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Question 1
Incorrect
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Which one of the following skin disorders is least commonly associated with hypothyroidism?
Your Answer: Paraesthesia
Correct Answer: Pretibial myxoedema
Explanation:Pretibial myxoedema is an infiltrative dermopathy, resulting as a rare complication of Graves’ disease (hyperthyroidism) and very occasionally occurs in non-thyrotoxic Graves’ disease and Hashimoto’s thyroiditis.
Hypothyroidism typically presents with symptoms such as dry skin, brittle hair, and thinning of the outer third of the eyebrows. While skin conditions like dryness and hair changes are common in hypothyroidism due to reduced metabolic activity, acne is also not typically associated with it.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 2
Correct
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Troponin I is inhibited by calcium binding to:
Your Answer: Troponin c
Explanation:At rest troponin I is bound to actin and tropomyosin and covers the site where the myosin head interacts with actin. When calcium enters into the muscle, it binds with troponin C and cause a structural change in troponin I which moves out of the myosin binding site and causes the cross bridges between the actin and myosin filaments to occur.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 3
Incorrect
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A 45-year-old woman has been diagnosed with T1N1M1 malignancy in the left breast, with metastases detectable in the lower thoracic vertebrae and the left lung. Before the initiation of treatment of this patient with trastuzumab, which is the most important investigation to perform?
Your Answer: Liver function tests
Correct Answer: Echo
Explanation:Before the initiation of trastuzumab, an echocardiography is a must to rule out any pre-existing cardiac abnormalities as trastuzumab is cardiotoxic.Trastuzumab (Herceptin) is a monoclonal antibody directed against the HER2/neu receptor. It is used mainly in metastatic breast cancer although some patients with early disease are now also given trastuzumab.Adverse effects include:Flu-like symptoms and diarrhoea are common.Cardiotoxicity: – Risk increases when anthracyclines are used concomitantly. – Trastuzumab-induced cardiac dysfunctions are regarded as less severe and largely reversible because primary cardiomyocyte do not show ultrastructure changes unlike those associated with anthracycline-induced cardiotoxicity. – Primary myocyte injury does not occur in patients who were treated with trastuzumab.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 4
Incorrect
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A 74-year-old man who has been diagnosed with atrial fibrillation and heart failure is being started on digoxin. What is the mechanism of action of digoxin?
Your Answer: Inhibits the Na+/K+ ATPase pump
Correct Answer:
Explanation:Digoxin works by inhibiting the Na+/K+ ATPase pump in cardiac myocytes. Here’s how it works:
- Inhibition of Na+/K+ ATPase: Digoxin binds to and inhibits the Na+/K+ ATPase pump, which is responsible for pumping sodium out of the cell and potassium into the cell.
- Increased intracellular sodium: Inhibition of this pump leads to an increase in intracellular sodium levels.
- Decreased activity of the sodium-calcium exchanger: The increased intracellular sodium reduces the activity of the sodium-calcium exchanger, which normally pumps calcium out of the cell in exchange for sodium.
- Increased intracellular calcium: As a result, intracellular calcium levels rise because less calcium is being extruded from the cell. The increased calcium is then stored in the sarcoplasmic reticulum.
- Enhanced contractility: During each action potential, more calcium is released from the sarcoplasmic reticulum into the cytoplasm, which enhances the contractility of the heart muscle (positive inotropic effect).
By increasing the force of contraction, digoxin helps improve cardiac output in patients with heart failure. Additionally, digoxin has vagomimetic effects, which can help control the heart rate in atrial fibrillation by increasing vagal tone and thereby reducing the conduction velocity through the atrioventricular node.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 5
Incorrect
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Which clotting factor is responsible for stabilization of the fibrin clot by formation of covalent cross-linkages?
Your Answer: Factor XIIa
Correct Answer: Factor XIIIa
Explanation:Factor XIII or fibrin stabilizing factor is an enzyme of the blood coagulation system that crosslinks fibrin. Deficiency of this factor (FXIIID) affects clot stability.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 6
Incorrect
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Erythropoietin is synthesized by which cells of the nephron?
Your Answer: Glomerular epithelial cells
Correct Answer: Tubular interstitial cells
Explanation:Erythropoietin is produced by interstitial fibroblasts in the kidney in close association with peritubular capillary and proximal convoluted tubule. It is also produced in perisinusoidal cells in the liver. While liver production predominates in the fetal and perinatal period, renal production is predominant during adulthood.
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This question is part of the following fields:
- Medicine
- Renal
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Question 7
Incorrect
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Which of the following statements correctly describes a function of the parasympathetic innervation of the GI tract.
Your Answer: Inhibitory efferent vagal innervation causes sphincters to contract.
Correct Answer: Parasympathetic cholinergic activity increases the activity of intestinal smooth muscle
Explanation:The parasympathetic nerves stimulate peristalsis and relax the sphincters; they also stimulate secretion. Acetylcholine is the neurotransmitter of the parasympathetic system.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 8
Incorrect
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Select the correct statement regarding the 4th heart sound, it?
Your Answer: Occurs during isovolumetric ventricular contraction.
Correct Answer: Can be heard in atrial systole.
Explanation:The fourth heart sound is not normally audible in a normal adult. It occurs as a consequence of ventricular hypertrophy. It is caused by filling of the ventricle by atrial systole.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 9
Correct
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A 50-year-old male was brought to the ER after the accidental consumption of 300 ml of diethylene glycol. Blood investigations were suggestive of metabolic acidosis and renal failure. What is the appropriate management in this patient?
Your Answer: Haemodialysis and oral ethanol
Explanation:Among the given options the most appropriate management in this patient would be ethanol and haemodialysis.Ethanol competes with ethylene glycol for alcohol dehydrogenase and thus, helps manage a patient with ethylene glycol toxicity.Ethylene glycol is a type of alcohol used as a coolant or antifreezeFeatures of toxicity are divided into 3 stages:Stage 1: (30 min to 12 hours after exposure) Symptoms similar to alcohol intoxication: confusion, slurred speech, dizziness (CNS depression)Stage 2: (12 – 48 hours after exposure) Metabolic acidosis with a high anion gap and high osmolar gap. Also tachycardia, hypertensionStage 3: (24 – 72 hours after exposure) Acute renal failureManagement has changed in recent times:Fomepizole, an inhibitor of alcohol dehydrogenase, is now used first-line in preference to ethanol.Ethanol has been used for many years works by competing with ethylene glycol for the enzyme alcohol dehydrogenase this limits the formation of toxic metabolites (e.g. glycolaldehyde and glycolic acid) which are responsible for the hemodynamic/metabolic features of poisoning.Haemodialysis has a role in refractory cases.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 10
Correct
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A 73-year-old female is being reviewed in the osteoporosis clinic. She had a fracture of her left hip 5 years ago and was started on alendronate. Following the development of persistent musculoskeletal pain, alendronate was replaced with risedronate, which was also stopped for similar reasons. Strontium ranelate was therefore started but was also stopped due to the development of deep vein thrombosis in the right leg. Her current T-score is -4.1. A decision is made to start a trial of denosumab. What is the mechanism of action of denosumab?
Your Answer: Inhibits RANK ligand, which in turn inhibits the maturation of osteoclasts
Explanation:The principal mechanism by which strontium inhibits osteoclast activity is by enhancing the secretion of osteoprotegerin (OPG) and by reducing the expression of the receptor activator of nuclear factor κB ligand (RANKL) in osteoblasts.Osteoporosis is defined as low bone mineral density caused by altered bone microstructure ultimately predisposing patients to low-impact, fragility fractures.Management:Vitamin D and calcium supplementation should be offered to all women unless the clinician is confident they have adequate calcium intake and are vitamin D repleteAlendronate is the first-line treatment. Around 25% of patients cannot tolerate alendronate, usually due to upper gastrointestinal problems. These patients should be offered risedronate or etidronate.Strontium ranelate and raloxifene are recommended if patients cannot tolerate bisphosphonates.Other medications that are useful in the treatment of osteoporosis are denosumab, teriparatide, raloxifene, etc.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 11
Incorrect
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Majority of gastrinomas are found in the:
Your Answer: Terminal ileum
Correct Answer: Duodenum
Explanation:A gastrinoma is a tumour in the pancreas or duodenum that secretes excess of gastrin leading to ulceration in the duodenum, stomach and the small intestine. It is usually found in the duodenum, although it may arise in the stomach or pancreas. Those occurring in the pancreas have a greater potential for malignancy. Most gastrinomas are found in the gastrinoma triangle; this is bound by the junction of cystic and common bile ducts, junction of the second and third parts of the duodenum, and the junction of the neck and body of the pancreas.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 12
Incorrect
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Almost all of the protein that appears in the stool is:
Your Answer: From partially digested proteins
Correct Answer: Comes from bacteria and cellular debris
Explanation:75% of faecal weight is water. By dry weight 30% of faeces is bacteria,10-20% is fat and 2-3% proteins. Almost all proteins ingested are absorbed in the gut.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 13
Incorrect
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What is the function of cytotoxic T cells?
Your Answer: Attack and destroy cells that have the antigen which deactivated them
Correct Answer: Kill by inserting perforins and by initiating apoptosis
Explanation:Cytotoxic T cells, once activated, approach the infected cell, insert perforins and release granzymes inducing apoptosis.
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This question is part of the following fields:
- Immunology
- Medicine
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Question 14
Correct
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The parietal cells of the stomach secrete which of the following?
Your Answer: Hydrochloric acid
Explanation:Parietal cells are the epithelial cells that secrete hydrochloric acid (HCl) and intrinsic factor. These cells are located in the gastric glands found in the lining of the fundus and in the body of the stomach.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 15
Incorrect
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Which factors increase the end-diastolic volume?
Your Answer: Standing
Correct Answer: Constriction of veins
Explanation:End diastolic volume is also known as preload. It is the amount of blood the heart contracts against. Constriction of veins will decrease venous pooling and increase venous return, hence increasing the end diastolic volume. Standing will increase venous pooling hence decreasing venous return and end diastolic volume. Raised intrapericardial pressure will also decrease venous return and hence end diastolic volume.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 16
Incorrect
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What is the most important source of heat production in the body?
Your Answer: Epinephrine secretion
Correct Answer: Skeletal muscle contraction
Explanation:Thermogenesis is the process by which organisms produce heat. Through skeletal muscle contraction, or shivering, ATP is converted into kinetic energy, some of which converts into heat. These muscle contractions produce about 70% of total body heat.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 17
Incorrect
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Which of the following supplies the AV node?
Your Answer: Left coronary artery
Correct Answer: Right coronary artery
Explanation:The AV node is supplied by the right coronary artery near the origin of the posterior IV artery.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 18
Incorrect
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Which of the following is least recognised as a potential complication of acromegaly?
Your Answer: Diabetes mellitus
Correct Answer: Mental retardation
Explanation:Acromegaly is a condition that results from excess growth hormone (GH) after the growth plates have closed. It is typically due to the pituitary gland producing too much growth hormone. In more than 95% of people the excess production is due to a benign tumour, known as a pituitary adenoma. The condition is not inherited.Complications:Severe headacheArthritis and carpal tunnel syndromeEnlarged heartLiver fibrosis and bile duct hyperplasiaHypertensionDiabetes mellitus (excess of GH leads to insulin resistance)Heart failureKidney failureColorectal cancerCompression of the optic chiasm leading to loss of vision in the outer visual fields (typically bitemporal hemianopia.)Increased palmar sweating and sebum production over the face (seborrhoea) are clinical indicators of active GH-producing pituitary tumours.hypertensiondiabetes (>10%)cardiomyopathycolorectal cancer
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 19
Incorrect
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Which receptor type is associated with bronchial muscle relaxation?
Your Answer: β1
Correct Answer: β2
Explanation:β2-adrenoceptors are widely distributed in the respiratory tract. When they are activated, an intracellular response induces the activation of cyclic AMP; this, in turn, produces airway relaxation through phosphorylation of muscle regulatory proteins and modification of cellular Ca2+concentrations.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 20
Incorrect
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A 22 year old man who has recently returned from a trip to Far East presents with sore eyes and symmetrical joint pain in his knees, ankles and feet. Labs reveal an elevated ESR. The synovial fluid aspirate is sterile and has a high neutrophil count. What is the most likely diagnosis?
Your Answer: Rheumatoid arthritis
Correct Answer: Reactive arthropathy
Explanation:Reactive arthritis, (formerly known as Reiter’s syndrome), is an autoimmune condition that occurs after a bacterial infection of the gastrointestinal or urinary tract. It is categorized as a seronegative spondylarthritis because of its association with HLA-B27. Reactive arthritis primarily affects young men and usually presents with musculoskeletal or extra‑articular symptoms. The characteristic triad consists of arthritis, conjunctivitis, and urethritis. Symmetric lower limb arthropathy and a sterile joint aspirate points towards reactive arthropathy.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 21
Correct
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Glucose transport in the brain is mediated by:
Your Answer: GLUT 1
Explanation:The facilitative glucose transporter mediates the transport of glucose from blood into neurons and glia in the brain. The primary isoforms in the brain are GLUT1 detected at high concentrations.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 22
Correct
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Presence of which of the following indicates a worse prognosis in rheumatoid arthritis?
Your Answer: Anti-CCP antibodies
Explanation:Rheumatoid arthritis is both common and chronic, with significant consequences for multiple organ systems. Anti-cyclic citrullinated peptide (anti-CCP) antibody testing is particularly useful in the diagnosis of rheumatoid arthritis, with high specificity, presence early in the disease process, and ability to identify patients who are likely to have severe disease and irreversible damage. However, its sensitivity is low, and a negative result does not exclude disease. Anti-CCP antibodies have not been found at a significant frequency in other diseases to date, and are more specific than rheumatoid factor for detecting rheumatoid arthritis. The other factors that are mentioned do not play a key prognostic role.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 23
Correct
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The choroid plexus:
Your Answer: All are true
Explanation:The choroid plexus is a vascular structure found in all cerebral ventricles. The functional unit of the choroid plexus, composed of a capillary, enveloped by a layer of differentiated ependymal epithelium. Unlike the capillaries that form the blood-brain barrier, choroid plexus capillaries are fenestrated and have no tight junctions. The endothelium, therefore, does not form a barrier to the movement of small molecules. Instead, the blood-CSF barrier at the choroid plexus is formed by the epithelial cells and the tight junctions that link them.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 24
Incorrect
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Question 25
Incorrect
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Digoxin causes:
Your Answer: Na/k ATPase stimulation
Correct Answer: Increase in cytosolic calcium concentration
Explanation:Digoxin is a positive inotrope which inhibits NA/K ATPase, increases cardiac contractility and can cause hypokalaemia.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 26
Incorrect
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A 68 year old man presents with acute symptoms of gout on his first metatarsophalangeal joint. Which option best explains the underlying mechanism of gout?
Your Answer: Increased endogenous production of uric acid
Correct Answer: Decreased renal excretion of uric acid
Explanation:Primary gout is related more often to underexcretion of uric acid or overproduction.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 27
Incorrect
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Where are the cell bodies of preganglionic neurons located?
Your Answer: Spinothalamic tract
Correct Answer: Lateral column
Explanation:The cell bodies of the preganglionic neurons are located in the lateral grey column of the spinal cord and in the motor nuclei of the 3rd, 7th, 9th and 10th cranial nerves.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 28
Incorrect
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A 23 year old male presents with a history of lower back pain for the last one year. Presence of which of the following features most likely points towards ankylosing spondylitis?
Your Answer: Presence of HLA-B27 antigen on tissue typing
Correct Answer: Bilateral erosion of sacroiliac joints on X-ray
Explanation:Bilateral erosions of the sacroiliac joints on pelvic radiographs of patients with ankylosing spondylitis are an important feature of the modified New York classification criteria. Although HLA-B27 is commonly associated with AS, it can also be found in normal individuals. Back stiffness is worse in the morning and gets better as the day progresses. Tenderness and limited lumbar motion can be associated with other spine problems as well and is not characteristic of rheumatoid arthritis.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 29
Correct
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A 55 year old female presents with progressive dyspnoea, dry cough and fever. She started methotrexate therapy six weeks ago. The current regimen includes methotrexate 15 mg/ week, folic acid 5 mg/day and aspirin 75 mg/day. There is no history of any other chronic illness. Vitals are as follows: Temp: 37.8C, pulse: 100 beats/min, BP: 110/80mmHg and SaO2: 90% on air. Examination reveals synovitis in both wrists, and metacarpophalangeal joints. On auscultation, there are scattered crepitations. Blood test reports are given below:Haemoglobin: 13.1g/dl (13.0 – 18.0 g/dL)WBC: 8.2 x109/l (4 – 11 x 109/l)Neutrophils: 5.1×109/l (1.5 – 7 x 109/l)Platelets: 280 x109/l (150 – 400 x 109/L)ESR: 48 mm/hr (0 – 30 mm/1st hr)Urea, electrolytes and creatinine: normalCXR: patchy airspace shadows bilaterallyWhat is the most likely diagnosis?
Your Answer: Methotrexate pneumonitis
Explanation:Pneumonitis is a serious and unpredictable side-effect of treatment with methotrexate (MTX) that may become life-threatening. The typical clinical symptoms include progressive shortness of breath and cough, often associated with fever. Hypoxaemia and tachypnoea are always present and crackles are frequently audible. Chest radiography reveals a diffuse interstitial or mixed interstitial and alveolar infiltrate, with a predilection for the lower lung fields. Pulmonary function tests show a restrictive pattern with diminished diffusion capacity. Lung biopsy reveals cellular interstitial infiltrates, granulomas or a diffuse alveolar damage pattern accompanied by perivascular inflammation. Most patients present in the first few months of starting methotrexate. It is important that all patients receiving methotrexate be educated concerning this potential adverse reaction and instructed to contact their physicians should significant new pulmonary symptoms develop while undergoing therapy. If methotrexate pneumonitis is suspected, methotrexate should be discontinued, supportive measures instituted and careful examination for different causes of respiratory distress conducted. This may be treated with corticosteroids once underlying infection has been excluded.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 30
Incorrect
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Which of the following is a function of Vitamin C?
Your Answer: Found in the psin proteins (rhodopsin and iodopsin) in the retina
Correct Answer: Hydroxylation of proline to hydroxyproline for collagen synthesis
Explanation:Vitamin C acts as an electron donor for eight different enzymes: Three enzymes (prolyl-3-hydroxylase, prolyl-4-hydroxylase, and lysyl hydroxylase) that are required for the hydroxylation of proline and lysine in the synthesis of collagen.
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This question is part of the following fields:
- Haematology
- Medicine
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SESSION STATS - PERFORMANCE PER SPECIALTY
