General Primary MCQ5

Question 1

Regarding central venous pressure monitoring:

a) the tip of the catheter must be in the right atrium
b) cannon a waves are seen in presence of junctional rhythm
c) y descent is due to opening of the tricuspid valve
d) x descent occurs during ventricular systole
e) a wave corresponds with QRS complex in ECG

Answer 1

FFTTF

Question 2

Adrenaline:

a) should be administered every 3 minutes during CPR
b) is principally released in postsynaptic sympathetic nerve endings
c) differs from noradrenaline by having an extra methyl group
d) is commonly used with local anaesthetics at a concentration of 1:80,000
e) d-adrenaline is 50-100 times less potent than l-adrenaline

Answer 2

TFTTT

Question 3

Low molecular weight heparins:

a) have a molecular weight <10,000 daltons
b) inhibit activated factors IX, X, XI, XII
c) include tinzaparin, dalteparin and enoxaparin
d) are not effective in deep-vein thrombosis prophylaxis in once-daily regimen
e) do not bind to thrombin and antithrombin III simultaneously

Answer 3

TTTFT

Question 4

The following drugs have antiplatelet activity:

a) epoprostenol
b) calcium heparin
c) hydroxyethyl starch
d) dipyridamole
e) remifentanil

Answer 4

TTTTF

Question 5

Compared with that of a normal adult, the newborn infant’s:

a) kidneys have less ability to excrete a concentrated urine
b) blood-brain barrier is less permeable to bilirubin
c) heat regulation is more efficient because of its ability to metabolise brown fat
d) blood has a greater affinity for oxygen at low oxygen pressures
e) carbohydrate reserve is greater

Answer 5

TFFTF

Question 6

Concerning acid-base balance:

a) standard bicarbonate is lower than actual bicarbonate in a chronic obstructive airways disease (COAD) patient
b) metabolic alkalosis is seen with prolonged use of loop diuretics
c) standard bicarbonate is low in metabolic acidosis
d) about 70% of carbon dioxide is transported in plasma as bicarbonate
e) the ratio of HCO3/CO2 may be normal in a stable COAD patient

Answer 6

TTTTT

Question 7

The following statements are true regarding cardiovascular physiology:

a) atrial systole contributes to 25% of ventricular filling
b) pericardial effusion decreases end-diastolic volume
c) coronary blood flow is about 5% of the cardiac output at rest
d) the pressure-volume loop consists of isovolumetric contraction, ejection, isovolumetric relaxation and rapid ventricular filling
e) LVdP/dTmax is dependent on changes in preload

Answer 7

TTTTT

Question 8

In the human heart:

a) end-systolic left ventricular volume is dependent on the afterload
b) left ventricular static compliance is reduced in myocardial ischaemia
c) ejection fraction is the ratio of stroke volume to end-diastolic volume
d) the second heart sound coincides with end of the T wave in the ECG
e) pulmonary artery occlusion pressure reflects the left ventricular end-diastolic pressure

Answer 8

TTTTT

Question 9

When measuring arterial blood pressure with a sphygmomanometer:

a) cuff width should be 20% greater than the arm diameter
b) a mercury column manometer may be used at an angle of up to 25 degrees from vertical
c) a common source of error is blockage of the air vent
d) there are five Korotkoff phases
e) use of a finger to detect return of pulsation is highly inaccurate

Answer 9

TFTTF

Question 10

In the human thyroid gland:

a) iodide ions from the plasma enter the follicle cells by passive diffusion
b) T4 and T3 bind to the receptors in nuclei
c) thyroxine, once synthesised, is then coupled to thyroglobulin until released
d) a greater proportion of tri-iodothyronine is formed when iodine is deficient
e) thyroid hormones increase the number and affinity of beta-receptors in the myocardium

Answer 10

FTTTT

Question 11

Regarding aldosterone:

a) it increases the amount of Na+-K+ ATPase in the target cells
b) it reduces the sodium content of the sweat
c) it increases the acidity of the urine
d) it increases the potassium content of the urine
e) basal secretion is normal even after hypophysectomy

Answer 11

TTTTT

Question 12

Regarding insulin:

a) its release is increased by the sulphonylurea type of hypoglycaemic drugs
b) it has a half-life of 5 minutes in the circulation
c) it increases the number of glucose transporters in the plasma membrane
d) secretion is reduced by surgical stress response
e) it is normally secreted at a rate of about 40-50 U/day

Answer 12

TTTTT

Question 13

The following statements about end-tidal CO2 are true:

a) normal variation in barometric pressure at sea level is unlikely to influence end-tidal CO2
b) rebreathing can raise end-tidal CO2 if the minute ventilation remains unchanged
c) a decrease in cardiac output decreases the end-tidal CO2
d) discontinuation of N2O at the end of anaesthesia may transiently reduce the end-tidal CO2
e) shunt has less of an impact on end-tidal CO2 in contrast to O2

Answer 13

TTTTT

Question 14

A high level of calcium in the blood:

a) is associated with an increased excitability of muscle and nerve cells
b) may result from chronic renal failure
c) may result from excessive vitamin D ingestion
d) is seen after accidental hyperparathyroidectomy
e) is seen following injection of gland extracts from the anterior pituitary

Answer 14

FFTFT

• Since calcium blocks sodium channels and inhibits depolarization of nerve and muscle fibers, increased calcium raises the threshold for depolarizatio

Question 15

Cardiac muscle contraction:

a) develops greater tension when initial fibre length is reduced
b) occurs with a greater velocity of shortening when the load on the muscle is small
c) develops variable force depending on the frequency of contractions
d) reaches its peak at the end of the repolarisation phase of the action potential
e) occurs in a graded manner due to fibre recruitment

Answer 15

FFTFF

Question 16

PaCO2-EtCO2 gradient:

a) is up to 0.7 kPa in patients without significant disease
b) increases in venous air embolism
c) is greater in high frequency ventilation
d) is greater in high V/Q areas of the lungs
e) is greater in patients with rapid respiratory rates

Answer 16

TTTTT

Question 17

In a normal resting man, a fall in heart rate would be expected to occur following:

a) increased carotid sinus pressure
b) increased right atrial pressure
c) application of pressure to the eyeball
d) the release of a Valsalva manoeuvre
e) inspiration

Answer 17

TTTTF

Question 18

Which of the following are true:

a) the [H+] electrode relies for its action on the hydrogen ion sensitivity of a glass electrode
b) A CO2 electrode is, in principle, a modified [H+] electrode
c) The [H+] electrode requires no temperature compensation
d) CO2 may be measured by an infrared absorption spectrometer
e) N2O may be measured by an infrared absorption spectrometer

Answer 18

TTFTT

Question 19

The capnograph trace:

a) plots CO2 on the X-axis versus time on the Y-axis
b) elevated phase I is due to rebreathing of CO2
c) a flattened upstroke of phase II represents slow exhalation secondary to obstruction
d) phase III shows a flat curve with a slight upstroke
e) undulations in phase III may be due to cardiac oscillations

Answer 19

FTTTT

Question 20

In the adult human:

a) albumin is synthesised only in the liver
b) elevated serum lactate dehydrogenase is a good indicator of liver damage
c) plasma urea concentration may be low in hepatic failure
d) plasma fibrinogen is synthesised in the liver
e) the pressure in portal vein is normally about 2 kPa

Answer 20

TFTTT

Question 21

Regarding suxamethonium myalgia:

a) it is more common in women
b) it commonly occurs in day case patients
c) a rise in plasma creatinine phosphokinase and myoglobin is related to the severity of muscle pain
d) the severity of muscle pain is related to strength of muscle fasciculations
e) intravenous lidocaine before suxamethonium may completely abolish the muscle pain

Answer 21

TTFFF

Question 22

Regarding the renin-angiotensin-aldosterone mechanism:

a) renin is secreted by the juxtaglomerular apparatus
b) the physiological role of aldosterone is to maintain plasma volume and plasma sodium levels
c) angiotensin II maintains the tone of the efferent arterioles of the glomeruli
d) angiotensin II is the primary factor determining plasma aldosterone levels
e) beta- blockers inhibit renin release

Answer 22

TTTTT

Question 23

According to European Guidelines for Basic Life Support:

a) when the pulse is absent, the first thing to do is to go and telephone for help
b) the recovery position should be adopted when patient is unconscious and breathing through a clear airway
c) ventricular fibrillation is the commonest primary cause of cardiac arrest
d) early defibrillation is the most important determinant of success in ventricular fibrillation
e) the peripheral venous route is preferred because CPR can continue and cannulation is rapid

Answer 23

FTTTT

Question 24

Adenosine:

a) is composed of adenine and d-ribose
b) causes depression of cardiac contractility by binding to adenosine A1 receptors
c) mediates vasodilatation by binding to low affinity adenosine A2 receptors
d) is used in diagnosis of supraventricular arrhythmias
e) blocks re-entry circuits for its antiarrhythmic effects

Answer 24

TTTTT

Question 25

Concerning the renal buffering mechanism:

a) H+ excreted into the tubular fluid reacts with HCO3- in the tubular fluid
b) H+ excreted into tubular fluid combines with HPO42- when HCO3- is consumed
c) H+ excreted into the tubular fluid reacts with NH3 when HPO42- is consumed
d) the phosphate and ammonia buffers are more utilised than HCO3 in metabolic acidosis
e) an increased amount of HCO3- is added to blood in respiratory acidosis

Answer 25

TTTTT

Question 26

Total body oxygen consumption can be measured by the following methods:

a) oxygen loss from a closed breathing system
b) subtraction of expired from inspired volume of oxygen
c) ventilated hood technique
d) multiplying cardiac output by arterial-mixed venous oxygen content difference
e) tissue PO2 electrodes

Answer 26

TTTTF

Question 27

Pulmonary surfactant:

a) is produced by type II pneumocytes
b) is a mixture of phospholipids and proteins
c) prevents transudation of fluid from the blood into the alveoli
d) lies in a monomolecular layer
e) lowers surface tension to a large extent in a small alveolus

Answer 27

TTTTT

Question 28

Regarding mivacurium:

a) it releases more histamine than atracurium in equipotent doses
b) it is broken down by plasma cholinesterase as rapidly as suxamethonium
c) it is a bisquaternary benzylisoquinolinium compound
d) 10% of a bolus dose is excreted in the urine over 24 hours
e) at an equipotent dose it has a similar onset of action to pancuronium

Answer 28

TFTTT

Question 29

Pulmonary vascular resistance:

a) is normally 150-250 dyne.sec/cm5
b) when raised decreases the left ventricular pre-load
c) is increased at an arterial PO2 of 6 kPa
d) is increased by application of positive end-expiratory pressure
e) is decreased by nitric oxide inhalation

Answer 29

FTTTT