General Primary MCQ7

Question 1

The following result in an increase in physiological dead space:

a) positive end-expiratory pressure
b) venous air embolism
c) hypotension
d) pregnancy
e) obesity

Answer 1

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Question 2

Concerning gastric secretion in a normal adult:

a) the lowest pH obtainable in the stomach is about 4.5
b) histamine receptors in the stomach can be pharmacologically stimulated without affecting those in the lungs
c) pentagastrin injection can cause a maximal secretion of acid in the stomach
d) excessive secretion is prevented by an effect originating in the antral receptors
e) gastrin comes mainly from cells in the fundus of the stomach

Answer 2

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Question 3

The resistance of the airways:

a) is not constant in a given subject
b) depends on the pressure drop across the airways
c) is expressed as cm H2O/L/s
d) is greater in turbulent flow than in laminar flow
e) is directly proportional to the density of the gases

Answer 3

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Question 4

In a normal man breathing quietly at rest:

a) carbon dioxide in alveolar air is about twice that in room air
b) carbon dioxide in mixed venous blood is greater than in alveolar air
c) water vapour in alveolar air is less than half that of alveolar carbon dioxide
d) oxygen in expired air is greater than that in alveolar air
e) the amount of nitrogen expired is equal to that inspired

Answer 4

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Question 5

A shift of the oxygen dissociation curve to the right:

a) occurs in the pulmonary capillaries
b) is favoured by a rise in temperature
c) favours the passage of oxygen from blood to tissues
d) occurs when fetal blood is replaced by adult blood
e) occurs in stored blood

Answer 5

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Question 6

Concerning glomerular filtration:

a) glomerular filtration is a type of ultrafiltration
b) glomerular filtrate has the same composition as lymph
c) blood in the efferent arterioles is more viscous than that in afferent arterioles
d) glomerular filtration rate (GFR) is directly proportional to systemic arterial pressure
e) tubular function is more important than GFR in determining the rate of urine production

Answer 6

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Question 7

Concerning local anaesthetics:

a) they are absorbed more rapidly after intercostal block than after caudal administration
b) in the foetus they are able to cross the placenta as readily as from the mother
c) they are weak acids
d) those which are esters are rapidly metabolised by liver enzymes
e) pKa is the pH at which more than half of a local anaesthetic exists in non-ionised form

Answer 7

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Question 8

With reference to the mechanical events in the cardiac cycle in a normal adult human:

a) the left ventricle ejects more blood per beat than the right ventricle
b) the mitral valve opens when the left atrial pressure exceeds the left ventricular pressure
c) during strenuous work, the left ventricular end-diastolic volume may be double that at rest
d) the pulmonary valve opens when the right ventricular pressure reaches 20-25 mmHg
e) during diastole, the left ventricular pressure is about 70 mmHg

Answer 8

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Question 9

Regarding peri-arrest administration of drugs:

a) during ventricular fibrillation, IV access should be established before DC shock is administered
b) the peripheral venous route is prefered because CPR can continue and cannulation is rapid
c) central venous administration delivers drugs more rapidly than peripheral with a 20 ml push
d) in adults, doses of drug for endotracheal administration should be 5 times the IV dose
e) in children, intraosseous drugs should be given when the IV route cannot be established within 90 seconds

Answer 9

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Question 10

With reference to adjustments in exercise:

a) an increase in muscle blood flow begins after the first half minute of exercise
b) cerebral blood flow rises if the exercise causes systolic arterial blood pressure to rise
c) body temperature may rise measurably
d) lymph flow from the exercising muscle increases
e) visceral blood flow decreases

Answer 10

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Question 11

During intra-uterine life:

a) all the foetal blood returning from the placenta flows directly into the inferior vena cava
b) foetal blood carries more oxygen than maternal blood at a low PO2
c) umbilical venous blood has a PO2 of 4-5 kPa
d) blood on the right side of the foetal heart is slightly better oxygenated than that on the left side
e) pulmonary vascular resistance is higher than after birth

Answer 11

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Question 12

The rotameters:

a) are variable orifice flowmeters
b) produce a variable pressure drop across the bobbin
c) produce laminar flow at low flow rates
d) produce laminar flow at high flow rates
e) are accurate to within +/- 0.5%

Answer 12

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Question 13

Cardiac output obtained by the thermodilution technique can be accurate:

a) in the presence of right-sided valvular diseases
b) in the presence of left to right intracardiac shunt
c) in dysrhythmias
d) in the presence of rapid volume infusions
e) if the tip of pulmonary artery catheter is completely wedged

Answer 13

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Question 14

If about 500 ml of isotonic saline were to be infused into a healthy adult, the consequences would include:

a) increase in cardiac stroke volume
b) increase in flow of lymph from peripheral tissues
c) increase in renin secretion by the kidney
d) increase in cerebral blood flow
e) equal distribution of the excess volume between intracellular and extracellular compartments

Answer 14

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Question 15

Regarding carbon dioxide:

a) a rise in PaCO2 may not increase cerebral blood flow
b) PaCO2 greater than 13 kPa could depress the respiratory centre
c) hypercarbia will increase pulmonary vascular resistance
d) chronic hypercarbia results in renal retention of bicarbonate
e) bicarbonate diffuses more quickly than CO2 across the blood-brain barrier

Answer 15

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Question 16

Myocardial contractility:

a) is the degree of inotropic state of heart independent of preload, afterload or heart rate
b) determines the rate of development of ventricular pressure (dp/dt)
c) can be estimated by ventricular pressure-volume loops
d) is reduced by hypocalcaemia
e) accounts for approximately 90% of total myocardial oxygen consumption

Answer 16

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Question 17

The features of non-depolarising blockade include:

a) fasciculation
b) sustained response to tetanic stimulation
c) presence of post-tetanic potentiation
d) small rapidly moving muscles are blocked first
e) more than 90% of the receptors must be blocked by the relaxant for optimal relaxation

Answer 17

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Question 18

Non-depolarising relaxants:

a) can cross the blood-brain barrier
b) may affect the smooth muscles
c) are needed at values of 2-3 times their ED95 for endotracheal intubation
d) can cross tbe placenta
e) are highly ionised at physiological pH

Answer 18

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Question 19

Concerning the chemoreceptors involved in the control of breathing:

a) central chemoreceptors are located on the ventral surface of the medulla
b) raised cerebrospinal fluid hydrogen ion concentration can stimulate central chemoreceptors
c) increased ventilation due to raised arterial PaCO2 is mediated through both central and peripheral chemoreceptors
d) denervation of carotid and aortic bodies can abolish the ventilatory response to hypoxia
e) peripheral chemoreceptors mediate the ventilatory response to acidaemia

Answer 19

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Question 20

Which of the following are competitive antagonists:

a) morphine and naltrexone
b) histamine and perphenazine
c) phenobarbitone and propofol
d) acetyl choline and cisatracurium
e) aspartate and ketamine

Answer 20

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Question 21

Midazolam:

a) is an anticonvulsant
b) is lipid soluble at physiological pH
c) has no active metabolites
d) has an elimination half-life of 2-4 hours
e) can be administered as nasal drops for premedication

Answer 21

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Question 22

The following drugs cross the placenta:

a) midazolam
b) remifentnil
c) propofol
d) sevoflurane
e) ropivacaine

Answer 22

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Question 23

A loading or priming dose:

a) is smaller than the maintenance dose
b) is equal to the amount of drug which is eliminated in a dose interval
c) is unnecessary for benzylpenicillin (t 1/2 30 min)
d) is necessary if a rapid onset of digoxin (t 1/2 36-48 hours) is required
e) is given with the objective of quickly achieving the desired plasma concentration

Answer 23

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Question 24

Bioavailability:

a) is indicated by the area under the plasma concentration-time curve
b) of a drug which is injected intravenously must be less than 100%
c) may be reduced by destruction of drug in the gut
d) may be reduced by metabolism of drug in the liver
e) is greater by sublingual route than enteral route

Answer 24

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Question 25

Regarding interactions between drugs:

a) with steep dose-response curves they are unlikely to be harmful
b) with small therapeutic ratios they are unlikely to be harmful
c) they are described as summation if the effects of two drugs with the same action are additive
d) they are described as potentiation if the action of one drug increases the effect of another
e) the effect of two drugs with similar action is greater in synergism than would have been expected from summation

Answer 25

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Question 26

Alteration of urine pH:

a) with probenecid reduces elimination of penicillin and can be therapeutically useful
b) can significantly affect the elimination of drugs which do not possess ionisable chemical groups
c) is valuable in overdose with barbiturates
d) with alkali is useful in detecting amphetamine addicts since it increases urinary excretion of the drug
e) is of major importance in the management of pethidine overdose

Answer 26

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Question 27

Elderly patients show increased response to standard drug dosage and an increased incidence of adverse drug reactions because they have:

a) increased lean body mass
b) reduced renal and hepatic function
c) reduced blood flow to vital organs
d) better nutrition
e) less efficient homeostatic mechanisms

Answer 27

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Question 28

Regarding diffusion:

a) the rate of diffusion of a substance across a membrane is proportional to its concentration gradient
b) the diffusion across the alveolo-capillary membrane is measured using carbon monoxide
c) the rate of the diffusion of a gas is proportional to its tension gradient
d) pneumonectomy approximately halves the diffusing capacity
e) the rate of diffusion of a gas is inversely proportional to the square root of its molecular weight

Answer 28

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Question 29

The following are idiosyncratic reactions:

a) haemolysis after exposure to NSAIDs in patients with glucose-6-phosphate deficiency
b) prolonged apnoea after suxamethonium due to abnormal pseudocholinesterase
c) malignant hyperpyrexia after halothane
d) acute porphyria following induction with thiopentone
e) sulphonamide toxicity in slow acetylators

Answer 29

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Question 30

Phenytoin:

a) plasma half-life is the same at all plasma concentrations
b) is subject only to first-order kinetics
c) enhances its own metabolism
d) is unlikely to cause drug interactions in a patient taking other medications
e) has a remarkably small range of adverse effect

Answer 30

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