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Question 1
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 2
Correct
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Regarding cellular respiration, which of the following statements is CORRECT:
Your 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 3
Correct
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A 24-year-old waiter cuts his hand on a dropped plate that smashed and damages the nerve that innervates opponens digiti minimi.
The opponens digiti minimi muscle is innervated by which of the following nerves? Select ONE answer only.Your Answer: The deep branch of the ulnar nerve
Explanation:Opponens digiti minimi is a triangular-shaped muscle in the hand that forms part of the hypothenar eminence. It originates from the hook of the hamate bone and the flexor retinaculum and inserts into the medial border of the 5thmetacarpal.
Opponens digiti minimi is innervated by the deep branch of the ulnar nerve and receives its blood supply from the ulnar artery.
Opponens digiti minimi draws the fifth metacarpal bone anteriorly and rotates it, bringing the fifth digiti into opposition with the thumb. -
This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 4
Correct
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If the ejection fraction increases, there will be a decrease in:
Your Answer: End-systolic volume
Explanation:An increase in ejection fraction means that a higher fraction of the end-diastolic volume is ejected in the stroke volume (e.g. because of the administration of a positive inotropic agent). When this situation occurs, the volume remaining in the ventricle after systole, the end-systolic volume, will be reduced. Cardiac output, stroke volume, and mean arterial pressure will be increased.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 5
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 6
Correct
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Which of the following side effects would you least associated with ciprofloxacin:
Your Answer: Folate deficiency
Explanation:Common side effects include diarrhoea, dizziness, headache, nausea and vomiting.
Other adverse effects include: Tendon damage (including rupture), Seizures (in patients with and without epilepsy), QT-interval prolongation, Photosensitivity and Antibiotic-associated colitis -
This question is part of the following fields:
- Infections
- Pharmacology
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Question 7
Correct
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A 20-year-old with type I diabetes mellitus has an episode of hypoglycaemia following inadvertent administration of too much insulin.
The mechanism by which insulin causes glucose to be transported into cells is?
Your Answer: Facilitated diffusion
Explanation:The only mechanism by which insulin facilitates uptake of glucose into cells is by facilitated diffusion through a family of hexose transporters.
The major transporter used for glucose uptake is GLUT4. GLUT4 is made available in the plasma membrane by the action of insulin.
When insulin concentrations are low, GLUT4 transporters are present in cytoplasmic vesicles, where they are cannot be used for transporting glucose. -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 8
Correct
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A patient suffers from an injury and as a consequence, is unable to externally rotate his femur when his hip is extended. You suspect a nerve injury to the obturator internus muscle. Which of the following nerves innervate the obturator internus muscle?
Your Answer: Obturator internus nerve
Explanation:The obturator internus is innervated by the obturator internus nerve (L5–S2), a branch of sacral plexus.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 9
Correct
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Among the following infectious diseases, which is typically considered to have an incubation period of 3 weeks and longer?
Your Answer: Infectious mononucleosis
Explanation:Infectious mononucleosis is caused by Epstein-Barr virus (EBV). The incubation period for EBV varies from 2 weeks to 2 months.
The usual incubation period for rubella is 14 days; with a range of 12 to 23 days.
Gonorrhoea has a short incubation period of approximately 2 to 7 days.
The mumps virus can be isolated from infected saliva and swabs rubbed over the Stensen’s duct from 9 days before onset of symptoms until 8 days after parotitis appears.
Scarlet fever, which appears within 1 to 2 days after bacterial infection, is characterized by a diffuse red rash that appears on the upper chest and spreads to the trunk and extremities. The rash disappears over the next 5 to
7 days and is followed by desquamation. -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 10
Correct
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Which of the following is the most common cause of hyperthyroidism:
Your Answer: Graves disease
Explanation:Graves disease is the most common cause of hyperthyroidism. It is an autoimmune disease in which autoantibodies against TSH receptors are produced. These antibodies bind to and stimulate these TSH receptors leading to an excess production of thyroid hormones. Therefore, the signs and symptoms of Graves disease are the same as those of hyperthyroidism, reflecting the actions of increased circulating levels of thyroid hormones: increased heat production, weight loss, increased 02 consumption and cardiac output and exophthalmos (bulging eyes, not drooping eyelids). TSH levels will be decreased (not increased) as a result of the negative feedback effect of increased T3 levels on the anterior pituitary.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 11
Correct
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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 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 12
Correct
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A 15-year-old male is admitted to a rehabilitation centre with a history of multiple strokes, myopathy and learning disabilities since childhood. He is under the care of a multidisciplinary team, and his genetic testing reports show the presence of a mitochondrial disorder.
Which one of the following diseases does this patient most likely have?Your Answer: MELAS
Explanation:Mitochondrial diseases are a group of disorders caused by dysfunctional mitochondria. Most cases are maternally inherited, as we inherit our mitochondrial DNA from our mothers only, although mutations in nuclear DNA cause some cases.
Examples of Mitochondrial Diseases include:
1. Mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS)
2. Mitochondrial epilepsy with ragged red fibres (MERRF)
3. Leber’s hereditary optic neuropathy (LHON)
4. Diabetes mellitus and deafness (DAD)
5. Neuropathy, ataxia, retinitis pigmentosa, and ptosis (NARP)
6. Leigh syndrome (subacute sclerosing encephalopathy).Red-green colour blindness and G6PD deficiency have an X-linked recessive pattern of inheritance.
Tay-Sachs Disease and spinal muscular atrophy have an autosomal recessive pattern of inheritance.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 13
Correct
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A 78-year-old male presents to the Orthopaedic clinic with lower back pain for the past month. His past medical history reveals a history of cancer. After examination, you diagnose Metastatic Spinal Cord Compression (MSCC).
Which one of the following cancers is this patient most likely to have had?Your Answer: Prostate cancer
Explanation:Compression of the thecal sac causes metastatic Spinal Cord Compression (MSCC) due to a Metastatic tumour and its components. It can cause symptoms of limb weakness, sensory disturbances and back pain depending on the extent and level of Compression.
The most common source of a tumour causing MSCC is a prostate carcinoma that metastasized to the spinal cord via the vertebral venous plexus.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 14
Correct
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Regarding relationships between two variables, what does a negative correlation coefficient indicate:
Your Answer: The two variables are inversely related
Explanation:A negative correlation coefficient means that the two variables are inversely related e.g. socio-economic class and mortality.
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 15
Correct
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A 30-year-old woman was involved in a road traffic accident and had a class I haemorrhage.
Which physiological parameter is consistent with a diagnosis of class I haemorrhage?
Your Answer: Increased pulse pressure
Explanation:There are 4 classes of haemorrhage. Classification is based on clinical signs and physiological parameters.
In CLASS I:Blood loss (ml) is < or = 750
Blood loss(% blood volume) < or = 15%
Pulse rate (bpm) is <100
Respiratory rate is 14-20
Urine output (ml/hr) is >30
Pulse pressure is normal or increased
Systolic BP is normal
CNS/mental status patient is slightly anxiousIn CLASS II:
Blood loss (ml) is 750 – 1500
Blood loss(% blood volume) is 15 – 30%
Pulse rate (bpm) is 100 – 120
Respiratory rate is 20-30
Urine output (ml/hr) is 20-30
Pulse pressure is decreased
Systolic BP is normal
CNS/mental status patient is mildly anxiousIn CLASS III:
Blood loss (ml) is 1500 – 2000
Blood loss(% blood volume) is 30- 40%
Pulse rate (bpm) is 120 – 140
Respiratory rate is 30-40
Urine output (ml/hr) is 5-15
Pulse pressure is decreased
Systolic BP is decreased
CNS/mental status patient is anxious, confusedIn CLASS IV:
Blood loss (ml) is >2000
Blood loss(% blood volume) is >40%
Pulse rate (bpm) is >140
Respiratory rate is >40
Urine output (ml/hr) is negligible
Pulse pressure is decreased
Systolic BP is decreased
CNS/mental status patient is confused, lethargic -
This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
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Question 16
Correct
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Superficial fibular nerve palsy results in which of the following clinical features:
Your Answer: Loss of eversion of the foot
Explanation:Damage to the superficial fibular nerve results in loss of eversion of the foot and loss of sensation over the lower anterolateral leg and the dorsum of the foot.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 17
Correct
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An outbreak of acute pneumonia occurs in military recruits living in one barrack and only in those persons located near the air conditioner. Epidemiologic surveillance results in isolation of the causal organism from the patients and from the drip pans of the air conditioner. The organism is weakly Gram-negative. The most likely organism is:
Your Answer: Legionella pneumophila
Explanation:Legionella pneumophilais a Gram negative bacterium that is found in natural water supplies and in the soil, transmitted predominantly via inhalation of aerosols generated from contaminated water (direct person-to-person spread of infected patients does not occur). It is the cause of Legionnaires’ disease. Outbreaks of Legionnaires’ disease have been linked to poorly maintained air conditioning systems, whirlpool spas and hot tubs.
The clinical features of the pneumonic form of Legionnaires’ disease include:
Mild flu-like prodrome for 1-3 days
Cough (usually non-productive and occurs in approximately 90%)
Pleuritic chest pain
Haemoptysis
Headache
Nausea, vomiting and diarrhoea
Anorexia
Legionella pneumophilainfections can be successfully treated with macrolide antibiotics, such as erythromycin, or quinolones, such as ciprofloxacin. Tetracyclines, such as doxycycline, can also be used.
The syndrome of inappropriate antidiuretic hormone secretion (SIADH) can occur with Legionnaires’ disease and will result in hyponatraemia as is seen in this case.
Legionella pneumophilainfections are resistant to amoxicillin but can be successfully treated with macrolide antibiotics, such as erythromycin, or quinolones, such as ciprofloxacin. Tetracyclines, such as doxycycline, can also be used. The majority of cases of Legionnaires’ disease are caused by Legionella pneumophila, however many other species of Legionella have been identified.
Legionella longbeachae is another less commonly encountered species that has also been implicated in outbreaks. It is predominantly found in soil and potting compost, and has caused outbreaks of Pontiac fever, the non-respiratory and less severe variant of Legionnaires’ disease. -
This question is part of the following fields:
- Microbiology
- Pathogens
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Question 18
Correct
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Clostridium tetani causes which of the following infectious diseases:
Your Answer: Tetanus
Explanation:Clostridium tetani causes tetanus.
Scarlet fever is caused by Streptococcus pyogenes.
Toxic shock syndrome is caused by Staphylococcus aureus or Streptococcus pyogenes.
Gas gangrene is primarily caused by Clostridium perfringens.
Pseudomembranous colitis is commonly caused by Clostridium difficile. -
This question is part of the following fields:
- Microbiology
- Pathogens
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Question 19
Correct
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Regarding Clostridium difficile, which of the following statements is CORRECT:
Your Answer: It is normally found in gut flora.
Explanation:C. difficile is normally found in the gut flora but its growth is normally suppressed by more dominant anaerobes. It has exotoxin-mediated effects causing profuse diarrhoea. Oral clindamycin (a broad spectrum antibiotic) is commonly implicated in precipitating C. difficile colitis; first line treatment is with oral metronidazole. Tetanolysin is a toxin produced by Clostridium tetani bacteria.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 20
Correct
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In which of the following would you NOT typically see a neutropaenia:
Your Answer: Asplenism
Explanation:Causes of neutropaenia:
Drug-induced (e.g. chemotherapy, chloramphenicol, co-trimoxazole, phenytoin, carbamazepine, carbimazole, furosemide, chloroquine, clozapine, some DMARDs)
Benign (racial or familial)
Cyclical
Immune (e.g. SLE, Felty’s syndrome, hypersensitivity and anaphylaxis)
Leukaemia
Infections (e.g. HIV, hepatitis, fulminant bacterial infection)
General Pancytopaenia
Hypersplenism, aplastic anaemia, malignant infiltration of bone marrow, megaloblastic anaemia, chemotherapy, myelodysplasia -
This question is part of the following fields:
- Immune Responses
- Pathology
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Question 21
Incorrect
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You are about to perform an emergency pericardiocentesis on a 26-year-old male who was involved in a car accident and is suspected of having cardiac tamponade due to signs of hypotension, muffled heart sounds, and distended neck veins. Where should you insert the needle to relieve tamponade?
Your Answer: Medial left sixth intercostal space
Correct Answer: Inferior and to the left of the xiphochondral junction
Explanation:Pericardiocentesis is a procedure that removes excess fluid from the pericardium. As a result, it’s used in cases of cardiac tamponade, which occurs when there’s too much fluid in the space around the heart.
During the procedure, a needle and a small catheter are inserted 1 to 2 cm inferior and to the left of the xiphochondral junction into the pericardial cavity.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 22
Correct
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The risk of renal impairment in a patient on ACE inhibitor therapy is increased by concomitant treatment with which of the following drug classes:
Your Answer: NSAIDs
Explanation:Concomitant treatment with NSAIDs increases the risk of renal damage, and with potassium-sparing diuretics (or potassium-containing salt substitutes) increases the risk of hyperkalaemia. Hyperkalaemia and other side effects of ACE inhibitors are more common in the elderly and in those with impaired renal function and the dose may need to be reduced.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 23
Correct
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Regarding hepatitis B, which of the following statements is CORRECT:
Your Answer: Chronic hepatitis B infection is indicated by the persistence of HBsAg for more than 6 months.
Explanation:Chronic hepatitis B infection is indicated by the persistence of HBsAg for more than 6 months. Hepatitis B has a long incubation period of about 2 – 6 months. Hepatitis B vaccine has recently been introduced to the routine childhood immunisation schedule – given at 2, 3 and 4 months. It is also given to babies born to hepatitis B infected mothers at birth, four weeks and 12 months old. Treatment of acute hepatitis is supportive. Treatment with antivirals should be considered in chronic infection as responders have a reduced risk of liver damage and liver cancer in the long term.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 24
Correct
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A 79-year-old male had a humeral shaft fracture during a road traffic accident and is being followed up in a fracture clinic. He complains of inability to use the limb 6 months after the injury. X-rays of that arm shows non union of his fracture.
All the following are responsible for this non-union EXCEPT?Your Answer: Osteoporosis
Explanation:An imbalance between bone resorption and formation is Osteoporosis. In normal bone, formation and resorption are roughly equal, and the density of bone matrix remains constant but there is more resorption in osteoporosis and the matrix density reduces and bones become weaker. Fractures are more likely to occur but healing is unaffected.
Non-union of a fracture occurs when the two sides of a fracture fail to unite after 6 months. Causes include: infection, movement at the fracture site, avascular necrosis, tissue interposed between the fracture and gross misalignment.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 25
Correct
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Question 26
Correct
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A 30-year-old man suffers from an open fracture of his forearm. As a consequence of his injury, the nerve that innervates the pronator quadratus muscle was severed.
Which of the following statements regarding the pronator quadratus muscle is considered correct?Your Answer: Its deep fibres bind the radius and ulna together
Explanation:Pronator quadratus is a deep-seated, short, flat, and quadrilateral muscle with fibres running in a parallel direction.
It arises from the oblique ridge on the anterior surface of the distal fourth of the Ulna. It is inserted in lateral border and anterior surface of the distal fourth of the radius. It is innervated by the anterior interosseous nerve, a branch of the median nerve (C8-T1). It is vascularized by the anterior interosseous artery.
The action of the pronator quadratus muscle along with the pronator teres result in the pronation of the radioulnar joint. Contraction of this muscle pulls the distal end of the radius over the ulna, resulting in the pronation of the radioulnar joint
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 27
Correct
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Which of the following is not true regarding the structure and function of glomerular filtration membrane?
Your Answer: The absence of a basement membrane reduces impedance to filtration
Explanation:The glomerular filtration membrane is composed of fenestrated capillary endothelium, basement membrane, and filtration slits. It is an organized, semipermeable membrane preventing the passage of most of the proteins into the urine.
The anatomical arrangement of the glomerular filtration membrane maximizes the surface area available for filtration. The arrangement of its arterioles results in high hydrostatic pressures and facilitates filtration.
Fenestrated capillary endothelium of the glomerular filtration membrane is with relatively large pores. It allows the free movement of plasma proteins and solutes but still restricts the movement of blood cells.
Filtration slits are the smallest filters and restrict the movement of plasma proteins but still allow free movement of ions and nutrients.
The glomerular basement membrane (GBM) is a critical component of the glomerular filtration membrane. Thus, it is not true that its absence will reduce the resistance of flow. The basement membrane is true to be more selective and contains negatively charged glycoproteins. However, it still allows free passage of water, nutrients, and ions. Severe structural abnormalities of the GBM can result in protein (albumin) leakage.
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 28
Correct
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A patient diagnosed with cranial nerve palsy exhibits asymmetrical movement of the palate, nasal regurgitation of food, and nasal quality to the voice.
Which of the following cranial nerves is most likely responsible for the aforementioned features?Your Answer: Vagus nerve
Explanation:The vagus nerve, ‘the wanderer’, contains motor fibres (to the palate and vocal cords), sensory components (posterior and floor of external acoustic meatus) and visceral afferent and efferent fibres.
Palatal weakness can cause nasal speech and nasal regurgitation of food. The palate moves asymmetrically when the patient says ‘ahh’. Recurrent nerve palsy results in hoarseness, loss of volume and ‘bovine cough’.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 29
Incorrect
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A 30-year-old man presents with diarrhoea, fever, vomiting, and abdominal cramps. A stool culture was ordered and showed growth of Salmonella spp.
Among the following serotypes of Salmonella spp., which is considered to be the most common cause of salmonella gastroenteritis?Your Answer: Serotype B
Correct Answer: Serotype D
Explanation:A common cause of gastroenteritis, Salmonella enteritidis, and Salmonella typhi, which causes enteric fever, are both group D. Therefore, serotype D Salmonella species are most commonly associated with gastroenteritis.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 30
Incorrect
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The ventilation over perfusion ratio is highest at the apex of the lung. What is the approximate V/Q ratio at this area?
Your Answer: 2.1
Correct Answer: 3.3
Explanation:The ventilation/perfusion ratio (V/Q ratio) is a ratio used to assess the efficiency and adequacy of the matching ventilation and perfusion. The ideal V/Q ratio is 1.
Any mismatch between ventilation and perfusion will be evident in the V/Q ratio. If perfusion is normal but ventilation is reduced, the V/Q ratio will be less than 1, whereas if ventilation is normal, but perfusion is reduced, the V/Q ratio will be greater than 1.
If the alveoli were ventilated but not perfused at all, then the V/Q ratio would be infinity. The V/Q ratio is also affected by location. The various areas of the lungs have a different V/Q ratio since ventilation and perfusion increase from the apex to the base of the lungs. The apex of the lungs has a V/Q ratio of approximately 3.3.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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SESSION STATS - PERFORMANCE PER SPECIALTY
