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Question 1
Correct
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The petrous part of the internal carotid artery is located inside of which cranial bone?
Your Answer: Temporal
Explanation:The petrous segment, or C2, of the internal carotid is that which is inside the petrous part of the temporal bone. This segment extends until the foramen lacerum. The petrous portion classically has three sections: an ascending, or vertical portion; the genu, or bend; and the horizontal portion.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 2
Incorrect
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A 76-year-old woman is diagnosed with diabetes mellitus after a urine test revealed she has glucosuria. Glucosuria may occur due to inadequate glucose reabsorption at:
Your Answer: Collecting duct
Correct Answer: Proximal convoluted tubule
Explanation:Glucose is reabsorbed almost 100% via sodium–glucose transport proteins (apical) and GLUT (basolateral) in the proximal convoluted tubule. Glycosuria or glucosuria is a condition of osmotic diuresis typical in those suffering from diabetes mellitus. Due to a lack of insulin, plasma glucose levels are above normal. This leads to saturation of receptors in the kidneys and glycosuria usually at plasma glucose levels above 11 mmol/l. Rarely, glycosuria is due to an intrinsic problem with glucose reabsorption within the kidneys (such as Fanconi syndrome), producing a condition termed renal glycosuria.
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This question is part of the following fields:
- Physiology
- Renal
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Question 3
Correct
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A 60-year-old woman has had persistent diarrhoea for a week. A stool test reveals an infection by Clostridium difficile. Which of the following antibiotics could be used to treat the infection?
Your Answer: Oral vancomycin
Explanation:Three antibiotics are effective against Clostridium difficile:
Metronidazole 500 mg orally three times daily is the drug of choice, because of superior tolerability, lower price and comparable efficacy.
Oral vancomycin 125 mg four times daily is second-line therapy in particular cases of relapse or where the infection is unresponsive to metronidazole treatment.
Thirdly, the use of linezolid might also be considered.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 4
Incorrect
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A 30 year old man suffered severe blood loss, approx. 20-30% of his blood volume. What changes are most likely seen in the pulmonary vascular resistance (PVR) and pulmonary artery pressure (PAP) respectively following this decrease in cardiac output?
Your Answer: Increase Increase
Correct Answer: Increase Decrease
Explanation:Hypovolemia will result in the activation of the sympathetic adrenal discharge resulting is a decrease pulmonary artery pressure and an elevated pulmonary vascular resistance.
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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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A 40 year old man from Japan was diagnosed with cancer of the oesophagus. He is to undergo esophagectomy. While mobilizing the oesophagus in the neck, for resection and anastomosis with the stomach tube on the left side, the surgeon must be cautious not to injure a vital structure. Which of the following is it?
Your Answer: Thoracic duct
Explanation:The oesophagus is divided into 3 portions: cervical (part that is in the neck), thoracic portion and the abdominal portion. The cervical part is bordered by the trachea anteriorly and the prevertebral fascia covering the bodies of the 6,7 and 8th vertebra posteriorly. The thoracic duct lies on the left side at the level of the sixth cervical vertebra. The carotid sheath with its contents and lower poles of the lateral lobes of thyroid gland are lateral. The thoracic duct is the structure most likely to be injured.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 6
Incorrect
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Medulloblastoma usually occurs in children between 5 to 9 years old. Where does medulloblastoma commonly originate from?
Your Answer: Cerebral hemispheres
Correct Answer: Cerebellar vermis
Explanation:Medulloblastoma is the most common malignant brain tumour in children, accounting for 10-20% of primary CNS neoplasms. Most of the tumours originate in the cerebellar vermis.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 7
Correct
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Which of the following toxins most likely results in continuous cAMP production, which pumps H2O, sodium, potassium, chloride and bicarbonate into the lumen of the small intestine and results in rapid dehydration?
Your Answer: Cholera toxin
Explanation:The cholera toxin (CTX or CT) is an oligomeric complex made up of six protein subunits: a single copy of the A subunit (part A), and five copies of the B subunit (part B), connected by a disulphide bond. The five B subunits form a five-membered ring that binds to GM1 gangliosides on the surface of the intestinal epithelium cells. The A1 portion of the A subunit is an enzyme that ADP-ribosylates G proteins, while the A2 chain fits into the central pore of the B subunit ring. Upon binding, the complex is taken into the cell via receptor-mediated endocytosis. Once inside the cell, the disulphide bond is reduced, and the A1 subunit is freed to bind with a human partner protein called ADP-ribosylation factor 6 (Arf6). Binding exposes its active site, allowing it to permanently ribosylate the Gs alpha subunit of the heterotrimeric G protein. This results in constitutive cAMP production, which in turn leads to secretion of H2O, Na+, K+, Cl−, and HCO3− into the lumen of the small intestine and rapid dehydration. The gene encoding the cholera toxin was introduced into V. cholerae by horizontal gene transfer.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 8
Incorrect
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When one is silently counting, what part of his brain will show increased regional cerebral blood flow (rCBF)?
Your Answer: Occipital cortex
Correct Answer: Supplementary motor area
Explanation:Regional cerebral blood flow (rCBF) increases in the superior speech cortex (supplementary motor area) during periods of silent counting, whereas speaking aloud will do so in the motor cortex and medial temporal lobe, along with the superior speech cortex.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 9
Correct
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The ability of the bacteria to cause disease or its virulence is related to :
Your Answer: Toxin and enzyme production
Explanation:The pathogenicity of an organism or its ability to cause disease is determined by its virulence factors. Many bacteria produce virulence factors that inhibit the host’s immune system. The virulence factors of bacteria are typically proteins or other molecules that are synthesized by enzymes. These proteins are coded for by genes in chromosomal DNA, bacteriophage DNA or plasmids. The proteins made by the bacteria can poison the host cells and cause tissue damage.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 10
Correct
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During a case presentation, a 26 year old is said to have fractured his pelvis and shattered his coccyx following a motorbike accident. It is mentioned that he is likely to have lacerated his middle sacral artery from this kind of injury. Where does the middle sacral artery branch from?
Your Answer: Abdominal aorta
Explanation:The middle sacral artery arises from behind the aorta a little above the point of its bifurcation to descend down in front of L4,5, the sacrum and coccyx.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 11
Correct
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A 60 year old patient with a history of carcinoma of the head of the pancreas, and obstructive jaundice presents with a spontaneous nose bleed and easy bruising. What is the most likely reason for this?
Your Answer: Vitamin-K-dependent clotting factors deficiency
Explanation:Vitamin K is a fat soluble vitamin requiring fat metabolism to function properly to allow for its absorption. People with obstructive jaundice develop vitamin k deficiency as fat digestion is impaired. Vit K causes carboxylation of glutamate residue and hence regulates blood coagulation including: prothrombin (factor II), factors VII, IX, X, protein C, protein S and protein Z.
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This question is part of the following fields:
- General
- Physiology
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Question 12
Incorrect
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Where is factor VIII predominantly synthesised?
Your Answer: Hepatocytes
Correct Answer: Vascular endothelium
Explanation:Factor VIII is an important part of the coagulation cascade. Deficiency causes haemophilia A. It is synthesised predominantly by the vascular endothelium and is not affected by liver disease. In the circulation it is bound to von Willebrand factor and it forms a stable complex with it. It is activated by thrombin or factor Xa and acts as a co factor to factor IXa to activate factor X which is a co factor to factor Va. Thrombin cleaves fibrinogen in fibrin and forms a meshwork to trap RBC and platelets to form a clot.
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This question is part of the following fields:
- General
- Physiology
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Question 13
Incorrect
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The primary motor cortex is located in the:
Your Answer: Postcentral gyrus
Correct Answer: Precentral gyrus
Explanation:The primary motor cortex is located in the dorsal part of the precentral gyrus and the anterior bank of the central sulcus. The precentral gyrus lies anterior to the postcentral gyrus and is separated from it by a central sulcus. Its anterior border is the precentral sulcus, while inferiorly it borders to the lateral fissure (Sylvian fissure).
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This question is part of the following fields:
- Neurology
- Physiology
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Question 14
Incorrect
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A 58-year-old woman diagnosed with deep vein thrombosis had been using warfarin for 10 days. When she presented to the doctor she had haemorrhagic bullae and necrotic lesions in her lower limbs and buttocks. Deficiency of which of the following proteins may have caused the necrotic skin lesions?
Your Answer: Protein Z
Correct Answer: Protein C
Explanation:Warfarin-induced skin necrosis is a rare complication of anticoagulant therapy that requires immediate drug cessation. The most common cutaneous findings include petechiae that progress to ecchymoses and haemorrhagic bullae. Warfarin inactivates vitamin K-dependent clotting factors II, VII, IX, and X and vitamin K-dependent proteins C and S. The concentration of protein C falls more rapidly than other vitamin K-dependent factors because they have a shorter half-lives. Skin necrosis is seen mainly in patients with prior protein C deficiency.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 15
Incorrect
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A 40-year old gentleman underwent a computed tomographic scan for the abdomen to rule out blunt abdominal trauma, after a vehicular accident. The scan revealed no abnormal finding except for a 1 cm-sized cortical mass in the left adrenal gland. The doctor-on-call decided to not intervene for this mass because it was likely to be a:
Your Answer: Adrenocortical carcinoma
Correct Answer: Non-functioning adrenal adenoma
Explanation:Adrenal adenomas are common, benign lesions which are asymptomatic and seen in 10% of population. Usually detected incidentally on Computed tomography (‘incidentaloma’), only around 1 in 10,000 are malignant (adenocarcinoma). Adrenal adenomas rarely need to be investigated, especially if they are homogenous and less than 3 cm in diameter. Follow-up imaging can be done after an interval of 3-6 months to assess any change in size. Some adenomas can secrete cortisol (leading to Cushing syndrome), or aldosterone (leads to Conn syndrome) or androgens (leading to hyperandrogenism).
Haematomas and simple cysts are not usually seen in adrenal gland. Infection due to Histoplasma capsulatum is usually bilateral and leads to multiple granulomas. Adrenal metastasis will usually demonstrate a lung primary and the adrenal lesions will be often multiple and larger than 1 cm.
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This question is part of the following fields:
- Endocrine
- Pathology
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Question 16
Incorrect
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Which of these foramen is located at the base of the skull and transmits the accessory meningeal artery?
Your Answer: Foramen magnum
Correct Answer: Foramen ovale
Explanation:At the base of the skull the foramen ovale is one of the larger of the several holes that transmit nerves through the skull. The following structures pass through foramen ovale: mandibular nerve, motor root of the trigeminal nerve, accessory meningeal artery, lesser petrosal nerve, a branch of the glossopharyngeal nerve, emissary vein connecting the cavernous sinus with the pterygoid plexus of veins and occasionally the anterior trunk of the middle meningeal vein.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 17
Incorrect
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In the emergency room, a nurse was introducing a catheter into the patients femoral vein for rapid fluid therapy. The femoral vein is situated inside the femoral sheath. Which of the following is true about that sheath?
Your Answer: The lateral compartment of the femoral sheath contains the femoral vein
Correct Answer: The medial compartment is called the femoral canal
Explanation:The femoral sheath is situated ,4cm below the inguinal ligament. It is a prolongation of the abdominal fascia. The anterior wall is a prolongation of the transversalis fascia and the posterior wall, the iliac fascia. It is divided by two vertical septa into 3 compartments, lateral, intermediate, and medial. The medial compartment is known as the femoral canal and contains some lymphatic vessels. The lateral one contains the femoral artery and the intermediate one contains the femoral vein.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 18
Incorrect
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A 44-year old man, who was euthyroid underwent thyroidectomy following neoplastic cells found on fine-needle aspiration. Frozen section of multiple thyroid masses showed malignant neoplasm of polygonal cells in nests. The neoplasm also showed presence of amyloid which was positive with Congo-red staining. Immunoperoxidase staining for calcitonin was also positive. Chest X-ray revealed no abnormality. However, his blood pressure was found to be raised, and his serum ionised calcium was high. What is the likely diagnosis?
Your Answer: Multiple endocrine neoplasia type IIB
Correct Answer: Multiple endocrine neoplasia type IIA
Explanation:MEN (Multiple Endocrine Neoplasia) syndromes are a group of three separate familial disease which consists of adenomatous hyperplasia and neoplasia in several endocrine glands. All three conditions are inherited as an autosomal dominant trait, with a single gene producing multiple effects. MEN IIA is characterized by medullary carcinoma of the thyroid, pheochromocytoma and hyperparathyroidism. It should be suspected in patients with bilateral pheochromocytoma, a familial history of MEN, or at least two characteristic endocrine manifestations. Genetic testing is used to confirm the diagnosis. Early diagnosis is crucial to aid in complete excision of the localized tumour. Pheochromocytomas can be detected by plasma free metanephrines and fractionated urinary catecholamines, particularly adrenaline (epinephrine).
Imaging studies such as computed tomography or magnetic resonance imaging might also prove useful. Hyperparathyroidism is diagnosed by the standard finding of hypercalcaemia, hypophosphatemia and an increased parathyroid hormone level. Once MEN IIA syndrome is identified in any patient, it is recommended that his or her first-degree relatives and any other symptomatic also undergo genetic testing. Relatives should be subjected to annual screening for hyperparathyroidism and pheochromocytoma beginning in early childhood and continue indefinitely. Serum calcium levels help in screening for hyperparathyroidism. Similarly, screening for pheochromocytoma is by history, measurement of the blood pressure and laboratory testing.
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This question is part of the following fields:
- Endocrine
- Pathology
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Question 19
Correct
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A chest X-ray in a healthy, non-smoker, asymptomatic 48-year-old woman reveals a 2cm left lower lobe well-defined round opacity. Which of the following conditions is most probably responsible for this finding?
Your Answer: Pulmonary hamartoma
Explanation:An asymptomatic healthy patient with no history of smoking and a lesion of small size most probably has a benign lung lesion. Hamartomas are one of the most common benign tumours of the lung that accounts for approximately 6% of all solitary pulmonary nodules. Pulmonary hamartomas are usually asymptomatic and therefore are found incidentally when performing an imaging test for other reasons.
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This question is part of the following fields:
- Pathology
- Respiratory
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Question 20
Correct
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A 14-year old girl presented with a 2cm, mobile, cystic mass in the midline of her neck. Fine needle aspiration of the mass revealed clear fluid. This is most likely a case of:
Your Answer: Thyroglossal duct cyst
Explanation:Thyroglossal cyst is the most common congenital thyroid anomaly which is clinically significant and affects women more than men. It is a vestigial remnant of developing thyroid. Although the thyroglossal cyst can develop anywhere along the thyroglossal duct, the most common site is in the midline between the isthmus of thyroid and hyoid bone, or just above the hyoid. Thyroglossal cysts are also associated with ectopic thyroid tissue. Clinically, the cyst moves upward with protrusion of the tongue. Rarely, the persistent duct can become malignant (thyroglossal duct carcinoma) where the cancerous cells arise in the ectopic thyroid tissue that are deposited along the duct. Exposure to radiation is a predisposing factor.
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This question is part of the following fields:
- Endocrine
- Pathology
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Question 21
Correct
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Carbon dioxide is principally transported in the blood in which form?
Your Answer: Bicarbonate
Explanation:Carbon dioxide is transported in the blood in various forms:
– Bicarbonate (80–90%)
– Carbamino compounds (5–10%)
– Physically dissolved in solution (5%).
Carbon dioxide is carried on the haemoglobin molecule as carbamino-haemoglobin; carboxyhaemoglobin is the combination of haemoglobin with carbon monoxide.
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This question is part of the following fields:
- Physiology
- Respiratory; Cardiovascular
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Question 22
Incorrect
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A TRUE statement regarding abolition of the cephalic phase of pancreatic secretion is that it:
Your Answer: Is not possible
Correct Answer: Will result after vagotomy
Explanation:Recognition and integration of the sight, smell and taste of food triggers the cephalic phase of pancreatic secretion, causing an increase in pancreatic HCO3- and enzyme secretion. The degree of enzyme secretion in this phase is about 50% of the maximal response seen with exogenous CCK and secretin. The vagus nerve regulates the secretion through the cholinergic fibres innervating the acinar cells of the pancreas, and through peptidergic nerve fibres, which innervate ductal cells.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 23
Correct
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A 50-year-old man is diagnosed with emphysema and cirrhosis of the liver. Which of the following condition may be the cause of both cirrhosis and emphysema in this patient?
Your Answer: Alpha1-antitrypsin deficiency
Explanation:Alpha-1 antitrypsin (A1AT) deficiency is a condition characterised by the lack of a protein that protects the lungs and liver from damage, called alpha1-antytripsin. The main complications of this condition are liver diseases such as cirrhosis and chronic hepatitis, due to accumulation of abnormal alpha 1-antytripsin and emphysema due to loss of the proteolytic protection of the lungs.
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This question is part of the following fields:
- Pathology
- Respiratory
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Question 24
Correct
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Choose the most correct answer regarding the obturator internus muscle.
Your Answer: It emerges from the pelvis through the lesser sciatic foramen
Explanation:The obturator internus arises from the inner surface of the anterolateral wall of the pelvis and the pelvic surface of the obturator membrane. The fibres converge rapidly towards the lesser sciatic foramen and end in four or five tendinous bands and leave the pelvis through the lesser sciatic foramen.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 25
Correct
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A 5-year-old child diagnosed with nephrotic syndrome developed generalised oedema. What is the mechanism for the development of oedema in patients with nephrotic syndrome?
Your Answer: Decreased colloid osmotic pressure
Explanation:The development of oedema in nephrotic syndrome has traditionally been viewed as an underfill mechanism. According to this view, urinary loss of protein results in hypoalbuminemia and decreased plasma oncotic pressure. As a result, plasma water translocates out of the intravascular space and results in a decrease in intravascular volume. In response to the underfilled circulation, effector mechanisms are then activated that signal the kidney to secondarily retain salt and water. While an underfill mechanism may be responsible for oedema formation in a minority of patients, recent clinical and experimental findings would suggest that oedema formation in most nephrotic patients is the result of primary salt retention. Direct measurements of blood and plasma volume or measurement of neurohumoral markers that indirectly reflect effective circulatory volume are mostly consistent with either euvolemia or a volume expanded state. The ability to maintain plasma volume in the setting of a decreased plasma oncotic pressure is achieved by alterations in transcapillary exchange mechanisms known to occur in the setting of hypoalbuminemia that limit excessive capillary fluid filtration.
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This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
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Question 26
Correct
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A 40-year old gentleman, known with a history of peptic ulcer disease, was brought to the clinic in a dehydrated state with persistent vomiting. His blood investigations revealed:
- sodium = 142 mmol/l
- potassium = 2.6 mmol/l
- chloride = 85 mmol/l
- pH = 7.55
- p(CO2) = 50 mmHg
- p(O2) = 107 mmHg
- standard bicarbonate = 40 mmol/l
Your Answer: Metabolic alkalosis
Explanation:High pH with high standard bicarbonate indicates metabolic alkalosis. The pa(CO2) was appropriately low in compensation. This is hypokalaemic hypochloraemic metabolic acidosis due to prolonged vomiting. Treatment includes treating the cause and intravenous sodium chloride with potassium.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 27
Incorrect
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Which of the following coagulation factors cross-links fibrin?
Your Answer: Factor X
Correct Answer: Factor XIII
Explanation:Factor XIII, also known as fibrin stabilizing factor, is an enzyme of the coagulation cascade that crosslinks fibrin. Deficiency of FXIII may cause bleeding tendency but paradoxically, it may also predispose to thrombosis.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 28
Correct
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A 20 year old is brought to the A&E after he fell from a moving cart. The boy has sustained blunt abdominal injury, and the there is a possibility of internal bleeding as the boy is in shock. An urgent exploratory laparotomy is done in the A&E theatre. On opening the peritoneal cavity, the operating surgeon notices a torn gastrosplenic ligament with a large clot around the spleen. Which artery is most likely to have been injured in this case?
Your Answer: Short gastric
Explanation:The short gastric arteries branch from the splenic artery near the splenic hilum to travel back in the gastrosplenic ligament to supply the fundus of the stomach. Therefore, these may be injured in this case.
The splenic artery courses deep to the stomach to reach the hilum of the spleen. It doesn’t travel in the gastrosplenic ligament although it does give off branches that do.
The middle colic artery is a branch of the superior mesenteric artery that supplies the transverse colon.
Gastroepiploic artery is the largest branch of the splenic artery that courses between the layers of the greater omentum to anastomose with the right gastroepiploic.
Left gastric artery, a branch of the coeliac trunk. It supplies the left half of the lesser curvature.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 29
Correct
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Which is the correct superficial to deep order of structures that would be affected following a knife wound to the lateral aspect of the knee?
Your Answer: skin, fibular collateral ligament, popliteus muscle tendon, lateral meniscus
Explanation:Skin, fibular collateral ligament, popliteus muscle tendon and lateral meniscus is the correct order of structures covering the lateral aspect of the knee joint from a superficial to deep.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 30
Correct
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Post-total gastrectomy, there will be a decreased production of which of the following enzymes?
Your Answer: Pepsin
Explanation:Pepsin is a protease that is released from the gastric chief cells and acts to degrade proteins into peptides. Released as pepsinogen, it is activated by hydrochloric acid and into pepsin itself. Gastrin and the vagus nerve trigger the release of pepsinogen and HCl when a meal is ingested. Pepsin functions optimally in an acidic environment, especially at a pH of 2.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 31
Correct
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Macrolides are a group of antibiotics commonly used to treat respiratory tract and soft-tissue infections. Which of the following antibiotics is a macrolide?
Your Answer: Erythromycin
Explanation:Erythromycin is a macrolide antibiotic used in the treatment of several bacterial infections, including respiratory tract infections, skin infections, chlamydia infections, pelvic inflammatory disease, and syphilis. It may also be used during pregnancy to prevent Group B streptococcal infection in the new-born.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 32
Correct
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The posterior cord contains nerve fibres from which of the following levels of the spinal cord?
Your Answer: C5, C6, C7, C8 and T1
Explanation:THE correct answer is A. The posterior cord derives its fibres from the spinal nerves C5,C6,C7,C8,T1. This cord is formed from the fusion of the posterior divisions of the upper, lower, and middle trunks.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 33
Correct
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An amateur body-builder complains of increasing pain in his right shoulder after a few days of intense training. A surgeon aspirates clear fluid from his subdeltoid region. What's the most likely diagnosis?
Your Answer: Bursitis
Explanation:Bursae are potential cavities that contain synovial fluid, found in areas where friction occurs. Their function is to minimise friction and facilitate movement. Bursitis is the inflammation of one or more bursae, and they can occur in the shoulder, elbow, knee, ischium, amongst other joints. Acute bursitis can appear after strenuous exercise or activity, and chronic bursitis can develop following previous bursitis or trauma. Acute bursitis causes pain, tenderness, and swelling.
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This question is part of the following fields:
- Orthopaedics
- Pathology
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Question 34
Correct
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The stomach is an organ that is divided into several important anatomical parts. These parts of the stomach have varied arterial blood supply that ensure that the whole organ receive oxygenated blood. Which of the following arteries if ligated, will not render any portion of the stomach ischaemic?
Your Answer: Superior mesenteric
Explanation:The blood supply to the stomach is through the following arteries:
– The superior mesenteric artery supplies blood to the lower part of the duodenum, pancreas and two-thirds of the transverse colon. Thus ligation of the superior mesenteric artery would not affect the stomach.
– The right and the left gastroepiploic arteries supply the greater curvature of the stomach – along its edges.
– The short gastric artery supplies blood to the upper portion of the of the greater curvature and the fundus of the stomach.
– The gastroduodenal artery supplies blood to the distal part of the stomach (the pyloric sphincter) and the proximal end of the duodenum.
– The left gastroepiploic and the short gastric are branches of the splenic artery and therefore ligation of the splenic artery would directly affect the stomach.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 35
Correct
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One sensitive indicator of heavy alcohol dependence is:
Your Answer: Elevated serum gamma-glutamyl transpeptidase
Explanation:Elevated serum gamma-glutamyl transpeptidase (GGT) may be the only laboratory abnormality in patients who are dependent on alcohol. Heavy drinkers may also have an increased MCV.
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This question is part of the following fields:
- Hepatobiliary
- Physiology
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Question 36
Correct
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The nutcracker effect of the alimentary canal is described as a nutcracker-like compression caused by the aorta and the superior mesenteric arteries on a certain section of the alimentary canal leading to bowel obstruction. Which of the following parts of the alimentary canal is usually obstructed by this nutcracker compression of the two arteries?
Your Answer: Duodenum
Explanation:The ‘nutcracker effect’ is only seen in one part of the alimentary canal, and that is in the third part of the duodenum. This can happen when the superior mesenteric artery that passes across the duodenum and the aorta, posteriorly to the third part of the duodenum enlarges and starts compressing the duodenum. The result is an obstructed duodenum that inhibits passage of food.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 37
Correct
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A chloride sweat test was performed on a 13-year-old boy. Results indicated a high likelihood of cystic fibrosis. This diagnosis is associated with a higher risk of developing which of the following?
Your Answer: Bronchiectasis
Explanation:Cystic fibrosis is a life-threatening disorder that causes the build up of thick mucus in the lungs, digestive tract, and other areas of the body. It is a hereditary autosomal-recessive disease caused by mutations of the CFTR gene. Cystic fibrosis eventually results in bronchiectasis which is defined as a permanent dilatation and obstruction of bronchi or bronchioles.
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This question is part of the following fields:
- Pathology
- Respiratory
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Question 38
Incorrect
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A 27 year old women works in a dry-cleaning shop. She was exposed to massive amounts of carbon tetrachloride on her skin as well as inhaled. Which of the following organs is most susceptible to damage?
Your Answer: Heart
Correct Answer: Liver
Explanation:Carbon tetrachloride (CCl4) is a common agent used in the dry cleaning industry and is thought to cause the formation of free radicals. It causes rapid breakdown of the endoplasmic reticulum due to decomposition of lipids and severe liver cell injury. Within less than 30 mins, hepatic protein synthesis declines, lipid export is reduced due to lack of apoprotein and there is an influx of calcium and cell death.
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This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
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Question 39
Incorrect
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Injury to the supraspinatus muscle will affect:
Your Answer: Abduction of the humerus above the horizontal plane
Correct Answer: Initiation of abduction of the humerus
Explanation:This muscle arises from the medial two-thirds of the supraspinatus fossa and from the supraspinatus fascia. It is inserted into the highest impression on the greater tubercle of the humerus after passing over the upper part of the shoulder joint. It works with the deltoid to raise the arm from the side of the trunk and initiate abduction. It also assists in fixation of the head of the humerus in the glenoid cavity.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 40
Correct
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Which of the following over-the-counter drugs can cause a prolonged bleeding time?
Your Answer: Acetylsalicylic acid
Explanation:Acetylsalicylic acid, or aspirin, is a nonsteroidal anti-inflammatory drug that is widely used as an analgesic and antipyretic. Aspirin is as a cyclo-oxygenase inhibitor that leads to decreased prostaglandin production. Decreased platelet aggregation is another effect of this drug, achieved by long-lasting use of aspirin.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 41
Correct
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A 25 year old man presented with a history of headache and peripheral cyanosis. He had been living in the Himalayas for 6 months prior to this. What is the reason for his condition?
Your Answer: Physiological polycythaemia
Explanation:Polycythaemia is a condition that results in an increase in the total number of red blood cells (RBCs) in the blood. It can be due to myeloproliferative syndrome or due to chronically low oxygen levels or rarely malignancy. In primary polycythaemia/polycythaemia vera the increase is due to an abnormality in the bone marrow, resulting in increases RBCs, white blood cells (WBCs) and platelets. In secondary polycythaemia the increase occurs due to high levels of erythropoietin either artificially or naturally. The increase is about 6-8 million/cm3 of blood. A type of secondary polycythaemia is physiological polycythaemia where people living in high altitudes who are exposed to hypoxic conditions produce more erythropoietin as a compensatory mechanism for thin oxygen and low oxygen partial pressure.
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This question is part of the following fields:
- General
- Physiology
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Question 42
Incorrect
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A 65-year old gentleman presents to the clinic with chronic back pain and weight loss. His blood count shows a white blood cell count of 10 × 109/l, with a differential count of 66 polymorphonuclear leukocytes, 7 bands, 3 metamyelocytes, 3 myelocytes, 14 lymphocytes, 7 monocytes, and 5 nucleated red blood cells. The haemoglobin is 13 g/dl with a haematocrit of 38.1%, a mean corpuscular volume of 82 fl, and a platelet count of 126 × 109/l. What is the likely diagnosis?
Your Answer: Chronic lymphocytic leukaemia
Correct Answer: Metastatic carcinoma
Explanation:The peripheral blood findings suggest a leucoerythroblastic picture, the common causes of which in a 65-year old gentleman includes prostatic or lung malignancy.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 43
Incorrect
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During pregnancy the uterus enlarges however after delivery it regresses to its original size. Which of the following organelles is responsible for this regression?
Your Answer: Centrioles
Correct Answer: Lysosomes
Explanation:Lysosomes are formed by budding of the Golgi apparatus and contain enzymes which digest macromolecules. They are found in both plants and animals and are active in autophagic cell death, digestion after phagocytosis and for the cells own recycling process. They fuse with the molecules and release their content resulting in digestion.
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This question is part of the following fields:
- General
- Physiology
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Question 44
Correct
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Which muscle in the neck divides the neck into two large triangles?
Your Answer: Sternocleidomastoid
Explanation:The sternocleidomastoid muscle is an important landmark in the neck as it divides the neck into two; anterior and posterior triangles. These triangles help in the location of the structures of the neck including the carotid artery, head and neck lymph nodes, accessory nerve and the brachial plexus. It originates from the manubrium and medial portion of the clavicle and inserts on the mastoid process of the temporal bone, superior nuchal line. The sternocleidomastoid receives blood supply from the occipital artery and the superior thyroid artery. It is innervated by the accessory nerve (motor) and cervical plexus (sensory).
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 45
Incorrect
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Intravenous diazepam was administered to a man who was brought to the emergency department with status epilepticus. He was administered 15 l/min oxygen via a reservoir bag mask. Blood investigations showed sodium = 140 mmol/l, potassium = 4 mmol/l and chloride = 98 mmol/l. His arterial blood gas analysis revealed pH 7.08, p(CO2)= 61.5 mmHg, p(O2) = 111 mmHg and standard bicarbonate = 17 mmol/l. This patient had:
Your Answer: Respiratory acidosis
Correct Answer: Mixed acidosis
Explanation:Acidosis with high p(CO2) and low standard bicarbonate indicates mixed acidosis. Lower p(O2) is due to breathing of 70% oxygen. The prolonged seizures lead to lactic acidosis and the intravenous diazepam is responsible for the respiratory acidosis. Treatment includes airway manoeuvres and oxygen, assisted ventilation if needed, and treatment with fluids.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 46
Correct
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A suspected recreational drug user was brought to the Emergency department in an unconscious state, and was found to be hypoventilating. Which of the following set of arterial blood gas analysis report is most consistent with hypoventilation as the primary cause? pH, pa(CO2) (mmHg), pa(O2) (mmHg).
Your Answer: 7.28, 55, 81
Explanation:Hypoventilation (or respiratory depression) causes an increase in carbon dioxide (hypercapnia) and respiratory acidosis. It can result due to drugs such as alcohol, benzodiazepines, barbiturates, opiates, mechanical conditions or holding ones breath. Strong opioids such as heroin and fentanyl are commonly implicated and can lead to respiratory arrest. In recreational drug overdose, acute respiratory acidosis occurs with an increase in p(CO2) over 45 mm Hg and acidaemia (pH < 7.35)
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 47
Correct
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A 12-year old girl was brought to the hospital with recurrent headaches for 6 months. Her physical examination revealed no abnormality. A CT scan of the head revealed a suprasellar mass with calcifications, eroding the surrounding sella turcica. The lesion is likely to represent:
Your Answer: Craniopharyngioma
Explanation:Craniopharyngiomas (also known as Rathke pouch tumours, adamantinomas or hypophyseal duct tumours) affect children mainly between the age of 5 and 10 years. It constitutes 9% of brain tumours affecting the paediatric population. These are slow-growing tumours which can also be cystic, and arise from the pituitary stalk, specifically the nests of epithelium derived from Rathke’s pouch. Histologically, this tumour shows nests of squamous epithelium which is lined on the outside by radially arranged cells. Calcium deposition is often seen with a papillary type of architecture.
ACTH-secreting pituitary adenomas are rare and mostly microadenomas. Paediatric astrocytoma’s usually occur in the posterior fossa. Although null cell adenomas can cause mass effect and give rise to the described symptoms, they are not suprasellar. Prolactinomas can also show symptoms of headache and disturbances in the visual field, however they are known to be small and slow-growing.
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This question is part of the following fields:
- Endocrine
- Pathology
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Question 48
Incorrect
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A 27 year old women had developed a darker complexion following a vacation to India. She had no erythema or tenderness. Her skin colour returned to normal over a period of 1 month. Which of the these substances is related to the biochemical change mentioned above?
Your Answer: Hemosiderin
Correct Answer: Tyrosine
Explanation:The tanning process can occur due to UV light exposure as a result of oxidation of tyrosine to dihydrophenylalanine with the help of the tyrosinase enzyme within the melanocytes. Hemosiderin can impart a brown colour due to breakdown of RBC but its usually due to a trauma and is known as haemochromatosis.
Lipofuscin gives a golden brown colour to the cell granules not the skin.
Homogentisic acid is part of a rare disease alkaptonuria, with characteristic black pigment deposition within the connective tissue.
Copper can impart a brown golden colour, but is not related to UV light exposure.
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This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
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Question 49
Correct
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Following a lacerating injury along the anterior border of the trapezius muscle in the neck, a man has the point of his shoulder (scapula) sagging and he has difficulty with full abduction of his arm. Which nerve is most likely injured?
Your Answer: Accessory (cranial nerve XI)
Explanation:Injury to the accessory nerve denervates the trapezius muscle so that the person will no longer be able to raise the acromion of the shoulder. The dorsal scapular nerve supplies the rhomboids i.e. major and minor and the levator scapulae so that injury to this nerve weakens retraction of the scapula. The greater occipital nerve is responsible for sensation of the posterior scalp. The axillary nerve innervates the deltoid muscle which is responsible for abduction of the arm and the suprascapular nerve is responsible for rotating the humerus laterally. Cutaneous nerves supply the skin.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 50
Correct
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Ventricular filling follows a delay caused by?
Your Answer: AV node
Explanation:The AV node is a conducting tissue found between the atria and the ventricles of the heart. It conducts electrical signal from the atria to the ventricles and acts a delaying mechanism preventing the atria and the ventricles from contracting at the same time. This decremental conduction prevents premature ventricular contraction in cases such as atrial fibrillation. A delay in the AV node is the reason for the PR segment seen on the ECG. In certain types of supraventricular tachycardia, a person could have two AV nodes; this will cause a loop in electrical current and uncontrollably rapid heart beat. When this electricity catches up with itself, it will dissipate and return to a normal heart rate.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 51
Correct
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Purkinje fibres in the heart conduct action potentials at the rate of:
Your Answer: 1.5–4.0 m/s
Explanation:Purkinje fibres control the heart rate along with the sinoatrial node (SA node) and the atrioventricular node (AV node). The QRS complex is associated with the impulse passing through the Purkinje fibres. These fibres conduct action potential about six times faster than the velocity in normal cardiac muscle.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 52
Incorrect
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Which of these nerves controls adduction of hand?
Your Answer: Median nerve
Correct Answer: Ulnar nerve
Explanation:The adductors of the fingers are the palmer interossei. They are supplied by the ulnar nerve, which is a branch of the medical cord of the brachial plexus.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 53
Correct
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Which of the following substances is most likely to cause pulmonary vasodilatation?
Your Answer: Nitric oxide
Explanation:In the body, nitric oxide is synthesised from arginine and oxygen by various nitric oxide synthase (NOS) enzymes and by sequential reduction of inorganic nitrate. The endothelium of blood vessels uses nitric oxide to signal the surrounding smooth muscle to relax, so dilating the artery and increasing blood flow. Nitric oxide/oxygen blends are used in critical care to promote capillary and pulmonary dilation to treat primary pulmonary hypertension in neonatal patients post-meconium aspiration and related to birth defects.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 54
Correct
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When a patient that is less than 21 years of age develops a bone tumour. What is the most common benign bone tumour that would be considered in individuals below 21 years?
Your Answer: Osteochondroma
Explanation:Osteochondroma is a benign new bone growth that protrudes from the outer contour of bones and is capped by growing cartilage. Nearly 80% of these lesions are noted before the age of 21 years.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 55
Correct
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A 32-year-old man presents to the doctor complaining of pain in his left calf whilst walking. He says that the pain goes away after a short period of rest but starts again during exercise or walking. The man reveals he has been a smoker for the last 15 years. His blood pressure, blood sugar and cholesterol level are normal. Artery biopsy shows intraluminal thrombosis and vasculitis. What's is the most likely cause of these findings?
Your Answer: Buerger's disease
Explanation:Thromboangiitis obliterans, also known as Buerger’s disease, is a rare type of occlusive peripheral arterial disease, usually seen in smokers, most commonly in men aged 20 to 40. Symptoms most often include intermittent claudication, skin changes, painful ulcers on extremities, pain in the extremities during rest and gangrene. Diagnosis is based on clinical findings, arteriography, echocardiography, and computed tomography angiography. A difference in blood pressure between arms, or between the arms and legs is a common finding. Electrocardiographic findings include nonspecific abnormality or normal results.
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This question is part of the following fields:
- Cardiovascular
- Pathology
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Question 56
Incorrect
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The transmembrane proteins responsible for resting membrane potential of vascular smooth muscle cells was blocked by a drug. Which of the following transmembrane proteins were blocked by this drug?
Your Answer: Ca2+ channels
Correct Answer: K+ channels
Explanation:The resting membrane potential is due to selective permeability of the membrane to potassium ions. The Na/K pump is responsible for the generation of a gradient across the membrane and it is due to the inherent ability of the K channels to allow diffusion back into the nerve at rest which charges the cells. In reality, the resting membrane potential is more positive because of small contributions by Na+ channels, Cl− channels and non-selective cation channels.
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This question is part of the following fields:
- General
- Physiology
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Question 57
Incorrect
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Which of the following tumours has the best prognosis following surgery?
Your Answer: Medulloblastoma
Correct Answer: Schwannoma
Explanation:Schwannomas are histologically benign neoplasms that arise from nerve sheaths, most commonly from sensory nerve roots. They are generally contained within a capsule, and so can be surgically removed without injuring the associated nerve root. They are histologically benign and less than 1% become malignant.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 58
Correct
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What class of drugs does buspirone belong to?
Your Answer: Anxiolytic
Explanation:Buspirone is an anxiolytic agent and a serotonin-receptor agonist that belongs to the azaspirodecanedione class of compounds. It shows no potential for addiction compared with other drugs commonly prescribed for anxiety, especially the benzodiazepines. The development of tolerance has not been noted. It is primarily used to treat generalized anxiety disorders. It is also commonly used to augment antidepressants in the treatment of major depressive disorder.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 59
Correct
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A 40-year old woman with portal hypertension has impaired venous drainage of the anal canal above the pectinate line. Thus, there might be an increase in blood flow downward to the systemic venous system via anastomoses with the inferior rectal vein. This is a tributary of?
Your Answer: Internal pudendal vein
Explanation:The inferior rectal vein drains into the internal pudendal vein. In addition the external iliac vein is one of the two branches of the common iliac vein however the internal iliac vein and it’s tributaries (including the pudendal vein) are much more important in draining the pelvic structures.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 60
Incorrect
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A 55-year-old male has a mass on the right lung with involvement of the right mediastinal lymph nodes. What is the nodal staging according to the TNM staging?
Your Answer: N3
Correct Answer: N2
Explanation:The N stages for lung cancer are from NO to N3 : NO, there is no lung cancer in any lymph nodes: N1, there is lung cancer in the proximal lymph nodes: N2, there is lung cancer in the mediastinal hilar lymph nodes, but on the same side as the affected lung or there is lung cancer in the carinal lymph nodes: N3, there is metastatic lung cancer in lymph nodes on the opposite side of the chest, in the cervical or apical lymph nodes. In this patient the ipsilateral mediastinal node is involved, thus it is classified as N2.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 61
Correct
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A patient is diagnosed with lung cancer. His physician told him that his lung cancer type is aggressive. It can grow rapidly and may undergo early metastasis, however it is very sensitive to chemotherapy and radiotherapy. Which lung cancer type is most likely present
Your Answer: Small-cell carcinoma
Explanation:Small-cell lung carcinoma (SCLC) is a type of highly malignant cancer that most commonly arises within the lung. SCLC usually metastasizes widely very early on in the natural history of the tumour, and in nearly all cases responds dramatically to chemotherapy and/or radiotherapy. Surgery has no role in the treatment of this disease.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 62
Correct
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Which structure holds the duodenojejunal flexure in place?
Your Answer: Suspensory ligament (of Treitz)
Explanation:The duodenum is connected to the diaphragm by the suspensory ligament called the ligament of Treitz. It is a slip of skeletal muscle from the right crus of the diaphragm and a fibromuscular band of smooth muscle from the 3rd and 4th parts of the duodenum. It is an important landmark, used to divide the gastrointestinal tract into the upper and lower parts. Contraction of this ‘ligament’ leads to opening of the duodenojejunal flexure allowing the flow of chyme.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 63
Correct
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Which of the following will be a likely sequelae of complete ileal resection?
Your Answer: Vitamin B12 deficiency
Explanation:The ileum is a part of the small intestine and has a pH of around 7-8 (neutral or slightly alkaline). Its main function is absorption of products of digestion. The ileal wall has multiple villi, which in turn have numerous microvilli. This increases the surface area available for absorption significantly. The cells lining the ileum contain multiple enzymes such as protease and carbohydrase, which aid in the final stages of digestion. Villi contain lacteals which absorb the products of fat digestion, fatty acids and glycerol. Thus, ileal resection will lead to their decreased absorption and increased fat content in the stool. The ileum is also responsible for absorption of vitamin B12.
Maximum water absorption occurs in the colon followed by the jejunum. Hence, ileal resection is less likely to lead to fluid volume deficiency. Also, most minerals (like calcium, iron etc.) are absorbed in the duodenum, and thus will not be affected by ileal resection.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 64
Incorrect
-
The Henderson–Hasselbalch equation describes the derivation of pH as a measure of acidity. According to this equation, the buffering capacity of the system is at maximum when the number of free anions compared with undissociated acid is:
Your Answer: Exactly half
Correct Answer: Equal
Explanation:In 1908, Lawrence Joseph Henderson wrote an equation describing the use of carbonic acid as a buffer solution. Later, Karl Albert Hasselbalch re-expressed that formula in logarithmic terms, resulting in the Henderson–Hasselbalch equation. The equation is also useful for estimating the pH of a buffer solution and finding the equilibrium pH in acid–base reactions. Two equivalent forms of the equation are: pH = pKa + log10 [A–]/[HA] or pH = pKa + log10 [base]/[acid]. Here, pKa is − log10(Ka) where Ka is the acid dissociation constant, that is: pKa = –log10(Ka) = –log10 ([H3 O+][A–]/[HA]) for the reaction: HA + H2 O ≈ A– + H3 O+ In these equations, A– denotes the ionic form of the relevant acid. Bracketed quantities such as [base] and [acid] denote the molar concentration of the quantity enclosed. Maximum buffering capacity is found when pH = pKa or when the number of free anions to undissociated acid is equal and buffer range is considered to be at a pH = pKa ± 1.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 65
Incorrect
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Blood supply to the posterior compartment of the thigh is supplied by which artery?
Your Answer: Obturator
Correct Answer: Perforating
Explanation:There are usually 3 perforating arteries:
The first gives branches to the adductor brevis and magnus, biceps femoris and gluteus maximus and anastomoses with the inferior gluteal, medial and lateral femoral circumflex.
The second artery supplies the posterior femoral muscles and anastomose with the first and third perforating vessels.
The third supplies the posterior femoral muscles.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 66
Incorrect
-
An abdominal aortogram shows occlusion of the inferior mesenteric artery. Which of the following segments of bowel is most likely to have preserved arterial supply?
Your Answer: Splenic flexure
Correct Answer: Caecum
Explanation:The inferior mesenteric artery supplies blood to the end of the transverse colon and all distal structures in the gastrointestinal tract i.e. splenic flexure, descending colon, sigmoid colon and rectum would all be deprived of blood if it were occluded. The caecum receives blood from the superior mesenteric artery so it would not be affected.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 67
Incorrect
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Which of the following arteries, that runs on the superior aspect of the first part of the duodenum, forms the lower boundary of the epiploic foramen (also known as the foramen of Winslow)?
Your Answer: Superior pancreaticoduodenal
Correct Answer: Hepatic
Explanation:The epiploic foramen is an important anatomical opening that allows for the communication between the greater peritoneal sac and the lesser peritoneal sac. Its boundaries are formed; superiorly by the caudate lobe of the liver, anteriorly by the hepatoduodenal ligament (containing the components of the portal triad), inferiorly by the first part of the duodenum and posteriorly by the peritoneum covering the inferior vena cava. The superior aspect of the first part of the duodenum, which forms the inferior boundary of the foramen of Winslow, forms the course of the hepatic artery before it ascends to the porta hepatis where it divides into its right and left branches.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 68
Incorrect
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Calculate the cardiac output of a patient with the following measurements: oxygen uptake 200 ml/min, oxygen concentration in the peripheral vein 7 vol%, oxygen concentration in the pulmonary artery 10 vol% and oxygen concentration in the aorta 15 vol%.
Your Answer: 3500 ml/min
Correct Answer: 4000 ml/min
Explanation:The Fick’s principle states that the uptake of a substance by an organ equals the arteriovenous difference of the substance multiplied by the blood flowing through the organ. We can thus calculate the pulmonary blood flow with pulmonary arterial (i.e., mixed venous) oxygen content, aortic oxygen content and oxygen uptake. The pulmonary blood flow, systemic blood flow and cardiac output can be considered the same assuming there are no intracardiac shunts. Thus, we can calculate the cardiac output. Cardiac output = oxygen uptake/(aortic − mixed venous oxygen content) = 200 ml/min/(15 ml O2/100 ml − 10 ml O2/100 ml) = 200 ml/min/(5 ml O2/100 ml) = 200 ml/min/0.05 = 4000 ml/min.
It is crucial to remember to use pulmonary arterial oxygen content and not peripheral vein oxygen content, when calculating the cardiac output by Fick’s method.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 69
Correct
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A young man came to the emergency room after an accident. The anterior surface of his wrist was lacerated with loss of sensation over the thumb side of his palm. Which nerves have been damaged?
Your Answer: Median
Explanation:The median nerve provides cutaneous innervation to the skin of the palmar radial three and a half fingers. Also the site of injury indicates that the medial nerve may have been injured as it passes into the hand by crossing over the anterior wrist.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 70
Correct
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A gymnast was admitted to hospital for investigation of a weakness in the extension and adduction of his arm. He had a previous penetrating wound in the area of the posterior axillary fold. Which of these muscles is the likely cause?
Your Answer: Latissimus dorsi
Explanation:All the criteria of this case points towards the latissimus dorsi. This muscle is greatly involved in extension, adduction and medial rotation of the arm and forms the posterior axillary fold which in this case was injured.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 71
Incorrect
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Which of the following is the cause of flattened (notched) T waves on electrocardiogram (ECG)?
Your Answer: Hypocalcaemia
Correct Answer: Hypokalaemia
Explanation:The T-wave is formed due to ventricular repolarisation. Normally, it is seen as a positive wave. It can be normally inverted (negative) in V1 (occasionally in V2-3 in African-Americans/Afro-Caribbeans). Hyperacute T-waves are the earliest ECG change of acute myocardial infarction. ECG findings of hyperkalaemia include high, tent-shaped T-waves, a small P-wave and a wide QRS complex. Hypokalaemia results in flattened (notched) T-waves, U-waves, ST-segment depression and prolonged QT interval.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 72
Correct
-
A cerebellar tremor can be differentiated from a Parkinsonian tremor in that:
Your Answer: It only occurs during voluntary movements
Explanation:Cerebellar disease leads to intention tremors, which is absent at rest and appears at the onset of voluntary movements. In comparison, Parkinson’s tremor is present at rest. Frequency of tremor is a less reliable means to differentiate between the two as the oscillation amplitude of the tremor is not constant throughout a voluntary action.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 73
Incorrect
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Which name is given to the inferior fascia of the urogenital diaphragm?
Your Answer: Obturator fascia
Correct Answer: Perineal membrane
Explanation:The urogenital fascia is mostly commonly referred to as the perineal membrane. This term refers to an anatomical fibrous membrane in the perineum. It is triangular in shape, and thus at times referred to as the triangular ligament. It is about 4 cm in depth. Its The perineal membrane’s apex is anterior and is separated from the arcuate pubic ligament by an oval opening for the passage of the deep dorsal vein of the penis. The lateral marginas of this triangular ligament are attached on either side to the inferior rami of the pubis and ischium, above the crus penis. Its base faces the rectum, and connects to the central tendinous point of the perineum. The pelvic fascia and Colle’s fascia is fused to the base of this triangle.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 74
Correct
-
Which of these conditions is mithramycin used for?
Your Answer: Hypercalcaemia of malignancy
Explanation:Mithramycin or Plicamycin is a tricyclic pentaglycosidic antibiotic derived from Streptomyces strains. It inhibits RNA and protein synthesis by adhering to DNA. It is used as a fluorescent dye and as an antineoplastic agent. It is also used to reduce hypercalcaemia, especially caused by malignancy. Plicamycin is currently used in multiple areas of research, including cancer cell apoptosis and as a metastasis inhibitor.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 75
Incorrect
-
The posterior boundary of the carotid triangle is bounded by which of the following muscles?
Your Answer: Posterior belly of the digastric
Correct Answer: Sternocleidomastoid
Explanation:The carotid triangle is a portion of the anterior triangle of the neck. It is bounded superiorly by the posterior belly of the digastric muscle, antero-inferiorly by the superior belly of omohyoid and posteriorly by the sternocleidomastoid. The floor is formed by the thyrohyoid, hyoglossus, middle and inferior pharyngeal constrictors and the roof is formed by the skin, superficial fascia, platysma and deep fascia.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 76
Incorrect
-
A 75-year old patient is in atrial fibrallation but has never been on anticoagulation therapy. To reduce the risk of future emboli, she would benefit from starting on long-term warfarin. Arterial emboli leading to acute limb ischaemia most commonly lodge at which one of the following sites?
Your Answer: Popliteal artery
Correct Answer: Common femoral artery
Explanation:The common femoral artery is the commonest site of arterial emboli causing acute limb ischemia. The treatment of choice is urgent femoral embolectomy.
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This question is part of the following fields:
- Cardiovascular
- Pathology
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Question 77
Correct
-
A 55 year-old construction worker is diagnosed with malignant mesothelioma. Exposure to which substance increased his risk in developing mesothelioma?
Your Answer: Asbestos
Explanation:Mesothelioma is a rare, aggressive form of cancer that develops in the lining of the lungs, abdomen or heart. It is linked to inhalation of asbestos commonly used in ship building and the insulation industry. It has no known cure and has a very poor prognosis.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 78
Incorrect
-
The dural venous sinuses are venous channels that drain blood from the brain. This sinuses are located between which structures?
Your Answer: Periosteal and meningeal layers of the arachnoid mater
Correct Answer: Meningeal and periosteal layers of the dura mater
Explanation:The dural venous sinuses lies between the periosteal and meningeal layer of the dura mater. Dural venous sinuses is unique because it does not run parallel with arteries and allows bidirectional flow of blood intracranially as it is valve-less.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 79
Incorrect
-
After surgery, a patient developed a stitch granuloma . Which leukocyte in the peripheral blood will become an activated macrophage in this granuloma?
Your Answer: Neutrophil
Correct Answer: Monocyte
Explanation:Monocytes are leukocytes that protect the body against infections and move to the site of infection within 8-12 hours to deal with it. They are produced in the bone marrow and shortly after being produced are released into the blood stream where they circulate until an infection is detected. When called upon they leave the circulation and transform into macrophages within the tissue fluid and thus gain the capability to phagocytose the offending substance. Monocyte count is part of a complete blood picture. Monocytosis is the state of excess monocytes in the peripheral blood and may be indicative of various disease states. Examples of processes that can increase a monocyte count include: • chronic inflammation • stress response • hyperadrenocorticism • immune-mediated disease • pyogranulomatous disease • necrosis • red cell regeneration.
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This question is part of the following fields:
- General
- Physiology
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Question 80
Correct
-
Which statement is true regarding the diaphragmatic openings:
Your Answer: The thoracic duct passes through the opening at T12
Explanation:The diaphragmatic openings are:
T8 – opening for the inferior vena cavaand the right phrenic nerve
T10 – opening for the oesophagusand the left gastric artery and vein
T12 – opening for the aorta, the thoracic duct and azygos vein.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 81
Incorrect
-
A 56 year old gentleman, who is a chronic smoker presents to the clinic with dyspnoea. His Chest X-ray shows intercostal space widening with increased blackening bilaterally. What is the most likely finding on his pulmonary function test?
Your Answer: Increased FEV1/FVC
Correct Answer: Increased total lung capacity
Explanation:In patients suspected of having chronic obstructive pulmonary disease, pulmonary function testing (PFT) is useful to confirm airway obstruction, to quantify its severity and reversibility, for following disease progression and monitoring response to treatment. These tests include:
FEV1 – volume of air forcefully expired during the first second after a full breath
Forced vital capacity (FVC) – total volume of air expired with maximal force and flow-volume loops. The hallmark of airway obstruction is reduction of FEV1, FVC and the ratio of FEV1/FVC, with a concave pattern in expiratory tracing on the flow-volume loop. FEV1 and forced vital capacity (FVC) are easily measured with office spirometry and are useful to assess the severity of disease. Other parameters include increased total lung capacity, functional residual capacity and residual volume, which can help distinguish chronic obstructive pulmonary disease (COPD) from restrictive pulmonary disease where these values are lower than normal. Along with these, other tests are decreased vital capacity; and decreased diffusing capacity for carbon monoxide (DLCO). DLCO is non-specific and can be low in other disorders that affect the pulmonary vascular bed, such as interstitial lung disease. DLCO is however useful to distinguish COPD from asthma, in which DLCO is normal or elevated.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 82
Correct
-
Lack of findings in the bladder but presence of atypical epithelial cells in urinalysis is most often associated with which of the following conditions?
Your Answer: Transitional cell carcinoma of renal pelvis
Explanation:The presence of atypical cells in urinalysis without findings in the bladder suggests a lesion located higher up, most probably in ureters or renal pelvis. Transitional cell cancer of the renal pelvis is a disease in which malignant cells form in the renal pelvis and is characterised by the presence of abnormal cells in urine cytology.
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This question is part of the following fields:
- Pathology
- Renal
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Question 83
Correct
-
A young male was diagnosed with hepatitis A, which clinically resolved in 2 weeks. What will his liver biopsy done after 6 months show?
Your Answer: Normal architecture
Explanation:Hepatitis A is the most common acute viral hepatitis, more common in children and young adults. It is caused by Hepatitis A virus, which is a single-stranded RNA picornavirus. The primary route of spread of Hepatitis A is the faecal-oral route. Consumption of contaminated raw shellfish is also a likely causative factor. The shedding of the virus in faecal matter occurs before the onset of symptoms and continues a few days after. Hepatitis A does not lead to chronic hepatitis or cirrhosis, and there is no known chronic carrier state. Hence, a biopsy performed after recovery will show normal hepatocellular architecture.
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This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
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Question 84
Correct
-
Where does the ejaculatory duct open into?
Your Answer: Prostatic urethra
Explanation:There are two ejaculatory ducts, one on either side of the midline. Each ejaculatory duct is formed by the union of the duct from the seminal vesicles with the ductus deferens. They start at the base of the prostate and run forward and downward between the middle and lateral lobes and along the side of the prostatic utricle to end in the prostatic urethra.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 85
Incorrect
-
A 65-year-old man with no history of smoking complains of shortness of breath and persistent cough over the past 8 months. He reveals that in the 1960s he worked for several years as a boiler operator. Chest X-ray shows diffuse lung infiltrates. Which of the following is the most probable cause of these findings?
Your Answer: Berylliosis
Correct Answer: Asbestosis
Explanation:Asbestosis is a chronic lung disease which leads to long-term respiratory complications and is caused by the inhalation of asbestos fibres. Symptoms due to long exposure to asbestos usually appear 10 to 40 years after initial exposure and include shortness of breath, cough, weight loss, clubbing of the fingers and chest pain. Typical chest X-ray findings include diffuse lung infiltrates that cause the appearance of shaggy heart borders.
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This question is part of the following fields:
- Pathology
- Respiratory
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Question 86
Correct
-
During a radical mastectomy for advanced breast cancer, the surgeon injured the long thoracic nerve. Which among the following muscles is likely to be affected?
Your Answer: Serratus anterior
Explanation:The long thoracic nerve innervates the serratus anterior muscle which holds the scapula forward and balances the rhomboids and the trapezius muscles which retract the scapula. Injury to this nerve results in a ‘winged scapula’ with a posterior protrusion.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 87
Correct
-
A syndrome responsible for failure to absorb vitamin B12 from the GIT is called?
Your Answer: Pernicious anaemia
Explanation:Pernicious anaemia is a type of autoimmune disease in which antibodies form against the parietal cells or intrinsic factor. Intrinsic factor is required for the absorption of vitamin B12. Blood testing typically shows a macrocytic, normochromic anaemia and low levels of serum vitamin B12. A Schilling test can then be used to distinguish between pernicious anaemia, vitamin B12 malabsorption and vitamin B12 deficiency. Symptoms include shortness of breath, pallor and diarrhoea etc.
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This question is part of the following fields:
- General
- Physiology
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Question 88
Correct
-
A 42 year old man with an abdominal aortic aneurysm (AAA) underwent an abdominal aortic angiography which revealed that his inferior mesenteric artery was occluded. If this patient showed no symptoms, the most likely reason is that the area the inferior mesenteric artery supplies, must be supplied by collateral blood flow from which arteries?
Your Answer: Left and middle colic
Explanation:The arterial branches that form an anastomosis between the superior mesenteric artery and the inferior mesenteric artery are the left colic artery and the middle colic artery. The middle colic artery is the most distal branch of the superior mesenteric artery while the left colic forms the most proximal branch of the inferior mesenteric artery. These two arteries will give collateral blood flow in the case that the inferior mesenteric artery gets occluded. The superior mesenteric artery gives off the following branches; ileocolic, appendicular, ileal artery, right colic and middle colic arteries. The left colic, sigmoid and superior rectal arteries are branches of the inferior mesenteric artery. The marginal artery branches off directly from the abdominal aorta.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 89
Correct
-
During an operation to repair an indirect inguinal hernia, you are asked to indicate the position of the deep inguinal ring. You indicate this as being:
Your Answer: Above the midpoint of the inguinal ligament
Explanation:The deep inguinal ring is near the midpoint of the inguinal ligament, below the anterior superior iliac spine. It is lateral to the inferior epigastric artery. The superficial ring, however, is found above the pubic tubercle. The supravesical fossa is the space between the median and medial umbilical folds.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 90
Correct
-
A 6 year-old boy is brought to you coughing. He is suspected to have aspirated a Lego piece which he was seen playing with. Where would you expect the piece to be?
Your Answer: Right main bronchus
Explanation:Inhaled objects are more likely to enter the right lung for several reasons. First the right bronchus is shorter, wider and more vertical than the left bronchus. Also, the carina (a ridge-like structure at the point of tracheal bifurcation) is set a little towards the left. The terminal bronchiole is a very small space and impossible for the seed to lodge here.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 91
Correct
-
Acute respiratory distress syndrome (ARDS) is a medical condition that occurs in critically ill patients, and can be triggered by events such as trauma and sepsis. Which of the following variables is most likely to be lower than normal in a patient with ARDS?
Your Answer: Lung compliance
Explanation:Acute (or Adult) respiratory distress syndrome (ARDS) is a medical condition occurring in critically ill patients characterized by widespread inflammation in the lungs. The development of acute respiratory distress syndrome (ARDS) starts with damage to the alveolar epithelium and vascular endothelium, resulting in increased permeability to plasma and inflammatory cells. These cells pass into the interstitium and alveolar space, resulting in pulmonary oedema. Damage to the surfactant-producing type II cells and the presence of protein-rich fluid in the alveolar space disrupt the production and function of pulmonary surfactant, leading to micro atelectasis and impaired gas exchange. The pathophysiological consequences of lung oedema in ARDS include a decrease in lung volumes, compliance and large intrapulmonary shunts. ARDS may be seen in the setting of pneumonia, sepsis, following trauma, multiple blood transfusions, severe burns, severe pancreatitis, near-drowning, drug reactions, or inhalation injuries.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 92
Incorrect
-
Arterial blood gas analysis of a man admitted with acute exacerbation of chronic obstructive pulmonary disease (COPD) showed the following: pH = 7.28, p(CO2) = 65.5 mmHg, p(O2)= 60 mmHg and standard bicarbonate = 30.5 mmol/l. This patient had:
Your Answer: Mixed acidosis
Correct Answer: Respiratory acidosis
Explanation:Acidosis with high p(CO2) and normal standard bicarbonate indicates respiratory acidosis, commonly seen in acute worsening of COPD patients. Respiratory acidosis occurs due to alveolar hypoventilation which leads to increased arterial carbon dioxide concentration (p(CO2)). This in turn decreases the HCO3 –/p(CO2) and decreases pH. In acute respiratory acidosis, the p(CO2) is raised above the upper limit of normal (over 45 mm Hg) with a low pH. However, in chronic cases, the raised p(CO2) is accompanied with a normal or near-normal pH due to renal compensation and an increased serum bicarbonate (HCO3 – > 30 mmHg).
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 93
Correct
-
A surgeon ligates the left middle suprarenal artery while carrying out a left adrenalectomy. Where does the left middle suprarenal artery originate?
Your Answer: Abdominal aorta
Explanation:Middle suprarenal arteries arise from either side of the abdominal aorta, opposite the superior mesenteric artery.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 94
Incorrect
-
Which of the following is a true statement regarding the pupil?
Your Answer: Increase in sympathetic activity in fibres innervating the inner eye muscles during darkness results in pupil constriction
Correct Answer: Phentolamine causes pupil constriction
Explanation:A balance between the sympathetic tone to the radial fibres of the iris and parasympathetic tone to the pupillary sphincter muscle determines the pupil size. Phentolamine (α-adrenergic receptor blocker) causes pupillary constriction. Dilatation of the pupil occurs with increased sympathetic activity, decreased parasympathetic activity during darkness or block of muscarinic receptors by atropine.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 95
Incorrect
-
A 50 year old man on warfarin therapy following insertion of a pacemaker presented with epistaxis. Which of the following is true regarding blood coagulation?
Your Answer: Disseminated intravascular coagulation (DIC) results in depletion of fibrin split products
Correct Answer: Patients with haemophilia A usually have a normal bleeding time
Explanation:A prolonged bleeding time is seen in platelet disorders like thrombocytopenia. Patients with haemophilia A or B have a prolonged PTT but not a prolonged bleeding time.
Ca2+ is necessary for coagulation.
von Willebrand factor is an important part of the factor VIII complex and promotes platelet adhesion and aggregation.
DIC results in depleted coagulation factors and accumulation of fibrin.
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This question is part of the following fields:
- General
- Physiology
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Question 96
Incorrect
-
When does the heart rate decrease?
Your Answer: On inspiration
Correct Answer: Pressure on the eyeball
Explanation:Various vagotonic manoeuvres (e.g. Valsalva manoeuvre, carotid sinus massage, pressure on eyeballs, ice-water facial immersion, swallowing of ice-cold water) result in increased parasympathetic tone through the vagus nerve which results in a decrease in heart rate. These manoeuvres may be clinically useful in terminating supraventricular arrhythmias.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 97
Incorrect
-
If a tumour is found in both lobes of the prostate, without nodal involvement or metastases, a histological grade of G2 and elevated PSA, what is the overall prostatic cancer stage?
Your Answer: Stage III
Correct Answer: Stage II
Explanation:The AJCC uses the TNM, Gleason score and PSA levels to determine the overall stage of prostatic cancer. This staging is as follows:
Stage I: T1, N0, M0, Gleason score 6 or less, PSA less than 10; or T2a, N0, M0, Gleason score 6 or less, PSA less than 10
Stage IIa: T1, N0, M0, Gleason score of 7, PSA less than 20; or T1, N0, M0, Gleason score of 6 or less, PSA at least 10 but less than 20; or T2a or T2b, N0, M0, Gleason score of 7 or less, PSA less than 20
Stage IIb: T2c, N0, M0, any Gleason score, any PSA; or T1 or T2, N0, M0, any Gleason score PSA of 20 or more; or T1 or T2, N0, M0, Gleason score of 8 or higher, any PSA
Stage III: T3, N0, M0, any Gleason score, any PSA Stage IV: T4, N0, M0,any Gleason score, any PSA; or any T, N1, M0,any Gleason score, any PSA; or Any T, any N, M1, any Gleason score, any PSA.
The patient in this case has a T2 N0 M0 G2 tumour, meaning it belongs in stage II
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This question is part of the following fields:
- Pathology
- Urology
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Question 98
Incorrect
-
Which type of contractions are responsible for the propulsion of chyme along the small intestine?
Your Answer: Peristaltic waves
Correct Answer: Segmentation
Explanation:Two major types of intestinal contractions are segmentation and peristalsis:
Segmentation occurs most frequently and primarily involves circular muscle. It is essentially a contraction of 2- or 3-cm long intestinal segments while the muscle on either side of it relaxes. Chyme in the segment is displaced in both directions. As the contracted segment relaxes, the previously relaxed segments on either side may contract. This efficiently mixes the chyme with the digestive secretions and exposes the mucosal absorptive surface to the luminal contents. It also serves a propulsive function and contributes to the movement of chyme.
Peristalsis is a propulsive wave of contraction that is initiated by intestinal distension. It is short lived and travels only a few centimetres before dying out. The combined effects of intestinal peristalsis and segmentation provide for both adequate mixing of the intestinal contents and slow, steady movement of chyme.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 99
Incorrect
-
A week after a renal transplant the patient received antilymphocyte globulins. Shortly after she developed fever and hypotension. Which of the following mechanisms is involved in this response?
Your Answer: Type IV hypersensitivity
Correct Answer: Type III hypersensitivity
Explanation:Type III hypersensitivity is characterized by soluble immune complexes which are aggregations of IgG and IgM antibodies with antigens that deposit in different tissues e.g. the skin, joints, kidneys. They can then trigger an immune response by activating the complement cascade. This reaction can take hours to develop and examples include: immuno-complex glomerulonephritis, rheumatoid arthritis, SLE, subacute bacterial endocarditis, arthus reaction and serum sickness.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 100
Incorrect
-
Multiple, non-tender lymphadenopathy with biopsy showing several crowded follicles of small, monomorphic lymphocytes and the absence of Reed-Sternberg cells is seen in which of the following?
Your Answer: Hodgkin’s disease, lymphocyte predominance type
Correct Answer: Poorly differentiated lymphocytic lymphoma
Explanation:Malignant lymphoma usually causes non-tender lymphadenopathy, unlike the tender lymphadenopathy caused by infections (including infectious mononucleosis caused by Epstein-Barr virus). Also, the lymphoid hyperplasia seen in infectious mononucleosis is benign and polyclonal.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 101
Correct
-
What is expected from complete transection of the inferior gluteal nerve when it emerges from the greater sciatic foramen?
Your Answer: Extension of the thigh would be the action most affected
Explanation:As the inferior gluteal nerve emerges from the greater sciatic foramen below the piriformis muscle, it divides into branches and enters the gluteus maximus muscle which extends the femur and bends the thigh in line with the body.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 102
Correct
-
A 34-year-old man is receiving chemotherapy for non-Hodgkin's lymphoma. Which of the following chemotherapy regimens would be used in this case?
Your Answer: CHOP
Explanation:CHOP is the acronym for a chemotherapy regimen used in the treatment of non-Hodgkin’s lymphoma, comprising cyclophosphamide, hydroxyrubicin (adriamycin), vincristine and prednisone. This regimen can also be combined with the monoclonal antibody rituximab if the lymphoma is of B cell origin; this combination is called R-CHOP.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 103
Correct
-
Coagulation in the body (in vivo) is a process in which several proteins known as coagulation factors are activated in a cascade effect to stop bleeding. Which of the following initiates this cascade effect?
Your Answer: Tissue factor
Explanation:Tissue factor (TF), also known as ‘factor III’ or ‘thromboplastin’, is an anti-coagulation protein that initiates the extrinsic coagulation. TF acts as a transmembrane receptor for Factor VII/VIIa . It is expressed by endothelial cells but also certain tissues, such as the heart and brain.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 104
Incorrect
-
Biopsy of a neoplastic mass was performed. Histologic examination of the specimen showed spindle shaped cells with high nuclear/cytoplasm ratio on immunohisto chemical staining. These pleomorphic cells were vimentin positive, cytokeratin negative and cd45 negative. This type of neoplasm is most commonly found in which patient?
Your Answer: A 35-year-old woman with a left breast mass and enlarged axillary lymph nodes
Correct Answer: A 15-year-old boy with a mass in the left femur and lung metastases
Explanation:A histology report that describes spindle shaped cells which are vimentin positive suggests osteosarcoma and hematogenous spread to the lungs.
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This question is part of the following fields:
- Neoplasia; Orthopaedics
- Pathology
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Question 105
Correct
-
Which of the following is found to be elevated in a case of hepatocellular carcinoma?
Your Answer: AFP
Explanation:Alpha-fetoprotein (AFP) is a glycoprotein that is normally produced by the yolk sac of the embryo, and then the fetal liver. It is elevated in the new-born and thus, also in the pregnant women. Eventually, it decreases in the first year of life to reach the adult normal value of < 20 ng/ml by 1 year of age. Markedly elevated levels (>500 ng/ml) in a high-risk patient is considered diagnostic for primary hepatocellular carcinoma (HCC). Moreover, due to smaller tumours secreting less quantities of AFP, rising levels can be a better indication. However, not all hepatocellular carcinomas produce AFP. Also, the level of AFP is not a prognostic factor. Populations where hepatitis B and HCC are common (e.g.: sub-Saharan Africans, ethnic Chinese) can see AFP levels as high as 100,000 ng/ml, whereas levels are low (about 3000 ng/ml) in regions with lesser incidences of HCC.
AFP can also be elevated up to 500 ng/ml in conditions like embryonic teratocarcinomas, hepatoblastomas, fulminant hepatitis, hepatic metastases from gastrointestinal tract cancers, some cholangiocarcinomas). Lesser values are seen in acute and chronic hepatitis.
Overall, the sensitivity of AFP value ≥20 ng/ml is 39-64% and the specificity is 76%–91%. Value of 500 ng/ml is considered as the diagnostic cut-off level for HCC.
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This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
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Question 106
Incorrect
-
The wound healing process is documented in patients undergoing laparoscopic procedures. The port incisions are sutured closed and the wounds observed every few weeks for re-epithelialisation and tensile strength. Which substance is mostly likely to be found at a cellular level involved in wound healing?
Your Answer: Collagen
Correct Answer: Tyrosine kinase
Explanation:Cell surface growth factor receptors require intercellular proteins such as tyrosine kinase which are necessary to initiate a series of events that eventually lead to cell division and growth. Tyrosine kinase is an enzyme that transfers a phosphate group to the tyrosine residue in a protein. This phosphorylation will lead to an up regulation of the enzyme activity.
Fibronectin acts in the extracellular matrix to bind macromolecules (such as proteoglycans) via integrin receptors to aid attachment and migration of cells.
Laminin is an extracellular matrix component that is abundant in basement membranes.
Hyaluronic acid is one of the proteoglycans in the extracellular matrix.
Collagen fibres are part of the extracellular matrix that gives strength and stability to connective tissues.
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This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
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Question 107
Correct
-
The vagus nerve passes through which of the following foramen?
Your Answer: Jugular foramen
Explanation:The jugular foramen is a large foramen in the base of the skull. It is located behind the carotid canal and is formed in front by the petrous portion of the temporal bone, and behind by the occipital bone. Cranial nerves IX, X, and XI and the internal jugular vein pass through the jugular foramen.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 108
Incorrect
-
Whilst snorkelling, a 30-year old gentleman has the respiratory rate of 10/min, tidal volume of 550 ml and an effective anatomical dead space of 250 ml. What is his alveolar ventilation?
Your Answer: 5000 ml/min
Correct Answer: 3000 ml/min
Explanation:Alveolar ventilation is the amount of air reaching the alveoli per minute. Alveolar ventilation = respiratory rate × (tidal volume – anatomical dead space volume). Thus, alveolar ventilation = 10 × (550 − 250) = 3000 ml/min.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 109
Incorrect
-
A 47-year-old male smoker, who had been self-medicating with oral steroids for the last two years due to persistent breathlessness presented to the doctor complaining of a productive cough, fever and chest pain. A chest X-ray revealed bilateral patchy opacities. He was diagnosed with bilateral bronchopneumonia. Which of these organisms is most probably causing these findings?
Your Answer: Haemophilus influenzae
Correct Answer: Nocardia asteroides
Explanation:Nocardia is a Gram-positive aerobic actinomycete. Several species have been identified but the most common human pathogen is Nocardia asteroides. The predominant clinical finding in the majority of patients affected by nocardiosis is pulmonary disease. Predisposing factors for pulmonary nocardiosis include leukaemia, human immunodeficiency virus (HIV) infection, organ transplantation, diabetes and receiving prolonged corticosteroids.
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This question is part of the following fields:
- Pathology
- Respiratory
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Question 110
Incorrect
-
A 68-year-old man underwent sigmoid resection with diverting colostomy for a ruptured sigmoid diverticulum 10 days ago. He received gentamicin and ampicillin post-op. 2 days after he was discharged from the hospital, he was readmitted because of high grade fever and chills. His blood culture grew Gram-negative bacilli. Which organism is most likely responsible for the patient's infection?
Your Answer: Escherichia coli
Correct Answer: Bacteroides fragilis
Explanation:Bacteroides fragilis is an anaerobic, Gram-negative, rod-shaped bacterium. It is part of the normal flora of the human colon and is generally a commensal, but can cause infection if displaced into the bloodstream or surrounding tissue following surgery, disease, or trauma.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 111
Incorrect
-
A 45 -year-old female is recently diagnosed with breast cancer. She has a 8-cm-diameter mass in her left breast, with enlarged left axillary node. What is the most likely stage of her disease?
Your Answer: IIIB
Correct Answer: IIIA
Explanation:Stage IIIA breast cancer is T0–2 N2 M0 or T3 N1-2 M0 disease. It describes invasive breast cancer in which either: the tumour is smaller than 5 cm in diameter and has spread to 4 to 9 axillary lymph nodes; or it is found through imaging studies or clinical exam to have spread to internal mammary nodes (near the breastbone found during imaging tests or a physical exam); or the tumour is larger than 5 cm and has spread to 1 to 9 axillary nodes, or to internal mammary nodes. In this stage, the cancer has not metastasized (spread to distant sites).
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 112
Correct
-
Pseudomonas aeruginosa is a multidrug resistant pathogen that causes hospital-acquired infections. It is usually treated with piperacillin or another antibiotic. Which of the following is the other antibiotic?
Your Answer: Azlocillin
Explanation:Azlocillin, like piperacillin, is an acylampicillin antibiotic with an extended spectrum of activity and greater in vitro potency than the carboxypenicillins. Azlocillin is similar to mezlocillin and piperacillin. It demonstrates antibacterial activity against a broad spectrum of bacteria, including Pseudomonas aeruginosa.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 113
Incorrect
-
Congenital anomalies of genitourinary tract are more common than any other system. Which of the following anomalies carries the greatest risk of morbidity?
Your Answer:
Correct Answer: Bladder exstrophy
Explanation:Bladder exstrophy is the condition where the urinary bladder opens from the anterior aspect suprapubically. The mucosa of the bladder is continuous with the abdominal skin and there is separation of the pubic bones. The function of the upper urinary tract remains normal usually. Treatment consists of surgical reconstruction of the bladder and returning it to the pelvis. There can be a need for continent urinary diversion along with reconstruction of the genitals.
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This question is part of the following fields:
- Pathology
- Renal
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Question 114
Incorrect
-
A patient with this type of tumour is advised to follow up regularly for monitoring of tumour size as there is a strong correlation with malignant potential and tumour size. Which of the following is the most likely tumour in this patient?
Your Answer:
Correct Answer: Renal adenocarcinoma
Explanation:The distinction between a benign renal adenoma and renal adenocarcinoma is commonly made on the basis of size. Tumours less than 2 cm in size rarely become malignant as opposed to those greater than 3 cm.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 115
Incorrect
-
Most of the coagulation factors are serine proteases. Which of the following is not one of them?
Your Answer:
Correct Answer: Factor XIII
Explanation:Serine protease coagulation factors include: thrombin, plasmin, Factors X, XI and XII. Factor VIII and factor V are glycoproteins and factor XIII is a transglutaminase.
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This question is part of the following fields:
- General
- Physiology
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Question 116
Incorrect
-
A 25 year old male patient who had sustained a stab wound in the middle of the posterior aspect of the left thigh, was discharged from hospital after dressing and antibiotic prophylaxis. Later on the patient developed bleeding through the wound and upon review, the source was discovered to be an artery that is the direct source of the medial and lateral circumflex arteries. Which is this artery that was injured?
Your Answer:
Correct Answer: Profunda femoris artery
Explanation:The medial and lateral circumflex arteries are direct branches of the Profunda femoris artery otherwise also known as the deep artery of the thigh. The Profunda femoris artery arises from the femoral artery just below the inguinal ligament (approximately 2-5cm below it).
The following are the branches of the deep artery of the thigh:
Lateral circumflex femoral artery
Medial circumflex femoral artery
Perforating arteries
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 117
Incorrect
-
When exposing the right saphenofemoral junction for flush-ligation of the saphenous vein, which of the following is the most likely to be seen passing through this opening?
Your Answer:
Correct Answer: Superficial external pudendal artery
Explanation:The saphenous opening is an oval opening in the fascia lata. It is covered by the cribriform fascia and It is so called because it is perforated by the great saphenous vein and by numerous blood and lymphatic vessels and the superficial external pudendal artery pierces it.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 118
Incorrect
-
Langhans giant cells are characteristically seen in which type of inflammation?
Your Answer:
Correct Answer: Granulomatous inflammation
Explanation:Langhans giant cells are characteristically seen in granulomatous inflammation. They form when epithelioid cells fuse together. They usually contain a nuclei with a horseshoe-shaped pattern in the periphery of the cell.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 119
Incorrect
-
Glucose is not secreted by the kidneys, and is filtered without a limit. What is the transport maximum for glucose?
Your Answer:
Correct Answer: 300 mg/dl
Explanation:Transport maximum (or Tm) refers to the point at which increases in concentration do not result in an increase in movement of a substance across a membrane. Glucose is not secreted, thus excretion = filtration – reabsorption. Both filtration and reabsorption are directly proportional to the concentration of glucose in the plasma. However, reabsorption has a transport maximum of about 300 mg/dl in healthy nephrons, while filtration has effectively no limit (within reasonable physiological ranges). So, if the concentration rises above 300 mg/dl, the body cannot retain all the glucose, leading to glucosuria. Glucosuria is nearly always caused by elevated blood glucose levels, most commonly due to untreated diabetes mellitus.
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This question is part of the following fields:
- Physiology
- Renal
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Question 120
Incorrect
-
Which of the following is not seen as a complication of wound healing?
Your Answer:
Correct Answer: Malignancy
Explanation:Complications in wound healing can originate due to abnormalities in the repair process. These abnormalities are :
1) Deficient scar formation: insufficient granulation tissue can lead to wound dehiscence and ulceration. Dehiscence or wound rupture is seen most commonly in abdominal surgery due to increased intraabdominal pressure. Ulcerations are common in extremity wounds due to inadequate vascularization.
2) Excessive formation of repair components: collagen being laid down may begin normally however later lead to a raised scar also called a hypertrophic scar, which can extend beyond its boundaries to form a keloid and
3) Formation of contractures.
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This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
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Question 121
Incorrect
-
What is the normal glomerular filtration rate?
Your Answer:
Correct Answer: 125 mL/min
Explanation:The normal glomerular filtration rate (GFR) in humans is 125 mL/min. After the age of 40, GFR decreases progressively by about 0.4–1.2 mL/min per year.
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This question is part of the following fields:
- Physiology
- Renal
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Question 122
Incorrect
-
A 60-year old man with a left-sided indirect inguinal hernia underwent emergency surgery to relieve large bowel obstruction resulting from a segment of the bowel being strangulated in the hernial sac. The most likely intestinal segment involved is:
Your Answer:
Correct Answer: Sigmoid colon
Explanation:The sigmoid colon is the most likely segment involved as it is mobile due to the presence of the sigmoid mesocolon. The descending colon, although on the left side, is a bit superior and is also retroperitoneal. The ascending colon and caecum are on the right side of the abdomen. The rectum is too inferior to enter the deep inguinal ring and the transverse colon is too superior to be involved.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 123
Incorrect
-
A lesion involving the lateral portion of the dorsal columns at the level of the nape of the neck will most likely affect:
Your Answer:
Correct Answer: Vibratory sensations from the ipsilateral arm
Explanation:At the level mentioned in the question, the lateral portion of dorsal columns comprises of the fasciculus cuneatus. Axons carrying the sensations of touch, vibration and proprioception from the ipsilateral arm enter the spinal cord and ascend in the fasciculus cuneatus, synapsing in the nucleus cuneatus of the caudal medulla. Secondary neurons from this nucleus give rise to internal arcuate fibres, which decussate and ascend to the thalamus as the medial lemniscus. Tertiary neurons from there project to the ipsilateral somatosensory cortex. Thus, any damage to the fasciculus cuneatus will result in a deficit in tactile, proprioceptive and vibratory sensations in the ipsilateral arm, and not the contralateral arm.
Fine motor control of the fingers is mainly carried by the ipsilateral lateral corticospinal tract in the lateral funiculus of the cord. Motor control of the contralateral foot is carried by the ipsilateral corticospinal tract in the lateral funiculus of the cord. Lack of sweating of the face could be produced by interruption of sympathetic innervation. Proprioception from the ipsilateral leg is carried by the fasciculus gracilis in the medial part of the dorsal columns.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 124
Incorrect
-
An infant, 5 weeks and 6 days old born with a large sub-aortic ventricular septal defect, is prepared for pulmonary artery banding through a left thoracotomy (the child is not fit for a surgical closure). The surgeon initially passes his index finger immediately behind two great arteries in the pericardial sac to mobilise the great arteries in order to pass the tape around the pulmonary artery. Into which space is the surgeon's finger inserted?
Your Answer:
Correct Answer: Transverse pericardial sinus
Explanation:Cardiac notch: is an indentation on the left lung of the heart.
Coronary sinus: a venous sinus on the surface of the heart (the posterior aspect) that receives blood from the smaller veins that drain the heart.
Coronary sulcus: a groove on the heart between the atria and ventricles.
Transverse pericardial sinus: located behind the aorta and pulmonary trunk and anterior to the superior vena cava.
Oblique pericardial sinus: located behind the left atrium. Accessed from the inferior side (or the apex) of the heart upwards.
Horizontal pericardial sinus: this is a made-up term.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 125
Incorrect
-
Which of the following variables are needed to calculate inspiratory reserve volume of a patient?
Your Answer:
Correct Answer: Tidal volume, vital capacity and expiratory reserve volume
Explanation:Vital capacity = inspiratory reserve volume + tidal volume + expiratory reserve volume. Thus, inspiratory reserve volume can be calculated if tidal volume, vital capacity and expiratory reserve volume are known.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 126
Incorrect
-
A 26-year-old female patient had the following blood report: RBC count = 4. 0 × 106/μl, haematocrit = 27% and haemoglobin = 11 g/dl, mean corpuscular volume (MCV) = 80–100 fl, mean corpuscular haemoglobin concentration (MCHC) = 31–37 g/dl. Which of the following is correct regarding this patient’s erythrocytes:
Your Answer:
Correct Answer: Normal MCV
Explanation:MCV is the mean corpuscular volume and it is calculated from the haematocrit and the RBC count. It is normally 90 fl. Mean corpuscular haemoglobin concentration (MCHC) [g/dl] = haemoglobin [g/dl]/haematocrit = 11/0.27 = 41 g/dl and is higher than normal range (32 to 36 g/dL).
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This question is part of the following fields:
- General
- Physiology
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Question 127
Incorrect
-
A 45-year old lady underwent biopsy of a soft, fleshy mass involving her left breast. The biopsy showed lymphoid stroma with minimal fibrosis, surrounding sheets of large vesicular cells with frequent mitoses. Which condition is she most likely suffering from?
Your Answer:
Correct Answer: Medullary carcinoma of breast
Explanation:Medullary carcinoma is a malignant tumour of the breast with well-defined boundaries and accounts for 5% of all breast cancers. Other special features include a larger size of the neoplastic cells and presence of lymphoid cells at tumour edge. Differential diagnosis includes invasive ductal carcinoma. Prognosis is usually good.
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This question is part of the following fields:
- Pathology
- Women's Health
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Question 128
Incorrect
-
During an operation to repair a hiatal hernia, the coeliac branch of the posterior vagal trunk is injured. This damage would affect muscular movements as well as some secretory activities of the gastrointestinal tract. Which gastrointestinal segment is LEAST likely to be affected?
Your Answer:
Correct Answer: Sigmoid colon
Explanation:The vagus nerve supplies the parasympathetic fibres to the abdominal structures that are receive arterial supply from the coeliac trunk or superior mesenteric artery i.e. up to the transverse colon. The end of the transverse colon and the gastrointestinal structures distal to this point receive parasympathetic innervation from the pelvic splanchnic nerves and blood from the inferior mesenteric artery(IMA). The ascending colon, caecum, jejunum and ileum would all, thus, be affected by this damage. Sigmoid colon would not be affected.
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This question is part of the following fields:
- Abdomen
- Anatomy
-
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Question 129
Incorrect
-
Extracellular body fluid as compared with intracellular body fluid:
Your Answer:
Correct Answer: Is relatively rich in glucose
Explanation:The percentages of body water contained in various fluid compartments add up to total body water (TBW). This water makes up a significant fraction of the human body, both by weight and by volume. Ensuring the right amount of body water is part of fluid balance, an aspect of homeostasis. The extracellular fluid (ECF) includes all fluids outside the cells. This fluid can be divided into three fluid departments: interstitial (in the tissue spaces) fluid, blood plasma and lymph, and specialised compartments called transcellular fluid. The extracellular fluid surrounds all the cells in the body and is in equilibrium with the intracellular fluid. So, its composition must remain fairly constant even though substances are passing into and out of the cells. The interstitial fluid, though called a fluid, is in a reality a gel-like composition made up of: water, proteoglycan molecules and collagen. The extracellular fluid constitutes 40% of total body water, with intracellular fluid making up the remaining 60%. It is relatively rich in glucose.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 130
Incorrect
-
A 76 year old man who presented with lower back pain is diagnosed with prostatic carcinoma that has metastasized to his lumber spine. Which of the following markers is characteristically elevated?
Your Answer:
Correct Answer: PSA
Explanation:Spread of prostatic carcinoma is common to the lumbar spine and pelvis. This results in osteoblastic metastases that will present as lower back pain with increased alkaline phosphatase, prostatic acid phosphates and PSA. PSA is more specific and a PSA > 10 ng/ml for any age is worrisome.
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This question is part of the following fields:
- Neoplasia; Urology
- Pathology
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Question 131
Incorrect
-
A 60-year old woman who has a left sided post-pneumonic effusion, was to have some pleural fluid aspirated for culture and sensitivity. If the medical intern in charge of the procedure decided to aspirate while the patient is sitting up on her bed, where in the pleural cavity would the fluid tend to accumulate?
Your Answer:
Correct Answer: Costodiaphragmatic recess
Explanation:The lowest part of the pleural cavity is the costodiaphragmatic recess and it the space in which the pleural fluid will accumulate when the patient sits up.
The cupola is part of the pleural cavity that extends into the root of the neck above the first rib.
The costomediastinal recess is the junction at which the costal pleura becomes the mediastinal pleura.
The middle mediastinum is the part of the mediastinum that is occupied by the heart.
The hilar reflection is the point where the mediastinal pleura is reflected to continue on as the visceral pleura.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 132
Incorrect
-
What is the primary function of the Kupffer cells found in the liver?
Your Answer:
Correct Answer: Recycling of old red blood cells
Explanation:Kupffer cells found in the liver are part of the monocyte-reticular system. They are specialised macrophages and primarily function to recycle old and damaged RBCs. The RBCs are phagocytosed and the haemoglobin is broken down into haem and globin. The haem is further broken down into iron that is recycled and bilirubin that is conjugated with glucuronic acid and excreted in the bile.
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This question is part of the following fields:
- Inflammation & Immunology; Hepatobiliary
- Pathology
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Question 133
Incorrect
-
Which of the following is true about a patient who has undergone total colectomy and ileostomy?
Your Answer:
Correct Answer: Following total colectomy and ileostomy, the volume and water content of ileal discharge decreases over time
Explanation:After a patient has undergone total colectomy and ileostomy, the volume of ileal discharge, along with its water content gradually decreases over time. Post surgery, most patients can live a normal life. Iron and vitamin B12 absorption do not take place in the colon and hence are not affected significantly by a colectomy.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 134
Incorrect
-
Which of the following is the most likely cause of massive splenomegaly in a 35-year old gentleman?
Your Answer:
Correct Answer: Myelofibrosis
Explanation:Causes of massive splenomegaly include chronic myelogenous leukaemia, chronic lymphocytic leukaemia, lymphoma, hairy cell leukaemia, myelofibrosis, polycythaemia vera, sarcoidosis, Gaucher’s disease and malaria.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 135
Incorrect
-
A CT scan of 65 year old male patient at an outpatient clinic suggested a bone tumour at the stylomastoid foramen. Which of the following cranial nerves is likely to be affected with this tumour?
Your Answer:
Correct Answer: VII
Explanation:Cranial nerve VII, the facial nerve, is found in the internal acoustic canal and runs through this canal into the facial canal before exiting through the stylomastoid foramen. In the case of a bone tumour at the stylomastoid process, the facial nerve is the nerve that will most likely be affected.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 136
Incorrect
-
Which tumour site is more commonly involved in adults than in children?
Your Answer:
Correct Answer: Lung
Explanation:In adults, the most common primary site of tumour is in the lungs, compared to children wherein the most common primary site is the blood.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 137
Incorrect
-
After finding elevated PSA levels, a 69-year-old man undergoes a needle biopsy and is diagnosed with prostatic cancer. What is the stage of this primary tumour?
Your Answer:
Correct Answer: T1c
Explanation:The AJCC uses a TNM system to stage prostatic cancer, with categories for the primary tumour, regional lymph nodes and distant metastases:
TX: cannot evaluate the primary tumour T0: no evidence of tumour
T1: tumour present, but not detectable clinically or with imaging T1a: tumour was incidentally found in less than 5% of prostate tissue resected (for other reasons)
T1b: tumour was incidentally found in more than 5% of prostate tissue resected
T1c: tumour was found in a needle biopsy performed due to an elevated serum prostate-specific antigen
T2: the tumour can be felt (palpated) on examination, but has not spread outside the prostate
T2a: the tumour is in half or less than half of one of the prostate gland’s two lobes
T2b: the tumour is in more than half of one lobe, but not both
T2c: the tumour is in both lobes
T3: the tumour has spread through the prostatic capsule (if it is only part-way through, it is still T2)
T3a: the tumour has spread through the capsule on one or both sides
T3b: the tumour has invaded one or both seminal vesicles
T4: the tumour has invaded other nearby structures.
In this case, the tumour has a T1c stage.
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This question is part of the following fields:
- Pathology
- Urology
-
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Question 138
Incorrect
-
Calculate the cardiac output in an adult male with the following parameters:
Heart rate 70 beats/min
Arterial [O2] 0.24 ml O2/min
Venous [O2] 0.16 ml O2/mi
Whole body O2 consumption 500 ml/min
Pulmonary diastolic pressure 15 mmHg
Pulmonary systolic pressure 25 mmHg
Wedge pressure 5 mmHg.Your Answer:
Correct Answer: 6.25 l/min
Explanation:As per Fick’s principle, VO2 = (CO × CAO2) – (CO × CVO2) where VO2 = oxygen consumption, CO = cardiac output, CAO2 = oxygen concentration of arterial blood and CVO2 = oxygen concentration of venous blood. Thus, CO = VO2/CAO2– CVO2, CO = 500/0.24 – 0.16, CO = 500/0.8, CO = 6.25 l/min.
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This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 139
Incorrect
-
Which of the following brings about a reduction in gastric blood flow?
Your Answer:
Correct Answer: Vasopressin
Explanation:Gastric blood flow is increased by vagal stimulation, gastrin, histamine and acetylcholine as they stimulate gastric section and the production of vasodilator metabolites. Acetylcholine and histamine also have a direct action on the gastric arterioles. Similarly, gastric blood flow is reduced by inhibitors of secretion – catecholamines, secretin and vasopressin.
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This question is part of the following fields:
- Gastroenterology
- Physiology
-
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Question 140
Incorrect
-
T lymphocytes that express the MCH type II antigen are most likely to produce which of the following cytokines?
Your Answer:
Correct Answer: Gamma interferon
Explanation:Interferon gamma is a soluble cytokine previously known as the macrophage activating factor. It is the only member belonging to the type II class of the interferons. It is secreted by a number of cells taking part in the immune reaction including: T-helper cells (CD-4), cells with immunological memory (CD45PA), killer cells (CD8), dendrite cells (CD23,35), natural killer cells (CD16) and B lymphocytes (CD22,CD23). It has both a defending as well as a pathological effect. It induces differentiation in the myeloid cell in the bone marrow. If macrophages are infected by parasites it activates the macrophages to destroy them. IFN-γ strengthens the anti-tumour activities of the cytotoxic lymphocytes. Together with CD4 or CD8 toxins, produced by lymphocytes, it suppresses the growth of the tumour cells. along with these functions it increases the non specific response of the natural killer cells, causing changes in the cell membrane surface to prevent adhesion and penetration of a virus. It can either increase or decrease B cell response and it activates osteoclasts which increases bone resorption.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 141
Incorrect
-
Which of the following is true about myasthenia gravis?
Your Answer:
Correct Answer: Response of skeletal muscle to nerve stimulation is weakened
Explanation:An autoimmune disorder, myasthenia gravis leads to progressive muscle weakness. It occurs due to formation of antibodies against the nicotinic acetylcholine (ACh) receptor of the motor endplate, which leads to impaired neuromuscular transmission. Thus, nerve stimulation will lead to a weakened muscle response, but direct electrical stimulation will bring about a normal response. Diagnostic test includes improvement of muscle weakness by small doses of acetylcholinesterase inhibitors (physostigmine or edrophonium). However, a large dose of physostigmine worsens the weakness due to desensitisation of the endplate to persistent Ach. One of the investigative tools includes radiolabelled snake venom α-bungarotoxin. It is an in vitro study performed on muscle biopsy specimens and used to quantify the number of ACh receptors at the motor endplate.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 142
Incorrect
-
The collaborative effort of the lateral pterygoid muscles produces which action on the jaw?
Your Answer:
Correct Answer: Protrude the mandible
Explanation:The combined effort of the lateral pterygoid muscles results in the protrusion of the mandible. The lateral pterygoid muscle is a muscle of mastication located superiorly to the medial pterygoid muscle and has two heads. The superior head originates on the infratemporal surface and infratemporal crest of the greater wing of the sphenoid bone, and the inferior head on the lateral surface of the lateral pterygoid plate. The insertion of this muscle is on the front margin of the articular disc of the temporomandibular joint. The unilateral contraction of the pterygoid muscle results in the laterotrusion of the mandible. It is important to note that the lateral pterygoid muscle is the only muscle of mastication that can open the jaw.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 143
Incorrect
-
Whilst snorkelling, a 30-year old gentleman has the respiratory rate of 10/min, tidal volume of 550 ml and an effective anatomical dead space of 250 ml. Which of the following will bring about a maximum increase in his alveolar ventilation?
Your Answer:
Correct Answer: A 2x increase in tidal volume and a shorter snorkel
Explanation:Alveolar ventilation = respiratory rate × (tidal volume − anatomical dead space volume). Increase in respiratory rate simply causes movement of air in the anatomical dead space, with no contribution to the alveolar ventilation. By use of a shorter snorkel, the effective anatomical dead space will decrease and will cause a maximum rise in alveolar ventilation along with doubling of tidal volume.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 144
Incorrect
-
Electrophoresis is used to detect antibodies (immunoglobulins) in a blood sample from the umbilical artery of a new born. Which antibodies have the highest percentage in a new-born?
Your Answer:
Correct Answer: IgG
Explanation:IgG is a monomeric immunoglobulin. It is formed by two heavy chains and two light chains and has two binding sites. Its is the most abundant antibody that is equally distributed in the blood and the tissues. It is the only antibody that can pass through the placenta and thus the only antibody present in the baby after it is born. There are four subclasses: IgG1 (66%), IgG2 (23%), IgG3 (7%) and IgG4 (4%). IgG1, IgG3 and IgG4 cross the placenta easily
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This question is part of the following fields:
- General
- Physiology
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Question 145
Incorrect
-
What is formed when the ductus deferens unites with the duct of the seminal vesicle?
Your Answer:
Correct Answer: Ejaculatory duct
Explanation:The deferens is a cylindrical structure​ with dense walls and an extremely small lumen It is joined at an acute angle by the duct of the seminal vesicles to form the ejaculatory duct, which traverses the prostate behind it’s middle lobe and opens into the prostatic portion of the urethra, close to the orifice of the prostatic utricle.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 146
Incorrect
-
A growing tumour is impinging on the lingual artery in the floor of the mouth. Which structure will experience decreased blood flow?
Your Answer:
Correct Answer: The sublingual gland
Explanation:The paired sublingual glands are major salivary glands in the mouth. They are the smallest, most diffuse, and the only unencapsulated major salivary glands. They provide only 3-5% of the total salivary volume. The gland receives its blood supply from the sublingual and submental arteries. The sublingual artery is a branch of the lingual artery, thus damage to the lingual artery will decrease the blood flow to the sublingual gland.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 147
Incorrect
-
The renal tubule is the portion of the nephron that contains the fluid that has been filtered by the glomerulus. Which of the following substances is actively secreted into the renal tubules?
Your Answer:
Correct Answer: Potassium
Explanation:The renal corpuscle filters out solutes from the blood, delivering water and small solutes to the renal tubule for modification. In normal circumstances more than 90% of the filtered load of K is reabsorbed by the proximal tubules and loops of Henlé and almost all K appearing in the urine has been secreted by the late distal tubules and collecting tubules. So the rate of excretion is usually independent of the rate of filtration, but is closely tied to the rate of secretion and control of K excretion, largely accomplished by control of the secretion rate. Around 65–70% of the filtered potassium is reabsorbed along with water in the proximal tubule and the concentration of potassium in the tubular fluid varies little from that of the plasma.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 148
Incorrect
-
When a patient is standing erect, pleural fluid would tend to accumulate in which part of the pleural space?
Your Answer:
Correct Answer: Costodiaphragmatic recess
Explanation:The costo-diaphragmatic recess is the lowest extent of the pleural cavity or sac. Any fluid in the pleura will by gravity accumulate here when a patient is standing erect.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 149
Incorrect
-
A man in his sixties underwent surgery to remove a lump from his axilla. During removal, a nerve originating from the lateral cord of the brachial plexus was damaged. Which nerve is this referring to?
Your Answer:
Correct Answer: Lateral pectoral
Explanation:The only branch of the lateral cord of brachial plexus in the options given, is the lateral pectoral nerve. It supplies the pectoralis major muscle and sends a branch to join the medial pectoral nerve forming a loop in front of the first part of the axillary artery.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 150
Incorrect
-
Raised alkaline phosphatase and positive antimitochondrial antibody indicates which of the following conditions presenting with pruritus?
Your Answer:
Correct Answer: Primary biliary cirrhosis
Explanation:An autoimmune disease, primary biliary cirrhosis results in destruction of intrahepatic bile ducts. This leads to cholestasis, cirrhosis and eventually, hepatic failure. Symptoms includes fatigue, pruritus and steatorrhea. Increased IgM levels, along with antimitochondrial antibodies are seen in the serum. Liver biopsy is diagnostic, and also aids in staging of disease.
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This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
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Question 151
Incorrect
-
A new-born was found to have an undeveloped spiral septum in the heart. This is characteristic of which of the following?
Your Answer:
Correct Answer: Persistent truncus arteriosus
Explanation:Persistent truncus arteriosus is a congenital heart disease that occurs when the primitive truncus does not divide into the pulmonary artery and aorta, resulting in a single arterial trunk. The spiral septum is created by fusion of a truncal septum and the aorticopulmonary spiral septum. Incomplete development of these septa results in incomplete separation of the common tube of the truncus arteriosus and the aorticopulmonary trunk.
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This question is part of the following fields:
- Cardiovascular
- Pathology
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Question 152
Incorrect
-
During an operation to repair an aortic coarctation in a neonate, a surgeon accidentally cuts the first aortic intercostal arteries as he mobilised the descending aorta. Which one of the following structure might be deprived of its primary source of blood supply following this injury?
Your Answer:
Correct Answer: Right bronchus
Explanation:The right bronchus is supplied by one right bronchial artery that may branch from one of the left bronchial arteries or from the right 3rd posterior intercostal artery (this is the first intercostal artery that arises from the aorta). Damage to this artery might stop blood supply to the main bronchus. Intercostal arteries that go to the first and the second interspaces originate from the highest intercostal artery such that blood supply to either of these spaces would not be interfered with.
The left bronchus receives blood from 2 left bronchial arteries which are direct branches from the descending aorta.
Fibrous pericardium is the sac that contains the heart. Its blood supply is not a major concern.
Visceral pericardium receives its blood supply from the coronary vessels.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 153
Incorrect
-
Which cells are most commonly seen in a granulomatous lesion that suggests an underlying chronic inflammation?
Your Answer:
Correct Answer: Lymphocytes
Explanation:Lymphocytes and monocytes are commonly and characteristically recognised in a case of chronic inflammation.
Eosinophils and neutrophils are seen with acute inflammation.
Mast cells release histamine in early inflammation.
Basophils are seen with allergies.
Plasma cells are seen with viral infection.
Platelets are not characteristic of any type of inflammation.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
-
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Question 154
Incorrect
-
The pterygoid plexus receives tributaries from which of the following veins?
Your Answer:
Correct Answer: Maxillary vein
Explanation:The pterygoid plexus of veins is the main venous component associated with the infratemporal fossa. It receives tributaries corresponding to the branches of the internal maxillary artery. This plexus communicates freely with the anterior facial vein; it also communicates with the cavernous sinus, by branches through the foramen of Vesalius, foramen ovale and foramen lacerum. The (internal) maxillary vein is a short trunk which accompanies the first part of the (internal) maxillary artery. It is formed by a confluence of the veins of the pterygoid plexus and passes backward between the sphenomandibular ligament and the neck of the mandible and unites with the temporal vein to form the posterior facial vein. It carries blood away from the infratemporal fossa.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 155
Incorrect
-
Epstein-Barr virus (EBV) is known to be a carcinogen for:
Your Answer:
Correct Answer: B-cell lymphoma
Explanation:EBV is known to be carcinogenic for B-cell lymphoma, nasopharyngel carcinoma and Hodgkin’s lymphoma.
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This question is part of the following fields:
- Microbiology; Neoplasia
- Pathology
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Question 156
Incorrect
-
Different portions of the renal tubule have varying degrees of water permeability. Which of the following renal sites is characterised by low water permeability under normal circumstances?
Your Answer:
Correct Answer: Thick ascending limb of the loop of Henlé
Explanation:Within the nephron of the kidney, the ascending limb of the loop of Henle is a segment of the loop of Henle downstream of the descending limb, after the sharp bend of the loop. Both the thin and the thick ascending limbs of the loop of Henlé have very low permeability to water. Since there are no regulatory mechanisms to alter its permeability, it remains poorly permeable to water under all circumstances. Sodium and chloride are transported out of the luminal fluid into the surrounding interstitial spaces, where they are reabsorbed. Water must remain behind because it is not reabsorbed, so the solute concentration becomes less and less (the luminal fluid becomes more dilute). This is one of the principal mechanisms (along with diminution of ADH secretion) for the production of a dilute, hypo-osmotic urine (water diuresis).
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This question is part of the following fields:
- Physiology
- Renal
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Question 157
Incorrect
-
A 4-year-old child was brought to a paediatrician for consult due to a palpable mass in his abdomen. The child has poor appetite and regularly complains of abdominal pain. The child was worked up and diagnosed with a tumour. What is the most likely diagnosis ?
Your Answer:
Correct Answer: Nephroblastoma
Explanation:Nephroblastoma is also known as Wilms’ tumour. It is a cancer of the kidneys that typically occurs in children. The median age of diagnose is approximately 3.5 years. With the current treatment, approximately 80-90% of children with Wilms’ tumour survive.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 158
Incorrect
-
Choose the most correct answer regarding the common peroneal nerve.
Your Answer:
Correct Answer: It gives rise to the nerve that supplies the anterior compartment leg muscles
Explanation:The common peroneal nerve divides beneath the peroneus longus muscle and gives off articular and lateral sural cutaneous nerves which supply muscular branches to the muscles of the anterior compartment of the leg which are the tibialis anterior, extensor digitorum, peroneus tertius and extensor hallucis longus.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 159
Incorrect
-
A 35 year old man presented to the surgical OPD with a lump on his right forearm which appeared 3 weeks ago and was tender on examination. He gave a history was being in a car accident with pieces of glass from the windshield piercing his forearm removed manually and on further elective surgery. Which of these cells are characteristically found during inflammation in this situation?
Your Answer:
Correct Answer: Giant cell
Explanation:A foreign body reaction Is characteristic of giant cells. Glass being the foreign object initiates an inflammatory response in this condition.
Mast cells are involved in allergic reactions.
Eosinophils are characteristic of a parasitic infection and allergic inflammatory process but are not due to foreign bodies.
Plasma cells are typical of chronic inflammation.
Lymphocytes are involved in viral infections.
Macrophages combine together to form giant cells.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 160
Incorrect
-
A 42-year old woman presents to the doctor with jaundice. Her investigations show conjugated hyperbilirubinemia, raised urine bilirubin levels and low urine urobilinogen levels. What is the likely cause of her jaundice?
Your Answer:
Correct Answer: Blockage of the common bile duct
Explanation:The description of the patient here fits the diagnosis of obstructive jaundice or cholestasis, which results in conjugated hyperbilirubinemia. Cholestasis occurs due to impairment of bile flow, which can be anywhere from the liver cell canaliculus to the ampulla of Vater. Causes can be divided into intrahepatic and extrahepatic.
– Intrahepatic causes include hepatitis, drug toxicity, alcoholic liver disease, primary biliary cirrhosis, cholestasis of pregnancy and metastatic cancer.
– Extrahepatic causes include common duct stone, pancreatic cancer, benign stricture of the common duct, ductal carcinoma, pancreatitis and sclerosing cholangitis.
There is absence of bile constituents in the intestine, which causes spillage in the systemic circulation. Symptoms include pale stools, dark urine, pruritus, malabsorption leading to steatorrhea and deficiency of fat-soluble vitamins. Chronic cases can result in osteoporosis or osteomalacia due to vitamin D deficiency and Ca2+ malabsorption. Cholesterol and phospholipid retention produces hyperlipidaemia despite fat malabsorption (although increased liver synthesis and decreased plasma esterification of cholesterol also contribute); triglyceride levels are largely unaffected. The lipids circulate as a unique, low-density lipoprotein called lipoprotein X.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 161
Incorrect
-
Calculate the stroke volume in a patient admitted for coronary bypass surgery, with the following parameters pre-operatively:
Oxygen consumption = 300 ml/min
Arterial oxygen content = 20 ml/100 ml blood
Pulmonary arterial oxygen content = 15 ml/100 ml blood and Heart rate = 100 beats/min.Your Answer:
Correct Answer: 60 ml
Explanation:By Fick’s principle, cardiac output can be calculated as follows: VO2 = CO × (CAO2– CVO2) where VO2= oxygen consumption, CO = cardiac output, CAO2 = arterial oxygen content and CvO2 = mixed venous oxygen content. Thus, in the given problem, 300 ml/min = CO × (20 – 15) ml/100 ml CO = 300 × 100/5 ml/min CO = 6000 ml/min. Also, cardiac output = stroke volume × heart rate. Thus, 6000 ml/min = stroke volume × 100 beats/min. Hence, stroke volume = 6000/100 ml/min which is 60 ml/min.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 162
Incorrect
-
A correct statement about the RECTUM:
Your Answer:
Correct Answer: It is an important anastomotic site for the portal and caval (systemic) venous systems
Explanation:The rectum is part of the gastrointestinal tract that is continuous above with the sigmoid colon and below with the anal canal. It contains both longitudinal and circular smooth muscles. These are supplied by the enteric nervous system. It is about 12 cm long. It has no sacculations comparable with those of the colon. It has three permanent transverse folds called the valves of Houston. The peritoneum is related to the upper two thirds of the rectum only whereas the lower part is not covered by peritoneum. It is supplied by the superior rectal (hemorrhoidal) branch of the inferior mesenteric artery and the median sacral artery that is a direct branch from the abdominal aorta. It is drained by veins that begin as a plexus that surround the anus. These veins form anastomoses with the portal system (portocaval anastomoses).
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 163
Incorrect
-
A 30 year old female suffered from mismatched transfusion induced haemolysis. Which substance will be raised in the plasma of this patient?
Your Answer:
Correct Answer: Bilirubin
Explanation:Bilirubin is a yellow pigment that is formed due to the break down of RBCs. Haemolysis results in haemoglobin that is broken down into a haem portion and globin which is converted into amino acids and used again. Haem is converted into unconjugated bilirubin in the macrophages and shunted to the liver. In the liver it is conjugated with glucuronic acid making it water soluble and thus excreted in the urine. Its normal levels are from 0.2-1 mg/dl. Increased bilirubin causes jaundice and yellowish discoloration of the skin.
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This question is part of the following fields:
- General
- Physiology
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Question 164
Incorrect
-
The transverse colon has two curvatures known as the colic flexures on each side of its lateral ends, the right and left. The left colic flexure found on the side of the descending colon is attached to an organ superiorly by a mesenteric ligament. Which organ is this?
Your Answer:
Correct Answer: Spleen
Explanation:The left colic flexure is the bend of the transverse colon as it continues to form the descending colon on the left upper quadrant. The spleen is located on the superior aspect of the left colic flexure. It is commonly referred to as the splenic flexure because of its relation o the spleen superiorly.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 165
Incorrect
-
Perforin are present in the granules of which cell?
Your Answer:
Correct Answer: Natural killer cell
Explanation:Perforins are characteristically found In the granules of CD8+ T cells and natural killer cells. They are cytolytic proteins that insert into the target plasma membrane forming a hole and resulting in lysis. They along with granzyme B induce apoptosis in the target cell.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 166
Incorrect
-
Which tumour marker is associated with medullary carcinoma of thyroid?
Your Answer:
Correct Answer: Calcitonin
Explanation:Medullary carcinoma of thyroid accounts for 3% of thyroid cancers. It arises from the parafollicular cells (C cells) of the thyroid gland that produce calcitonin. It is often familial and caused by mutation of ret proto-oncogene, but can occasionally be sporadic. The familial cases can also occur as part of MEN syndromes IIA and IIB. The high calcitonin leads to down-regulation of the receptors, which does not affect the calcium levels significantly. Medullary carcinoma of thyroid shows characteristic amyloid deposits that stain positively with Congo red. The initial presentation consists of an asymptomatic thyroid nodule. Many cases are diagnosed due to routine screening of relatives of patients with MEN IIA and IIB. Medullary carcinoma can also cause ectopic production of other hormones/peptides such as adrenocorticotrophic hormone, vasoactive intestinal polypeptide, kallikreins and serotonin.
Metastasis from medullary carcinoma spread via the lymphatics to cervical and mediastinal nodes, and can also affect the liver, lungs and bone. Diagnosis is by raised serum calcitonin levels. A provocative test with calcium (15 mg/kg intravenously over 4 hours) also aids in diagnosis by leading to excessive secretion of calcitonin. X-ray might also show dense, conglomerate calcification.
CA-125 is frequently elevated in ovarian carcinomas. CA 15-3 is often associated with breast carcinomas. Alpha-fetoprotein is seen raised in hepatomas and gonadal tumours. Elevated HCG is associated with normal pregnancies, gonadal tumours, and choriocarcinomas. Thyroglobulin is used for surveillance in papillary carcinoma of thyroid. CA 19-9 is used in the management of pancreatic cancer.
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This question is part of the following fields:
- Endocrine
- Pathology
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Question 167
Incorrect
-
What is the pH of freshly formed saliva at ultimate stimulation?
Your Answer:
Correct Answer: 8
Explanation:Saliva has four major components: mucus (lubricant), α-amylase (enzyme that initiates digestion of starch), lingual lipase (enzyme that begins fat digestion), and a slightly alkaline electrolyte solution for moistening food. As the secretion rate of saliva increases, its osmolality increases. Moreover, the pH changes from slightly acidic (at rest) to basic (pH 8) at ultimate stimulation. This occurs due to increase of HCO3-. Amylase and mucus also increase in concentration after stimulation.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 168
Incorrect
-
A 70-year-old man who was previously healthy develops a rapidly progressing neurological deficit. A MRI reveals a large, poorly defined mass with central necrosis in his left temporal lobe. What is the most likely diagnosis?
Your Answer:
Correct Answer: Glioblastoma multiforme
Explanation:Glioblastoma multiforme, or grade 4 astrocytoma, is the most common and aggressive primary brain tumour. They are formed by small areas of necrotising tissue surrounded by highly anaplastic cells. Most of them arise from the deep white matter of the brain and quickly infiltrate it, becoming very large before they are symptomatic. The most common symptom is progressive memory, personality or neurological deficit due to temporal and frontal lobe involvement. It is most common in men, and risk factors include: neurofibromatosis, tuberous sclerosis, Von Hippel-Lindau disease, Li-Fraumeni syndrome, and Turcot syndrome.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 169
Incorrect
-
A football player sustained an injury to his ankle. The wound went through the skin, subcutaneous tissue and flexor retinaculum. Which other structure passing under the retinaculum may be injured?
Your Answer:
Correct Answer: Tibial nerve
Explanation:The flexor retinaculum is immediately posterior to the medial malleolus. The structures that pass under the flexor retinaculum from anterior to posterior are: tendon of the tibialis posterior, flexor digitorum longus, posterior tibial artery (and vein), tibial nerve and tendon of flexor hallucis longus. The tibial nerve is the only one which lies behind the flexor retinaculum.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 170
Incorrect
-
Atrial septal defect (ASD) is most likely to be due to incomplete closure of which one of the following structures:
Your Answer:
Correct Answer: Foramen ovale
Explanation:Atrial septal defect is a congenital heart defect that results in a communication between the right and left atria of the heart and may involve the interatrial septum. It results from incomplete closure of the foramen ovale which is normally open during fetal life and closes just after birth.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 171
Incorrect
-
Calculate the cardiac stroke volume of a patient whose oxygen consumption (measured by analysis of mixed expired gas) is 300 ml/min, arterial O2 content is 20 ml/100 ml blood, pulmonary arterial O2 content is 15 ml/100 ml blood and heart rate is 60/min.
Your Answer:
Correct Answer: 100 ml
Explanation:By Fick’s principle, VO2 = Q × (CA (O2) − CV (O2)) where VO2 = O2 consumption, Q = cardiac output and CA(O2) and CV(O2) are arterial and mixed venous O2 content respectively. Thus, in the given problem, 300 ml O2/min = Q × (20−15) ml O2/100 ml. Thus, Q = 6000 ml blood/min. Then, we can calculate stroke volume by dividing the cardiac output with heart rate. Thus, stroke volume = 6000 ml/min divided by 60/min stroke volume = 100 ml.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 172
Incorrect
-
In the human body, veins often run a course parallel to the artery that has the same name. Which of the following listed veins doesn't run parallel to the artery of the same name?
Your Answer:
Correct Answer: Inferior mesenteric
Explanation:The inferior mesenteric artery and inferior mesenteric vein don’t run in tandem because the vein is part of the portal venous system-draining into the splenic vein which drains into the hepatic portal vein. The inferior mesenteric artery is a branch of the descending aorta at the level of L3. The inferior mesenteric vein and artery, however, drain the same region i.e. the descending and sigmoid colon and rectum.
Superior epigastric vessels course together and are the continuation of the internal thoracic artery and vein.
Superficial circumflex iliac vessels course together in the superficial fat of the abdominal wall.
Superior rectal vessels are the terminal ends of the inferior mesenteric vessels, located on the posterior surface of the rectum.
The ileocolic artery and vein are branches off the superior mesenteric vessels. Both course in the mesentery, supplying/draining the caecum, appendix, terminal portion of the ileum. The inferior epigastric vessels run together.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 173
Incorrect
-
The muscle which has an antagonistic action to the serratus anterior muscle and is one of the retractors of the scapula is the?
Your Answer:
Correct Answer: Rhomboid major
Explanation:Protraction is accomplished by the actions of the serratus anterior, pectoralis major, and pectoralis minor muscles. Retraction is accomplished by the actions of the trapezius, rhomboids, and latissimus dorsi muscles.
The rhomboid major arises from the second, third, fourth and fifth thoracic vertebrae. It is inserted into a narrow tendinous arch attached to the root of the spine of the scapula and the inferior angle. By its insertion in the inferior angle of the scapula, it acts on this angle and produces a slight rotation of the scapula on the side of the chest. It also retracts the scapula by working with the trapezius muscle.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 174
Incorrect
-
After a severe asthma attack, a 26-year-old woman is left in a markedly hypoxic state. In which of the following organs are the arterial beds most likely to be vasoconstricted due to the hypoxia?
Your Answer:
Correct Answer: Lungs
Explanation:Hypoxic pulmonary vasoconstriction is a local response to hypoxia resulting primarily from constriction of small muscular pulmonary arteries in response to reduced alveolar oxygen tension. This unique response of pulmonary arterioles results in a local adjustment of perfusion to ventilation. This means that if a bronchiole is obstructed, the lack of oxygen causes contraction of the pulmonary vascular smooth muscle in the corresponding area, shunting blood away from the hypoxic region to better-ventilated regions. The purpose of hypoxic pulmonary vasoconstriction is to distribute blood flow regionally to increase the overall efficiency of gas exchange between air and blood.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 175
Incorrect
-
A 40-year old gentleman, who is a known with ulcerative colitis, complains of recent-onset of itching and fatigue. On examination, his serum alkaline phosphatase level was found to be high. Barium radiography of the biliary tract showed a 'beaded' appearance. What is the likely diagnosis?
Your Answer:
Correct Answer: Sclerosing cholangitis
Explanation:Primary sclerosing cholangitis is characterised by patchy inflammation, fibrosis and strictures in intra- and extra-hepatic bile ducts. It is a chronic cholestatic condition with 80% patients having associated inflammatory bowel disease (likely to be ulcerative colitis). Symptoms include pruritus and fatigue. ERCP (endoscopic retrograde cholangiopancreatography) or MRCP (magnetic resonance cholangiopancreatography) are diagnostic. Disease can lead to complete obliteration of ducts, which can result in liver failure. Cholangiocarcinoma is also a recognised complication..
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This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
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Question 176
Incorrect
-
The patient who is diagnosed with bladder cancer asked his physician, what could have been the contributing factor in the development of his bladder cancer?
Your Answer:
Correct Answer: Smoking
Explanation:Tobacco smoking is the main known contributor to urinary bladder cancer. In most populations, smoking is associated with over half of bladder cancer cases in men and one-third of cases among women.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 177
Incorrect
-
Which of the following cells would be increased in a patient suffering from a hydatid cyst in the liver?
Your Answer:
Correct Answer: Eosinophils
Explanation:Eosinophils are granulocytes that respond to parasitic infections. They are also involved in allergy response and asthma. They contain granules which stain red with Romanowsky’s method and contain peroxidase, Rnase, Dnase, histamine, lipase and major basic proteins that are toxic to the parasite as well as the hosts tissue. They are about 1-5% of the total WBC population and persist in the blood for 6-12 hours.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 178
Incorrect
-
Which of the following muscles winds around the pterygoid hamulus?
Your Answer:
Correct Answer: Tensor veli palatini
Explanation:The tensor veli palatini tenses the soft palate and by doing so, assists the levator veli palatini in elevating the palate to occlude and prevent entry of food into the nasopharynx during swallowing. It arises by a flat lamella from the scaphoid fossa at the base of the medial pterygoid plate, from the spina angularis of the sphenoid and from the lateral wall of the cartilage of the auditory tube. Descending vertically between the medial pterygoid plate and the medial pterygoid muscle, it ends in a tendon which winds around the pterygoid hamulus, being retained in this situation by some of the fibres of origin of the medial pterygoid muscle. Between the tendon and the hamulus is a small bursa. The tendon then passes medialward and is inserted onto the palatine aponeurosis and the surface behind the transverse ridge on the horizontal part of the palatine bone.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 179
Incorrect
-
Which of the following causes the maximum increase in the secretion of antidiuretic hormone (ADH)?
Your Answer:
Correct Answer: Increased plasma osmolarity
Explanation:The most potent stimulus for ADH release is increased plasma osmolarity. Decreased plasma volume is a less potent stimulus in comparison. However, decrease blood volume and arterial pressure due to severe haemorrhage does lead to ADH secretion. Hypothalamic releasing factors do not control the release of posterior pituitary hormones ADH and oxytocin.
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This question is part of the following fields:
- Endocrinology
- Physiology
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Question 180
Incorrect
-
The Carpal tunnel does NOT contain:
Your Answer:
Correct Answer: Flexor carpi ulnaris
Explanation:The contents of the carpal tunnel include:
– Median nerve
– Flexor digitorum supervicialis
– Flexor digitorum profundus
– Flexor policis longus
– Flexor carpi radialis
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 181
Incorrect
-
A terrorist running away from the police was shot in the back. The bullet hit his left lung halfway between its apex and the diaphragmatic surface. Which part of the lung was most likely to be injured?
Your Answer:
Correct Answer: Inferior lobe
Explanation:The oblique fissure of the left lung is so sharp that the posterior surface of the left lung is mostly composed of the inferior lobe so that the point halfway between the apex and the diaphragmatic surface of the lung would result in injury to the inferior lobe.
The hilum is the point on the medial surface of the lung where the structures that form the root of the lung enter and leave the lung.
The lingual on the other hand is part of the superior lobe of the left lung and it is part of the anterior and superior sides of the lung.
The middle lobe is only found on the right lung.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 182
Incorrect
-
A patient is suspected to have Blastomyces dermatidis infection. The patient contracted the disease most likely through which port of entry?
Your Answer:
Correct Answer: Respiratory tract
Explanation:Blastomycosis disease is a fungal infection acquired through inhalation of the spores. It caused by the organism Blastomyces dermatitidis and manifests as a primary lung infection in about 70% of cases. The onset is relatively slow and symptoms are suggestive of pneumonia.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 183
Incorrect
-
A 46-year old lady presents with chief complaints of a large mass in the left breast. Histopathology of the mass revealed a stromal component with an epithelial component. What is the likely lesion?
Your Answer:
Correct Answer: Phyllodes tumour
Explanation:Phyllodes tumours are large, quickly growing tumours which arise from the periductal stroma of the breast. These are fibroepithelial tumours and account for less than 1% of breast cancers. These tumours can be benign, borderline or malignant based on the histology. The tumour usually affects adult women, mostly between the age of 40 to 50 years. It can be confused with fibroadenoma, which however affects much younger patients.
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This question is part of the following fields:
- Pathology
- Women's Health
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Question 184
Incorrect
-
Signals pass through neuromuscular junctions via the neurotransmitter acetylcholine. After release from the skeletal neuromuscular junction, acetylcholine:
Your Answer:
Correct Answer: Causes postsynaptic depolarisation
Explanation:Acetylcholine is released from the presynaptic membrane into the cleft where it binds to the ion gated channels on the post synaptic membrane, causing them to open. This results in sodium entering into the fibre and further depolarizing it, creating an action potential.
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This question is part of the following fields:
- General
- Physiology
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Question 185
Incorrect
-
A 7-year-old girl is given cephalexin to treat an infection and develops hives, with localised facial oedema. Which of the following conditions will cause localised oedema?
Your Answer:
Correct Answer: Angio-oedema
Explanation:Angio-oedema, is the rapid swelling of the skin, mucosa and submucosal tissues. The underlying mechanism typically involves histamine or bradykinin. The version related to histamine is to due an allergic reaction to agents such as insect bites, food, or medications. The version related to bradykinin may occur due to an inherited C1 esterase inhibitor deficiency, medications e.g. angiotensin converting enzyme inhibitors, or a lymphoproliferative disorder.
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This question is part of the following fields:
- Physiology
- Renal
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Question 186
Incorrect
-
Gram positive bacteria differ from gram negative bacteria due to the presence of which of the following structures?
Your Answer:
Correct Answer: Outer membrane
Explanation:The reason bacteria are either Gram-positive or Gram-negative is due to the structure of their cell envelope (the cell envelope is defined as the cell membrane and cell wall plus an outer membrane, if one is present.) Gram-positive bacteria, for example, retain the crystal violet due to the amount of peptidoglycan in the cell wall. It can be said therefore that the Gram-stain procedure separates bacteria into two broad categories based on structural differences in the cell envelope.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 187
Incorrect
-
A 70-year-old male who has smoked since his teens complains of progressive shortness of breath and a persistent cough. He is diagnosed with COPD. Which of the following abnormalities is most likely to be present in his pulmonary function tests?
Your Answer:
Correct Answer: Increased residual volume
Explanation:Chronic obstructive pulmonary disease (COPD) is a type of obstructive lung disease characterized by long-term poor airflow. The main symptoms include shortness of breath and cough with sputum production. The best diagnostic test for evaluating patients with suspected chronic obstructive pulmonary disease (COPD) is lung function measured with spirometry. Key spirometrical measures may be obtained with a portable office spirometer and should include forced vital capacity (FVC) and the normal forced expiratory volume in the first second of expiration (FEV1). The ratio of FEV1 to forced vital capacity (FEV1/FVC) normally exceeds 0.75. Patients with COPD typically present with obstructive airflow. Complete pulmonary function testing may show increased total lung capacity, functional residual capacity and residual volume. A substantial loss of lung surface area available for effective oxygen exchange causes diminished carbon monoxide diffusion in the lung (DLco) in patients with emphysema. Tobacco smoking is the most common cause of COPD, with factors such as air pollution and genetics playing a smaller role.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 188
Incorrect
-
Which of the following diseases affects young adults, causing pain in any bone -particularly long bones- which worsens at night, and is typically relieved by common analgesics, such as aspirin?
Your Answer:
Correct Answer: Osteoid osteoma
Explanation:Osteoid osteoma, which tends to affect young adults, can occur in any bone but is most common in long bones. It can cause pain (usually worse at night) that is typically relieved by mild analgesics, such as non-steroidal anti-inflammatory drugs. X-ray findings include a small radiolucent zone surrounded by a larger sclerotic zone.
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This question is part of the following fields:
- Orthopaedics
- Pathology
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Question 189
Incorrect
-
The principal motor and sensory nerve of the perineum is the?
Your Answer:
Correct Answer: Pudendal
Explanation:The pudendal nerve is formed by S1,2,4 anterior branches. It gives off the inferior haemorrhoid nerve before dividing terminally into the perineal nerve and the dorsal nerve of the clitoris or the penis. Thus, it is the principal motor and sensory nerve of the perineum.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 190
Incorrect
-
A 25-year old man presented to the clinic with swelling of the penis. His uncircumcised penis was erythematous and oedematous. The foreskin could not be retracted over the glans. Which of the following agents is the likely cause of his condition?
Your Answer:
Correct Answer: Staphylococcus aureus
Explanation:Inflammation of the glans penis is known as balanitis. Associated involvement of the foreskin is then known as balanoposthitis. More likely to occur in men who have a tight foreskin that is difficult to pull back, or poor hygiene.
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This question is part of the following fields:
- Pathology
- Urology
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Question 191
Incorrect
-
Out of the following options, which malignancy has the highest potential for multicentricity?
Your Answer:
Correct Answer: Transitional cell carcinoma
Explanation:Transitional cell carcinomas can arise anywhere in the urothelium lining the urinary tract; and hence are known to be multicentric and recur commonly. Prostatic adenocarcinoma most commonly involves the posterior lobe of the prostate gland. Although renal cell carcinomas occasionally show multicentricity, it is not common. Penile carcinomas are usually locally infiltrative lesions. Wilm’s tumours are usually solitary, but can be bilateral or multicentric in 10% cases. Small cell carcinoma of lung and teratomas are usually solitary.
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This question is part of the following fields:
- Pathology
- Renal
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Question 192
Incorrect
-
A 20-year old involved in a brawl was stabbed in the anterior chest in a structure that is in close proximity to where the first rib articulates with the sternum. What is the structure that was most likely injured?
Your Answer:
Correct Answer: Sternoclavicular joint
Explanation:The first rib articulates with the sternum right below the sternoclavicular joint.
The sternal angle articulates with the costal cartilage of the second rib.
The nipple is found between the fourth and the fifth ribs, in the fourth intercostal space.
The xiphoid process is located right below the point of articulation of the costal cartilage of rib 7 with the sternum.
The root of the lung is the part of the lung where neurovascular structures enter and leave the lung.
Acromioclavicular joint is the point of articulation between the acromion process and the clavicle, near the shoulder.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 193
Incorrect
-
Which of the following is a likely consequence of severe diarrhoea?
Your Answer:
Correct Answer: A decrease in the sodium content of the body
Explanation:Diarrhoea can occur due to any of the numerous aetiologies, which include infectious, drug-induced, food related, surgical, inflammatory, transit-related or malabsorption. Four mechanisms have been implicated in diarrhoea: increased osmotic load, increased secretion, inflammation and decreased absorption time. Diarrhoea can result in fluid loss with consequent dehydration, electrolyte loss (Na+, K+, Mg2+, Cl–) and even vascular collapse. Loss of bicarbonate ions can lead to a metabolic acidosis.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 194
Incorrect
-
Passing through the lesser sciatic foramen are the:
Your Answer:
Correct Answer: Pudendal nerve
Explanation:Structures that pass through the lesser sciatic foramen include:
– the pudendal nerve
– the nerve to obturator internus
– internal pudendal artery
– the tendon of obturator internus
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 195
Incorrect
-
Into which vein does the left and right inferior thyroid veins drain?
Your Answer:
Correct Answer: Brachiocephalic vein
Explanation:The brachiocephalic vein is formed by the confluence of the subclavian and internal jugular veins. In addition it receives drainage from: the left and right internal thoracic veins (also called internal mammary veins), left and right inferior thyroid veins and the left superior intercostal vein.
The superior thyroid veins and middle thyroid veins drain into the internal jugular vein. The right and left inferior thyroid veins to drain into their respective brachiocephalic veins (right and left). -
This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 196
Incorrect
-
A 38-year-old woman with end-stage renal disease, is undergoing haemodialysis. She has normocytic normochromic anaemia. What is the best treatment for her?
Your Answer:
Correct Answer: Erythropoietin
Explanation:E erythropoietin (EPO) is a hormone that is released by the kidney. It is responsible for the regulation of red blood cell production in the body. It can be made using recombinant technology and is used in the treatment of anaemia of chronic renal failure and in patients under going chemotherapy
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This question is part of the following fields:
- General
- Physiology
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Question 197
Incorrect
-
A 40-year old man sustained a deep laceration to the sole of his left foot. It was found that the belly of extensor digitorum muscle was lacerated and the lateral tarsal artery was severed. The lateral tarsal artery is a branch of the:
Your Answer:
Correct Answer: Dorsalis pedis artery
Explanation:The lateral tarsal artery arises from the dorsalis pedis, as the vessel crosses the navicular bone
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 198
Incorrect
-
The basilar artery arises from the confluence of which two arteries?
Your Answer:
Correct Answer: Vertebral
Explanation:The basilar artery is part of the vertebrobasilar system. It is formed by the confluence of the two vertebral arteries which arise from the subclavian arteries. These two vertebral arteries merge at the level of cranial nerve VI at the junction between the pons and the medulla oblangata to form what is know as the basilar artery. This vertebrobasilar system supplies the upper spinal cord, brainstem, cerebellum, and posterior part of brain.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 199
Incorrect
-
Which organ is most vulnerable to haemorrhagic shock?
Your Answer:
Correct Answer: Kidneys
Explanation:At rest, the brain receives 15% cardiac output, muscles 15%, gastrointestinal tract 30% and kidneys receive 20%. However, if normalised by weight, the largest specific blood flow is received by the kidneys at rest (400 ml/min x 100g), making them highly vulnerable in the case of a haemorrhagic shock.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 200
Incorrect
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Which type of thyroid tumour represents 75 - 80% of thyroid cancer cases? This type is predominant in children and in patients who have had a previous history of head or neck radiation.
Your Answer:
Correct Answer: Papillary carcinoma
Explanation:Papillary thyroid carcinoma is the most common thyroid cancer. This cancer has a high cure rate with 10-year survival rates for all patients with papillary thyroid cancer estimated at 80% to 90%.
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This question is part of the following fields:
- Neoplasia
- Pathology
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