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Question 1
Correct
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A 15-year-old boy was brought to the emergency room with complaints of a headache, stiffness of the neck, and photophobia. Upon observation, the following were noted: HR 124, BP 86/43, RR 30, SaO 95%, temperature 39.5 deg C. A recently developed non-blanching rash on his legs was also observed.
What is most likely the causative agent of the case presented above?Your Answer: Neisseria meningitidis group B
Explanation:The meningococcus is solely a human pathogen, and up to 50% of the population may carry meningococci in the nasopharynx. Factors that lead to invasion and production of disease include complex inter-relationships of genetic predisposition, host status, environmental conditions, and virulence of the organism.
Meningococcal disease is the most common infectious cause of death in childhood in developed countries. It presents as septicaemia, meningitis, or a combination. Septicaemia is the more dangerous presentation, especially with septic shock; meningitis is more likely to lead to neurodevelopmental sequelae. Classic features of septicaemia are a non-blanching rash in a feverish, ill child.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 2
Incorrect
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A 71-year-old woman presents with complaints of fatigue and worsening muscle weakness, and blood tests done shows a potassium level of 2.4 mmol/L.
Which is NOT a recognised cause of hypokalaemia?
Your Answer: Bartter’s syndrome
Correct Answer: Type 4 renal tubular acidosis
Explanation:A plasma potassium less than 3.5 mmol/L defines hypokalaemia.
Excessive liquorice ingestion causes hypermineralocorticoidism and leads to hypokalaemia.
Gitelman’s syndrome causes metabolic alkalosis with hypokalaemia and hypomagnesaemia. It is an inherited defect of the distal convoluted tubules.
Bartter’s syndrome causes hypokalaemic alkalosis. It is a rare inherited defect in the ascending limb of the loop of Henle.
Type 1 and 2 renal tubular acidosis both cause hypokalaemia
Type 4 renal tubular acidosis causes hyperkalaemia.
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 3
Correct
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The blood test reports of a 56-year-old female are sent for your review. She seems acutely sick and has had multiple infections over the past few months. Her complete blood count report shows neutropenia.
Which one of the following options is true with regards to neutropenia?Your Answer: It can be caused by both radiotherapy and chemotherapy
Explanation:A total neutrophil count of less than 2 x 109/L is defined as neutropenia. It can be caused by the following:
1. viral infections
2. SLE
3. RA
4. hypersplenism
5. chemo- and radiotherapy
6. vitamin B12 and folate deficiency
7. drug reactions -
This question is part of the following fields:
- Haematology
- Pathology
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Question 4
Correct
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What is the most common application of Nitrates?
Your Answer: Angina
Explanation:In patients with exertional stable angina, nitrates improve exercise tolerance, time to onset of angina, and ST-segment depression during exercise testing. In combination with beta-blockers or calcium channel blockers, nitrates produce greater anti-anginal and anti-ischemic effects.
While they act as vasodilators, coronary vasodilators, and modest arteriolar dilators, the primary anti ischemic effect of nitrates is to decrease myocardial oxygen demand by producing systemic vasodilation more than coronary vasodilation. This systemic vasodilation reduces left ventricular systolic wall stress. -
This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 5
Correct
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A 21-year-old student presents to the minors area of your Emergency Department with a laceration on his external nose that occurred during sparring in a kickboxing class. The area is bleeding profusely and will require suturing. Pressure is being applied. The laceration extends through some of the nasal muscles.
Motor innervation of the nasal muscles of facial expression is provided by which of the following ? Select ONE answer only.Your Answer: Facial nerve
Explanation:The facial nerve (the labyrinthine segment) is the seventh cranial nerve, or simply CN VII. It emerges from the pons of the brainstem, controls the muscles of facial expression, and functions in the conveyance of taste sensations from the anterior two-thirds of the tongue.
Motor innervation of the nasal muscles of facial expression is provided by the facial nerve (CN VII). -
This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 6
Incorrect
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Regarding dynamic compression of the airways, which of the following statements is CORRECT:
Your Answer: It is brought about by reflex activation of sympathetic nerves.
Correct Answer: It occurs during forced expiration.
Explanation:Dynamic compression occurs because as the expiratory muscles contract during forced expiration, all the structures within the lungs, including the airways, are compressed by the positive intrapleural pressure. Consequently the smaller airways collapse before the alveoli empty completely and some air remains within the lungs (the residual volume). Physiologically this is important as a completely deflated lung with collapsed alveoli requires significantly more energy to inflate. Dynamic compression does not occur in normal expiration because the intrapleural pressure is negative throughout the whole cycle.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 7
Correct
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A 54-year-old woman has been visiting her GP with symptoms of tiredness, muscle weakness and headaches. She is known to be hypertensive and takes amlodipine to control this. Her blood results today show that her potassium level is low at 3.0 mmol/L, and her sodium level is slightly elevated at 146 mmol/L.
Which of the following is the SINGLE most appropriate INITIAL investigation?Your Answer: Plasma renin and aldosterone levels
Explanation:Primary hyperaldosteronism occurs when there are excessive levels of aldosterone independent of the renin-angiotensin axis. Secondary hyperaldosteronism occurs due to high renin levels.
The causes of primary hyperaldosteronism include:
Adrenal adenoma (Conn’s syndrome) – the most common cause of hyperaldosteronism (,80% of all cases). These are usually unilateral and solitary and are more common in women.
Adrenal hyperplasia – this accounts for ,15% of all cases. Usually, bilateral adrenal hyperplasia (BAH) but can be unilateral rarely. More common in men than women.
Adrenal cancer – a rare diagnosis but essential not to miss
Familial aldosteronism – a rare group of inherited conditions affecting the adrenal glands
The causes of secondary hyperaldosteronism include:
Drugs – diuretics
Obstructive renal artery disease – renal artery stenosis and atheroma
Renal vasoconstriction – occurs in accelerated hypertension
Oedematous disorders – heart failure, cirrhosis and nephrotic syndrome
Patients are often asymptomatic. When clinical features are present, the classically described presentation of hyperaldosteronism is with:
Hypertension
Hypokalaemia
Metabolic alkalosis
Sodium levels can be normal or slightly raised
Other, less common, clinical features include:
Lethargy
Headaches
Muscle weakness (from persistent hypokalaemia)
Polyuria and polydipsia
Intermittent paraesthesia
Tetany and paralysis (rare)
Often the earliest sign of hyperaldosteronism is from aberrant urea and electrolytes showing hypokalaemia and mild hypernatraemia. If the patient is taking diuretics, and the diagnosis is suspected, these should be repeated after the patient has taken off diuretics.
If the diagnosis is suspected, plasma renin and aldosterone levels should be checked. Low renin and high aldosterone levels (with a raised aldosterone: renin ratio) is suggestive of primary aldosteronism.
If the renin: aldosterone ratio is high, then the effect of posture on renin, aldosterone and cortisol can be investigated to provide further information about the underlying cause of primary hyperaldosteronism. Levels should be measured lying at 9 am and standing at noon:
If aldosterone and cortisol levels fall on standing, this is suggestive of an ACTH dependent cause, e.g. adrenal adenoma (Conn’s syndrome)
If aldosterone levels rise and cortisol levels fall on standing, this is suggestive of an angiotensin-II dependent cause, e.g. BAH
Other investigations that can help to distinguish between an adrenal adenoma and adrenal hyperplasia include:
CT scan
MRI scan
Selective adrenal venous sampling -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 8
Correct
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A patient presents to ED complaining of pins and needles over the lateral three and a half digits. You suspect carpal tunnel syndrome. Which of the following clinical features would you most expect to see on examination:
Your Answer: Inability to touch the pad of the little finger with the thumb
Explanation:Compression of the median nerve in the carpal tunnel will result in weakness and atrophy of the thenar muscles – resulting in weakness of opposition, abduction and flexion of the thumb at the metacarpophalangeal joint and anaesthesia or paraesthesia over the distribution of the palmar digital branch of the median nerve (skin over the palmar surface and fingertips of the lateral three and a half digits). The adductor pollicis muscle is innervated by the ulnar nerve, and abduction of the fingers is produced by the interossei, also innervated by the ulnar nerve. Flexion of the interphalangeal joint of the thumb is produced by the flexor pollicis longus, and flexion of the distal interphalangeal joint of the index finger is produced by the flexor digitorum profundus. Median nerve injury at the wrist will not affect the long flexors of the forearm as these are innervated by the anterior interosseous nerve which arises in the proximal forearm.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 9
Incorrect
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A migrant from Eastern Europe needs to have screening performed for tuberculosis (TB) because he is a high-risk patient.
Which statement concerning TB screening in the UK is true?
Your Answer: The Mantoux test involves the injection via a multi-pronged gun of 100,000 units/ml of tuberculin purified protein derivative into the skin
Correct Answer: Vaccination with the BCG can result in a false positive test
Explanation:Vaccination with the BCG can result in a false positive test.
The Mantoux test replaced the Heaf test as the TB screening test in the UK in 2005.
The ‘Sterneedle’ gun is used to inject 100,000 units/ml of tuberculin purified protein derivative into the skin for the Heaf testThe Mantoux test involves the injection of 5 Tuberculin units (0.1mL) intradermally and the result read 2-3 days later.
The interferon gamma release assay (IGRA) should NOT be used for neonates
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 10
Incorrect
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Regarding the cardiac cycle, which of the following statements is INCORRECT:
Your Answer: Diastole is usually twice the length of systole.
Correct Answer: The second heart sound occurs in late diastole caused by closure of the atrioventricular valves.
Explanation:Diastole is usually twice the length of systole at rest, but decreases with increased heart rate. During systole, contraction of the ventricles compresses the coronary arteries and suppresses blood flow. This is particularly evident in the left ventricle, where during systole the ventricular pressure is the same as or greater than that in the arteries and as a result more than 85% of left ventricular perfusion occurs during diastole. This becomes a problem if the heart rate is increased as the diastolic interval is shorter and can result in ischaemia. The second heart sound, caused by closure of the semilunar valves, marks the end of systole.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 11
Correct
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For which of the following infections is phenoxymethylpenicillin (penicillin V) primarily used?
Your Answer: Streptococcal tonsillitis
Explanation:Phenoxymethylpenicillin (penicillin V) is less active than benzylpenicillin but both have similar antibacterial spectrum. Because penicillin V is gastric-acid stable, it is suitable for oral administration, but should not be used for serious infections as absorption can be unpredictable and plasma concentrations can be variable.
Its uses are:
1. mainly for respiratory tract infections in children
2. for streptococcal tonsillitis
3. for continuing treatment after one or more injections of benzylpenicillin when clinical response has begun.
4. for prophylaxis against streptococcal infections following rheumatic fever and against pneumococcal infections following splenectomy or in sickle-cell disease.It should not be used for meningococcal or gonococcal infections.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 12
Correct
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Question 13
Incorrect
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Which extraocular muscle is entrapped in a patient with a blowout fracture?
Your Answer: Inferior oblique
Correct Answer: Inferior rectus
Explanation:A blowout fracture is an isolated fracture of the orbital walls without compromise of the orbital rims. The common mechanisms are falls, high-velocity ball-related sports, traffic accidents, and interpersonal violence.
The frontal, ethmoidal, sphenoid, zygomatic, and lacrimal bones form the bony structures of the orbit. Medially, the maxillary and the lacrimal bone form the lacrimal fossa. Together with the lamina papyracea of the ethmoid bone, they form the medial wall. The sphenoid bone forms the posterior wall and houses the orbital canal. Lateral to the orbital canal lies the superior orbital fissure housing cranial nerves III, IV, V, and VI. The zygomatic bone forms the lateral wall. Superior and inferior borders are the frontal and maxillary bones. Located around the globe of the eye and attached to it are 6 extraocular muscles; the 4 rectus muscles and the superior and inferior oblique muscles. The fat and connective tissue around the globe help to reduce the pressure exerted by the extraocular muscles.
The goal of treatment is to restore aesthetics and physiological function. The problem with orbital blowout fractures is that the volume of the orbit can be increased, resulting in enophthalmos and hypoglobus. In addition, the orbital tissue and inferior rectus muscle can become trapped by the bony fragments leading to diplopia, limitation of gaze, and tethering. Finally, the orbital injury can lead to retinal oedema, hyphema, and significant loss of vision.
While some cases may be managed with conservative care, others may require some type of surgical intervention.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 14
Incorrect
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The cutaneous circulation is responsible for the skin's blood supply. Because the skin is not a highly metabolically active tissue with low energy requirements, its blood supply differs from that of other tissues. Instead of capillaries, some of the circulating blood volume in the skin passes through arteriovenous anastomoses (AVAs).
Which of the following statements regarding arteriovenous anastomoses is correct?
Your Answer: AVAs are short vessels with little to no smooth muscle in their walls
Correct Answer: AVAs are innervated by sympathetic fibres originating from the hypothalamus
Explanation:Short vessels called arteriovenous anastomoses (AVAs) link tiny arteries and veins. They have a large lumen diameter. The strong and muscular walls allow AVAs to completely clog the vascular lumen, preventing blood flow from artery to vein (acting like a sphincter). When the AVAs open, they create a low-resistance connection between arteries and veins, allowing blood to flow into the limbs’ superficial venous plexuses. There is no diffusion of solutes or fluid into the interstitium due to their strong muscle walls.
AVAs are densely innervated by adrenergic fibres from the hypothalamic temperature-regulation centre. High sympathetic output occurs at normal core temperatures, inducing vasoconstriction of the AVAs and blood flow through the capillary networks and deep plexuses. When the temperature rises, sympathetic output decreases, producing AVA vasodilation and blood shunting from the artery to the superficial venous plexus. Heat is lost to the environment as hot blood rushes near to the skin’s surface.
AVAs are a specialized anatomical adaptation that can only be found in large quantities in the fingers, palms, soles, lips, and pinna of the ear. -
This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
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Question 15
Correct
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A 33 year old lady with a known nut allergy was having dinner at a Thai restaurant. She suddenly complained of lip and tongue swelling and difficulty breathing and is brought to ED by ambulance with suspected anaphylaxis. She received intramuscular adrenaline in the ambulance.
The most appropriate doses of the second line treatments for anaphylaxis are which of the following?Your Answer: 10 mg chlorphenamine and 200 mg hydrocortisone
Explanation:Second line drugs to reduce the severity and duration of anaphylactic symptoms are intravenous or intramuscular chlorpheniramine and hydrocortisone. The recommended dose is 10 mg chlorpheniramine and 200 mg hydrocortisone in adults.
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 16
Correct
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Platelet alpha granules release which of the following?
Your Answer: Von Willebrand factor (VWF)
Explanation:There are three types of storage granules contained in platelets. These are dense granules which contain the following:
-ATP
-ADP
-serotonin and calcium alpha granules containing clotting factors
-von Willebrand factor (VWF)
-platelet-derived growth factor (PDGF)
– other proteins lysosomes containing hydrolytic enzymes. -
This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 17
Correct
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A 28 year old man presents with abdominal pain and constipation, and bloods show hypocalcaemia. Which of the following hormones is increased as a result of hypocalcaemia?
Your Answer: Parathyroid hormone
Explanation:Parathyroid hormone (PTH), also called parathormone or parathyrin, is a peptide hormone that is secreted by the parathyroid glands, which lie immediately behind the thyroid gland. In particular, this hormone is made by chief cells. It regulates the serum calcium concentration through its effects on bone, kidney, and intestine. This hormone is primarily released in response to decreasing plasma Ca2+ concentration and it serves to increase plasma calcium levels and decrease plasma phosphate levels.
PTH activates Ca2+entry channels in the apical membrane and the Ca2+ATPase pump in the basolateral membrane and as a result, increases calcium reabsorption in the distal tubule of the nephron. It inhibits reabsorption of phosphate and this increases its excretion by in the proximal tubule of the nephron. -
This question is part of the following fields:
- Endocrine
- Physiology
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Question 18
Incorrect
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Regarding alteplase, which of the following statements is INCORRECT:
Your Answer: Alteplase is a recombinant tissue-type plasminogen activator.
Correct Answer: Alteplase is commonly associated with hypotensive effects.
Explanation:Alteplase is a recombinant tissue-type plasminogen activator (tPA), a naturally occurring fibrin-specific enzyme that has selectivity for activation of fibrin-bound plasminogen. It has a short half-life of 3 – 4 minutes and must be given by continuous intravenous infusion but is not associated with antigenic or hypotensive effects, and can be used in patients when recent streptococcal infections or recent use of streptokinase contraindicates the use of streptokinase.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 19
Correct
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A 32 year old man is brought to ED having been thrown off his motorbike. Following initial resuscitation and ruling out life-threatening injuries, you establish the patient has weakness of hip flexion. Which of the following nerves has most likely been injured:
Your Answer: Femoral nerve
Explanation:Flexion of the hip is produced by the iliacus, the psoas major, the sartorius, rectus femoris and the pectineus muscles. The femoral nerve innervates the iliacus, pectineus, sartorius and quadriceps femoris muscles, and supplies skin on the anterior thigh, anteromedial knee and medial leg.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 20
Incorrect
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Which of the following is NOT a typical clinical feature of beta-thalassaemia major:
Your Answer: Increased susceptibility to infection
Correct Answer: Increased bleeding tendency
Explanation:Features include:
– severe anaemia (becoming apparent at 3 – 6 months when the switch from gamma-chain to beta-chain production takes place)
– failure to thrive
– hepatosplenomegaly (due to excessive red cell destruction, extramedullary haemopoiesis and later due to transfusion related iron overload)
– expansion of bones (due to marrow hyperplasia, resulting in bossing of the skull and cortical thinning with tendency to fracture)
– increased susceptibility to infections (due to anaemia, iron overload, transfusion and splenectomy)
– osteoporosis
– hyperbilirubinaemia and gallstones
– hyperuricaemia and gout
– other features of haemolytic anaemia
– liver damage and other features of iron overload -
This question is part of the following fields:
- Haematology
- Pathology
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Question 21
Correct
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Regarding ACE inhibitors, which of the following statements is CORRECT:
Your Answer: Angiotensin-II receptor blockers are a useful alternative in patients who cannot tolerate ACE-inhibitors due a persistent cough.
Explanation:ACE inhibitors should be used with caution in patients of Afro-Caribbean descent who may respond less well; calcium channel blockers are first line for hypertension in these patients. ACE inhibitors have a role in the management of diabetic nephropathy. ACE inhibitors are contraindicated in pregnant women. ACE inhibitors inhibit the breakdown of bradykinin; this is the cause of the persistent dry cough. Blocking ACE also diminishes the breakdown of the potent vasodilator bradykinin which is the cause of the persistent dry cough. Angiotensin-II receptor blockers do not have this effect, therefore they are useful alternative for patients who have to discontinue an ACE inhibitor because of persistent cough.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 22
Correct
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Diagnosis of HIV is predominantly made through which of the following:
Your Answer: Antibody detection
Explanation:Diagnosis of HIV is predominantly made through detection of HIV antibody and p24 antigen. Viral load (viral PCR) and CD4 count are used to monitor progression of disease.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 23
Correct
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A 32 year old woman presents with episodes of flushing, headaches and palpitations. On examination her blood pressure is significantly elevated. Which of the following is the most likely diagnosis:
Your Answer: Pheochromocytoma
Explanation:Phaeochromocytomas are catecholamine-secreting tumours which occur in about 0.1% of patients with hypertension. In about 90% of cases they arise from the adrenal medulla. The remaining 10%, which arise from extra-adrenal chromaffin tissue, are termed paragangliomas. Common presenting symptoms include one or more of headache, sweating, pallor and palpitations. Less commonly, patients describe anxiety, panic attacks and pyrexia. Hypertension, whether sustained or episodic, is present in at least 90% of patients. Left untreated phaeochromocytoma can occasionally lead to hypertensive crisis, encephalopathy, hyperglycaemia, pulmonary oedema, cardiac arrhythmias, or even death.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 24
Incorrect
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Nitric oxide release from endothelium is stimulated by all of the following EXCEPT for:
Your Answer: Substance P
Correct Answer: Noradrenaline
Explanation:Nitric oxide (NO) production by the endothelium is increased by factors that elevate intracellular Ca2+, including local mediators such as bradykinin, histamine and serotonin, and some neurotransmitters (e.g. substance P). Increased flow (shear stress) also stimulates NO production and additionally activates prostacyclin synthesis. The basal production of NO continuously modulates vascular resistance; increased production of nitric oxide acts to cause vasodilation. Nitric oxide also inhibits platelet activation and thrombosis.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 25
Incorrect
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Fenestrated capillaries are typically found where in the body:
Your Answer: Reticuloendothelial system
Correct Answer: Renal glomeruli
Explanation:Fenestrated capillaries, found in renal glomeruli, endocrine glands and intestinal villi, are more permeable than continuous capillaries with less tight junctions, and the endothelial cells are also punctured by pores which allow large amounts of fluids or metabolites to pass.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 26
Correct
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A 13-year-old male presents to the Emergency Department with a heavy nosebleed. His medical record shows that he was diagnosed with Haemophilia B as a child.
What is the mode of inheritance of this disease?Your Answer: X-linked recessive
Explanation:Deficiency of Factor IX causes Haemophilia B, and like the other Haemophilia’s, it has an X-linked recessive pattern of inheritance, affecting males born to carrier mothers.
Haemophilia B is the second commonest form of haemophilia and is rarer than haemophilia A. Haemophilia B is similar to haemophilia A but is less severe. You can distinguish the two disorders by specific coagulation factor assays.
The incidence of Haemophilia B is one-fifth of that of haemophilia A.
In laboratory findings, you get prolonged APTT, normal PT and low factor IX for Haemophilia B.
There is also a variation called Leyden, in which factor IX levels are below 1% until puberty, when they rise, potentially reaching as high as 40-60% of normal. This is thought to be due to the effects of testosterone at puberty.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 27
Correct
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Which of the following is NOT mainly characterised by intravascular haemolysis:
Your Answer: Beta-Thalassaemia
Explanation:Causes of intravascular haemolysis:
Haemolytic transfusion reactions
G6PD deficiency
Red cell fragmentation syndromes
Some severe autoimmune haemolytic anaemias
Some drug-and infection-induced haemolytic anaemias
Paroxysmal nocturnal haemoglobinuria -
This question is part of the following fields:
- Haematology
- Pathology
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Question 28
Correct
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A 43-year old male is taken to the Emergency Room for a lacerated wound on the abdomen, situated above the umbilicus. A short segment of the small bowel has herniated through the wound.
Which of these anatomic structures is the deepest structure injured in the case above?Your Answer: Transversalis fascia
Explanation:The following structures are the layers of the anterior abdominal wall from the most superficial to the deepest layer:
Skin
Fatty layer of the superficial fascia (Camper’s fascia)
Membranous layer of the superficial fascia (Scarpa’s fascia)
Aponeurosis of the external and internal oblique muscles
Rectus abdominis muscle
Aponeurosis of the internal oblique and transversus abdominis
Fascia transversalis
Extraperitoneal fat
Parietal peritoneum -
This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 29
Correct
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Regarding codeine, which of the following statements is INCORRECT:
Your Answer: There is a reduced risk of toxicity in patients who are ultra-rapid metabolisers of codeine.
Explanation:Codeine phosphate is a weak opioid and can be used for the relief of mild to moderate pain where other painkillers such as paracetamol or ibuprofen have proved ineffective.Codeine is metabolised to morphine which is responsible for its therapeutic effects. Codeine 240 mg is approximately equivalent to 30 mg of morphine. The capacity to metabolise codeine can vary considerably between individuals; there is a marked increase in morphine toxicity in people who are ultra rapid metabolisers, and reduced therapeutic effect in poor codeine metabolisers. Codeine is contraindicated in patients of any age who are known to be ultra-rapid metabolisers of codeine (CYP2D6 ultra-rapid metabolisers).Codeine is also contraindicated in children under 12, and in children of any age who undergo the removal of tonsils or adenoids for the treatment of obstructive sleep apnoea due to reports of morphine toxicity.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 30
Correct
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About case-control studies, one of the following is true.
Your Answer: They are suitable to be used in the study of rare diseases
Explanation:Case-control studies are suitable when investigating a rare disease or in cases where little is known about the disease and the proposed aetiological factor, as a preliminary study. They have the ability to look at multiple risk-factors (exposures) but can only look at a single outcome.
In a case-control study, two groups of patients, one with the disease and one without, are compared on the basis of a proposed causative factor that occurred in the past. They are therefore a retrospective study and useful in hypothesis generation.
Cohort studies are better at identifying rare exposures. One group with an exposure is compared to a control group without that exposure.
Case-control studies are usually less expensive to run and also shorter in duration compared with prospective cohort studies.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 31
Incorrect
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Which of the following statements about lithium treatment is FALSE:
Your Answer: Patients taking lithium should carry a lithium treatment card.
Correct Answer: Concomitant treatment with NSAIDs decreases serum-lithium concentration.
Explanation:Lithium levels are raised by NSAIDs because renal clearance is reduced. Lithium is a small ion (74 Daltons) with no protein or tissue binding and is therefore amenable to haemodialysis. Lithium is freely distributed throughout total body water with a volume of distribution between 0.6 to 0.9 L/kg, although the volume may be smaller in the elderly, who have less lean body mass and less total body water. Steady-state serum levels are typically reached within five days at the usual oral dose of 1200 to 1800 mg/day. The half-life for lithium is approximately 18 hours in adults and 36 hours in the elderly.
Lithium is excreted almost entirely by the kidneys and is handled in a manner similar to sodium. Lithium is freely filtered but over 60 percent is then reabsorbed by the proximal tubules. -
This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 32
Correct
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Regarding cardiac excitation-contraction coupling, which of the following statements is CORRECT:
Your Answer: The Treppe effect refers to an increase in contractility secondary to an increase in heart rate.
Explanation:Although Ca2+entry during the action potential (AP) is essential for contraction, it only accounts for about 25% of the rise in intracellular Ca2+. The rest is released from Ca2+stores in the sarcoplasmic reticulum (SR). In relaxation, about 80% of Ca2+is rapidly pumped back into the SR (sequestered) by Ca2+ATPase pumps. The Ca2+that entered the cell during the AP is transported out of the cell primarily by the Na+/Ca2+exchanger in the membrane. When more action potentials occur per unit time, more Ca2+enters the cell during the AP plateau, more Ca2+is stored in the SR, more Ca2+is released from the SR and thus more Ca2+is left inside the cell and greater tension is produced during contraction. Increased heart rate increases the force of contraction in a stepwise fashion as intracellular [Ca2+] increases cumulatively over several beats; this is the Treppe effect. Cardiac glycosides such as digoxin have a positive inotropic effect.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 33
Correct
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Regarding airway resistance, which of the following statements is INCORRECT:
Your Answer: In the lower respiratory tract, airway resistance is mostly determined by the smallest bronchioles.
Explanation:Airway resistance is primarily determined by the airway radius according to Poiseuille’s law, and whether the flow is laminar or turbulent. The major site of airway resistance is the medium-sized bronchi. The smallest airways would seem to offer the highest resistance, but they do not because of their branching parallel arrangement.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 34
Correct
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You're called to a cardiac arrest in your Emergency Department resuscitation area. The rhythm strip is shown in the diagram below. Defibrillation has already been attempted three times on the patient. You intended to administer amiodarone, but your department has informed you that it is not available. In these circumstances, if amiodarone is not available, which of the following drugs is recommended by the ALS guidelines?
Your Answer: Lidocaine
Explanation:If amiodarone is unavailable in VF/pVT arrests, lidocaine at a dose of 1 mg/kg can be used instead, according to the latest ALS guidelines. If amiodarone has already been given, no lidocaine should be given.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 35
Correct
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The only statement that is correct regarding diffusion is which of the following?
Your Answer: The permeability of a membrane is related to the membrane thickness and composition.
Explanation:Passive diffusion is a process that describes the movement down a concentration gradient. This process accounts for movement across small distances like within the cytosol or across membranes. Factors that affect the diffusion of a substance across a membrane are the permeability (p) of the membrane, a difference in concentration across the membrane and the membrane area over which diffusion occurs. The membrane thickness and composition, and the diffusion coefficient of the substance also affects the permeability. Fick’s law describes the rate of diffusion of a substance within a solution, which can be modified to describe the rate of diffusion across a membrane.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 36
Correct
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Which of the following statements is correct with regards to Hodgkin's lymphoma?
Your Answer: Most patients present with painless asymmetrical lymphadenopathy, with cervical nodes involved most commonly.
Explanation:Lymphoma is a cancer of the lymphatic system, which is part of the body’s germ-fighting network. They are a group of diseases that are caused by malignant lymphocytes. These malignant cells accumulate in lymph nodes and other lymphoid tissue, giving rise to the characteristic clinical feature of lymphadenopathy.
They can be subdivided into Hodgkin lymphoma (HL) which are characterised by the presence of Reed-Sternberg cells, and non-Hodgkin lymphoma (NHL).
Characteristics of HL include:
1. can present at any age but is rare in children and has a peak incidence in young adults,
2. almost 2:1 male predominance.
3. presents with painless, asymmetrical, firm and discrete enlargement of superficial lymph nodes.
4. cervical node involvement in 60-70% of cases,
5. axillary node involvement in 10-15%
6. inguinal node involvement in 6-12%.
7. modest splenomegaly during the course of the disease in 50% of patients
8. may occasionally have liver enlargement
9. bone marrow failure involvement is unusual in early disease.
Approximately 85% of patients are cured, but the prognosis depends on age, stage and histology.
Two well‐known but rare symptoms in HL are alcohol‐induced pain and pruritus. -
This question is part of the following fields:
- Haematology
- Pathology
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Question 37
Incorrect
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One of these statements about cohort studies is true:
Your Answer: They are the best way to determine the prevalence of a disease
Correct Answer: They are longitudinal in nature
Explanation:A cohort study is a longitudinal, observational study. It follows a group of patients (the cohort) forward in time and monitors the effects of the aetiological factor under study upon them.
Cohort studies are usually of longer duration and are more expensive than case-control studies. They, however, provide more useful and reliable information.
Cohort studies follow a cohort of patients who don’t have a disease and evaluate the absolute and relative risk of contracting the disease after exposure to the aetiological agent.
Cross-sectional studies are the best way to determine the prevalence of a disease. while Cohort studies are better at determining the incidence of a disease.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 38
Incorrect
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Identify the type of graph described below:
A graph that consists of a vertical bar graph in which values are plotted in decreasing order of relative frequency from left to right. The independent variables on the chart are shown on the horizontal axis and the dependent variables are portrayed as the heights of bars.Your Answer: Histogram
Correct Answer: Pareto diagram
Explanation:A pareto diagram, or pareto chart, consists of a vertical bar graph in which values are plotted in decreasing order of relative frequency from left to right. The independent variables on the chart are shown on the horizontal axis and the dependent variables are portrayed as the heights of bars.
A point-to-point graph, which shows the cumulative relative frequency, may be superimposed on the bar.
Because the values of the statistical variables are placed in order of relative frequency, the graph clearly reveals which factors have the greatest impact and where attention is likely to yield the greatest benefit. It is extremely useful for analysing what problems need attention first, because the taller bars on the chart clearly illustrate which variable have the greatest cumulative effect on a given system.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 39
Incorrect
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Regarding atracurium, which of the following statements is CORRECT:
Your Answer: Atracurium has a potent analgesic effect.
Correct Answer: Effects such as flushing, tachycardia and hypotension can occur due to significant histamine release.
Explanation:Cardiovascular effects such as flushing, tachycardia, hypotension and bronchospasm are associated with significant histamine release; histamine release can be minimised by administering slowly or in divided doses over at least 1 minute. Atracurium undergoes non-enzymatic metabolism which is independent of liver and kidney function, thus allowing its use in patients with hepatic or renal impairment. Atracurium has no sedative or analgesic effects. All non-depolarising drugs should be used with care in patients suspected to be suffering with myasthenia gravis or myasthenic syndrome, as patients with these conditions are extremely sensitive to their effects and may require a reduction in dose.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 40
Correct
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Which of the following is where the rectovesical fascia is located:
Your Answer: Between the fundus of the bladder and the ampulla of the rectum
Explanation:In a triangular area between the vasa deferentia, the bladder and rectum are separated only by rectovesical fascia, commonly known as Denonvillier’s fascia.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 41
Correct
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Question 42
Correct
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A 70-year-old patient diagnosed with Cushing's syndrome, has a history of weight gain, hypertension, and easy bruising.
Which of the following statements about Cushing's syndrome is NOT true?Your Answer: Menorrhagia is a common feature
Explanation:Cushing’s syndrome is a group of symptoms and signs brought on by long-term exposure to high amounts of endogenous or exogenous glucocorticoids.
Iatrogenic corticosteroid injection is the most prevalent cause of Cushing’s syndrome.
Cortisol levels fluctuate throughout the day, with the greatest levels occurring around 0900 hours and the lowest occurring at 2400 hrs during sleep. The diurnal swing of cortisol levels is lost in Cushing’s syndrome, and levels are greater throughout the 24-hour period. In the morning, levels may be normal, but they may be high at night-time, when they are generally repressed.Insulin resistance causes hyperglycaemia, which is a frequent symptom. Insulin resistance can produce acanthosis nigricans in the axilla and around the neck, as well as other skin abnormalities.
In contrast to menorrhagia, elevated testosterone levels are more likely to produce amenorrhoea or oligomenorrhoea. Infertility in women of reproductive age can also be caused by high androgen levels.
A dexamethasone suppression test or a 24-hour urine free cortisol collection can both be used to establish the existence of Cushing’s syndrome.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 43
Correct
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Regarding acute lymphoblastic leukaemia (ALL), which of the following statements is CORRECT:
Your Answer: ALL is the most common malignancy of childhood.
Explanation:Acute lymphoblastic leukaemia (ALL) is caused by an accumulation of lymphoblasts in the bone marrow and is the most common malignancy of childhood. The incidence of ALL is highest at 3 – 7 years, with 75% of cases occurring before the age of 6. 85% of cases are of B-cell lineage. Haematological investigations reveal a normochromic normocytic anaemia with thrombocytopenia in most cases. The total white cell count may be decreased, normal or increased. The blood film typically shows a variable number of blast cells. The bone marrow is hypercellular with >20% blast cells.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 44
Correct
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The juxtacapillary receptors, or J receptors, are sensory cells that play an important role in the control of respiration.
At which of the following anatomical sites are the J receptors located? Select ONE answer only.Your Answer: The alveolar walls
Explanation:Juxtacapillary receptors (J receptors) are sensory cells that are located within the alveolar walls in juxtaposition to the pulmonary capillaries of the lung.
The J receptors are innervated by the vagus nerve and are activated by physical engorgement of the pulmonary capillaries or increased pulmonary interstitial volume, for example, in the presence of pulmonary oedema, pulmonary embolus, pneumonia and barotraumas. They may also be stimulated by hyperinflation of the lung.
Stimulation of the J receptors causes a reflex increase in breathing rate and is also thought to be involved in the sensation of dyspnoea. The reflex response that is produced is apnoea, followed by rapid breathing, bradycardia, and hypotension. -
This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 45
Correct
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Amoxicillin is used first line for all of the following infections EXCEPT for:
Your Answer: Cellulitis
Explanation:Amoxicillin is used first line for low to moderate severity community acquired pneumonia, exacerbations of chronic bronchitis, for acute otitis media, for acute sinusitis, for oral infections/dental abscess, for Listeria meningitis (in combination with another antibiotic), for infective endocarditis (in combination with another antibiotic) and for H. Pylori eradication (in combination with metronidazole/clarithromycin and a PPI). Flucloxacillin is used first line for acute cellulitis.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 46
Correct
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Regarding non-Hodgkin lymphoma (NHL), which of the following statements is CORRECT:
Your Answer: There is a much greater predilection to disseminate to extranodal sites than in Hodgkin lymphoma.
Explanation:Non-Hodgkin’s lymphoma (NHL) refers to a group of lymphoproliferative malignancies (about 85% of B-cell and 15% of T or NK (natural killer) cell origin) with different behavioural patterns and treatment responses. This group of malignancies encompasses all types of lymphoma without Reed-Sternberg cells being present. The Reed-Sternberg cell is classically seen in Hodgkin’s lymphoma.
NHL is five times as common as Hodgkin’s lymphoma. The peak incidence of NHL is in the 50-70 years age group, it affects men and women equally, but affects the Caucasian population more commonly than black and Asian ethnic groups.
The following are recognised risk factors for NHL:
Chromosomal translocations and molecular rearrangements
Epstein-Barr virus infection
Human T-cell leukaemia virus type-1 (HTLV-1)
Hepatitis C
Congenital and acquired immunodeficiency states
Autoimmune disorders, e.g. Sjogren’s syndrome and Hashimoto’s thyroiditis
The most common clinical features at presentation are:
Lymphadenopathy (typically asymmetrical and painless)
Weight loss
Fatigue
Night sweats
Hepatosplenomegaly
For clinical purposes, NHL is divided into three groups: indolent, high-grade, and lymphoblastic.
Indolent (low-grade) NHL:
The cells are relatively mature
Disease follows an indolent course without treatment
Often acceptable to follow a ‘watch and wait’ strategy
Local radiotherapy often effective
Relatively good prognosis with median survival of 10 years
High-grade NHL:
Cells are immature
Disease progresses rapidly without treatment
Significant number of patients can be cured with intensive combination chemotherapy regimens
Approximately 40% cure rate
Lymphoblastic NHL:
Cells are very immature and have a propensity to involve the CNS
Treatment and progression are similar to that of acute lymphoblastic leukaemia (ALL) -
This question is part of the following fields:
- Haematology
- Pathology
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Question 47
Correct
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A 43 year old lady suffering with idiopathic thrombocytopenic purpura has a splenectomy. She is advised to get the Pneumococcal vaccine booster every 5 - 10 years as Streptococcus pneumoniae has which of the following properties that make her prone to infection to this organism?
Your Answer: It is encapsulated
Explanation:There is a lifelong susceptibility to increased risk of infection from a variety of organisms in patients with hyposplenism, especially in children under 5 years and those with sickle cell anaemia. Patients are most susceptible is to the encapsulated bacteria Streptococcus pneumoniae, Haemophilus influenzae type B and Neisseria meningitidis. Streptococcus pneumoniae is particular concerning as it can cause rapid and fulminant disease, which can be fatal. Malaria and animal bites that become infected also tend to be more severe.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 48
Correct
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A 58-year-old woman presents with symptoms of increase in weight, proximal muscular weakening and withering, easy bruising, and acne. You notice that she has a full, plethoric aspect to her face, as well as significant supraclavicular fat pads, when you examine her. She has previously been diagnosed with Cushing's syndrome.
Cushing's syndrome is most commonly caused by which of the following?Your Answer: Iatrogenic administration of corticosteroids
Explanation:Cushing’s syndrome is a group of symptoms and signs brought on by long-term exposure to high amounts of endogenous or exogenous glucocorticoids. Cushing’s syndrome affects about 10-15 persons per million, and it is more common in those who have had a history of obesity, hypertension, or diabetes.
Iatrogenic corticosteroid injection is the most prevalent cause of Cushing’s syndrome. Cushing’s illness is the second most prevalent cause of Cushing’s syndrome. Cushing’s disease is distinct from Cushing’s syndrome in that it refers to a single cause of the illness, a pituitary adenoma that secretes high quantities of ACTH, which raises cortisol levels.
Cushing’s syndrome has several endogenous sources, including:
Cushing’s disease is caused by a pituitary adenoma.
Adrenal adenoma Ectopic corticotropin syndrome, e.g. small cell cancer of the lung
Adrenal carcinoma is a cancer of the adrenal gland.
Hyperplasia of the adrenal glands -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 49
Correct
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A dermatological examination of a patient who has presented with a lump shows a collection of boils clustered together.
Which one of these best describes the lump you have found on examination?Your Answer: Carbuncle
Explanation:A furuncle, or boil, is a pyogenic infection of the hair follicle commonly caused by infection with Staphylococcus aureus.
A carbuncle is a collection of individual boils clustered together.
A bulla is a visible collection of clear fluid measuring greater than 0.5 cm in diameter.
A vesicle is a visible collection of clear fluid measuring less than 0.5 cm in diameter.
A pustule is a small visible skin elevation containing an accumulation of pus.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 50
Correct
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What is the mechanism of action of captopril:
Your Answer: Angiotensin-converting enzyme inhibitor
Explanation:Captopril is an angiotensin-converting enzyme (ACE) inhibitor, which inhibits the conversion of angiotensin I to angiotensin II.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 51
Correct
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A 39-year-old man with a long history of depression presents after intentionally overdoing his heart medication. Verapamil immediate-release 240 mg is the tablet he takes for this condition, he says. He took the pills about 30 minutes ago, but his wife discovered him right away and rushed him to the emergency room.
Which of the following is a verapamil toxicity?Your Answer: Negative inotropy
Explanation:Overdosing on calcium-channel blockers should always be taken seriously and regarded as potentially fatal. Verapamil and diltiazem are the two most lethal calcium-channel blockers in overdose. These work by binding the alpha-1 subunit of L-type calcium channels, preventing calcium from entering the cell. In cardiac myocytes, vascular smooth muscle cells, and islet beta-cells, these channels play an important role.
The following summarises the toxicity of calcium-channel blockers:
Cardiac effects
Vascular smooth muscle tone affects
Metabolic effects
Excessive negative inotropy: myocardial depression
Negative chronotropy: sinus bradycardia
Negative dromotropy: atrioventricular node blockade
Decreased afterload
Systemic hypotension
Coronary vasodilation
Hypoinsulinaemia
Calcium channel blocker-induced insulin resistance -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 52
Correct
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In the foetus at 4 months gestation, where does haematopoiesis mainly occur?
Your Answer: Liver and spleen
Explanation:The first place that haematopoiesis occurs in the foetus is in the yolk sac. Later on, it occurs in the liver and spleen, which are the major hematopoietic organs from about 6 weeks until 6 – 7 months gestation. At this point, the bone marrow becomes the most important site. Haemopoiesis is restricted to the bone marrow in normal childhood and adult life.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 53
Correct
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A 16-year old boy is brought to the emergency room after suffering a traffic accident. Upon examination, there is noted ipsilateral loss of proprioception and vibration, ipsilateral motor loss, and contralateral loss of pain and temperature sensation. A spinal cord injury is given as a diagnosis.
Which of the following is the most probable cause of this manifestation?Your Answer: Brown-Séquard syndrome
Explanation:Brown-Sequard Hemicord Syndrome consists of ipsilateral weakness (corticospinal tract) and loss of joint position and vibratory sense (posterior column), with contralateral loss of pain and temperature sense (spinothalamic tract) one or two levels below the lesion. Segmental signs, such as radicular pain, muscle atrophy, or loss of a deep tendon reflex, are unilateral. Partial forms are more common than the fully developed syndrome.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 54
Correct
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Mannitol is primarily indicated for which of the following:
Your Answer: Cerebral oedema
Explanation:Mannitol is an osmotic diuretic that can be used to treat cerebral oedema and raised intraocular pressure. Mannitol is a low molecular weight compound and is, therefore, freely filtered at the glomerulus and is not reabsorbed. It, therefore, increases the osmolality of the glomerular filtrate and tubular fluid, increasing urinary volume by an osmotic effect. It also does not cross the blood-brain-barrier (BBB).
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 55
Correct
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In adults, there are normally how many teeth:
Your Answer: 32
Explanation:In adults, there are 32 teeth, 16 in the upper jaw and 16 in the lower jaw. On each side in both upper and lower arches, there are two incisors, one canine, two premolars and three molar teeth.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 56
Incorrect
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In the extrinsic pathway of the coagulation cascade, the tenase complex is:
Your Answer: Factor IXa-VIIIa complex
Correct Answer: Factor VIIa-tissue factor complex
Explanation:The extrinsic pathway for initiating the formation of prothrombin activator begins with a traumatized vascular wall or traumatized extravascular tissues that come in contact with the blood. Exposed and activated by vascular injury, with plasma factor VII. The extrinsic tenase complex, factor VIIa-tissue factor complex, activates factor X to factor Xa.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 57
Correct
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You've been summoned to your Emergency Department resuscitation area to see a patient. You consider giving him an atropine shot because he is severely bradycardic.
Which of the following statements about the use of atropine is correct?Your Answer: It blocks the effects of the vagus nerve on both the SA and AV nodes
Explanation:At muscarinic receptors, atropine blocks the action of the parasympathetic neurotransmitter acetylcholine. As a result, it inhibits the vagus nerve’s effects on both the SA and AV nodes, increasing sinus automaticity and facilitating AV node conduction.
At muscarinic receptors, atropine blocks the action of the parasympathetic neurotransmitter acetylcholine. As a result, it inhibits the vagus nerve’s effects on both the SA and AV nodes, increasing sinus automaticity and facilitating AV node conduction.
The most common cause of asystole during cardiac arrest is primary myocardial pathology, not excessive vagal tone, and there is no evidence that atropine is helpful in the treatment of asystole or PEA. As a result, it is no longer included in the ALS algorithm’s non-shockable section. Atropine is most commonly used in the peri-arrest period. It is used to treat bradycardia (sinus, atrial, or nodal) or AV block when the patient’s haemodynamic condition is compromised by the bradycardia.
If any of the following adverse features are present, the ALS bradycardia algorithm recommends a dose of 500 mcg IV:
Shock
Syncope
Myocardial ischaemia
Heart failureAtropine is also used for the following purposes:
Topically as a cycloplegic and mydriatic to the eyes
To cut down on secretions (e.g. in anaesthesia)
Organophosphate poisoning is treated with
Atropine’s side effects are dose-dependent and include:
Mouth is parched
Vomiting and nausea
Vision is hazy
Retention of urine
Tachyarrhythmias
It can also cause severe confusion and hallucinations in patients, especially the elderly. -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 58
Correct
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Which of the following is an action of glucagon:
Your Answer: Stimulates glycogenolysis
Explanation:Glucagon is a peptide hormone that is produced and secreted by alpha cells of the islets of Langerhans, which are located in the endocrine portion of the pancreas. The main physiological role of glucagon is to stimulate hepatic glucose output, thereby leading to increases in glycaemia. It provides the major counter-regulatory mechanism to insulin in maintaining glucose homeostasis.
Hypoglycaemia is the principal stimulus for the secretion of glucagon but may also be used as an antidote in beta-blocker overdose and in anaphylaxis in patients on beta-blockers that fail to respond to adrenaline.
Glucagon then causes:
Glycogenolysis
Gluconeogenesis
Lipolysis in adipose tissue
The secretion of glucagon is also stimulated by:
Adrenaline
Cholecystokinin
Arginine
Alanine
Acetylcholine
The secretion of glucagon is inhibited by:
Insulin
Somatostatin
Increased free fatty acids
Increased urea productionGlycolysis is the metabolic pathway that converts glucose into pyruvate. The free energy released by this process is used to form ATP and NADH. Glycolysis is inhibited by glucagon, and glycolysis and gluconeogenesis are reciprocally regulated so that when one cell pathway is activated, the other is inactive and vice versa.
Glucagon has a minor effect of enhancing lipolysis in adipose tissue. Lipolysis is the breakdown of lipids and involves the hydrolysis of triglycerides into glycerol and free fatty acids. It makes fatty acids available for oxidation.
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This question is part of the following fields:
- Endocrine
- Pharmacology
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Question 59
Incorrect
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Which of the following conditions manifests hyperkalaemia as one of its symptoms?
Your Answer: Type 1 renal tubular acidosis
Correct Answer: Congenital adrenal hyperplasia
Explanation:Plasma potassium greater than 5.5 mmol/L is hyperkalaemia or elevated plasma potassium level. Among the causes of hyperkalaemia include congenital adrenal hyperplasia.
Congenital adrenal hyperplasia is a general term referring to autosomal recessive disorders involving a deficiency of an enzyme needed in cortisol and/or aldosterone synthesis. The level of cortisol and/or aldosterone deficiency affects the clinical manifestations of congenital adrenal hyperplasia. When it involves hypoaldosteronism, it can result in hyponatremia and hyperkalaemia. While hypercortisolism can cause hypoglycaemia.
The other causes of hyperkalaemia may include renal failure, excess potassium supplementation, Addison’s disease (adrenal insufficiency), renal tubular acidosis (type 4), rhabdomyolysis, burns, trauma, Tumour lysis syndrome, acidosis, and medications such as ACE inhibitors, angiotensin receptor blockers, NSAIDs, beta-blockers, digoxin, and suxamethonium.
Bartter’s syndrome is characterized by hypokalaemic alkalosis with normal to low blood pressure.
Type 1 and 2 renal tubular acidosis both cause hypokalaemia.
Gitelman’s syndrome is a defect of the distal convoluted tubule of the kidney. It causes metabolic alkalosis with hypokalaemia and hypomagnesemia.
And excessive liquorice ingestion causes hypermineralocorticoidism and hypokalaemia as well. Thus, among the choices, only congenital adrenal hyperplasia can cause hyperkalaemia
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 60
Incorrect
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A blood transfusion is given to a 52-year-old woman. She develops chills and rigours shortly after the transfusion begins.
The following are her observations: Temperature 40°C, HR 116 bpm, BP 80/48, SaO 2 97 percent on air.
Which of the following treatments is the most appropriate?Your Answer: Supportive measures and paracetamol
Correct Answer: Stop the transfusion and administer antibiotics
Explanation:Bacterial infections are common in the following situations:
Platelet transfusions are associated with a higher risk of bacterial infection (as platelets are stored at room temperature)
Immersion in a water bath thawed previously frozen components.
Components of red blood cells that have been stored for several weeks
Gram-positive and Gram-negative bacteria have both been linked to transfusion-transmitted bacterial infection, but Gram-negative bacteria are linked to a higher rate of morbidity and mortality.
Yersinia enterocolitica is the most common bacterial organism linked to transfusion-transmitted bacterial infection. This organism can multiply at low temperatures while also utilising iron as a nutrient. As a result, it’s well-suited to proliferating in blood banks.The following are some of the most common clinical signs and symptoms of a bacterial infection transmitted through a blood transfusion. These symptoms usually appear shortly after the transfusion begins:
Fever is very high.
Rigours and chills
Vomiting and nausea
Tachycardia
Hypotension
Collapse of the circulatory systemIf a bacterial infection from a transfusion is suspected, the transfusion should be stopped right away. Blood cultures and a Gram stain should be requested, as well as broad-spectrum antibiotics. In addition, the blood pack should be returned to the blood bank for an urgent culture and Gram-stain.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 61
Incorrect
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Regarding endothelin-1, which of the following statements is INCORRECT:
Your Answer: Endothelin-1 (ET-1) is an extremely potent vasoconstrictor peptide.
Correct Answer: Endothelin-1 release is inhibited by noradrenaline.
Explanation:Endothelin-1 (ET-1) is an extremely potent vasoconstrictor peptide which is released from the endothelium in the presence of many other vasoconstrictors, including angiotensin II, antidiuretic hormone (ADH) and noradrenaline, and may be increased in disease and hypoxia.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 62
Incorrect
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Severe vomiting and diarrhoea were reported by a 25-year-old man. He's dehydrated and needs intravenous fluids to rehydrate. You give him cyclizine as part of his treatment.
What is cyclizine's main mechanism of action?Your Answer: 5-HT 3 receptor antagonism
Correct Answer: Antihistamine action
Explanation:Cyclizine is a piperazine derivative that functions as an antihistamine (H1-receptor antagonist). To prevent nausea and vomiting, it is thought to act on the chemoreceptor trigger zone (CTZ) and the labyrinthine apparatus. It has a lower antimuscarinic effect as well.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 63
Correct
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You're taking a history of a 59-year-old banker who has had heartburn in the past.
Which of the following information about antacids is correct?Your Answer: Magnesium carbonate can reduce the absorption of drugs taken at the same time
Explanation:Antacids such as aluminium hydroxide and magnesium carbonate are commonly used. They’re both water-insoluble and can reduce the absorption of drugs taken together. Allow at least 1-2 hours between taking these antacids and any other medications.
Because it reduces gastrointestinal phosphate absorption, aluminium hydroxide can also be used to treat hyperphosphatemia in patients with renal failure.
Magnesium carbonate has a laxative effect, whereas aluminium hydroxide has a constipating effect.
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This question is part of the following fields:
- Gastrointestinal Pharmacology
- Pharmacology
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Question 64
Incorrect
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A 54-year-old man with a long history of poorly controlled hypertension complains of a headache and vision blurring today. In triage, his blood pressure is 210/192 mmHg. A CT head scan is scheduled to rule out the possibility of an intracranial haemorrhage. You make the diagnosis of hypertensive encephalopathy and rush the patient to reus to begin blood pressure-lowering treatment. He has a history of brittle asthma, for which he has been admitted to the hospital twice in the last year.
Which of the following is the patient's preferred drug treatment?Your Answer: 25% of the systolic pressure over the first hour
Correct Answer: 25% of the mean arterial pressure over the first hour
Explanation:End-organ damage (e.g. encephalopathy, intracranial haemorrhage, acute myocardial infarction or ischaemia, dissection, pulmonary oedema, nephropathy, eclampsia, papilledema, and/or angiopathic haemolytic anaemia) characterises a hypertensive emergency (also known as ‘accelerated hypertension’ or malignant hypertension’ It’s a life-threatening condition that necessitates rapid blood pressure reduction to avoid end-organ damage and a negative outcome.
Hypertensive encephalopathy is a syndrome that includes headaches, seizures, visual changes, and other neurologic symptoms in people who have high blood pressure. It is reversible if treated quickly, but it can progress to coma and death if not treated properly.
Any patient with suspected hypertensive encephalopathy should have an urgent CT scan to rule out an intracranial haemorrhage, as rapid blood pressure reduction could be dangerous in these circumstances.
The drug of choice is labetalol, which reduces blood pressure steadily and consistently without compromising cerebral blood flow.
An initial reduction of approximately 25% in mean arterial pressure (MAP) over an hour should be aimed for, followed by a further controlled MAP reduction over the next 24 hours. In patients who are unable to take beta-blockers, nicardipine can be used as a substitute. -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 65
Correct
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A critically ill 48-year-old individual appears with symptoms and signs of an anaphylactic reaction.
In an allergic reaction, which of the following is an absolute contraindication to the injection of adrenaline?Your Answer: None of the other options
Explanation:Even if the following relevant contraindications exist, adrenaline can be given in life-threatening anaphylactic reactions:
Coronary artery disease (CAD)
Coronary artery disease (CAD) Second stage of labour
Hypertension that is uncontrolled
Severe Ventricular arrhythmias -
This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 66
Correct
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A well recognised adverse effect of metoclopramide is which of the following?
Your Answer: Acute dystonic reaction
Explanation:Side effects of metoclopramide are commonly associated with extrapyramidal effects and hyperprolactinemia. Therefore its use must be limited to short-term use. Metoclopramide can induce acute dystonic reactions which involve facial and skeletal muscle spasms and oculogyric crises. These dystonic effects are more common in the young girls and young women, and in the very old. These symptoms usually occur shortly after starting treatment with this drug and subside within 24 hours of stopping it. Abortion of dystonic attacks can be carried out by injection of an antiparkinsonian drug like procyclidine.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 67
Correct
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A 72-year-old woman presents to your clinic with worsening oedema. She has ischaemic heart disease and heart failure. You decide to add a loop diuretic to her current drug regime to control the oedema. Which of the following is a contraindication to using a loop diuretic?
Your Answer: Anuria
Explanation:Loop diuretics are drugs used to manage and treat fluid overload associated with CHF, liver cirrhosis, and renal disease. The drugs commonly used are:
- Furosemide
- Bumetanide
- Torsemide
- Ethacrynic Acid
Loop diuretics inhibit the Na-K-Cl pump in the ascending loop of Henle, resulting in salt-water excretion. This relieves congestion and reduces oedema.
The contra-indications to the use of loop diuretics are:
1. Anuria
2. Comatose and precomatose states associated with liver cirrhosis
3. Renal failure due to nephrotoxic or hepatotoxic drugs
4. Severe hypokalaemia
5. Severe hyponatremia
6. History of hypersensitivity to furosemide, bumetanide, or torsemide (or sulphonamides)The following conditions or states are not contraindications, but loop diuretics needs to be used cautiously in these conditions:
1. Diabetes (but hyperglycaemia less likely than with thiazides)
2. Gout
3. Hypotension (correct before initiation of treatment)
4. Hypovolaemia (Correct before initiation of treatment) -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 68
Correct
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When an elderly dehydrated patient is moved from a supine to a standing position, her heart rate increases. Which of the following accounts for the increase in heart rate upon standing:
Your Answer: Decreased venous return
Explanation:On standing from a prone position, gravity causes blood to pool in veins in the legs. Central venous pressure (CVP) falls, causing a fall in stroke volume and cardiac output (due to Starling’s law) and thus a fall in blood pressure. Normally this fall in BP is rapidly corrected by the baroreceptor reflex which causes venoconstriction (partially restoring CVP), and an increase in heart rate and contractility, so restoring cardiac output and blood pressure. Impaired autonomic nervous activity in the elderly accounts for the greater likelihood of postural hypotension. Any symptoms of dizziness, blurred vision or syncope is due to a transient fall in cerebral perfusion that occurs before cardiac output and mean arterial pressure (MAP) can be corrected.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 69
Incorrect
-
A 22-year-old student presents with a painful, red and itchy right eye. On examination, there is mild erythema of palpebral conjunctiva, and follicles are visible on eversion of the eyelid. Lid oedema is evident, and you can also see a few petechial subconjunctival haemorrhages. The eye appears watery, and there is no purulent discharge. He has recently recovered from a mild upper respiratory tract infection.
Which of these is the most likely causative organism?
Your Answer: Rhinovirus
Correct Answer: Adenovirus
Explanation:The most frequent cause of red eye is conjunctivitis. It is caused by inflammation of the conjunctiva which can be infective or allergic and accounts for about 35% of all eye problems presenting to general practice.
Viral conjunctivitis is commonly caused by adenoviruses and it is the most common infectious conjunctivitis.
The common bacterial causes of conjunctivitis are Haemophilus influenzae, Streptococcus pneumoniae, and Staphylococcus aureus.
The clinical features of infective conjunctivitis include:
Acute onset of conjunctival erythema
Feeling ‘grittiness’, ‘foreign body’ or ‘burning’ sensation in the eye.
Watering and discharge which may cause transient blurring of visionFeatures of viral conjunctivitis include: watery and non-purulent eye discharge, lid oedema, follicles present on eyelid eversion, petechial subconjunctival haemorrhages and pseudomembranes may be seen on the tarsal conjunctival surfaces.
This patients features are consistent with a viral aetiology, and the most likely causative organism is adenovirus,
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 70
Correct
-
Following an injury sustained during a rugby match, a 16-year-old boy is brought to the Emergency Department by his mother. His forearm appears to be deformed, and you believe he has a distal radius fracture. A numerical rating scale is used to assess his pain, and the triage nurse informs you that he is in moderate pain.'
The RCEM guidance recommends which of the following analgesics for the treatment of moderate pain in a child of this age?Your Answer: Oral codeine phosphate 1 mg/kg
Explanation:According to a 2018 audit conducted by the Royal College of Emergency Medicine (RCEM), the standard of care for children presenting to EDs with fractured limbs has deteriorated, with most patients waiting longer than ever before for pain relief. More than one-tenth of the children who came in with significant pain from a limb fracture received no pain relief at all.
For all patients, including children, the Agency for Health Care Policy and Research (AHCPR) in the United States recommends using the ABCs of pain management:
A – Ask about pain regularly. Assess pain systematically.
B – Believe the patient and family in their reports of pain and what relieves it.
C – Choose pain control options appropriate for the patient, family, and setting.
D – Deliver interventions in a timely, logical, coordinated fashion.
E – Empower patients and their families. Enable patients to control their course to the greatest extent possible.The RCEM guidelines recommend assessing a child’s pain within 15 minutes of arrival. This is a fundamental requirement. For the assessment of pain in children, a variety of rating scales are available; which one is used depends on the child’s age and ability to use the scale. These are some of them:
Faces of Wong-Baker Scale for assessing pain
Scale of numerical evaluation
The behavioural scale is a scale that measures how people behave.The RCEM has provided the following visual guide:
The RCEM has established the following guidelines for when patients in severe pain should receive appropriate analgesia:
100% within 60 minutes of arrival or triage, whichever is earliest
75% within 30 minutes of arrival or triage, whichever is earliest
50% within 20 minutes of arrival or triage, whichever is earliest -
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 71
Incorrect
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Which of the following statements is correct with regards to Klebsiella spp?
Your Answer: They are not usually found in normal human flora.
Correct Answer: They are typically associated with nosocomial infection.
Explanation:Klebsiella is a type of bacteria commonly found in nature. In humans, the bacteria are often present in parts of the digestive tract and respiratory flora, where they do not generally cause problems. They are anaerobic Gram-negative rods. They are usually opportunistic pathogens which cause nosocomial infections, the most common ones being pneumonia and UTI.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 72
Correct
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A 66-year-old female with a history of stroke one year ago presents to the Family Medicine clinic complaining of fatigue, weight loss, and tongue discolouration. On examination, she seems malnourished, her tongue is beefy red, and an ataxic gait pattern is noticed.
Which ONE of the following conditions does this patient most likely have?Your Answer: Vitamin B12 deficiency
Explanation:A history of stroke and poor nutritional status points towards a nutritional deficiency as the most likely cause of her symptoms. The examination would differentiate between Vitamin B12 and Folic acid deficiency as in the former. The patient has a beefy red tongue and symptoms indicating peripheral nervous system involvement or subacute combined spinal cord degeneration. The patient may also have a lemon-yellow skin colour, loss of proprioception and vibratory sense and oral ulceration.
Investigations in B12 deficiency can reveal the following:
1. Macrocytic anaemia
2. Neutropoenia
3. Thrombocytopaenia
4. Blood film: anisocytosis, poikilocytosis
5. Low serum B12
6. Raised serum bilirubin (haemolysis)
7. Intrinsic factor antibodies
8. Positive Schilling test -
This question is part of the following fields:
- Haematology
- Pathology
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Question 73
Incorrect
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The following statements about cross-sectional studies are true EXCEPT?
Your Answer: They can be used to assess the prevalence of a condition
Correct Answer: They can be used to determine the relative risk of a condition
Explanation:The UK national census is an example of a cross-sectional study.
Cross-sectional studies can be used to assess the prevalence of a condition, and support or refute inferences of cause and effect.
Cross-sectional studies are observations of the frequency and characteristics of a disease in a given population at one particular point in time.
Cross-sectional studies do not differentiate between cause and effect and also do not establish the sequence of events.
Cross-sectional studies cannot be used to calculate the relative risk of a condition.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 74
Correct
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A 50-year-old man presents with headaches, lethargy, hypertension, and electrolyte disturbance. A diagnosis of primary hyperaldosteronism is made.
Which biochemical pictures would best support this diagnosis?
Your Answer: Hypokalaemic metabolic alkalosis
Explanation:When there are excessive levels of aldosterone outside of the renin-angiotensin axis, primary hyperaldosteronism occurs. High renin levels will lead to secondary hyperaldosteronism.
The classical presentation of hyperaldosteronism when symptoms are present include:
Hypokalaemia
Metabolic alkalosis
Hypertension
Normal or slightly raised sodium levels -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 75
Correct
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Which of the following statements about propofol is TRUE:
Your Answer: Propofol has some antiemetic action.
Explanation:Propofol has some antiemetic properties. It’s for this reason that it’s used to treat postoperative nausea and vomiting. Propofol is mostly processed in the liver, with the kidneys excreting just around 1% of it unaltered. Propofol, unlike thiopental, does not produce tissue necrosis when it is extravasated. Propofol lowers intracranial pressure via lowering brain metabolic rate and cerebral blood flow. Propofol is thought to be safe for people with bronchial asthma and chronic obstructive pulmonary disease.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 76
Correct
-
Which of the following statements is incorrect regarding the electron transfer system?
Your Answer: The electron transfer system occurs in anaerobic respiration.
Explanation:The electron transfer system is responsible for most of the energy produced during respiration. The is a system of hydrogen carriers located in the inner mitochondrial membrane. Hydrogen is transferred to the electron transfer system via the NADH2molecules produced during glycolysis and the Krebs cycle. As a result, a H+ion gradient is generated across the inner membrane which drives ATP synthase. The final hydrogen acceptor is oxygen and the H+ions and O2 combine to form water.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 77
Incorrect
-
The transport of oxygen from maternal to fetal circulation is made possible by fetal haemoglobin. Which of the statements about fetal haemoglobin (HbF) is also correct?
Your Answer: It has a weaker affinity for oxygen than adult haemoglobin
Correct Answer: The oxygen dissociation curve for foetal haemoglobin is shifted to the left of that of adult haemoglobin
Explanation:Fetal haemoglobin is the most common type of haemoglobin found in the foetus during pregnancy. It transports oxygen from the maternal circulation to the fetal circulation. It can easily bind to oxygen from the maternal circulation because it has a high affinity for oxygen. From 10 to 12 weeks of pregnancy to the first six months after birth, the erythroid precursor cells produce fetal haemoglobin. In comparison to adult haemoglobin, fetal haemoglobin has two alpha and two gamma subunits, whereas adult haemoglobin has two alpha and two beta subunits in its major form.
And, unlike adult haemoglobin, the oxygen dissociation curve of fetal haemoglobin is left-shifted. Myoglobin is an oxygen storage molecule with a very high affinity for oxygen. Only when the partial pressure of oxygen is exceeded does it release oxygen.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 78
Correct
-
Which family of receptors does the glucagon receptor belong?
Your Answer: G-protein coupled receptors
Explanation:Glucagon binds to class B G-protein coupled receptors and activates adenylate cyclase, increasing cAMP intracellularly.
This activates protein kinase A. Protein kinase A phosphorylates and activates important enzymes in target cells.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 79
Incorrect
-
A 30-year-old male presents with easy bruising and bleeding gums, feeling very tired lately, and recurrent chest infections over the past few months. He had glandular fever approximately 6 months ago and feels that his symptoms started after that.
His full blood count today is as follows:
Hb 6.3 g/dl (11.5-14 g/dl)
MCV 90 fl (80-100 fl)
WCC 2.0 x 10 9 /l (4-11 x 10 9 /l)
Platelets 15 x 10 9 /l (150-450 x 10 9 /l)
The SINGLE most likely diagnosis is?Your Answer: Autoimmune haemolytic anaemia
Correct Answer: Aplastic anaemia
Explanation:Aplastic anaemia is a life-threatening failure of haemopoiesis characterised by pancytopenia and hypocellular bone marrow. It is rare and patients present with features of recurrent infections secondary to (leukocytopenia), increased bleeding tendency (secondary to thrombocytopenia) and anaemia. In aplastic anaemia, there is damage to the bone marrow and the haematopoietic stems cells leading to pancytopenia.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 80
Correct
-
Regarding calcium channel blockers, which of the following statements is CORRECT:
Your Answer: Calcium channel blockers inhibit L-type voltage-sensitive calcium channels in arterial smooth muscle causing vasodilation.
Explanation:Calcium channel blockers inhibit L-type voltage-sensitive calcium channels in arterial smooth muscle, causing relaxation and vasodilation (reduction in peripheral vascular resistance). They also block calcium channels within the myocardium and conducting tissues of the heart which produces a negative inotropic effect by reducing calcium influx during the plateau phase of the action potential.
They have a variety of uses, including:
Hypertension
Angina
Atrial fibrillation
Migraine
Calcium channel blockers have been found to be moderately useful in the prevention of migraines. The best evidence is for this is with verapamil. This may be due to the prevention of the arteriolar constriction that is associated with migraine. They are commonly used for this elsewhere in the world but are not currently licensed for this use in the UK.
The following are common side effects of all calcium-channel blockers:
Abdominal pain
Dizziness
Drowsiness
Flushing
Headache
Nausea and vomiting
Palpitations
Peripheral oedema
Skin reactions
Tachycardia
Verapamil is highly negatively inotropic and reduces cardiac output, slows the heart rate and may impair atrioventricular conduction. It may precipitate heart failure, exacerbate conduction disorders, and cause hypotension at high doses and should not be used with beta-blockers. Nifedipine has less myocardial effects than verapamil and has no antiarrhythmic properties but has more influence on the vessels. Nimodipine is used solely for the prevention and treatment of vascular spasm following aneurysmal subarachnoid haemorrhage. -
This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 81
Incorrect
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Which of the following occurs at the transverse thoracic plane:
Your Answer: Azygos vein drains into subclavian vein
Correct Answer: Bifurcation of the trachea
Explanation:A way to help remember the structures transected by the transverse thoracic plane is CLAPTRAP:
C: cardiac plexus
L: ligamentum arteriosum
A: aortic arch (inner concavity)
P: pulmonary trunk
T: tracheal bifurcation (carina)
R: right-to-left movement of the thoracic duct (posterior to the oesophagus)
A: azygos vein drains into superior vena cava
P: pre-vertebral fascia and pre-tracheal fascia end -
This question is part of the following fields:
- Anatomy
- Thorax
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Question 82
Correct
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This anatomic part lies at the heart of the tooth.
Your Answer: The pulp cavity
Explanation:Within the central portion of the tooth lies the dental pulp. The pulp chamber provides mechanical support and functions as a barrier from external stimuli and the oral microbiome. The dental pulp is a unique tissue that is richly innervated and has an extensive microvascular network. Maintaining its vitality increases both the mechanical resistance of the tooth and the long-term survival. The junctional epithelium forms a band around the tooth at the base of the gingival sulcus, sealing off the periodontal tissues from the oral cavity.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 83
Correct
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A 30-year-old woman presents with a history of fever and sore throat. On examination, there is tonsillar exudate and cervical lymphadenopathy and a diagnosis of tonsillitis is made. A course of penicillin is prescribed.
What is the mechanism of action of penicillin?
Your Answer: Inhibition of cell wall synthesis
Explanation:Penicillin is bactericidal and produces its antimicrobial action by preventing cross-linkage between the linear peptidoglycan polymer chains that make up the bacterial cell wall. This action inhibits cell wall synthesis.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 84
Incorrect
-
A 17-year-old male presenting in the department has a history of C3 deficiency.
C3 deficiency is associated with all of the following EXCEPT?Your Answer: Increased susceptibility to infections caused by Haemophilus Influenzae
Correct Answer: Hereditary angioedema
Explanation:C1-inhibitor deficiency is the cause of hereditary angioedema not C3 deficiency,
All the other statements are correct
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 85
Correct
-
In a 7-year-old child with chickenpox, which of the following would you advise the mother NOT to do?
Your Answer: Give ibuprofen for the fever
Explanation:Chickenpox (varicella zoster) is a highly contagious airborne disease and has an incubation period of between 7-21 days. It often has a prodromal phase when there is a fever, aches and headaches, dry cough, and sore throat before onset of rash.
Some recognized complications of chickenpox are:
Orchitis
Hepatitis
Pneumonia
Encephalitis
Infected spots
Otitis media
Myocarditis
Glomerulonephritis
Appendicitis
PancreatitisTreatment is symptomatic and includes using paracetamol to manage fever. There is a link between use of ibuprofen in patients with chicken-pox and necrotizing fasciitis so Ibuprofen should NOT be used.
An emollient and antihistamine can be used to ease the itchy rash and oral hydration is encouraged.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 86
Incorrect
-
An ambulance transports a 72-year-old woman to the Emergency Department. She is confused, has been vomiting and having stomach pains. Digoxin is one of her medications.
Which of the following claims about digoxin is correct?Your Answer: Hyperkalaemia can predispose to digoxin toxicity
Correct Answer: Therapeutic plasma levels are between 1.0-1.5 nmol/l
Explanation:Digoxin is a cardiac glycoside that is used to treat atrial fibrillation and flutter, as well as congestive heart failure. In cardiac myocytes, it works by inhibiting the membrane Na/K ATPase. Through Na/Ca exchange, this raises intracellular sodium concentration and indirectly increases intracellular calcium availability. Increased intracellular calcium levels have both a positive inotropic and negative chronotropic effect.
Digoxin therapeutic plasma levels are typically between 1.0 and 1.5 nmol/l, though higher concentrations may be required, and the value varies between laboratories. At concentrations greater than 2 nmol/l, the risk of toxicity increases dramatically.
In patients with normal renal function, digoxin has a long plasma half-life of 36 to 48 hours. This can take up to 5 days in patients with impaired renal function.
Hypokalaemia, rather than hyperkalaemia, has been shown to increase the risk of digoxin toxicity.
In the treatment of persistent and permanent atrial fibrillation, digoxin is no longer widely used. Beta-blockers, also known as rate-limiting calcium channel blockers, are now the first-line treatment for this condition.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 87
Incorrect
-
Regarding the glomerular filtration barrier, which of the following statements is CORRECT:
Your Answer: Negatively charged molecules are filtered more freely than positively charged ones.
Correct Answer: The main factor determining whether a substance is filtered or not is molecular weight.
Explanation:Molecular weight is the main factor in determining whether a substance is filtered or not – molecules < 7 kDa in molecular weight are filtered freely e.g. glucose, amino acids, urea, ions but larger molecules are increasingly restricted up to 70 kDa, above which filtration is insignificant. Negatively charged molecules are further restricted, as they are repelled by negative charges, particularly in the basement membrane. Albumin has a molecular weight of 69 kDa and is negatively charged, thus only very small amounts are filtered (and all of the filtered albumin is reabsorbed in the proximal tubule), whereas small molecules such as ions, glucose, amino acids and urea pass the filter without hindrance. This means that ultrafiltrate is virtually protein free, but otherwise has an identical composition of that of plasma. The epithelial lining of the Bowman's capsule consists of a single layer of cells called podocytes. The glomerular capillary endothelium is perforated by pores (fenestrations) which allow plasma components with a molecular weight of < 70 kDa to pass freely.
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This question is part of the following fields:
- Physiology
- Renal
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Question 88
Correct
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Question 89
Correct
-
A 35-year-old man, who was feeling unwell after his return from a business trip, was diagnosed with a disease that is known to be transmitted by a vector.
Among the following microorganisms, which of the following has a mode of transmission of being vector-borne?Your Answer: Plasmodium falciparum
Explanation:Plasmodium falciparum is a parasite that is vector-borne which is transmitted by the female Anopheles mosquito.
Bordetella pertussis is transmitted through the respiratory tract, via respiratory droplets or direct contact with infectious secretions.
Mycobacterium tuberculosis is transmitted via inhalation of infected respiratory droplets.
HIV may be transmitted via sexual contact, vertical transmission from mothers to infants, and among injection drug users sharing infected needles, as well as through transfusion of infected blood products.
Treponema pallidum transmission normally occurs during direct sexual contact with an individual who has an active primary or secondary syphilitic lesion.
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 90
Incorrect
-
All of the following statement about the microcirculation are correct except:
Your Answer: Blood flow into the microcirculation is regulated by the sympathetic nervous system.
Correct Answer: Over the capillary bed, there is a net absorption of fluid.
Explanation:The hydrostatic pressure along the length of the capillary is usually greater than plasma oncotic pressure. As a result, there is a small net filtration of fluid from the capillary into the interstitial space. The regulation of blood flow into the microcirculation is via the vasoconstriction of small arterioles, which is activated by the sympathetic nervous system through numerous nerve endings in their walls. Unlike proteins, most ions and small molecules diffuse easily across capillary walls and thus the crystalloid osmotic pressure they exert is roughly the same on either side of the capillary wall. Because the plasma colloid osmotic pressure is higher than interstitial colloid osmotic, fluid is drawn intravascularly. A reduction of hydrostatic capillary pressure and transient increase in absorption of fluid is a result of arteriolar constriction.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 91
Incorrect
-
Regarding cellular respiration, which of the following statements is CORRECT:
Your Answer: Cellular respiration is the process by which cells obtain energy in the form of AMP.
Correct Answer: When fats are used as the primary energy source, an excess of acetyl-CoA is produced.
Explanation:Cellular respiration is the process by which cells obtain energy in the form of adenosine triphosphate (ATP). ATP transfers chemical energy from the energy rich substances in the cell to the cell’s energy requiring reactions e.g. active transport, DNA replication and muscle contraction.Cellular respiration is essentially a three step process: 1) Glycolysis, 2)The Krebs cycle, 3)The electron transfer system.The main respiratory substrate used by cells is 6-carbon glucose. Fats and proteins can also be used as respiratory substrates. When fats are being used as the primary energy source, in the absence of glucose, an excess amount of acetyl-CoA is produced, and is converted into acetone and ketone bodies. This can occur in starvation, fasting or in diabetic ketoacidosis. Proteins are used as an energy source only if protein intake is very high, or if glucose and fat sources are depleted.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 92
Correct
-
Infection with Campylobacter jejuni is one of the most common risk factors for which of the following conditions?
Your Answer: Guillain-Barre syndrome
Explanation:One of the most common risk factors for GBS is infection with Campylobacter jejuni, which causes diarrhoea.
Guillain-Barré syndrome (GBS) is a rare autoimmune disorder in which the body’s immune system attacks the nerves, resulting in muscle weakness and paralysis.
Infection with Streptococcus pyogenes can cause acute glomerulonephritis and rheumatic fever.
Haemolytic uraemic syndrome is commonly linked to E. coli infection.
Following measles infection, subacute sclerosing panencephalitis develops.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 93
Correct
-
Coagulative necrosis is typically seen in which of the following:
Your Answer: Myocardial infarction
Explanation:Coagulative necrosis is the most common form of necrosis characterised by the loss of cell nuclei, but with general preservation of the underlying architecture. Dead tissue is macroscopically pale and firm. This is the classic pattern seen in myocardial infarction.Liquefactive necrosis leads to complete loss of cellular structure and conversion into a soft, semi-solid mass. This is typically seen in the brain following cerebral infarction.Caseous necrosis is most commonly seen in tuberculosis. Histologically, the complete loss of normal tissue architecture is replaced by amorphous, granular and eosinophilic tissue with a variable amount of fat and an appearance reminiscent of cottage cheese.Gangrenous necrosis is necrosis with putrefaction of tissues due to exposure to air (dry gangrene) or infection (wet gangrene).
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This question is part of the following fields:
- Inflammatory Responses
- Pathology
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Question 94
Correct
-
Vitamin D is a group of secosteroids that play a role in calcium and phosphate control. Vitamin D's hormonally active metabolite is 1,25-dihydroxycholecalciferol.
Which of the following actions of 1,25-dihydroxycholecalciferol is a direct action?Your Answer: Increases renal phosphate reabsorption
Explanation:The hormone-active metabolite of vitamin D is 1,25-dihydroxycholecalciferol (commonly known as calcitriol). Its activities raise calcium and phosphate levels in the bloodstream.
The following are the primary effects of 1,25-dihydroxycholecalciferol:
Calcium and phosphate absorption in the small intestine is increased.
Calcium reabsorption in the kidneys is increased.
Increases phosphate reabsorption in the kidneys.
Increases the action of osteoclastic bacteria (increasing calcium and phosphate resorption from bone)
Inhibits the action of 1-alpha-hydroxylase in the kidneys (negative feedback)
Thyroid hormone (parathyroid hormone) Calcium reabsorption in the tubules of the kidneys is increased, but renal phosphate reabsorption is decreased. -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 95
Incorrect
-
You are reviewing a patient following a fall from a horse. You suspect they may have an Erb's palsy as a result of a brachial plexus injury. Regarding Erb's palsy, which one of the following statements is CORRECT:
Your Answer: Erb's palsy classically results from sudden excessive abduction of the arm.
Correct Answer: Erb's palsy may result in loss of sensation of the regimental badge area.
Explanation:Erb’s palsy is caused by damage to the C5 and C6 nerve roots and thus primarily involves the musculocutaneous, suprascapular and axillary nerves. It commonly result from an excessive increase in the angle between the neck and the shoulder e.g. a person thrown from a motorbike or horseback or during a difficult birth. There is loss or weakness of abduction, lateral rotation and flexion of the arm and flexion and supination of the forearm and loss of sensation on the lateral arm. A characteristic ‘Waiter’s tip’ deformity may be present where the limb hangs limply by the side, medially rotated by the unopposed action of pectoralis major with the forearm pronated due to paralysis of the biceps brachii.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 96
Correct
-
A 30-year-old man present to the ED with abdominal pain, nausea and vomiting. It has been present for the past two days.
Which of the following statements regarding diarrhoea and vomiting is true?
Your Answer: E.Coli can cause diarrhoea and renal failure
Explanation:Escherichia coli strain 0157 causes enterohaemorrhagic diarrhoea and can lead to renal failure, haemolytic anaemia and thrombocytopenia.
Norwalk virus is an RNA virus.
Although transmission of rotavirus is primarily through the faeco-oral route, airborne spread has been seen in some cases.
Cryptosporidium are protozoa with acid fast walls and are resistant to both chlorine treatment and conventional filtering methods.
There is no therapy effective in treating cryptosporidium diarrhoea as the protozoa is not susceptible to antibiotics.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 97
Incorrect
-
In the Paediatric Emergency Department, you saw a 6-year-old girl with severe bilateral conjunctivitis. You give her mother some general eye hygiene advice and prescribe chloramphenicol eye drops.
What is the chloramphenicol's mechanism of action?
Your Answer: Disruption of cell membrane function
Correct Answer: Inhibition of protein synthesis
Explanation:Chloramphenicol is a broad-spectrum antibiotic that inhibits bacterial protein synthesis by blocking the 50S subunit of the bacterial ribosome’s peptidyl transferase activity. When administered systemically, it has limited usage due to the potential of significant side effects such as aplastic anaemia, peripheral neuropathy, and optic neuritis. It’s only used to treat typhoid fever and Haemophilus influenzae meningitis, but it’s usually better to use a broad-spectrum cephalosporin.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 98
Correct
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Question 99
Correct
-
What is the main mechanism of action of cyclizine:
Your Answer: Histamine-H1 antagonist
Explanation:Antihistamines e.g. cyclizine, are effective against nausea and vomiting caused by many different conditions, including motion sickness and vertigo. These agents act by inhibiting histamine pathways, and cholinergic pathways involved in transmission from the vestibular apparatus to the vomiting centre. There is no evidence that any one antihistamine is superior to another but their duration of action and incidence of adverse effects differ. Adverse effects include drowsiness and antimuscarinic effects such as blurred vision, dry mouth, urinary retention, constipation and confusion.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 100
Incorrect
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By what mechanism does Vibrio cholerae causes diarrhoea?
Your Answer: Inhibits cyclic adenosine monophosphate (cAMP) production in intestinal epithelial cells
Correct Answer: Increases Cl- secretory channels in crypt cells
Explanation:Cholera is a severe diarrheal illness caused by the Vibrio cholerae bacteria infecting the bowel. Ingesting cholera-infected food or drink is the a way to contract the disease. In the intestinal crypt cells, the toxigenic bacterium Vibrio cholera activates adenylate cyclase and raises cyclic adenosine monophosphate (cAMP).
cAMP stimulates the Cl-secretory channels in crypt cells, resulting in the secretion of chloride with sodium ions and water. The toxin it produces causes the body to secrete massive amounts of water, resulting in diarrhoea and significant fluid and electrolyte loss.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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