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Question 1
Correct
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A butcher accidentally cut himself on his right index finger. Which of the following substances when in contact with the basement membrane of the injured vasculature will activate the coagulation cascade as well as the kinin system in a first response to this injury?
Your Answer: Hageman factor
Explanation:Hageman factor/factor XII in the intrinsic pathway activates prekallikrein and factor XI. Deficiency will not cause excessive bleeding as other coagulation factors will be utilized but the PTT will be greater than 200 seconds.
Thromboxane promotes platelet aggregation and causes vasoconstriction.
Plasmin, which is cleaved from plasminogen acts as an anticoagulant which breaks down thrombi.
Platelet activating factor promotes platelet aggregation and is also chemotactic to neutrophils.
Histamine acts as a vasodilator.
Platelet inhibiting factor acts an anticoagulant.
Renin is a hormone released from the kidney that causes vasoconstriction and water retention.
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This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
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Question 2
Correct
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During a radical mastectomy for advanced breast cancer, the surgeon injured the long thoracic nerve. Which among the following muscles is likely to be affected?
Your Answer: Serratus anterior
Explanation:The long thoracic nerve innervates the serratus anterior muscle which holds the scapula forward and balances the rhomboids and the trapezius muscles which retract the scapula. Injury to this nerve results in a ‘winged scapula’ with a posterior protrusion.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 3
Correct
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A 35 year old patient presenting with haematemesis, heart burn and bloody stool was diagnosed with a duodenal ulcer that had eroded the gastroduodenal artery. The patient was then rushed into theatre for an emergency procedure to control the haemorrhage. If the surgeon decided to ligate the gastroduodenal artery at its origin, which of the following arteries would most likely experience retrograde blood flow from collateral sources as a result of the ligation?
Your Answer: Right gastroepiploic
Explanation:In the stomach and around the duodenum, there are many arterial anastomoses. Ligation of the gastroduodenal artery would result in the retrograde flow of blood from the left gastroepiploic artery to the right gastroepiploic artery. The blood flows into the right gastroepiploic artery, a branch of the gastroduodenal artery from the left gastroepiploic artery that branches from the splenic artery. This retrograde blood flow is aimed at providing alternate blood flow to the greater curvature of the stomach.
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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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From which of the following cells is heparin produced?
Your Answer: Endothelial cells
Correct Answer: Mast cells
Explanation:Heparin is a natural highly-sulphated glycosaminoglycan that has anticoagulant functions. It is produced by the body basophils and mast cells.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 5
Correct
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Question 6
Incorrect
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Cyclophosphamide is used as a chemotherapy and immunosuppressant agent and is indicated in various diseases. One of the most severe complications of its use is cancer of the:
Your Answer: Liver
Correct Answer: Urinary bladder
Explanation:Cyclophosphamide is used to treat various types of cancer and autoimmune disorders. The main use of cyclophosphamide is in combination with other chemotherapy agents in the treatment of lymphomas, some forms of leukaemia and some solid tumours. Side-effects include nausea and vomiting, bone marrow suppression, stomach ache, diarrhoea, darkening of the skin/nails, alopecia, lethargy, and haemorrhagic cystitis. Cyclophosphamide is itself carcinogenic, potentially causing transitional cell carcinoma of the bladder as a long-term complication.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 7
Correct
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Which of the following toxins most likely results in continuous cAMP production, which pumps H2O, sodium, potassium, chloride and bicarbonate into the lumen of the small intestine and results in rapid dehydration?
Your Answer: Cholera toxin
Explanation:The cholera toxin (CTX or CT) is an oligomeric complex made up of six protein subunits: a single copy of the A subunit (part A), and five copies of the B subunit (part B), connected by a disulphide bond. The five B subunits form a five-membered ring that binds to GM1 gangliosides on the surface of the intestinal epithelium cells. The A1 portion of the A subunit is an enzyme that ADP-ribosylates G proteins, while the A2 chain fits into the central pore of the B subunit ring. Upon binding, the complex is taken into the cell via receptor-mediated endocytosis. Once inside the cell, the disulphide bond is reduced, and the A1 subunit is freed to bind with a human partner protein called ADP-ribosylation factor 6 (Arf6). Binding exposes its active site, allowing it to permanently ribosylate the Gs alpha subunit of the heterotrimeric G protein. This results in constitutive cAMP production, which in turn leads to secretion of H2O, Na+, K+, Cl−, and HCO3− into the lumen of the small intestine and rapid dehydration. The gene encoding the cholera toxin was introduced into V. cholerae by horizontal gene transfer.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 8
Correct
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A machine worker fractured the medial epicondyle of his right humerus resulting in damage to an artery running with the ulnar nerve posterior to the medial epicondyle. The artery injured is the?
Your Answer: Superior ulnar collateral
Explanation:The superior ulnar collateral artery runs posterior to the medial epicondyle of the humerus, accompanied by the ulnar nerve. This artery arises from the brachial artery near the middle of the arm and ends under the flexor carpi ulnaris muscle by anastomosing with two arteries: the posterior ulnar recurrent and inferior ulnar collateral.
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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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During an operation to repair an aortic coarctation in a neonate, a surgeon accidentally cuts the first aortic intercostal arteries as he mobilised the descending aorta. Which one of the following structure might be deprived of its primary source of blood supply following this injury?
Your Answer: Right bronchus
Explanation:The right bronchus is supplied by one right bronchial artery that may branch from one of the left bronchial arteries or from the right 3rd posterior intercostal artery (this is the first intercostal artery that arises from the aorta). Damage to this artery might stop blood supply to the main bronchus. Intercostal arteries that go to the first and the second interspaces originate from the highest intercostal artery such that blood supply to either of these spaces would not be interfered with.
The left bronchus receives blood from 2 left bronchial arteries which are direct branches from the descending aorta.
Fibrous pericardium is the sac that contains the heart. Its blood supply is not a major concern.
Visceral pericardium receives its blood supply from the coronary vessels.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 10
Correct
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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: 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 11
Correct
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A drug abuser developed an infection which spread from the dorsum of the hand to the medial side of the arm along the course of the large cutaneous vein. Which vein is involved?
Your Answer: Basilic
Explanation:The basilic vein is one of two veins found in the forearm, the other is the cephalic vein. These veins originate from the deep venous arch of the hand. The cephalic vein ascends along the lateral side of the forearm, and the basilic vein runs up the medial side of the forearm.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 12
Correct
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Which of the following has the least malignant potential?
Your 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 13
Correct
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What are the derivatives of the first brachial arch?
Your Answer: Gives rise to the sphenomandibular ligament
Explanation:The first brachial arch (mandibular) gives rise to the mandibular and maxillary processes. Muscles and bones of this process originate within the arch’s mesoderm. The first arch cartilage (Meckel’s) ossifies to form the incus and malleus of the middle ear. Its perichondrium gives rise to he sphenomandibular ligament and through intermembraneous ossification after the mandible forms, the rest of the cartilage disappears. Muscles of the first arch include: mylohyoid, tensor tympany and palati, temporalis, masseter and lateral pterygoids and the anterior belly of the epigastric. This first arch is supplied by the trigeminal nerve.
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This question is part of the following fields:
- Anatomy
- Embryology
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Question 14
Correct
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Diuretics that act on the ascending limb of the loop of Henle produce:
Your Answer: Reduced active transport of sodium
Explanation:The loop of Henlé leads from the proximal convoluted tubule to the distal convoluted tubule. Its primary function uses a counter current multiplier mechanism in the medulla to reabsorb water and ions from the urine. It can be divided into four parts:
1. Descending limb of loop of Henl̩ Рlow permeability to ions and urea, while being highly permeable to water
2. Thin ascending limb of loop of Henl̩ Рnot permeable to water, but it is permeable to ions
3. Medullary thick ascending limb of loop of Henlé – sodium (Na+), potassium (K+) and chloride (Cl–) ions are reabsorbed by active transport. K+ is passively transported along its concentration gradient through a K+ channel in the basolateral aspect of the cells, back into the lumen of the ascending limb.
4. The cortical thick ascending limb – the site of action where loop diuretics such as furosemide block the K+/Na+/2Cl− co-transporters = reduced active transport.
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This question is part of the following fields:
- Physiology
- Renal
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Question 15
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 16
Incorrect
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Raised alkaline phosphatase and positive antimitochondrial antibody indicates which of the following conditions presenting with pruritus?
Your Answer: Sclerosing cholangitis
Correct Answer: Primary biliary cirrhosis
Explanation:An autoimmune disease, primary biliary cirrhosis results in destruction of intrahepatic bile ducts. This leads to cholestasis, cirrhosis and eventually, hepatic failure. Symptoms includes fatigue, pruritus and steatorrhea. Increased IgM levels, along with antimitochondrial antibodies are seen in the serum. Liver biopsy is diagnostic, and also aids in staging of disease.
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This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
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Question 17
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 18
Incorrect
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Which of the following muscles aid in inspiration?
Your Answer: Diaphragm, internal and external intercostals
Correct Answer: Diaphragm and external intercostals
Explanation:The diaphragm and external intercostals are muscles of inspiration as they increase the volume of thoracic cavity and reduce the intrathoracic pressure. Muscles of expiration include abdominal muscles and internal intercostals.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 19
Correct
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A 30 year old man suffered severe blood loss, approx. 20-30% of his blood volume. What changes are most likely seen in the pulmonary vascular resistance (PVR) and pulmonary artery pressure (PAP) respectively following this decrease in cardiac output?
Your Answer: Increase Decrease
Explanation:Hypovolemia will result in the activation of the sympathetic adrenal discharge resulting is a decrease pulmonary artery pressure and an elevated pulmonary vascular resistance.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 20
Correct
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The line which divides the perineum into two triangles is connected to the?
Your Answer: Ischial tuberosities
Explanation:The perineum has it’s deep boundaries in front of the pubic arch and the arcuate ligament of the pubis, behind the tip of the coccyx and on either side of the inferior rami of the pubis and ischium and the sacrotuberous ligament. It also corresponds to the outlet of the pelvis. A line drawn transversely across, in front of the ischial tuberosities divides the space into two portions, the posterior contains the termination of the anal canal and the anterior, contains the external urogenital organs.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 21
Incorrect
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Cancer of the testis most likely metastases to which set of lymph nodes?
Your Answer: Superficial inguinal
Correct Answer: Aortic
Explanation:The lymphatic drainage of an organ is related to its blood supply. The lymphatic drainage of the testis drains along the testicular artery to reach the lymph nodes along the aorta.
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This question is part of the following fields:
- Endocrine
- Pathology
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Question 22
Correct
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A 30-year-old woman known with Von Willebrand disease (vWD) has to undergo surgery. Which of these complications is most unlikely in this patient?
Your Answer: Hemarthrosis
Explanation:Von Willebrand disease (vWD) is an inherited haemorrhagic disorder characterised by the impairment of primary haemostasis. It is caused by the deficiency or dysfunction of a protein named von Willebrand factor. The most common manifestation due to the condition is abnormal bleeding. Complications include easy bruising, hematomas, epistaxis, menorrhagia, prolonged bleeding and severe haemorrhage. Hemarthrosis is a complication that is more commonly found in haemophilia.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 23
Incorrect
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What is the normal glomerular filtration rate?
Your Answer: 75 mL/min
Correct Answer: 125 mL/min
Explanation:The normal glomerular filtration rate (GFR) in humans is 125 mL/min. After the age of 40, GFR decreases progressively by about 0.4–1.2 mL/min per year.
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This question is part of the following fields:
- Physiology
- Renal
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Question 24
Incorrect
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Which of these foramen is located at the base of the skull and transmits the accessory meningeal artery?
Your Answer: Foramen spinosum
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 25
Correct
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The most likely cause of a low p(O2) in arterial blood is:
Your Answer: Hypoxic hypoxia
Explanation:Hypoxia is when the whole body or a region is deprived of adequate oxygen supply. Different types of hypoxia include the following:
– Hypoxic hypoxia, which occurs due to poor oxygen supply, as a result of low partial pressure of oxygen in arterial blood. This could be due to low partial pressure of atmospheric oxygen (e.g., at high altitude), sleep apnoea, poor ventilation because of chronic obstructive pulmonary disease or respiratory arrest, or shunts. The other types of hypoxia have a normal partial pressure of oxygen.
– Anaemic hypoxia occurs due to low total oxygen content of the blood, with a normal arterial oxygen pressure.
– Hyperaemic hypoxia occurs due to poor delivery of oxygen to target tissues, such as in carbon monoxide poisoning or methemoglobinemia.
– Histotoxic hypoxia results due to inability of the cells to use the delivered oxygen due to disabled oxidative phosphorylation enzymes.
– Ischaemic (or stagnant) hypoxia occurs due to local flow restriction of well-oxygenated blood, seen in cases like cerebral ischaemia, ischaemic heart disease and intrauterine hypoxia.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 26
Correct
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A diabetic 58-year-old man, after the injection of radiographic contrast, has a decreased urine output and decreased level of consciousness. Which of the following conditions has he most likely developed
Your Answer: Acute tubular necrosis
Explanation:Acute tubular necrosis (ATN) involves damage to the tubule cells of the kidneys and is the most common cause of acute kidney injury. ATN in the majority of the cases is caused by ischaemia of the kidneys due to lack of perfusion and oxygenation but it may also occur due to poison or harmful substance. Contrast used for radiology may cause ATN in patients with several risk factors e.g. diabetic nephropathy. Symptoms may include oliguria, nausea, fluid retention, fatigue and decreased consciousness.
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This question is part of the following fields:
- Pathology
- Renal
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Question 27
Correct
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The histological exam of a tuberculous granuloma shows a periphery of multinuclear giant cells, with a central area of:
Your Answer: Caseous necrosis
Explanation:Granulomas with necrosis tend to have an infectious cause. The chronic infective lesion in this case typically presents with a central area of caseous (cheese-like) necrosis. Foam cells are the fat-laden M2 macrophages seen in atherosclerosis
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This question is part of the following fields:
- Cell Injury & Wound Healing; Dermatology
- Pathology
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Question 28
Incorrect
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A 46 -year old patient diagnosed with chronic rhinosinusitis, was to undergo surgery to improve drainage from his frontal sinus to the nose. Which is a route that one would take to enter into the frontal sinus through the nasal cavity?
Your Answer: Superior meatus
Correct Answer: Middle meatus
Explanation:The middle meatus is a nasal passageway located inferior to the middle concha and superior to the inferior concha. On the superior aspect of this meatus is a bulge produced by the middle ethmoidal cells known as the bulla ethmoidalis. Below this bulge is a curved fissure, the hiatus semilunaris, which is also bordered inferiorly by the edge of the uncinate process of the ethmoid. It is through this curved fissure, hiatus semilunaris, that the middle meatus communicates with the frontal sinus. It first forms a communication with a curved passage way known as the infundibulum. The infundibulum anteriorly communicates with the anterior ethmoidal cells and continues upward as the frontonasal duct into the frontal sinus.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 29
Correct
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Where would you insert the needle when drawing blood from a patient's median cubital vein?
Your Answer: Anterior aspect of the elbow
Explanation:The correct answer is to insert it into the anterior aspect of the elbow. If you look at the venous drainage of the upper limb, you will find that there are two main veins, the basilic and the cephalic vein; the connecting branch between these two veins is the median cubital vein. and this vein passes via the cubital fossa which is on the anterior aspect of the forearm.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 30
Correct
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Which organs would cause pain in a patient who complains of dull pain in her pelvis, along the midline starting from the pubic bone in the front to the sacrum at the back?
Your Answer: Urinary bladder, uterus/cervix/vagina, rectum
Explanation:The pain could have been caused by the urinary bladder, uterus/cervix/vagina or rectum as it involves the pelvic viscera.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 31
Correct
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A 50 year old man was admitted to the surgical ICU following a hemicolectomy for carcinoma of the caecum. A full blood count revealed: haematocrit = 30%, erythrocytes = 4 × 106/μ, haemoglobin level = 8 g/dl. To determine the likely cause of his anaemia, red blood cell indices were calculated. Which RBC indices are correct?
Your Answer: MCHC = haemoglobin concentration/haematocrit
Explanation:Mean corpuscular haemoglobin concentration (MCHC) is calculated simply by dividing the haemoglobin concentration (8 g/dl) by the haematocrit (0.3). The normal range is 31–36 g/dl. This patient has a hypochromic anaemia (MCHC = 8/0.3 = 26.7 g/dl). Dividing the haemoglobin concentration × 10 by erythrocyte number yields mean corpuscular haemoglobin (MCH). Normal range is 25.4–34.6 pg/cell and this patient has a significantly reduced cellular haemoglobin content (MCH = 8 × 10/4 = 20 pg/cell). Mean corpuscular volume (MCV) is calculated by dividing haematocrit × 1000 by erythrocyte number (4 × 106/μl). Normal range is 80–100 fl and this patient has a microcytic anaemia (MCV = 0.3 × 1000/4 = 75 fl). Microcytic, hypochromic anaemia is characteristic for iron-deficiency.
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This question is part of the following fields:
- General
- Physiology
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Question 32
Incorrect
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What is the primary function of the Kupffer cells found in the liver?
Your Answer: Synthesis of intrinsic factor
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 33
Incorrect
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A brain tumour causing blockage of the hypophyseal portal system is likely to result in an increased secretion of which of the following hormones?
Your Answer: Adrenocorticotrophic hormone
Correct Answer: Prolactin
Explanation:The hypophyseal portal system links the hypothalamus and the anterior pituitary. With the help of this system, the anterior pituitary receives releasing and inhibitory hormones from the hypothalamus and regulates the action of other endocrine glands. One of the inhibitory hormones carried by this system is the prolactin-inhibitory hormone. In the absence of this hormone which might occur in case of a blockage of the system, prolactin secretion increases to about three times normal levels.
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This question is part of the following fields:
- Endocrinology
- Physiology
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Question 34
Correct
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When a patient is standing erect, pleural fluid would tend to accumulate in which part of the pleural space?
Your Answer: Costodiaphragmatic recess
Explanation:The costo-diaphragmatic recess is the lowest extent of the pleural cavity or sac. Any fluid in the pleura will by gravity accumulate here when a patient is standing erect.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 35
Correct
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A 40 year old patient with an history of obesity has been diagnosed with meralgia parasthetica. The condition was discovered to be caused by the pinching of the lateral femoral cutaneous nerve. Injuries at what spinal levels usually affect this nerve?
Your Answer: L2, L3
Explanation:The lateral femoral cutaneous nerve of the thigh arises from the dorsal division of the lumbar plexus of the second and the third lumbar nerves (L2 – L3). Spinal injuries at this level are likely to affect the lateral femoral cutaneous nerve. The lateral femoral cutaneous nerve innervates the skin on the lateral aspect of the thigh.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 36
Correct
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What is the arterial sequence for an analgesic to reach the latissimus dorsi muscle assuming that your starting point is at the subclavian vein?
Your Answer: Subclavian – axillary – subscapular – thoracodorsal
Explanation:Assuming our starting point is the subclavian artery, the analgesic continues in the same vessel into the axillary artery, as it passes into the axilla. The axillary artery at the lower border of the subscapularis gives rise to the subcapsular artery which is considered the largest branch of the axillary artery. This circumflex scapular branch distributes a serratus branch before entering the substance of the muscle as the thoracodorsal artery.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 37
Correct
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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: 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 38
Correct
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A previously healthy 40-year-old housewife suddenly complains of a headache and loses consciousness. A CT scan reveals subarachnoid haemorrhage. Which of the following is the most probable cause?
Your Answer: Ruptured berry aneurysm
Explanation:Saccular aneurysms, also known as berry aneurysms, appear as a round outpouching and are the most common form of cerebral aneurysm. They are a congenital intracranial defect, and haemorrhage can occur at any age, but is most common between the ages of 40-65 years. A second rupture (rebleeding) sometimes occurs, most often within about 7 days of the first bleed.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 39
Correct
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Gram positive bacteria differ from gram negative bacteria due to the presence of which of the following structures?
Your Answer: Outer membrane
Explanation:The reason bacteria are either Gram-positive or Gram-negative is due to the structure of their cell envelope (the cell envelope is defined as the cell membrane and cell wall plus an outer membrane, if one is present.) Gram-positive bacteria, for example, retain the crystal violet due to the amount of peptidoglycan in the cell wall. It can be said therefore that the Gram-stain procedure separates bacteria into two broad categories based on structural differences in the cell envelope.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 40
Correct
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Bile salt reuptake principally occurs where?
Your Answer: In the ileum
Explanation:90 – 95% of the bile salts are absorbed from the small intestine (mostly terminal ileum and then excreted again from the liver. This is known as the enterohepatic circulation. The entire pool recycles twice per meal and approximately 6 to 8 times per day.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 41
Correct
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A 60 year old female patient who has suffered an embolic stroke that affected her middle cerebral artery as revealed by a CT scan is likely to exhibit which of the following neurologic conditions?
Your Answer: Contralateral hemiplegia
Explanation:The middle cerebral artery is a major artery that supplies blood to the cerebrum. It continues from the internal carotid artery up into the lateral sulcus. The middle cerebral artery mainly supplies the lateral aspect of the cerebral cortex, anterior aspect of the temporal lobes and the insular cortices.
Functional areas supplied by this vein are as follows:
The motor and pre-motor areas
The somato-sensory
Auditory areas
Motor speech
Sensory speech
Pre-frontal area
Occlusion of the middle cerebral artery results in:
i) A severe contralateral hemiplegia, most marked in the upper extremity and face
ii) A contralateral sensory impairment worse in the upper part of the body.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 42
Correct
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A histopathological analysis of a specimen showed loss of individual cell structure with karyorrhexis and fragmentation. The overall integrity of the tissue structure is preserved. This is typical of which of the following pathologies?
Your Answer: Viral hepatitis
Explanation:Viral infections will cause necrosis of the hepatocytes with characteristic changes of karyorrhexis and cell fragmentation.
Brown atrophy of the heart is due to accumulation of lipofuscin in the myocardium.
Tissue destruction associated with transplant rejection leads to widespread loss of structural integrity.
Single cell necrosis is not characteristically seen in chronic alcoholic liver.
Barbiturate overdose will result in hypertrophy of the smooth endoplasmic reticulum.
Carcinoma insitu will cause dysplastic cells without the overall structural integrity being disrupted.
Atrophy is due to apoptosis with ordered cellular fragmentation and phagocytosis and will not induce an inflammatory process unlike necrosis.
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This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
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Question 43
Correct
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A 30 year old lawyer presented with a history of pleural effusions, pericarditis, arthralgia without joint deformity and episodes of myalgia for the past 12 months. Blood tests reveal a normocytic anaemia. Which of the following tests should be performed to investigate this condition further?
Your Answer: Antinuclear antibody test
Explanation:These non specific findings are suggestive of autoimmune disease. Antinuclear antibody (ANA) is the first test that should be performed when autoimmune diseases are suspected and later on more specific tests should be performed. This tests aids in the diagnosis of SLE, scleroderma, Sjogren’s syndrome, Raynaud’s disease, juvenile chronic arthritis, rheumatoid arthritis and antiphospholipid antibody syndrome etc. To confirm the disease a history, physical examination along with specific tests are required.
CPK is more specific for acute conditions.
ESR is a non specific test for inflammation.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 44
Correct
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A 32-year old gentleman came to the emergency department, complaining of progressively increasing weakness in his arms and legs over 5 days. On examination, there is symmetrical weakness on both sides of his face, along with weakness of the proximal and distal muscles of all four limbs. No loss of sensation noted. Deep tendon reflexes could not be elicited and plantar responses were downward. On enquiry, it was revealed that he had an upper respiratory tract infection 10 days ago. The likely diagnosis is:
Your Answer: Guillain–Barré syndrome
Explanation:Guillain–Barré syndrome (GBS) is an acute, autoimmune polyradiculoneuropathy which affects the peripheral nervous system and is usually triggered by an acute infectious process. 75% patients have a history of acute infection within the past 1–4 weeks, usually respiratory or gastrointestinal. immunisations have also been implicated. The most common form is acute inflammatory demyelinating polyneuropathy. It results in an ascending paralysis with complete loss of deep tendon reflexes. Treatment includes immunoglobulins and supportive care. However, the disease may be fatal due to severe pulmonary complications and dysautonomia.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 45
Correct
-
The cranial nerves of the brain provide motor and sensory innervation to the structures of the head and neck. Which of the following cranial nerves provide only motor innervation?
Your Answer: Abducens
Explanation:The cranial nerves emerge directly from the brain and the brain stem. They provide sensory, motor or both motor and sensory innervation. Here is a summary of the cranial nerves and their function:
Olfactory – Purely sensory
Optic – Sensory
Oculomotor – Mainly motor
Trochlear – Motor
Trigeminal – Both sensory and motor
Abducens – Mainly motor
Facial – Both sensory and motor
Vestibulocochlear – Mostly sensory
Glossopharyngeal – Both sensory and motor
Vagus – Both sensory and motor
Accessory – Mainly motor
Hypoglossal – Mainly motor
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 46
Correct
-
A 38 year old man is to undergo excision of the base of the prostate for malignant growth, which of the following structures is directly related to the base of the prostate?
Your Answer: Urinary bladder
Explanation:The prostate is situated in the pelvic cavity and is also located immediately below the internal urethral orifice at the commencement of the urethra. It is held in position by the puboprostatic ligaments, the superior fascia of the urogenital diaphragm and the anterior portions of the levatores ani. The base of the prostate is directed upward and is attached to the inferior surface of the urinary bladder while the apex is directed downward and is in contact with the superior fascia of the urogenital diaphragm.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 47
Correct
-
Which of the following diseases causes abrupt vertigo, nausea, vomiting, tinnitus, and nystagmus?
Your Answer: Vestibular neuronitis
Explanation:Vestibular neuronitis or labyrinthitis causes a self-limited episode of vertigo, presumably due to inflammation of the vestibular division of cranial nerve VIII. Its causes are unknown, It may be due to a virus, but it can be related to a bacterial infection, head injury, stress, allergy, or as a reaction to medication. Symptoms can last up to 7-10 days.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 48
Correct
-
After a car accident, a 30-year-old woman is alert and only has minor, superficial injuries. 2 hours later, she becomes unconscious and a CT scan reveals a convex, lens-shaped haemorrhage over the right parietal region. The most likely diagnosis is:
Your Answer: Epidural haematoma
Explanation:Epidural haematomas are usually caused by arterial bleeding, classically due to damage to the middle meningeal artery by a temporal bone fracture. Symptoms develop within minutes to several hours after the injury and consist of increasing headache, decreased level of consciousness, hemiparesis and pupillary dilation with loss of light reactivity. Around 15–20% of epidural hematomas are fatal.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 49
Incorrect
-
T lymphocytes that express the MCH type II antigen are most likely to produce which of the following cytokines?
Your Answer: Alpha interferon
Correct Answer: Gamma interferon
Explanation:Interferon gamma is a soluble cytokine previously known as the macrophage activating factor. It is the only member belonging to the type II class of the interferons. It is secreted by a number of cells taking part in the immune reaction including: T-helper cells (CD-4), cells with immunological memory (CD45PA), killer cells (CD8), dendrite cells (CD23,35), natural killer cells (CD16) and B lymphocytes (CD22,CD23). It has both a defending as well as a pathological effect. It induces differentiation in the myeloid cell in the bone marrow. If macrophages are infected by parasites it activates the macrophages to destroy them. IFN-γ strengthens the anti-tumour activities of the cytotoxic lymphocytes. Together with CD4 or CD8 toxins, produced by lymphocytes, it suppresses the growth of the tumour cells. along with these functions it increases the non specific response of the natural killer cells, causing changes in the cell membrane surface to prevent adhesion and penetration of a virus. It can either increase or decrease B cell response and it activates osteoclasts which increases bone resorption.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 50
Incorrect
-
Leakage from a silicone breast implant can lead to:
Your Answer: Breast abscess
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 51
Correct
-
The stomach is an organ that is divided into several important anatomical parts. These parts of the stomach have varied arterial blood supply that ensure that the whole organ receive oxygenated blood. Which of the following arteries if ligated, will not render any portion of the stomach ischaemic?
Your Answer: Superior mesenteric
Explanation:The blood supply to the stomach is through the following arteries:
– The superior mesenteric artery supplies blood to the lower part of the duodenum, pancreas and two-thirds of the transverse colon. Thus ligation of the superior mesenteric artery would not affect the stomach.
– The right and the left gastroepiploic arteries supply the greater curvature of the stomach – along its edges.
– The short gastric artery supplies blood to the upper portion of the of the greater curvature and the fundus of the stomach.
– The gastroduodenal artery supplies blood to the distal part of the stomach (the pyloric sphincter) and the proximal end of the duodenum.
– The left gastroepiploic and the short gastric are branches of the splenic artery and therefore ligation of the splenic artery would directly affect the stomach.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 52
Correct
-
What is the normal duration of PR interval on an electrocardiogram of a healthy individual?
Your Answer: 0.12–0.20 s
Explanation:PR interval extends from the beginning of the P-wave until the beginning of the QRS complex. The normal duration of the PR interval is 0.12-0.20 s. It can be prolonged in first degree heart block, and reduced in Wolff-Parkinson-White syndrome.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 53
Correct
-
A young man was thrown from a vehicle in a collision. He landed on his head and shoulder tip, stretching the left side of his neck. A neurological examination revealed that the fifth and sixth cervical nerves had been torn from the spinal cord. What is the most obvious clinical manifestation of this?
Your Answer: Abduction
Explanation:In the case of injuries to the upper roots of the brachial plexus there is complete loss of abduction. The muscle performing this movement is the supraspinatus. This initiates the movement, followed by the deltoid muscle, which allows for complete abduction. Both these muscles are innervated by nerves originating from C5 and C6. The injury to these roots results in a condition named Erb-Duchenne’s palsy.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 54
Correct
-
What is the result of maltase deficiency in the brush border of the small intestine?
Your Answer: Results in increased passage of maltose in stool
Explanation:Maltase is an enzyme produced from the surface cells of the villi, lining the small intestine and aids in hydrolysing the disaccharide maltose, which splits into two molecules of α-glucose. It is done by breaking the glycosidic bond between the ‘first’ carbon of one glucose and the ‘fourth’ carbon of the other (a 1–4 bond). Hence, a deficiency of enzyme maltase will result in the increased passage of maltose in the stool.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 55
Correct
-
A 78-year-old man who has been bedridden for a month is prescribed griseofulvin. What class of drugs does griseofulvin belong to?
Your Answer: Antifungal
Explanation:Griseofulvin is an antifungal drug. It is administered orally, and it is used to treat ringworm infections of the skin and nails. It binds to keratin in keratin precursor cells and makes them resistant to fungal infections. Griseofulvin works by interfering with fungal mitosis.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 56
Correct
-
Which of the following malignancies is likely to have the best prognosis?
Your Answer: Papillary carcinoma of the thyroid
Explanation:Papillary carcinoma accounts for 70-80% of all thyroid cancers and is seen commonly in people aged 30-60 years. It is more aggressive in elderly patients. 10-20% cases may have recurrence or persistent disease. More common in females with a female to male ratio of 3:1. Papillary carcinomas can also contain follicular carcinomas. The common route of spread is through lymphatics to regional nodes in one-third cases and pulmonary metastasis can also occur. Papillary carcinomas of the thyroid have the best prognosis, especially in patients less than 45 years of age with small tumours confined to the thyroid gland.
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This question is part of the following fields:
- Endocrine
- Pathology
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Question 57
Correct
-
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: 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 58
Incorrect
-
A patient who underwent emergency appendicectomy complains of having numbness (paraesthesia) of the skin at the pubic region. Which nerve was most likely injured in the operation?
Your Answer: Genitofemoral
Correct Answer: Iliohypogastric
Explanation:The iliohypogastric nerve comes from L1 and emerges from the upper part of the lateral border of the psoas major. It then crosses obliquely in front of the quadratus lumborum to the iliac crest where it perforates the posterior part of transversus abdominis and divides between that muscle and the internal oblique into a lateral and an anterior cutaneous branch. This provides sensory innervation to the skin of the lower abdominal wall, upper hip and upper thigh.
The genitofemoral nerve also comes from the lumbar plexus that innervates the skin of the anterior scrotum or labia majora and upper medial thigh.
The subcostal nerve is the ventral primary ramus of T12 providing sensory innervation to the anterolateral abdominal wall in an area superior to the pubic region.
A spinal nerve owing to their deep location would not have been injured in the procedure.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 59
Incorrect
-
A medical intern wanting to perform her first thoracentesis (remove fluid from the pleural cavity) wishes to be reminded where to insert the needle to aspirate in order to avoid injuring the lung or neurovascular elements. Where is this place?
Your Answer: The top of interspace 9 in the midaxillary line
Correct Answer: The bottom of interspace 9 in the midaxillary line
Explanation:Thoracentesis is performed in the costodiaphragmatic recess. The needle needs to be inserted below the level of the lungs to avoid injury to the lungs. At the paravertebral line, is between ribs 10 and 12, at the midaxillary line between ribs 8 and 10 and at the midclavicular line between interspaces 6 and 8. The needle should be inserted at the top of the rib (or the bottom of the interspace) to avoid damage to the neurovascular structures found below the rib running in the costal groove.
The recommended location for the needle insertion varies depending upon the source. It is critical that the patient hold his or her breath to avoid piercing of the lung.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 60
Correct
-
Paracentesis of ascetic fluid in a 45-year old woman revealed the following : clear, yellow fluid with protein 2.0 g/dl and a few mesothelial and mononuclear cells seen. No malignant cells seen. What is the likely diagnosis?
Your Answer: Cirrhosis
Explanation:Ascites develops either from:
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- Increased  accumulation
- Increased capillary permeability
- Increased venous pressure
- Decreased protein (oncotic pressure)
- Decreased clearance
- Increased lymphatic obstruction
- Increased  accumulation
Cause
- Transudate (<30g/L protein) (Systemic disease)
- Liver (Cirrhosis)
- Cardiac e.g. RHF, CCF, SBE right heart valve disease and constrictive Pericarditis
- Renal failure
- Hypoalbuminaemia (nephrosis)
- Exudate (>30g/L protein) (Local disease)
- Malignancy
- Venous obstruction e.g. Budd-Chiari, Schistosomiasis
- Pancreatitis
- Lymphatic obstruction
- Infection (especially TB)
Cirrhosis is disease of the liver that is characterized by fibrosis leading to disorganization of the hepatic architecture. It shows the development of regenerative nodules surrounded by dense fibrotic tissue. Cirrhosis shows non-specific symptoms initially, which include fatigue, anorexia and weight loss. It can later progress to portal hypertension, ascites and liver failure.
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This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
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Question 61
Correct
-
Injury to the supraspinatus muscle will affect:
Your Answer: Initiation of abduction of the humerus
Explanation:This muscle arises from the medial two-thirds of the supraspinatus fossa and from the supraspinatus fascia. It is inserted into the highest impression on the greater tubercle of the humerus after passing over the upper part of the shoulder joint. It works with the deltoid to raise the arm from the side of the trunk and initiate abduction. It also assists in fixation of the head of the humerus in the glenoid cavity.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 62
Incorrect
-
A pedestrian sustained a left fibula fractured following a hit-and-run. X-rays showed that there was a transverse fracture of the upper end of the fibula. It was manifested clinically by inability to flex his foot at the ankle joint plus weak extension of the phalanges. What nerve is suspected to be injured in such a case?
Your Answer: Superficial peroneal
Correct Answer: Deep peroneal
Explanation:The deep peroneal nerve supplies the muscles allowing for flexion of the foot at the ankle joint, namely the tibialis anterior and peroneus tertius muscles. The peroneus tertius, peroneus brevis, and peroneus longus evert the foot, whereas the tibialis anterior and tibialis posterior invert the foot. Fibres of the deep peroneal nerve originate from L4, L5, and S1.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 63
Correct
-
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: 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 64
Correct
-
During a laparoscopic inguinal hernia repair, the surgeon finds an artery in the extraperitoneal connective tissue (preperitoneal fat) that courses vertically and just medial to the bowel as the bowel passes through the abdominal wall. Which artery is this?
Your Answer: Inferior epigastric
Explanation:The inferior epigastric artery comes from the external iliac artery just above the inguinal ligament to curve forward in the subperitoneal tissue and then ascend obliquely along the medial margin of the deep inguinal ring. It continues to ascend between the rectus abdominis and the posterior lamella of its sheath after piercing the fascia transversalis and passing anterior to the linea semicircularis. Finally it gives off numerous branches that anastomose above the umbilicus with the superior epigastric branch of the internal mammary artery and with the lower intercostal arteries. As this artery ascends obliquely upwards from its origin it lies along the lower medial margins of the deep inguinal ring and posterior to the start of the spermatic cord. It is found in the preperitoneal fat of the abdomen lying just superficial to the peritoneum and forms the lateral umbilical fold. Hernias that pass lateral to this are indirect and medial to this, direct hernias.
The deep circumflex artery travels along the iliac crest on the inner surface of the abdominal wall. It is very lateral to the abdominal wall and hernias would pass medial to it.
The superficial circumflex iliac, superficial epigastric, superficial external pudendal arteries are all superficial arteries found in the superficial fascia.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 65
Correct
-
Which of the following variables are needed to calculate inspiratory reserve volume of a patient?
Your Answer: Tidal volume, vital capacity and expiratory reserve volume
Explanation:Vital capacity = inspiratory reserve volume + tidal volume + expiratory reserve volume. Thus, inspiratory reserve volume can be calculated if tidal volume, vital capacity and expiratory reserve volume are known.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 66
Incorrect
-
The specimen sent to the pathologist for examination was found to be benign. Which one of the following is most likely a benign tumour?
Your Answer: Haematoma
Correct Answer: Warthin’s tumour
Explanation:Warthin’s tumour is also known as papillary cystadenoma lymphomatosum. It is a benign cystic tumour of the salivary glands containing abundant lymphocytes and germinal centres. It has a slightly higher incidence in males and most likely occur in older adults aged between 60 to 70 years. This tumour is also associated with smoking. Smokers have an eight-fold greater risk in developing the tumour compared to non-smokers.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 67
Correct
-
A cell is classified on the basis of its regenerative ability. Which of the following cells represent a permanent cell?
Your Answer: Erythrocyte
Explanation:An erythrocyte is the last cell in the progeny of RBC cell division and is not capable of further division and regeneration. Hepatocytes, osteocytes and epithelium of kidney tubules are all stable cells. Colonic mucosa and pluripotent hematopoietic stem cells are all labile cells.
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This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
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Question 68
Correct
-
A 15-day old baby was brought to the emergency department with constipation for 4 days. On examination, the abdomen of the baby was found to be distended and tender all over. No bowel sounds were heard. A sigmoid colon biopsy was carried out, which showed absent ganglion cells. What is the diagnosis?
Your Answer: Hirschsprung’s disease
Explanation:Hirschsprung’s disease is characterized by congenital absence of the autonomic plexus (Meissner’s and Auerbach’s plexus) in the intestinal wall. Usually limited to the distal colon, it can occasionally involve the entire colon or even the small bowel. There is abnormal or absent peristalsis in the affected segment, resulting in continuous spasm of smooth muscle and partial/complete obstruction. This causes accumulation of intestinal contents and dilatation of proximal segment. Skip lesions are highly uncommon. This disease is seen early in life with 15% patients presenting in first month, 60% by 1 year of age and 85% by the age of 4 years. Symptoms include severe and complete constipation, abdominal distension and vomiting. Patients with involvement of ultra-short segments might have mild constipation with intervening diarrhoea. In older children, symptoms include failure to thrive, anorexia, and lack of an urge to defecate. On examination, an empty rectum is revealed with stool palpable high up in the colon. If not diagnosed in time, it can lead to Hirschsprung’s enterocolitis (toxic megacolon), which can be fulminant and lead to death. Diagnosis involves a barium enema or a rectal suction biopsy. Barium enema shows a transition in diameter between the dilated, normal colon proximal to the narrowed, affected distal segment. It is to be noted that barium enema should be done without prior preparation, which can dilate the abnormal segment, leading to a false-negative result. A 24-hour post-evacuation film can be obtained in the neonatal period – if the colon is still filled with barium, there is a high likelihood of Hirschsprung’s disease. Full-thickness rectal biopsy is diagnostic by showing the absence of ganglion cells. Acetylcholinesterase staining can be done to highlight the enlarged nerve trunks. Abnormal innervation can also be demonstrated by rectal manometry.
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This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
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Question 69
Correct
-
A new-born was found to have an undeveloped spiral septum in the heart. This is characteristic of which of the following?
Your Answer: Persistent truncus arteriosus
Explanation:Persistent truncus arteriosus is a congenital heart disease that occurs when the primitive truncus does not divide into the pulmonary artery and aorta, resulting in a single arterial trunk. The spiral septum is created by fusion of a truncal septum and the aorticopulmonary spiral septum. Incomplete development of these septa results in incomplete separation of the common tube of the truncus arteriosus and the aorticopulmonary trunk.
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This question is part of the following fields:
- Cardiovascular
- Pathology
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Question 70
Correct
-
A man was stabbed in the thigh following a bar brawl. A superficial vein was injured which terminates in the femoral vein. This superficial vein is?
Your Answer: Great saphenous
Explanation:The great saphenous vein is considered the longest vein in the body. It terminates in the femoral vein nearly 3cm below the inguinal ligament. It begins at the dorsum of the foot in the medial marginal vein and ascends at the medial side of the leg in relation with the saphenous nerve.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 71
Correct
-
Which of the following bones was most likely fractured following an injury in the medial side of the foot between the navicular behind and base of the first metatarsal in front?
Your Answer: First cuneiform
Explanation:The first cuneiform bone is the largest of the three cuneiforms. It is situated at the medial side of the foot, between the navicular behind and the base of the first metatarsal in front.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 72
Correct
-
Post-total gastrectomy, there will be a decreased production of which of the following enzymes?
Your Answer: Pepsin
Explanation:Pepsin is a protease that is released from the gastric chief cells and acts to degrade proteins into peptides. Released as pepsinogen, it is activated by hydrochloric acid and into pepsin itself. Gastrin and the vagus nerve trigger the release of pepsinogen and HCl when a meal is ingested. Pepsin functions optimally in an acidic environment, especially at a pH of 2.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 73
Correct
-
A 65 year old man with a history of diabetes and hypertension presented with a stroke a few months ago severely affecting his speech and movement in the right arm and leg. A cerebral angiogram revealed a middle cerebral artery occlusion. A recent CT scan was done which revealed a 5 cm cystic space in his left parietal lobe. This lesion is a result of which of the following forms of resolution?
Your Answer: Liquefactive necrosis
Explanation:Characteristically, the brain will undergo liquefactive necrosis following ischaemic injury. This leaves a cystic space in that region which would show up on a CT scan. Atrophy would result in a generalized decrease in the brain size. Coagulative necrosis typically occurs in parenchymal organs e.g. the spleen or kidney which have a lower lipid content. Caseous necrosis is typical in granulomatous tuberculosis infection. Apoptosis will not form a cystic area as it is programmed cell death involving a individual cells. Gangrenous necrosis is characteristic of ischaemic injury of the lower limb and GI tract. Fibrinous necrosis results from necrotic damage to the blood vessels with the leaking of proteins into the vessel, appearing bright pink on H & E staining.
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This question is part of the following fields:
- Cell Injury & Wound Healing; Neurology
- Pathology
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Question 74
Correct
-
Which of the following diseases is caused by intra-articular and/or extra-articular deposition of calcium pyrophosphate dihydrate (CPPD) crystals, due to unknown causes?
Your Answer: Pseudogout
Explanation:Pseudogout or chondrocalcinosis is a rheumatological disease caused by the accumulation of crystals of calcium pyrophosphate dihydrate (CPPD) in the connective tissues. It is frequently associated with other conditions, such as trauma, amyloidosis, gout, hyperparathyroidism and old age, which suggests that it is secondary to degenerative or metabolic changes in the tissues. The knee is the most commonly affected joint. It causes symptoms similar to those of rheumatoid arthritis or osteoarthritis.
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This question is part of the following fields:
- Orthopaedics
- Pathology
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Question 75
Correct
-
The primary motor cortex is located in the:
Your Answer: Precentral gyrus
Explanation:The primary motor cortex is located in the dorsal part of the precentral gyrus and the anterior bank of the central sulcus. The precentral gyrus lies anterior to the postcentral gyrus and is separated from it by a central sulcus. Its anterior border is the precentral sulcus, while inferiorly it borders to the lateral fissure (Sylvian fissure).
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This question is part of the following fields:
- Neurology
- Physiology
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Question 76
Correct
-
Which of the following will increase blood pressure and cause hypokalaemia?
Your Answer: Angiotensin II
Explanation:Angiotensin is a peptide that is released in response to a decrease in blood volume and blood pressure. It has multiple functions but mainly acts to cause vasoconstriction, increase BP and release aldosterone from the adrenal cortex. It is a powerful vasoconstrictor and release of aldosterone causes increased retention of sodium and excretion of potassium.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 77
Correct
-
Following an accident, a man was unable to extend the wrist and metacarpophalangeal joints, despite sensation being intact. Which nerve was likely damaged?
Your Answer: Posterior interosseous nerve
Explanation:The posterior interosseous nerve which causes, what is known as the posterior interosseous nerve syndrome. The nerve is compressed before it bifurcates to form the medial and lateral branches. The compression is beyond the origin of the branches to the radial wrist extensors and the radial sensory nerve. The result of such a case is paralysis of the digital extensors and the extensor carpi ulnaris, resulting in dorsoradial deviation of the wrist.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 78
Correct
-
The pleural cavity is the space between the two pulmonary pleurae which cover the lungs. What is the normal amount of pleural fluid?
Your Answer: 10 ml
Explanation:Pleural fluid is a serous fluid produced by the serous membrane covering normal pleurae. Most fluid is produced by the parietal circulation (intercostal arteries) via bulk flow and reabsorbed by the lymphatic system. The total volume of fluid present in the intrapleural space is estimated to be only 2–10 ml. A small amount of protein is present in intrapleural fluid. Normally, the rate of reabsorption increases as a physiological response to accumulating fluid.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 79
Correct
-
13 year old girl developed sun burnt cheeks after spending the day playing on the beach. What is the underlying mechanism to her injury?
Your Answer: Free radical injury
Explanation:Free radicals are a by-product of chemical reactions with an unpaired electron in their outer most shell. They are capable of causing wide spread damage to cells. They can cause autolytic reactions thereby converting the reactants into free radicals. By absorbing sun light, the energy is used to hydrolyse water into hydroxyl (OH) and hydrogen (H) free radicals which can cause injury by lipid peroxidation of membranes, oxidative modification of proteins and damage to the DNA structure.
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This question is part of the following fields:
- Cell Injury & Wound Healing; Dermatology
- Pathology
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Question 80
Correct
-
Which of the following muscles attach to the hyoid bone?
Your Answer: Middle pharyngeal constrictor
Explanation:The hyoid bone is a horseshoe-shaped bone situated in the anterior midline of the neck between the chin and the thyroid cartilage. A large number of muscles attach to the hyoid: Superiorly – the middle pharyngeal constrictor muscle, hyoglossus muscle, genioglossus, intrinsic muscles of the tongue and suprahyoid muscles. Inferiorly – the thyrohyoid muscle, omohyoid muscle and sternohyoid muscle.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 81
Incorrect
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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: 550 mmol/day
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 82
Incorrect
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A 39-year-old man, after radiological evaluation and thoracentesis, was found to have chylothorax. What is the most probable cause of this diagnose?
Your Answer: Tuberculosis
Correct Answer: Mediastinal malignant lymphoma
Explanation:Chylothorax is a potentially lethal condition characterized by fluid (chyle) accumulation in the pleural cavity, resulting from disruption of lymphatic drainage in the thoracic duct. Chyle is a fluid rich in triglycerides and chylomicrons and can originate from the thorax, the abdomen or both. Malignant tumours, especially lymphoma, are the most common causes of nontraumatic chylothorax. Bronchogenic carcinoma and trauma are the most common causes after lymphomas. Other rare causes of chylothorax are; granulomatous diseases, tuberculosis, congenital malformations, nephrotic syndrome, hypothyroidism, cirrhosis, decompensated heart failure and idiopathic chylothorax.
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This question is part of the following fields:
- Pathology
- Respiratory
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Question 83
Correct
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A 55 year old man presented with a 4 day history of cough and fever. His sputum culture showed the presence of Strep pneumoniae. Which of the following substances produced by the inflammatory cells will result in effective clearance of this organism from the lung parenchyma?
Your Answer: Hydrogen peroxide
Explanation:Hydrogen peroxide is produced by myeloperoxidase to form a potent oxidant that eliminates bacteria, but is not effective in chronic granulomatous diseases.
Platelet activating factor will lead to the activation, adhesion and aggregation of platelets but will not directly kill bacteria.
Prostaglandins cause vasodilation but do not activate neutrophils.
Kallikrein promotes formation of bradykinin that leads to vasodilation.
Leukreines increase vascular permeability.
Cytokines are communicating molecules between immune cells but directly will not kill bacteria.
Interleukins will regulate the immune response.
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This question is part of the following fields:
- Inflammation & Immunology; Respiratory
- Pathology
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Question 84
Incorrect
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Carbachol is a cholinergic agonist. In which of these cases should carbachol be administered?
Your Answer: Congestive heart failure
Correct Answer: Cataract surgery
Explanation:Carbachol (carbamylcholine) is a cholinergic agent, a choline ester and a positively charged quaternary ammonium compound. It is primarily used for various ophthalmic purposes, such as for treating glaucoma, or for use during ophthalmic surgery. It is usually administered topically to the eye or through intraocular injection. It is not well absorbed in the gastro-intestinal tract and does not cross the blood–brain barrier.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 85
Correct
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Action potentials are used extensively by the nervous system to communicate between neurones and muscles or glands. What happens during the activation of a nerve cell membrane?
Your Answer: Sodium ions flow inward
Explanation:During the generation of an action potential, the membrane gets depolarized which cause the voltage gated sodium channels to open and sodium diffuses inside the neuron, resulting in the membrane potential moving towards a positive value. This positive potential will then open the voltage gated potassium channels and cause more K+ to move out decreasing the membrane potential and restoring the membrane potential to its resting value.
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This question is part of the following fields:
- General
- Physiology
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Question 86
Incorrect
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The muscle that stabilizes the stapes is innervated by which of the following nerves?
Your Answer: Vagus nerve
Correct Answer: Facial nerve
Explanation:The stapedius is the smallest skeletal muscle in the human body. At just over one millimetre in length, its purpose is to stabilize the smallest bone in the body, the stapes and is innervated by a branch of the facial nerve.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 87
Correct
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A 7-year-old boys undergoes a testicular biopsy after a tumour is found in his right testis. Elements similar to hair and teeth are found in it. What kind of tumour is this?
Your Answer: Teratoma
Explanation:A teratoma is a tumour containing tissue elements that are similar to normal derivatives of more than one germ layer. They usually contain skin, hair, teeth and bone tissue and are more common in children, behaving as a benign tumour. After puberty, they are regarded as malignant and can metastasise.
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This question is part of the following fields:
- Pathology
- Urology
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Question 88
Incorrect
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A 62-year-old woman presented to the doctor complaining of spine pain, fatigue and oliguria. She is diagnosed with chronic renal failure. Dipstick testing shows no protein, glucose, nitrite or ketones but a semi-quantitative sulphosalicylic acid test for urine protein is positive. Which of the following is the most probable cause of chronic renal failure in this patient.
Your Answer: Systemic lupus erythematosus
Correct Answer: Multiple myeloma
Explanation:Dipstick results are negative because the proteins found in the urine of this patient are not albumin but Bence Jones proteins. A Bence Jones protein is a monoclonal globulin protein commonly detected in patients affected by multiple myeloma. Multiple myeloma is a malignancy of plasma cells characterised by the production of monoclonal immunoglobulin. Symptoms include bone pain, bone fractures, bleeding, neurologic symptoms, fatigue, frequent infections and weight loss.
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This question is part of the following fields:
- Pathology
- Renal
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Question 89
Correct
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A surgical registrar performing an adrenalectomy procedure on the left suprarenal gland of a 25 - year old male patient, accidentally jabbed and injured a vital structure that lies anterior to the left suprarenal organ. Which of the following was the structure most likely injured?
Your Answer: Pancreas
Explanation:The adrenal (suprarenal) glands are organs of the endocrine system located on top of each of the kidneys. The left suprarenal gland, in question, is crescent in shape and slightly larger than the right suprarenal gland. It is posteriorly located to the lateral aspect of the head of the pancreas which is thus the most likely to be injured. The other organs like the duodenum, liver and the inferior vena cava are related to the right suprarenal gland. The spleen and the colon are not in close proximity with the left suprarenal gland and are not likely to be the organs injured.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 90
Incorrect
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A 27-year-old HIV patient started on an antifungal agent. Which antifungal agent that inhibits the biosynthesis of fungal ergosterol was given to the patient?
Your Answer: Nystatin
Correct Answer: Ketoconazole
Explanation:Ketoconazole is a synthetic imidazole antifungal drug used primarily to treat fungal infections. It inhibits the biosynthesis of ergosterol by blocking demethylation at the C14 site of the ergosterol precursor. Amphotericin B and Nystatin impair permeability of the cell membrane. Flucytosine interferes with DNA synthesis, while the target of griseofulvin is the microtubules
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 91
Incorrect
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A 40-year old woman with portal hypertension has impaired venous drainage of the anal canal above the pectinate line. Thus, there might be an increase in blood flow downward to the systemic venous system via anastomoses with the inferior rectal vein. This is a tributary of?
Your Answer: Internal iliac vein
Correct Answer: Internal pudendal vein
Explanation:The inferior rectal vein drains into the internal pudendal vein. In addition the external iliac vein is one of the two branches of the common iliac vein however the internal iliac vein and it’s tributaries (including the pudendal vein) are much more important in draining the pelvic structures.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 92
Correct
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Which of the following is responsible for the maximum increase in total peripheral resistance on sympathetic stimulation?
Your Answer: Arterioles
Explanation:Arterioles are also known as the resistance vessels as they are responsible for approximately half the resistance of the entire systemic circulation. They are richly innervated by the autonomic nervous system and hence, will bring about the maximum increase in peripheral resistance on sympathetic stimulation.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 93
Correct
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A 20 year lady is brought to the A&E following a road accident. She is hypotensive and a CT scan of the abdomen reveals a shattered spleen. An emergency splenectomy is performed where the splenic artery is ligated right at its origin. Which of the following arteries will have a diminished blood flow owing to ligation of the splenic artery at its origin?
Your Answer: Left gastroepiploic
Explanation:Ligation of the splenic artery right at its point of origin should cut off blood flow in its branches. The following are the branches of the splenic artery: pancreatic branches, short gastric branches and left gastroepiploic arteries.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 94
Correct
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A 70-year old man who is suspected to have a perforated colonic diverticulum is explored in theatre through a midline incision. This incision will be through the:
Your Answer: Linea alba
Explanation:The linea alba is the point where this incision was made. It is a tendinous raphe in the midline of the abdomen extending between the xiphoid process and the symphysis pubis. It is placed between the medial borders of the recti and is formed by the blending of the aponeuroses of the external and internal obliques and transversi.
The linea aspera is a vertical ridge on the posterior surface of the femur.
The arcuate line is the inferior border of the posterior rectus sheath behind the rectus abdominis muscle.
The semilunar line is the lateral margin of the rectus abdominis.
The iliopectineal line is a line on the pelvic bones formed by the arcuate line of the ilium and the pectineal line of the pubis.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 95
Correct
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Chronic obstructive pulmonary disease (COPD) is likely to result in:
Your Answer: Respiratory acidosis
Explanation:COPD leads to respiratory acidosis (chronic). This occurs due to hypoventilation which involves multiple causes, such as poor responsiveness to hypoxia and hypercapnia, increased ventilation/perfusion mismatch leading to increased dead space ventilation and decreased diaphragm function.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 96
Incorrect
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A medical student is asked to calculate the net pressure difference in a capillary wall, considering: Interstitial fluid hydrostatic pressure = –3 mmHg, Plasma colloid osmotic pressure = 28 mmHg, Capillary hydrostatic pressure = 17 mmHg, Interstitial fluid colloid osmotic pressure = 8 mmHg, and Filtration coefficient = 1. Which is the correct answer?
Your Answer: +3 mmHg
Correct Answer: 0 mmHg
Explanation:The rate of filtration at any point along a capillary depends on a balance of forces sometimes called Starling’s forces after the physiologist who first described their operation in detail. The Starling principle of fluid exchange is key to understanding how plasma fluid (solvent) within the bloodstream (intravascular fluid) moves to the space outside the bloodstream (extravascular space). Fluid movement = k[(pc– pi)–(Πc– Πi)] where k = capillary filtration coefficient, pc = capillary hydrostatic pressure, pi= interstitial hydrostatic pressure, Πc = capillary colloid osmotic pressure, Πi = interstitial colloid osmotic pressure. Therefore: 1 × [capillary hydrostatic pressure (17) – interstitial fluid hydrostatic pressure (–3)] – [plasma colloid osmotic pressure (28) – interstitial fluid colloid osmotic pressure (8)] = 0 mmHg
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 97
Correct
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A 51-year old woman after undergoing a barium swallowing was discovered to be suffering from an oesophageal hiatal hernia. Which muscle fibres of the diaphragm border this hernia directly if the stomach herniates through an enlarged oesophageal hiatus?
Your Answer: Right crus
Explanation:The oesophageal hiatus is a natural fissure on the thoracic diaphragm that allows passage of the oesophagus and the vagal nerve. The oesophageal hiatus is located in one of the tendinous structures of the diaphragm that connect it to the spine which is known as the right crus. In case of an hiatal hernia, this diaphragmatic structure would be the one bordering the hernia as it is the structure that encircles the oesophageal hiatus.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 98
Correct
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A 55-year old lady underwent a major surgery for repair of an aortic aneurysm. Her blood pressure was low throughout the intra-operative and the post-operative period, along with increasing serum creatinine and urea. Microscopic examination of her urine showed multiple granular and hyaline casts. What is the likely condition the patient is suffering from?
Your Answer: Acute tubular necrosis
Explanation:The most common predisposing factor leading to acute tubular necrosis is ischemia, typically seen in hospitalized patients with low blood pressure.
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This question is part of the following fields:
- Pathology
- Renal
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Question 99
Correct
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Cervical intraepithelial neoplasia on Pap smear of a 34-year old lady is most likely associated with which of the following?
Your Answer: Human papillomavirus infection
Explanation:CIN (Cervical intraepithelial neoplasia) is considered a precursor of cervical cancer and is likely caused due to infection with human papillomavirus (HPV) types 16, 18, 31, 33, 35 or 39. The risk factors for cervical cancer include multiple sex partners, young age at the time of first intercourse, intercourse with men whose previous partners had cervical cancer. Also, smoking and immunodeficient states are considered contributory. CIN is graded as mild (grade I), moderate (grade II) and severe dysplasia or carcinoma in situ (grade III). CIN III rarely regresses spontaneously and can lead to invasive carcinoma by invading the basement membrane. Squamous cell carcinomas are the commonest cervical cancer seen in 80-85% of all cases. Others are commonly adenocarcinomas. Cervical cancer can spread by direct extension, lymphatic spread to pelvic and para-aortic nodes or by hematogenous route.
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This question is part of the following fields:
- Pathology
- Women's Health
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Question 100
Incorrect
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A 50-year-old gentleman was recently diagnosed with hypertension, with no other abnormalities on physical examination. Further investigations revealed the following :
Na+ 144 mmol/l
K+ 3.0 mmol/l
Cl- 107 mmol/l
Bicarbonate 25 mmol/l.
Blood glucose 5.8 mmol/l.
What is the likely diagnosis?Your Answer: Cushing syndrome
Correct Answer: Conn syndrome
Explanation:Overproduction of aldosterone (a mineralocorticoid) by the adrenal glands is known as Conn’s syndrome. It can be either due to an aldosterone-secreting adrenal adenoma (50-60% cases) or adrenal gland hyperplasia (40-50% cases). Excess aldosterone leads to sodium and water retention, along with potassium excretion. This leads to arterial (non-essential) hypertension. Conn’s syndrome is the commonest cause of primary hyperaldosteronism. Other symptoms include muscle cramps, headache (due to hypokalaemia) and metabolic alkalosis, which occurs due to increased secretion of H+ ions by the kidney. The raised pH of the blood traps calcium leading to symptoms of hypocalcaemia, which can be mimicked by liquorice ingestion and Liddle syndrome. To diagnose Conn’s syndrome, the ratio of renin and aldosterone is measured. Due to suppression of renin secretion, there is low renin to aldosterone ratio (<0.05). However, anti-hypertensives may affect the test results and should be withdrawn for 6 weeks. Computed tomography can also be done to detect the presence of adrenal adenoma. Cushing’s syndrome does not cause hypokalaemia with normal serum glucose levels. Nelson’s syndrome refers to increased ACTH secretion due to pituitary adenoma. Pheochromocytoma will not lead to hypokalaemia even though hypertension can be seen.
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This question is part of the following fields:
- Endocrine
- Pathology
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SESSION STATS - PERFORMANCE PER SPECIALTY
