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Question 1
Incorrect
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A 49-year-old woman with acute renal failure has a total plasma [Ca2+] = 2. 5 mmol/l and a glomerular filtration rate of 160 l/day. What is the estimated daily filtered load of calcium?
Your Answer: 64 mmol/day
Correct Answer: 240 mmol/day
Explanation:Calcium is the most abundant mineral in the human body. The average adult body contains in total approximately 1 kg of calcium of which 99% is in the skeleton in the form of calcium phosphate salts. The extracellular fluid (ECF) contains approximately 22 mmol, of which about 9 mmol is in the plasma. About 40% of total plasma Ca2+ is bound to proteins and not filtered at the glomerular basement membrane. Therefore, the estimated daily filtered load is 1.5 mmol/l × 160 l/day = 240 mmol/day. The exact amount of free versus total Ca2+ depends on the blood pH: free Ca2+ increases during acidosis and decreases during alkalosis.
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This question is part of the following fields:
- Physiology
- Renal
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Question 2
Correct
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Which of the following will be a seen in a patient with a plasma thyroid-stimulating hormone (TSH) level of 14 mU/l (normal < 5 mU/l) and a low T3 resin uptake of 19% (normal 25–35%)?
Your Answer: Periorbital swelling and lethargy
Explanation:Low T3 resin uptake combined with raised TSH is indicative of hypothyroidism. Signs and symptoms include dull expression, facial puffiness, lethargy, periorbital swelling due to infiltration with mucopolysaccharides, bradycardia and cold intolerance. Anxiety, palpitations, tachycardia, raised body temperature, heat intolerance and weight loss are all seen in hyperthyroidism.
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This question is part of the following fields:
- Endocrinology
- Physiology
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Question 3
Correct
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Where does the ejaculatory duct open into?
Your Answer: Prostatic urethra
Explanation:There are two ejaculatory ducts, one on either side of the midline. Each ejaculatory duct is formed by the union of the duct from the seminal vesicles with the ductus deferens. They start at the base of the prostate and run forward and downward between the middle and lateral lobes and along the side of the prostatic utricle to end in the prostatic urethra.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 4
Incorrect
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The sciatic nerve does NOT supply which of the following muscles?
Your Answer: Biceps femoris
Correct Answer: Obturator externus
Explanation:The sciatic nerve supplies both gemellae, quadratus femoris, semitendinosus, semimembranosus, both heads of the biceps femoris, the hamstring half of abductor magnus and obturator internus. Obturator externus is supplied by the obturator nerve.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 5
Correct
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An 18 -year-old female is diagnosed with folliculitis in the left axilla. What is the most likely organism that could cause this condition?
Your Answer: Staphylococcus aureus
Explanation:Folliculitis is the inflammation of the hair follicles. It is usually caused by Staphylococcus infection.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 6
Correct
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Which best describes the sartorius muscle?
Your Answer: Will flex the leg at the knee joint
Explanation:The sartorius muscle arises from tendinous fibres from the superior iliac spine. It passes obliquely across the thigh from lateral to medial and is inserted into the upper part of the medial side of the tibia. When the sartorius muscle contracts it will flex the leg at the knee joint.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 7
Correct
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A 7-year old child from a rural setting complains of recurrent abdominal pain. The child is found to have a heavy parasitic infestation and anaemia. Which type of anaemia is most likely seen in this patient?
Your Answer: Iron deficiency anaemia
Explanation:The most common cause of iron deficiency anaemia in children in developing countries is parasitic infection (hookworm, amoebiasis, schistosomiasis and whipworm).
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 8
Incorrect
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The mechanism of action of streptokinase involves:
Your Answer: Direct lysis of the clot
Correct Answer: Direct conversion of plasminogen to plasmin
Explanation:Streptokinase is an enzyme that is produced by group A beta haemolytic streptococcus and is an effective and cost efficient method for the dissolution of a clot used in cases of MI and pulmonary embolism. It works by directly converting plasminogen to plasmin which breaks down the blood components in the clot and fibrin, dissolving the clot. Streptokinase is a bacterial product and thus the body will develop immunity against it.
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This question is part of the following fields:
- General
- Physiology
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Question 9
Correct
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A 55- year old male patient with cancer of the head of the pancreas was to undergo whipple's operation to have the tumour removed. During the surgery, the surgeon had to ligate the inferior pancreaticoduodenal artery to stop blood supply to the head of the pancreas. Which of the following arteries does the inferior pancreaticoduodenal artery branch from?
Your Answer: Superior mesenteric artery
Explanation:The inferior pancreaticoduodenal artery is a branch of the superior mesenteric artery or from the first intestinal branch of the superior mesenteric artery. Once given off, it runs to the right between the pancreatic head and the duodenum and then ascends to form an anastomosis with the superior pancreaticoduodenal artery.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 10
Correct
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13 year old girl developed sun burnt cheeks after spending the day playing on the beach. What is the underlying mechanism to her injury?
Your Answer: Free radical injury
Explanation:Free radicals are a by-product of chemical reactions with an unpaired electron in their outer most shell. They are capable of causing wide spread damage to cells. They can cause autolytic reactions thereby converting the reactants into free radicals. By absorbing sun light, the energy is used to hydrolyse water into hydroxyl (OH) and hydrogen (H) free radicals which can cause injury by lipid peroxidation of membranes, oxidative modification of proteins and damage to the DNA structure.
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This question is part of the following fields:
- Cell Injury & Wound Healing; Dermatology
- Pathology
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Question 11
Correct
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Investigations in a 40-year old gentleman with splenomegaly reveal the following: haemoglobin 21.5 g/dl, haematocrit 66%, mean corpuscular volume (MCV) 86 fl, mean cell haemoglobin concentration 34 g/dl, mean corpuscular haemoglobin 34.5 pg, platelet count 450 × 109/l, and white blood cell count 12 × 109/l, with 81% polymorphonuclear leukocytes, 4% bands, 3% monocytes, and 7% lymphocytes.
What is the likely diagnosis?Your Answer: Polycythaemia vera
Explanation:The markedly increased haematocrit, along with thrombocytosis and the leucocytosis suggest a myeloproliferative disorder.
Polycythaemia vera is the commonest myeloproliferative disorders occurring more often in males (about 1.4 to 1). The mean age at diagnosis is 60 years (range 15–90 years) with 5% of patients below 40 years at onset. It involves increased production of all cell lines, including red blood cells (independent of erythropoietin), white blood cells and platelets. If confined only to red blood cells, it is known as ‘primary erythrocytosis’. There is an increase in blood volume and hyperviscosity occurs, predisposing to thrombosis. Increased bleeding occurs due to abnormal functioning of platelets. Patients become hypermetabolic, and increased cell turnover leads to hyperuricaemia.
Usually asymptomatic, occasionally symptoms include weakness, pruritus, headache, light-headedness, visual disturbances, fatigue and dyspnoea. Face appears red with engorged retinal veins. Lower extremities appear red and painful, along with digital ischaemia (erythromelalgia). Hepatomegaly is common and massive splenomegaly is seen in 75% patients. Thrombosis can lead to stroke, deep venous thrombosis, myocardial infarction, retinal artery or vein occlusion, splenic infarction (often with a friction rub) or Budd–Chiari syndrome. Gastrointestinal bleeding is seen in 10-20% patients. Hypermetabolism can lead to low-grade fevers and weight loss. Late features include complications of hyperuricaemia (e.g. gout, renal calculi). 1.5% to 10% cases transform to acute leukaemia.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 12
Incorrect
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The orbicularis oculi us a muscle that closes the eyelids. What is the motor innervation of this muscle?
Your Answer: A branch of a nerve that exits through the infraorbital foramen
Correct Answer: A branch of a nerve that exits through the stylomastoid foramen
Explanation:The orbicularis oculi is a muscle in the face that closes the eyelids. It is supplied by zygomatic branch of the facial nerve (cranial nerve VII), which exits through the stylomastoid foramen.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 13
Correct
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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: 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 14
Correct
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A 26-year-old female patient had the following blood report: RBC count = 4. 0 × 106/μl, haematocrit = 27% and haemoglobin = 11 g/dl, mean corpuscular volume (MCV) = 80–100 fl, mean corpuscular haemoglobin concentration (MCHC) = 31–37 g/dl. Which of the following is correct regarding this patient’s erythrocytes:
Your Answer: Normal MCV
Explanation:MCV is the mean corpuscular volume and it is calculated from the haematocrit and the RBC count. It is normally 90 fl. Mean corpuscular haemoglobin concentration (MCHC) [g/dl] = haemoglobin [g/dl]/haematocrit = 11/0.27 = 41 g/dl and is higher than normal range (32 to 36 g/dL).
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This question is part of the following fields:
- General
- Physiology
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Question 15
Correct
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A 66 year old male, was involved in a MVA. He sustained third degree burns to his abdomen and open bleeding wound to his left leg. The patient complains of dizziness. He is a known hypertensive but during examination was found to be hypotensive. His heart rate is 120/min, with regular rhythm. What is the possible cause of his hypotension?
Your Answer: Hypovolaemia
Explanation:Hypovolemia can be recognized by tachycardia, diminished blood pressure, and the absence of perfusion as assessed by skin signs (skin turning pale) and/or capillary refill time. The patient may feel dizzy, faint, nauseated, or very thirsty. Common causes of hypovolemia are loss of blood, loss of plasma which occurs in severe burns and lesions discharging fluid, loss of body sodium and consequent intravascular water which may occur in cases of diarrhoea and vomiting. In this case the cause of patients hypotension is due to hypovolemia from both loss of plasma and blood.
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This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
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Question 16
Correct
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Some substances, such as Chromium-51 and Technetium-99, are freely filtered but not secreted or absorbed by the kidney. In these cases, their clearance rate is equal to:
Your Answer: Glomerular filtration rate
Explanation:If a substance passes through the glomerular membrane with perfect ease, the glomerular filtrate contains virtually the same concentration of the substance as does the plasma and if the substance is neither secreted nor reabsorbed by the tubules, all of the filtered substance continues on into the urine. Glomerular filtration rate (GFR) describes the flow rate of filtered fluid through the kidney.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 17
Incorrect
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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: Lateral cricoarytenoid
Correct 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 18
Incorrect
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The accumulation of eosinophils within tissues is mostly regulated by which of the following cytokines?
Your Answer: Interleukin 3
Correct Answer: Interleukin-5
Explanation:IL-5 is produced by TH2 helper cells and by mast cells. They stimulate increased secretion of immunoglobulins and stimulate B cell growth. They are the major regulators in eosinophil activation and control. They are also released from eosinophils and mast cells in asthmatic patients and are associate with a many other allergic conditions.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 19
Correct
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What is the normal duration of the ST segment?
Your 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 20
Incorrect
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A 30-year-old woman known with Von Willebrand disease (vWD) has to undergo surgery. Which of these complications is most unlikely in this patient?
Your Answer: Easy bruising
Correct Answer: Hemarthrosis
Explanation:Von Willebrand disease (vWD) is an inherited haemorrhagic disorder characterised by the impairment of primary haemostasis. It is caused by the deficiency or dysfunction of a protein named von Willebrand factor. The most common manifestation due to the condition is abnormal bleeding. Complications include easy bruising, hematomas, epistaxis, menorrhagia, prolonged bleeding and severe haemorrhage. Hemarthrosis is a complication that is more commonly found in haemophilia.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 21
Correct
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A 50 year old man on warfarin therapy following insertion of a pacemaker presented with epistaxis. Which of the following is true regarding blood coagulation?
Your Answer: Patients with haemophilia A usually have a normal bleeding time
Explanation:A prolonged bleeding time is seen in platelet disorders like thrombocytopenia. Patients with haemophilia A or B have a prolonged PTT but not a prolonged bleeding time.
Ca2+ is necessary for coagulation.
von Willebrand factor is an important part of the factor VIII complex and promotes platelet adhesion and aggregation.
DIC results in depleted coagulation factors and accumulation of fibrin.
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This question is part of the following fields:
- General
- Physiology
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Question 22
Correct
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A 20 year lady is brought to the A&E following a road accident. She is hypotensive and a CT scan of the abdomen reveals a shattered spleen. An emergency splenectomy is performed where the splenic artery is ligated right at its origin. Which of the following arteries will have a diminished blood flow owing to ligation of the splenic artery at its origin?
Your Answer: Left gastroepiploic
Explanation:Ligation of the splenic artery right at its point of origin should cut off blood flow in its branches. The following are the branches of the splenic artery: pancreatic branches, short gastric branches and left gastroepiploic arteries.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 23
Incorrect
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One of the following structures is contained in the anterior compartment of the lower leg. Which is it?
Your Answer: Superficial peroneal nerve
Correct Answer: Extensor hallucis muscle
Explanation:The lower leg is made up of four fascial compartments separated from one another by septa that contain the muscles of the lower leg. The four compartments are ; anterior, lateral, deep posterior and superficial posterior compartments.
These are the compartments and there contents:
i) Anterior compartment: Tibialis anterior muscle, extensor hallucis longus muscle, extensor digitorum longus muscle, peroneus tertius muscles, deep fibular nerve and anterior tibial blood vessels
ii) Lateral compartment: Fibularis longus muscle, brevis muscles and superficial fibular nerve
iii) Deep posterior compartment: Tibialis posterior m., flexor hallucis longus m., flexor digitorum longus m. ,popliteus m. , tibial nerve, posterior tibial artery and posterior tibial vessels such as the fibular artery.
iv) Superficial posterior compartment: Gastrocnemius m., soleus m., plantaris m., medial sural cutaneous nerve
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 24
Correct
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Which of the following veins is prostate cancer most likely to metastasize through?
Your 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 25
Correct
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In the adult heart, the sinus venosus gives rise to the:
Your Answer: Coronary sinus
Explanation:The sinus venosus is a large quadrangular cavity which precedes the atrium on the venous side of the chordate heart. It exists distinctly only in the embryonic heart (where it is found between the two venae cavae); however, the sinus venosus persists in the adult. In the adult, it is incorporated into the wall of the right atrium to form a smooth part called the sinus venarum, which is separated from the rest of the atrium by a ridge of fibres called the crista terminalis. The sinus venosus also forms the SA node and the coronary sinus.
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This question is part of the following fields:
- Anatomy
- Embryology
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Question 26
Correct
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A 66-year-old man complains of constant headaches. On physical examination, the only relevant sign is a dark brown mole located on left his arm which has grown in size over the years and is itchy and painful. A MRI of the brain revealed a solitary lesion at the grey-white junction in the right frontal lobe, without ring enhancement. This lesion is most likely to be:
Your Answer: Metastatic carcinoma
Explanation:The location of the mass at the grey–white junction is typical of a metastasis. The most frequent types of metastatic brain tumours originate in the lung, skin, kidney, breast and colon. These tumour cells reach the brain via the bloodstream. This patient is likely to have skin cancer, which caused the metastatic brain tumour.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 27
Incorrect
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A 27 year old women had developed a darker complexion following a vacation to India. She had no erythema or tenderness. Her skin colour returned to normal over a period of 1 month. Which of the these substances is related to the biochemical change mentioned above?
Your Answer: Hemosiderin
Correct Answer: Tyrosine
Explanation:The tanning process can occur due to UV light exposure as a result of oxidation of tyrosine to dihydrophenylalanine with the help of the tyrosinase enzyme within the melanocytes. Hemosiderin can impart a brown colour due to breakdown of RBC but its usually due to a trauma and is known as haemochromatosis.
Lipofuscin gives a golden brown colour to the cell granules not the skin.
Homogentisic acid is part of a rare disease alkaptonuria, with characteristic black pigment deposition within the connective tissue.
Copper can impart a brown golden colour, but is not related to UV light exposure.
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This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
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Question 28
Incorrect
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An alcoholic patient was found to have hypomagnesaemia on blood tests. Which of the following clinical features will have prompted the doctor to check the serum magnesium level in this patient?
Your Answer: Weakness
Correct Answer: Seizures
Explanation:Hypomagnesaemia is a condition characterised by a low level of magnesium in the blood. The normal range for serum magnesium level is 0.75-1.05 mmol/l. In hypomagnesaemia serum levels of magnesium are less than 0.75 mmol/l. The cardiovascular and nervous systems are the most commonly affected. Neuromuscular manifestations include symptoms like tremor, tetany, weakness, apathy, delirium, a positive Chvostek and Trousseau sign, nystagmus and seizures. Cardiovascular manifestations include electrocardiographic abnormalities and arrhythmias e.g. ventricular fibrillation.
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This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
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Question 29
Incorrect
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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: Giant-cell tumour of bone
Correct 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 30
Correct
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During an operation to repair an indirect inguinal hernia, you are asked to indicate the position of the deep inguinal ring. You indicate this as being:
Your Answer: Above the midpoint of the inguinal ligament
Explanation:The deep inguinal ring is near the midpoint of the inguinal ligament, below the anterior superior iliac spine. It is lateral to the inferior epigastric artery. The superficial ring, however, is found above the pubic tubercle. The supravesical fossa is the space between the median and medial umbilical folds.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 31
Incorrect
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Which of the following is a likely cause of jaundice?
Your Answer: Haemolytic disease if plasma albumin is low and globulin high
Correct Answer: Hepatic disease if plasma albumin is low and serum aminotransferase elevations > 500 units
Explanation:Jaundice can occur due to any of the possible causes and treatment depends upon diagnosing the correct condition. Mild hyperbilirubinemia with normal levels of aminotransferase and alkaline phosphatase is often unconjugated (e.g., due to haemolysis or Gilbert’s syndrome rather than hepatobiliary disease). Moderate or severe hyperbilirubinemia along with increased urinary bilirubin (bilirubinuria), high alkaline phosphatase or aminotransferase levels suggest hepatobiliary disease. Hyperbilirubinemia produced by any hepatobiliary disease is largely conjugated. In this case, other blood tests include hepatitis serology for suspected hepatitis, prothrombin time (PT) or international normalised ratio (INR), albumin and globulin levels, and antimitochondrial antibody levels (suspected primary biliary cirrhosis). Low albumin and high globulin levels suggest chronic rather than acute liver disease. In cases where there is only a an elevation of alkaline phosphatase, γ-glutamyl transpeptidase (GGT) levels should be checked – the levels of which will be found high in hepatobiliary disease, but not in bone disorder which can also lead to elevated alkaline phosphatase levels. In diseases of hepatobiliary origin, aminotransferase elevations > 500 units suggest a hepatocellular cause, whereas disproportionate increases of alkaline phosphatase (e.g., alkaline phosphatase > 3 times normal and aminotransferase < 200 units) suggest cholestasis. Because hepatobiliary disease alone rarely causes bilirubin levels > 30 mg/dl, higher levels are suggestive of a combination of severe hepatobiliary disease and haemolysis or renal dysfunction. Imaging is best for diagnosing infiltrative and cholestatic causes of jaundice. Liver biopsy is rarely needed, but can be of use in intrahepatic cholestasis and in some types of hepatitis.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 32
Correct
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A 27-year-old woman, who had been taking a combined oral contraceptive for 6 months, presented with inguinal pain and oedema of the left leg. Which of the following investigations would you recommend to help confirm the diagnosis?
Your Answer: Duplex scan
Explanation:Oral combined contraceptive pill (OCCP) is a drug used for birth control and treating a number of other conditions. Women who take the OCP have a higher risk of developing deep vein thrombosis (DVT), usually in the legs. Duplex ultrasonography is a safe and non-invasive technique which is used for diagnosing the presence of lower extremity thrombi.
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This question is part of the following fields:
- Cardiovascular
- Pathology
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Question 33
Correct
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After a total colectomy and ileotomy, a 50-year old diabetic man who was a known case of diabetic nephropathy had persistent metabolic acidosis. The patient appeared well perfused, with normal vital signs and normal fluid balance. Investigations revealed:
Sodium = 132 mmol/l
Potassium = 6.6 mmol/l
Creatinine = 185 μmol/l (2.16 mg/dl)
Chloride = 109 μmol/l
8am cortisol = 500 nmol/l (18 μg/dl)
pH = 7.29, p(CO2) = 27 mmHg
p(O2) = 107 mmHg
standard bicarbonate = 12 mmol/l.
What is the likely causes of his acidosis?Your Answer: Renal tubular acidosis
Explanation:Acidosis here is due to low bicarbonate. The low p(CO2) is seen in compensation. The anion gap is normal, ruling out intra-abdominal ischaemia (which leads to metabolic acidosis). If it was a gastrointestinal aetiology, low potassium would be seen. The history of diabetic nephropathy predisposes to renal tubular acidosis. Type 4 (hyporeninaemic hypoaldosteronism) is associated with high potassium and is found in diabetic and hypertensive renal disease.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 34
Correct
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A pedestrian sustained a left fibula fractured following a hit-and-run. X-rays showed that there was a transverse fracture of the upper end of the fibula. It was manifested clinically by inability to flex his foot at the ankle joint plus weak extension of the phalanges. What nerve is suspected to be injured in such a case?
Your Answer: Deep peroneal
Explanation:The deep peroneal nerve supplies the muscles allowing for flexion of the foot at the ankle joint, namely the tibialis anterior and peroneus tertius muscles. The peroneus tertius, peroneus brevis, and peroneus longus evert the foot, whereas the tibialis anterior and tibialis posterior invert the foot. Fibres of the deep peroneal nerve originate from L4, L5, and S1.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 35
Correct
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Regarding abduction of the digits of the hand, which of the following is correct?
Your Answer: All of the adductors of the digits take at least part of their attachments from metacarpal bones
Explanation:Lying on the palmer surfaces of the metacarpal bones are four palmar interossei which are smaller than the dorsal interossei. Arising from the entire length of the metacarpal bone of one finger, is a palmar interosseous, which is inserted into the side of the base of the first phalanx and the aponeurotic expansion of the extensor digitorum communis tendon to the same finger. All the interossei are innervated by the eighth cervical nerve, through the deep palmar branch of the ulnar nerve. The palmar interossei adducts the fingers to an imaginary line drawn longitudinally through the centre of the middle finger.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 36
Correct
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Which among the following vertebrae marks the lowest extent of the superior mediastinum?
Your Answer: Fourth thoracic
Explanation:The superior mediastinum lies between the manubrium anteriorly and the upper vertebrae of the thorax posteriorly. Below, it is bound by a slightly oblique plane that passes backward from the sternal angle to the lower part of the body of T4 and laterally by the pleura.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 37
Incorrect
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Which of the following conditions can present with multiple abscesses that may discharge sulphur granules?
Your Answer: Brucellosis
Correct 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 38
Incorrect
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A 35-year-old ultra marathon runner becomes severely dehydrated and collapses. This patient most likely has:
Your Answer: Low water permeability of collecting duct tubular cells
Correct 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 39
Correct
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An ECG of a 30 year old woman revealed low voltage QRS complexes. This patient is most probably suffering from?
Your Answer: Pericardial effusion
Explanation:The QRS complex is associated with current that results in the contraction of both the ventricles. As ventricles have more muscle mass than the atria, they result in a greater deflection on the ECG. The normal duration of a QRS complex is 10s. A wide and deep Q wave depicts myocardial infarction. Abnormalities in the QRS complex maybe indicative of a bundle block, ventricular tachycardia or hypertrophy of the ventricles. Low voltage QRS complexes are characteristic of pericarditis or a pericardial effusion.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 40
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 41
Incorrect
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A 31 -year-old female patient had a blood gas done on presentation to the emergency department. She was found to have a metabolic acidosis and decreased anion gap. The most likely cause of these findings in this patient would be?
Your Answer: Uraemia
Correct Answer: Hypoalbuminemia
Explanation:A low anion gap might be caused by alterations in serum protein levels, primarily albumin (hypoalbuminemia), increased levels of calcium (hypercalcaemia) and magnesium (hypermagnesemia) or bromide and lithium intoxication. However, the commonest cause is hypoalbuminemia, thus if the albumin concentration falls, the anion gap will also be lower. The anion gap should be corrected upwards by 2.5 mmol/l for every 10g/l fall in the serum albumin.
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This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
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Question 42
Correct
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Intravenous diazepam was administered to a man who was brought to the emergency department with status epilepticus. He was administered 15 l/min oxygen via a reservoir bag mask. Blood investigations showed sodium = 140 mmol/l, potassium = 4 mmol/l and chloride = 98 mmol/l. His arterial blood gas analysis revealed pH 7.08, p(CO2)= 61.5 mmHg, p(O2) = 111 mmHg and standard bicarbonate = 17 mmol/l. This patient had:
Your Answer: Mixed acidosis
Explanation:Acidosis with high p(CO2) and low standard bicarbonate indicates mixed acidosis. Lower p(O2) is due to breathing of 70% oxygen. The prolonged seizures lead to lactic acidosis and the intravenous diazepam is responsible for the respiratory acidosis. Treatment includes airway manoeuvres and oxygen, assisted ventilation if needed, and treatment with fluids.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 43
Correct
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A surgeon trainee is assisting in an operation to ligate the ductus arteriosus. The consultant supervising explains that caution is required when placing a clamp on the ductus to avoid injury to an important structure immediately dorsal to it. To which structure is the consultant referring?
Your Answer: Left recurrent laryngeal nerve
Explanation:The left recurrent laryngeal nerve branches off the vagus and wraps around the aorta, posterior to the ductus arteriosus/ligamentum arteriosum from whence it courses superiorly to innervate the laryngeal muscles.
Accessory Hemiazygous vein is on the left side of the body draining the posterolateral chest wall and emptying blood into the azygos vein.
The left internal thoracic artery is branch of the left subclavian artery supplying blood to the anterior wall of the thorax.
Left phrenic nerve is lateral to the vagus nerve.
Thoracic duct: is behind the oesophagus, coursing between the aorta and the azygos vein in the posterior chest.
Right recurrent laryngeal nerve: loops around the right subclavian artery and is not in danger in this procedure.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 44
Incorrect
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A lad involved in a road traffic accident is rushed to casualty where physical examination reveals that he has limited extension of his right humerus. Which of the following nerves is most likely to have been injured?
Your Answer: Medial pectoral nerve
Correct Answer: Thoracodorsal nerve
Explanation:Extension of the humerus is a function of the latissimus dorsi. This muscle is supplied by the thoracodorsal nerve which is a branch of the posterior cord of the plexus whose fibres are derived from cranial nerves V, VI and VII.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 45
Correct
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The thyroid gland is a large ductless gland located in which part of the neck?
Your Answer: Visceral space
Explanation:The thyroid gland is an endocrine gland in the neck, consisting of two lobes connected by an isthmus. It is situated at the front and sides of the neck in the visceral space.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 46
Incorrect
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Myoglobin is released as a result of rhabdomyolysis from damaged skeletal muscles. What function do they perform in the muscle?
Your Answer: Is found in fast fibres only
Correct Answer: Acts like haemoglobin and binds with O2
Explanation:Myoglobin is a pigmented globular protein made up of 153 amino acids with a prosthetic group containing haem around which the apoprotein folds. It is the primary oxygen carrying protein of the muscles. The binding of oxygen to myoglobin is unaffected by the oxygen pressure as it has an instant tendency to bind given its hyperbolic oxygen curve. It releases oxygen at very low pO2 levels.
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This question is part of the following fields:
- General
- Physiology
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Question 47
Incorrect
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A glycogen storage disorder is characterised by increased liver glycogen with a normal structure and no increase in serum glucose after oral intake of a protein-rich diet. Deficiency of which of the following enzymes is responsible for this disorder?
Your Answer: UDPG–glycogen transglucosylase
Correct Answer: Glucose-6-phosphatase
Explanation:The most common glycogen storage disorder is von Gierke’s disease or glycogen storage disease type I. It results from a deficiency of enzyme glucose-6-phosphatase which affects the ability of liver to produce free glucose from glycogen and gluconeogenesis; leading to severe hypoglycaemia. There is also increased glycogen storage in the liver and kidneys causing enlargement and various problems in their functioning. The disease also causes lactic acidosis and hyperlipidaemia. The main treatment includes frequent or continuous feedings of corn-starch or other carbohydrates.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 48
Correct
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Which of the following factors will not affect the wound healing process in a young women who suffered serious burns to her chest and hands?
Your Answer: Vitamin A deficiency
Explanation:Healing can be sped-up or slowed down due to various reasons: 1. blood supply, 2. infection, 3. denervation, 4. collection of blood/hematoma, 5. mechanical stress, 6. foreign body, 7. techniques used during surgery and 8. dressing of the wound. Other systemic factors include 1. nutrition e.g. deficiency of zinc, vitamin C, protein deficiency, 2. metabolic status, 3. circulatory status and 4. hormonal influence
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This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
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Question 49
Incorrect
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A 45 -year-old female is recently diagnosed with breast cancer. She has a 8-cm-diameter mass in her left breast, with enlarged left axillary node. What is the most likely stage of her disease?
Your Answer: IIB
Correct Answer: IIIA
Explanation:Stage IIIA breast cancer is T0–2 N2 M0 or T3 N1-2 M0 disease. It describes invasive breast cancer in which either: the tumour is smaller than 5 cm in diameter and has spread to 4 to 9 axillary lymph nodes; or it is found through imaging studies or clinical exam to have spread to internal mammary nodes (near the breastbone found during imaging tests or a physical exam); or the tumour is larger than 5 cm and has spread to 1 to 9 axillary nodes, or to internal mammary nodes. In this stage, the cancer has not metastasized (spread to distant sites).
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 50
Correct
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During gastrectomy, the operating surgeon ligates the short gastric arteries along the greater curvature of the stomach. Where do the short gastric arteries branch from?
Your Answer: Splenic artery
Explanation:Short gastric arteries arise from the splenic artery at the end or from its terminal divisions. They are about 5 or 7 in number, passing from the left to the right in between the layers of the gastrosplenic ligament to be distributed along the greater curvature of the stomach.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 51
Incorrect
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A 25-year-old football player suffers severe head trauma during a game. Physical examination reveals a decerebrate posture and bilateral papilledema. A CT scan reveals marked diffuse cerebral oedema. This condition will be most severe in which component of the brain?
Your Answer: Meninges
Correct Answer: White matter
Explanation:The greatest amount of salt and water increase with cerebral oedema occurs within the white matter. Any swelling from oedema, haemorrhage or haematoma increases the intracranial pressure (ICP). As the ICP increases, the cerebral perfusion decreases and brain tissue can become ischaemic, even leading to brain death.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 52
Correct
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Where do the seminal vesicles lie?
Your Answer: Base of the bladder and rectum
Explanation:The seminal vesicles are two lobulated membranous pouches situated between the fundus of the bladder and rectum and act as a reservoir for the semen and secrete a fluid that is added to the seminal fluid. Each sac is pyramidal in shape but they all vary in size not only in different individuals but also in the same individuals. The anterior surface is in contact with the fundus of the bladder, extending from near the termination of the ureter to the base of the prostate. Each vesicle consist of single tube, which gives off several irregular caecal diverticula. These separate coils and the diverticula are connected by fibrous tissue.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 53
Correct
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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 54
Correct
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A 23-year-old woman decides to donate a kidney through a kidney chain. Which of the following indices would be expected to be decreased in the donor after full recovery from the operation?
Your Answer: Creatinine clearance
Explanation:Since medication to prevent rejection is so effective, donors do not need to be similar to their recipient. Most donated kidneys come from deceased donors; however, the utilisation of living donors is on the rise. Most problems encountered with live donation are associated with the donor. Firstly, there are the potentially harmful investigative procedures carried out in the assessment phase, the most hazardous being renal angiography, where there is cannulation of the artery and injection of a radio-opaque dye to determine the blood supply to the kidney. Secondly, there are the short-term risks of nephrectomy surgery. According to the literature, there is a mortality rate of between 1 in 1600 and 1 in 3000, but this is no more than is associated with any anaesthetic. In the initial postoperative period creatinine clearance may be decreased but this recovers fully over a few weeks to months. Long-term complications include prolonged wound pain.
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This question is part of the following fields:
- Physiology
- Renal
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Question 55
Correct
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Severe abdominal pain radiating to the back, along with increased serum amylase levels, is seen in which of the following conditions?
Your Answer: Pancreatitis
Explanation:The primary test for diagnosis and monitoring of pancreatitis is amylase. Increased plasma levels of amylase can be found in: salivary trauma (including anaesthetic intubation), mumps, pancreatitis and renal failure. However, a rise in the total amylase levels over 10 times the upper limit of normal (ULN) is suggestive of pancreatitis; 5–10 times the ULN may indicate ileus or duodenal disease or renal failure. Lower levels are commonly found in salivary gland disease.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 56
Correct
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A 78-year-old woman was brought to the emergency department with decreased consciousness, weakness and dehydration. Which serum electrolyte would most likely be low in this patient?
Your Answer: Na+
Explanation:Hyponatremia is a sodium level below 135 mEq/L. Signs and symptoms may include: nausea with vomiting, fatigue, headache or confusion, cramps or spasm, irritability and restlessness and severe cases may lead to seizures and comma.
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This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
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Question 57
Incorrect
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A 10-year-old boy was sent for an x-ray of the leg because he was complaining of pain and swelling. The x-ray showed the classic sign of Codman's triangle. What is the most likely diagnosis of this patient?
Your Answer: Chondrosarcoma
Correct Answer: Osteosarcoma
Explanation:Codman’s triangle is the triangular area of new subperiosteal bone that is created when a lesion, often a tumour, raises the periosteum away from the bone. The main causes for this sign are osteosarcoma, Ewing’s sarcoma, eumycetoma, and a subperiosteal abscess.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 58
Correct
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Which of the following conditions is likely to result in splenomegaly, hypochromic anaemia and hemochromatosis in a young male?
Your Answer: β-Thalassaemia
Explanation:Beta-thalassaemia is due to decreased production of β-polypeptide chains, with an autosomal inheritance pattern. Carrier patients (heterozygotes) are asymptomatic and have mild to moderate microcytic anaemia. This is known as thalassaemia minor. Homozygotes (β-thalassaemia major, or Cooley’s anaemia) develop severe anaemia and marrow hyperactivity. The disease presents at 1-2 years of age with severe anaemia and transfusional and absorptive iron overload. Patients also present with jaundice, leg ulcers, massive splenomegaly and cholelithiasis. The disease can also lead to splenic sequestration leading to faster destruction of transfused red blood cells. Increased marrow activity causes thickening of cranial bones. Involvement of long bones is also seen, which can cause pathological fractures and growth impairment. There is iron deposition in various organs, which can lead to heart failure or hepatic failure (leading to cirrhosis). Thalassaemias are suspected in presence of family history, or signs suggesting microcytic haemolytic anaemia. Further test and quantitative haemoglobin studies are useful. In beta-thalassaemia, there is an increase in serum bilirubin, iron and ferritin levels. There is severe anaemia, often with haemoglobin < 6 g/dl. There is an elevated red blood cell count, which are microcytic. Peripheral blood smear is diagnostic with nucleated erythroblasts, target cells, small pale red blood cells, and punctate basophilia.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 59
Correct
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Lung compliance is increased by:
Your Answer: Emphysema
Explanation:Lung compliance is increased by emphysema, acute asthma and increasing age and decreased by alveolar oedema, pulmonary hypertension, atelectasis and pulmonary fibrosis.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 60
Correct
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Which of the following is a likely consequence of severe diarrhoea?
Your Answer: A decrease in the sodium content of the body
Explanation:Diarrhoea can occur due to any of the numerous aetiologies, which include infectious, drug-induced, food related, surgical, inflammatory, transit-related or malabsorption. Four mechanisms have been implicated in diarrhoea: increased osmotic load, increased secretion, inflammation and decreased absorption time. Diarrhoea can result in fluid loss with consequent dehydration, electrolyte loss (Na+, K+, Mg2+, Cl–) and even vascular collapse. Loss of bicarbonate ions can lead to a metabolic acidosis.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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SESSION STATS - PERFORMANCE PER SPECIALTY
