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Question 1
Correct
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A 54-year-old woman with amyotrophic lateral sclerosis is diagnosed with respiratory acidosis. The patient’s renal excretion of potassium would be expected to:
Your Answer: Fall, since tubular secretion of potassium is inversely coupled to acid secretion
Explanation:Respiratory acidosis is a medical emergency in which decreased ventilation (hypoventilation) increases the concentration of carbon dioxide in the blood and decreases the blood’s pH (a condition generally called acidosis). Secretion of acid and potassium by the renal tubule are inversely related. So, increased excretion of H+ during renal compensation for respiratory acidosis will result in decreased secretion (or increased retention) of potassium ions, with the result that the body’s potassium store rises. An increase in K+ excretion would be associated with renal compensation for respiratory alkalosis. The filtered load of K+depends only on K+ plasma concentration and glomerular filtration rate, not on plasma pH.
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This question is part of the following fields:
- Physiology
- Renal
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Question 2
Correct
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A biopsy is performed on a 67-year-old-man with testicular seminoma; it reveals that the tumour affects the tunica vaginalis. The tumour stage in this case is:
Your Answer: T2
Explanation:The primary tumour staging for testicular seminoma is as follows, according to AJCC guidelines:
Tis: intratubular germ cell neoplasia (carcinoma in situ)
T1: tumour limited to testis/epididymis without vascular or lymphatic invasion; the tumour can invade into the tunica albuginea but not the tunica vaginalis
T2: tumour limited to testis/epididymis with vascular or lymphatic invasion or tumour extending through the tunica albuginea with involvement of the tunica vaginalis
T3: tumour invading the spermatic cord, with or without vascular/lymphatic invasion
T4: tumour invading the scrotum, with or without vascular/lymphatic invasion.
According to these guidelines, the tumour in this case has a T2 stage.
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This question is part of the following fields:
- Pathology
- Urology
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Question 3
Correct
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A neonate is diagnosed with cryptorchidism of the right side (undescended testis). Which is the LEAST likely place to find the testis?
Your Answer: Perineum
Explanation:Embryologically the testes are retroperitoneal structures in the posterior abdominal wall, attached to the anterolateral abdominal wall by the gubernaculum. The gubernaculum ‘pulls’ the testes through the deep inguinal ring, inguinal canal and superficial inguinal ring and over the pelvic brim. The gubernaculum is preceded by the processus vaginalis that is derived from the peritoneum anterior to the testes. The processus vaginalis pushes the muscle and fascial layers. These eventually make up the canal and the spermatic cord, into the scrotum. The gubernaculum persists as the scrotal ligament while part of the processus vaginalis remains as a bursa-like sac i.e. the tunica vaginalis testes. The testes therefore could be caught in any one of these places along its path of descending. The testes are never in the perineum.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 4
Incorrect
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An 18 year-old with an iron deficient diet was prescribed an iron supplement by her GP. Lack of iron often results in:
Your Answer: Pernicious anaemia
Correct Answer: Hypochromic anaemia
Explanation:Iron deficiency anaemia is the most common type of anaemia. It can occur due to deficiency of iron from decreased intake, increased loss or inadequate absorption. An MCV less than 80 will indicated iron deficiency anaemia. On the smear the RBCs will be microcytic hypochromic and will also show poikilocytosis. Iron profile tests are important to make a diagnosis. Clinically the patient will be pale and lethargic.
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This question is part of the following fields:
- General
- Physiology
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Question 5
Incorrect
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The mechanism of action of streptokinase involves:
Your Answer: Direct lysis of the clot
Correct Answer: Direct conversion of plasminogen to plasmin
Explanation:Streptokinase is an enzyme that is produced by group A beta haemolytic streptococcus and is an effective and cost efficient method for the dissolution of a clot used in cases of MI and pulmonary embolism. It works by directly converting plasminogen to plasmin which breaks down the blood components in the clot and fibrin, dissolving the clot. Streptokinase is a bacterial product and thus the body will develop immunity against it.
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This question is part of the following fields:
- General
- Physiology
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Question 6
Correct
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In order to arrest sudden bleeding during pericardiectomy that started after accidental injury to a major vasculature in the pericardium; the surgeon inserted his left index finger through the transverse pericardial sinus, pulled forward on the two large vessels lying ventral to his finger, and compressed these vessels with his thumb to control the bleeding. Which vessels were these?
Your Answer: Pulmonary trunk and aorta
Explanation:Transverse pericardial sinus: located behind two great vessels (aorta and pulmonary trunk) and in front of the superior vena cava and is accessed from above as in this case. The brachiocephalic trunk is located above the pericardium and the right pulmonary artery is above the pericardial reflections.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 7
Incorrect
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A 45 year old female had a stroke and was diagnosed with a homonymous hemianopsia. Which of the following structures was likely affected?
Your Answer: Abducent nucleus
Correct Answer: Optic radiation
Explanation:Hemianopia or hemianopsia, is the loss of vision of half of the eye or loss of half the visual field. Homonymous hemianopia is the loss of vision or blindness on half of the same side of both eyes (visual field) – either both lefts of the eyes or both rights of the eyes. This condition is mainly caused by cerebrovascular accidents like a stroke that affects the optic radiation.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 8
Correct
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A man had noticed weakness in his left arm causing flexion of the elbow and supination of the forearm. Which nerve in this case was injured?
Your Answer: Musculocutaneous
Explanation:The musculocutaneous nerve supplies the biceps brachii and the brachialis muscles. The first one flexes the elbow and the shoulder. It is also involved in supination. The brachialis muscle flexes the forearm. The injury to the musculocutaneous nerve results in paralysis of these muscles.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 9
Correct
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A young lady visited a doctor with complaints of fever and a dull, continuous pain in the right lumbar region for 6 days. On, enquiry, she recalled passing an increasing number of stools with occasional blood in last few months. Lower gastrointestinal endoscopic biopsy was taken 5 cm proximal to ileocaecal valve which showed transmural inflammation with several granulomas. Tissue section showed the absence of acid-fast bacillus. She denies any history of travel and her stool cultures were negative. What is the likely diagnosis?
Your Answer: Crohn’s disease
Explanation:Crohn’s disease is a chronic, inflammatory disease that can affect any part of the gastrointestinal tract but is usually seen in the distal ileum and colon. It is transmural and symptoms include chronic diarrhoea, abdominal pain, fever, anorexia and weight loss. On examination, there is usually abdominal tenderness with a palpable mass or fullness seen occasionally. Rectal bleeding is uncommon (except in isolated colonic involvement) which manifests like ulcerative colitis. Differential diagnosis includes acute appendicitis or intestinal obstruction. 25%-33% patients also have perianal disease in the form of fissure or fistulas.
Extra intestinal manifestations predominate in children, and include: arthritis, pyrexia, anaemia or growth retardation. Histologically, the disease shows crypt inflammation and abscesses initially, which progress to aphthoid ulcers. These eventually develop into longitudinal and transverse ulcers with interspersed mucosal oedema, leading to the characteristic ‘cobblestoned appearance’. Transmural involvement leads to lymphoedema and thickening of bowel wall and mesentery, leading to extension of mesenteric fat on the serosal surface of bowel and enlargement of mesenteric nodes. There can also be hypertrophy of the muscularis mucosae, fibrosis and stricture formation, which can cause bowel obstruction.
Abscesses are common and the disease can also leas to development of fistulas with various other organs, anterior abdominal wall and adjacent muscles. Pathognomonic non-caseating granulomas are seen in 50% cases and they can occur in nodes, peritoneum, liver, and in all layers of the bowel wall. The clinical course does not depend on the presence of granulomas. There is sharp demarcation between the diseased and the normal bowel (skip areas).
35% cases show only the ileal involvement, whereas in 45% cases, both the ileum and colon are involved with a predilection for right side of colon. 20% cases show only colonic involvement, often sparing the rectum (unlike ulcerative colitis). In occasional cases, there is jejunoileitis – involvement of the entire small bowel. The stomach, duodenum and oesophagus are rarely involved, although there has been microscopic evidence of disease involving the gastric antrum in younger patients. The affected small bowel segments show increased rick of cancer. Moreover, patients with colonic disease show a long-term risk of cancer similar to that seen in ulcerative colitis.
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This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
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Question 10
Incorrect
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One of the following structures is contained in the anterior compartment of the lower leg. Which is it?
Your Answer: The fibular artery
Correct Answer: Extensor hallucis muscle
Explanation:The lower leg is made up of four fascial compartments separated from one another by septa that contain the muscles of the lower leg. The four compartments are ; anterior, lateral, deep posterior and superficial posterior compartments.
These are the compartments and there contents:
i) Anterior compartment: Tibialis anterior muscle, extensor hallucis longus muscle, extensor digitorum longus muscle, peroneus tertius muscles, deep fibular nerve and anterior tibial blood vessels
ii) Lateral compartment: Fibularis longus muscle, brevis muscles and superficial fibular nerve
iii) Deep posterior compartment: Tibialis posterior m., flexor hallucis longus m., flexor digitorum longus m. ,popliteus m. , tibial nerve, posterior tibial artery and posterior tibial vessels such as the fibular artery.
iv) Superficial posterior compartment: Gastrocnemius m., soleus m., plantaris m., medial sural cutaneous nerve
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 11
Incorrect
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Which of the following cells would be increased in a patient suffering from a hydatid cyst in the liver?
Your Answer: Neutrophils
Correct Answer: Eosinophils
Explanation:Eosinophils are granulocytes that respond to parasitic infections. They are also involved in allergy response and asthma. They contain granules which stain red with Romanowsky’s method and contain peroxidase, Rnase, Dnase, histamine, lipase and major basic proteins that are toxic to the parasite as well as the hosts tissue. They are about 1-5% of the total WBC population and persist in the blood for 6-12 hours.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 12
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: normal FEV1, 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. Which of the following is most accurate about his residual volume?
Your Answer: Cannot be measured directly with a spirometer
Explanation:Residual volume is the air left in the lungs after maximal expiration is done. Thus, this is not a part of vital capacity and cannot be measured with a spirometer directly. It can be measured by the methods such as body plethysmography or inert gas dilution. Expiratory reserve volume is vital capacity minus inspiratory capacity. Resting volume of lungs is he sum of residual volume and expiratory reserve volume. Lungs recoil inward until the recoil pressure becomes zero, which corresponds to a volume significantly lower than residual volume.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 13
Correct
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Which of the following is likely to induce secretion of glucagon?
Your Answer: Low serum concentration of glucose
Explanation:The most potent stimulus for secretion of glucagon is hypoglycaemia whereas hyperglycaemia is a stimulus for insulin release. Glucagon secretion also occurs in response to high levels of amino acids. Somatostatin inhibits glucagon secretion. Parasympathetic stimulation increases pancreatic acinar secretion, but not of α-cells.
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This question is part of the following fields:
- Endocrinology
- Physiology
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Question 14
Incorrect
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Where do the cells belonging to the mononuclear phagocyte system originate?
Your Answer: Thymus
Correct Answer: Bone marrow
Explanation:The macrophage originates from a committed bone marrow stem cell. It is called the pluripotent hematopoietic stem cell. This differentiates into a monoblast and then into a promonocyte and finally matures into a monocyte. When called upon they leave the bone marrow and enter into the circulation. Upon entering the tissue they transform into macrophages. Tissue macrophages include: Kupffer cells (liver), alveolar macrophages (lung), osteoclasts (bone), Langerhans cells (skin), microglial cells (central nervous system), and possibly the dendritic immunocytes of the dermis, spleen and lymph nodes.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 15
Correct
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Regarding innervation to the peroneus brevis muscle:
Your Answer: Could be damaged by a fracture of the neck of the fibula
Explanation:The peroneus brevis is supplied by the fourth and fifth lumbar and first sacral nerves through the superficial peroneal nerve which is one of the two terminal branches of the common peroneal nerve. The common peroneal nerve winds around the neck of the fibula and can be injured in cases of fractured neck of fibula.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 16
Correct
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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 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 17
Correct
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Depression of the normal coagulation system and excessive bleeding after surgery can occur in which of the following medical conditions?
Your Answer: Liver disease
Explanation:As most of the coagulation factors are synthesized in the liver, liver diseases like hepatitis or cirrhosis will depress the coagulation system. Vitamin K deficiency can also decrease the production of vitamin K dependent coagulation factors VII, XI, X and prothrombin.
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This question is part of the following fields:
- General
- Physiology
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Question 18
Correct
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What is the nerve supply of the muscle that is inserted onto the crest of the lesser tubercle of the humerus?
Your Answer: Lower subscapular
Explanation:The muscle is the subscapularis muscle which is supplied by the lower subscapular nerve.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 19
Incorrect
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Which of the given options best describes the metabolic changes which occur following a severe soft tissue injury sustained after a PVA?
Your Answer: Inhibition of gluconeogenesis
Correct Answer: Mobilisation of fat stores
Explanation:The following metabolic responses occur following trauma as part of a coping mechanism for the additional stress. These include acid base changes (metabolic acidosis or alkalosis), decrease urine output and osmolality, reduced basal metabolic rate (BMR), gluconeogenesis with amino acid breakdown and shunting, hyponatraemia as a result of impaired functioning of sodium pumps, hypoxic injury, coagulopathies, decreased immunity, increase extracellular fluid and hypovolemic shock, increase permeability leading to oedema, break down and mobilization of fat reserves, pyrexia and reduced circulating levels of albumin.
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This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
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Question 20
Correct
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A 76-year-old woman is diagnosed with diabetes mellitus after a urine test revealed she has glucosuria. Glucosuria may occur due to inadequate glucose reabsorption at:
Your Answer: Proximal convoluted tubule
Explanation:Glucose is reabsorbed almost 100% via sodium–glucose transport proteins (apical) and GLUT (basolateral) in the proximal convoluted tubule. Glycosuria or glucosuria is a condition of osmotic diuresis typical in those suffering from diabetes mellitus. Due to a lack of insulin, plasma glucose levels are above normal. This leads to saturation of receptors in the kidneys and glycosuria usually at plasma glucose levels above 11 mmol/l. Rarely, glycosuria is due to an intrinsic problem with glucose reabsorption within the kidneys (such as Fanconi syndrome), producing a condition termed renal glycosuria.
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This question is part of the following fields:
- Physiology
- Renal
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Question 21
Correct
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The Henderson–Hasselbalch equation describes the derivation of pH as a measure of acidity. According to this equation, the buffering capacity of the system is at maximum when the number of free anions compared with undissociated acid is:
Your Answer: Equal
Explanation:In 1908, Lawrence Joseph Henderson wrote an equation describing the use of carbonic acid as a buffer solution. Later, Karl Albert Hasselbalch re-expressed that formula in logarithmic terms, resulting in the Henderson–Hasselbalch equation. The equation is also useful for estimating the pH of a buffer solution and finding the equilibrium pH in acid–base reactions. Two equivalent forms of the equation are: pH = pKa + log10 [A–]/[HA] or pH = pKa + log10 [base]/[acid]. Here, pKa is − log10(Ka) where Ka is the acid dissociation constant, that is: pKa = –log10(Ka) = –log10 ([H3 O+][A–]/[HA]) for the reaction: HA + H2 O ≈ A– + H3 O+ In these equations, A– denotes the ionic form of the relevant acid. Bracketed quantities such as [base] and [acid] denote the molar concentration of the quantity enclosed. Maximum buffering capacity is found when pH = pKa or when the number of free anions to undissociated acid is equal and buffer range is considered to be at a pH = pKa ± 1.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 22
Incorrect
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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: Addison’s disease
Correct 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 23
Correct
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The pattern of drainage of the lymphatic and venous systems of the anterior abdominal wall is arranged around a horizontal plane above which drainage is in a cranial direction and below which drainage is in a caudal direction. Which horizontal plane is being referred to?
Your Answer: Level of the umbilicus
Explanation:The umbilicus is a key landmark for the lymphatic and venous drainage of the abdominal wall. Above it, lymphatics drain into the axillary lymph nodes and the venous blood drains into the superior epigastric vein, into the internal thoracic vein. Below it, lymphatics drain into the superficial inguinal lymph nodes while venous blood drains into the inferior epigastric vein and the external iliac vein.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 24
Correct
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In relation to the muscles of facial expression, It is true to say:
Your Answer: They are in the same subcutaneous plane as the platysma muscle
Explanation:The facial muscles generally originate from the facial bones and attach to the skin, in the same plane as the platysma muscle. They are all innervated by cranial nerve VII (the facial nerve). The occipitofrontalis muscle consists of two parts: The occipital belly, near the occipital bone, and the frontal belly, near the frontal bone.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 25
Incorrect
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A patient who has used NSAIDS for many years presents to the A&E with symptoms of acute haemorrhagic shock. An emergency endoscopy is done that shows that a duodenal ulcer has perforated the posterior wall of the first part of the duodenum. Which artery is most likely to be the cause of the haemorrhage?
Your Answer: Superior mesenteric
Correct Answer: Gastroduodenal
Explanation:The gastroduodenal artery is a branch of the hepatic artery and descends near the pylorus between the first part of the duodenum and the neck of the pancreas to divide at the lower border of the duodenum into the right gastroepiploic and pancreaticoduodenal arteries. Before it divides, it gives off a few branches to the pyloric end of the stomach and to the pancreas. The artery that is most likely involved in this situation is the gastroduodenal artery since it is posterior to the first part of the duodenum.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 26
Incorrect
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A ‘claw hand’ is usually associated with injury to which of the following nerves?
Your Answer: Median nerve
Correct Answer: Ulnar nerve
Explanation:A ‘claw hand’ is associated with injury to the ulnar nerve at the wrist affecting the interossei, lumbricals and hypothenar muscles of the hand. It is characterized by hypothenar eminence wasting, hyperextended metacarpophalangeal joints and flexed interphalangeal joints.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 27
Incorrect
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During laparoscopic surgery to repair a direct inguinal hernia in a 68-year old man, the surgeon asked the registrar to look at the medial inguinal fossa to identify the direct inguinal hernia. To do so, she would have to look at the area that is between the:
Your Answer:
Correct Answer: Medial umbilical ligament and inferior epigastric artery
Explanation:The medial umbilical fold is made by the medial umbilical ligament-which is the obliterated portion of the umbilical artery, while the lateral umbilical fold is a fold of peritoneum over the inferior epigastric vessels. The median umbilical fold is a midline structure made by the median umbilical ligament i.e. the obliterated urachus. The medial inguinal fossa is the space on the inner abdominal wall between the medial umbilical fold and the lateral umbilical fold. It is place in the abdominal wall where there is an area of weak fascia i.e. the inguinal triangle through which direct inguinal hernias break through. The lateral inguinal fossa on the other hand is a space lateral to the lateral umbilical fold. Indirect inguinal hernias push through this space.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 28
Incorrect
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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:
Correct 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 29
Incorrect
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A 38-year old woman presents to the clinic with a 2 cm eczema-like lesion on the areolar region of her left breast, for 5 months. Biopsy of the lesion showed large cells at the dermal-epidermal junction with positive staining for mucin. What is the likely diagnosis?
Your Answer:
Correct Answer: Paget’s disease of the breast
Explanation:Paget’s disease of the breast or nipple resembles eczema in appearance with an underlying carcinoma typically. The disease is usually unilateral and presents with inflammation, oozing and crusting along with a non-healing ulcer. Treatment is often delayed due to the innocuous appearance but can be fatal. It results due to spread of neoplastic cells from the ducts of the mammary gland to the epithelium.
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This question is part of the following fields:
- Pathology
- Women's Health
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Question 30
Incorrect
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Which lymph nodes are most likely to enlarge due to the spread of infection through the lymphatic channels in a patient with a boil on his scrotum?
Your Answer:
Correct Answer: Superficial inguinal nodes
Explanation:The superficial inguinal nodes drain the perineum and the external genitalia which include the scrotum and the labia majora. The testes, however, drain to the lumbar nodes.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 31
Incorrect
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A neurotransmitter of the nigrostriatal pathway is:
Your Answer:
Correct Answer: Dopamine
Explanation:Dopamine acts as a neurotransmitter in the brain, activating dopamine receptors. It is also a neurohormone released from the hypothalamus. It plays an important role in the reward system. It is believed that dopamine provides a teaching signal to parts of the brain responsible for acquiring new motor sequences (behaviours), by activation of dopamine neurons when an unexpected reward is presented. Loss of dopamine neurones in the nigrostriatal pathway causes Parkinson’s disease. In the frontal lobes, dopamine controls the flow of information from other areas of the brain, and thus, dopamine disorders in this region can cause a decline in neurocognitive functions, especially memory, attention and problem solving. Reduced dopamine concentrations in the prefrontal cortex are thought to contribute to attention-deficit disorder and some symptoms of schizophrenia. Dopamine is also the primary neuroendocrine regulator of the secretion of prolactin from the anterior pituitary gland. Dopamine is also commonly associated with the pleasure system of the brain. This plays a key role in understanding the mechanism of action of drugs (such as cocaine and the amphetamines), which seem to be directly or indirectly related to the increase of dopamine.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 32
Incorrect
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Atrial septal defect (ASD) is most likely to be due to incomplete closure of which one of the following structures:
Your Answer:
Correct Answer: Foramen ovale
Explanation:Atrial septal defect is a congenital heart defect that results in a communication between the right and left atria of the heart and may involve the interatrial septum. It results from incomplete closure of the foramen ovale which is normally open during fetal life and closes just after birth.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 33
Incorrect
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What is the role of factor VII in coagulation?
Your Answer:
Correct 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 34
Incorrect
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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:
Correct 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 35
Incorrect
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The thoracic duct :
Your Answer:
Correct Answer: varies in length from 38 to 45 cm
Explanation:The thoracic duct is the main drainage of lymph in the body. It varies in length from 38 to 45 cm and extends from the second lumbar vertebra to the root of the neck.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 36
Incorrect
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The following joint has an anastomotic circulation that is provided by branches of the brachial artery:
Your Answer:
Correct Answer: Elbow joint
Explanation:The arterial anastomoses of the elbow joint is contributed by branches of the brachial artery and the Profunda brachii artery. The brachial artery gives off the superior ulnar collateral artery and the inferior collateral artery. On the other hand, the Profunda brachii gives off the radial and medial recurrent arteries.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 37
Incorrect
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Regarding the coagulation cascade, Factor VII:
Your Answer:
Correct Answer: Is a serine protease
Explanation:Factor VII (FVII) is a zymogen for a vitamin K-dependent serine protease essential for the initiation of blood coagulation. It is synthesized primarily in the liver and circulates in plasma. Within the liver, hepatocytes are involved in the synthesis of most blood coagulation factors, such as fibrinogen, prothrombin, factor V, VII, IX, X, XI, XII, as well as protein C and S, and antithrombin, whereas liver sinusoidal endothelial cells produce factor VIII and von Willebrand factor.
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This question is part of the following fields:
- General
- Physiology
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Question 38
Incorrect
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After a total colectomy and ileotomy, a 50-year old diabetic man who was a known case of diabetic nephropathy had persistent metabolic acidosis. The patient appeared well perfused, with normal vital signs and normal fluid balance. Investigations revealed:
Sodium = 132 mmol/l
Potassium = 6.6 mmol/l
Creatinine = 185 μmol/l (2.16 mg/dl)
Chloride = 109 μmol/l
8am cortisol = 500 nmol/l (18 μg/dl)
pH = 7.29, p(CO2) = 27 mmHg
p(O2) = 107 mmHg
standard bicarbonate = 12 mmol/l.
What is the likely causes of his acidosis?Your Answer:
Correct Answer: Renal tubular acidosis
Explanation:Acidosis here is due to low bicarbonate. The low p(CO2) is seen in compensation. The anion gap is normal, ruling out intra-abdominal ischaemia (which leads to metabolic acidosis). If it was a gastrointestinal aetiology, low potassium would be seen. The history of diabetic nephropathy predisposes to renal tubular acidosis. Type 4 (hyporeninaemic hypoaldosteronism) is associated with high potassium and is found in diabetic and hypertensive renal disease.
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This question is part of the following fields:
- Physiology
- Respiratory
-
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Question 39
Incorrect
-
Which of the following is not seen as a complication of wound healing?
Your Answer:
Correct Answer: Malignancy
Explanation:Complications in wound healing can originate due to abnormalities in the repair process. These abnormalities are :
1) Deficient scar formation: insufficient granulation tissue can lead to wound dehiscence and ulceration. Dehiscence or wound rupture is seen most commonly in abdominal surgery due to increased intraabdominal pressure. Ulcerations are common in extremity wounds due to inadequate vascularization.
2) Excessive formation of repair components: collagen being laid down may begin normally however later lead to a raised scar also called a hypertrophic scar, which can extend beyond its boundaries to form a keloid and
3) Formation of contractures.
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This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
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Question 40
Incorrect
-
A patient presents with loss of fine touch and sense of proprioception in the lower part of the body (below T6). He is likely to have a lesion involving:
Your Answer:
Correct Answer: Gracile nucleus
Explanation:The gracile nucleus is located in the medulla oblongata and is one of the dorsal column nuclei involved in the sensation of fine touch and proprioception. It contains second-order neurons of the dorsal column–medial lemniscus system, that receive inputs from sensory neurones of the dorsal root ganglia and send axons that synapse in the thalamus.
The gracile nucleus and fasciculus carry epicritic, kinaesthetic and conscious proprioceptive information from the lower part of the body (below the level of T6 in the spinal cord). Similar information from the upper part of body (above T6, except for face and ear) is carried by the cuneate nucleus and fasciculus. The information from face and ear is carried by the primary sensory trigeminal nucleus.
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This question is part of the following fields:
- Neurology
- Physiology
-
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Question 41
Incorrect
-
The petrous part of the internal carotid artery is located inside of which cranial bone?
Your Answer:
Correct Answer: Temporal
Explanation:The petrous segment, or C2, of the internal carotid is that which is inside the petrous part of the temporal bone. This segment extends until the foramen lacerum. The petrous portion classically has three sections: an ascending, or vertical portion; the genu, or bend; and the horizontal portion.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 42
Incorrect
-
The periphery of a haematoma is infiltrated by fibroblasts, collagen and new vasculature. This process is best described as?
Your Answer:
Correct Answer: Organisation of the haematoma
Explanation:Formation of granulation tissue at the periphery of the hematoma is a normal process leading to resolution. This granulation tissue is composed of new capillaries, fibroblasts and collagen. Lysis of a blood clot can occur, but the actual process of this response is known as organization, wherein the scar tissue will become part of the vessels. This is followed by recanalization and embolization which can lead to eventual complications. Proliferation of a clot will occur due to an imbalance in the clotting and lysing systems. Thrombosis has nothing to do with the process described above.
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This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
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Question 43
Incorrect
-
A urologist makes a transverse suprapubic incision to retrieve a stone from the urinary bladder. Which of the following abdominal wall layers will the surgeon NOT traverse?
Your Answer:
Correct Answer: Posterior rectus sheath
Explanation:Pfannenstiel incision (a transverse suprapubic incision) is made below the arcuate line. Thus, there is no posterior layer of the rectus sheath here, only the transversalis fascia lines the inner layer of the rectus abdominis. The layers traversed include: skin, superficial fascia (fatty and membranous), deep fascia, anterior rectus sheath, rectus abdominis muscle, transversalis fascia, extraperitoneal connective tissue and peritoneum.
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This question is part of the following fields:
- Abdomen
- Anatomy
-
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Question 44
Incorrect
-
A 49-year-old woman with acute renal failure has a total plasma [Ca2+] = 2. 5 mmol/l and a glomerular filtration rate of 160 l/day. What is the estimated daily filtered load of calcium?
Your Answer:
Correct Answer: 240 mmol/day
Explanation:Calcium is the most abundant mineral in the human body. The average adult body contains in total approximately 1 kg of calcium of which 99% is in the skeleton in the form of calcium phosphate salts. The extracellular fluid (ECF) contains approximately 22 mmol, of which about 9 mmol is in the plasma. About 40% of total plasma Ca2+ is bound to proteins and not filtered at the glomerular basement membrane. Therefore, the estimated daily filtered load is 1.5 mmol/l × 160 l/day = 240 mmol/day. The exact amount of free versus total Ca2+ depends on the blood pH: free Ca2+ increases during acidosis and decreases during alkalosis.
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This question is part of the following fields:
- Physiology
- Renal
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Question 45
Incorrect
-
Which of the following mediators of inflammation requires arachidonic acid for synthesis?
Your Answer:
Correct Answer: Prostaglandins
Explanation:Arachidonic acid is normally present in the phospholipids that make up the cell membrane and is cleaved by phospholipase A2 from the phospholipid. Arachidonic acid is a precursor for the production of eicosanoids which include: 1) prostaglandins, prostacyclins and thromboxane, 2) leukotrienes and 3) anandamides. The production of these products along with their action on the body is called the arachidonic acid cascade.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 46
Incorrect
-
A young female in the 15th week of pregnancy presented to the emergency department with the passage of grape-like masses per vagina. Dilatation and curettage was done and microscopy revealed large avascular villi with trophoblastic proliferation. Which one of the following investigations is best recommended for her follow-up?
Your Answer:
Correct Answer: Serum β-hCG
Explanation:Trophoblast is the layer of cells surrounding the blastocyst and that later develops into the chorion and amnion. Gestational trophoblastic disease is a tumour arising from this trophoblast. It can occur during or after either an intrauterine or ectopic pregnancy. If it occurs in a pregnant woman, it usually leads to spontaneous abortion, eclampsia or fetal death. It can be either malignant or benign.
In suspected cases, investigations include measurement of serum beta subunit of human chorionic gonadotrophin (β-hCG) and pelvic ultrasound. Confirmatory test is a biopsy. Post-removal, the disease is classified clinically to assess further treatment. To assess the presence of metastases, further work-up includes computed tomography of the brain, chest, abdomen and pelvis. Chemotherapy is usually needed for persistent disease. If at least three consecutive, weekly serum β-hCG measurements are normal, treatment is considered successful. Follow-up is also done by measuring β-hCG.
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This question is part of the following fields:
- Pathology
- Women's Health
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Question 47
Incorrect
-
A 17-year-old female was given an antibiotic for a urinary tract infection. After taking the medication the patient developed Steven-Johnson syndrome. Which particular antibiotic usually causes Steven-Johnson syndrome?
Your Answer:
Correct Answer: Sulphonamides
Explanation:Stevens–Johnson syndrome (SJS) is a type of severe skin reaction. The most common cause is certain medications such as lamotrigine, carbamazepine, allopurinol, sulphonamide antibiotics, and nevirapine.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 48
Incorrect
-
Mallory bodies are characteristic of which of the following conditions?
Your Answer:
Correct Answer: Alcoholic hepatitis
Explanation:Mallory bodies (or ‘alcoholic hyaline’) are inclusion bodies in the cytoplasm of liver cells, seen in patients of alcoholic hepatitis; and also in Wilson’s disease. These pathological bodies are made of intermediate keratin filament proteins that are ubiquinated or bound by proteins like heat chock protein. Being highly eosinophilic, they appear pink on haematoxylin and eosin staining.
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This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
-
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Question 49
Incorrect
-
A 26-year-old female patient had the following blood report: RBC count = 4. 0 × 106/μl, haematocrit = 27% and haemoglobin = 11 g/dl, mean corpuscular volume (MCV) = 90 fl, mean corpuscular haemoglobin concentration (MCHC) = 41 g/dl. Further examination of blood sample revealed increased osmotic fragility of the erythrocytes. Which of the following is the most likely cause of this patient’s findings?
Your Answer:
Correct Answer: Spherocytosis
Explanation:Spherocytes are small rounded RBCs. It is due to an inherited defect of the RBC cytoskeleton membrane tethering proteins. Membrane blebs form that are lost over time and cells become round instead of biconcave. As it is a normochromic anaemia, the MCV is normal. it is diagnosed by osmotic fragility test which reveals increased fragility in a hypotonic solution.
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This question is part of the following fields:
- General
- Physiology
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Question 50
Incorrect
-
A 66-year-old man complains of constant headaches. On physical examination, the only relevant sign is a dark brown mole located on left his arm which has grown in size over the years and is itchy and painful. A MRI of the brain revealed a solitary lesion at the grey-white junction in the right frontal lobe, without ring enhancement. This lesion is most likely to be:
Your Answer:
Correct Answer: Metastatic carcinoma
Explanation:The location of the mass at the grey–white junction is typical of a metastasis. The most frequent types of metastatic brain tumours originate in the lung, skin, kidney, breast and colon. These tumour cells reach the brain via the bloodstream. This patient is likely to have skin cancer, which caused the metastatic brain tumour.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 51
Incorrect
-
Where is the mental foramen located?
Your Answer:
Correct Answer: In the mandible
Explanation:The mental foramen is found bilaterally on the anterior surface of the mandible adjacent to the second premolar tooth. The mental nerve and terminal branches of the inferior alveolar nerve and mental artery leave the mandibular canal through it.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 52
Incorrect
-
A 63-year-old woman complains of a new, persisting headache. She is diagnosed with vasculitis and the histopathological sample revealed giant-cell arteritis. What is the most probable diagnose?
Your Answer:
Correct Answer: Temporal arteritis
Explanation:Giant cell arteritis (GCA), also known as temporal arteritis, is the most common systemic inflammatory vasculitis that occurs in adults. It is of unknown aetiology and affects arteries large to small however the involvement of the superficial temporal arteries is almost always present. Other commonly affected arteries include the ophthalmic, occipital and vertebral arteries, therefore GCA can result in systemic, neurologic, and ophthalmologic complications. GCA usually is found in patients older than 50 years of age and should always be considered in the differential diagnosis of a new-onset headache accompanied by an elevated erythrocyte sedimentation rate. Diagnosis depends on the results of artery biopsy.
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This question is part of the following fields:
- Cardiovascular
- Pathology
-
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Question 53
Incorrect
-
Cranial nerve XII, the hypoglossal nerve, innervates which one of the following muscles in the list?
Your Answer:
Correct Answer: Hyoglossus
Explanation:The cranial nerve XII, hypoglossal nerve, innervates all the intrinsic and extrinsic muscles of the tongue except the palatoglossus. The muscles of the tongue innervated by this nerve include the extrinsic muscles; hyoglossus, styloglossus, genioglossus and the intrinsic muscles; superior longitudinal, inferior longitudinal, vertical and transverse muscles. The salpingopharyngeus, palatoglossus and the palatopharyngeus muscles are innervated by the vagus nerve. The stylopharyngeus muscle is innervated by the glossopharyngeal nerve (CN IX). The mylohyoid muscle is innervated by the inferior alveolar nerve, a branch of the mandibular nerve. Finally, the geniohyoid muscle is innervated by the olfactory nerve (CN I) via the hypoglossal nerve.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 54
Incorrect
-
The inferior palpebral nerve ascends behind the orbicularis oculi. What is the terminal branch of the inferior palpebral nerve?
Your Answer:
Correct Answer: Infraorbital nerve
Explanation:The inferior palpebral nerve is a branch of the maxillary nerve. It supplies the skin and conjunctiva of the lower eyelid.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 55
Incorrect
-
A 45 year old man who complains of chronic post prandial, burning epigastric pain undergoes a gastrointestinal endoscopy. There is no apparent mass or haemorrhage and a biopsy is taken from the lower oesophageal mucosa just above the gastro-oesophageal junction. The results reveal the presence of columnar cells interspersed with goblet cells. Which change best explains the above mentioned histology?
Your Answer:
Correct Answer: Metaplasia
Explanation:Metaplasia is the transformation of one type of epithelium into another as a means to better cope with external stress on that epithelium. In this case metaplasia occurs due to the inflammation resulting from gastro-oesophageal reflux disease. Dysplasia is disordered cellular growth. Hyperplasia is an increase in cell number but not cell type i.e. transformation. Carcinoma is characterized by cellular atypia. Ischaemia would result in necrosis with ulceration. Carcinoma insitu involves dysplastic atypical cells with the basement membrane intact and atrophy would mean a decrease in number of cells.
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This question is part of the following fields:
- Cell Injury & Wound Healing; Gastrointestinal
- Pathology
-
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Question 56
Incorrect
-
Leakage from a silicone breast implant can lead to:
Your Answer:
Correct Answer: Pain and contracture
Explanation:Breast implants are mainly: saline-filled and silicone gel-filled. Complications include haematoma, fluid collections, infection at the surgical site, pain, wrinkling, asymmetric appearance, wound dehiscence and thinning of the breast tissue.
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This question is part of the following fields:
- Pathology
- Women's Health
-
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Question 57
Incorrect
-
The mandibular nerve, which is the largest of the 3 divisions of the trigeminal nerve, exits the cranial cavity through which foramen?
Your Answer:
Correct Answer: Foramen ovale
Explanation:At the base of the skull the foramen ovale is one of the larger of the several holes that transmit nerves through the skull. The following structures pass through foramen ovale: mandibular nerve, motor root of the trigeminal nerve, accessory meningeal artery, lesser petrosal nerve, a branch of the glossopharyngeal nerve, emissary vein connecting the cavernous sinus with the pterygoid plexus of veins and occasionally the anterior trunk of the middle meningeal vein.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 58
Incorrect
-
Which of the following has the least malignant potential?
Your Answer:
Correct Answer: Hyperplastic polyp
Explanation:Non-neoplastic (non-adenomatous) colonic polyps include hyperplastic polyps, hamartomas, juvenile polyps, pseudopolyps, lipomas, leiomyomas and others.
An autosomal dominant condition, Peutz–Jeghers syndrome is a disease that is characterized by multiple hamartomatous polyps in the stomach, small bowel and colon. Symptoms of this syndrome include hyperpigmentation of the skin and mucous membranes, especially of the lips and gums.
Juvenile polyps develop in children, and once they outgrow their blood supply, they autoamputate around puberty. In cases of uncontrolled bleeding or intussusception, treatment is needed.
Inflammatory polyps and pseudopolyps occur in chronic ulcerative colitis and Crohn’s disease. There is an increased risk of cancer with multiple juvenile polyps (not with sporadic polyps).
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This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
-
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Question 59
Incorrect
-
The wound healing process is documented in patients undergoing laparoscopic procedures. The port incisions are sutured closed and the wounds observed every few weeks for re-epithelialisation and tensile strength. Which substance is mostly likely to be found at a cellular level involved in wound healing?
Your Answer:
Correct Answer: Tyrosine kinase
Explanation:Cell surface growth factor receptors require intercellular proteins such as tyrosine kinase which are necessary to initiate a series of events that eventually lead to cell division and growth. Tyrosine kinase is an enzyme that transfers a phosphate group to the tyrosine residue in a protein. This phosphorylation will lead to an up regulation of the enzyme activity.
Fibronectin acts in the extracellular matrix to bind macromolecules (such as proteoglycans) via integrin receptors to aid attachment and migration of cells.
Laminin is an extracellular matrix component that is abundant in basement membranes.
Hyaluronic acid is one of the proteoglycans in the extracellular matrix.
Collagen fibres are part of the extracellular matrix that gives strength and stability to connective tissues.
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This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
-
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Question 60
Incorrect
-
During cardiac catheterisation in a 20-year old man, the following data is obtained: Pressure (mmHg), O2 saturation (%) Right atrium 7 (N = 5) 90 (N = 75), Right ventricle 35/7 (N = 25/5) 90 (N = 75), Pulmonary artery 35/8 (N = 25/15), 90 (N = 75), Left atrium 7 (N = 9) 95 (N = 95), Left ventricle 110/7 (N = 110/9) 95 (N = 95), Aorta 110/75 (N = 110/75) 95 (N = 95) where N = Normal value. What is the likely diagnosis?
Your Answer:
Correct Answer: Atrial septal defect
Explanation:A congenital heart disease, ASD or atrial septal defect leads to a communication between the right and left atria due to a defect in the interatrial septum. This leads to mixing of arterial and venous blood from the right and left side of the heart. The hemodynamic significance of this defect depends on the presence of shunting of blood. Normally, the left side of the heart has higher pressure than the right as the left side has to pump blood throughout the body. A large ASD (> 9 mm) will result in a clinically significant left-to-right shunt, causing volume overload of the right atrium and ventricle, eventually leading to heart failure. Cardiac catheterization would reveal very high oxygen saturation in the right atrium, right ventricle and pulmonary artery. Eventually, the left-to-right shunt will lead to pulmonary hypertension and increased afterload in the right ventricle, along with the increased preload due to the shunted blood. This will either cause right ventricular failure, or raise the pressure in the right side of the heart to equal or more than that in the left. Elevation of right atrial pressure to that of left atrial pressure would thus lead to diminishing or complete cessation of the shunt. If left uncorrected, there will be reversal of the shunt, known as Eisenmenger syndrome, resulting in clinical signs of cyanosis as the oxygen-poor blood form right side of the heart will mix with the blood in left side and reach the peripheral vascular system.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 61
Incorrect
-
A surgeon performing a Whipple's procedure, that involves mobilizing the head of the pancreases, accidentally injured a structure immediately posterior to the neck of the pancrease which bled out. Which structure is most likely to have been injured?
Your Answer:
Correct Answer: Superior mesenteric artery
Explanation:The structure immediately posterior to the neck of the pancreas is the superior mesenteric vein. The neck of the pancreas lies anterior to the superior mesenteric vein, which joins with the splenic vein to form the portal vein.
The superior mesenteric artery (SMA) is also located in proximity to the neck of the pancreas. Specifically, the SMA emerges from the abdominal aorta just below the level of the pancreas and passes posterior to the neck of the pancreas before it descends into the mesentery to supply the intestines. Thus, both the superior mesenteric vein and the superior mesenteric artery are key vascular structures related to the posterior aspect of the neck of the pancreas.
Bleeding out would suggest an arterial injury.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 62
Incorrect
-
Which of the following foramina will the ophthalmic artery pass through in order to reach the eye?
Your Answer:
Correct Answer: Optic canal
Explanation:The optic foramen is the opening to the optic canal. The canal is located in the sphenoid bone; it is bounded medially by the body of the sphenoid and laterally by the lesser wing of the sphenoid. The superior surface of the sphenoid bone is bounded behind by a ridge, which forms the anterior border of a narrow, transverse groove, the chiasmatic groove (optic groove). The groove ends on either side in the optic foramen, which transmits the optic nerve and ophthalmic artery into the orbital cavity. Compared to the optic nerve, the ophthalmic artery is located inferolaterally within the canal.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 63
Incorrect
-
A 45 year-old male, with behavioural changes developed euvolemic hyponatraemia. Which of the following conditions most likely predisposed the patient to develop euvolemic hyponatraemia?
Your Answer:
Correct Answer: Psychosis
Explanation:In euvolemic hyponatraemia, there is volume expansion in the body, there is no oedema, but hyponatremia occurs. Causes include: state of severe pain or nausea, psychosis, brain trauma, SIADH, hypothyroidism and glucocorticoid deficiency.
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This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
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Question 64
Incorrect
-
Choose the most correct answer regarding the obturator internus muscle.
Your Answer:
Correct Answer: It emerges from the pelvis through the lesser sciatic foramen
Explanation:The obturator internus arises from the inner surface of the anterolateral wall of the pelvis and the pelvic surface of the obturator membrane. The fibres converge rapidly towards the lesser sciatic foramen and end in four or five tendinous bands and leave the pelvis through the lesser sciatic foramen.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 65
Incorrect
-
A 25-year-old woman complains of generalised swelling and particularly puffiness around the eyes which is worst in the morning. Laboratory studies showed:
Blood urea nitrogen (BUN) = 30 mg/dl
Creatinine = 2. 8 mg/dl
Albumin = 2. 0 mg/dl
Alanine transaminase (ALT) = 25 U/l
Bilirubin = 1 mg/dl
Urine analysis shows 3+ albumin and no cells.
Which of the following is the most likely diagnosis?Your Answer:
Correct Answer: Nephrotic syndrome
Explanation:Nephrotic syndrome is a disorder in which the glomeruli have been damaged, characterized by:
– Proteinuria (>3.5 g per 1.73 m2 body surface area per day, or > 40 mg per square meter body surface area per hour in children)
– Hypoalbuminemia (< 2,5 g/dl) – Hyperlipidaemia, and oedema (generalized anasarca).
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This question is part of the following fields:
- Physiology
- Renal
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Question 66
Incorrect
-
A chest X-ray in a healthy, non-smoker, asymptomatic 48-year-old woman reveals a 2cm left lower lobe well-defined round opacity. Which of the following conditions is most probably responsible for this finding?
Your Answer:
Correct Answer: Pulmonary hamartoma
Explanation:An asymptomatic healthy patient with no history of smoking and a lesion of small size most probably has a benign lung lesion. Hamartomas are one of the most common benign tumours of the lung that accounts for approximately 6% of all solitary pulmonary nodules. Pulmonary hamartomas are usually asymptomatic and therefore are found incidentally when performing an imaging test for other reasons.
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This question is part of the following fields:
- Pathology
- Respiratory
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Question 67
Incorrect
-
Dicloxacillin is an antibiotic; the subclass that dicloxacillin belongs to is:
Your Answer:
Correct Answer: Penicillin
Explanation:Dicloxacillin is a narrow-spectrum beta-lactam antibiotic. It is used to treat infections caused by susceptible Gram-positive bacteria and most effective against beta-lactamase-producing organisms such as Staphylococcus aureus. To decrease the development of resistance, dicloxacillin is recommended to treat infections that are suspected or proven to be caused by beta-lactamase-producing bacteria.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 68
Incorrect
-
Pseudomonas aeruginosa is a multidrug resistant pathogen that causes hospital-acquired infections. It is usually treated with piperacillin or another antibiotic. Which of the following is the other antibiotic?
Your Answer:
Correct Answer: Azlocillin
Explanation:Azlocillin, like piperacillin, is an acylampicillin antibiotic with an extended spectrum of activity and greater in vitro potency than the carboxypenicillins. Azlocillin is similar to mezlocillin and piperacillin. It demonstrates antibacterial activity against a broad spectrum of bacteria, including Pseudomonas aeruginosa.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 69
Incorrect
-
The chest X-ray of an 10-year-old boy, that presented with low-grade fever and cough, revealed hilar enlargement and parenchymal consolidation in the middle lobes. These X-ray findings are more typical for which of the following diagnoses?
Your Answer:
Correct Answer: Pulmonary tuberculosis
Explanation:Primary pulmonary tuberculosis is seen in patients exposed to Mycobacterium tuberculosis for the firs time. The main radiographic findings in primary pulmonary tuberculosis include homogeneous parenchymal consolidation typically in the lower and middle lobes, lymphadenopathy, miliary opacities and pleural effusion.
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This question is part of the following fields:
- Pathology
- Respiratory
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Question 70
Incorrect
-
Which of the following will be a seen in a patient with a plasma thyroid-stimulating hormone (TSH) level of 14 mU/l (normal < 5 mU/l) and a low T3 resin uptake of 19% (normal 25–35%)?
Your Answer:
Correct Answer: Periorbital swelling and lethargy
Explanation:Low T3 resin uptake combined with raised TSH is indicative of hypothyroidism. Signs and symptoms include dull expression, facial puffiness, lethargy, periorbital swelling due to infiltration with mucopolysaccharides, bradycardia and cold intolerance. Anxiety, palpitations, tachycardia, raised body temperature, heat intolerance and weight loss are all seen in hyperthyroidism.
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This question is part of the following fields:
- Endocrinology
- Physiology
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Question 71
Incorrect
-
Which of the following associations is correctly matched with the body's defence mechanism in fighting infection?
Your Answer:
Correct Answer: Specific cellular mechanism → cytotoxic T cells
Explanation:The immune system has certain levels of defence against pathogens. First line includes simple barriers such as skin, mucosa and stomach acid that prevent the pathogen from entering into the body. If this barrier is breached then the innate immune system is activated which includes leukocytes (macrophages, neutrophils, mast cells, eosinophils, basophils, natural killer cells). If the pathogens invade the second layer of defence then the third layer, adaptive immunity is activated, which includes B and T lymphocytes. B cells provide a humoral response whereas cytotoxic T cells have specific cellular mechanisms. They maintain a memory of past infections and are activated faster following a recurrence.
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This question is part of the following fields:
- General
- Physiology
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Question 72
Incorrect
-
The transmembrane proteins responsible for resting membrane potential of vascular smooth muscle cells was blocked by a drug. Which of the following transmembrane proteins were blocked by this drug?
Your Answer:
Correct Answer: K+ channels
Explanation:The resting membrane potential is due to selective permeability of the membrane to potassium ions. The Na/K pump is responsible for the generation of a gradient across the membrane and it is due to the inherent ability of the K channels to allow diffusion back into the nerve at rest which charges the cells. In reality, the resting membrane potential is more positive because of small contributions by Na+ channels, Cl− channels and non-selective cation channels.
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This question is part of the following fields:
- General
- Physiology
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Question 73
Incorrect
-
Which of the following is a landmark to identify the site of the 2nd costal cartilage?
Your Answer:
Correct Answer: Sternal angle
Explanation:The sternal angle is an important part where the second costal cartilage attaches to the sternum. Finding the sternal angle will help in finding the second costal cartilage and intercostal space.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 74
Incorrect
-
Which of the following is likely to result in hematocolpos in a 12-year old girl?
Your Answer:
Correct Answer: Imperforate hymen
Explanation:Hematocolpos means accumulation of blood in vagina and hematometra is accumulation of blood in the uterus. These are most likely seen with an imperforate hymen; which is seen I 1 in 2000 females. If spontaneous resolution does not occur, treatment involves making a hole in the hymen to allow discharge of menstrual blood.
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This question is part of the following fields:
- Pathology
- Women's Health
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Question 75
Incorrect
-
Which of the following clinical signs will be demonstrated in a case of Brown-Séquard syndrome due to hemisection of the spinal cord at mid-thoracic level?
Your Answer:
Correct Answer: Ipsilateral spastic paralysis, ipsilateral loss of vibration and proprioception (position sense) and contralateral loss of pain and temperature sensation beginning one or two segments below the lesion
Explanation:Brown–Séquard syndrome results due to lateral hemisection of the spinal cord and results in a loss of motricity (paralysis and ataxia) and sensation. The hemisection of the cord results in a lesion of each of the three main neural systems: the principal upper motor neurone pathway of the corticospinal tract, one or both dorsal columns and the spinothalamic tract. As a result of the injury to these three main brain pathways the patient will present with three lesions. The corticospinal lesion produces spastic paralysis on the same side of the body (the loss of moderation by the upper motor neurons). The lesion to fasciculus gracilis or fasciculus cuneatus results in ipsilateral loss of vibration and proprioception (position sense). The loss of the spinothalamic tract leads to pain and temperature sensation being lost from the contralateral side beginning one or two segments below the lesion. At the lesion site, all sensory modalities are lost on the same side, and an ipsilateral flaccid paralysis.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 76
Incorrect
-
A 24-year old patient diagnosed with a direct inguinal hernia was scheduled for surgery to have the hernia repaired. The hernia was discovered to be protruding through the Hesselbach's triangle (inguinal triangle). Which of the following blood vessels that is a branch of the external iliac artery forms the lateral border of this triangle?
Your Answer:
Correct Answer: Inferior epigastric
Explanation:The inguinal triangle is formed by the following structures; inguinal ligament at the base; inferior epigastric vessels laterally and the lateral border of the rectus sheath medially. This triangle (also known as Hesselebach’s triangle) is where direct inguinal hernias protrude. The inferior epigastric artery is this the branch of the external iliac artery being referred to. All the other blood vessels are branches of the internal iliac artery.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 77
Incorrect
-
A 60-year-old man complains of pain in his left thigh. An X-ray reveals bowing of the affected femur, increased bone density, bony enlargement, abnormal bone architecture with coarse cortical trabeculations, and stress microfractures. Which is the most likely diagnosis in this case?
Your Answer:
Correct Answer: Paget’s disease of bone
Explanation:Paget’s disease of bone is a chronic disorder of the adult skeleton in which bone turnover is accelerated in localised areas, replacing normal matrix with softened and enlarged bone and causing gradual pain and deformity in some cases. It is more predominant in men over the age of 40. Characteristic X-ray findings include increased bone density, abnormal architecture with coarse cortical trabeculation or cortical thickening, bowing and bony enlargement; there might also be stress microfractures of the tibia or femur.
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This question is part of the following fields:
- Orthopaedics
- Pathology
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Question 78
Incorrect
-
A growing tumour is impinging on the lingual artery in the floor of the mouth. Which structure will experience decreased blood flow?
Your Answer:
Correct Answer: The sublingual gland
Explanation:The paired sublingual glands are major salivary glands in the mouth. They are the smallest, most diffuse, and the only unencapsulated major salivary glands. They provide only 3-5% of the total salivary volume. The gland receives its blood supply from the sublingual and submental arteries. The sublingual artery is a branch of the lingual artery, thus damage to the lingual artery will decrease the blood flow to the sublingual gland.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 79
Incorrect
-
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:
Correct 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 80
Incorrect
-
A sudden loud sound is more likely to result in cochlear damage than a slowly developing loud sound. This is because:
Your Answer:
Correct Answer: There is a latent period before the attenuation reflex can occur
Explanation:On transmission of a loud sound into the central nervous system, an attenuation reflex occurs after a latent period of 40-80 ms. This reflex contracts the two muscles that pull malleus and stapes closer, developing a high degree of rigidity in the entire ossicular chain. This reduces the ossicular conduction of low frequency sounds to the cochlea by 30-40 decibels. In this way, the cochlea is protected from damage due to loud sounds (these are low frequency sounds) when they develop slowly.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 81
Incorrect
-
If your EEG shows waves with a frequency range of 8-12 Hz, the waves most likely to be seen are:
Your Answer:
Correct 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 82
Incorrect
-
A 50 year old woman presented with excessive bleeding after an inguinal hernia repair. Labs are suggestive of a primary haemostasis defect. Deficiency of which of the following is most likely to cause it?
Your Answer:
Correct Answer: Platelets
Explanation:Primary haemostatic control means the first line of defence against immediate bleeding. This is carried out by the platelets. They immediately form a haemostatic plug at the site of injury. Coagulation starts within 20s after an injury to the blood vessel which damage the endothelial cells. Secondary haemostasis follows which includes activation of the coagulation factors to form fibrin strands which mesh together forming the platelet plug. Platelets interact with platelet collagen receptor, glycoprotein Ia/IIa and to collagen fibres in the vascular endothelium. This adhesion is mediated by von Willebrand factor (vWF), which forms links between the platelet glycoprotein Ib/IX/V and collagen fibrils. The platelets are then activated and release the contents of their granules into the plasma, in turn activating other platelets and white blood cells.
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This question is part of the following fields:
- General
- Physiology
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Question 83
Incorrect
-
If a 55-year old gentleman who has suffered a stroke, develops a tremor in his fingers that worsens on reaching for an object, what part of his brain is likely to be involved?
Your Answer:
Correct Answer: Cerebellum
Explanation:The cerebellum plays an important role in the integration of sensory perception and motor output. Multiple neural pathways link the cerebellum with the motor cortex and the spinocerebellar tract. The cerebellum uses the constant feedback on body position to fine-tune the movements and integrates these pathways. The patient described here has a characteristic cerebellar tremor that is a slow, broad tremor of the extremities and occurs at the end of a purposeful movement.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 84
Incorrect
-
Which of the following structure forms the floor of the posterior triangle of the neck:
Your Answer:
Correct Answer: Prevertebral fascia
Explanation:The posterior triangle (or lateral cervical region) is a region of the neck which has the following boundaries:
Apex: Union of the sternocleidomastoid and the trapezius muscles at the superior nuchal line of the occipital bone
Anterior: Posterior border of the sternocleidomastoid muscle
Posterior: Anterior border of the trapezius
Base: Middle one third of the clavicle
Roof: Investing layer of the deep cervical fascia
Floor: The anterolateral portion of prevertebral fascia -
This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 85
Incorrect
-
 A 45-year-old man presented to the doctor complaining of a flank pain and episodes of haematuria. Abdominal ultrasound revealed a left renal mass and the patient underwent a nephrectomy. Histopathological pattern was triphasic with blastemal, epithelial, and stromal components. The pathologist suggested the tumour resulted from the lack of a tumour suppressor gene on chromosome 11. Which of the following tumours is the pathologist most likely suggesting?
Your Answer:
Correct Answer: Wilms’ tumour
Explanation:Wilms’ tumour is one of the most common malignant tumours of childhood but it can also rarely be found in adults. In biopsy, classical histopathological findings include the triphasic pattern composed by blastemal, epithelial, and stromal elements. First symptoms in children include an abdominal palpable mass, while in adults pain and haematuria are the most common complaints. Deletions of tumours’ suppressor genes on chromosome 11 are usually associated with Wilms’ tumour.
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This question is part of the following fields:
- Pathology
- Renal
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Question 86
Incorrect
-
Which of the following organelles have the capacity to regenerate and spontaneously replicate?
Your Answer:
Correct 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 87
Incorrect
-
A 56-year-old man undergoes tests to determine his renal function. His results over a period of 24 hours were:
Urine flow rate: 2. 0 ml/min
Urine inulin: 1.0 mg/ml
Plasma inulin: 0.01 mg/ml
Urine urea: 260 mmol/l
Plasma urea: 7 mmol/l
What is the glomerular filtration rate?Your Answer:
Correct Answer: 200 ml/min
Explanation:Glomerular filtration rate (GFR) is the volume of fluid filtered from the renal (kidney) glomerular capillaries into the Bowman’s capsule per unit time. GFR is equal to the inulin clearance because inulin is freely filtered into Bowman’s capsule but is not reabsorbed or secreted. The clearance (C) of any substance can be calculated as follows: C = (U × V)/P, where U and P are the urine and plasma concentrations of the substance, respectively and V is the urine flow rate. Thus, glomerular filtration rate = (1.0 × 2. 0)/0.01 = 200 ml/min.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 88
Incorrect
-
Which of the following arteries, that runs on the superior aspect of the first part of the duodenum, forms the lower boundary of the epiploic foramen (also known as the foramen of Winslow)?
Your Answer:
Correct Answer: Hepatic
Explanation:The epiploic foramen is an important anatomical opening that allows for the communication between the greater peritoneal sac and the lesser peritoneal sac. Its boundaries are formed; superiorly by the caudate lobe of the liver, anteriorly by the hepatoduodenal ligament (containing the components of the portal triad), inferiorly by the first part of the duodenum and posteriorly by the peritoneum covering the inferior vena cava. The superior aspect of the first part of the duodenum, which forms the inferior boundary of the foramen of Winslow, forms the course of the hepatic artery before it ascends to the porta hepatis where it divides into its right and left branches.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 89
Incorrect
-
A 6 year-old boy is brought to you coughing. He is suspected to have aspirated a Lego piece which he was seen playing with. Where would you expect the piece to be?
Your Answer:
Correct Answer: Right main bronchus
Explanation:Inhaled objects are more likely to enter the right lung for several reasons. First the right bronchus is shorter, wider and more vertical than the left bronchus. Also, the carina (a ridge-like structure at the point of tracheal bifurcation) is set a little towards the left. The terminal bronchiole is a very small space and impossible for the seed to lodge here.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 90
Incorrect
-
A 26-year-old female sought consultation due to excessive vaginal discharge. Vaginal smear showed numerous bacilli under the microscope. The organism was non-pathogenic. What is the most likely organism:
Your Answer:
Correct Answer: Lactobacillus species
Explanation:Lactobacillus is a Gram-positive facultative bacteria. It is commonly present in the vagina and the gastrointestinal tract. Colonization of Lactobacillus is usually benign and it makes up a small portion of the gastrointestinal flora.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 91
Incorrect
-
What best describes the muscles of the posterior compartment of the leg?
Your Answer:
Correct Answer: One of the posterior compartment leg muscles laterally rotates the femur
Explanation:The muscles of the back of the leg are subdivided into two groups: superficial and deep. Superficial muscles include gastrocnemius, soleus and plantaris and are the chief extensors of the foot at the ankle joint. Deep muscles include the tibialis posterior, flexor hallucis longus, flexor digitorum longus and popliteus
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 92
Incorrect
-
The superior rectal artery is a continuation of the:
Your Answer:
Correct Answer: Inferior mesenteric artery
Explanation:The superior rectal artery or superior haemorrhoidal artery is the continuation of the inferior mesenteric artery. It descends into the pelvis between the layers of the mesentery of the sigmoid colon, crossing the left common iliac artery and vein.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 93
Incorrect
-
Tumours derived from all three germ-cell layers in new-borns usually occur in which of the following sites?
Your Answer:
Correct 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 94
Incorrect
-
Whipple's procedure involves mobilizing the head of the pancreas. As the surgeon does this, he must be careful to avoid injury to a key structure that is found lying behind the head of the pancreas. Which vital structure is this?
Your Answer:
Correct Answer: Common bile duct
Explanation:The posterior relations of the head of the pancreas include: the inferior vena cava, the common bile duct, the renal veins, the right crus of the diaphragm and the aorta.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 95
Incorrect
-
Calculate the stroke volume in an adult male with the following parameters:
Heart rate 70 beats/min
Arterial [O2] 0.24 ml O2/min
Venous [O2] 0.16 ml O2/mi
Whole body O2 consumption 500 ml/min
Pulmonary diastolic pressure 15 mmHg
Pulmonary systolic pressure 25 mmHg
Wedge pressure 5 mmHg.Your Answer:
Correct Answer: 90 ml
Explanation:Fick’s principle states that, 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. Cardiac output is also given by product of stroke volume and heart rate. Thus, stroke volume = cardiac output / heart rate = 6.25/70 × 1000 stroke volume = 90 ml approximately.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 96
Incorrect
-
Post-total gastrectomy, there will be a decreased production of which of the following enzymes?
Your Answer:
Correct Answer: Pepsin
Explanation:Pepsin is a protease that is released from the gastric chief cells and acts to degrade proteins into peptides. Released as pepsinogen, it is activated by hydrochloric acid and into pepsin itself. Gastrin and the vagus nerve trigger the release of pepsinogen and HCl when a meal is ingested. Pepsin functions optimally in an acidic environment, especially at a pH of 2.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 97
Incorrect
-
A 15 month old boy has a history of repeated bacterial pneumonia, failure to thrive and a sputum culture positive for H.influenzea and S.pneumoniae. There is no history of congenital anomalies. He is most likely suffering from?
Your Answer:
Correct Answer: X-linked agammaglobulinemia
Explanation:Recurrent bacterial infections may be due to lack of B-cell function, consequently resulting in a lack of gamma globulins production. Once the maternal antibodies have depleted, the disease manifests with greater severity and is called x-linked agammaglobulinemia also known as ‘X-linked hypogammaglobulinemia’, ‘XLA’ or ‘Bruton-type agammaglobulinemia. it is a rare x linked genetic disorder that compromises the bodies ability to fight infections.
Acute leukaemia causes immunodeficiency but not so specific.
DiGeorge syndrome is due to lack of T cell function.
Aplastic anaemia and EBV infection does not cause immunodeficiency.
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This question is part of the following fields:
- Inflammation & Immunology; Respiratory
- Pathology
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Question 98
Incorrect
-
A recognised side-effect of prefrontal leukotomy is:
Your Answer:
Correct Answer: Confusion
Explanation:Used previously as a treatment for psychiatric disorders, prefrontal leucotomy severs the connection between the prefrontal cortical association area and the thalamus. This leads to functional isolation of the prefrontal and orbitofrontal association cortex. Thus, along with the desired reduction in anger and frustration, undesirable side effects included changes in mood and affect, as well as confusion.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 99
Incorrect
-
A 12-year old girl was brought to the hospital with recurrent headaches for 6 months. Her physical examination revealed no abnormality. A CT scan of the head revealed a suprasellar mass with calcifications, eroding the surrounding sella turcica. The lesion is likely to represent:
Your Answer:
Correct Answer: Craniopharyngioma
Explanation:Craniopharyngiomas (also known as Rathke pouch tumours, adamantinomas or hypophyseal duct tumours) affect children mainly between the age of 5 and 10 years. It constitutes 9% of brain tumours affecting the paediatric population. These are slow-growing tumours which can also be cystic, and arise from the pituitary stalk, specifically the nests of epithelium derived from Rathke’s pouch. Histologically, this tumour shows nests of squamous epithelium which is lined on the outside by radially arranged cells. Calcium deposition is often seen with a papillary type of architecture.
ACTH-secreting pituitary adenomas are rare and mostly microadenomas. Paediatric astrocytoma’s usually occur in the posterior fossa. Although null cell adenomas can cause mass effect and give rise to the described symptoms, they are not suprasellar. Prolactinomas can also show symptoms of headache and disturbances in the visual field, however they are known to be small and slow-growing.
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This question is part of the following fields:
- Endocrine
- Pathology
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Question 100
Incorrect
-
A 24-year-old patient with recurrent episodes of deep vein thrombosis presents again to the clinic. Deficiency of which of the following blood proteins is the most probable cause of this episode?
Your Answer:
Correct Answer: Antithrombin III
Explanation:Antithrombin III (ATIII) is a blood protein that acts by inhibiting blood coagulation by neutralizing the enzymatic activity of thrombin.
Antithrombin III deficiency is an autosomal dominant disorder that leads to an increased risk of venous and arterial thrombosis. Clinical manifestations typically appear in young adulthood.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 101
Incorrect
-
The prostatic plexus of nerves contains nerve fibres that innervate penile tissue allowing for erection. From which of the following nerves do these fibres originate?
Your Answer:
Correct Answer: Pelvic splanchnics
Explanation:Pelvic splanchnic nerves are examples of the parasympathetic nerves that innervate the smooth muscle and glands of the pelvic viscera. They are also the nerves contributing fibres to the prostatic plexus which innervate penile erectile tissue.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 102
Incorrect
-
What is the primary function of the Kupffer cells found in the liver?
Your Answer:
Correct Answer: Recycling of old red blood cells
Explanation:Kupffer cells found in the liver are part of the monocyte-reticular system. They are specialised macrophages and primarily function to recycle old and damaged RBCs. The RBCs are phagocytosed and the haemoglobin is broken down into haem and globin. The haem is further broken down into iron that is recycled and bilirubin that is conjugated with glucuronic acid and excreted in the bile.
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This question is part of the following fields:
- Inflammation & Immunology; Hepatobiliary
- Pathology
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Question 103
Incorrect
-
Following a bee sting, a women develops a 2cm red, raised, swollen lesion at the site of the sting . Which of the following findings is likely to be seen in this lesion?
Your Answer:
Correct Answer: Vasodilation
Explanation:Inflammation is the immediate response of the body towards infections or irritations. The cardinal signs of inflammation are 1. redness/rubor, 2. tumour/swelling, 3.dolar/pain, 4.calor/heat and organ dysfunction (function laesa). Inflammation has 2 components; vascular and cellular. Blood vessels dilate upstream of the inflamed area leading to the rubor and calor and constrict downstream, increasing pressure and causing fluid to leak out of the capillary, resulting in swelling. The cellular component includes infiltration by neutrophils. Leukocyte arrival and functions include; 1. margination: cells marginated 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 resulting in adhesion, 4. diapedesis and chemotaxis: diapedesis is the transmigration of the leukocyte across the endothelium of the capillary and towards a chemotactic product and 5. phagocytosis: engulfing the offending substance/cell.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 104
Incorrect
-
A 60-year-old female has sudden onset of high-grade fever associated with cough with productive rusty-coloured sputum. Chest x-ray showed left-sided consolidation. What is the most accurate test for the diagnosis of this patient?
Your Answer:
Correct Answer: Sputum culture
Explanation:Sputum culture is used to detect and identify the organism that are infecting the lungs or breathing passages.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 105
Incorrect
-
The circle of Willis is an arterial anastomosis in the base of the brain and is one of the cerebrovascular safeguards in the brain. Where is the circle of Willis contained?
Your Answer:
Correct Answer: Cisterna basalis
Explanation:Cisterns refers to a system of intercommunicating pools formed by the subarachnoid space at the base of the brain and around the brainstem. Cisterna basalis/basal cistern (interpeduncular cistern) is found at the base of the brain between the two temporal lobes and it contains the arterial circle of Willis. The lumbar cistern is contained in the spinal canal while the foramen magna refers to the opening at the base of the skull though which the spinal cord enters into the skull.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 106
Incorrect
-
A 34-year-old woman is diagnosed with cerebral oedema after suffering a severe head trauma. Which of the following conditions is not likely to be associated with the extracellular oedema?
Your Answer:
Correct Answer: Increased plasma colloid osmotic pressure
Explanation:Cerebral oedema is extracellular fluid accumulation in the brain. Increased capillary permeability, increased capillary pressure, increased interstitial fluid colloid osmotic pressure and lymphatic blockage would increase fluid movement into the interstitial spaces. Increased plasma colloid osmotic pressure, however, would oppose fluid movement from the capillaries into the interstitial compartment.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 107
Incorrect
-
Which muscle would be affected most following injury to the transverse cervical artery?
Your Answer:
Correct Answer: Trapezius
Explanation:The latissimus dorsi receives blood from the thoracodorsal artery, the supraspinatus receives its blood from the suprascapular artery, the levator scapulae and the rhomboids are supplied by the dorsal scapular artery and the transverse cervical artery supplies blood to the trapezius.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 108
Incorrect
-
Lung compliance is increased by:
Your Answer:
Correct Answer: Emphysema
Explanation:Lung compliance is increased by emphysema, acute asthma and increasing age and decreased by alveolar oedema, pulmonary hypertension, atelectasis and pulmonary fibrosis.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 109
Incorrect
-
A 45-year-old man with short bowel syndrome requires parenteral nutrition. The solution of choice for parenteral nutrition is:
Your Answer:
Correct Answer: Crystalline amino acids
Explanation:Total parenteral nutrition (TPN), is the practice of feeding a person intravenously, circumventing the gut. It is normally used in the following situations: surgery, when feeding by mouth is not possible, when a person’s digestive system cannot absorb nutrients due to chronic disease or if a person’s nutrient requirement cannot be met by enteral feeding and supplementation. A sterile bag of nutrient solution, between 500 ml and 4L, is provided. The pump infuses a small amount (0.1–10 ml/h) continuously to keep the vein open. The nutrient solution consists of water, glucose, salts, amino acids, vitamins and sometimes emulsified fats. Ideally each patient is assessed individually before commencing on parenteral nutrition, and a team consisting of doctors, nurses, clinical pharmacists and dietitians evaluate the patient’s individual data and decide what formula to use and at what rate.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 110
Incorrect
-
During clinic, a medical student conducts a physical examination on a teenage boy with a lump in the inguinal region. The lump is protruding from the superficial inguinal ring. The student correctly concluded that it was:
Your Answer:
Correct Answer: Either a direct or an indirect inguinal hernia
Explanation:It is not possible to tell if an inguinal hernia is direct or indirect just by palpating it. Despite the fact that indirect inguinal hernias commonly come out of the superficial inguinal ring to enter the scrotum, direct inguinal hernia might still do this.
Femoral hernia goes through the femoral ring into the femoral canal (has nothing to do with the superficial inguinal ring).
Superficial inguinal lymph nodes lie in the superficial fascia parallel to the inguinal ligament; it would therefore feel more superficial and would not be mistaken for a hernia protruding through the inguinal ring.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 111
Incorrect
-
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:
Correct 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 112
Incorrect
-
Which tumour marker is associated with medullary carcinoma of thyroid?
Your Answer:
Correct Answer: Calcitonin
Explanation:Medullary carcinoma of thyroid accounts for 3% of thyroid cancers. It arises from the parafollicular cells (C cells) of the thyroid gland that produce calcitonin. It is often familial and caused by mutation of ret proto-oncogene, but can occasionally be sporadic. The familial cases can also occur as part of MEN syndromes IIA and IIB. The high calcitonin leads to down-regulation of the receptors, which does not affect the calcium levels significantly. Medullary carcinoma of thyroid shows characteristic amyloid deposits that stain positively with Congo red. The initial presentation consists of an asymptomatic thyroid nodule. Many cases are diagnosed due to routine screening of relatives of patients with MEN IIA and IIB. Medullary carcinoma can also cause ectopic production of other hormones/peptides such as adrenocorticotrophic hormone, vasoactive intestinal polypeptide, kallikreins and serotonin.
Metastasis from medullary carcinoma spread via the lymphatics to cervical and mediastinal nodes, and can also affect the liver, lungs and bone. Diagnosis is by raised serum calcitonin levels. A provocative test with calcium (15 mg/kg intravenously over 4 hours) also aids in diagnosis by leading to excessive secretion of calcitonin. X-ray might also show dense, conglomerate calcification.
CA-125 is frequently elevated in ovarian carcinomas. CA 15-3 is often associated with breast carcinomas. Alpha-fetoprotein is seen raised in hepatomas and gonadal tumours. Elevated HCG is associated with normal pregnancies, gonadal tumours, and choriocarcinomas. Thyroglobulin is used for surveillance in papillary carcinoma of thyroid. CA 19-9 is used in the management of pancreatic cancer.
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This question is part of the following fields:
- Endocrine
- Pathology
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Question 113
Incorrect
-
The absence of which of the following components characterizes the grey platelet syndrome (GPS)?
Your Answer:
Correct Answer: Alpha granules
Explanation:Grey platelet syndrome (GPS) is a rare inherited bleeding disorder associated with an almost total absence of α-granules and their contents. The syndrome is characterised by thrombocytopenia, enlarged platelets that have a grey appearance, myelofibrosis, and splenomegaly. Alpha granules store proteins and growth factors that promote platelet adhesiveness and wound healing. Patients with GPS develop symptoms and signs such as easy bruising, prolonged bleeding, and nose bleeds.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 114
Incorrect
-
A 40 year old man suffered severe trauma following a MVA. His BP is 72/30 mmhg, heart rate of 142 beats/mins and very feeble pulse. He was transfused 3 units of blood and his BP returned to 100/70 and his heart rate slowed to 90 beats/min. What decreased after transfusion?
Your Answer:
Correct Answer: Total peripheral resistance
Explanation:The patient is in hypovolemic shock, he is transfused with blood, this fluid resuscitation will result in a decreased sympathetic discharge and adequate ventricular filling which will result in the decreases TPR with an increased CO and cardiac filling pressures
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 115
Incorrect
-
A 31 -year-old female patient had a blood gas done on presentation to the emergency department. She was found to have a metabolic acidosis and decreased anion gap. The most likely cause of these findings in this patient would be?
Your Answer:
Correct Answer: Hypoalbuminemia
Explanation:A low anion gap might be caused by alterations in serum protein levels, primarily albumin (hypoalbuminemia), increased levels of calcium (hypercalcaemia) and magnesium (hypermagnesemia) or bromide and lithium intoxication. However, the commonest cause is hypoalbuminemia, thus if the albumin concentration falls, the anion gap will also be lower. The anion gap should be corrected upwards by 2.5 mmol/l for every 10g/l fall in the serum albumin.
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This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
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Question 116
Incorrect
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During a surgical procedure involving the carotid artery, which nerve in the cervical plexus of nerves that is embedded in the carotid sheath is most susceptible to injury?
Your Answer:
Correct Answer: Ansa cervicalis
Explanation:The ansa cervicalis is a loop of nerves that are part of the cervical plexus. They lie superficial to the internal jugular vein in the carotid triangle. Branches from the ansa cervicalis innervate the sternohyoid, sternothyroid and the inferior belly of the omohyoid. The superior root of the ansa cervicalis is formed by a branch of spinal nerve C1. These nerve fibres travel in the hypoglossal nerve before leaving to form the superior root. The superior root goes around the occipital artery and then descends embedded in the carotid sheath. It sends a branch off to the superior belly of the omohyoid muscle and is then joined by the inferior root. The inferior root is formed by fibres from spinal nerves C2 and C3.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 117
Incorrect
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Which of the following arteries is the posterior branch of the external carotid artery?
Your Answer:
Correct Answer: Superficial temporal
Explanation:The external carotid artery is a branch of the common carotid artery that supplies parts of the neck, head and face. It branches off from the common carotid artery at the level of the thyroid cartilage. The external carotid, at the level of the mandible divides into the maxillary artery and the superficial temporal. The superficial temporal artery is the posterior branch of these two arteries. It starts off, somewhat, as a continuation of the external carotid artery at the substance of the parotid gland. Anterior cerebral and middle cerebral arteries are branches of the internal carotid artery.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 118
Incorrect
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In a young, sexually active male, what is the most common cause of non-gonococcal urethritis?
Your Answer:
Correct Answer: Chlamydia
Explanation:Non-gonococcal urethritis is most commonly caused by Chlamydia trachomatis (50% cases). Less common organisms include Mycoplasma genitalium, Urea urealyticum and Trichomonas vaginalis. Chlamydia is also the commonest cause of non-gonococcal cervicitis in women and proctitis in both sexes.
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This question is part of the following fields:
- Pathology
- Renal
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Question 119
Incorrect
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A 38 year-old man falls on an outstretched hand. X-rays indicate an anterior dislocation of one of the carpal bones. Which carpal bone is most commonly dislocated?
Your Answer:
Correct Answer: Lunate
Explanation:The scaphoid bone is the most commonly fractured carpal bone and has an increased risk of avascular necrosis.
The lunate is the most commonly dislocated carpal bone. The displaced bone may compress the median nerve in the carpal tunnel.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 120
Incorrect
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The circle of Willis is one of the cerebrovascular safeguards comprised of the left and the right posterior communicating artery. Which of the following arteries in the brain is connected to the posterior cerebral artery by these posterior communicating arteries?
Your Answer:
Correct Answer: Internal carotid artery
Explanation:The Circle of Willis is an anastomosis of cerebral arteries that are located at the base of the brain. The Circle of Willis is one of the important safeguards that ensure back up of blood supply to parts of the brain in case of any cerebrovascular accident. The Circle of Willis is made up of an anterior portion of arteries including; the anterior cerebral arteries. The anterior cerebral arteries are connected to the posterior portion of the circle of Willis by the anterior communicating artery. The posterior portion is made up of the posterior cerebral artery which branch off from the basilar artery. The posterior cerebral artery are connected to the anterior portion of the circle of Willis by the posterior communicating artery. The posterior communicating artery connects the posterior cerebral artery to the internal carotid artery. The circle of Willis receives blood supply from the left and right internal carotid arteries that continues as the middle cerebral artery and posteriorly from the two vertebral arteries that join to form the basilar artery.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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