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Question 1
Correct
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A 65-year-old man complains of headaches, weakness, cramps, and confusion; blood tests reveal he has severe hyponatremia. The most likely cause is:
Your Answer: Severe diarrhoea or vomiting
Explanation:Hyponatraemia occurs when the sodium level in the plasma falls below 135 mmol/l. Hyponatraemia is an abnormality that can occur in isolation or, more commonly as a complication of other medical illnesses. Severe hyponatraemia may cause osmotic shift of water from the plasma into the brain cells. Typical symptoms include nausea, vomiting, headache and malaise. As the hyponatraemia worsens, confusion, diminished reflexes, convulsions, stupor or coma may occur. The cause of hyponatremia is typically classified by a person’s fluid status into low volume, normal volume, and high volume. Low volume hyponatremia can occur from diarrhoea, vomiting, diuretics, and sweating.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 2
Correct
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The parasympathetic fibres of the oculomotor nerve was impinged due to a growing tumour. The function of which of the following structures will be affected?
Your Answer: Ciliary muscle
Explanation:The oculomotor nerve is the third cranial nerve (CNIII). It offers motor and parasympathetic innervation to many of the ocular structures. The motor fibres innervate a number of the extraocular muscles. While the parasympathetic fibres supply the sphincter pupillae and the ciliary muscles of the eye, and the sympathetic fibres innervates the superior tarsal muscles.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 3
Correct
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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 4
Correct
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In a study, breast lumps were analysed to determine the characteristic of malignant neoplasm on biopsy. What microscopic findings are suggestive of malignancy?
Your Answer: Invasion
Explanation:Invasion is suggestive of malignancy and an even better option would have been metastasis. Pleomorphism is found in both benign and malignant neoplasms along with atypia and anaplasia. A height nuclear/cytoplasmic ratio is suggestive of malignancy but not the best indicator. Malignant tumours are aggressive and growth rapidly. Necrosis can be seen in benign tumours if they deplete their blood supply.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 5
Correct
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Skeletal muscle fibres are divided into two basic types, type I (slow-twitch fibres) and type II (fast-twitch fibres). Fast muscle fibres do which of the following:
Your Answer: Use anaerobic metabolism
Explanation:Skeletal muscles are divided into two types:
1) type I also known as the slow twitch fibres. They use oxygen for their metabolism and as a result they have a high endurance potential. To support this they have abundant mitochondria and myoglobin, so they appear red/dark.
2) type II fibres also called fast twitch fibres, are low endurance fibres used during anaerobic metabolism. They are required for short bursts of strength and cannot sustain contractions for long periods of time.
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This question is part of the following fields:
- General
- Physiology
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Question 6
Correct
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A 55 year-old construction worker is diagnosed with malignant mesothelioma. Exposure to which substance increased his risk in developing mesothelioma?
Your Answer: Asbestos
Explanation:Mesothelioma is a rare, aggressive form of cancer that develops in the lining of the lungs, abdomen or heart. It is linked to inhalation of asbestos commonly used in ship building and the insulation industry. It has no known cure and has a very poor prognosis.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 7
Correct
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Which of the following diseases affects young adults, causing pain in any bone -particularly long bones- which worsens at night, and is typically relieved by common analgesics, such as aspirin?
Your Answer: Osteoid osteoma
Explanation:Osteoid osteoma, which tends to affect young adults, can occur in any bone but is most common in long bones. It can cause pain (usually worse at night) that is typically relieved by mild analgesics, such as non-steroidal anti-inflammatory drugs. X-ray findings include a small radiolucent zone surrounded by a larger sclerotic zone.
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This question is part of the following fields:
- Orthopaedics
- Pathology
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Question 8
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 9
Correct
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A 34-year old gentleman presented with acute pancreatitis to the emergency department. On enquiry, there was found to be a history of recurrent pancreatitis, eruptive xanthomas and raised plasma triglyceride levels associated with chylomicrons. Which of the following will be found deficient in this patient?
Your Answer: Lipoprotein lipase
Explanation:The clinical features mentioned here suggest the diagnosis of hypertriglyceridemia due to lipoprotein lipase (LPL) deficiency. LPL aids in hydrolysing the lipids in lipoproteins into free fatty acids and glycerol. Apo-CII acts as a co-factor. Deficiency of this enzyme leads to hypertriglyceridemia.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 10
Correct
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The rotator cuff surrounds the shoulder joint and consists of the supraspinatus, infraspinatus, subscapularis and which one other muscle?
Your Answer: Teres minor
Explanation:The correct answer is the teres minor muscle. These group of muscles play an important role in protecting the shoulder joint and keeping the head of the humerus in the glenoid fossa of the scapula. This fossa is somehow shallow and needs support to allow for the full mobility that the shoulder joint has.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 11
Correct
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Different substances have different renal clearance rates. Which of the following substances should have the lowest renal clearance rate in a healthy patient?
Your Answer: Glucose
Explanation:Under normal conditions the renal clearance of glucose is zero, since glucose is completely reabsorbed in the renal tubules and not excreted. Glycosuria – the excretion of glucose into the urine- is nearly always caused by elevated blood glucose levels, most commonly due to untreated diabetes mellitus.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 12
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: External 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 13
Correct
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Low molecular weight heparin (LMWH) has less side effects than heparin and is used in the prophylaxis and treatment of venous and arterial thrombotic disorders. Which of the following is LMWHs mechanism of action?
Your Answer: Inhibition of factor Xa
Explanation:Low molecular weight heparin (LMWH) is a anticoagulant that differs from normal heparin in that it has only short chains of polysaccharide. LMWH inhibits thrombin formation by converting antithrombin from a slow to a rapid inactivator of coagulation factor Xa.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 14
Correct
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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 15
Incorrect
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What is the normal duration of the ST segment?
Your Answer: 0.4 s
Correct Answer: 0.08 s
Explanation:The ST segment lies between the QRS complex and the T-wave. The normal duration of the ST segment is 0.08 s. ST-segment elevation or depression may indicate myocardial ischaemia or infarction.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 16
Incorrect
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A 45 year old lady has been diagnosed with Friedreich's ataxia that has affected her medial group of nuclei in the anterior horn of the spinal cord. Which of the following structures will have their muscles affected?
Your Answer: Leg
Correct Answer: Axial muscles
Explanation:The cells in the anterior horn can be arranged in the following three main groups: medial, lateral and central. The medial group of nuclei in the anterior horn of the spinal cord are located along the entire length of the spinal cord and are responsible for the innervation of the axial muscles of the body ( muscles of the head and neck region). Thus this disease will most likely affect the functioning of the muscles of the head and neck.
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This question is part of the following fields:
- Anatomy
- Neurology
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Question 17
Correct
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Enlargement of the spleen as seen in Gaucher's disease pushes the spleen downward and medially. What structure limits the straight-vertical-downward movement?
Your Answer: Left colic flexure
Explanation:The left colic flexure (also known as the splenic flexure), is the point where the colon takes a sharp turn downwards. It is the point where the transverse colon ends and the descending colon begins. It is located immediately inferior to the spleen so an enlarged spleen must move medially to avoid this colic flexure.
The left suprarenal gland is retroperitoneal.
The Ligament of Treitz suspends the fourth part of the duodenum from the posterior abdominal wall.
The stomach, pancreas and liver lie medial to the spleen and thus would not prevent a vertical downward movement.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 18
Incorrect
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A surgeon performing a Whipple's procedure, that involves mobilizing the head of the pancreases, accidentally injured a structure immediately posterior to the neck of the pancrease which bled out. Which structure is most likely to have been injured?
Your Answer: Portal vein
Correct Answer: Superior mesenteric artery
Explanation:The structure immediately posterior to the neck of the pancreas is the superior mesenteric vein. The neck of the pancreas lies anterior to the superior mesenteric vein, which joins with the splenic vein to form the portal vein.
The superior mesenteric artery (SMA) is also located in proximity to the neck of the pancreas. Specifically, the SMA emerges from the abdominal aorta just below the level of the pancreas and passes posterior to the neck of the pancreas before it descends into the mesentery to supply the intestines. Thus, both the superior mesenteric vein and the superior mesenteric artery are key vascular structures related to the posterior aspect of the neck of the pancreas.
Bleeding out would suggest an arterial injury.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 19
Correct
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Which of the following coagulation factors cross-links fibrin?
Your Answer: Factor XIII
Explanation:Factor XIII, also known as fibrin stabilizing factor, is an enzyme of the coagulation cascade that crosslinks fibrin. Deficiency of FXIII may cause bleeding tendency but paradoxically, it may also predispose to thrombosis.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 20
Incorrect
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Which of the following muscles is solely contained in the anterior triangle of the neck and divides the anterior triangle into three smaller triangles?
Your Answer: Omohyoid
Correct Answer: Digastric
Explanation:The digastric muscle is a small muscle located under the jaw. It lies below the body of the mandible, and extends, in a curved form, from the mastoid process to the symphysis menti. The digastric divides the anterior triangle of the neck into three smaller triangles:
– The submaxillary triangle, bounded above by the lower border of the body of the mandible and a line drawn from its angle to the sternocleidomastoid, below by the posterior belly of the digastric and the stylohyoid and in front by the anterior belly of the digastric
– The carotid triangle, bounded above by the posterior belly of the digastric and stylohyoid, behind by the sternocleidomastoid and below by the omohyoid
– The suprahyoid or submental triangle, bounded laterally by the anterior belly of the digastric, medially by the midline of the neck from the hyoid bone to the symphysis menti and inferiorly by the body of the hyoid bone.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 21
Correct
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Acute respiratory distress syndrome (ARDS) is a medical condition that occurs in critically ill patients, and can be triggered by events such as trauma and sepsis. Which of the following variables is most likely to be lower than normal in a patient with ARDS?
Your Answer: Lung compliance
Explanation:Acute (or Adult) respiratory distress syndrome (ARDS) is a medical condition occurring in critically ill patients characterized by widespread inflammation in the lungs. The development of acute respiratory distress syndrome (ARDS) starts with damage to the alveolar epithelium and vascular endothelium, resulting in increased permeability to plasma and inflammatory cells. These cells pass into the interstitium and alveolar space, resulting in pulmonary oedema. Damage to the surfactant-producing type II cells and the presence of protein-rich fluid in the alveolar space disrupt the production and function of pulmonary surfactant, leading to micro atelectasis and impaired gas exchange. The pathophysiological consequences of lung oedema in ARDS include a decrease in lung volumes, compliance and large intrapulmonary shunts. ARDS may be seen in the setting of pneumonia, sepsis, following trauma, multiple blood transfusions, severe burns, severe pancreatitis, near-drowning, drug reactions, or inhalation injuries.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 22
Incorrect
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A 14 year old girl suffers from haemophilia A and chronic knee pain with progressive swelling and deformity over the last 4 years. Test results reveal a significantly reduced factor VIII activity. Which of the following is seen in the knee joint space after an acute painful episode?
Your Answer: Charcot Leyden crystals
Correct Answer: Cholesterol crystals
Explanation:Due to breakdown of the red blood cell membrane in haemophilic patients, cholesterol crystals are formed by the lipids. On the other hand lipofuscin deposition does not occur in haemolysis or haemorrhage. Neutrophil accumulation suggests acute inflammation. Anthracotic pigment is an exogenous carbon pigment that deposits in the lung from dust. Russell bodies are intracellular accumulations of immunoglobins in plasma cells. Curschmann’s spirals and Charcot Leyden crystals are pathognomonic of asthma.
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This question is part of the following fields:
- Cell Injury & Wound Healing; Haematology
- Pathology
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Question 23
Correct
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Which of these nerves controls adduction of hand?
Your Answer: Ulnar nerve
Explanation:The adductors of the fingers are the palmer interossei. They are supplied by the ulnar nerve, which is a branch of the medical cord of the brachial plexus.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 24
Correct
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Arterial blood gas analysis of a man admitted with acute exacerbation of chronic obstructive pulmonary disease (COPD) showed the following: pH = 7.28, p(CO2) = 65.5 mmHg, p(O2)= 60 mmHg and standard bicarbonate = 30.5 mmol/l. This patient had:
Your Answer: Respiratory acidosis
Explanation:Acidosis with high p(CO2) and normal standard bicarbonate indicates respiratory acidosis, commonly seen in acute worsening of COPD patients. Respiratory acidosis occurs due to alveolar hypoventilation which leads to increased arterial carbon dioxide concentration (p(CO2)). This in turn decreases the HCO3 –/p(CO2) and decreases pH. In acute respiratory acidosis, the p(CO2) is raised above the upper limit of normal (over 45 mm Hg) with a low pH. However, in chronic cases, the raised p(CO2) is accompanied with a normal or near-normal pH due to renal compensation and an increased serum bicarbonate (HCO3 – > 30 mmHg).
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 25
Correct
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A terrorist running away from the police was shot in the back. The bullet hit his left lung halfway between its apex and the diaphragmatic surface. Which part of the lung was most likely to be injured?
Your Answer: Inferior lobe
Explanation:The oblique fissure of the left lung is so sharp that the posterior surface of the left lung is mostly composed of the inferior lobe so that the point halfway between the apex and the diaphragmatic surface of the lung would result in injury to the inferior lobe.
The hilum is the point on the medial surface of the lung where the structures that form the root of the lung enter and leave the lung.
The lingual on the other hand is part of the superior lobe of the left lung and it is part of the anterior and superior sides of the lung.
The middle lobe is only found on the right lung.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 26
Correct
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The Henderson–Hasselbalch equation describes the derivation of pH as a measure of acidity. According to this equation, the buffering capacity of the system is at maximum when the number of free anions compared with undissociated acid is:
Your Answer: Equal
Explanation:In 1908, Lawrence Joseph Henderson wrote an equation describing the use of carbonic acid as a buffer solution. Later, Karl Albert Hasselbalch re-expressed that formula in logarithmic terms, resulting in the Henderson–Hasselbalch equation. The equation is also useful for estimating the pH of a buffer solution and finding the equilibrium pH in acid–base reactions. Two equivalent forms of the equation are: pH = pKa + log10 [A–]/[HA] or pH = pKa + log10 [base]/[acid]. Here, pKa is − log10(Ka) where Ka is the acid dissociation constant, that is: pKa = –log10(Ka) = –log10 ([H3 O+][A–]/[HA]) for the reaction: HA + H2 O ≈ A– + H3 O+ In these equations, A– denotes the ionic form of the relevant acid. Bracketed quantities such as [base] and [acid] denote the molar concentration of the quantity enclosed. Maximum buffering capacity is found when pH = pKa or when the number of free anions to undissociated acid is equal and buffer range is considered to be at a pH = pKa ± 1.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 27
Incorrect
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The wound healing process is documented in patients undergoing laparoscopic procedures. The port incisions are sutured closed and the wounds observed every few weeks for re-epithelialisation and tensile strength. Which substance is mostly likely to be found at a cellular level involved in wound healing?
Your Answer: Hyaluronic acid
Correct Answer: Tyrosine kinase
Explanation:Cell surface growth factor receptors require intercellular proteins such as tyrosine kinase which are necessary to initiate a series of events that eventually lead to cell division and growth. Tyrosine kinase is an enzyme that transfers a phosphate group to the tyrosine residue in a protein. This phosphorylation will lead to an up regulation of the enzyme activity.
Fibronectin acts in the extracellular matrix to bind macromolecules (such as proteoglycans) via integrin receptors to aid attachment and migration of cells.
Laminin is an extracellular matrix component that is abundant in basement membranes.
Hyaluronic acid is one of the proteoglycans in the extracellular matrix.
Collagen fibres are part of the extracellular matrix that gives strength and stability to connective tissues.
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This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
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Question 28
Correct
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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 29
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 30
Correct
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After being admitted to the hospital, a 60-year-old man is administered sodium nitroprusside. Which class of drugs does nitroprusside belong to?
Your Answer: Vasodilators
Explanation:Sodium nitroprusside is a potent peripheral vasodilator that affects both arterioles and venules. It is often administered intravenously to patients who are experiencing a hypertensive emergency. It reduces both total peripheral resistance as well as venous return, so decreasing both preload and afterload. For this reason it can be used in severe cardiogenic heart failure where this combination of effects can act to increase cardiac output. It is administered by intravenous infusion. Onset is typically immediate and effects last for up to ten minutes. The duration of treatment should not exceed 72 hours.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 31
Correct
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An old man was diagnosed with squamous cell carcinoma with axillary lymph node metastasis. The doctor said he will excise the tumour and remove all axillary lymph nodes lateral to the edge of the pectoralis minor muscle. One of the following axillary lymph nodes won't be removed by this procedure. Which is it?
Your Answer: Apical
Explanation:The apical lymph node group won’t be removed which include 20 to 30 lymph nodes.
Axillary lymph nodes are grouped according to location. The lateral group, the anterior to pectoral group, the posterior or subscapular group, the central group, and the medial or apical group. The lateral, pectoral, and subscapular groups are found lateral to the pectoralis minor muscle. The central group is situated directly under that muscle. Thus, if all lymph nodes lateral to the medial edge of the pectoralis minor muscle are removed, all the above four groups will be removed. The apical group won’t be removed which is situated medial to the medial edge of the pectoralis minor muscle.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 32
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 33
Correct
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What is a major source of fuel being oxidised by the skeletal muscles of a man who has undergone starvation for 7 days?
Your Answer: Serum fatty acids
Explanation:Starvation is the most extreme form of malnutrition. Prolonged starvation can lead to permanent organ damage and can be fatal. Starved individuals eventually lose significant fat and muscle mass as the body uses these for energy.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 34
Correct
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A 20-year old involved in a brawl was stabbed in the anterior chest in a structure that is in close proximity to where the first rib articulates with the sternum. What is the structure that was most likely injured?
Your Answer: Sternoclavicular joint
Explanation:The first rib articulates with the sternum right below the sternoclavicular joint.
The sternal angle articulates with the costal cartilage of the second rib.
The nipple is found between the fourth and the fifth ribs, in the fourth intercostal space.
The xiphoid process is located right below the point of articulation of the costal cartilage of rib 7 with the sternum.
The root of the lung is the part of the lung where neurovascular structures enter and leave the lung.
Acromioclavicular joint is the point of articulation between the acromion process and the clavicle, near the shoulder.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 35
Correct
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The pattern of drainage of the lymphatic and venous systems of the anterior abdominal wall is arranged around a horizontal plane above which drainage is in a cranial direction and below which drainage is in a caudal direction. Which horizontal plane is being referred to?
Your Answer: Level of the umbilicus
Explanation:The umbilicus is a key landmark for the lymphatic and venous drainage of the abdominal wall. Above it, lymphatics drain into the axillary lymph nodes and the venous blood drains into the superior epigastric vein, into the internal thoracic vein. Below it, lymphatics drain into the superficial inguinal lymph nodes while venous blood drains into the inferior epigastric vein and the external iliac vein.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 36
Incorrect
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A 55-year-old male has a mass on the right lung with involvement of the right mediastinal lymph nodes. What is the nodal staging according to the TNM staging?
Your Answer: N1
Correct Answer: N2
Explanation:The N stages for lung cancer are from NO to N3 : NO, there is no lung cancer in any lymph nodes: N1, there is lung cancer in the proximal lymph nodes: N2, there is lung cancer in the mediastinal hilar lymph nodes, but on the same side as the affected lung or there is lung cancer in the carinal lymph nodes: N3, there is metastatic lung cancer in lymph nodes on the opposite side of the chest, in the cervical or apical lymph nodes. In this patient the ipsilateral mediastinal node is involved, thus it is classified as N2.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 37
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 38
Correct
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When the pitch of a sound increases, what is the physiological response seen in the listener?
Your Answer: The location of maximal basilar membrane displacement moves toward the base of the cochlea
Explanation:An increase in the frequency of sound waves results in a change in the position of maximal displacement of the basilar membrane in the cochlea. Low pitch sound produces maximal displacement towards the cochlear apex and greatest activation of hair cells there. With an increasing pitch, the site of greatest displacement moves towards the cochlear base. However, increased amplitude of displacement, increase in the number of activated hair cells, increased frequency of discharge of units in the auditory nerve and increase in the range of frequencies to which such units respond, are all seen in increases in the intensity or a sound stimulus.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 39
Correct
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A victim of mob justice was brought to the A & E with a stab wound in the anterior chest 2 cm lateral to the left sternal border. He underwent an emergency thoracotomy that revealed clots in the pericardium, with a puncture wound in the right ventricle. To evacuate the clots from the pericardial cavity the surgeon slipped his hand behind the heart at its apex. He extended his finger upwards until its tip was stopped by a line of pericardial reflection which forms the:
Your Answer: Oblique pericardial sinus
Explanation:Transverse sinus: part of pericardial cavity that is behind the aorta and pulmonary trunk and in front of the superior vena cava separating the outflow vessels from the inflow vessels.
Oblique pericardial sinus: is behind the left atrium where the visceral pericardium reflects onto the pulmonary veins and the inferior vena cava. Sliding a finger under the heart will take you to this space.
Cardiac notch: indentation of the ‘of the heart’ on the superior lobe of the left lung.
Hilar reflection: the reflection of the pleura onto the root of the lung to continue as mediastinal pleura.
Costomediastinal recess: part of the pleural sac where the costal pleura transitions to become the mediastinal pleura.
Sulcus terminalis: a groove between the right atrium and the vena cava
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 40
Correct
-
After surgery, a patient developed a stitch granuloma . Which leukocyte in the peripheral blood will become an activated macrophage in this granuloma?
Your Answer: Monocyte
Explanation:Monocytes are leukocytes that protect the body against infections and move to the site of infection within 8-12 hours to deal with it. They are produced in the bone marrow and shortly after being produced are released into the blood stream where they circulate until an infection is detected. When called upon they leave the circulation and transform into macrophages within the tissue fluid and thus gain the capability to phagocytose the offending substance. Monocyte count is part of a complete blood picture. Monocytosis is the state of excess monocytes in the peripheral blood and may be indicative of various disease states. Examples of processes that can increase a monocyte count include: • chronic inflammation • stress response • hyperadrenocorticism • immune-mediated disease • pyogranulomatous disease • necrosis • red cell regeneration.
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This question is part of the following fields:
- General
- Physiology
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Question 41
Correct
-
The vascular structure found on the right side of the fifth lumbar vertebra is?
Your Answer: Inferior vena cava
Explanation:The most likely vascular structure is the inferior vena cava. The inferior vena cava is formed by the joining of the two common iliac arteries, the right and the left iliac artery, at the level of the fifth lumbar vertebra( L5). The inferior vena cava passes along the right side of the vertebral column. It enters the thoracic cavity into the underside of the heart through the caval opening of the diaphragm at the level of the eight thoracic vertebra (T8).
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 42
Correct
-
Pain in the epigastric region occurring typically 2-3 hours after meals and causing the patient to wake up at night is characteristic of which of the following conditions?
Your Answer: Duodenal ulcer
Explanation:The description is typical for duodenal ulcers. There is no pain upon waking in the morning however it appears around mid-morning and is relieved by ingestion of food. The pain also often causes the patient to wake up at night.
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This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
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Question 43
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 44
Correct
-
During an operation to repair an indirect inguinal hernia, it is noticed that the hernial sac is protruding out of the superficial inguinal ring. The superficial inguinal ring is an opening in which structure?
Your Answer: External abdominal oblique aponeurosis
Explanation:The superficial inguinal ring is an opening in the aponeurosis of the external oblique just above and lateral to the pubic crest. The opening is oblique and corresponds to the fibres of the aponeurosis. It is bound inferiorly by the pubic crest, on either side by the margins of the opening in the aponeurosis and superiorly by the curved intercrural fibres.
The inferior crus is formed by the portion of the inguinal ligament that is inserted into the pubic tubercle.
The falx inguinalis is made of arching fibres of the transversalis fascia and the internal abdominal oblique muscle. It forms the posterior wall of the inguinal canal.
The internal abdominal oblique forms the root of the inguinal canal.
Scarpa’s and Camper’s fascia are the membranous and fatty layers, respectively of subcutaneous fascia.
Transversalis fascia covers the posterior surface of the rectus abdominis muscle inferior to the arcuate line.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 45
Correct
-
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 46
Correct
-
Decreased velocity of impulse conduction through the atrioventricular node (AV node) in the heart will lead to:
Your Answer: Increased PR interval
Explanation:AV node damage may lead to an increase in the PR interval to as high as 0.25 – 0.40 s (normal = 0.12 – 0.20 s). In the case of severe impairment, there might be a complete failure of passage of impulses leading to complete block. In this case, the atria and ventricles will beat independently of each other.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 47
Incorrect
-
When exposing the right saphenofemoral junction for flush-ligation of the saphenous vein, which of the following is the most likely to be seen passing through this opening?
Your Answer: Genitofemoral nerve
Correct Answer: Superficial external pudendal artery
Explanation:The saphenous opening is an oval opening in the fascia lata. It is covered by the cribriform fascia and It is so called because it is perforated by the great saphenous vein and by numerous blood and lymphatic vessels and the superficial external pudendal artery pierces it.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 48
Incorrect
-
A 50-year-old man is diagnosed with emphysema and cirrhosis of the liver. Which of the following condition may be the cause of both cirrhosis and emphysema in this patient?
Your Answer: Cystic fibrosis
Correct Answer: Alpha1-antitrypsin deficiency
Explanation:Alpha-1 antitrypsin (A1AT) deficiency is a condition characterised by the lack of a protein that protects the lungs and liver from damage, called alpha1-antytripsin. The main complications of this condition are liver diseases such as cirrhosis and chronic hepatitis, due to accumulation of abnormal alpha 1-antytripsin and emphysema due to loss of the proteolytic protection of the lungs.
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This question is part of the following fields:
- Pathology
- Respiratory
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Question 49
Incorrect
-
Which of the following veins is prostate cancer most likely to metastasize through?
Your Answer: External iliac vein
Correct Answer: Internal vertebral venous plexus
Explanation:The internal vertebral veins are the most likely route of metastasis as they are valveless. They serve an important clinical role as they are the route of free travel for cancerous cells to other body structures. The other veins on the list have valves and would be the least likely routes for metastasis.
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This question is part of the following fields:
- Anatomy
- Neurology
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Question 50
Correct
-
A 25-year-old woman complains of generalised swelling and particularly puffiness around the eyes which is worst in the morning. Laboratory studies showed:
Blood urea nitrogen (BUN) = 30 mg/dl
Creatinine = 2. 8 mg/dl
Albumin = 2. 0 mg/dl
Alanine transaminase (ALT) = 25 U/l
Bilirubin = 1 mg/dl
Urine analysis shows 3+ albumin and no cells.
Which of the following is the most likely diagnosis?Your Answer: Nephrotic syndrome
Explanation:Nephrotic syndrome is a disorder in which the glomeruli have been damaged, characterized by:
– Proteinuria (>3.5 g per 1.73 m2 body surface area per day, or > 40 mg per square meter body surface area per hour in children)
– Hypoalbuminemia (< 2,5 g/dl) – Hyperlipidaemia, and oedema (generalized anasarca).
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This question is part of the following fields:
- Physiology
- Renal
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Question 51
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 52
Correct
-
A 50 year-old man, who sustained a head injury experienced sudden onset of horizontal double vision. He is diagnosed with lateral rectus palsy. Which of the following nerves is affected in this condition?
Your Answer: Abducent
Explanation:The lateral rectus muscle is one of the 6 extra-ocular muscles that control eye movements. It is responsible for abduction and is the only muscle that is innervated by the abducens nerve (CN VI).
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 53
Correct
-
Which of the following key features will be seen in an organ undergoing atrophy?
Your Answer: A greater number of autophagic vacuoles
Explanation:Atrophy is characterised by the breakdown of intracellular components along with organelles and packing them into vacuoles known as autophagic vacuoles. This is an adaptive response that separates the damaged cellular structures from the rest of the cells.
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This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
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Question 54
Correct
-
Which of the following malignancies is associated with the development of Lambert-Eaton myasthenic syndrome?
Your Answer: Lung cancer
Explanation:Lambert–Eaton myasthenic syndrome is a rare disorder of the neuromuscular junction. It can occur as a solitary diagnosis but it can also occur as a paraneoplastic syndrome associated with lung cancer, particularly small-cell histology. It can also be associated with other cancers such as lymphoma, non-Hodgkin’s lymphoma, T-cell leukaemia, non-small-cell lung cancer, prostate cancer and thymoma.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 55
Correct
-
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: 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 56
Incorrect
-
Which best describes the suprascapular nerve?
Your Answer: It courses superior to the suprascapular ligament enroute to the supraspinatus muscle
Correct Answer: It contains nerve fibres from C5 and C6 spinal cord segments
Explanation:The suprascapular nerve arises from the cervical spinal nerves 5 and 6 after coming together to form common trunk. This nerve supplies the supraspinatus and infraspinatus muscles giving off branches to the shoulder joint.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 57
Incorrect
-
The operating surgeon notices a structure lying alongside a herniated mass whilst repairing an indirect inguinal hernia in a female patient. Which structure could this be?
Your Answer: Inferior epigastric artery
Correct Answer: Round ligament of the uterus
Explanation:The main structure traversing the inguinal canal in women is the round ligament. In men, it is the spermatic cord.
The iliohypogastric nerve innervates the abdominal wall and runs between the transversus abdominis and internal oblique muscles before piercing the internal oblique at the anterior superior iliac spine to run between the internal and external obliques.
The inferior epigastric artery is between the peritoneum and the transversus abdominis creating the lateral umbilical fold.
The ovarian artery and the ovarian vein are branches from the descending aorta and inferior vena cava that supply the ovary in the pelvic cavity.
The pectineal ligament is a thick fascial layer over the pectineal line of the pubis. It doesn’t traverse the canal.
The broad ligament if found on the lateral sides of the uterus.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 58
Incorrect
-
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 59
Correct
-
Depression of the normal coagulation system and excessive bleeding after surgery can occur in which of the following medical conditions?
Your Answer: Liver disease
Explanation:As most of the coagulation factors are synthesized in the liver, liver diseases like hepatitis or cirrhosis will depress the coagulation system. Vitamin K deficiency can also decrease the production of vitamin K dependent coagulation factors VII, XI, X and prothrombin.
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This question is part of the following fields:
- General
- Physiology
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Question 60
Incorrect
-
Where does the ejaculatory duct open into?
Your Answer: Membranous urethra
Correct Answer: Prostatic urethra
Explanation:There are two ejaculatory ducts, one on either side of the midline. Each ejaculatory duct is formed by the union of the duct from the seminal vesicles with the ductus deferens. They start at the base of the prostate and run forward and downward between the middle and lateral lobes and along the side of the prostatic utricle to end in the prostatic urethra.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 61
Correct
-
Calculate the cardiac output in an adult male with the following parameters:
Heart rate 70 beats/min
Arterial [O2] 0.24 ml O2/min
Venous [O2] 0.16 ml O2/mi
Whole body O2 consumption 500 ml/min
Pulmonary diastolic pressure 15 mmHg
Pulmonary systolic pressure 25 mmHg
Wedge pressure 5 mmHg.Your Answer: 6.25 l/min
Explanation:As per Fick’s principle, VO2 = (CO × CAO2) – (CO × CVO2) where VO2 = oxygen consumption, CO = cardiac output, CAO2 = oxygen concentration of arterial blood and CVO2 = oxygen concentration of venous blood. Thus, CO = VO2/CAO2– CVO2, CO = 500/0.24 – 0.16, CO = 500/0.8, CO = 6.25 l/min.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 62
Correct
-
The primary somatosensory cortex is located in the:
Your Answer: Postcentral gyrus
Explanation:The primary somatic sensory cortex is located in the postcentral gyrus and is the largest cortical receiving area for information from somatosensory receptors. Through corticocortical fibres, it then sends the information to other areas of the neocortex and further analysis takes place in the posterior parietal association cortex.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 63
Incorrect
-
T lymphocytes that express the MCH type II antigen are most likely to produce which of the following cytokines?
Your Answer: Tumour necrosis factor
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 64
Correct
-
Which of the following diseases can cause paraesthesia along the distribution of the median nerve of the hand, especially after activities which require flexion and extension of the wrist?
Your Answer: Carpal tunnel syndrome
Explanation:Carpal tunnel syndrome tends to occur in women between the ages of 30-50. There are many risk factors, including diabetes, hypothyroidism, obesity, pregnancy, and repetitive wrist work. Symptoms include pain in the hand and wrist, tingling, and numbness distributed along the median nerve (the palmar side of the thumb, the index and middle fingers, and the radial half of the ring finger), which worsens at night.
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This question is part of the following fields:
- Orthopaedics
- Pathology
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Question 65
Correct
-
Which of the following mediators of inflammation requires arachidonic acid for synthesis?
Your Answer: Prostaglandins
Explanation:Arachidonic acid is normally present in the phospholipids that make up the cell membrane and is cleaved by phospholipase A2 from the phospholipid. Arachidonic acid is a precursor for the production of eicosanoids which include: 1) prostaglandins, prostacyclins and thromboxane, 2) leukotrienes and 3) anandamides. The production of these products along with their action on the body is called the arachidonic acid cascade.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 66
Correct
-
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: 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 67
Correct
-
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 68
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 69
Correct
-
A 55- year old male patient with cancer of the head of the pancreas was to undergo whipple's operation to have the tumour removed. During the surgery, the surgeon had to ligate the inferior pancreaticoduodenal artery to stop blood supply to the head of the pancreas. Which of the following arteries does the inferior pancreaticoduodenal artery branch from?
Your Answer: Superior mesenteric artery
Explanation:The inferior pancreaticoduodenal artery is a branch of the superior mesenteric artery or from the first intestinal branch of the superior mesenteric artery. Once given off, it runs to the right between the pancreatic head and the duodenum and then ascends to form an anastomosis with the superior pancreaticoduodenal artery.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 70
Correct
-
A 23 year old woman is Rh -ve and she delivered a baby with a Rh+ blood group. What measure can be performed to prevent Rh incompatibility in the next pregnancy?
Your Answer: Immunoglobulin D
Explanation:Rh disease is also known as erythroblastosis fetalis and is a disease of the new-born. In mild states it can cause anaemia with reticulocytosis and in severe forms causes severe anaemia, morbus hemolytcus new-born and hydrops fetalis. RBCs of the Rh+ baby can cross the placenta and enter into the maternal blood. As she is Rh- her body will form antibodies against the D antigen which will pass through the placenta in subsequent pregnancies.
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This question is part of the following fields:
- General
- Physiology
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Question 71
Correct
-
The muscle which has an antagonistic action to the serratus anterior muscle and is one of the retractors of the scapula is the?
Your Answer: Rhomboid major
Explanation:Protraction is accomplished by the actions of the serratus anterior, pectoralis major, and pectoralis minor muscles. Retraction is accomplished by the actions of the trapezius, rhomboids, and latissimus dorsi muscles.
The rhomboid major arises from the second, third, fourth and fifth thoracic vertebrae. It is inserted into a narrow tendinous arch attached to the root of the spine of the scapula and the inferior angle. By its insertion in the inferior angle of the scapula, it acts on this angle and produces a slight rotation of the scapula on the side of the chest. It also retracts the scapula by working with the trapezius muscle.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 72
Correct
-
A 50 year old woman presented with excessive bleeding after an inguinal hernia repair. Labs are suggestive of a primary haemostasis defect. Deficiency of which of the following is most likely to cause it?
Your Answer: Platelets
Explanation:Primary haemostatic control means the first line of defence against immediate bleeding. This is carried out by the platelets. They immediately form a haemostatic plug at the site of injury. Coagulation starts within 20s after an injury to the blood vessel which damage the endothelial cells. Secondary haemostasis follows which includes activation of the coagulation factors to form fibrin strands which mesh together forming the platelet plug. Platelets interact with platelet collagen receptor, glycoprotein Ia/IIa and to collagen fibres in the vascular endothelium. This adhesion is mediated by von Willebrand factor (vWF), which forms links between the platelet glycoprotein Ib/IX/V and collagen fibrils. The platelets are then activated and release the contents of their granules into the plasma, in turn activating other platelets and white blood cells.
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This question is part of the following fields:
- General
- Physiology
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Question 73
Correct
-
Which of the following can lead to haemolytic anaemia?
Your Answer: Presence of haemoglobin S
Explanation:Haemoglobin S is an abnormal type of haemoglobin seen in sickle cell anaemia. This allows for the haemoglobin to crystalize within the RBC upon exposure to low partial pressures of oxygen. This results in rupture of the RBCs as they pass through microcirculation, especially in the spleen. This can cause blockage of the vessel down stream and ischaemic death of tissues, accompanied by severe pain.
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This question is part of the following fields:
- General
- Physiology
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Question 74
Correct
-
The gynaecologist suspects that her patient has a cervical cancer. What particular test should be done on this patient to screen for cervical cancer?
Your Answer: Pap smear
Explanation:Worldwide, approximately 500,000 new cases of cervical cancer and 274,000 deaths are attributable to cervical cancer yearly. This makes cervical cancer the second most common cause of death from cancer in women. The mainstay of cervical cancer screening has been the Papanicolaou test (Pap smear).
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 75
Correct
-
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 76
Incorrect
-
What is the normal amount of oxygen that is carried in the blood?
Your Answer: 5 ml oxygen/100 ml blood
Correct Answer: 20 ml oxygen/100 ml blood
Explanation:Normally, 100 ml of blood contains 15g haemoglobin and a single gram of haemoglobin can bind to 1.34 ml oxygen when 100% saturated. Thus, 15 × 1.34 = 20 ml O2/100 ml blood. The haemoglobin in venous blood that is leaving the tissues is about 75% saturated with oxygen, and hence it carries about 15 ml O2/100 ml venous blood. This implies that for each 10 ml of blood, 5 ml oxygen is transported to the tissues. With a p(O2) > 100 mm Hg, only 3 ml of oxygen is dissolved in every one litre of plasma. By increasing the pA(O2) by breathing 100% oxygen, one can add an extra amount of oxygen in the plasma, but the amount of oxygen carried by haemoglobin will not increase significantly as it is already > 95% saturated.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 77
Correct
-
A patient is suspected to have Blastomyces dermatidis infection. The patient contracted the disease most likely through which port of entry?
Your Answer: Respiratory tract
Explanation:Blastomycosis disease is a fungal infection acquired through inhalation of the spores. It caused by the organism Blastomyces dermatitidis and manifests as a primary lung infection in about 70% of cases. The onset is relatively slow and symptoms are suggestive of pneumonia.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 78
Incorrect
-
A young 16 year old boy presented to the ENT clinic with a history of sore throat for the past 1 day. On examination there was a pharyngeal purulent discharge. Which of the following types of inflammation is seen in this boy?
Your Answer: Abscess formation
Correct Answer: Acute inflammation
Explanation:A 1 day history suggests the purulent discharge is due to acute inflammation. Acute inflammation has 3 features:
1) the affected area is occupied by a purulent discharge composed of proteins, fluids and cells from local blood vessels
2) the infective agent i.e. bacteria is present in the affected area
3) the damaged tissue can be liquified and the debris removed from the site.
If the inflammation lasts over weeks or months, then it is termed as chronic inflammation.
Granulomatous inflammation is characterised by the presence and formation of granulomas.
Exudate is not a feature of resolution or a complication of inflammation.
Abscess formation takes more than 1 day to form and is usually within a capsule/cavity.
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This question is part of the following fields:
- Inflammation & Immunology; Respiratory
- Pathology
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Question 79
Incorrect
-
Which of the following is the most likely cause of massive splenomegaly in a 35-year old gentleman?
Your Answer: Sickle cell anaemia
Correct Answer: Myelofibrosis
Explanation:Causes of massive splenomegaly include chronic myelogenous leukaemia, chronic lymphocytic leukaemia, lymphoma, hairy cell leukaemia, myelofibrosis, polycythaemia vera, sarcoidosis, Gaucher’s disease and malaria.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 80
Correct
-
The nutcracker effect of the alimentary canal is described as a nutcracker-like compression caused by the aorta and the superior mesenteric arteries on a certain section of the alimentary canal leading to bowel obstruction. Which of the following parts of the alimentary canal is usually obstructed by this nutcracker compression of the two arteries?
Your Answer: Duodenum
Explanation:The ‘nutcracker effect’ is only seen in one part of the alimentary canal, and that is in the third part of the duodenum. This can happen when the superior mesenteric artery that passes across the duodenum and the aorta, posteriorly to the third part of the duodenum enlarges and starts compressing the duodenum. The result is an obstructed duodenum that inhibits passage of food.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 81
Correct
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A 29-year-old pregnant woman develops severe hypoxaemia with petechial rash and confusion following a fracture to her left femur. Which is the most probable cause of these symptoms in this patient?
Your Answer: Fat embolism
Explanation:Fat embolism is a life-threatening form of embolism in which the embolus consists of fatty material or bone marrow particles that are introduced into the systemic venous system. It may be caused by long-bone fractures, orthopaedic procedures, sickle cell crisis, parenteral lipid infusion, burns and acute pancreatitis. Patients with fat embolism usually present with symptoms that include skin, brain, and lung dysfunction.
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This question is part of the following fields:
- Cardiovascular
- Pathology
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Question 82
Incorrect
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All the following statements are FALSE regarding the ophthalmic division of the trigeminal nerve, except:
Your Answer: One of its branches gives motor innervation to the lacrimal gland
Correct Answer: The ophthalmic nerve is the smallest branch of the trigeminal nerve
Explanation:The ophthalmic nerve is the smallest of the three trigeminal divisions. The cutaneous branches of the ophthalmic nerve supply the conjunctiva, the skin over the forehead, the upper eyelid, and much of the external surface of the nose.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 83
Correct
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A 35-year-old ultra marathon runner becomes severely dehydrated and collapses. This patient most likely has:
Your Answer: Decreased baroreceptor firing rate
Explanation:Baroreceptors are sensors located in the blood vessels of all vertebrate animals. They sense the blood pressure and relay the information to the brain, so that a proper blood pressure can be maintained. Acute dehydration results in decreased plasma volume and increased plasma osmolarity, since more water than salt is lost in sweat. The decrease in plasma volume leads to an inhibition of the baroreceptors and a lower firing rate. The increase in plasma osmolarity leads to increased ADH secretion and high plasma ADH levels, which increases water permeability of collecting duct cells. Therefore more water is reabsorbed by the kidneys and renal water excretion is low.
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This question is part of the following fields:
- Physiology
- Renal
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Question 84
Incorrect
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A surgeon ligates the left superior suprarenal artery whilst preforming a left adrenalectomy. Where does the left superior suprarenal artery originate?
Your Answer: Renal artery
Correct Answer: Left inferior phrenic artery
Explanation:The superior suprarenal arteries arises from the inferior phrenic artery on either side.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 85
Correct
-
An excised lesion is found to be a premalignant during examination by the pathologist. What is the most likely histopathology report of this lesion?
Your Answer: Solar keratosis
Explanation:Premalignant condition is a state of disordered morphology of cells that is associated with an increased risk of cancer. If this condition is left untreated, it may lead to the development of cancer. The following are examples of pre-malignant lesions: actinic keratosis, Barret’s oesophagitis, atrophic gastritis, ductal carcinoma in situ, dyskeratosis congenita, sideropenic dysphagia, lichen planus, oral submucous fibrosis, solar elastosis, cervical dysplasia, leucoplakia and erythroplakia.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 86
Correct
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The third branch of the maxillary artery lies in which fossa?
Your Answer: Pterygopalatine fossa
Explanation:The maxillary artery supplies deep structures of the face. It branches from the external carotid artery just deep to the neck of the mandible. It is divided into three portions:
– The first or mandibular portion (or bony portion) passes horizontally forward, between the neck of the mandible and the sphenomandibular ligament.
– The second or pterygoid portion (or muscular portion) runs obliquely forward and upward under cover of the ramus of the mandible, on the surface of the lateral pterygoid muscle; it then passes between the two heads of origin of this muscle and enters the fossa.
– The third portion lies in the pterygopalatine fossa in relation to the pterygopalatine ganglion. This is considered the terminal branch of the maxillary artery. Branches from the third portion includes: the sphenopalatine artery, descending palatine artery, infraorbital artery, posterior superior alveolar artery, artery of pterygoid canal, pharyngeal artery, middle superior alveolar artery and anterior superior alveolar artery.
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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 urologist makes a transverse suprapubic incision to retrieve a stone from the urinary bladder. Which of the following abdominal wall layers will the surgeon NOT traverse?
Your Answer: Posterior rectus sheath
Explanation:Pfannenstiel incision (a transverse suprapubic incision) is made below the arcuate line. Thus, there is no posterior layer of the rectus sheath here, only the transversalis fascia lines the inner layer of the rectus abdominis. The layers traversed include: skin, superficial fascia (fatty and membranous), deep fascia, anterior rectus sheath, rectus abdominis muscle, transversalis fascia, extraperitoneal connective tissue and peritoneum.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 88
Correct
-
An infant, 5 weeks and 6 days old born with a large sub-aortic ventricular septal defect, is prepared for pulmonary artery banding through a left thoracotomy (the child is not fit for a surgical closure). The surgeon initially passes his index finger immediately behind two great arteries in the pericardial sac to mobilise the great arteries in order to pass the tape around the pulmonary artery. Into which space is the surgeon's finger inserted?
Your Answer: Transverse pericardial sinus
Explanation:Cardiac notch: is an indentation on the left lung of the heart.
Coronary sinus: a venous sinus on the surface of the heart (the posterior aspect) that receives blood from the smaller veins that drain the heart.
Coronary sulcus: a groove on the heart between the atria and ventricles.
Transverse pericardial sinus: located behind the aorta and pulmonary trunk and anterior to the superior vena cava.
Oblique pericardial sinus: located behind the left atrium. Accessed from the inferior side (or the apex) of the heart upwards.
Horizontal pericardial sinus: this is a made-up term.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 89
Correct
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A 30 year old female presented in the emergency with an irregular pulse. Her ECG showed absent P-waves with irregular RR interval. What is the most likely diagnosis?
Your Answer: Atrial fibrillation
Explanation:Atrial fibrillation is one of the most common cardiac arrhythmias. It is often asymptomatic but may present with symptoms of palpitations, fainting, chest pain and heart failure. Characteristic findings are: absence of P-waves, unorganised electrical activity in their place, irregularity of RR interval due to irregular conduction of impulses to the ventricles and if paroxysmal AF is suspected, episodes may be documented with the use of Holter monitoring
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 90
Correct
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In a splenectomy procedure, special care is emphasized on the preservation of the tail of the pancreas that is closely associated with the spleen to avoid post operative pancreatic fistula. As a general surgeon conducting a splenectomy where are you most likely to find the tail of the pancreas in the abdominal cavity?
Your Answer: Splenorenal ligament
Explanation:The tail of the pancreas is the only intraperitoneal part of the pancreas and is found contained in the splenorenal ligament of the peritoneal cavity. The splenorenal ligament is derived from the peritoneum where the wall of the general peritoneal cavity connects to the omental bursa between the spleen and the left kidney. This ligament contains the splenic vessels and the tail of the pancreas.
The gastrocolic ligament stretches from the greater curvature of the stomach to the transverse colon, connecting the two.
The gastrosplenic ligament is derived from the greater omentum and is the structure that connects the stomach to the hilum of the spleen. The gastrosplenic ligament continues from the splenic flexure of the colon to the diaphragm and acts as a support to the spleen.
The transverse colon is connected to the abdominal wall by the mesocolon ligament.
The falciform ligament on the other hand, attaches the liver to the ventral wall of the abdomen.
The hepatoduodenal ligament connects the porta hepatis of the liver to the superior part of the duodenum.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 91
Correct
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Etoposide is a chemotherapeutic agent used in the treatment of different types of cancer. Which of the following is the correct indication for this drug?
Your Answer: Lung cancer
Explanation:Etoposide phosphate is an inhibitor of the enzyme topoisomerase II. It is used as a form of chemotherapy for malignancies such as lung cancer, testicular cancer, lymphoma, non-lymphocytic leukaemia and glioblastoma multiforme. Side effects are very common and can include low blood cell counts, vomiting, loss of appetite, diarrhoea, hair loss, and fever.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 92
Correct
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A patient with testicular seminoma has the following tumour markers: LDH 1.3 times the reference levels, β-hCG 4500 mIU/ml and AFP 875 ng/ml. What's the serum tumour marker stage in this case?
Your Answer: S1
Explanation:According to AJCC guidelines, the serum tumour marker staging is the following:
S0: marker studies within normal limits
S1: lactate dehydrogenase (LDH) less than 1.5 times the reference range, beta-human chorionic gonadotrophin (β-hCG) <5000 mIU/ml, and alpha-fetoprotein (AFP) <1000 ng/ml S2: LDH 1.5–10 times the reference range, β-hCG 5000–50,000 mIU/ml or AFP 1000–10,000 ng/ml S3: LDH greater than 10 times the reference range, β-hCG >50,000 mIU/ml or AFP >10,000 ng/ml.
According to this, the patient’s tumour belongs to the S1 stage.
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This question is part of the following fields:
- Pathology
- Urology
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Question 93
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 94
Correct
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Which of the following tumours has the best prognosis following surgery?
Your Answer: Schwannoma
Explanation:Schwannomas are histologically benign neoplasms that arise from nerve sheaths, most commonly from sensory nerve roots. They are generally contained within a capsule, and so can be surgically removed without injuring the associated nerve root. They are histologically benign and less than 1% become malignant.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 95
Correct
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The ostium of the maxillary sinus opens into which of the following structures?
Your Answer: Middle meatus
Explanation:The maxillary sinuses usually develop symmetrically. The maxillary sinus ostium drains into the infundibulum which joins the hiatus semilunaris and drains into the middle meatus.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 96
Correct
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The chest X-ray of an 10-year-old boy, that presented with low-grade fever and cough, revealed hilar enlargement and parenchymal consolidation in the middle lobes. These X-ray findings are more typical for which of the following diagnoses?
Your Answer: Pulmonary tuberculosis
Explanation:Primary pulmonary tuberculosis is seen in patients exposed to Mycobacterium tuberculosis for the firs time. The main radiographic findings in primary pulmonary tuberculosis include homogeneous parenchymal consolidation typically in the lower and middle lobes, lymphadenopathy, miliary opacities and pleural effusion.
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This question is part of the following fields:
- Pathology
- Respiratory
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Question 97
Correct
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A patient sustained an iatrogenic injury to one of the structures passing through the deep inguinal ring. This was during an operation to repair an inguinal hernia. Which structure is most likely to be injured?
Your Answer: Round ligament of the uterus
Explanation:The deep inguinal ring transmits the spermatic cord in the man and the round ligament of the uterus in the female. It is bound below and medially by the inferior epigastric vessels (so these don’t go through it).
The ilioinguinal nerve, although it courses through the inguinal canal, does not pass through it.
The iliohypogastric nerves run between the internal oblique and transversus abdominis in the abdominal wall, piercing the internal oblique at the anterior superior iliac spine to travel just deep to the external oblique.
The inferior epigastric artery runs between the transversus abdominis and the peritoneum forming the lateral umbilical fold.
The medial umbilical ligament is the obliterated umbilical artery that it lies within the medial umbilical fold of peritoneum.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 98
Incorrect
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Injury to this nerve may result in loss of sensation of the mandibular teeth and bone:
Your Answer: Buccal nerve
Correct Answer: Inferior alveolar nerve
Explanation:The inferior alveolar nerve (sometimes called the inferior dental nerve) is a branch of the mandibular nerve, which is itself the third branch of the trigeminal nerve. The inferior alveolar nerves supply sensation to the lower teeth of the mandible.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 99
Incorrect
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A 65-year-old female is taking different medications for various medical conditions. Which medication would most likely predispose the patient to develop hyperkalaemia?
Your Answer: Thiazide diuretic
Correct Answer: Spironolactone
Explanation:The most important potential side effect of spironolactone is hyperkalaemia (high potassium levels), which, in severe cases, can be life-threatening. Hyperkalaemia in these patients can present as a non anion-gap metabolic acidosis.Â
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This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
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Question 100
Correct
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Calculate the cardiac output of a patient with the following measurements: oxygen uptake 200 ml/min, oxygen concentration in the peripheral vein 7 vol%, oxygen concentration in the pulmonary artery 10 vol% and oxygen concentration in the aorta 15 vol%.
Your Answer: 4000 ml/min
Explanation:The Fick’s principle states that the uptake of a substance by an organ equals the arteriovenous difference of the substance multiplied by the blood flowing through the organ. We can thus calculate the pulmonary blood flow with pulmonary arterial (i.e., mixed venous) oxygen content, aortic oxygen content and oxygen uptake. The pulmonary blood flow, systemic blood flow and cardiac output can be considered the same assuming there are no intracardiac shunts. Thus, we can calculate the cardiac output. Cardiac output = oxygen uptake/(aortic − mixed venous oxygen content) = 200 ml/min/(15 ml O2/100 ml − 10 ml O2/100 ml) = 200 ml/min/(5 ml O2/100 ml) = 200 ml/min/0.05 = 4000 ml/min.
It is crucial to remember to use pulmonary arterial oxygen content and not peripheral vein oxygen content, when calculating the cardiac output by Fick’s method.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 101
Correct
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During thyroidectomy, the recurrent laryngeal nerves are vulnerable to injury. Which of the following muscles will not be affected in cases where the recurrent laryngeal nerve is severed?
Your Answer: Cricothyroid
Explanation:All muscles of the larynx are supplied by the recurrent laryngeal nerve except for the cricothyroid which is supplied by the vagus nerve.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 102
Incorrect
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Passing through the lesser sciatic foramen are the:
Your Answer: Nerve to quadratus femoris
Correct Answer: Pudendal nerve
Explanation:Structures that pass through the lesser sciatic foramen include:
– the pudendal nerve
– the nerve to obturator internus
– internal pudendal artery
– the tendon of obturator internus
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 103
Correct
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In which of the following conditions will the oxygen-haemoglobin dissociation curve shift to the right?
Your Answer: Exercise
Explanation:The oxygen-haemoglobin dissociation curve plots saturated haemoglobin against the oxygen tension and is usually a sigmoid plot. Each molecule of haemoglobin can bind to four molecules of oxygen reversibly. Factors that can influence the binding include: pH, concentration of 2,3-diphosphoglycerate (2,3-DPG), temperature, type of haemoglobin molecules, and presence of toxins, especially carbon monoxide. Shape of the curve is due to interaction of bound oxygen molecules with the incoming molecules. The binding of first molecule is difficult, with easier binding of the second and third molecule and increase in difficulty with the fourth molecule – partly as a result of crowding and partly as a natural tendency of oxygen to dissociate.
Left shift of curve indicates haemoglobin’s increased affinity for oxygen (seen at lungs). Right shift indicates decreased affinity and is seen with an increase in body temperature, hydrogen ions, 2,3-diphosphoglycerate (DPG), carbon dioxide concentration and exercise. Under normal resting conditions in a healthy individual, the normal position of the curve is at a pH of 7.4. A shift in the position of the curve with a change in pH is called the Bohr effect. Left shift occurs in acute alkalosis, decrease in p(CO2), decrease in temperature and decrease in 2,3-DPG. The fetal haemoglobin curve is to the left of the adult haemoglobin to allow for oxygen diffusion across the placenta. The curve for myoglobin is even further to the left. Carbon monoxide has a much higher affinity for haemoglobin than oxygen does. Thus, carbon monoxide poisoning leads to hypoxia.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 104
Correct
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A 36-year-old woman suddenly suffers from a generalized seizure. She was previously healthy. An emergency CT scan reveals a mass in the posterior fossa, with distortion of the lateral ventricles. After removing the tumour, the biopsy reveals it contains glial fibrillary acidic protein (GEAP). What's the most likely diagnosis?
Your Answer: Astrocytoma
Explanation:Astrocytomas are primary intracranial tumours derived from astrocyte cells of the brain. They can arise in the cerebral hemispheres, in the posterior fossa, in the optic nerve and, rarely, in the spinal cord. These tumours express glial fibrillary acidic protein (GFAP). In almost half of cases, the first symptom of an astrocytoma is the onset of a focal or generalised seizure. Between 60% and 75% of patients will have recurrent seizures during the course of their illness. Secondary clinical sequelae may be caused by elevated intracranial pressure (ICP) cause by the direct mass effect, increased blood volume, or increased cerebrospinal fluid (CSF) volume. CT will usually show distortion of the third and lateral ventricles, with displacement of the anterior and middle cerebral arteries. Histological diagnosis with tissue biopsy will normally reveal an infiltrative character suggestive of the slow growing nature of the tumour.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 105
Correct
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A 50-year-old woman goes to the doctor complaining of myalgia, muscle cramps, and weakness; she is diagnosed with severe hypokalaemia. Which of the following is the most common cause of hypokalaemia?
Your Answer: Prolonged vomiting
Explanation:Potassium is one of the body’s major ions. Nearly 98% of the body’s potassium is intracellular. The ratio of intracellular to extracellular potassium is important in determining the cellular membrane potential. Small changes in the extracellular potassium level can have profound effects on the function of the cardiovascular and neuromuscular systems. Hypokalaemia may result from conditions as varied as renal or gastrointestinal (GI) losses, inadequate diet, transcellular shift (movement of potassium from serum into cells) and medications. The important causes of hypokalaemia are:
Renal losses: renal tubular acidosis, hyperaldosteronism, magnesium depletion, leukaemia (mechanism uncertain).
GI losses: vomiting or nasogastric suctioning, diarrhoea, enemas or laxative use, ileal loop.
Medication effects: diuretics (most common cause), β-adrenergic agonists, steroids, theophylline, aminoglycosides.
Transcellular shift: insulin, alkalosis.
Severe hypokalaemia, with serum potassium concentrations of 2.5–3 meq/l, may cause muscle weakness, myalgia, tremor, muscle cramps and constipation.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 106
Correct
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A 55-year-old male chronic smoker is diagnosed with non-small-cell cancer. His right lung underwent complete atelectasis and he has a 7cm tumour involving the chest wall. What is the stage of the lung cancer of this patient?
Your Answer: T3
Explanation:Non-small-cell lung cancer is staged through TNM classification. The stage of this patient is T3 because based on the TNM classification the tumour is staged T3 if > 7 cm or one that directly invades any of the following: Chest wall (including superior sulcus tumours), diaphragm, phrenic nerve, mediastinal pleura, or parietal pericardium; or the tumour is in the main bronchus < 2 cm distal to the carina but without involvement of the carina, Or it is associated with atelectasis/obstructive pneumonitis of the entire lung or separate tumour nodule(s) in the same lobe.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 107
Incorrect
-
Hormones of the anterior pituitary include which of the following?
Your Answer: Antidiuretic hormone (ADH)
Correct Answer: Prolactin
Explanation:The anterior pituitary gland (adenohypophysis or pars distalis) synthesizes and secretes:
1. FSH (follicle-stimulating hormone)
2. LH (luteinizing hormone)
3. Growth hormone
4. Prolactin
5. ACTH (adrenocorticotropic hormone)
6. TSH (thyroid-stimulating hormone).
The posterior pituitary gland (neurohypophysis) stores and secretes 2 hormones produced by the hypothalamus:
1. ADH (antidiuretic hormone or vasopressin)
2. Oxytocin
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 108
Correct
-
One of the following structures is contained in the anterior compartment of the lower leg. Which is it?
Your Answer: Extensor hallucis muscle
Explanation:The lower leg is made up of four fascial compartments separated from one another by septa that contain the muscles of the lower leg. The four compartments are ; anterior, lateral, deep posterior and superficial posterior compartments.
These are the compartments and there contents:
i) Anterior compartment: Tibialis anterior muscle, extensor hallucis longus muscle, extensor digitorum longus muscle, peroneus tertius muscles, deep fibular nerve and anterior tibial blood vessels
ii) Lateral compartment: Fibularis longus muscle, brevis muscles and superficial fibular nerve
iii) Deep posterior compartment: Tibialis posterior m., flexor hallucis longus m., flexor digitorum longus m. ,popliteus m. , tibial nerve, posterior tibial artery and posterior tibial vessels such as the fibular artery.
iv) Superficial posterior compartment: Gastrocnemius m., soleus m., plantaris m., medial sural cutaneous nerve
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 109
Correct
-
Which lymph nodes are likely to be enlarged in a patient who has malignant growth involving the anus?
Your Answer: Superficial inguinal
Explanation:The lymphatics from the anus, skin of the perineum and the scrotum end in the superficial inguinal nodes. In case of a malignant growth of the anus, the superficial inguinal lymph nodes would most likely be enlarge.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 110
Correct
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A 58-year-old woman presents with signs of inflammation in the first metatarsophalangeal joint: redness, swelling and pain. The analysis of synovial fluid reveals needle-shaped, strongly negatively birefringent crystals. What's the most likely diagnosis in this case?
Your Answer: Gout
Explanation:Gout is a rheumatic disease caused by the precipitation of monosodium urate crystals into tissues, usually joints. This causes acute or chronic pain; the acute illness initially affects only one joint, often the first metatarsophalangeal joint. The diagnosis of the disease requires the identification of crystal in the synovial fluid. These crystals are needle-shaped and strongly negatively birefringent.
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This question is part of the following fields:
- Orthopaedics
- Pathology
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Question 111
Incorrect
-
Which is the correct superficial to deep order of structures that would be affected following a knife wound to the lateral aspect of the knee?
Your Answer: Skin, tibial collateral ligament, lateral meniscus
Correct Answer: skin, fibular collateral ligament, popliteus muscle tendon, lateral meniscus
Explanation:Skin, fibular collateral ligament, popliteus muscle tendon and lateral meniscus is the correct order of structures covering the lateral aspect of the knee joint from a superficial to deep.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 112
Correct
-
Which of the following conditions can present with multiple abscesses that may discharge sulphur granules?
Your Answer: Actinomycosis
Explanation:Actinomycosis is primarily caused by any of the several members of the bacterial genus Actinomyces. These bacteria are generally anaerobes. And can cause multiple abscesses that may discharge sulphur granules.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 113
Correct
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What is the nerve supply of the muscle that is inserted onto the crest of the lesser tubercle of the humerus?
Your Answer: Lower subscapular
Explanation:The muscle is the subscapularis muscle which is supplied by the lower subscapular nerve.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 114
Correct
-
Which of the following is the cause of flattened (notched) T waves on electrocardiogram (ECG)?
Your Answer: Hypokalaemia
Explanation:The T-wave is formed due to ventricular repolarisation. Normally, it is seen as a positive wave. It can be normally inverted (negative) in V1 (occasionally in V2-3 in African-Americans/Afro-Caribbeans). Hyperacute T-waves are the earliest ECG change of acute myocardial infarction. ECG findings of hyperkalaemia include high, tent-shaped T-waves, a small P-wave and a wide QRS complex. Hypokalaemia results in flattened (notched) T-waves, U-waves, ST-segment depression and prolonged QT interval.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 115
Correct
-
The Brunner glands secrete an alkaline product that helps maintain an optimal pH for pancreatic enzyme activity. Where are these glands located?
Your Answer: Submucosa of the duodeneum
Explanation:The Brunner glands are located in the submucosa of the duodenum. These glands are connected to the interstitial lumen by ducts that open into certain crypts. They secrete an alkaline product that protects the duodenal mucosa from the acidic chyme and helps achieve an optimal pH for the enzymes.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 116
Correct
-
A retroperitoneal structure is:
Your Answer: Pancreas
Explanation:Retroperitoneal structures are those that are found behind the peritoneum. They include: kidneys, suprarenal glands, bladder, ureter, inferior vena cava, rectum, oesophagus (part of it), part of the pancreas, 2nd, 3rd and 4th parts of the duodenum and ascending and descending parts of the colon.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 117
Correct
-
Which is the correct statement regarding gonadal venous drainage:
Your Answer: The left ovarian vein drains into the left renal vein
Explanation:Spermatic or testicular veins arise from the posterior aspect of the testis and receive tributaries from the epididymis. Upon uniting, they form the pampiniform plexus that makes up the greater mass of the spermatic cord. The vessels that make up this plexus rise up the spermatic cord in front of the ductus deferens. They then unite, below the superficial ring, to form three or four veins that traverse the inguinal canal and enter the abdomen through the deep inguinal ring. They further unite to form 2 veins that ascend up the psoas major muscle behind the peritoneum each lying on either side of the testicular artery. These further unite to form one vein that empties on the right side of the inferior vena cava at an acute angle and on the left side into the renal vein, at a right angle. The left testicular vein courses behind the iliac colon and is thus exposed to pressure from the contents of this part of the bowel. The ovarian vein is the equivalent of the testicular vein in women. They form a plexus in the broad ligament near the ovary and uterine tube and communicate with the uterine plexus. They drain into similar vessels as in a man.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 118
Correct
-
Where is factor VIII predominantly synthesised?
Your Answer: Vascular endothelium
Explanation:Factor VIII is an important part of the coagulation cascade. Deficiency causes haemophilia A. It is synthesised predominantly by the vascular endothelium and is not affected by liver disease. In the circulation it is bound to von Willebrand factor and it forms a stable complex with it. It is activated by thrombin or factor Xa and acts as a co factor to factor IXa to activate factor X which is a co factor to factor Va. Thrombin cleaves fibrinogen in fibrin and forms a meshwork to trap RBC and platelets to form a clot.
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This question is part of the following fields:
- General
- Physiology
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Question 119
Correct
-
A 30-year-old man is brought to the emergency department suffering from extreme dehydration, and subsequent hypotension and tachycardia. Which part of the kidney will compensate for this loss?
Your Answer: Collecting ducts
Explanation:The collecting duct system of the kidney consists of a series of tubules and ducts that physically connect nephrons to a minor calyx or directly to the renal pelvis. The collecting duct system is the last component of the kidney to influence the body’s electrolyte and fluid balance. In humans, the system accounts for 4–5% of the kidney’s reabsorption of sodium and 5% of the kidney’s reabsorption of water. At times of extreme dehydration, over 24% of the filtered water may be reabsorbed in the collecting duct system.
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This question is part of the following fields:
- Physiology
- Renal
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Question 120
Correct
-
Whilst snorkelling, a 30-year old gentleman has the respiratory rate of 10/min, tidal volume of 550 ml and an effective anatomical dead space of 250 ml. Which of the following will bring about a maximum increase in his alveolar ventilation?
Your Answer: A 2x increase in tidal volume and a shorter snorkel
Explanation:Alveolar ventilation = respiratory rate × (tidal volume − anatomical dead space volume). Increase in respiratory rate simply causes movement of air in the anatomical dead space, with no contribution to the alveolar ventilation. By use of a shorter snorkel, the effective anatomical dead space will decrease and will cause a maximum rise in alveolar ventilation along with doubling of tidal volume.
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This question is part of the following fields:
- Physiology
- Respiratory
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SESSION STATS - PERFORMANCE PER SPECIALTY
