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Question 1
Correct
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Which of these illnesses is most likely to precede Guillain-Barré syndrome?
Your Answer: Viral pneumonia
Explanation:Guillain–Barré syndrome (GBS) is characterized by a rapid-onset muscle weakness caused by the immune system damaging the peripheral nervous system. In about two-thirds of patients, the syndrome begins 5 days to 3 weeks after an infectious disease, surgery or vaccination. Infection is the trigger in over 50% of patients; common pathogens include Campylobacter jejuni, enteric viruses, herpesviruses (including cytomegalovirus and those causing infectious mononucleosis) and Mycoplasma species. The underlying mechanism involves an autoimmune disorder in which the body’s immune system mistakenly attacks the peripheral nerves and damages their myelin insulation, although the cause for this is still unknown.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 2
Incorrect
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A 55 year old man presented with a 4 day history of cough and fever. His sputum culture showed the presence of Strep pneumoniae. Which of the following substances produced by the inflammatory cells will result in effective clearance of this organism from the lung parenchyma?
Your Answer: Platelet-activating factor
Correct Answer: Hydrogen peroxide
Explanation:Hydrogen peroxide is produced by myeloperoxidase to form a potent oxidant that eliminates bacteria, but is not effective in chronic granulomatous diseases.
Platelet activating factor will lead to the activation, adhesion and aggregation of platelets but will not directly kill bacteria.
Prostaglandins cause vasodilation but do not activate neutrophils.
Kallikrein promotes formation of bradykinin that leads to vasodilation.
Leukreines increase vascular permeability.
Cytokines are communicating molecules between immune cells but directly will not kill bacteria.
Interleukins will regulate the immune response.
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This question is part of the following fields:
- Inflammation & Immunology; Respiratory
- Pathology
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Question 3
Correct
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Blood supply to the posterior compartment of the thigh is supplied by which artery?
Your Answer: Perforating
Explanation:There are usually 3 perforating arteries:
The first gives branches to the adductor brevis and magnus, biceps femoris and gluteus maximus and anastomoses with the inferior gluteal, medial and lateral femoral circumflex.
The second artery supplies the posterior femoral muscles and anastomose with the first and third perforating vessels.
The third supplies the posterior femoral muscles.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 4
Incorrect
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The gradual depolarization in-between action potentials in pacemaker tissue is a result of?
Your Answer: A gradual increase in inward Na+ (INa) channels current through fast Na+ channels
Correct Answer: A combination of gradual inactivation outward IK along with the presence of an inward ‘funny’ current (If) due to opening of channels permeable to both Na+ and K+ ions
Explanation:One of the characteristic features of the pacemaker cell is the generation of a gradual diastolic depolarization also called the pacemaker potential. In phase 0, the upstroke of the action potential caused by an increase in the Ca2+ conductance, an influx of calcium occurs and a positive membrane potential is generated. The next is phase 3 which is repolarization caused by increased K+ conductance as a result of outwards K+ current. Phase 4 is a slow depolarization which accounts for the pacemaker activity, caused by increased conductance of Na+, inwards Na+ current called IF. it is turned on by repolarization.
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This question is part of the following fields:
- General
- Physiology
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Question 5
Incorrect
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Below which level of the spinal cord will the inferior gluteal nerve be unaffected?
Your Answer: S1
Correct Answer: S3
Explanation:The inferior gluteal nerve arises from the dorsal divisions of the fifth lumbar and first and second sacral nerves. According to this fact any lesion at or below the S3 will not affect the inferior gluteal nerve.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 6
Incorrect
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Which of the following is a large artery that runs immediately posterior to the stomach?
Your Answer: Gastroduodenal
Correct Answer: Splenic
Explanation:The splenic artery is the large artery that would be found running off the posterior wall of the stomach. It is a branch of the coeliac trunk and sends off branches to the pancreas before reaching the spleen. The gastroduodenal artery on the other hand is found inferior to the stomach, posterior to the first portion of the duodenum. The left gastroepiploic artery runs from the left to the right of the greater curvature of the stomach. The common hepatic artery runs on the superior aspect of the lesser curvature of the stomach, and is a branch of the coeliac trunk. The superior mesenteric artery arises from the abdominal aorta just below the junction of the coeliac trunk.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 7
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 8
Incorrect
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A 36-year old gentleman with a history of cough for 4 weeks came to the hospital. Examination revealed multiple lymphadenopathy with splenomegaly. Investigations revealed haemoglobin 11 g/dl, haematocrit 32.4%, mean corpuscular volume (MCV) 93 fl, white blood cell count 63 × 109/l, and platelet count 39 × 109/l; along with characteristic Auer rods on peripheral blood smear. What is the likely diagnosis?
Your Answer: Hodgkin's lymphoma
Correct Answer: Acute myelogenous leukaemia (AML)
Explanation:AML, or acute myeloid leukaemia is the commonest acute leukaemia affecting adults. increasing in incidence with age. It is a malignancy of the myeloid line of white blood cells. It results in rapid proliferation of abnormal cells, which accumulate in the marrow. Interference with normal cell production leads to a drop in red blood cells, white blood cells and platelets. This causes symptoms such as tiredness, shortness of breath, tendency to bleed or bruise easily and recurrent infections. AML is known to progress quickly and can lead to death in weeks and months if not treated. Leukemic blasts of AML show presence of Auer rods. These are clumps of azurophilic granular material that form needles in the cytoplasm. Composed of fused lysosomes, these contain peroxidase, lysosomal enzymes and crystalline inclusions. Auer rods are classically present in myeloid blasts of M1, M2, M3 and M4 acute leukaemia. They also help to distinguish the preleukemia myelodysplastic syndromes.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 9
Correct
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A 70 year old women, died suddenly. She had a history of hypertension and aortic stenosis. On autopsy her heart weighed 550g. What is the most likely cause of this pathology?
Your Answer: Hypertrophy
Explanation:Due to increased pressure on the heart as a result of hypertension and aortic stenosis, the myocardial fibres hypertrophied to adapt to the increased pressure and to effectively circulate blood around the body. Hyperplasia could not occur, as myocardial fibres are stable cells and cannot divide further.
Fat does not deposit in the heart due to volume overload.
Myocardial oedema is not characteristic of a myocardial injury.
Metaplasia is a change in the type of epithelium.
Atrophy would result in a decreased heart size and inability to function.
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This question is part of the following fields:
- Cell Injury & Wound Healing; Cardiovascular
- Pathology
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Question 10
Correct
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A patient with Paget's disease of the bone is predisposed to developing which type of cancer?
Your Answer: Osteosarcoma
Explanation:Paget’s disease of bone (PDB) is a focal disorder of bone. It is presumed benign in nature and mediated by abnormal osteoclast function. However osteosarcomas may occur in <1% of patients with Paget's disease of the bone. Osteosarcomas are osteogenic in origin, and consistently arise in sites of pagetic bone. This is not to be confused with Paget's disease of the breast.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 11
Incorrect
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A 78-year-old diabetic man undergoes renal function tests. Which of the following substances will be the most accurate for measuring glomerular filtration rate (GFR)?
Your Answer: Urea
Correct Answer: Inulin
Explanation:Glomerular filtration rate (GFR) is the volume of fluid filtered from the renal glomerular capillaries into the Bowman’s capsule per unit time. Clinically, this is often measured to determine renal function. Inulin was originally used as it is not reabsorbed by the kidney after glomerular filtration, therefore its rate of excretion is directly proportional to the rate of filtration of water and solutes across the glomerular filter. However, in clinical practice, creatinine clearance is used to measure GFR. Creatinine is an endogenous molecule, synthesised in the body, that is freely filtered by the glomerulus (but also secreted by the renal tubules in very small amounts). Creatinine clearance exceeds GFR due to creatinine secretion, and is therefore a close approximation of the GFR.
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This question is part of the following fields:
- Physiology
- Renal
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Question 12
Incorrect
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Blood investigations of a patient with vitamin K deficiency revealed a prolonged prothrombin time. This coagulation abnormality is most probably due to:
Your Answer: Factor V deficiency
Correct Answer: Factor VII deficiency
Explanation:Factor VII deficiency is a bleeding disorder caused by a deficiency or reduced activity of clotting factor VII. It may be inherited or acquired at some point during life. Inherited factor VII deficiency is an autosomal recessive disorder caused by mutations of the F7 gene. Factor VII is vitamin K-dependent, as are Factors II, IX and X and therefore lack of this vitamin can cause the development of acquired factor VII deficiency. Other causes of acquired deficiency of this factor include liver disease, sepsis and warfarin therapy.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 13
Incorrect
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During strenuous exercise, what else occurs besides tachycardia?
Your Answer: No change to blood pressure
Correct Answer: Increased stroke volume
Explanation:During strenuous exercise there is an increase in:
– Heart rate, stroke volume and therefore cardiac output. (CO = HR x SV)
– Respiratory rate (hyperventilation) which will lead to a reduction in Paco2.
– Oxygen demand of skeletal muscle, therefore leading to a reduction in mixed venous blood oxygen concentration.
Renal blood flow is autoregulated, so renal blood flow is preserved and will tend to remain the same. Mean arterial blood pressure is a function of cardiac output and total peripheral resistance and will increase with exercise, mainly as a result of the increase in cardiac output that occurs.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 14
Correct
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A patient in the recovery ward after cardiac surgery is noticed to have a small effusion in the lowest extent of the pleural cavity, into which no lung tissue extends. What is the name of this part of the pleural cavity?
Your Answer: Costodiaphragmatic recess
Explanation:The costodiaphragmatic recess is the part of the pleural cavity where the costal pleura is in continuity with the diaphragmatic pleura. It forms the lowest extent of the pleural cavity.
Costomediastinal recess: a tiny recess that is anteriorly located, where the costal pleura becomes continuous with the mediastinal pleura.
The cupola is the pleural cavity that extends above the first rib.
The inferior mediastinum refers to the posterior, middle and anterior mediastinal divisions together.
The pulmonary ligament on the other hand, is a pleural fold that is situated beneath the root of the lung on the medial aspect of the lung.
Oblique pericardial sinus is not part of the pleural cavity.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 15
Correct
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A 27-year old lady is shot in the chest. The bullet enters superior to the upper edge of the clavicle. She had difficulty in breathing which is interpreted by the A&E physician as a likely indicator of a collapsed lung. If that is the case, what portion of the pleura is most likely to have been punctured?
Your Answer: Cupola
Explanation:The cupola is part of the pleura that extends above the first rib into the root of the lung. Most likely to injured in a stab above the level of the clavicle.
Costodiaphragmatic recess: the lowest extent of the pleural sac.
Pulmonary ligament: is a fold of pleura located below the root of the lung.
Mediastinal pleura: part of the pleura that lines the mediastinal cavity.
Hilar reflection is the part of the pleura where the visceral pleura of the lung reflects to become continuous with the parietal pleura.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 16
Correct
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Identify which of the following muscles acts on two joints?
Your Answer: Sartorius
Explanation:The sartorius muscle, the longest muscle in the body, is one of the two jointed or biarticular muscles. It originates from the anterior superior iliac spine and part of the notch between the anterior superior iliac spine and anterior inferior iliac spine and crosses both the hip joint and the knee joint. At the hip joint the sartorius flexes and rotates the thigh at the hip joint and flexes 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 17
Correct
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Which organ is responsible for the secretion of enzymes that aid in digestion of complex starches?
Your Answer: Pancreas
Explanation:α-amylase is secreted by the pancreas, which is responsible for hydrolysis of starch, glycogen and other carbohydrates into simpler compounds.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 18
Correct
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An abnormal opening of the urethra on the under surface of the penis (ventral surface) is known as:
Your Answer: Hypospadias
Explanation:Hypospadias is the condition where the urethra opens along the underside or ventral aspect of penile shaft. First-degree hypospadias is seen in 50-75% cases, where the urethra open on the glans penis. Second-degree hypospadias is seen in 20% cases where the urethra opens on the shaft, and third-degree in 30% cases with the urethra opening on the perineum. The severe cases are usually associated with undescended testis (cryptorchidism) or chordee, where the penis is tethered downwards and not completely separated from the perineum.
It is a common male genital birth defect but varying incidences are noted in different countries. There is no obvious inheritance pattern noted. No exact cause has been determined, however several hypotheses include poor response to androgen, or interference by environmental factors.
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This question is part of the following fields:
- Pathology
- Urology
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Question 19
Correct
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Which of the following has the least malignant potential?
Your Answer: Hyperplastic polyp
Explanation:Non-neoplastic (non-adenomatous) colonic polyps include hyperplastic polyps, hamartomas, juvenile polyps, pseudopolyps, lipomas, leiomyomas and others.
An autosomal dominant condition, Peutz–Jeghers syndrome is a disease that is characterized by multiple hamartomatous polyps in the stomach, small bowel and colon. Symptoms of this syndrome include hyperpigmentation of the skin and mucous membranes, especially of the lips and gums.
Juvenile polyps develop in children, and once they outgrow their blood supply, they autoamputate around puberty. In cases of uncontrolled bleeding or intussusception, treatment is needed.
Inflammatory polyps and pseudopolyps occur in chronic ulcerative colitis and Crohn’s disease. There is an increased risk of cancer with multiple juvenile polyps (not with sporadic polyps).
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This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
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Question 20
Correct
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The following branch of the aorta is unpaired:
Your Answer: Coeliac artery
Explanation:Branches that stem from the abdominal aorta can be divided into three: the visceral branches, parietal branches and terminal branches. Of the visceral branches, the suprarenal, renal, testicular and ovarian arteries are paired while the coeliac artery and superior and inferior mesenteric arteries are unpaired. Of the parietal branches the inferior phrenic and lumbar arteries are paired while the middle sacral artery is unpaired. The terminal branches i.e. the common iliac arteries are paired.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 21
Incorrect
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Which of the following is true regarding factor XI?
Your Answer: Activates factor X
Correct Answer: Deficiency causes haemophilia C
Explanation:Factor XI is also known as plasma thromboplastin and is one of the enzymes of the coagulation cascade. It is produced in the liver and is a serine protease. It is activated by factor XIIa, thrombin and by itself. Deficiency of factor XI causes the rare type of haemophilia C. Low levels of factor XI also occur in other disease states, including Noonan syndrome. High levels of factor XI have been seen in thrombosis.
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This question is part of the following fields:
- General
- Physiology
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Question 22
Incorrect
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The passage of leukocytes through the wall of the blood vessels is best described by which of the following terms?
Your Answer: Chemotaxis
Correct Answer: Diapedesis
Explanation:The steps involved in leukocyte arrival and function are:
1. margination: cells migrate from the centre to the periphery of the vessel
2. rolling: selectins are upregulated on the vessel walls
3. adhesion: upregulation of the adhesion molecules ICAM and VCAM on the endothelium interact with integrins on the leukocytes, interaction of these results in adhesion
4. diapedesis and chemotaxis: diapedesis is the transmigration of the leukocyte across the endothelium of the capillary and towards a chemotactic product
5. phagocytosis: engulfing the offending substance/cell.
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This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
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Question 23
Incorrect
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A 65-year old man, known with Type 2 diabetes and chronic renal failure, is likely to eventually present with which of the following conditions?
Your Answer: Cushing syndrome
Correct Answer: Secondary hyperparathyroidism
Explanation:When the parathyroid glands secrete excess parathyroid hormone (PTH) in response to hypocalcaemia, it is known as Secondary hyperparathyroidism and is often seen in patients with renal failure. In chronic renal failure, the kidneys fail to excrete adequate phosphorus and also fail to convert enough vitamin D to its active form. This leads to formation of insoluble calcium phosphate in the body which ultimately causes hypocalcaemia. The glands then undergo hyperplasia and hypertrophy leading to secondary hyperparathyroidism. Symptoms include bone and joint pains, along with limb deformities. The raised PTH also results in pleiotropic effects on blood, the immune system and nervous system.
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This question is part of the following fields:
- Endocrine
- Pathology
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Question 24
Incorrect
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During clinic, a medical student conducts a physical examination on a teenage boy with a lump in the inguinal region. The lump is protruding from the superficial inguinal ring. The student correctly concluded that it was:
Your Answer: Definitely an indirect inguinal hernia
Correct Answer: Either a direct or an indirect inguinal hernia
Explanation:It is not possible to tell if an inguinal hernia is direct or indirect just by palpating it. Despite the fact that indirect inguinal hernias commonly come out of the superficial inguinal ring to enter the scrotum, direct inguinal hernia might still do this.
Femoral hernia goes through the femoral ring into the femoral canal (has nothing to do with the superficial inguinal ring).
Superficial inguinal lymph nodes lie in the superficial fascia parallel to the inguinal ligament; it would therefore feel more superficial and would not be mistaken for a hernia protruding through the inguinal ring.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 25
Incorrect
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After a total colectomy and ileotomy, a 50-year old diabetic man who was a known case of diabetic nephropathy had persistent metabolic acidosis. The patient appeared well perfused, with normal vital signs and normal fluid balance. Investigations revealed:
Sodium = 132 mmol/l
Potassium = 6.6 mmol/l
Creatinine = 185 μmol/l (2.16 mg/dl)
Chloride = 109 μmol/l
8am cortisol = 500 nmol/l (18 μg/dl)
pH = 7.29, p(CO2) = 27 mmHg
p(O2) = 107 mmHg
standard bicarbonate = 12 mmol/l.
What is the likely causes of his acidosis?Your Answer: Ketoacidosis
Correct Answer: Renal tubular acidosis
Explanation:Acidosis here is due to low bicarbonate. The low p(CO2) is seen in compensation. The anion gap is normal, ruling out intra-abdominal ischaemia (which leads to metabolic acidosis). If it was a gastrointestinal aetiology, low potassium would be seen. The history of diabetic nephropathy predisposes to renal tubular acidosis. Type 4 (hyporeninaemic hypoaldosteronism) is associated with high potassium and is found in diabetic and hypertensive renal disease.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 26
Correct
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Which foramen contains the vertebral artery?
Your Answer: Foramen magnum
Explanation:The foramen magnum is found in the most inferior part of the posterior cranial fossa. It is traversed by vital structures including the medulla oblongata. Its contents include the following: medulla oblongata, meninges, spinal root of the accessory nerve, vertebral arteries, anterior and posterior spinal arteries, tectorial membrane and alar ligaments.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 27
Incorrect
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A 20-year old college student was diagnosed with meningitis that had developed due to an acute cavernous sinus thrombosis from an ear infection. Which of the following superficial venous routes is the usual path that an infected blood clot takes to reach the cavernous sinus?
Your Answer: Posterior cerebellar vein
Correct Answer: Facial vein
Explanation:The facial vein is the usual communication between the cavernous sinus and the pterygoid sinus. It is through this vein that an infected clot can travel to the cavernous sinus and cause infection. The pterygoid plexus is a venous plexus that is situated between the temporalis muscle and lateral pterygoid muscle, and partly between the two pterygoid muscles. The pterygoid plexus is connected to the facial vein by the deep facial vein. This connection is what makes this area where this sinus and the facial vein are located a danger zone. The danger zone or triangle of the face is the area from the corners of the mouth to the nose bridge. The sinus connection in this area makes it possible for infection to reach the cavernous sinus and at times cause meningitis.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 28
Incorrect
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The transmembrane proteins responsible for resting membrane potential of vascular smooth muscle cells was blocked by a drug. Which of the following transmembrane proteins were blocked by this drug?
Your Answer: Na+/K+ pump
Correct Answer: K+ channels
Explanation:The resting membrane potential is due to selective permeability of the membrane to potassium ions. The Na/K pump is responsible for the generation of a gradient across the membrane and it is due to the inherent ability of the K channels to allow diffusion back into the nerve at rest which charges the cells. In reality, the resting membrane potential is more positive because of small contributions by Na+ channels, Cl− channels and non-selective cation channels.
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This question is part of the following fields:
- General
- Physiology
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Question 29
Incorrect
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Which lymph nodes are likely to be enlarged in a patient who has malignant growth involving the anus?
Your Answer: Pararectal
Correct 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 30
Incorrect
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A 55-year old gentleman presented to the doctor with worsening dysphagia for both solids and liquids over 6 months. This was associated with regurgitation of undigested food and occasional chest pain. Barium swallow revealed distal oesophageal dilatation with lack of peristalsis in the distal two-third oesophagus. The likely diagnosis is:
Your Answer: Diffuse oesophageal spasm
Correct Answer: Achalasia
Explanation:Achalasia is an oesophageal motility disorder where inappropriate contractions in the oesophagus lead to reduced peristalsis and failure of the lower oesophageal sphincter to relax properly in response to swallowing. Classical triad of symptoms include dysphagia to fluids followed by solids, chest pain and regurgitation of undigested food. Other symptoms include belching, hiccups, weight loss and cough. Diagnosis is by:
– X-ray with a barium swallow or oesophagography : narrowing at the gastroesophageal junction (‘bird/parrot beak’ or ‘rat tail’ appearance) and various degrees of mega-oesophagus (oesophageal dilatation) as the oesophagus is gradually stretched by retained food. Effectiveness of treatment can be measured with a 5-minute timed barium swallow.
– Manometry – probe measures the pressure waves in different parts of oesophagus and stomach while swallowing.
– Endoscopy
– CT scan to exclude other causes like malignancy
– Pathological examination showing defect in the nerves which control oesophageal motility (myenteric plexus).
In Chagas disease, there is destruction of ganglion cells by Trypanosoma cruzi.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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SESSION STATS - PERFORMANCE PER SPECIALTY
