General Flashcards
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
FFTTT
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
FTFTT
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
TFFTF
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
FFTFT
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
TFFFF
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
FTFTT
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
TTFTT
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
TTTTF
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
FFTTT
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
TTTFT
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
FTFTF
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
TTFTT
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
TFFTF
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
TFTTF
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
FFTFT