Primary MCQs-March2009

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Primary Physiology Black Bank | Primary Pharmacology Black Bank


Primary MCQ papers

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GP30 With regard to LD50:

A. Is the mean lethal dose in animals
B. Something about probit’s relation to standard deviation
C. Animals are given increasing doses of a drug until they die
D.  ?
E. Something about log concentration being plotted against something using probits to linearize the data for humans

GP04b Rectal administration of drugs:

A. Administration in the lower third (below the dentate line) completely avoids hepatic first pass
B. Is rapid due to the anastomoses between the superior and inferior haemorrhoid plexuses
C. Provides reliable absorption
D. ?
E. None of the above

General Anaesthetics - Inhalational

  • New*

Regarding sevoflurane, desflurane and isoflurane

A. Isoflurane has the highest saturated vapour pressure
B. All three cause increase in cerebral blood flow and raised ICP
C. Sevoflurane is decomposed to carbon monoxide
D. ?
E. All three can be delivered via a variable bypass temperature compensated something vaporizer

Which ONE of the following is NOT TRUE regarding halothane hepatitis?

A. There is no cross sensitivity between inhalational agents
B. Sporadic cases reported with sevoflurane
C. Antibody formation against an antigen
D. Trifluoroacetic acid is most commonly implicated
E. All of the above

General Anaesthetics - Intravenous

  • New*

Concentration of thiopentone in the brain 5 minutes after a single bolus injection

A. 2%
B. 5%
C. 20%
D. 50%
E. 100%

Answer D. 50% stoelting pg 129 "the brain receives about 10% of the total dose of thipental in the first 30 to 40 seconds. the maximal brain concentration is followed by a decrease over the next five minutes to one half the initial peak concentration, due to redistribution of the drug from the brain to the other tissues." this is assuming the question is talking about concentration, as opposed to percentage of the original dose.

Was this question talking about absolute concentration, or change from the peak level? If it was change from peak level, 50% sounds reasonable. However, if talking about absolute concentration, there are surely many variables (albumin, blood pH) that determine levels. Also, values that give amounts for "Vessel Rich groups" obviously include heart, liver etc, thus 50% would seem a little high...

  • New*

Propofol more suitable for TIVA compared to thiopentone because of

A. Higher clearance
B. Smaller volume of distribution
C. Shorter T1/2 Keo
D. ?

  • New*

Addition of another substance to propofol is not advisable because

A. Increases allergenicity of propofol
B. Suphydryl group gets sepearated from the phenol moiety
C. Causes disruption of lipid micelles
D. Changes osmolality of the solution
E. ?

Local Anaesthetics

LA22 Mar09Levobupivacaine is different from bupivacaine in:

A. Increased hydrophobicity of the aromatic ring
B. Increased hydrophilicity of amine group
C. Addition of a methyl group to the hydrophilic amine ring
D. ?
E. ?

LA23 Mar09 A toxic dose of bupivacaine is given and results in seizure and ventricular fibrillation. Which is most correct in order of priority:

A. Amiodarone, diazepam, ventilate with 100% O2, defibrillation
B. Ventilate with 100% O2, external cardiac compressions, diazepam, defibrillation
C. Diazepam, defibrillation, vetilate with 100% oxygen, cardiac compression
D. Ventilate with 100% oxygen, defibrillate, external cardiac compressions, adrenaline
E. External cardiac compressions, defibrillation, amiodarone, ventilate with 100% oxygen

LA24 Mar09 Cocaine

A. Overdose rarely causes convulsions
B. Central effects are due to high dopamine levels
C. Metabolism is dependent on plasma pseudocholinesterase
D. ?
E. ?

Muscle Relaxants & Antagonists

  • New*

The drug which prolongs neuromuscular blockade without affecting the activity of pseudocholinesterase

A. Neostigmine
B. Metoclopramide
C. Magnesium
D. Cyclophosphamide
E. Organophosphates
  • New*

Tetanic fade after a dose of depolarizing neuromuscular relaxant is suggestive of:

A. ?
B. Decreased release of acetycholine from the presynaptic membrane
C. Phase II block
D. Prior administration of a nondepolarizing neuromuscular blocker
E. ?

With regard to drugs acting at the NMJ:

A. Botulinum toxin binds to the 2 alpha subunits of the ACh receptor
B. Gentamicin inhibits Ca++ influx required for exocytosis
C. Suxamethonium dissociates extremely rapidly from the ACh receptor
D. Mg++ inhibits binding of Ach to the receptor
E. Hemicholinium inhibits Ach release from the nerve terminal

Major Analgesics/Opioids

  • New*

Tramadol at serotonin receptor best described as

A. Agonist

B. Indirect agonist

C. Inverse agonist

D. Agonist-antagonist

E. Partial agonist

  • New*

Opioid receptors for analgesia

A. Spinal

B. Supraspinal

C. Periphery

D. Spinal and supraspinal

E. All of the above

  • New*

With regards to COX-II inhibitors

A. Parecoxib is a prodrug

B. Parecoxib has a half-life of 6 to 8 hours

C. Valdecoxib is converted to a metabolite which is a selective COX-II inhibitor

D. Valdecoxib can cause life-threatening skin reactions

E. All of the above

  • New*

Pethidine A. Synthetic compound

B. Primarily excreted renally

C. Inhibits uptake of noradrenaline

D. Something about comparison with morphine with regard to nausea and vomiting

  • New*


A. Less protein bound than salicylic acid

B. ?

C. Half-life 6-8 hours

D. Displaces warfarin from protein binding sites

E. Must be converted to salicylic acid before activity


  • New*

Atropine and glycopyrrolate

A. Both are naturally occuring

B. Both can cause initial bradycardia after IV administration

C. Glycopyrrolate increases oxidative metabolism



Psychotherapeutic Drugs

Cardiovascular Drugs

CD54 Pharmacokinetics of amiodarone:

A. Oral bioavailability is reliable

B. Doses must be reduced in renal and hepatic failure

C. Omission of 1 or 2 doses can lead to severe consequences

D. Metabolism is via ?hydroxylation/demethylation?

E. Increases/decreases refractory period

CD55 Sympathomimetics:

A. Phenylephrine acts only on alpha receptors

B. Metaraminol acts only on alpha receptors

C. Methoxamine in high doses acts on beta receptors

D. Pseudoephedrine is an isomer of ephedrine

E. ?

CD56 Whice ONE of the following is True about vasopressin?

A. Slowly metabolized by renal peptidase

B. Does not cause coronary vasoconstriction

C. Causes mesenteric vasoconstriction

D. Increases plasma level of factor VIII

E. Is an orally active derivative of ADH

CD57 Clonidine:

A. Dry mouth and agitation are very common side effects

B. Half life is 24-48 hours

C. ?

D. Can cause severe hypertension if withdrawn abruptly after long term therapy with large doses

E. Therapeutic dose is 2-5mg per day

CD58 Beta adrenergic receptor antagonists

A. Seldom causes inhibition of lipolyisis

B. Causes inhibition of gluconeogenesis caused by adrenergic stimulation following hypoglycaemia

C. Does not mask the signs of hypoglycaemia

D Sudden cessation is not associated with rebound effects

E. There is no evidence of cardiac protection for high risk patients pre-operatively

CD59 Labetalol:

A. Beta and alpha antagomisn with partial agonist activity at alpha 2 receptors

B. Beta and alpha 1 antagonist

C. Alpha agonist and beta 1 antagonist

CD60 GTN is helpful myocardial infarction by:

A. Decreasing left ventricular pressure and mean arteriolar pressure

B. Producing methaemoglobinaemia

C. improving coronary blood flow by dilating the small arterioles

D. ?

CD61 Which of the following could cause significant adverse reactions with the MAO-i selegiline?

A. Dopamine

B. Phenylephrine

C. Ephedrine

D. Metaraminol

E. Nove of the above

Endocrine Drugs

Miscellaneous Drugs


A. Structurally related to procainamide and may have anti-arrhythmic activity at high doses

B. Something about metabolism

CD62 Mannitol:

A. Causes loss of medullary tonicity

B. Urine hyperosmolar compared to plasma

C. Site of action is PCT and DCT

D. Tubular fluid is isotonic in descending loop of Henle

  • New* Oxazepam is a metabolite of

A. Diazepam

B. Lorazepam

C. Midazolam

D. Temazepam

E. Flunitrazepam

  • New*


A. release from endothelium stimulated by SNP

B. Not released by shear stress on endothelium

C. Acts by cyclic AMP to cause vasodilatation

  • New*


A. Therapeutic dose is 1.5-3mg/kg

B. Decreases prolactin secretion

C. Increases intestinal motility by its action on H1 receptors

D. Is effective in reversing GIT effects of opioids

E. Has identical central and peripheral effects as cisapride

Statistics & Drug Trials

There were 2 questions (1 new, 1 old) about ED50/LD50


Unclassified Physiology

Add to this section if don't have time to classify & organise
your remembered MCQs

General physiology

  • New*


A. Is a dimer

B. Transports 3 potassium in and 2 sodium out

C. Activated by cellular dehydration

D. ?

E. Digoxin binds to the potassium binding portion

  • New*

Regarding protein synthesis and DNA

A. Introns are the DNA transcription sites

B. Promoter region

C. Something about DNA gyrase

D. Something about RNA translation (wrong)

E. DNA replication arises from a single mRNA strand

Fluid & electrolytes

  • new*

17. In the resting state, the cell membrane permeability to Na:K is

A. 100:1

B. 10:1

C. 1:1

D. 1:10

E. 1:100

Significant hypovolaemia in the presence of decreased plasma osmolality results in:

A. increased urine output

B. increased permeability of collecting duct to water

C. decreased aldosterone secretion

D. decreased renin secretion

E. none of the above

Acid-base physiology

Respiratory Physiology

Carbon dioxide tension is highest in which gas sample?

A. Alveolar dead space
B. End tidal
C. Ideal alveolar
D. Mixed expiratory
E. Anatomical dead space

Carbon dioxide is carried most in the body in the form of

A. Dissolved in blood
B. Carbamino compounds in RBC
C. Carbamino compounds in plasma
D Bicarbonate in RBC
E. Bicarbonate in plasma

Answer E. West Ed 7 pg 81

Most likely physiological cause of hypoxaemia after intra-abdominal surgery:

B. Diffusion hypoxia
C. Metabolic acidosis
D. Increased physiological dead space
E. Increased shunt

Most likely changes in a previously healthy 60 year old male who has morphine overdose in room air

A. pO2 pCO2 60 pH 7.51 HCO3 25 BE -1
B. pO2 60 pCO2 50 pH 7.26 HCO3 26 BE-1
C. pO2 pCO2 25 pH HCO3 BE-1
D. pO2 pCO2 25 pH HCO3 BE+8
E. pO2 pCO2 15 pH 7.35 HCO3 BE -12

RE61Static lung compliance

A. Is change in pressure per unit volume
B. Affected by airway resistance
C. Is equal to pulmonary elastance
D. Depends upon surface tension forces
E. Combination of lung and chest wall compliance

Application of 10cmH20 of pressure at the upper airway of a spontaneously breathing person will cause

A. Decreased airway resistance
B. Increased V/Q mismatch
C. ?
D. ?

Answer A. Nunn's Ed 6 pg 44

When breathing 100% oxygen, the mixed venous oxygen saturation is

A. 25%
B. 50%
C. 75%
D. 85%
E. 100%

Nunn's Ed 6 table 26.1 ... 100% O2 causes a rise in venous O2 content from 14.3 to 16.3 ml/dL. No figure for sats but would expect a small rise from 75% to maybe 85%. Hence I feel D is the best answer

Hypoxic pulmonary vasoconstriction

A. Is due to decreased oxygen saturation in arterial blood
B. Is due to decreased oxygen tension in bronchial circulation
C. Inhibited by metabolic alkalosis
D. Inhibited by respiratory alkalosis
E. Is associated with increased V/Q mismatch

Answer D. Nunn's Ed 6 pg 102..... Alkalosis, whether respiratory or metabolic in origin, causes pulmonary vasodilatation and reduces or even abolishes HPV Which is why I thought C and D are correct or one of them should read Acidosis

The following is true for true for mixed venous carbon dioxide

A. CO2 content is 42mls/100ml blood
B. Most carried in dissolve form
C. Most carried in carbamino form.
E. Causes increased haematocrit

CO2 content = ~54ml/dL in mixed venous blood (Nunns 5th Ed pg 227) B and C obviously wrong E is correct albeit poorly worded

CVS physiology

  • New*

With regard to the connection between the heart and the circulation:

A. When arteriolar resistance increases, total systemic blood pressure decreases.

B. With constant cardiac output, decrease in systemic vascular resistance is associated with increase in CVP

C. With transfusion of volume, the vascular curve will shift left and the cardiac output curve will shift right

D. With sympathetic stimulation the cardiac output curve will shift right.

E. Hypervolaemia is the treatment for cardiac failure

Answer B


Pulse pressure increases all except

A. Increased aortic compliance

B. Decreased diastolic pressure

C. Increasing heart rate

D. Increased systolic pressure

E. Decreased systemic resistance

Answer A

  • New*

Normal pulmonary artery pressure

A. 10/0 mmHg

B. 15/5 mmHg

C. 25/10 mmHg

D. 45/15 mmHg

E. 120/80mmHg

  • New*

True about carotid sinus:

A. Located at the origin of the external carotid artery

B. Increased firing in response to increased blood pressure

C. Decreases central sympathetic outflow by inhibiting medullary vasomotor centre

D. Do not respond to something

E. Responds to pressure rather than stretch

  • New*

True about regular exercise

A. Maximal heart rate is increased

B. ?

C. During moderate exercise, total systemic vascular resistance increases

D. During moderate exercise, systemic blood pressure increases


  • New*

Cardiac action potential in SA node

A. Vagal stimulation causes depolarisation

B. Something about potassium channels being responsible for phase 0

C. Long term calcium channels cause depolarizing potential

D. Calcium channels are cause of action potention, no role of sodium channels

E. Long term calcium channels cause action potential

  • New*

T-tubules in cardiac cells located in:

A. Z line

B. M line

C. A-I band junction

D. A-H band junction

E. I line

Answer A : see

  • new*

Mild to moderate blood loss in a healthy 70kg 30 year-old male:

A. Decreased renin and aldosterone


C. Does not cause decrease in systemic blood pressure

D. Does not cause cardiac and cerebral vasoconstriction


  • New*

Isometric contraction

A. Force of contraction independent of the initial fibre length

B. Force of contractionis independent of initial load

C. Velocity of contraction is independent of load

D. Not associated with decreased fibre length? Z-Z length?


  • New*

Left ventricular compliance


B. Is directly proportional to elastance

  • New*

Left coronary perfusion is least during

A. Tachycardia

B. Ventricular systole

C. Hypotension



Renal physiology

  • New*

Renal circulation


B Renal O2 consumption is higher than cardiac by mls/100g/min

C. Renal circulation has the highest resistance in the body

D. Renal medulla has higher oxygen supply than cortex

E. Renal oxygen consumption is proportional to sodium transport

  • New*

Osmotic diuresis

A. Causes sodium loss

B. Washes out medullary concentration gradient

C. Increases afferent arteriole pressure

D. Increases blood flow to the cortex

E. All of the above

The ascending limb of the Loop of Henle:

A. is permeable to water

B. Active transport of K+ into the lumen

C. Active transport of water into the lumen

D. Active transport of Cl- out of the lumen

E. Active transport of Na+ into the lumen

Glomerulotubular balance refers to:

A. the proportionate reabsorption of filtered load

B. the maintenace of iso-osmolality between glomerular filtrate and fluid in the proximal tubule.

C. The proprtionate urine output relative to GFR

D. the maintenace of equal Na+ concentration in glomerular filtrate and proximal tubule

E. None of the above.

GI physiology

  • New*

Liver synthesizes all but

A. vWF

B. Prothrombin

C. Antithrombin III

D. Fibrinogen

E. Albumin

Answer A. Reference Brandis pg 197, vWF synthesised by endothelial cells and megakaryocytes

Blood & immunology

  • new*


A. Derived from circulating lymphocytes

B. Half life of less than 24 hours

C. First line of defence against bacterial infection

D. Not present in CNS

E. Called histiocytes in liver

Endocrine & metabolic physiology

Repeat How many hours post eating to measure BMR?


As a person moves from hyperalert state to sleep, EEG waves change:

A. alpha -> delta -> beta -> theta

B. a -> b -> d -> t

C. b -> t -> d -> a

D. b -> a -> t -> d

E. t -> d -> b -> a

Comparison of EEG bands

  • Beta (12–30 Hz)
  1. symmetrical distribution, most evident frontally; low amplitude waves
  2. alert/working
  3. active, busy or anxious thinking, active concentration
  4. benzodiazepines
  • Delta (<4Hz)
  1. frontally in adults
  2. posteriorly in children
  3. high amplitude waves
  4. adults slow wave sleep
  • Theta (4-7Hz)
  1. Found in locations not related to task at hand
  2. drowsiness or arousal in older children and adults
  3. idling
  • Alpha (8-12Hz)
  1. posterior regions of head, both sides, higher in amplitude on dominant side
  2. Relaxed/reflecting with eyes closed

Hence beta -> alpha -> theta -> Delta = ANSWER (C)

Physiology of muscle & NMJ

  • New*

Isometric contraction

A. Force of contraction independent of the initial fibre length

B. Force of contractionis independent of initial load

C. Velocity of contraction is independent of load

D. Not associated with decreased fibre length? Z-Z length?


Maternal, foetal & neonatal physiology

Clinical measurement

  • new*

Laminar flow is directly proportional to

A. Length

B. Viscosity

C. Radius4

D. Density

E. Velocity

  • New*

Pulse oximeter underestimates saturation with

A. Carboxyhaemoglobinameia

B. Fluorescin dye

C. Hyperbilirubinaemia

D. Fetal Hb

E. Sickle cell Hb

  • A) Falsely elevates SpO2 (i.e. it reads high but is really lower - COHb of up to 48% can still read SpO2 of 91% - Dorsch and Drosch)
  • B) Fluorescin dye is NOT one of the dydes which interfere with SpO2 [1]
  • C) Hyperbilibubinaemia < 440 does NOT interfere with SpO2 (does interfere with co-oximetry)
  • D) No effect
  • E) Controversial - so say it does, some say it doesn't. Not sure if trick question
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