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Question 1
Correct
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A patient is diagnosed with lung cancer. His physician told him that his lung cancer type is aggressive. It can grow rapidly and may undergo early metastasis, however it is very sensitive to chemotherapy and radiotherapy. Which lung cancer type is most likely present
Your Answer: Small-cell carcinoma
Explanation:Small-cell lung carcinoma (SCLC) is a type of highly malignant cancer that most commonly arises within the lung. SCLC usually metastasizes widely very early on in the natural history of the tumour, and in nearly all cases responds dramatically to chemotherapy and/or radiotherapy. Surgery has no role in the treatment of this disease.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 2
Correct
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The proximal tubule is the portion of the ductal system of the nephron of the kidney which leads from Bowman's capsule to the loop of Henle. Which of the following is most likely to be seen in a sample of fluid leaving the proximal tubule?
Your Answer: It will have no amino acids
Explanation:The proximal tubule is the portion of the duct system of the nephron leading from Bowman’s capsule to the loop of Henlé. The most distinctive characteristic of the proximal tubule is its brush border (or ‘striated border’). The luminal surface of the epithelial cells of this segment of the nephron is covered with densely packed microvilli forming a border which greatly increases the luminal surface area of the cells, presumably facilitating their reabsorptive function. Glucose, amino acids, inorganic phosphate, and some other solutes are100% reabsorbed via secondary active transport through co-transporters driven by the sodium gradient out of the nephron.
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This question is part of the following fields:
- Physiology
- Renal
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Question 3
Correct
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Which of the following terms best describes the movement of leukocytes towards a specific target?
Your Answer: Chemotaxis
Explanation:The movement of leukocytes towards a chemical mediator is termed chemotaxis and the mediators likewise called chemoattractants.
Diapedesis is the squeezing of the leukocytes from the capillary wall into the intercellular space.
Endocytosis is engulfing of a small substance by the cells e.g. glucose, protein, fats.
Margination is lining of the WBC along the periphery of the blood vessel.
Adhesion is attachment with the vessel wall.
Phagocytosis is described as engulfing the bacteria or the offending substance.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 4
Correct
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What percentage of the cardiac output is delivered to the brain?
Your Answer: 15%
Explanation:Among all body organs, the brain is most susceptible to ischaemia. Comprising of only 2.5% of total body weight, the brain receives 15% of the cardiac output. Oxygen extraction is also higher with venous oxygen levels approximating 13 vol%, and arteriovenous oxygen difference of 7 vol%.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 5
Correct
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At which cervical level does the common carotid artery bifurcate into the internal and external carotid arteries?
Your Answer: C4
Explanation:The common carotid arteries are present on the left and right sides of the body. These arteries originate from different sources, but follow symmetrical courses. The right common carotid originates in the neck from the brachiocephalic trunk; the left from the aortic arch in the thorax. These split into the external and internal carotid arteries at the upper border of the thyroid cartilage, at around the level of the fourth cervical vertebra.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 6
Correct
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Which of these structures is most likely to be damaged if a patient loses consciousness days or weeks after an otherwise insignificant head trauma, especially in elderly patients?
Your Answer: Dural bridging vein
Explanation:A subdural haematoma is a type of hematoma, usually associated with traumatic brain injury, in which blood collects between the dura mater and the pia-arachnoid mater. Symptoms of subdural haemorrhage have a slower onset than those of epidural haemorrhages because the lower pressure veins bleed more slowly than arteries. These injuries are more common in elderly patients, especially those taking antiplatelet or anticoagulant drugs. Oedema and increased intracranial pressure are unusual.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 7
Correct
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Myoglobin is released as a result of rhabdomyolysis from damaged skeletal muscles. What function do they perform in the muscle?
Your Answer: Acts like haemoglobin and binds with O2
Explanation:Myoglobin is a pigmented globular protein made up of 153 amino acids with a prosthetic group containing haem around which the apoprotein folds. It is the primary oxygen carrying protein of the muscles. The binding of oxygen to myoglobin is unaffected by the oxygen pressure as it has an instant tendency to bind given its hyperbolic oxygen curve. It releases oxygen at very low pO2 levels.
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This question is part of the following fields:
- General
- Physiology
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Question 8
Correct
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A 32-year-old man presented with a metabolic acidosis and increased anion gap. What is the most likely cause of the changes of the anion gap in this patient?
Your Answer: Lactic acidosis
Explanation:High anion gap in metabolic acidosis is caused generally by the elevation of the levels of acids like ketones, lactate, sulphates in the body, which consume the bicarbonate ions. Other causes of a high anion gap include overdosing on salicylates, uraemia, rhabdomyolysis, hypocalcaemia, hypomagnesaemia, or ingestion of toxins such as ethylene glycol, methanol, propyl alcohol, cyanide and iron.
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This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
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Question 9
Correct
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A butcher accidentally cut himself on his right index finger. Which of the following substances when in contact with the basement membrane of the injured vasculature will activate the coagulation cascade as well as the kinin system in a first response to this injury?
Your Answer: Hageman factor
Explanation:Hageman factor/factor XII in the intrinsic pathway activates prekallikrein and factor XI. Deficiency will not cause excessive bleeding as other coagulation factors will be utilized but the PTT will be greater than 200 seconds.
Thromboxane promotes platelet aggregation and causes vasoconstriction.
Plasmin, which is cleaved from plasminogen acts as an anticoagulant which breaks down thrombi.
Platelet activating factor promotes platelet aggregation and is also chemotactic to neutrophils.
Histamine acts as a vasodilator.
Platelet inhibiting factor acts an anticoagulant.
Renin is a hormone released from the kidney that causes vasoconstriction and water retention.
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This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
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Question 10
Correct
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Which of the following is a likely consequence of severe diarrhoea?
Your Answer: A decrease in the sodium content of the body
Explanation:Diarrhoea can occur due to any of the numerous aetiologies, which include infectious, drug-induced, food related, surgical, inflammatory, transit-related or malabsorption. Four mechanisms have been implicated in diarrhoea: increased osmotic load, increased secretion, inflammation and decreased absorption time. Diarrhoea can result in fluid loss with consequent dehydration, electrolyte loss (Na+, K+, Mg2+, Cl–) and even vascular collapse. Loss of bicarbonate ions can lead to a metabolic acidosis.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 11
Correct
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A lady presents to the out patient clinic with a painful boil on the skin of her mons pubis. Which nerve supplies the skin of the mons pubis?
Your Answer: Anterior labial
Explanation:Anterior labial branch is the terminal branch of the ilioinguinal nerve that innervates the skin of the mons pubis in women and the skin of the anterior scrotum in men.
The femoral branch of genitofemoral nerve innervates the upper medial thigh.
The iliohypogastric innervates muscles of the abdominal wall.
The subcostal nerve innervates muscles of the abdominal wall and the skin of the lower abdominal wall.
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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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An anatomy instructor is giving a demonstration of the right lung. Which of the statements about the right lung made by the demonstrator is correct?
Your Answer: Its upper lobar bronchus lies behind and above the right pulmonary artery
Explanation:The root of the lungs on both sides are similar in that the pulmonary veins are anterior and inferior while the bronchus is posterior. However, on the right side, the pulmonary arteries are anterior to the bronchus while on the left side the pulmonary arteries are superior to the bronchus. The lingual is only found on the left lung. The mediastinum is the space in the thorax between the two pleural sacs and does not contain any lung. The right lung, having three lobes, is slightly larger than the left lung. On both sides, the phrenic nerves passes in front of the root of the lung.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 13
Incorrect
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The dilator pupillae muscle is innervated by postganglionic sympathetic fibres. Where do the postganglionic sympathetic fibres originate?
Your Answer: Spinal cord (T1–L2)
Correct Answer: Superior cervical ganglion
Explanation:The postganglionic sympathetic axons are derived from the superior cervical ganglion and innervate the eye and lacrimal gland allowing for vasoconstriction of the iris and sclera, pupillary dilation, widening of the palpebral fissure, and a reduction in tear production.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 14
Correct
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A 33-year old lady presented to the gynaecology clinic with amenorrhoea for 6 months and a recent-onset of milk discharge from her breasts. She was not pregnant or on any medication. On enquiry, she admitted to having frequent headaches the last 4 months. Which of the following findings would you expect to see in her condition?
Your Answer: Hyperprolactinaemia
Explanation:Excessively high levels of prolactin in the blood is called hyperprolactinaemia. Normally, prolactin levels are less than 580 mIU/l in females and less than 450 mIU/l in men. The biologically inactive macroprolactin can lead to a false high reading. However, the patient remains asymptomatic. Dopamine down-regulates prolactin whereas oestrogen upregulates it. Hyperprolactinaemia can be caused due to lack of inhibition (compression of pituitary stalk or low dopamine levels), or increased production due to a pituitary adenoma (prolactinoma). Either of these causes can lead to a prolactin level of 1000-5000 mIU/l. However, levels more than 5000mIU/l are usually associated due to an adenoma and >100,000 mIU/l are seen in macroadenomas (tumours < 1cm in diameter). Increased prolactin causes increased dopamine release from the arcuate nucleus of hypothalamus. This increased dopamine in turn, inhibits the GnRH (Gonadotrophin Releasing Hormone) thus blocking gonadal steroidogenesis resulting in the symptoms of hyperprolactinaemia. In women, it includes hypoestrogenism, anovulatory infertility, decreased or irregular menstruation or complete amenorrhoea. It can even cause production of breast milk, loss of libido, vaginal dryness and osteoporosis. In men, the symptoms include impotence, decreased libido, erectile dysfunction and infertility. In men, treatment can be delayed due to late diagnosis as they have no reliable indicator such as menstruation that might indicate a problem. Most of the male patients seek help only when headaches and visual defects start to surface.
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This question is part of the following fields:
- Endocrine
- Pathology
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Question 15
Correct
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A victim of road traffic accident presented to the emergency department with a blood pressure of 120/90 mm Hg, with a drop in systolic pressure to 100 mm Hg on inhalation. This is known as:
Your Answer: Pulsus paradoxus
Explanation:Weakening of pulse with inhalation and strengthening with exhalation is known as pulsus paradoxus. This represents an exaggeration of the normal variation of the pulse in relation to respiration. It indicates conditions such as cardiac tamponade and lung disease. The paradox refers to the auscultation of extra cardiac beats on inspiration, as compared to the pulse. Due to a decrease in blood pressure, the radial pulse becomes impalpable along with an increase in jugular venous pressure height (Kussmaul sign). Normal systolic blood pressure variation (with respiration) is considered to be >10 mmHg. It is >100 mmHg in Pulsus paradoxus. It is also predictive of the severity of cardiac tamponade.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 16
Correct
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A 24-year old, lactating mother presents to the clinic with a tender, 1.5cm mass just below the right nipple, which shows multiple fissures. What finding is likely associated with her condition?
Your Answer: Staphylococcus aureus infection
Explanation:Breast abscess occur commonly in lactating mothers in the postpartum period due to cracking of the nipple. It is commonly caused due to Staphylococcus aureus infection. Fat necrosis usually results from trauma wherein an ill-defined mass is formed. Ductal carcinomas are malignant masses which are not tender usually, and rare in the young age group. Plasma cell mastitis affect women in an older age group. Sclerosing adenosis is a type of fibrocystic disease which can lead to a tender, cystic mass but no fissuring or cracks are seen in the nipple. Fibroadenoma and lipomas are non-tender, well-defined masses.
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This question is part of the following fields:
- Pathology
- Women's Health
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Question 17
Correct
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A 30-year-old woman is diagnosed with Hodgkin's lymphoma. Which of the following chemotherapy regimens would be used in this case?
Your Answer: ABVD
Explanation:ABVD is a chemotherapy regimen used in the first-line treatment of Hodgkin’s lymphoma. It consists of concurrent treatment with the chemotherapy drugs, adriamycin, bleomycin, vinblastine and dacarbazine. It supplanted the older MOPP protocol.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 18
Correct
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A 5 year-old-child with fever complains of sore throat . She was brought to her paediatrician for consult because she has also developed a rash and has swollen lymph nodes. Upon physical examination she cried when her liver was palpated and the tip of her spleen is slightly palpable. Full blood count shows haemoglobin 13 g/dL, Haematocrit 40%, white blood cell count 13x109/L with a WBC differential count of 45 neutrophils, 4 bands, 26 lymphocytes, 15 atypical lymphocytesm, 10 monocytes and 1 eosinophil. Whick is the most likely infectious agent that is responsible for the patient's condition?
Your Answer: Epstein–Barr virus
Explanation:Epstein-Barr virus (EBV), also known as human herpes virus 4,is a member of the herpes virus family. EBV spreads most commonly through bodily fluids, primarily saliva. EBV can cause infectious mononucleosis. Symptoms of EBV can include fatigue, fever, inflamed throat, swollen lymph nodes in the neck, enlarged spleen, swollen liver and rash.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 19
Correct
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Evaluation of a 60-year old gentleman, who has been a coal miner all his life and is suspected to have pulmonary fibrosis reveals the following: FEV1 of 75% (normal > 65%), arterial oxygen saturation 92%, alveolar ventilation 6000 ml/min at a tidal volume of 600 ml and a breathing rate of 12 breaths/min. There are also pathological changes in lung compliance and residual volume. Calculate his anatomical dead space.
Your Answer: 100 ml
Explanation:Dead space refers to inhaled air that does not take part in gas exchange. Because of this dead space, taking deep breaths slowly is more effective for gas exchange than taking quick, shallow breaths where a large proportion is dead space. Use of a snorkel by a diver increases the dead space marginally. Anatomical dead space refers to the gas in conducting areas such as mouth and trachea, and is roughly 150 ml (2.2 ml/kg body weight). This corresponds to a third of the tidal volume (400-500 ml). It can be measured by Fowler’s method, a nitrogen wash-out technique. It is posture-dependent and increases with increase in tidal volume. Physiological dead space is equal to the anatomical dead space plus the alveolar dead space, where alveolar dead space is the area in the alveoli where no effective exchange takes place due to poor blood flow in capillaries. This physiological dead space is very small normally (< 5 ml) but can increase in lung diseases. Physiological dead space can be measured by Bohr’s method. Total ventilation per minute (minute ventilation) is given by the product of tidal volume and the breathing rate. Here, the total ventilation is 600 ml times 12 breaths/min = 7200 ml/min. The problem mentions alveolar ventilation to be 6000 ml/min. Thus, the difference between the alveolar ventilation and total ventilation is 7200 – 6000 ml/min = 1200 ml/min, or 100 ml per breath at 12 breaths per min. This 100 ml is the dead space volume.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 20
Correct
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A 59-year-old man was brought to the emergency department by his family after complaining of sudden, severe upper back pain and a ripping sensation, that radiated to his neck. On arrival, his pulse was weak in one arm compared with the other however his ECG result was normal. Which of the following is most probably the cause of these findings and symptoms?
Your Answer: Acute aortic dissection
Explanation:Acute aortic dissection is a serious condition in which the inner layer of the aorta tears and the blood flows in between the inner and middle layers of the aorta causing their separation (dissection). Aortic dissection can lead to rupture or decreased blood flow to organs. Clinical manifestations most often include the sudden onset of severe, tearing or ripping chest pain that can radiate to the shoulder, back or neck; syncope; altered mental status; dyspnoea; pale skin; stroke symptoms etc. The diagnosis of acute aortic dissection is based on clinical findings, imaging studies, electrocardiography and laboratory analysis.
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This question is part of the following fields:
- Cardiovascular
- Pathology
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Question 21
Correct
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A CT-scan report of a patient with gastric carcinoma shows that the lymph nodes around the coeliac trunk are enlarged. The coeliac trunk:
Your Answer: Gives rise to the splenic, left gastric and common hepatic arteries
Explanation:The coeliac trunk is a branch of the aorta arising just below the aortic hiatus of the diaphragm to pass nearly horizontally forward to divide into 3 large branches i.e. the left gastric, the hepatic and the splenic arteries. Occasionally it may give off one of the inferior phrenic arteries. It is covered by the lesser omentum and on the right side bordered by the right coeliac ganglion and the cardiac end of the stomach. Inferiorly it is bordered by the upper border of the pancreas and splenic vein. The embryonic midgut is supplied by the superior mesenteric artery.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 22
Correct
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Multiple cells were labelled using a fluorescent dye that doesn’t cross the cell membrane. One cell in the middle was bleached with a light that destroys the dye, but the cell soon recovers its stain. The presence of which structures best explains this?
Your Answer: Gap junctions
Explanation:Gap junctions are attachments between cells that permit intercellular communication e.g. they permit current flow and electrical coupling between myocardial cells. They allow direct electrical transmission among cells and also permit certain substance to pass through as well. They are either homotypic, formed by two identical hemichannels or heterotypic, formed by different hemichannels.
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This question is part of the following fields:
- General
- Physiology
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Question 23
Correct
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A 7-year-old girl is given cephalexin to treat an infection and develops hives, with localised facial oedema. Which of the following conditions will cause localised oedema?
Your Answer: Angio-oedema
Explanation:Angio-oedema, is the rapid swelling of the skin, mucosa and submucosal tissues. The underlying mechanism typically involves histamine or bradykinin. The version related to histamine is to due an allergic reaction to agents such as insect bites, food, or medications. The version related to bradykinin may occur due to an inherited C1 esterase inhibitor deficiency, medications e.g. angiotensin converting enzyme inhibitors, or a lymphoproliferative disorder.
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This question is part of the following fields:
- Physiology
- Renal
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Question 24
Correct
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Different substances have different renal clearance rates. Which of the following substances should have the lowest renal clearance rate in a healthy patient?
Your Answer: Glucose
Explanation:Under normal conditions the renal clearance of glucose is zero, since glucose is completely reabsorbed in the renal tubules and not excreted. Glycosuria – the excretion of glucose into the urine- is nearly always caused by elevated blood glucose levels, most commonly due to untreated diabetes mellitus.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 25
Correct
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If your EEG shows waves with a frequency range of 8-12 Hz, the waves most likely to be seen are:
Your Answer: Alpha
Explanation:Electroencephalography (EEG) is the neurophysiological measurement of the electrical activity of the brain. It is done by placing electrodes on the scalp or subdurally. In reality, the electrical currents are not measured, but rather the voltage differences between different parts of the brain. Four major types of EEG activity are recognized, which are alpha, beta, delta and theta.
Alpha waves, also known as Berger’s waves ranges in frequency from 8-12 Hz. Best detected with eyes closed, alpha waves are characteristic of a relaxed, alert state of consciousness. An alpha-like normal variant called mu is sometimes seen over the motor cortex (central scalp) and attenuates with movement or, rather, with the intention to move.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 26
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 27
Correct
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The mandibular nerve, which is the largest of the 3 divisions of the trigeminal nerve, exits the cranial cavity through which foramen?
Your Answer: Foramen ovale
Explanation:At the base of the skull the foramen ovale is one of the larger of the several holes that transmit nerves through the skull. The following structures pass through foramen ovale: mandibular nerve, motor root of the trigeminal nerve, accessory meningeal artery, lesser petrosal nerve, a branch of the glossopharyngeal nerve, emissary vein connecting the cavernous sinus with the pterygoid plexus of veins and occasionally the anterior trunk of the middle meningeal vein.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 28
Correct
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A 70-year-old male who has smoked since his teens complains of progressive shortness of breath and a persistent cough. He is diagnosed with COPD. Which of the following abnormalities is most likely to be present in his pulmonary function tests?
Your Answer: Increased residual volume
Explanation:Chronic obstructive pulmonary disease (COPD) is a type of obstructive lung disease characterized by long-term poor airflow. The main symptoms include shortness of breath and cough with sputum production. The best diagnostic test for evaluating patients with suspected chronic obstructive pulmonary disease (COPD) is lung function measured with spirometry. Key spirometrical measures may be obtained with a portable office spirometer and should include forced vital capacity (FVC) and the normal forced expiratory volume in the first second of expiration (FEV1). The ratio of FEV1 to forced vital capacity (FEV1/FVC) normally exceeds 0.75. Patients with COPD typically present with obstructive airflow. Complete pulmonary function testing may show increased total lung capacity, functional residual capacity and residual volume. A substantial loss of lung surface area available for effective oxygen exchange causes diminished carbon monoxide diffusion in the lung (DLco) in patients with emphysema. Tobacco smoking is the most common cause of COPD, with factors such as air pollution and genetics playing a smaller role.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 29
Correct
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A 50-year old gentleman who was admitted for elective surgery was found to have haemoglobin 9.5 g/dl, white blood cell count of 1.4 × 109/l and a mean corpuscular volume (MCV) of 134 fl. Which of the following is the likely finding on his peripheral blood smear?
Your Answer: Hypersegmented neutrophils
Explanation:The likely diagnosis is megaloblastic anaemia, which also shows the presence of hypersegmented neutrophils.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 30
Correct
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A 40-year old lady presented to the hospital with fever and mental confusion for 1 week. On examination, she was found to have multiple petechiae all over her skin and mucosal surfaces. Blood investigations revealed low platelet count and raised urea and creatinine. A platelet transfusion was carried out, following which she succumbed to death. Autopsy revealed pink hyaline thrombi in myocardial arteries. What is the likely diagnosis?
Your Answer: Thrombotic thrombocytopenic purpura
Explanation:Hyaline thrombi are typically associated with thrombotic thrombocytopenic purpura (TTP), which is caused by non-immunological destruction of platelets. Platelet transfusion is contraindicated in TTP. Platelets and red blood cells also get damaged by loose strands of fibrin deposited in small vessels. Multiple organs start developing platelet-fibrin thrombi (bland thrombi with no vasculitis) typically at arteriocapillary junctions. This is known as ‘thrombotic microangiopathy’. Treatment consists of plasma exchange.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 31
Correct
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Question 32
Correct
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A 55- year old male patient with cancer of the head of the pancreas was to undergo whipple's operation to have the tumour removed. During the surgery, the surgeon had to ligate the inferior pancreaticoduodenal artery to stop blood supply to the head of the pancreas. Which of the following arteries does the inferior pancreaticoduodenal artery branch from?
Your Answer: Superior mesenteric artery
Explanation:The inferior pancreaticoduodenal artery is a branch of the superior mesenteric artery or from the first intestinal branch of the superior mesenteric artery. Once given off, it runs to the right between the pancreatic head and the duodenum and then ascends to form an anastomosis with the superior pancreaticoduodenal artery.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 33
Correct
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In the case of an injury to the sub sartorial canal, which of the following structures is most likely to be injured?
Your Answer: Nerve to vastus medialis
Explanation:The adductor canal (sub sartorial canal) is situated in the middle third of the thigh.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 34
Correct
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Which of the following is a potential cause of a positive D-dimer assay?
Your Answer: Deep venous thrombosis
Explanation:A D-dimer test is performed to detect and diagnose thrombotic conditions and thrombosis. A negative result would rule out thrombosis and a positive result although not diagnostic, is highly suspicious of thrombotic conditions like a deep vein thrombosis, pulmonary embolism as well as DIC.
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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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A 47 year-old woman was admitted for elective cholecystectomy, with a past history of easy bruising and heavy menstrual periods. The patient was also diagnosed with Willebrand's disease. Willebrand's disease is:
Your Answer: Autosomal dominant
Explanation:von Willebrand disease is an autosomal dominant disorder marked by the deficiency of vWF, a large protein synthesized by the endothelial cells and megakaryocytes. It mediates adhesion of platelets to the subendothelium at site of vascular injury. Disease characteristics include impaired platelet adhesion, prolonged bleeding time and a functional deficiency of factor VIII (vWF is its carrier protein).
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This question is part of the following fields:
- General
- Physiology
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Question 36
Correct
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A 47 -year-old male was admitted due to a bleeding peptic ulcer. On his 3rd hospital day, he developed a cardiac arrhythmia. His serum potassium was markedly elevated. What is the most likely cause of hyperkalaemia in this patient?
Your Answer: Multiple blood transfusions
Explanation:Patients with gastrointestinal bleeding often require blood transfusion. Among the various side effects of blood transfusions, is the increase of potassium levels. The use of stored blood for transfusions is followed by an increase of serum potassium levels. Potassium level increases are more pronounced in patients who receive blood stored for more than 12 d. Furthermore, the lysis and destruction of red blood cells, especially in the transfusion of older PRBCs, can further increase potassium levels. Excessive use of a PPi has been associated with hyperkaelemia however would be less likely in this acute setting.
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This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
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Question 37
Correct
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In which of the following compartments of the femoral sheath is the femoral artery located?
Your Answer: Lateral compartment
Explanation:The femoral sheath also known as the crural sheath is made up of three compartments; lateral, intermediate and the medial. The femoral artery is contained in the lateral compartment of the femoral sheath while the femoral vein is in the intermediate compartment.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 38
Correct
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What is the linea aspera:
Your 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 39
Correct
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A patient is diagnosed with Conn’s syndrome. Aldosterone is secreted from where?
Your 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 40
Correct
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A patients sciatic nerve has been severed following a stab injury. What would be affected?
Your Answer: There would still be cutaneous sensation over the anteromedial surface of the thigh
Explanation:The sciatic nerve supplies nearly all of the sensation of the skin of the leg and the muscles of the back of the thigh, leg and foot. A transection of the sciatic nerve at its exit from the pelvis will affect all the above-mentioned functions except cutaneous sensation over the anteromedial surface of the thigh, which comes from the femoral nerve.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 41
Correct
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A 35 year-old woman is undergoing thyroidectomy. The external laryngeal nerve may be injured whilst ligating this artery during the procedure due to its close relationship?
Your Answer: Superior thyroid artery
Explanation:The superior thyroid artery arises from the external carotid artery just below the level of the greater cornu of the hyoid bone and ends in the thyroid gland. This artery must be ligated at the thyroid when conducting a thyroidectomy. If the artery is severed, but not ligated, it will bleed profusely. In order to gain control of the bleeding, the surgeon may need to extend the original incision laterally to ligate the artery at its origin at the external carotid artery. The external laryngeal branch of the superior laryngeal nerve courses in close proximity to the superior thyroid artery, making it at risk for injury during surgery.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 42
Correct
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You are asked to help a junior medical student studying anatomy to identify the left lung. Which of the following features found only in the left lung will you use the identify it?
Your Answer: Cardiac notch
Explanation:Oblique fissure: is found on both the left and the right lungs. It separates the upper from the lower lobes in both lungs and the middle lobe from the lower lobe in the right lung(which has three lobes.)
The superior lobar bronchus is found in both lungs.
Cardiac notch: found only on the left lung.
Horizontal fissure: a deep groove separating the middle lobe from the upper lobe of the right lung is absent on the left lung.
Diaphragmatic surface: refers to the part of the lung, both the left and the right, that is in contact with the diaphragm.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 43
Correct
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A 25 year old primi gravida lady was scheduled for a regular antenatal check up. During the vaginal exam of this lady, the registrar discovered a malignant growth on the anterior wall of her vagina. Which of the following structures, adjacent to the vagina, is likely to be involved as well?
Your Answer: Fundus of the bladder
Explanation:The fundus of the bladder is related anatomically to the anterior surface of the vagina and the urethra as well. If there was a malignant growth in the anterior surface of the vagina, then most likely the fundus of the bladder would be involved as well aspotentially the urethra.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 44
Correct
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From which source does the lingual artery originate?
Your Answer: External carotid
Explanation:The lingual artery arises from the external carotid between the superior thyroid artery and facial artery. It can be located easily on the lower surface of the tongue. The terminal branch of the lingual artery is the deep lingual artery. On its course the lingual artery gives off side branches: dorsal lingual branches that supply the dorsum of the tongue till the epiglottis; sublingual artery that supplies the sublingual gland.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 45
Correct
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Which of these conditions causes haematuria, hypertension and proteinuria in children, usually after a streptococcal infection?
Your Answer: Acute nephritic syndrome
Explanation:Nephritic syndrome (or acute nephritic syndrome) is a syndrome comprising of signs of nephritis. Children between 2 and 12 are most commonly affected, but it may occur at any age. Predisposing factors/causes include:
Infections with group A streptococcal bacteria (acute post-streptococcal glomerulonephritis).
Primary renal diseases: immunoglobulin A nephropathy, membranoproliferative glomerulonephritis, idiopathic rapidly progressive crescentic glomerulonephritis.
Secondary renal diseases: subacute bacterial endocarditis, infected ventriculo–peritoneal shunt, glomerulonephritis with visceral abscess, glomerulonephritis with bacterial, viral or parasitic infections.
Multisystem diseases.
By contrast, nephrotic syndrome is characterized by only proteins moving into the urine.
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This question is part of the following fields:
- Physiology
- Renal
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Question 46
Correct
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The transmembrane proteins responsible for resting membrane potential of vascular smooth muscle cells was blocked by a drug. Which of the following transmembrane proteins were blocked by this drug?
Your Answer: 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 47
Correct
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A 55 year old man presented with a 4 day history of cough and fever. His sputum culture showed the presence of Strep pneumoniae. Which of the following substances produced by the inflammatory cells will result in effective clearance of this organism from the lung parenchyma?
Your Answer: Hydrogen peroxide
Explanation:Hydrogen peroxide is produced by myeloperoxidase to form a potent oxidant that eliminates bacteria, but is not effective in chronic granulomatous diseases.
Platelet activating factor will lead to the activation, adhesion and aggregation of platelets but will not directly kill bacteria.
Prostaglandins cause vasodilation but do not activate neutrophils.
Kallikrein promotes formation of bradykinin that leads to vasodilation.
Leukreines increase vascular permeability.
Cytokines are communicating molecules between immune cells but directly will not kill bacteria.
Interleukins will regulate the immune response.
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This question is part of the following fields:
- Inflammation & Immunology; Respiratory
- Pathology
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Question 48
Correct
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From which of the following cells is heparin produced?
Your Answer: Mast cells
Explanation:Heparin is a natural highly-sulphated glycosaminoglycan that has anticoagulant functions. It is produced by the body basophils and mast cells.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 49
Correct
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Which is the correct superficial to deep order of structures that would be affected following a knife wound to the lateral aspect of the knee?
Your Answer: skin, fibular collateral ligament, popliteus muscle tendon, lateral meniscus
Explanation:Skin, fibular collateral ligament, popliteus muscle tendon and lateral meniscus is the correct order of structures covering the lateral aspect of the knee joint from a superficial to deep.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 50
Correct
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Which of the following muscles is innervated by the inferior branch of the right recurrent laryngeal nerve?
Your Answer: Posterior cricoarytenoid
Explanation:The posterior cricoarytenoid muscle, which is the sole abductor of the vocal folds, receives its innervation from the inferior laryngeal nerve which is a continuation of the recurrent laryngeal nerve.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 51
Correct
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When a patient is standing erect, pleural fluid would tend to accumulate in which part of the pleural space?
Your Answer: Costodiaphragmatic recess
Explanation:The costo-diaphragmatic recess is the lowest extent of the pleural cavity or sac. Any fluid in the pleura will by gravity accumulate here when a patient is standing erect.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 52
Correct
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The posterior boundary of the carotid triangle is bounded by which of the following muscles?
Your Answer: Sternocleidomastoid
Explanation:The carotid triangle is a portion of the anterior triangle of the neck. It is bounded superiorly by the posterior belly of the digastric muscle, antero-inferiorly by the superior belly of omohyoid and posteriorly by the sternocleidomastoid. The floor is formed by the thyrohyoid, hyoglossus, middle and inferior pharyngeal constrictors and the roof is formed by the skin, superficial fascia, platysma and deep fascia.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 53
Correct
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A 14 year-old girl is found to have haemophilia B. What pathological problem does she have?
Your Answer: Deficiency of factor IX
Explanation:Haemophilia B (also known as Christmas disease) is due to a deficiency in factor IX. Haemophilia A is due to a deficiency in factor VIII.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 54
Correct
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Which of the following muscles winds around the pterygoid hamulus?
Your Answer: Tensor veli palatini
Explanation:The tensor veli palatini tenses the soft palate and by doing so, assists the levator veli palatini in elevating the palate to occlude and prevent entry of food into the nasopharynx during swallowing. It arises by a flat lamella from the scaphoid fossa at the base of the medial pterygoid plate, from the spina angularis of the sphenoid and from the lateral wall of the cartilage of the auditory tube. Descending vertically between the medial pterygoid plate and the medial pterygoid muscle, it ends in a tendon which winds around the pterygoid hamulus, being retained in this situation by some of the fibres of origin of the medial pterygoid muscle. Between the tendon and the hamulus is a small bursa. The tendon then passes medialward and is inserted onto the palatine aponeurosis and the surface behind the transverse ridge on the horizontal part of the palatine bone.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 55
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 56
Correct
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What is the role of factor VII in coagulation?
Your Answer: Initiates the process of coagulation in conjunction with tissue factor
Explanation:The main role of factor VII is to initiate the process of coagulation along with tissue factor (TF). TF is found in the blood vessels and is not normally exposed to the bloodstream. When a vessel is injured tissue factor is exposed to blood and circulating factor VII. Factor VII is converted to VIIa by TF.
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This question is part of the following fields:
- General
- Physiology
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Question 57
Correct
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During a radical mastectomy for advanced breast cancer, the surgeon injured the long thoracic nerve. Which among the following muscles is likely to be affected?
Your Answer: Serratus anterior
Explanation:The long thoracic nerve innervates the serratus anterior muscle which holds the scapula forward and balances the rhomboids and the trapezius muscles which retract the scapula. Injury to this nerve results in a ‘winged scapula’ with a posterior protrusion.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 58
Incorrect
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Which of the following conditions of the breast is most often associated with use of oral contraceptives?
Your Answer: Hypertrophy
Correct Answer: Cyst formation
Explanation:Breast cysts are common and are smooth, firm, mobile lumps that can sometimes be tender. Cysts can also be bilateral and are known to recur in 10% of cases. They are more common in women in the third and fourth decades and most often disappear after menopause. Cysts are filled with fluid from the breast which occurs due to the normal menstrual cycle of a woman. The end of the menstrual cycle causes breast cells to swell. After the menses, the cells shrink and the released fluid disappears. However, in some cases this fluid forms a cyst. Incidence of cysts was also linked to use of oral contraceptives.
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This question is part of the following fields:
- Pathology
- Women's Health
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Question 59
Correct
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After a car accident, a 30-year-old woman is alert and only has minor, superficial injuries. 2 hours later, she becomes unconscious and a CT scan reveals a convex, lens-shaped haemorrhage over the right parietal region. The most likely diagnosis is:
Your Answer: Epidural haematoma
Explanation:Epidural haematomas are usually caused by arterial bleeding, classically due to damage to the middle meningeal artery by a temporal bone fracture. Symptoms develop within minutes to several hours after the injury and consist of increasing headache, decreased level of consciousness, hemiparesis and pupillary dilation with loss of light reactivity. Around 15–20% of epidural hematomas are fatal.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 60
Correct
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A 36-year old gentleman with a history of cough for 4 weeks came to the hospital. Examination revealed multiple lymphadenopathy with splenomegaly. Investigations revealed haemoglobin 11 g/dl, haematocrit 32.4%, mean corpuscular volume (MCV) 93 fl, white blood cell count 63 × 109/l, and platelet count 39 × 109/l; along with characteristic Auer rods on peripheral blood smear. What is the likely diagnosis?
Your Answer: Acute myelogenous leukaemia (AML)
Explanation:AML, or acute myeloid leukaemia is the commonest acute leukaemia affecting adults. increasing in incidence with age. It is a malignancy of the myeloid line of white blood cells. It results in rapid proliferation of abnormal cells, which accumulate in the marrow. Interference with normal cell production leads to a drop in red blood cells, white blood cells and platelets. This causes symptoms such as tiredness, shortness of breath, tendency to bleed or bruise easily and recurrent infections. AML is known to progress quickly and can lead to death in weeks and months if not treated. Leukemic blasts of AML show presence of Auer rods. These are clumps of azurophilic granular material that form needles in the cytoplasm. Composed of fused lysosomes, these contain peroxidase, lysosomal enzymes and crystalline inclusions. Auer rods are classically present in myeloid blasts of M1, M2, M3 and M4 acute leukaemia. They also help to distinguish the preleukemia myelodysplastic syndromes.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 61
Correct
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A 50-year-old woman goes to the doctor complaining of myalgia, muscle cramps, and weakness; she is diagnosed with severe hypokalaemia. Which of the following is the most common cause of hypokalaemia?
Your Answer: Prolonged vomiting
Explanation:Potassium is one of the body’s major ions. Nearly 98% of the body’s potassium is intracellular. The ratio of intracellular to extracellular potassium is important in determining the cellular membrane potential. Small changes in the extracellular potassium level can have profound effects on the function of the cardiovascular and neuromuscular systems. Hypokalaemia may result from conditions as varied as renal or gastrointestinal (GI) losses, inadequate diet, transcellular shift (movement of potassium from serum into cells) and medications. The important causes of hypokalaemia are:
Renal losses: renal tubular acidosis, hyperaldosteronism, magnesium depletion, leukaemia (mechanism uncertain).
GI losses: vomiting or nasogastric suctioning, diarrhoea, enemas or laxative use, ileal loop.
Medication effects: diuretics (most common cause), β-adrenergic agonists, steroids, theophylline, aminoglycosides.
Transcellular shift: insulin, alkalosis.
Severe hypokalaemia, with serum potassium concentrations of 2.5–3 meq/l, may cause muscle weakness, myalgia, tremor, muscle cramps and constipation.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 62
Correct
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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: 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 63
Correct
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Some substances, such as Chromium-51 and Technetium-99, are freely filtered but not secreted or absorbed by the kidney. In these cases, their clearance rate is equal to:
Your Answer: Glomerular filtration rate
Explanation:If a substance passes through the glomerular membrane with perfect ease, the glomerular filtrate contains virtually the same concentration of the substance as does the plasma and if the substance is neither secreted nor reabsorbed by the tubules, all of the filtered substance continues on into the urine. Glomerular filtration rate (GFR) describes the flow rate of filtered fluid through the kidney.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 64
Correct
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A suspected recreational drug user was brought to the Emergency department in an unconscious state, and was found to be hypoventilating. Which of the following set of arterial blood gas analysis report is most consistent with hypoventilation as the primary cause? pH, pa(CO2) (mmHg), pa(O2) (mmHg).
Your Answer: 7.28, 55, 81
Explanation:Hypoventilation (or respiratory depression) causes an increase in carbon dioxide (hypercapnia) and respiratory acidosis. It can result due to drugs such as alcohol, benzodiazepines, barbiturates, opiates, mechanical conditions or holding ones breath. Strong opioids such as heroin and fentanyl are commonly implicated and can lead to respiratory arrest. In recreational drug overdose, acute respiratory acidosis occurs with an increase in p(CO2) over 45 mm Hg and acidaemia (pH < 7.35)
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 65
Incorrect
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A week after a renal transplant the patient received antilymphocyte globulins. Shortly after she developed fever and hypotension. Which of the following mechanisms is involved in this response?
Your Answer: Type II hypersensitivity
Correct Answer: Type III hypersensitivity
Explanation:Type III hypersensitivity is characterized by soluble immune complexes which are aggregations of IgG and IgM antibodies with antigens that deposit in different tissues e.g. the skin, joints, kidneys. They can then trigger an immune response by activating the complement cascade. This reaction can take hours to develop and examples include: immuno-complex glomerulonephritis, rheumatoid arthritis, SLE, subacute bacterial endocarditis, arthus reaction and serum sickness.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 66
Correct
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In a splenectomy procedure, special care is emphasized on the preservation of the tail of the pancreas that is closely associated with the spleen to avoid post operative pancreatic fistula. As a general surgeon conducting a splenectomy where are you most likely to find the tail of the pancreas in the abdominal cavity?
Your Answer: Splenorenal ligament
Explanation:The tail of the pancreas is the only intraperitoneal part of the pancreas and is found contained in the splenorenal ligament of the peritoneal cavity. The splenorenal ligament is derived from the peritoneum where the wall of the general peritoneal cavity connects to the omental bursa between the spleen and the left kidney. This ligament contains the splenic vessels and the tail of the pancreas.
The gastrocolic ligament stretches from the greater curvature of the stomach to the transverse colon, connecting the two.
The gastrosplenic ligament is derived from the greater omentum and is the structure that connects the stomach to the hilum of the spleen. The gastrosplenic ligament continues from the splenic flexure of the colon to the diaphragm and acts as a support to the spleen.
The transverse colon is connected to the abdominal wall by the mesocolon ligament.
The falciform ligament on the other hand, attaches the liver to the ventral wall of the abdomen.
The hepatoduodenal ligament connects the porta hepatis of the liver to the superior part of the duodenum.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 67
Correct
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Calculate the cardiac output in an adult male with the following parameters:
Heart rate 70 beats/min
Arterial [O2] 0.24 ml O2/min
Venous [O2] 0.16 ml O2/mi
Whole body O2 consumption 500 ml/min
Pulmonary diastolic pressure 15 mmHg
Pulmonary systolic pressure 25 mmHg
Wedge pressure 5 mmHg.Your Answer: 6.25 l/min
Explanation:As per Fick’s principle, VO2 = (CO × CAO2) – (CO × CVO2) where VO2 = oxygen consumption, CO = cardiac output, CAO2 = oxygen concentration of arterial blood and CVO2 = oxygen concentration of venous blood. Thus, CO = VO2/CAO2– CVO2, CO = 500/0.24 – 0.16, CO = 500/0.8, CO = 6.25 l/min.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 68
Correct
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Which among the following vertebrae marks the lowest extent of the superior mediastinum?
Your Answer: Fourth thoracic
Explanation:The superior mediastinum lies between the manubrium anteriorly and the upper vertebrae of the thorax posteriorly. Below, it is bound by a slightly oblique plane that passes backward from the sternal angle to the lower part of the body of T4 and laterally by the pleura.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 69
Incorrect
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Which of the following two cerebral veins join up to form the great cerebral vein, otherwise also known as the great vein of Galen?
Your Answer: Inferior sagittal sinuses
Correct Answer: Internal cerebral veins
Explanation:The great vein of Galen or great cerebral vein, is formed by the union of the internal cerebral veins and the basal veins of Rosenthal. This vein curves upwards and backwards along the border of the splenium of the corpus callosum and eventually drains into the inferior sagittal sinus and straight sinus at its anterior extremity.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 70
Correct
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The passage of leukocytes through the wall of the blood vessels is best described by which of the following terms?
Your Answer: Diapedesis
Explanation:The steps involved in leukocyte arrival and function are:
1. margination: cells migrate from the centre to the periphery of the vessel
2. rolling: selectins are upregulated on the vessel walls
3. adhesion: upregulation of the adhesion molecules ICAM and VCAM on the endothelium interact with integrins on the leukocytes, interaction of these results in adhesion
4. diapedesis and chemotaxis: diapedesis is the transmigration of the leukocyte across the endothelium of the capillary and towards a chemotactic product
5. phagocytosis: engulfing the offending substance/cell.
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This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
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Question 71
Correct
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The primary motor cortex is located in the:
Your Answer: Precentral gyrus
Explanation:The primary motor cortex is located in the dorsal part of the precentral gyrus and the anterior bank of the central sulcus. The precentral gyrus lies anterior to the postcentral gyrus and is separated from it by a central sulcus. Its anterior border is the precentral sulcus, while inferiorly it borders to the lateral fissure (Sylvian fissure).
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This question is part of the following fields:
- Neurology
- Physiology
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Question 72
Correct
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A 27-year-old female was admitted due to severe dehydration. The patient also complained of chest tightness, thus an ECG was requested. The ECG strip showed an isoelectric ST segment, upright T wave, with prominent U waves. What is the most likely electrolyte abnormality responsible for these ECG tracing?
Your Answer: Hypokalaemia
Explanation:U waves are prominent if it is >1-2mm or 25% of the height of the T wave. Abnormally prominent U waves are characteristically seen in severe hypokalaemia.
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This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
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Question 73
Correct
-
A surgeon trainee is assisting in an operation to ligate the ductus arteriosus. The consultant supervising explains that caution is required when placing a clamp on the ductus to avoid injury to an important structure immediately dorsal to it. To which structure is the consultant referring?
Your Answer: Left recurrent laryngeal nerve
Explanation:The left recurrent laryngeal nerve branches off the vagus and wraps around the aorta, posterior to the ductus arteriosus/ligamentum arteriosum from whence it courses superiorly to innervate the laryngeal muscles.
Accessory Hemiazygous vein is on the left side of the body draining the posterolateral chest wall and emptying blood into the azygos vein.
The left internal thoracic artery is branch of the left subclavian artery supplying blood to the anterior wall of the thorax.
Left phrenic nerve is lateral to the vagus nerve.
Thoracic duct: is behind the oesophagus, coursing between the aorta and the azygos vein in the posterior chest.
Right recurrent laryngeal nerve: loops around the right subclavian artery and is not in danger in this procedure.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 74
Correct
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Which of the following arteries, if ligated, will most likely affect blood supply to the pancreas?
Your Answer: Superior mesenteric
Explanation:The pancreas is a glandular organ in the body that produces important hormones such as insulin and glucagon. Its blood supply is from branches of the coeliac artery, superior mesenteric artery and the splenic artery. These are the arteries that if ligated, would affect blood supply to the pancreas.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 75
Correct
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A 65-year old man, known with Type 2 diabetes and chronic renal failure, is likely to eventually present with which of the following conditions?
Your Answer: Secondary hyperparathyroidism
Explanation:When the parathyroid glands secrete excess parathyroid hormone (PTH) in response to hypocalcaemia, it is known as Secondary hyperparathyroidism and is often seen in patients with renal failure. In chronic renal failure, the kidneys fail to excrete adequate phosphorus and also fail to convert enough vitamin D to its active form. This leads to formation of insoluble calcium phosphate in the body which ultimately causes hypocalcaemia. The glands then undergo hyperplasia and hypertrophy leading to secondary hyperparathyroidism. Symptoms include bone and joint pains, along with limb deformities. The raised PTH also results in pleiotropic effects on blood, the immune system and nervous system.
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This question is part of the following fields:
- Endocrine
- Pathology
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Question 76
Correct
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A patient with this type of tumour is advised to follow up regularly for monitoring of tumour size as there is a strong correlation with malignant potential and tumour size. Which of the following is the most likely tumour in this patient?
Your Answer: Renal adenocarcinoma
Explanation:The distinction between a benign renal adenoma and renal adenocarcinoma is commonly made on the basis of size. Tumours less than 2 cm in size rarely become malignant as opposed to those greater than 3 cm.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 77
Correct
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Tumours derived from all three germ-cell layers in new-borns usually occur in which of the following sites?
Your Answer: Sacrococcygeal area
Explanation:A teratoma is a tumour with tissue or organ components resembling normal derivatives of more than one germ layer. It is derived from all three cell layers. The most common location of teratoma in new-born infants is in the sacrococcygeal area.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 78
Incorrect
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Calculate the cardiac stroke volume of a patient whose oxygen consumption (measured by analysis of mixed expired gas) is 300 ml/min, arterial O2 content is 20 ml/100 ml blood, pulmonary arterial O2 content is 15 ml/100 ml blood and heart rate is 60/min.
Your Answer: 1 ml
Correct Answer: 100 ml
Explanation:By Fick’s principle, VO2 = Q × (CA (O2) − CV (O2)) where VO2 = O2 consumption, Q = cardiac output and CA(O2) and CV(O2) are arterial and mixed venous O2 content respectively. Thus, in the given problem, 300 ml O2/min = Q × (20−15) ml O2/100 ml. Thus, Q = 6000 ml blood/min. Then, we can calculate stroke volume by dividing the cardiac output with heart rate. Thus, stroke volume = 6000 ml/min divided by 60/min stroke volume = 100 ml.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 79
Correct
-
An amateur body-builder complains of increasing pain in his right shoulder after a few days of intense training. A surgeon aspirates clear fluid from his subdeltoid region. What's the most likely diagnosis?
Your Answer: Bursitis
Explanation:Bursae are potential cavities that contain synovial fluid, found in areas where friction occurs. Their function is to minimise friction and facilitate movement. Bursitis is the inflammation of one or more bursae, and they can occur in the shoulder, elbow, knee, ischium, amongst other joints. Acute bursitis can appear after strenuous exercise or activity, and chronic bursitis can develop following previous bursitis or trauma. Acute bursitis causes pain, tenderness, and swelling.
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This question is part of the following fields:
- Orthopaedics
- Pathology
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Question 80
Correct
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Under normal conditions, what is the major source of energy of cardiac muscles?
Your Answer: Fatty acids
Explanation:Under basal conditions, most of the energy needed by cardiac muscle for metabolism is derived from fats (60%), 35% by carbohydrates, and 5% by ketones and amino acids. However, after intake of large amounts of glucose, lactate and pyruvate are mainly used. During prolonged starvation, fat acts as the primary source. 50% of the used lipids are sourced from circulating fatty acids.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 81
Correct
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A 45-year-old woman was brought to the emergency department due to fever and chills. She has a history of recurrent UTI and complains of dysuria and urinary frequency. Urinary white blood cell count is >200 cell/high power field. If urine culture is performed, what is the most likely organism that will grow?
Your Answer: Escherichia coli
Explanation:The pathogen that most likely causes recurrent urinary tract infection in young women are E. coli, Enterococcus and Staphylococcus saprophyticus.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 82
Correct
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A 20 year old is brought to the A&E after he fell from a moving cart. The boy has sustained blunt abdominal injury, and the there is a possibility of internal bleeding as the boy is in shock. An urgent exploratory laparotomy is done in the A&E theatre. On opening the peritoneal cavity, the operating surgeon notices a torn gastrosplenic ligament with a large clot around the spleen. Which artery is most likely to have been injured in this case?
Your Answer: Short gastric
Explanation:The short gastric arteries branch from the splenic artery near the splenic hilum to travel back in the gastrosplenic ligament to supply the fundus of the stomach. Therefore, these may be injured in this case.
The splenic artery courses deep to the stomach to reach the hilum of the spleen. It doesn’t travel in the gastrosplenic ligament although it does give off branches that do.
The middle colic artery is a branch of the superior mesenteric artery that supplies the transverse colon.
Gastroepiploic artery is the largest branch of the splenic artery that courses between the layers of the greater omentum to anastomose with the right gastroepiploic.
Left gastric artery, a branch of the coeliac trunk. It supplies the left half of the lesser curvature.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 83
Correct
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Which of the following conditions is characterized by generalised oedema due to effusion of fluid into the extracellular space?
Your Answer: Anasarca
Explanation:Anasarca (or ‘generalised oedema’) is a condition characterised by widespread swelling of the skin due to effusion of fluid into the extracellular space. It is usually caused by liver failure (cirrhosis of the liver), renal failure/disease, right-sided heart failure, as well as severe malnutrition/protein deficiency.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 84
Correct
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A patient who underwent emergency appendicectomy complains of having numbness (paraesthesia) of the skin at the pubic region. Which nerve was most likely injured in the operation?
Your Answer: Iliohypogastric
Explanation:The iliohypogastric nerve comes from L1 and emerges from the upper part of the lateral border of the psoas major. It then crosses obliquely in front of the quadratus lumborum to the iliac crest where it perforates the posterior part of transversus abdominis and divides between that muscle and the internal oblique into a lateral and an anterior cutaneous branch. This provides sensory innervation to the skin of the lower abdominal wall, upper hip and upper thigh.
The genitofemoral nerve also comes from the lumbar plexus that innervates the skin of the anterior scrotum or labia majora and upper medial thigh.
The subcostal nerve is the ventral primary ramus of T12 providing sensory innervation to the anterolateral abdominal wall in an area superior to the pubic region.
A spinal nerve owing to their deep location would not have been injured in the procedure.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 85
Correct
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A histopathological analysis of a specimen showed loss of individual cell structure with karyorrhexis and fragmentation. The overall integrity of the tissue structure is preserved. This is typical of which of the following pathologies?
Your Answer: Viral hepatitis
Explanation:Viral infections will cause necrosis of the hepatocytes with characteristic changes of karyorrhexis and cell fragmentation.
Brown atrophy of the heart is due to accumulation of lipofuscin in the myocardium.
Tissue destruction associated with transplant rejection leads to widespread loss of structural integrity.
Single cell necrosis is not characteristically seen in chronic alcoholic liver.
Barbiturate overdose will result in hypertrophy of the smooth endoplasmic reticulum.
Carcinoma insitu will cause dysplastic cells without the overall structural integrity being disrupted.
Atrophy is due to apoptosis with ordered cellular fragmentation and phagocytosis and will not induce an inflammatory process unlike necrosis.
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This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
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Question 86
Correct
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During thyroidectomy, the recurrent laryngeal nerves are vulnerable to injury. Which of the following muscles will not be affected in cases where the recurrent laryngeal nerve is severed?
Your Answer: Cricothyroid
Explanation:All muscles of the larynx are supplied by the recurrent laryngeal nerve except for the cricothyroid which is supplied by the vagus nerve.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 87
Correct
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An infant, 5 weeks and 6 days old born with a large sub-aortic ventricular septal defect, is prepared for pulmonary artery banding through a left thoracotomy (the child is not fit for a surgical closure). The surgeon initially passes his index finger immediately behind two great arteries in the pericardial sac to mobilise the great arteries in order to pass the tape around the pulmonary artery. Into which space is the surgeon's finger inserted?
Your Answer: Transverse pericardial sinus
Explanation:Cardiac notch: is an indentation on the left lung of the heart.
Coronary sinus: a venous sinus on the surface of the heart (the posterior aspect) that receives blood from the smaller veins that drain the heart.
Coronary sulcus: a groove on the heart between the atria and ventricles.
Transverse pericardial sinus: located behind the aorta and pulmonary trunk and anterior to the superior vena cava.
Oblique pericardial sinus: located behind the left atrium. Accessed from the inferior side (or the apex) of the heart upwards.
Horizontal pericardial sinus: this is a made-up term.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 88
Correct
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An episiotomy is indicated for a woman during a difficult vaginal delivery. Whilst the registrar was performing this procedure she made a median cut too far through the perineal body cutting the structure immediately posterior. Which structure is this?
Your Answer: External anal sphincter
Explanation:An episiotomy is an incision that is made whenever there is a risk of a tear during vaginal deliver. A posterolateral incision, as opposed to a median incision is preferred. Of the options given, the external anal sphincter lies right posterior to the perineal body. The sacrospinous and the sacrotuberous ligaments are deep in the perineum that they should not be involved in this.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 89
Correct
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A 7-year-old boy with facial oedema was brought to the hospital by his parents. Renal function is normal and urinalysis revealed the presence of a profound proteinuria. Which of the following is the most probable cause of these findings?
Your Answer: Minimal-change disease
Explanation:Minimal-change disease (MCD) refers to a histopathologic glomerular lesion, typically found in children, that is almost always associated with nephrotic syndrome. The most noticeable symptom of MCD is oedema, which can develop very rapidly. Due to the renal loss of proteins muscle wasting and growth failure may be seen in children. Renal function is usually not affected and a proteinuria of more than 40 mg/h/m2 is the only abnormal finding in urinalysis.
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This question is part of the following fields:
- Pathology
- Renal
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Question 90
Correct
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Which of the following is responsible for the activation of pepsinogen released in the stomach?
Your Answer: Acid pH and pepsin
Explanation:Pepsinogen is the inactive precursor of pepsin. Once secreted, it comes in contact with hydrochloric acid and pepsin, previously formed, and undergoes cleavage to form active pepsin.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 91
Correct
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An abdominal aortogram shows occlusion of the inferior mesenteric artery. Which of the following segments of bowel is most likely to have preserved arterial supply?
Your Answer: Caecum
Explanation:The inferior mesenteric artery supplies blood to the end of the transverse colon and all distal structures in the gastrointestinal tract i.e. splenic flexure, descending colon, sigmoid colon and rectum would all be deprived of blood if it were occluded. The caecum receives blood from the superior mesenteric artery so it would not be affected.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 92
Correct
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The pterion is clinically significant as it marks an area of weakness on the skull. What structure lies beneath it?
Your Answer: Anterior branches of the middle meningeal artery
Explanation:The pterion is the area where four bones, the parietal, frontal, greater wing of sphenoid and the squamous part of the temporal bone meet. It overlies the anterior branch of the middle meningeal artery on the internal aspect of the skull. The pterion is the weakest part of the skull. Slight trauma to this region can cause extradural hematoma.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 93
Correct
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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: 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 94
Correct
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A 76-year-old man with a urinary tract obstruction due to prostatic hyperplasia develops acute renal failure. Which of the following physiological abnormalities of acute renal failure will be most life threatening for this patient?
Your Answer: Acidosis
Explanation:Acute renal failure (ARF) is a rapid loss of renal function due to damage to the kidneys, resulting in retention of nitrogenous (urea and creatinine) and non-nitrogenous waste products that are normally excreted by the kidney. This accumulation may be accompanied by metabolic disturbances, such as metabolic acidosis and hyperkalaemia, changes in body fluid balance and effects on many other organ systems. Metabolic acidosis and hyperkalaemia are the two most serious biochemical manifestations of acute renal failure and may require medical treatment with sodium bicarbonate administration and antihyperkalaemic measures. If not appropriately treated these can be life-threatening. ARF is diagnosed on the basis of characteristic laboratory findings, such as elevated blood urea nitrogen and creatinine, or inability of the kidneys to produce sufficient amounts of urine.
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This question is part of the following fields:
- Physiology
- Renal
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Question 95
Correct
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A 41 year old women presents with a history of carcinoma involving the right breast with enlarged axillary nodes on the same side. She underwent mastectomy and axillary node clearance. These were sent for histopathological examination. They showed no signs of metastasis. What could be cause of this enlargement in the lymph nodes?
Your Answer: Sinus histiocytosis
Explanation:Sinus histiocytosis also referred to as reticular hyperplasia, refers to the enlargement, distention and prominence of the sinusoids of the lymph nodes. This is a non-specific form of hyperplasia characteristically seen in lymph nodes that drain tumours. The endothelial lining of the lymph node becomes markedly hypertrophied, along with an increase in the number of macrophages which results in the distortion, distention and enlargement of the sinus. In this scenario there is no evidence that an infection or another malignancy could account for the enlargement. Paracortical lymphoid hyperplasia is caused by an immune response.
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This question is part of the following fields:
- Inflammation & Immunology; Female Health
- Pathology
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Question 96
Correct
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Which of the following organelles have the capacity to regenerate and spontaneously replicate?
Your Answer: Mitochondrion
Explanation:A mitochondria is a membrane bound organelle found in eukaryotic cells. They are called the powerhouse of the cell and are the place where ATP is formed from energy generated through metabolism. They are capable of replication as well as repair and regeneration.
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This question is part of the following fields:
- General
- Physiology
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Question 97
Correct
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A football player sustained an injury to his ankle. The wound went through the skin, subcutaneous tissue and flexor retinaculum. Which other structure passing under the retinaculum may be injured?
Your Answer: Tibial nerve
Explanation:The flexor retinaculum is immediately posterior to the medial malleolus. The structures that pass under the flexor retinaculum from anterior to posterior are: tendon of the tibialis posterior, flexor digitorum longus, posterior tibial artery (and vein), tibial nerve and tendon of flexor hallucis longus. The tibial nerve is the only one which lies behind the flexor retinaculum.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 98
Correct
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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: 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 99
Correct
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Which nerve lies immediately medial to the psoas major muscle?
Your Answer: Obturator
Explanation:The obturator nerve is formed from the ventral divisions of the 2nd, 3rd and 4th lumbar nerves. It courses through the fibres of the psoas major and emerges from the medial border near the pelvic brim.
The iliohypogastric nerve comes from the first lumbar nerve and emerges from the upper part of the lateral border of psoas major.
The ilioinguinal nerve arises with the iliohypogastric nerve from the first lumbar nerve and also emerges from the lateral border of the psoas major muscle.
The lateral femoral cutaneous nerve comes from the posterior division of the 2nd and 3rd lumbar nerves to emerge from the lateral border of the psoas major muscle near its middle.
The femoral nerve also arises from the dorsal divisions, but of the 2nd, 3rd and 4th lumbar nerves and courses through the muscle fibres to emerge at the lower part of the lateral border.
The coccygeal nerve doesn’t arise from the lumbar plexus but from the sacral plexus.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 100
Correct
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Muscles and tendons in the planter region of the foot mainly take blood supply from:
Your Answer: Posterior tibial artery
Explanation:The posterior tibial artery is the main source of blood supply to the posterior compartment of the leg.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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SESSION STATS - PERFORMANCE PER SPECIALTY
