiuretic hormone from the posterior hypothalamus:

a) a 5% reduction in extracellular fluid
b) chronic renal failure
c) anxiety
d) supine position
e) head injury

Answer 15

FFTFT

Question 16

Concerning the measurement of oxygen:

a) an oxygen electrode should be calibrated at zero and in room air
b) oxygen tension in a liquid can be measured with a Clark electrode
c) a polarographic electrode can be used in vivo
d) oxygen measurement in a gas mixture makes use of the magnetic property of oxygen
e) a fuel cell has a rapid response to change in oxygen concentration

Answer 16

FTTTF

Question 17

Drug clearance:

a) is the amount of drug removed from plasma in unit time
b) is proportional to half-life
c) is low in lipid-soluble drugs
d) occurs only in the liver and kidney
e) is calculated by dividing the dose of drug given by area under plasma concentration-time curve

Answer 17

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Question 18

The volume of distribution of a drug:

a) is low if the drug is highly protein bound
b) can be calculated by multiplying half-life by natural logarithm of 2
c) is relatively low for muscle relaxants
d) is proportional to half life
e) is dependent on the elimination rate constant

Answer 18

FFTTF

Question 19

Concerning composition of body fluids:

a) plasma constitutes a quarter of extracellular fluid (ECF) volume
b) ECF volume may be grossly depleted in intestinal obstruction
c) the protein content of interstitial fluid is higher compared with intracellular fluid (ICF) and plasma
d) the ratio of ECF/ICF volume is smaller in infants and children
e) the normal osmolality of plasma is 280 mosmoles/kg

Answer 19

TTFFT

Question 20

Aldosterone causes:

a) a decrease in urine sodium concentration
b) weight gain
c) decreased serum chloride level
d) increased extracellular fluid volume
e) increased K+ excretion

Answer 20

TTFTT

Question 21

The following antibiotics have good activity against anaerobic bacteria:

a) vancomycin
b) aztreonam
c) metronidazole
d) imipenem
e) trimethoprim

Answer 21

FFTTF

Question 22

Flumazenil:

a) may induce panic attacks in susceptible patients
b) has anticonvulsant activity in patients with epilepsy
c) has a long duration of action
d) may cause nausea and vomiting
e) has inverse agonist action at benzodiazepine receptors

Answer 22

TFFTF

• competitive inhibitor of benzodiazepines but also exhibits weak partial agonism of GABA_A receptor complexes

Question 23

Concerning the blood brain barrier (BBB):

a) it is virtually impermeable to ions and proteins
b) it breaks down around brain infarcts
c) a rise in serum albumin by 20 g/L will draw more H2O across the BBB than a rise in serum Na+ by 5 mmol/L
d) when damaged, cytotoxic brain oedema results
e) mannitol crosses the BBB easily

Answer 23

TTFFF

Question 24

Osmolality:

a) is the number of osmotically active particles per litre of solvent
b) of urine is similar to that of plasma in chronic renal failure
c) may be estimated by formula 2X(Na+K) + Blood sug + BUN
d) is measured by amount of depression of the freezing point
e) is a part of colloid oncotic pressure

Answer 24

FTFTF

Question 25

ABO compatibility is essential for transfusion of:

a) SAGM blood
b) haemoglobin solutions
c) cryoprecipitates
d) FFP
e) platelets

Answer 25

TFTTF

Question 26

The following increase during pregnancy:

a) plasma volume
b) fibrinogen
c) gastric emptying time
d) glucose tolerance
e) arterial PaCO2

Answer 26

TTTTF

Question 27

Carbon monoxide:

a) binds to haemoglobin with 100 times the affinity of oxygen
b) results in the oxyhaemoglobin curve shifting to the left
c) poisoning can be reliably detected by pulse oximetry
d) levels in normal non-smokers is 10-15%
e) concentration in circle is increased during desflurane anaesthesia

Answer 27

FTFFT

Question 28

Resting potential across the nerve membrane:

a) depends largely on the ratio of K+ inside and outside the cell
b) is positive inside with respect to outside
c) is of the order of 0.06 volt
d) decreases in magnitude during prolonged hypoxia
e) is greater the larger the diameter of the nerve fibre

Answer 28

TFTTF

Question 29

Activation of NMDA receptors:

a) is important in learning and memory
b) can result in neuronal damage
c) is involved in the development of opioid tolerance
d) causes opening of the chloride channel
e) may increase the intensity of pain

Answer 29

TTFFT

Question 30

Bacteria develop resistance to antibiotics:

a) by changing permeability of porin channels in cell wall
b) by producing enzymes to inactivate antibiotics
c) by altering target sites (DNA gyrase and topoisomerase) for antibiotics
d) by active extrusion of antibiotic once it enter the cell
e) easily in presence of necrotic tissue

Answer 30

TTTFT