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Question 1
Incorrect
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A 23-year-old student presents to the emergency department with a terrible headache, photophobia, and a fever. On her lower limbs, you see a non-blanching purpuric rash. In the department, a lumbar puncture is conducted. What do you think you'll notice on Gram stain:
Your Answer: Gram positive coccobacilli
Correct Answer: Gram negative diplococci
Explanation:Bacterial meningitis and septicaemia are most commonly caused by meningococcal bacteria. The Gram-negative diplococci Neisseria Meningitidis causes meningitis. Gram stain and culture of CSF identify the etiologic organism, N meningitidis. In bacterial meningitis, Gram stain is positive in 70-90% of untreated cases, and culture results are positive in as many as 80% of cases.
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This question is part of the following fields:
- Infections
- Microbiology
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Question 2
Incorrect
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A thyroid function test is done for a 55-year-old woman with non-specific symptoms, the results are shown below:
TSH = 5.2
Free T4 is normal
Free T3 is normal
The most likely diagnosis in this patient is?
Your Answer:
Correct Answer: Subclinical hypothyroidism
Explanation:Hypothyroidism is diagnosed using the results of thyroid function tests (TFTs).
In the early stages of the disease, the earliest biochemical change noticed is a rise in thyroid-stimulating hormone (TSH) levels. Free triiodothyronine (T3) and thyroxine (T4) levels are usually normal.
In primary hypothyroidism, the serum TSH level is usually greater than 10 mU/L, and free T4 levels are below the reference range.
Subclinical hypothyroidism is diagnosed when the serum TSH level is above the reference range, and the free T4 levels are within the reference range. The test should, however, be repeated after 3-6 months to exclude transient causes of raised TSH.
In summary, how to interpret TFTs in cases of suspected hypothyroidism is shown below:
Subclinical hypothyroidism
TSH is raised
Free T4 is normal
Free T3 is normalPrimary hypothyroidism
TSH is raised
Free T4 is lowered
Free T3 is lowered or normalSecondary hypothyroidism
TSH is lowered or normal
Free T4 is lowered
Free T3 is lowered or normal -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 3
Incorrect
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A 22-year-old woman is brought in by ambulance from her GP surgery with suspected meningitis. She has been given a dose of benzylpenicillin already.
What is the mechanism of action of benzylpenicillin? Select ONE answer only.Your Answer:
Correct Answer: Inhibition of cell wall synthesis
Explanation:Penicillins and the other ß-lactam antibiotics are bactericidal. They produce their antimicrobial action by preventing cross-linkage between the linear peptidoglycan polymer chains that make up the bacterial cell wall. They, therefore, inhibit cell wall synthesis.
An overview of the different mechanisms of action of the various types of antimicrobial agents is shown below:
Mechanism of action
Examples
Inhibition of cell wall synthesis
Penicillins
Cephalosporins
Vancomycin
Disruption of cell membrane function
Polymyxins
Nystatin
Amphotericin B
Inhibition of protein synthesis
Macrolides
Aminoglycosides
Tetracyclines
Chloramphenicol
Inhibition of nucleic acid synthesis
Quinolones
Trimethoprim
5-nitroimidazoles
Rifampicin
Anti-metabolic activity
Sulfonamides
Isoniazid -
This question is part of the following fields:
- Infections
- Pharmacology
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Question 4
Incorrect
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Regarding drug interactions with erythromycin, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: Erythromycin decreases plasma levels of warfarin.
Explanation:Erythromycin and clarithromycin inhibit cytochrome P450-mediated metabolism of warfarin, phenytoin and carbamazepine and may lead to accumulation of these drugs. There is an increased risk of myopathy (due to cytochrome P450 enzyme CYP3A4 inhibition) if erythromycin or clarithromycin is taken with atorvastatin or simvastatin. Erythromycin increases plasma concentrations of theophylline, and theophylline may also reduce absorption of oral erythromycin. All macrolides can prolong the QT-interval and concomitant use of drugs that prolong the QT interval is not recommended.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 5
Incorrect
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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:
Correct 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 6
Incorrect
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Cardiac myocytes contract by excitation-contraction coupling, very much like skeletal myocytes. On the other hand, calcium-induced calcium release (CICR) is a mechanism that is unique to Cardiac myocytes. The influx of calcium ions (Ca 2+) into the cell causes a 'calcium spark,' which causes more ions to be released into the cytoplasm.
In CICR, which membrane protein in the sarcoplasmic reticulum is involved?Your Answer:
Correct Answer: Ryanodine receptor
Explanation:Cardiac myocytes contract by excitation-contraction coupling, just like skeletal myocytes. Heart myocytes, on the other hand, utilise a calcium-induced calcium release mechanism that is unique to cardiac muscle (CICR). The influx of calcium ions (Ca2+) into the cell causes a ‘calcium spark,’ which causes more ions to be released into the cytoplasm.
An influx of sodium ions induces an initial depolarisation, much as it does in skeletal muscle; however, in cardiac muscle, the inflow of Ca2+ sustains the depolarisation, allowing it to remain longer. Due to potassium ion (K+) inflow, CICR causes a plateau phase in which the cells remain depolarized for a short time before repolarizing. Skeletal muscle, on the other hand, repolarizes almost instantly.
The release of Ca2+ from the sarcoplasmic reticulum is required for calcium-induced calcium release (CICR). This is mostly accomplished by ryanodine receptors (RyR) on the sarcoplasmic reticulum membrane; Ca2+ binds to RyR, causing additional Ca2+ to be released.
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 7
Incorrect
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Regarding thalassaemia, which of the following statements is CORRECT:
Your Answer:
Correct Answer: Screening for thalassaemia in pregnancy is offered to all pregnant women.
Explanation:Beta thalassemia is caused by mutations in one or both of the beta globin genes. Alpha thalassemia is caused by a deletion or mutation (less commonly) in one or more of the four alpha globin gene copies. β-thalassaemia is more common in the Mediterranean region while α-thalassaemia is more common in the Far East.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 8
Incorrect
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A diagnosis of acute osteomyelitis was made on a patient with a known history of sickle cell disease. He has no joint prosthesis on in-dwelling metal work and no known drug allergies.
Which of the following is most likely the causative agent of the case presented above?Your Answer:
Correct Answer: Salmonella spp .
Explanation:Patients with sickle cell disease are prone to infection of the bone and bone marrow in areas of infarction and necrosis. Although Staphylococcus aureus is the most common cause of osteomyelitis in the general population, studies have shown that in patients with sickle cell disease, the relative incidence of Salmonella osteomyelitis is twice that of staphylococcal infection.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 9
Incorrect
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A 67-year-old female presents with a history of morning stiffness and arthritis of her hand joints. She is being investigated for rheumatoid arthritis.
Which test is most sensitive and specific for this diagnosis?
Your Answer:
Correct Answer: Anti-CCP
Explanation:Anti-cyclic citrullinated peptide (anti-CCP) is an antibody present in 60-80% of rheumatoid arthritis patients. It is measured by enzyme-linked immunosorbent assay (ELISA). It may be present years before the onset of the disease and is associated with a more severe disease course.
While most patients with anti-CCP antibodies are also positive for rheumatoid factor (RF), RF antibody is not specific for rheumatoid arthritis as it can occur in patients with other conditions such as infections and other autoimmune conditions.
ESR, antinuclear antibodies(ANA) and Synovial fluid examination are not specific for rheumatoid arthritis.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 10
Incorrect
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What is the primary route of transmission of Norovirus?
Your Answer:
Correct Answer: Oral-faecal route
Explanation:Norovirus is spread primarily by faecal-oral contact, but it can also be spread through contact with an infected person, ingestion of contaminated food or water, or contact with contaminated surfaces or items.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 11
Incorrect
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You are about to give an antimuscarinic agent to a 55 year-old male patient. Which of the following conditions will make you with stop the administration, since it is a contraindication to antimuscarinic agents?
Your Answer:
Correct Answer: Prostatic enlargement
Explanation:Antimuscarinic medications may impair the contractility of bladder smooth muscle, resulting in acute urine retention in men with BPH, and should be avoided or used with caution.
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This question is part of the following fields:
- Gastrointestinal
- Pharmacology
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Question 12
Incorrect
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Which of the following is NOT an effect of cytokine activity:
Your Answer:
Correct Answer: Opsonisation of bacteria for phagocytosis
Explanation:Cytokines are a family of chemical messengers, secreted by leucocytes, that act over short distances by binding specific receptors on target cell surfaces. They include: interleukins (act between leucocytes), interferons (inhibit replication of viruses within cells and activate macrophages and natural killer cells), growth factors, and tumour necrosis factors (kill tumour cells). Effects include: induction of fever and acute phase response, stimulation of leucocyte differentiation and maturation, leucocyte recruitment and activation and increased antibody production.
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This question is part of the following fields:
- Inflammatory Responses
- Pathology
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Question 13
Incorrect
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Renin is produced by which of the following:
Your Answer:
Correct Answer: Granular cells in the wall of the afferent arteriole
Explanation:Juxtaglomerular cells are specialised smooth muscle cells mainly in the walls of the afferent arterioles (and some in the efferent arterioles) which synthesise renin.
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This question is part of the following fields:
- Physiology
- Renal
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Question 14
Incorrect
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What is the most common application of Nitrates?
Your Answer:
Correct 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 15
Incorrect
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What is the primary mode of action of Enoxaparin?
Your Answer:
Correct Answer: Inhibits factor Xa
Explanation:Heparin acts as an anticoagulant by enhancing the inhibition rate of clotting proteases by antithrombin III impairing normal haemostasis and inhibition of factor Xa. Low molecular weight heparins have a small effect on the activated partial thromboplastin time and strongly inhibit factor Xa. Enoxaparin is derived from porcine heparin that undergoes benzylation followed by alkaline depolymerization.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 16
Incorrect
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A 12-year-old boy presents to you with a history of fever. A rash began as small red dots on the face, scalp, torso, upper arms and legs shortly afterwards and has now progressed to small blisters and pustules. You make a diagnosis of chickenpox.
The following complications of chickenpox is the LEAST likely.
Your Answer:
Correct Answer: Bronchospasm
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
Pancreatitis -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 17
Incorrect
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What is the direct mechanism of action of digoxin as a positive inotrope:
Your Answer:
Correct Answer: Inhibition of Na+/K+ ATPase pump
Explanation:Digoxin directly inhibits membrane Na+/K+ ATPase, which is responsible for Na+/K+ exchange across the myocyte cell membrane. This increases intracellular Na+ and produces a secondary increase in intracellular Ca2+ that increases the force of myocardial contraction. The increase in intracellular Ca2+ occurs because the decreased Na+ gradient across the membrane reduces the extrusion of Ca2+ by the Na+/Ca2+ exchanger that normally occurs during diastole. Digoxin and K+ ions compete for the receptor on the outside of the muscle cell membrane, and so the effects of digoxin may be dangerously increased in hypokalaemia.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 18
Incorrect
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Regarding autoregulation of local blood flow, which of the following statements is CORRECT:
Your Answer:
Correct Answer: An increase in blood flow dilutes locally produced vasodilating factors causing vasoconstriction.
Explanation:Autoregulation is the ability to maintain a constant blood flow despite variations in blood pressure (between 50 – 170 mmHg). It is particularly important in the brain, kidney and heart. There are two main methods contributing to autoregulation:
The myogenic mechanism involves arterial constriction in response to stretching of the vessel wall, probably due to activation of smooth muscle stretch-activated Ca2+channels and Ca2+entry. A reduction in pressure and stretch closes these channels, causing vasodilation.
The second mechanism of autoregulation is due to locally produced vasodilating factors; an increase in blood flow dilutes these factors causing vasoconstriction, whereas decreased blood flow has the opposite effect. -
This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 19
Incorrect
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A known epileptic is transported in status epilepticus by ambulance. On the way to the hospital, she took some diazepam.
Which of the following statements about diazepam is correct?Your Answer:
Correct Answer: It crosses into breast milk
Explanation:Diazepam boosts GABA’s effects, giving it sedative, hypnotic, anxiolytic, anticonvulsant, and muscle-relaxing properties. It can be administered orally, rectally, or intravenously.
With a half-life of 20-100 hours, it is a long-acting benzodiazepine. Midazolam, oxazepam, and alprazolam are examples of short-acting benzodiazepines with a half-life of less than 12 hours (Xanax).
If used in the presence of hepatic impairment, benzodiazepines can cause coma. If treatment is necessary, benzodiazepines with shorter half-lives should be used in lower doses. Diazepam is a sedative that crosses into breast milk and should be avoided by breastfeeding mothers.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 20
Incorrect
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A 25-year-old footballer develops pain and stiffness in his thigh. A diagnosis of iliopsoas syndrome is made.
Iliacus is innervated by which of the following nerves? Select ONE answer only.Your Answer:
Correct Answer: Femoral nerve
Explanation:Iliacus is innervated by the femoral nerve.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 21
Incorrect
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Regarding hypernatraemia, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: In acute severe hypernatraemia, seizures and intracranial vascular haemorrhage can occur as a result of brain cell lysis.
Explanation:Acute severe hypernatraemia is a medical emergency and requires inpatient management in a high dependency setting. Seizures and intracranial vascular haemorrhage as a result of brain cell crenation can occur. The cause is most commonly excessive water loss and the key aspect of treatment is aggressive fluid replacement (typically with normal saline as this is relatively hypotonic). If urine osmolality is low, diabetes insipidus (DI )should be considered and a trial of synthetic ADH given. In patients with known DI, it is essential to ensure synthetic ADH is given parenterally and that close fluid balance is observed.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 22
Incorrect
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Regarding meningococcal meningitis, which of the following statements is CORRECT:
Your Answer:
Correct Answer: Infection occurs most commonly below the age of 5 years.
Explanation:About half of meningococcal disease occurs in children aged less than five years, and babies are at the highest risk because their immune systems have not yet fully developed. There is a second, smaller increase in risk for older adolescents, mainly for social and behavioural reasons. Infection is most common in winter months. Antibiotics should be given as soon as the diagnosis is suspected (ideally cultures should be performed first but this should not delay treatment), and ceftriaxone/cefuroxime is the first line antibiotic. Only healthcare workers who have been directly exposed to large particle droplets/secretions from the respiratory tract of the index case should receive prophylaxis.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 23
Incorrect
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You see a patient in the Emergency Department with features consistent with a diagnosis of type I diabetes mellitus.
Which of these is MOST suggestive of type I diabetes mellitus?
Your Answer:
Correct Answer: History of recent weight loss
Explanation:A history of recent weight loss is very suggestive of an absolute deficiency of insulin seen in type I diabetes mellitus.
An age of onset of less than 20 years makes a diagnosis of type I diabetes mellitus more likely. However, an increasing number of obese children and young people are being diagnosed with type II diabetes.
Microalbuminuria, peripheral neuropathy, and retinopathy all occur in both type I and type II diabetes mellitus. They are not more suggestive of type I DM.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 24
Incorrect
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The myocardium is responsible for creating the force with which the atrial and ventricular muscles contract. It is made up of myocytes, which are heart muscle cells.
Which of the following statements about cardiac muscle anatomy is correct?Your Answer:
Correct Answer: Cardiac myocytes have intercalated discs
Explanation:Typically, granuloma has Langerhan’s cells (large multinucleated cells ) surrounded by epithelioid cell aggregates, T lymphocytes and fibroblasts.
Antigen presenting monocytic cells found in the skin are known as Langerhan’s cells.
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 25
Incorrect
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Which of the following factors decreases insulin secretion:
Your Answer:
Correct Answer: Catecholamines
Explanation:Factors that increase insulin secretion:
↑ Blood glucose
↑ Amino acids
↑ Fatty acids
Glucagon
Secretin
AcetylcholineFactors that decrease insulin secretion:
↓ Blood glucose
Somatostatin
Catecholamines -
This question is part of the following fields:
- Endocrine
- Physiology
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Question 26
Incorrect
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Following the administration of a drug that was started a few months earlier, a patient presents with features of peripheral neuropathy.
Which of the following drugs is most likely to cause peripheral neuropathy?
Your Answer:
Correct Answer: Isoniazid
Explanation:Isoniazid, a first-line agent for the treatment of tuberculosis, has the commonest side effect of peripheral neuropathy. It occurs in up to 20% of patients taking the drug at a dose > 6 mg/kg daily.
Isoniazid combines with pyridoxine (vitamin B6) to form hydrazone, which is excreted in the urine. This causes a deficiency of biologically active pyridoxine leading to peripheral neuropathy.
Peripheral neuropathy of isoniazid is prevented by the co-administration of pyridoxine at a dose of 10 mg for each 100 mg of isoniazid given.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 27
Incorrect
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Regarding benzodiazepines, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: Diazepam is a short-acting benzodiazepine.
Explanation:Diazepam is used to produce mild sedation with amnesia. It is a long-acting drug with active metabolites and a second period of drowsiness can occur several hours after its administration. Midazolam is a water-soluble benzodiazepine that is often used in preference to intravenous diazepam; recovery is faster than from diazepam, but may be significantly longer in the elderly, in patients with a low cardiac output, or after repeated dosing. Midazolam is associated with profound sedation when high doses are given intravenously or when it is used with certain other drugs.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 28
Incorrect
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Regarding the heart sounds in the cardiac cycle, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: The third heart sound is caused by filling of an abnormally stiff ventricle in atrial systole.
Explanation:Heart Sound – Phase of Cardiac Cycle – Mechanical Event:
First heart sound – Start of systole – Caused by closure of the atrioventricular (mitral & tricuspid) valves
Second heart sound – End of systole – Caused by closure of the semilunar (aortic and pulmonary) valves
Third heart sound – Early diastole – Caused by rapid flow of blood from the atria into the ventricles during the ventricular filling phase
Fourth heart sound – Late diastole – Caused by filling of an abnormally stiff ventricle in atrial systole -
This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 29
Incorrect
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Which of the following local anaesthetics has the longest duration of action:
Your Answer:
Correct Answer: Bupivacaine
Explanation:Bupivacaine has a longer duration of action than the other local anaesthetics, up to 8 hours when used for nerve blocks. It has a slow onset, taking up to 30 minutes for full effect. It is often used in lumbar epidural blockade and is particularly suitable for continuous epidural analgesia in labour, or for postoperative pain relief. It is the principal drug used for spinal anaesthesia.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 30
Incorrect
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A 18 year old with known asthma presents himself to ED with acute breathlessness and wheeze for the past 20 minutes. On examination he is tachypneic and tachycardic. His oxygen saturations are 96% on air. What is the first line treatment for acute asthma:
Your Answer:
Correct Answer: Salbutamol
Explanation:High-dose inhaled short-acting beta2-agonists are the first line treatment for acute asthma(salbutamol or terbutaline). Oxygen should only been given to hypoxaemic patients (to maintain oxygen saturations of 94 – 98%). A pressurised metered dose inhaler with spacer device is preferred in patients with moderate to severe asthma (4 puffs initially, followed by 2 puffs every 2 minutes according to response, up to 10 puffs, whole process repeated every 10 – 20 minutes if necessary). The oxygen-driven nebuliser route is recommended for patients with life-threatening features or poorly responsive severe asthma (salbutamol 5 mg at 15 – 30 minute intervals). Continuous nebulisation should be considered in patients with severe acute asthma that is poorly responsive to initial bolus dose (salbutamol at 5 – 10 mg/hour) The intravenous route should be reserved for those in whom inhaled therapy cannot be used reliably.
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This question is part of the following fields:
- Pharmacology
- Respiratory
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SESSION STATS - PERFORMANCE PER SPECIALTY
