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Question 1
Incorrect
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The pterygoid plexus receives tributaries from which of the following veins?
Your Answer: Superficial temporal vein
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 2
Incorrect
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the action of the semimembranosus muscle is:
Your Answer: Flexion of the hip and flexion of the knee
Correct Answer: Extension of the hip and flexion of the knee
Explanation:the semimembranosus is situated at the back and medial side of the thigh. It arises from the upper and outer impression on the tuberosity of the ischium, above and lateral to the biceps femoris and semitendinosus. It is inserted mainly into the horizontal groove on the posterior medial aspect of the medial condyle of the tibia. it flexes the knee and assists in extension of the hip.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 3
Correct
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An 80 year-old lady presents to the out patient clinic complaining of chest pain of 2 months' duration with a normal electrocardiogram and cardiac enzymes. A computed tomographic scan is done which reveals a mass lesion involving a structure in the middle mediastinum. Which among the following structures could be involved?
Your Answer: Ascending aorta
Explanation:The middle mediastinum is the broadest part of the mediastinal cavity containing the heart enclosed in the pericardium, ascending aorta, lower half of the superior vena cava with the azygos vein opening into it, the bifurcation of the trachea and the two bronchi, the pulmonary artery with its branches, pulmonary veins, phrenic nerves and bronchial lymph nodes. The most likely structure involved is the ascending aorta, perhaps with an aneurysm.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 4
Correct
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An old man presented with atrophy of the thenar eminence despite the sensation over it still being intact. What is the injured nerve in this case?
Your Answer: Median nerve
Explanation:Atrophy of the thenar muscles means injury to the motor supply of these muscles. The nerve that sends innervation to it is the median nerve. But the median nerve does not provide sensory innervation to the overlying skin so sensation is spared.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 5
Correct
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A 45-year-old man presents to the emergency department with an irregular pulse and shortness of breath. Electrocardiography findings show no P waves, normal QRS complexes and an irregularly irregular rhythm. The patient most probably has:
Your Answer: Atrial fibrillation
Explanation:Atrial fibrillation is one of the most common arrhythmias, characterised by an irregular and rapid heart rate. Due to the decreased cardiac output, atrial fibrillation increases the risk of heart failure. It can also lead to thrombus formation which may lead to thromboembolic events. Clinical findings include palpitations, shortness of breath, fatigue, chest pain and confusion. The diagnosis is made by electrocardiographic findings which include absent P wave, fibrillatory (f) waves between QRS complexes and irregularly irregular R-R intervals.
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This question is part of the following fields:
- Cardiovascular
- Pathology
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Question 6
Incorrect
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Which of the following muscles are involved in abduction of the wrist?
Your Answer: Pronator teres and brachioradialis
Correct Answer: Extensor carpi radialis brevis and flexor carpi radialis
Explanation:The muscle of the wrist that cause abduction of the wrist otherwise also know as radial flexion of the wrist are the following:
-Abductor Pollicis Longus
-Flexor Carpi Radialis
-Extensor Carpi Radialis Longus
-Extensor Carpi Radialis Brevis
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 7
Correct
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Which of the following structures, is the area in which the superior cerebral veins drain into?
Your Answer: Superior sagittal sinus
Explanation:The superior cerebral veins are predominantly located on the superior aspect of the brain. They are 8 to 12 in number and they drain the lateral, medial and superior aspects of the cerebral hemispheres.
These veins drain into the superior sagittal sinus, also known as the superior longitudinal sinus – which is located along the attached margin of the falx cerebri.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 8
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 9
Correct
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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: 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 10
Correct
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A blood sample from a patient with polycythaemia vera will show which of the following abnormalities?
Your Answer: High platelet count
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 a myeloproliferative syndrome, 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 increased 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 11
Incorrect
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A 51-year old woman after undergoing a barium swallowing was discovered to be suffering from an oesophageal hiatal hernia. Which muscle fibres of the diaphragm border this hernia directly if the stomach herniates through an enlarged oesophageal hiatus?
Your Answer: Left crus
Correct Answer: Right crus
Explanation:The oesophageal hiatus is a natural fissure on the thoracic diaphragm that allows passage of the oesophagus and the vagal nerve. The oesophageal hiatus is located in one of the tendinous structures of the diaphragm that connect it to the spine which is known as the right crus. In case of an hiatal hernia, this diaphragmatic structure would be the one bordering the hernia as it is the structure that encircles the oesophageal hiatus.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 12
Correct
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Which of the following tumours has the best prognosis following surgery?
Your 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 13
Correct
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A 15-year-old girl was diagnosed with bacterial meningitis. Gram staining of the spinal fluid shows numerous polymorphonuclear neutrophils and Gram-positive cocci. Which is the empiric drug of choice to be given to the patient until the antibiotic sensitivity report is available?
Your Answer: Ceftriaxone
Explanation:Acute meningitis is a medical emergency. All suspects should receive their first dose of antibiotics immediately and be transferred to hospital as soon as possible. If facilities for blood culture and/or lumbar puncture (LP) are immediately available, they should be performed before administration
of the first dose of antibiotics (see contraindications to LP below). Neither procedure should lead to a significant delay in antibiotic administration.
Administer ceftriaxone 80-100 mg/kg (maximum 2 g, 12 hourly) intravenously. The intramuscular or intraosseous route can be used if there is no vascular access. Penicillin allergy is not a contraindication to ceftriaxone in acute meningitis (C-1). Omit ceftriaxone only if there has been documented ceftriaxone anaphylaxis. Give chloramphenicol 25 mg/kg (maximum 500 mg) intravenously instead, if available. Administer adequate analgesia and transfer the patient immediately to hospital, detailing all administered
medication in the referral letter. -
This question is part of the following fields:
- Microbiology
- Pathology
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Question 14
Incorrect
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A 58-year-old woman presents with signs of inflammation in the first metatarsophalangeal joint: redness, swelling and pain. The analysis of synovial fluid reveals needle-shaped, strongly negatively birefringent crystals. What's the most likely diagnosis in this case?
Your Answer: Pseudogout
Correct Answer: Gout
Explanation:Gout is a rheumatic disease caused by the precipitation of monosodium urate crystals into tissues, usually joints. This causes acute or chronic pain; the acute illness initially affects only one joint, often the first metatarsophalangeal joint. The diagnosis of the disease requires the identification of crystal in the synovial fluid. These crystals are needle-shaped and strongly negatively birefringent.
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This question is part of the following fields:
- Orthopaedics
- Pathology
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Question 15
Correct
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A lesion involving the suprachiasmatic nucleus of hypothalamus is likely to affect:
Your Answer: Regulation of circadian rhythm
Explanation:The suprachiasmatic nucleus (SCN) in the hypothalamus is responsible for controlling endogenous circadian rhythms and destruction of the SCN leads to a loss of circadian rhythm.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 16
Incorrect
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Blood investigations of a patient with vitamin K deficiency revealed a prolonged prothrombin time. This coagulation abnormality is most probably due to:
Your Answer: Abnormal fibrinolysis
Correct Answer: Factor VII deficiency
Explanation:Factor VII deficiency is a bleeding disorder caused by a deficiency or reduced activity of clotting factor VII. It may be inherited or acquired at some point during life. Inherited factor VII deficiency is an autosomal recessive disorder caused by mutations of the F7 gene. Factor VII is vitamin K-dependent, as are Factors II, IX and X and therefore lack of this vitamin can cause the development of acquired factor VII deficiency. Other causes of acquired deficiency of this factor include liver disease, sepsis and warfarin therapy.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 17
Incorrect
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Which of the following tumours is very radiosensitive?
Your Answer: Ovarian malignancy
Correct Answer: Seminoma
Explanation:Seminoma is the most radiosensitive tumour and responds well to radiation therapy after unilateral orchidectomy. The ipsilateral inguinal areas are routinely not treated however, depending on the stage, the mediastinum and the left supraclavicular regions may also be irradiated.
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This question is part of the following fields:
- Neoplasia; Urology
- Pathology
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Question 18
Incorrect
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A 45-year old man presents with sclerosing cholangitis, blood in his stools and apparent iron deficiency anaemia. What will be the most likely finding on his colonic biopsy?
Your Answer: Aphthous ulcers
Correct Answer: Pseudopolyps
Explanation:Sclerosing cholangitis along with the passage of blood in stools suggests ulcerative colitis affecting the mucosa and submucosa of rectum and colon, with a sharp demarcation with the normal tissue. The musclaris layer is involved in severe cases. Initially, the mucosa is erythematous, friable with scattered haemorrhagic areas and loss of normal vascular pattern. Severe disease is indicated by presence of large mucosal ulcers with purulent exudate. There can be islands of normal mucosa between the ulcerated mucosa, along with few hyperplastic inflammatory mucosal lesions (pseudopolyps). Ulcerative colitis does not lead to development of fistulas or abscesses.
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This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
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Question 19
Incorrect
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Hepatomegaly with greatly increased serum alpha-fetoprotein is seen in which of the following conditions?
Your Answer: Cholangiocarcinoma
Correct Answer: Hepatocellular carcinoma
Explanation:Hepatocellular carcinoma or hepatoma affects people with pre-existing cirrhosis and is more common in areas with higher prevalence of hepatitis B and C. Diagnosis include raise alpha-fetoprotein levels, imaging and liver biopsy if needed. Patients at high-risk for developing this disease can undergo screening by periodic AFP measurement and abdominal ultrasonography. The malignancy carries poor prognosis (see also Answer to 10.4).
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This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
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Question 20
Incorrect
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A new-born was found to have an undeveloped spiral septum in the heart. This is characteristic of which of the following?
Your Answer: Aortic valve stenosis
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 21
Incorrect
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What occurs during cellular atrophy?
Your Answer: Cell wall breakdown
Correct Answer: Cell size decreases
Explanation:Atrophy is the decrease in the size of cells, tissues, or organs. There are several causes including inadequate nutrition, poor circulation, loss of hormonal support or nerve supply, disuse, lack of exercise, or disease. An increase in cell size is termed hypertrophy which is distinguished from hyperplasia, in which the cells remain approximately the same size but increase in number.
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This question is part of the following fields:
- Cell Injury & Wound Healing; Urology
- Pathology
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Question 22
Correct
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Dysarthria, nystagmus and a tremor worsening with directed movement are likely to be seen in:
Your Answer: Cerebellar disease
Explanation:The given symptoms are seen in diseases affecting the cerebellum. A cerebellar tremor is a slow tremor that occurs at the end of a purposeful movement. It is seen in cerebellar disease, such as multiple sclerosis or some inherited degenerative disorders and chronic alcoholism. Classically, tremors are produced in the same side of the body as a one-sided lesion. Cerebellar disease can also result in a wing-beating’ type of tremor called rubral or Holmes’ tremor – a combination of rest, action and postural tremors. Other signs of cerebellar disease include dysarthria (speech problems), nystagmus (rapid, involuntary rolling of the eyes), gait problems and postural tremor of the trunk and neck.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 23
Incorrect
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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: CEA
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 24
Incorrect
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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: Factor VII
Correct 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 25
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 26
Incorrect
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The following joint has an anastomotic circulation that is provided by branches of the brachial artery:
Your Answer: Scapula
Correct Answer: Elbow joint
Explanation:The arterial anastomoses of the elbow joint is contributed by branches of the brachial artery and the Profunda brachii artery. The brachial artery gives off the superior ulnar collateral artery and the inferior collateral artery. On the other hand, the Profunda brachii gives off the radial and medial recurrent arteries.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 27
Incorrect
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What is the 5-year survival rate of carcinoma of the pancreas?
Your Answer: 5 per cent
Correct Answer: 30 per cent
Explanation:Pancreatic cancer typically has a poor prognosis, partly because the cancer usually initially remains symptomless, leading to locally advanced or metastatic disease at the time of diagnosis. Median survival from diagnosis is around 3–6 months. Even in those suitable for resectional surgery, 5-year survival rates are still only 30 per cent.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 28
Incorrect
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What forms the pelvic diaphragm?
Your Answer: Levator ani and piriformis muscles
Correct Answer: Levator ani and coccygeus muscles
Explanation:The pelvic diaphragm is formed by the levator ani and the coccygeus muscles. The levator ani forms the greater part of the pelvic floor supporting the viscera in the pelvic cavity.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 29
Correct
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A 54-year-old woman with amyotrophic lateral sclerosis is diagnosed with respiratory acidosis. The patient’s renal excretion of potassium would be expected to:
Your Answer: Fall, since tubular secretion of potassium is inversely coupled to acid secretion
Explanation:Respiratory acidosis is a medical emergency in which decreased ventilation (hypoventilation) increases the concentration of carbon dioxide in the blood and decreases the blood’s pH (a condition generally called acidosis). Secretion of acid and potassium by the renal tubule are inversely related. So, increased excretion of H+ during renal compensation for respiratory acidosis will result in decreased secretion (or increased retention) of potassium ions, with the result that the body’s potassium store rises. An increase in K+ excretion would be associated with renal compensation for respiratory alkalosis. The filtered load of K+depends only on K+ plasma concentration and glomerular filtration rate, not on plasma pH.
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This question is part of the following fields:
- Physiology
- Renal
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Question 30
Incorrect
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The vascular structure found on the right side of the fifth lumbar vertebra is?
Your Answer: Aorta
Correct Answer: Inferior vena cava
Explanation:The most likely vascular structure is the inferior vena cava. The inferior vena cava is formed by the joining of the two common iliac arteries, the right and the left iliac artery, at the level of the fifth lumbar vertebra( L5). The inferior vena cava passes along the right side of the vertebral column. It enters the thoracic cavity into the underside of the heart through the caval opening of the diaphragm at the level of the eight thoracic vertebra (T8).
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 31
Incorrect
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Which one of the following groups of lymph nodes is most likely to be inflamed due to paronychia involving the big toe?
Your Answer: Medial group of superficial inguinal lymph nodes
Correct Answer: Vertical group of superficial inguinal lymph nodes
Explanation:Paronychia affecting the big toe will result in inflammation of the superficial inguinal lymph nodes as it drains lymph from the big toe.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 32
Incorrect
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This structure divides the space between the lens and the cornea into the anterior and posterior chambers of the eye:
Your Answer: The pupil
Correct Answer: The iris
Explanation:The iris divides the space between the lens and the cornea into an anterior and a posterior chamber. The anterior cavity is filled with watery aqueous fluid, and the posterior cavity with a gel-like vitreous fluid. The anterior chamber of the eye is bounded in front by the posterior surface of the cornea; behind by the front of the iris and the central part of the lens. The posterior chamber is a narrow gap behind the peripheral part of the iris and in front of the suspensory ligament of the lens and the ciliary processes.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 33
Incorrect
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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) = 90 fl, mean corpuscular haemoglobin concentration (MCHC) = 41 g/dl. Further examination of blood sample revealed increased osmotic fragility of the erythrocytes. Which of the following is the most likely cause of this patient’s findings?
Your Answer: Iron-deficiency anaemia
Correct Answer: Spherocytosis
Explanation:Spherocytes are small rounded RBCs. It is due to an inherited defect of the RBC cytoskeleton membrane tethering proteins. Membrane blebs form that are lost over time and cells become round instead of biconcave. As it is a normochromic anaemia, the MCV is normal. it is diagnosed by osmotic fragility test which reveals increased fragility in a hypotonic solution.
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This question is part of the following fields:
- General
- Physiology
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Question 34
Incorrect
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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: Heparin is the treatment choice for DIC
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 35
Correct
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The renal cortex and medulla, if seen under the microscope, is lacking one of the following:
Your Answer: Squamous epithelium
Explanation:Capillaries, Henle’s loop, collecting ducts, Bertin columns and type IV collagen in glomerular basement membrane are all structures present in the renal cortex or medulla. The squamous epithelium is the only one that is lacking in both the renal cortex and medulla, because normally it is not found above the outer urethra.
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This question is part of the following fields:
- Pathology
- Renal
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Question 36
Incorrect
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Out of the following options, which malignancy has the highest potential for multicentricity?
Your Answer: Renal cell carcinoma
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 37
Incorrect
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Normally, the O2 transfer in the lungs from alveolar to capillary is perfusion-limited. In which of the following situations does it become a diffusion-limited process?
Your Answer: Mild exercise
Correct Answer: Pulmonary oedema
Explanation:Normally, the transfer of oxygen from air spaces to blood takes place across the alveolar-capillary membrane by simple diffusion and depends entirely on the amount of blood flow (perfusion-limited process). Diseases that affect this diffusion will transform the normal process to a diffusion limited process. Thus, the diseases which cause a thickened barrier (such as pulmonary oedema due to increased extravascular lung water or asbestosis) will limit the diffusion of oxygen. Chronic obstructive lung diseases will have little effect on diffusion. Inhaling hyperbaric gas mixtures might overcome the diffusion limitation in patients with mild asbestosis or interstitial oedema, by increasing the driving force. Strenuous (not mild) exercise might also favour diffusion limitation and decrease passage time. Increasing the rate of ventilation will not have this affect but will only maintain a high oxygen gradient from air to blood.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 38
Correct
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Signals pass through neuromuscular junctions via the neurotransmitter acetylcholine. After release from the skeletal neuromuscular junction, acetylcholine:
Your 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 39
Incorrect
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During a procedure in the mediastinum, the surgeon accidentally injured a key structure that lies immediately anterior to the thoracic duct. Which structure is likely to be injured?
Your Answer: Superior vena cava
Correct Answer: Oesophagus
Explanation:In the mid-thorax, the azygos vein, thoracic duct and aorta (in this order from right to the left) are all located posterior to the oesophagus. The superior vena cava, left internal jugular vein and trachea are not found in the mid thorax.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 40
Incorrect
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What is the linea aspera:
Your Answer: Is found on the inferior pubic ramus
Correct Answer: Serves as an attachment for adductors of the thigh
Explanation:The linea aspera is a prominent longitudinal ridge or crest on the middle third of the femur. It has a medial and a lateral lip and a narrow, rough, intermediate line. The vastus medialis arises from the medial lip of the linea aspera and has superior and inferior prolongations. The vastus lateralis takes origin from the lateral lip . The adductor magnus is inserted into the linea aspera. Two muscles are attached between the vastus lateralis and the adductor magnus: the gluteus maximus is inserted above and the short head of the biceps femoris arises below. Four muscles are inserted between the adductor magnus and the vastus medialis: the iliacus and pectineus superiorly, and the adductor brevis and adductor longus inferiorly.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 41
Incorrect
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A sexually active 21 year old man presents with the history of dysuria for the past 3 days. Urine culture confirmed Neisseria gonorrhoeae and smear showed abundant neutrophils. Which of the following mediators is responsible for causing diapedesis of the neutrophils to reach the site of infection?
Your Answer: Bradykinin
Correct Answer: Complement C5a
Explanation:C5a is part of the complement cascade and is released frim the complement C5. It acts as a chemotactic factor for neutrophils. Other chemotactic mediators are TNF, leukotrienes and bacterial products.
Bradykinin is associated with the production of pain and vasodilation.
Hageman factor is a clotting factor.
Histamine causes vasodilation.
C3B causes opsonisation.
IL-6 and IL-12 are inflammatory mediators causing B cell maturation and mediating inflammation and prostaglandins are involved with pain, increasing cell permeability and vasodilation.
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This question is part of the following fields:
- Inflammation & Immunology; Urology
- Pathology
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Question 42
Incorrect
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Which of the following is a landmark to identify the site of the 2nd costal cartilage?
Your Answer: Sternal notch
Correct Answer: Sternal angle
Explanation:The sternal angle is an important part where the second costal cartilage attaches to the sternum. Finding the sternal angle will help in finding the second costal cartilage and intercostal space.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 43
Incorrect
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A 78-year-old woman was brought to the emergency department with decreased consciousness, weakness and dehydration. Which serum electrolyte would most likely be low in this patient?
Your Answer: Ca2+
Correct Answer: Na+
Explanation:Hyponatremia is a sodium level below 135 mEq/L. Signs and symptoms may include: nausea with vomiting, fatigue, headache or confusion, cramps or spasm, irritability and restlessness and severe cases may lead to seizures and comma.
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This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
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Question 44
Incorrect
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A 27-year old lady presented with dull, abdominal pain and some pain in her lower limbs. On enquiry, it was revealed that she has been suffering from depression for a few months. Physical examination and chest X-ray were normal. Further investigations revealed serum calcium 3.5 mmol/l, albumin 3.8 g/dl and phosphate 0.65 mmol/l. What is the diagnosis?
Your Answer: Pituitary adenoma
Correct Answer: Parathyroid adenoma
Explanation:Hypercalcaemia with hypophosphatemia indicates parathyroid disorder and adenomas are more common than hyperplasia. In this young age group, metastatic disease is unlikely. Solitary adenomas are responsible for 80-85% cases of primary hyperparathyroidism. 10-15% cases are due to parathyroid hyperplasia and carcinomas account for 2-3% cases. Symptoms include bone pain (bones), nephrolithiasis (stones), muscular aches, peptic ulcer disease, pancreatitis (groans), depression (moans), anxiety and other mental disturbances.
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This question is part of the following fields:
- Endocrine
- Pathology
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Question 45
Incorrect
-
A 25 year old women is pregnant with her second child. She is A- blood group. Her first child was Rh+ and the father is also Rh+. The second child is at a risk of developing which condition?
Your Answer: Drug-induced haemolytic anaemia
Correct Answer: Haemolytic disease of the new-born
Explanation:This infant is at risk for haemolytic disease of the new born also known as erythroblastosis fetalis. In the pregnancy, Rh-positive RBC’s cross the placenta and enter the mothers blood system. She then becomes sensitised and forms IgG antibodies/anti-Rh antibodies against them. The second child is at a greater risk for this disease than the first child with Rh-positive blood group as during the second pregnancy, a more powerful response is produced. IgG has the ability to cross the placenta and bind to the fetal RBCs (type II hypersensitivity reaction) which are phagocytosed by the macrophages.
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This question is part of the following fields:
- Inflammation & Immunology; Haematology
- Pathology
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Question 46
Incorrect
-
A 50 year old female patient with an history of chronic headache was scheduled for CT scan. If the CT scan revealed a tumour at the horn of the lateral ventricle, which of the following structures is most likely to be compressed by this tumour?
Your Answer: Thalamus
Correct Answer: Fibres of the corpus callosum
Explanation:The ventricular system of the brain is made up of four ventricles namely; two lateral and a third and forth ventricle. The ventricles are the site of the development of the cerebrospinal fluid. The left and right lateral ventricles are located in each of the brain’s hemispheres. The roof of the lateral ventricles are made up of the fibres of the corpus callosum. This is the structure that would be compressed by the a tumour on the roof of the lateral ventricles.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 47
Incorrect
-
T lymphocytes that express the MCH type II antigen are most likely to produce which of the following cytokines?
Your Answer: Alpha interferon
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 48
Incorrect
-
Gastrocnemius, semimembranosus and semitendinosus together with which other muscle form the boundaries of the popliteal fossa?
Your Answer: Gracilis
Correct Answer: Biceps femoris
Explanation:The popliteal fossa is located at the back of the knee. It is bounded laterally by the biceps femoris above and the plantaris and lateral head of the gastrocnemius below and medially by the semitendinosus and semimembranosus above and by the medial head of the gastrocnemius below.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 49
Correct
-
Atractyloside is an inhibitor of electron transport chain. It is expected to have little or no effect on the functioning of which of the following cell types?
Your Answer: Red blood cells
Explanation:Electron transport chain is a series of electron carriers that are embedded in the mitochondrial membrane. It is the place where ATP is made. Inhibiting the electron transport chain will stop production of ATP. Red blood cells are the only cell in the given option which do not contain ATP.
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This question is part of the following fields:
- General
- Physiology
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Question 50
Incorrect
-
A 63-year old lady presents with pain in multiple bones and renal failure. On enquiry, there is history of recurrent pneumonia in the past. What will be the likely finding on her bone marrow biopsy?
Your Answer: Granulomas
Correct Answer: Plasma cells
Explanation:Multiple myeloma is a plasma cell malignancy that produce excessive monoclonal immunoglobulins. The disease presents with bone pains, renal dysfunction, increased calcium, anaemia and recurrent infections. Diagnosis is by demonstrating the presence of M-protein in urine or serum, lytic bone lesions, light chain proteinuria or excessive plasma cells on marrow biopsy.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 51
Incorrect
-
In the kidney, the macula densa is an area of closely packed specialized cells lining the wall of the:
Your Answer: Afferent arteriole
Correct Answer: Distal convoluted tubule
Explanation:In the kidney, the macula densa is an area of closely packed specialised cells lining the region of the distal convoluted tubule (DCT) lying next to the glomerular vascular pole. The cells of the macula densa are sensitive to the ionic content and water volume of the fluid in the DCT, producing signals that promote renin secretion by other cells of the juxtaglomerular apparatus.
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This question is part of the following fields:
- Physiology
- Renal
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Question 52
Incorrect
-
The oesophagus is an important part of the alimentary canal. It receives blood from various arteries in the body. Which one of the following is an artery that will lead to some level of ischaemia to the oesophagus when ligated?
Your Answer: Right suprarenal
Correct Answer: Left inferior phrenic
Explanation:The oesophagus receives its blood supply from the following arteries: the inferior thyroid branch of the thyrocervical trunk, the descending thoracic aorta, the left gastric branch of the coeliac artery and the from the left inferior phrenic artery of the abdominal aorta. Hence ligation of the left inferior phrenic will lead to ischemia to some portions of the oesophagus.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 53
Incorrect
-
Leukotrienes normally function during an asthma attack and work to sustain inflammation. Which of the following enzymes would inhibit their synthesis?
Your Answer: Cyclooxygenase-1
Correct Answer: 5-lipoxygenase
Explanation:Leukotrienes are produced from arachidonic acid with the help of the enzyme 5-lipoxygenase. This takes place in the eosinophils, mast cells, neutrophils, monocytes and basophils. They are eicosanoid lipid mediators and take part in allergic and asthmatic attacks. They are both autocrine as well as paracrine signalling molecules to regulate the body’s response and include: LTA4, LTB4, LTC4, LTD4, LTE4 and LTF4.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 54
Incorrect
-
Which of the following is a fact worth noting about the development of the spleen?
Your Answer: The developing spleen in the embryo arises in week 1.
Correct Answer: It develops in the dorsal mesogastrium
Explanation:The spleen in the human embryo arises in week 5 of intrauterine life. It appears as a proliferating mesenchyme above the pancreas. The spleen is one the organs that develops in the dorsal mesogastrium. When the stomach changes its position during development, the spleen is made to move behind the stomach and stays in contact with the left kidney. The spleen is found within the peritoneum of the abdominal cavity thus it is an intraperitoneal organ.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 55
Incorrect
-
A 60-year old patient presenting with squamous cell carcinoma of the anal canal was brought in to the oncology ward for chemotherapy. In which of the following lymph nodes of this patient would you likely find metastases?
Your Answer: Lateral aortic
Correct Answer: Internal iliac
Explanation:The efferent lymphatics from the anal canal proceed to the internal iliac lymph nodes. This would most likely form the site of enlargement in the lymphatics.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 56
Incorrect
-
A 27 year-old male patient was admitted to the hospital due to recurrent fever for the past 2 weeks. The patient claimed that he is an intravenous drug user. Following work up, the patient was diagnosed with infective endocarditis. Which is the most likely organism responsible for this diagnosis?
Your Answer: Enterococcus
Correct Answer: Staphylococcus aureus
Explanation:Acute bacterial endocarditis is a fulminant illness lasting over days to weeks (<2weeks). It is most likely due to Staphylococcus aureus especially in intravenous drug abusers.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 57
Incorrect
-
An intern is attempting to put in an arterial line in an ICU patients left foot. Which is the best site to feel for the pulsation of the dorsalis pedis artery in the foot?
Your Answer: Behind the tendon of fibularis tertius muscle
Correct Answer: Just lateral to the tendon of extensor hallucis longus
Explanation:The dorsalis pedis artery is the continuation of the anterior tibial artery. The pulse of the posterior tibial artery, which comes from the posterior compartment of the leg, may be felt behind the medial malleolus just lateral to the tendon of the extensor hallucis longus.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 58
Incorrect
-
A patient is admitted to the ICU, and is prescribed tazobactam, amongst other drugs. What is the mechanism of action of tazobactam?
Your Answer: Inhibits CD3 receptor
Correct Answer: Inhibits beta-lactamase
Explanation:Tazobactam is a compound which inhibits the action of bacterial beta-lactamases. It is added to the extended-spectrum beta-lactam antibiotic piperacillin to broaden the spectrum of piperacillin by making it effective against organisms that express beta-lactamase and would normally degrade piperacillin.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 59
Incorrect
-
A 45-year old gentleman presents with diarrhoea for two weeks. He has no history of fever and the diarrhoea stops on fasting. Which is the most likely type of diarrhoea that he is suffering from?
Your Answer: Drug induced
Correct Answer: Osmotic
Explanation:The different types of diarrhoea are:
1. Secretory diarrhoea – Due to increased secretion or decreased absorption. There is minimal to no structural damage in this type. The most common cause is cholera toxin which stimulates secretion of anions (especially chloride), with sodium and water.
2. Osmotic diarrhoea – Due to increased osmotic load, there is water loss. This occurs in cases of maldigestion syndromes, such as coeliac or pancreatic disease.
3. Motility-related diarrhoea – Occurs in cases of abnormal gastrointestinal motility. Due to increased motility, there is poor absorption and this leads to diarrhoea. This is seen post-vagotomy or in diabetic neuropathy.
4. Inflammatory diarrhoea – Due to damage to the mucosa or brush border, there is a loss of protein-rich fluids and poor absorption. Features of all the above three types can be seen in this type. Aetiology includes bacterial, viral, parasitic infections or autoimmune problems including inflammatory bowel disease.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 60
Incorrect
-
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 61
Incorrect
-
A 38 year old man is to undergo excision of the base of the prostate for malignant growth, which of the following structures is directly related to the base of the prostate?
Your Answer: Rectum
Correct Answer: Urinary bladder
Explanation:The prostate is situated in the pelvic cavity and is also located immediately below the internal urethral orifice at the commencement of the urethra. It is held in position by the puboprostatic ligaments, the superior fascia of the urogenital diaphragm and the anterior portions of the levatores ani. The base of the prostate is directed upward and is attached to the inferior surface of the urinary bladder while the apex is directed downward and is in contact with the superior fascia of the urogenital diaphragm.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 62
Incorrect
-
A patient is diagnosed with Conn’s syndrome. Aldosterone is secreted from where?
Your Answer: Liver
Correct Answer: Zona glomerulosa of the adrenal cortex
Explanation:The adrenal gland comprises an outer cortex and an inner medulla, which represent two developmentally and functionally independent endocrine glands.
The adrenal medulla secretes adrenaline (70%) and noradrenaline (30%)
The adrenal cortex consists of three layers (remembered by the mnemonic GFR):
G = zona glomerulosa – secretes aldosterone
F = zona fasciculata – secretes cortisol and sex steroids
R = zona reticularis – secretes cortisol and sex steroids.
Aldosterone facilitates the reabsorption of sodium and water and the excretion of potassium and hydrogen ions from the distal convoluted tubule and collecting ducts. Conn’s syndrome is characterized by increased aldosterone secretion from the adrenal glands.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 63
Correct
-
When one is silently counting, what part of his brain will show increased regional cerebral blood flow (rCBF)?
Your 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 64
Correct
-
A 54-year-old woman is re-admitted to the hospital with shortness of breath and sharp chest pain 2 weeks after surgical cholecystectomy. The most probable cause of these clinical findings is:
Your Answer: Pulmonary embolus
Explanation:Pulmonary embolism is caused by the sudden blockage of a major lung blood vessel, usually by a blood clot. Symptoms include sudden sharp chest pain, cough, dyspnoea, palpitations, tachycardia or loss of consciousness. Risk factors for developing pulmonary embolism include long periods of inactivity, recent surgery, trauma, pregnancy, oral contraceptives, oestrogen replacement, malignancies and venous stasis.
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This question is part of the following fields:
- Pathology
- Respiratory
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Question 65
Incorrect
-
A 15 month old boy has a history of repeated bacterial pneumonia, failure to thrive and a sputum culture positive for H.influenzea and S.pneumoniae. There is no history of congenital anomalies. He is most likely suffering from?
Your Answer: Acute leukaemia
Correct Answer: X-linked agammaglobulinemia
Explanation:Recurrent bacterial infections may be due to lack of B-cell function, consequently resulting in a lack of gamma globulins production. Once the maternal antibodies have depleted, the disease manifests with greater severity and is called x-linked agammaglobulinemia also known as ‘X-linked hypogammaglobulinemia’, ‘XLA’ or ‘Bruton-type agammaglobulinemia. it is a rare x linked genetic disorder that compromises the bodies ability to fight infections.
Acute leukaemia causes immunodeficiency but not so specific.
DiGeorge syndrome is due to lack of T cell function.
Aplastic anaemia and EBV infection does not cause immunodeficiency.
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This question is part of the following fields:
- Inflammation & Immunology; Respiratory
- Pathology
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Question 66
Incorrect
-
During the fetal stage, the mesonephric tubules gives rise to the?
Your Answer: Appendix of testis
Correct Answer: Wolffian duct
Explanation:The development of the kidney proceeds through a series of successive phases, each marked by the development of a more advanced kidney: the pronephros, mesonephros, and metanephros. The development of the pronephric duct proceeds in a cranial-to-caudal direction. As it elongates caudally, the pronephric duct induces nearby intermediate mesoderm in the thoracolumbar area to become epithelial tubules called mesonephric tubules. Each mesonephric tubule receives a blood supply from a branch of the aorta, ending in a capillary tuft analogous to the glomerulus of the definitive nephron. The mesonephric tubule forms a capsule around the capillary tuft, allowing for filtration of blood. This filtrate flows through the mesonephric tubule and is drained into the continuation of the pronephric duct, now called the mesonephric duct or Wolffian duct. The nephrotomes of the pronephros degenerate while the mesonephric duct extends towards the most caudal end of the embryo, ultimately attaching to the cloaca.
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This question is part of the following fields:
- Anatomy
- Embryology
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Question 67
Incorrect
-
Internal haemorrhoids are painless and only sensitive to stretch. They are formed from folds of the mucous membrane and the submucosa of the anal canal which contain varicose branches of the:
Your Answer: Middle rectal artery
Correct Answer: Superior rectal vein
Explanation:Internal haemorrhoids are formed by varicosities of the branches of the superior rectal vein.
External haemorrhoids are formed by varicosities of the branches of the inferior rectal vein.
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This question is part of the following fields:
- Anatomy
- Colorectal
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Question 68
Incorrect
-
A 15-day old baby was brought to the emergency department with constipation for 4 days. On examination, the abdomen of the baby was found to be distended and tender all over. No bowel sounds were heard. A sigmoid colon biopsy was carried out, which showed absent ganglion cells. What is the diagnosis?
Your Answer: Chagas’ disease
Correct Answer: Hirschsprung’s disease
Explanation:Hirschsprung’s disease is characterized by congenital absence of the autonomic plexus (Meissner’s and Auerbach’s plexus) in the intestinal wall. Usually limited to the distal colon, it can occasionally involve the entire colon or even the small bowel. There is abnormal or absent peristalsis in the affected segment, resulting in continuous spasm of smooth muscle and partial/complete obstruction. This causes accumulation of intestinal contents and dilatation of proximal segment. Skip lesions are highly uncommon. This disease is seen early in life with 15% patients presenting in first month, 60% by 1 year of age and 85% by the age of 4 years. Symptoms include severe and complete constipation, abdominal distension and vomiting. Patients with involvement of ultra-short segments might have mild constipation with intervening diarrhoea. In older children, symptoms include failure to thrive, anorexia, and lack of an urge to defecate. On examination, an empty rectum is revealed with stool palpable high up in the colon. If not diagnosed in time, it can lead to Hirschsprung’s enterocolitis (toxic megacolon), which can be fulminant and lead to death. Diagnosis involves a barium enema or a rectal suction biopsy. Barium enema shows a transition in diameter between the dilated, normal colon proximal to the narrowed, affected distal segment. It is to be noted that barium enema should be done without prior preparation, which can dilate the abnormal segment, leading to a false-negative result. A 24-hour post-evacuation film can be obtained in the neonatal period – if the colon is still filled with barium, there is a high likelihood of Hirschsprung’s disease. Full-thickness rectal biopsy is diagnostic by showing the absence of ganglion cells. Acetylcholinesterase staining can be done to highlight the enlarged nerve trunks. Abnormal innervation can also be demonstrated by rectal manometry.
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This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
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Question 69
Incorrect
-
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: Middle scalene
Correct 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 70
Incorrect
-
A 78-year-old diabetic man undergoes renal function tests. Which of the following substances will be the most accurate for measuring glomerular filtration rate (GFR)?
Your Answer: Glucose
Correct Answer: Inulin
Explanation:Glomerular filtration rate (GFR) is the volume of fluid filtered from the renal glomerular capillaries into the Bowman’s capsule per unit time. Clinically, this is often measured to determine renal function. Inulin was originally used as it is not reabsorbed by the kidney after glomerular filtration, therefore its rate of excretion is directly proportional to the rate of filtration of water and solutes across the glomerular filter. However, in clinical practice, creatinine clearance is used to measure GFR. Creatinine is an endogenous molecule, synthesised in the body, that is freely filtered by the glomerulus (but also secreted by the renal tubules in very small amounts). Creatinine clearance exceeds GFR due to creatinine secretion, and is therefore a close approximation of the GFR.
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This question is part of the following fields:
- Physiology
- Renal
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Question 71
Correct
-
What intrinsic muscle of the larynx is responsible for the tensing of the vocal cords?
Your Answer: Cricothyroid muscle
Explanation:The cricothyroid muscle is the only tensor muscle of the larynx aiding with phonation. It attaches to the anterolateral aspect of the cricoid and the inferior cornu and lower lamina of the thyroid cartilage. Its action tilts the thyroid forward to help tense the vocal cords.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 72
Correct
-
The rotator cuff surrounds the shoulder joint and consists of the supraspinatus, infraspinatus, subscapularis and which one other muscle?
Your Answer: Teres minor
Explanation:The correct answer is the teres minor muscle. These group of muscles play an important role in protecting the shoulder joint and keeping the head of the humerus in the glenoid fossa of the scapula. This fossa is somehow shallow and needs support to allow for the full mobility that the shoulder joint has.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 73
Incorrect
-
A 42 - year old male patient with an acute onset headache was brought in to the emergency department with suspicion of a subarachnoid haemorrhage (SAH). The SHO on call decided to have a diagnostic lumbar puncture after computed topography scan failed to support the suspicion. To perform a successful lumbar puncture without causing injury to the spine, which anatomical landmark should guide the SHO to locate the fourth vertebra for insertion of the spinal needle?
Your Answer: Coccyx
Correct Answer: Iliac crest
Explanation:The safest spinal level for conducting a lumbar puncture, is at the level of the fourth lumbar vertebra. The anatomical landmark used to locate the fourth lumbar vertebra (L4), is the iliac crest. The needle can safely be inserted either above or below L4. The conus medullaris is at the level of the border of L1 and L2 so L4 is safely distant from it.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 74
Incorrect
-
A 35 year-old female developed food poisoning 24H after eating canned food. She complained of abdominal cramps, with nausea and vomiting. Shortly after she suddenly developed weakness, blurring of vision, difficulty in swallowing and breathing. Which of the following organisms is most likely associated with fatal food poisoning?
Your Answer: Vibrio cholerae
Correct Answer: Clostridium botulinum
Explanation:C. botulinum is a Gram-positive, rod-shaped, spore-forming bacterium. It is an obligate anaerobe, meaning that oxygen is poisonous to the cells. Only botulinum toxin types A, B, E, and F cause disease in humans. Types A, B, and E are associated with foodborne illness. Botulism poisoning can occur due to preserved or home-canned, low-acid food that was not processed using correct preservation times and/or pressure. Signs and symptoms of foodborne botulism typically begin between 18 and 36 hours after the toxin gets into the body, but can range from a few hours to several days, depending on the amount of toxin ingested. Botulinum that is produced by Clostridium botulinum can cause respiratory and muscular paralysis.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 75
Incorrect
-
Which of the following has the highest content of triglycerides?
Your Answer: HDL
Correct Answer: Chylomicron
Explanation:Created by the small intestinal cells, chylomicrons are large lipoprotein molecules which transport lipids to the liver, adipose, cardiac and skeletal tissue. Chylomicrons are mainly composed of triglycerides (,85%) along with some cholesterol and cholesteryl esters. Apo B-48 is the main apolipoprotein content.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 76
Incorrect
-
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 77
Incorrect
-
An electronic manufacturing engineer had abdominal distension and underwent a CT scan of the abdomen. Thereafter he was diagnosed with hepatic angiosarcoma. Exposure to what agent is responsible for the development of this neoplasm?
Your Answer: Dust particles
Correct Answer: Arsenic
Explanation:Hepatic angiosarcomas are associated with particular carcinogens which includes: arsenic , thorotrast, and polyvinyl chloride. With exposure to this three agents, there is a very long latent period of many years between exposure and the development of tumours.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 78
Incorrect
-
The Brunner glands secrete an alkaline product that helps maintain an optimal pH for pancreatic enzyme activity. Where are these glands located?
Your Answer: At the base of the villi throughout the small intestine
Correct Answer: Submucosa of the duodeneum
Explanation:The Brunner glands are located in the submucosa of the duodenum. These glands are connected to the interstitial lumen by ducts that open into certain crypts. They secrete an alkaline product that protects the duodenal mucosa from the acidic chyme and helps achieve an optimal pH for the enzymes.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 79
Incorrect
-
Which of these is secreted by both macrophages and muscle cells?
Your Answer: Interleukin 1
Correct Answer: Interleukin-6
Explanation:IL-6 is secreted by the T cells and macrophages and is a pro inflammatory cytokine. It is secreted in response to trauma e.g. burns and tissue damage that leads to inflammation. Apart from this its is also a myokine and is elevated due to muscle contraction. Other functions include: stimulate osteoclast formation when secreted by osteoblasts, mediate fever in acute phase response and are responsible for energy metabolism in muscle and fatty tissues. Inhibitors of IL-6 e.g. oestrogen are used as a treatment for postmenopausal osteoporosis.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 80
Incorrect
-
In which situation is a stretch reflex such as knee jerk likely to be exaggerated?
Your Answer: In lower motor neuron lesion
Correct Answer: In upper motor neuron lesion
Explanation:A stretch reflex is a monosynaptic reflex that causes muscle contraction in response to stretching within that muscle. The sensory apparatus in a muscle that are sensitive to stretch are the muscle spindles. The patellar (knee jerk) reflex is an example. In upper motor neuron lesions, the stretch reflexes tend to be brisk due to loss of inhibitory signals on gamma neurons through the lateral reticulospinal tract.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 81
Incorrect
-
Which structure holds the duodenojejunal flexure in place?
Your Answer: Hepatoduodenal ligament
Correct 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 82
Correct
-
The pattern of drainage of the lymphatic and venous systems of the anterior abdominal wall is arranged around a horizontal plane above which drainage is in a cranial direction and below which drainage is in a caudal direction. Which horizontal plane is being referred to?
Your Answer: Level of the umbilicus
Explanation:The umbilicus is a key landmark for the lymphatic and venous drainage of the abdominal wall. Above it, lymphatics drain into the axillary lymph nodes and the venous blood drains into the superior epigastric vein, into the internal thoracic vein. Below it, lymphatics drain into the superficial inguinal lymph nodes while venous blood drains into the inferior epigastric vein and the external iliac vein.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 83
Correct
-
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: 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 84
Correct
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A surgeon performing a Whipple's procedure, that involves mobilizing the head of the pancreases, accidentally injured a structure immediately posterior to the neck of the pancrease which bled out. Which structure is most likely to have been injured?
Your Answer: Superior mesenteric artery
Explanation:The structure immediately posterior to the neck of the pancreas is the superior mesenteric vein. The neck of the pancreas lies anterior to the superior mesenteric vein, which joins with the splenic vein to form the portal vein.
The superior mesenteric artery (SMA) is also located in proximity to the neck of the pancreas. Specifically, the SMA emerges from the abdominal aorta just below the level of the pancreas and passes posterior to the neck of the pancreas before it descends into the mesentery to supply the intestines. Thus, both the superior mesenteric vein and the superior mesenteric artery are key vascular structures related to the posterior aspect of the neck of the pancreas.
Bleeding out would suggest an arterial injury.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 85
Incorrect
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Which of the following veins empties into the left renal vein?
Your Answer: Left phrenic
Correct Answer: Left suprarenal
Explanation:The left suprarenal vein empties into the left renal vein which crosses the vertebral column to reach the inferior vena cava. The left renal vein also receives the left gonadal vein.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 86
Incorrect
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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: ACTH-secreting pituitary adenoma
Correct 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 87
Correct
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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 88
Incorrect
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The likely cause of a tender and swollen breast in a lactating mother is:
Your Answer: Fibrocystic disease
Correct Answer: Acute mastitis
Explanation:Acute mastitis results due to bacterial infection of the breast and results in signs of inflammation. It commonly occurs 2-3 weeks postpartum and common causative microorganisms are Staphylococcus aureus, Streptococcus species, and Escherichia coli. Complications like an abscess can be avoided by prompt treatment, which includes antibiotics and rest along with continued lactation.
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This question is part of the following fields:
- Pathology
- Women's Health
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Question 89
Incorrect
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An 26-year-old man sought admission due to persistent non-bloody diarrhoea. The patient is HIV-positive. Examination of stool sample showed numerous acid-fast cysts. Which of the following organism is the most likely cause of diarrhoea?
Your Answer: Mycobacterium avium-intracellular complex
Correct Answer: Cryptosporidium parvum
Explanation:Cryptosporidium parvum is one of several species that causes cryptosporidiosis, a parasitic disease of the mammalian intestinal tract. Primary symptoms of C. parvum infection are acute, watery, and non-bloody diarrhoea. C. parvum infection is of particular concern in immunocompromised patients, where diarrhoea can reach 10–15 l per day.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 90
Incorrect
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A 62-year-old male smoker, presented with shortness of breath, chronic cough and haemoptysis over the last three months. He has developed a fat pad in the base of his neck, rounded face, acne and osteoporosis. Which of the following is the most likely pulmonary disease that is causing these symptoms and findings?
Your Answer: Bronchial carcinoid
Correct Answer: Small-cell anaplastic carcinoma
Explanation:Small cell lung cancer is a highly aggressive form of lung cancer. It is thought to originate from neuroendocrine cells in the bronchus called Feyrter cells and is often associated to ectopic production of hormones like ADH and ACTH that result in paraneoplastic syndromes and Cushing’s syndrome.
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This question is part of the following fields:
- Pathology
- Respiratory
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Question 91
Incorrect
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During a clinical rotation in the ENT clinic, you observe a flexible bronchoscopy. As the scope is passed down the trachea, you see a cartilaginous structure that resembles a ship's keel and separates the right and the left main stem bronchi. This structure is the:
Your Answer: Costal cartilage
Correct Answer: Carina
Explanation:The carina (a keel-like cartilage) is found at the bifurcation of the trachea separating the right from the left main stem bronchi. It is a little more to the left than to the right.
The cricoid cartilage is the inferior and posterior cartilage of the larynx.
The costal cartilage on the other hand elongates the ribs anteriorly and contribute to the elasticity of the thoracic cage.
The pulmonary ligament is a fold of pleura located below the root of the lung.
Tracheal rings are rings of cartilage that support the trachea.
Peritracheal fascia is a layer of connective tissue that invests the trachea from the outside and is not visible on bronchoscopy.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 92
Incorrect
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A surgeon ligates the left middle suprarenal artery while carrying out a left adrenalectomy. Where does the left middle suprarenal artery originate?
Your Answer: Coeliac artery
Correct 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 93
Incorrect
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If a patient takes long-term corticosteroid therapy, which of the following diseases is most likely to develop?
Your Answer: Paget’s disease of bone
Correct Answer: Osteoporosis
Explanation:One of the complications of long-term intake of corticosteroids is osteoporosis. Some guidelines recommend prophylactic calcium and vitamin D supplementation in patients who take more than 30 mg hydrocortisone or 7.5 mg of prednisolone daily.
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This question is part of the following fields:
- Orthopaedics
- Pathology
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Question 94
Correct
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What Is the mechanism behind rhesus incompatibility in a new born baby?
Your Answer: Type II hypersensitivity
Explanation:In type II hypersensitivity the antibodies that are produced by the immune response bind to the patients own cell surface antigens. These antigens can be intrinsic or extrinsic. Destruction occurs due to antibody dependent cell mediated antibodies. Antibodies bind to the cell and opsonise the cell, activating phagocytes to destroy that cell e.g. autoimmune haemolytic anaemia, Goodpasture syndrome, erythroblastosis fetalis, pernicious anaemia, Graves’ disease, Myasthenia gravis and haemolytic disease of the new-born.
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This question is part of the following fields:
- Inflammation & Immunology; Haematology
- Pathology
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Question 95
Incorrect
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A 23 year old woman is Rh -ve and she delivered a baby with a Rh+ blood group. What measure can be performed to prevent Rh incompatibility in the next pregnancy?
Your Answer: Blood transfusion
Correct Answer: Immunoglobulin D
Explanation:Rh disease is also known as erythroblastosis fetalis and is a disease of the new-born. In mild states it can cause anaemia with reticulocytosis and in severe forms causes severe anaemia, morbus hemolytcus new-born and hydrops fetalis. RBCs of the Rh+ baby can cross the placenta and enter into the maternal blood. As she is Rh- her body will form antibodies against the D antigen which will pass through the placenta in subsequent pregnancies.
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This question is part of the following fields:
- General
- Physiology
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Question 96
Incorrect
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Gram positive bacteria differ from gram negative bacteria due to the presence of which of the following structures?
Your Answer: Cell wall
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 97
Incorrect
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After a total colectomy and ileotomy, a 50-year old diabetic man who was a known case of diabetic nephropathy had persistent metabolic acidosis. The patient appeared well perfused, with normal vital signs and normal fluid balance. Investigations revealed:
Sodium = 132 mmol/l
Potassium = 6.6 mmol/l
Creatinine = 185 μmol/l (2.16 mg/dl)
Chloride = 109 μmol/l
8am cortisol = 500 nmol/l (18 μg/dl)
pH = 7.29, p(CO2) = 27 mmHg
p(O2) = 107 mmHg
standard bicarbonate = 12 mmol/l.
What is the likely causes of his acidosis?Your Answer: Lactic acidosis
Correct Answer: Renal tubular acidosis
Explanation:Acidosis here is due to low bicarbonate. The low p(CO2) is seen in compensation. The anion gap is normal, ruling out intra-abdominal ischaemia (which leads to metabolic acidosis). If it was a gastrointestinal aetiology, low potassium would be seen. The history of diabetic nephropathy predisposes to renal tubular acidosis. Type 4 (hyporeninaemic hypoaldosteronism) is associated with high potassium and is found in diabetic and hypertensive renal disease.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 98
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 99
Incorrect
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An organ transplant patient may be at risk of developing which type of cancer?
Your Answer:
Correct Answer: Skin cancer
Explanation:The most common malignancies encountered in the post–solid organ transplant setting are non-melanoma skin cancers, post-transplant lymphoproliferative disorders and Kaposi’s sarcoma (KS). The pathogenesis of these tumours is likely related to the immunosuppressive drugs used post-transplantation and subsequent viral infection.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 100
Incorrect
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Which of the following compensatory parameters is responsible for causing an increase in the blood pressure in a 30 year old patient with a BP of 40 mmHg?
Your Answer:
Correct Answer: Baroreceptor reflex
Explanation:The baroreflex or baroreceptor reflex is one of the body’s homeostatic mechanisms for regulating blood pressure. It provides a negative feedback response in which an elevated blood pressure will causes blood pressure to decrease; similarly, decreased blood pressure depresses the baroreflex, causing blood pressure to rise. The system relies on specialised neurones (baroreceptors) in the aortic arch, carotid sinuses and elsewhere to monitor changes in blood pressure and relay them to the brainstem. Subsequent changes in blood pressure are mediated by the autonomic nervous system. Baroreceptors include those in the auricles of the heart and vena cava, but the most sensitive baroreceptors are in the carotid sinuses and aortic arch. The carotid sinus baroreceptors are innervated by the glossopharyngeal nerve (CN IX); the aortic arch baroreceptors are innervated by the vagus nerve (CN X).
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This question is part of the following fields:
- Cardiovascular
- Physiology
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SESSION STATS - PERFORMANCE PER SPECIALTY
