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Question 1
Incorrect
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A 79-year-old has been bedridden for 2 months after suffering from a stroke. She suddenly developed shortness of breath and chest pain, and was diagnosed with a pulmonary embolism. Which of the following is most likely to increase in this case?
Your Answer: Arterial CO2
Correct Answer: Ventilation/perfusion ratio
Explanation:Pulmonary embolism (PE) is a blockage of an artery in the lungs by an embolus that has travelled from elsewhere in the body through the bloodstream. The change in cardiopulmonary function is proportional to the extent of the obstruction, which varies with the size and number of emboli obstructing the pulmonary arteries. The resulting physiological changes may include pulmonary hypertension with right ventricular failure and shock, dyspnoea with tachypnoea and hyperventilation, arterial hypoxaemia and pulmonary infarction. Consequent alveolar hyperventilation is manifested by a lowered pa(CO2). After occlusion of the pulmonary artery, areas of the lung are ventilated but not perfused, resulting in wasted ventilation with an increased ventilation/perfusion ratio – the physiological hallmark of PE – contributing to a further hyperventilatory state. The risk of blood clots is increased by cancer, prolonged bed rest, smoking, stroke, certain genetic conditions, oestrogen-based medication, pregnancy, obesity, and post surgery.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 2
Correct
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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: 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 3
Correct
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A 49-year-old man, smoker, complains of a persisting and worsening cough over the past few months. He also has noted blood in his sputum. The patient has no other major health conditions. Which of the following investigative procedures should be done first?
Your Answer: Sputum cytology
Explanation:Sputum cytology is a diagnostic test used for the examination of sputum under a microscope to determine if abnormal cells are present. It may be used as the first diagnostic procedure to help detect a suspected lung cancer or certain non-cancerous lung conditions.
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This question is part of the following fields:
- Pathology
- Respiratory
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Question 4
Incorrect
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What is the likely diagnosis in a 55-year old man presenting with jaundice, weight loss, pale coloured stools and elevated alkaline phosphatase?
Your Answer: Gilbert’s syndrome
Correct Answer: Pancreatic carcinoma
Explanation:Increased alkaline phosphatase is indicative of cholestasis, with a 4x or greater increase seen 1-2 days after biliary obstruction. Its level can remain elevated several days after the obstruction is resolved due to the long half life (7 days). Increase up to three times the normal level can be seen in hepatitis, cirrhosis, space-occupying lesions and infiltrative disorders. Raised alkaline phosphatase with other liver function tests being normal can occur in focal hepatic lesions like abscesses or tumours, or in partial/intermittent biliary obstruction. However, alkaline phosphatase has several isoenzymes, which originate in different organs, particularly bone. An isolated rise can also be seen in malignancies (bronchogenic carcinoma, Hodgkin’s lymphoma), post-fatty meals (from the small intestine), in pregnancy (from the placenta), in growing children (from bone growth) and in chronic renal failure (from intestine and bone). One can differentiate between hepatic and non-hepatic cause by measurement of enzymes specific to the liver e.g. gamma-glutamyl transferase (GGT).
In an elderly, asymptomatic patient, isolated rise of alkaline phosphatase usually points to bone disease (like Paget’s disease). Presence of other symptoms such as jaundice, pale stools, weight loss suggests obstructive jaundice, most probably due to pancreatic carcinoma.
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This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
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Question 5
Incorrect
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Evaluation of a 60-year old gentleman, who has been a coal miner all his life and is suspected to have pulmonary fibrosis reveals the following: FEV1 of 75% (normal > 65%), arterial oxygen saturation 92%, alveolar ventilation 6000 ml/min at a tidal volume of 600 ml and a breathing rate of 12 breaths/min. There are also pathological changes in lung compliance and residual volume. Calculate his anatomical dead space.
Your Answer: 120 ml
Correct Answer: 100 ml
Explanation:Dead space refers to inhaled air that does not take part in gas exchange. Because of this dead space, taking deep breaths slowly is more effective for gas exchange than taking quick, shallow breaths where a large proportion is dead space. Use of a snorkel by a diver increases the dead space marginally. Anatomical dead space refers to the gas in conducting areas such as mouth and trachea, and is roughly 150 ml (2.2 ml/kg body weight). This corresponds to a third of the tidal volume (400-500 ml). It can be measured by Fowler’s method, a nitrogen wash-out technique. It is posture-dependent and increases with increase in tidal volume. Physiological dead space is equal to the anatomical dead space plus the alveolar dead space, where alveolar dead space is the area in the alveoli where no effective exchange takes place due to poor blood flow in capillaries. This physiological dead space is very small normally (< 5 ml) but can increase in lung diseases. Physiological dead space can be measured by Bohr’s method. Total ventilation per minute (minute ventilation) is given by the product of tidal volume and the breathing rate. Here, the total ventilation is 600 ml times 12 breaths/min = 7200 ml/min. The problem mentions alveolar ventilation to be 6000 ml/min. Thus, the difference between the alveolar ventilation and total ventilation is 7200 – 6000 ml/min = 1200 ml/min, or 100 ml per breath at 12 breaths per min. This 100 ml is the dead space volume.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 6
Incorrect
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A 28 years old women presents with a history of chronic cough with fever for the past 2 months. A chest x ray revealed a diffuse bilateral reticulonodular pattern. A transbronchial biopsy was performed and histological examination showed focal areas of inflammation with epithelioid macrophages, Langhans cells and lymphocytes. Which of the immune reaction is responsible for this?
Your Answer: Type II hypersensitivity
Correct Answer: Type IV hypersensitivity
Explanation:A reactivated tuberculosis with granuloma formation is characteristic of type IV reaction. It is also called a delayed type of hypersensitivity reaction and takes around 2-8 days to deliver. It is a cell mediated response with the involvement of CD8 and CD4 cells and the release of IL-1 from macrophages that further activate these CD cells.
Granulomatous reactions are mostly cell-mediated.
Type I reactions are allergic and anaphylactic reactions and type II are complement-mediated immune reactions.
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This question is part of the following fields:
- Inflammation & Immunology; Respiratory
- Pathology
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Question 7
Correct
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Which of the following morphological features is most characteristic of hyaline degeneration?
Your Answer: Homogeneous, ground-glass, pink-staining appearance of cells
Explanation:The characteristic morphological features of hyaline degeneration is ground-glass, pinking staining cytoplasm with an intact cell membrane. The accumulation of lipids, calcium salts, lipofuscin and an amorphous cytoplasm with an intact cell membrane are all characteristically found in different situations.
Pyknotic nucleus and orphan Annie eye nucleus are not seen in hyaline degeneration.
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This question is part of the following fields:
- Cell Injury & Wound Healing
- 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
Incorrect
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An enlarged lymph node which shows well-defined, prominent paracortical follicles with germinal centres is most likely from which of the following patients?
Your Answer: A 16-year old boy with fever, weight loss and night sweats
Correct Answer: A 5-year-old boy with a sore throat and runny nose
Explanation:Lymphadenopathy is common in children and is usually reactive in nature. The description fits that of a benign, reactive lymph node.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 10
Correct
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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 11
Incorrect
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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: Sickle cell anaemia
Correct 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 12
Incorrect
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During a normal respiratory exhalation, what is the recoil alveolar pressure?
Your Answer: –10 cmH2O
Correct Answer: +10 cmH2O
Explanation:To determine compliance of the respiratory system, changes in transmural pressures (in and out) immediately across the lung or chest cage (or both) are measured simultaneously with changes in lung or thoracic cavity volume. Changes in lung or thoracic cage volume are determined using a spirometer with transmural pressures measured by pressure transducers. For the lung alone, transmural pressure is calculated as the difference between alveolar (pA; inside) and intrapleural (ppl; outside) pressure. To calculate chest cage compliance, transmural pressure is ppl (inside) minus atmospheric pressure (pB; outside). For the combined lung–chest cage, transmural pressure or transpulmonary pressure is computed as pA – pB. pA pressure is determined by having the subject deeply inhale a measured volume of air from a spirometer. Under physiological conditions the transpulmonary or recoil pressure is always positive; intrapleural pressure is always negative and relatively large, while alveolar pressure moves from slightly negative to slightly positive as a person breathes.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 13
Incorrect
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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: Wilson’s disease
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 14
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: Ischaemic bowel
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 15
Incorrect
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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: 3500 ml/min
Correct 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 16
Incorrect
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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 17
Incorrect
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A 50-year old gentleman who was admitted for elective surgery was found to have haemoglobin 9.5 g/dl, white blood cell count of 1.4 × 109/l and a mean corpuscular volume (MCV) of 134 fl. Which of the following is the likely finding on his peripheral blood smear?
Your Answer: Blasts
Correct Answer: Hypersegmented neutrophils
Explanation:The likely diagnosis is megaloblastic anaemia, which also shows the presence of hypersegmented neutrophils.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 18
Incorrect
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Which condition presents with a positive urine dipstick test for blood, but no blood cells on urine microscopy?
Your Answer: Post-streptococcal glomerulonephritis
Correct Answer: Myoglobinuria
Explanation:Myoglobinuria, or presence of myoglobulin in the urine is seen due to rhabdomyolysis (muscle destruction). Common causes of rhabdomyolysis include trauma, electrical injuries, burns, venom and drugs. Damaged muscle leads to release of myoglobin in the blood. Ideally, the released myoglobin gets filtered and excreted by the kidneys. However, excess myoglobin can occlude the renal filtration system leading to acute tubular necrosis and acute renal dysfunction.
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This question is part of the following fields:
- Pathology
- Renal
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Question 19
Correct
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Which cells are most commonly seen in a granulomatous lesion that suggests an underlying chronic inflammation?
Your Answer: Lymphocytes
Explanation:Lymphocytes and monocytes are commonly and characteristically recognised in a case of chronic inflammation.
Eosinophils and neutrophils are seen with acute inflammation.
Mast cells release histamine in early inflammation.
Basophils are seen with allergies.
Plasma cells are seen with viral infection.
Platelets are not characteristic of any type of inflammation.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 20
Incorrect
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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: Renal artery thrombosis
Correct 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 21
Incorrect
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A 40-year old woman presents with tightening of the skin over her fingers which makes movement of her fingers difficult.. She also gives a history of her fingers turning blue on exposure to low temperatures. She admits to gradual weight loss. Investigations reveal negative rheumatoid factor, negative antinuclear antibody and a positive anticentromere body. Which of the following conditions is she likely to have?
Your Answer: Gastric cancer
Correct Answer: Oesophageal stricture
Explanation:Scleroderma is a connective tissue disorder that ranges in severity and progression. The disease could show generalised skin thickening with rapid, fatal, visceral involvement; or only cutaneous involvement (typically fingers and face). The slow progressive form is also known as ‘limited cutaneous scleroderma’ or CREST syndrome (calcinosis cutis, Raynaud’s phenomenon, (o)oesophageal dysmotility, sclerodactyly, and telangiectasia).
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This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
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Question 22
Incorrect
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Gram positive bacteria differ from gram negative bacteria due to the presence of which of the following structures?
Your Answer: Endospore
Correct Answer: Outer membrane
Explanation:The reason bacteria are either Gram-positive or Gram-negative is due to the structure of their cell envelope (the cell envelope is defined as the cell membrane and cell wall plus an outer membrane, if one is present.) Gram-positive bacteria, for example, retain the crystal violet due to the amount of peptidoglycan in the cell wall. It can be said therefore that the Gram-stain procedure separates bacteria into two broad categories based on structural differences in the cell envelope.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 23
Incorrect
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Where do the cells belonging to the mononuclear phagocyte system originate?
Your Answer: Lymph nodes
Correct Answer: Bone marrow
Explanation:The macrophage originates from a committed bone marrow stem cell. It is called the pluripotent hematopoietic stem cell. This differentiates into a monoblast and then into a promonocyte and finally matures into a monocyte. When called upon they leave the bone marrow and enter into the circulation. Upon entering the tissue they transform into macrophages. Tissue macrophages include: Kupffer cells (liver), alveolar macrophages (lung), osteoclasts (bone), Langerhans cells (skin), microglial cells (central nervous system), and possibly the dendritic immunocytes of the dermis, spleen and lymph nodes.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 24
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 25
Incorrect
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Mallory bodies are characteristic of which of the following conditions?
Your Answer: Hepatitis B
Correct Answer: Alcoholic hepatitis
Explanation:Mallory bodies (or ‘alcoholic hyaline’) are inclusion bodies in the cytoplasm of liver cells, seen in patients of alcoholic hepatitis; and also in Wilson’s disease. These pathological bodies are made of intermediate keratin filament proteins that are ubiquinated or bound by proteins like heat chock protein. Being highly eosinophilic, they appear pink on haematoxylin and eosin staining.
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This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
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Question 26
Incorrect
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A 40-year old lady with a flail chest due to trauma was breathing with the help of a mechanical ventilator in the ICU, and was heavily sedated on muscle relaxants. Due to sudden power failure, a nurse began to hand-ventilate the patient with a Ambu bag. What change will occur in the following parameters: (Arterial p(CO2), pH) in the intervening period between power failure and hand ventilation?
Your Answer: Decrease, Decrease
Correct Answer: Increase, Decrease
Explanation: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. Respiratory acidosis can be acute or chronic. In acute respiratory acidosis, the p(CO2) is raised above the upper limit of normal (over 45 mm Hg) with 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). The given problem represents acute respiratory acidosis and thus, will show a increase in arterial p(CO2) and decrease in pH.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 27
Correct
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After finding elevated PSA levels, a 69-year-old man undergoes a needle biopsy and is diagnosed with prostatic cancer. What is the stage of this primary tumour?
Your Answer: T1c
Explanation:The AJCC uses a TNM system to stage prostatic cancer, with categories for the primary tumour, regional lymph nodes and distant metastases:
TX: cannot evaluate the primary tumour T0: no evidence of tumour
T1: tumour present, but not detectable clinically or with imaging T1a: tumour was incidentally found in less than 5% of prostate tissue resected (for other reasons)
T1b: tumour was incidentally found in more than 5% of prostate tissue resected
T1c: tumour was found in a needle biopsy performed due to an elevated serum prostate-specific antigen
T2: the tumour can be felt (palpated) on examination, but has not spread outside the prostate
T2a: the tumour is in half or less than half of one of the prostate gland’s two lobes
T2b: the tumour is in more than half of one lobe, but not both
T2c: the tumour is in both lobes
T3: the tumour has spread through the prostatic capsule (if it is only part-way through, it is still T2)
T3a: the tumour has spread through the capsule on one or both sides
T3b: the tumour has invaded one or both seminal vesicles
T4: the tumour has invaded other nearby structures.
In this case, the tumour has a T1c stage.
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This question is part of the following fields:
- Pathology
- Urology
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Question 28
Incorrect
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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: Epstein–Barr virus infection
Correct 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 29
Incorrect
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Normally, the O2 transfer in the lungs from alveolar to capillary is perfusion-limited. In which of the following situations does it become a diffusion-limited process?
Your Answer: Increased ventilatory rate
Correct Answer: Pulmonary oedema
Explanation:Normally, the transfer of oxygen from air spaces to blood takes place across the alveolar-capillary membrane by simple diffusion and depends entirely on the amount of blood flow (perfusion-limited process). Diseases that affect this diffusion will transform the normal process to a diffusion limited process. Thus, the diseases which cause a thickened barrier (such as pulmonary oedema due to increased extravascular lung water or asbestosis) will limit the diffusion of oxygen. Chronic obstructive lung diseases will have little effect on diffusion. Inhaling hyperbaric gas mixtures might overcome the diffusion limitation in patients with mild asbestosis or interstitial oedema, by increasing the driving force. Strenuous (not mild) exercise might also favour diffusion limitation and decrease passage time. Increasing the rate of ventilation will not have this affect but will only maintain a high oxygen gradient from air to blood.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 30
Incorrect
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Ventricular filling follows a delay caused by?
Your Answer: Bundle branches
Correct Answer: AV node
Explanation:The AV node is a conducting tissue found between the atria and the ventricles of the heart. It conducts electrical signal from the atria to the ventricles and acts a delaying mechanism preventing the atria and the ventricles from contracting at the same time. This decremental conduction prevents premature ventricular contraction in cases such as atrial fibrillation. A delay in the AV node is the reason for the PR segment seen on the ECG. In certain types of supraventricular tachycardia, a person could have two AV nodes; this will cause a loop in electrical current and uncontrollably rapid heart beat. When this electricity catches up with itself, it will dissipate and return to a normal heart rate.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 31
Incorrect
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A 7-year-old boys undergoes a testicular biopsy after a tumour is found in his right testis. Elements similar to hair and teeth are found in it. What kind of tumour is this?
Your Answer: Yolk sac carcinoma
Correct Answer: Teratoma
Explanation:A teratoma is a tumour containing tissue elements that are similar to normal derivatives of more than one germ layer. They usually contain skin, hair, teeth and bone tissue and are more common in children, behaving as a benign tumour. After puberty, they are regarded as malignant and can metastasise.
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This question is part of the following fields:
- Pathology
- Urology
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Question 32
Correct
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A 24 year old mother is breastfeeding her first child. Which of the following cellular adaptations occurred in her breast tissue to allow her to do this?
Your Answer: Lobular hyperplasia
Explanation:Under the influence of oestrogen in pregnancy, there is an increase in the number of lobules which will facilitate lactation.
Steatocytes occur due to loss of weight and nutritional deficit.
Metaplasia is a normal physiological process which is due to a change in normal epithelium with another type.
Lobular atrophy will result in a decreased capacity to provide milk.
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This question is part of the following fields:
- Cell Injury & Wound Healing; Female Health
- Pathology
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Question 33
Incorrect
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Increased resistance to flow of blood in cerebral vessels is most likely seen in:
Your Answer: Epileptic seizure
Correct Answer: Elevation in systemic arterial pressure from 100 to 130 mmHg
Explanation:Constant cerebral blood flow is maintained by autoregulation in the brain, which causes an increase in local vascular resistance to offset an increase in blood pressure. There will be an increase in cerebral blood flow (and decrease in resistance to cerebral blood flow) with a decrease in arterial oxygen or an increase in arterial CO2. Similarly, a decrease in viscosity will also increase the blood flow. Due to increased brain metabolism and activity during a seizure, there will also be an increase in the cerebral blood flow.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 34
Incorrect
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Elevated mean corpuscular volume with hypersegmented neutrophils and low reticulocyte index is seen in on the blood count of a middle-aged lady about to undergo elective surgery. On enquiry, she mentions feeling tired for a few months. Which of the following investigations should be carried out in her to reach a diagnosis?
Your Answer: Serum ferritin
Correct Answer: Serum vitamin B12 and folate
Explanation:Elevated levels of MCV indicates megaloblastic anaemia, which are associated with hypersegmented neutrophils. Likely causes include vitamin B12 or folate deficiency. Megaloblastic anaemia results from defective synthesis of DNA. As RNA production continues, the cells enlarge with a large nucleus. The cytoplasmic maturity becomes greater than nuclear maturity. Megaloblasts are produced initially in the marrow, before blood. Dyspoiesis makes erythropoiesis ineffective, causing direct hyperbilirubinemia and hyperuricemia. As all cell lines are affected, reticulocytopenia, thrombocytopenia and leukopenia develop. Large, oval blood cells (macro-ovalocytes) are released in the circulation, along with presence of hypersegmented neutrophils.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 35
Incorrect
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A chloride sweat test was performed on a 13-year-old boy. Results indicated a high likelihood of cystic fibrosis. This diagnosis is associated with a higher risk of developing which of the following?
Your Answer: Pneumocystis carinii pneumonia
Correct Answer: Bronchiectasis
Explanation:Cystic fibrosis is a life-threatening disorder that causes the build up of thick mucus in the lungs, digestive tract, and other areas of the body. It is a hereditary autosomal-recessive disease caused by mutations of the CFTR gene. Cystic fibrosis eventually results in bronchiectasis which is defined as a permanent dilatation and obstruction of bronchi or bronchioles.
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This question is part of the following fields:
- Pathology
- Respiratory
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Question 36
Incorrect
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Which of the following is an anion?
Your Answer: Potassium
Correct Answer: Phosphate
Explanation:Cations: sodium, magnesium, calcium and potassium
Anions: chloride, phosphate, bicarbonate, lactate, sulphate and albumin
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 37
Correct
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A 35-year-old woman is in a comatose state following a traumatic head injury, and is receiving intravenous (IV) antibiotics and IV fluids containing saline and 5% dextrose. A serum biochemistry analysis is performed five days later which shows a low serum potassium level. This is most likely to be due to:
Your Answer: Nothing per oral regimen
Explanation:In this patient the cause for hypokalaemia is insufficient consumption of potassium as she is nil-per mouth with no intravenous supplementation. Parenteral nutrition has been used for comatose patients, although enteral feeding is usually preferable, and less prone to complications.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 38
Incorrect
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An amateur body-builder complains of increasing pain in his right shoulder after a few days of intense training. A surgeon aspirates clear fluid from his subdeltoid region. What's the most likely diagnosis?
Your Answer: Tenosynovitis
Correct Answer: Bursitis
Explanation:Bursae are potential cavities that contain synovial fluid, found in areas where friction occurs. Their function is to minimise friction and facilitate movement. Bursitis is the inflammation of one or more bursae, and they can occur in the shoulder, elbow, knee, ischium, amongst other joints. Acute bursitis can appear after strenuous exercise or activity, and chronic bursitis can develop following previous bursitis or trauma. Acute bursitis causes pain, tenderness, and swelling.
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This question is part of the following fields:
- Orthopaedics
- Pathology
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Question 39
Incorrect
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A young girl who presented with a clinical picture of type I hypersensitivity reaction with eosinophilia is most likely to have?
Your Answer: Spirochetes
Correct Answer: Liver flukes
Explanation:Usually a parasitic infection will be associated with a type I hypersensitivity reaction.
Amyloid deposition will not cause an immune reaction.
Organic dust will lead to a type III hypersensitivity reaction.
Cell mediated as well as humoral immune mechanism play a part in syphilis, but they are do not specifically cause a type I reaction.
Malaria is cause by plasmodium and is not cause of a hypersensitivity reaction.
Atopic dermatitis will not be accompanied by eosinophilia.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 40
Incorrect
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Glucose is not secreted by the kidneys, and is filtered without a limit. What is the transport maximum for glucose?
Your Answer:
Correct Answer: 300 mg/dl
Explanation:Transport maximum (or Tm) refers to the point at which increases in concentration do not result in an increase in movement of a substance across a membrane. Glucose is not secreted, thus excretion = filtration – reabsorption. Both filtration and reabsorption are directly proportional to the concentration of glucose in the plasma. However, reabsorption has a transport maximum of about 300 mg/dl in healthy nephrons, while filtration has effectively no limit (within reasonable physiological ranges). So, if the concentration rises above 300 mg/dl, the body cannot retain all the glucose, leading to glucosuria. Glucosuria 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:
- Physiology
- Renal
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Question 41
Incorrect
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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:
Correct 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 42
Incorrect
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A 40-year old lady presented to the hospital with fever and mental confusion for 1 week. On examination, she was found to have multiple petechiae all over her skin and mucosal surfaces. Blood investigations revealed low platelet count and raised urea and creatinine. A platelet transfusion was carried out, following which she succumbed to death. Autopsy revealed pink hyaline thrombi in myocardial arteries. What is the likely diagnosis?
Your Answer:
Correct Answer: Thrombotic thrombocytopenic purpura
Explanation:Hyaline thrombi are typically associated with thrombotic thrombocytopenic purpura (TTP), which is caused by non-immunological destruction of platelets. Platelet transfusion is contraindicated in TTP. Platelets and red blood cells also get damaged by loose strands of fibrin deposited in small vessels. Multiple organs start developing platelet-fibrin thrombi (bland thrombi with no vasculitis) typically at arteriocapillary junctions. This is known as ‘thrombotic microangiopathy’. Treatment consists of plasma exchange.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 43
Incorrect
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A 55-year-old woman complains of pain in the proximal and distal interphalangeal joins, and back pain which has increased over the last 4 years and worsens after activity. X-rays reveal Heberden’s and Bouchard’s nodes in her interphalangeal joints and the presence of osteophytes in her spine. What is the most likely diagnosis?
Your Answer:
Correct Answer: Osteoarthritis
Explanation:Osteoarthritis is most common in older adults, predominating in women between the ages of 40 and 70; after this age, men and women are affected equally. It affects an entire joint, with disruption and potential loss of joint cartilage, along with other joint changes, including bone hypertrophy (osteophyte formation). The pain is usually gradual and is worse after activity, with occasional joint swelling. X-ray findings include marginal osteophytes, narrowing of the joint space, increased density of the subchondral bone, subchondral cyst formation, bony remodelling and joint effusions.
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This question is part of the following fields:
- Orthopaedics
- Pathology
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Question 44
Incorrect
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Which of the following coagulation factors cross-links fibrin?
Your Answer:
Correct 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 45
Incorrect
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Which of the following terms best describes the movement of leukocytes towards a specific target?
Your Answer:
Correct Answer: Chemotaxis
Explanation:The movement of leukocytes towards a chemical mediator is termed chemotaxis and the mediators likewise called chemoattractants.
Diapedesis is the squeezing of the leukocytes from the capillary wall into the intercellular space.
Endocytosis is engulfing of a small substance by the cells e.g. glucose, protein, fats.
Margination is lining of the WBC along the periphery of the blood vessel.
Adhesion is attachment with the vessel wall.
Phagocytosis is described as engulfing the bacteria or the offending substance.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 46
Incorrect
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Which of these conditions causes haematuria, hypertension and proteinuria in children, usually after a streptococcal infection?
Your Answer:
Correct Answer: Acute nephritic syndrome
Explanation:Nephritic syndrome (or acute nephritic syndrome) is a syndrome comprising of signs of nephritis. Children between 2 and 12 are most commonly affected, but it may occur at any age. Predisposing factors/causes include:
Infections with group A streptococcal bacteria (acute post-streptococcal glomerulonephritis).
Primary renal diseases: immunoglobulin A nephropathy, membranoproliferative glomerulonephritis, idiopathic rapidly progressive crescentic glomerulonephritis.
Secondary renal diseases: subacute bacterial endocarditis, infected ventriculo–peritoneal shunt, glomerulonephritis with visceral abscess, glomerulonephritis with bacterial, viral or parasitic infections.
Multisystem diseases.
By contrast, nephrotic syndrome is characterized by only proteins moving into the urine.
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This question is part of the following fields:
- Physiology
- Renal
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Question 47
Incorrect
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A young lady visited a doctor with complaints of fever and a dull, continuous pain in the right lumbar region for 6 days. On, enquiry, she recalled passing an increasing number of stools with occasional blood in last few months. Lower gastrointestinal endoscopic biopsy was taken 5 cm proximal to ileocaecal valve which showed transmural inflammation with several granulomas. Tissue section showed the absence of acid-fast bacillus. She denies any history of travel and her stool cultures were negative. What is the likely diagnosis?
Your Answer:
Correct Answer: Crohn’s disease
Explanation:Crohn’s disease is a chronic, inflammatory disease that can affect any part of the gastrointestinal tract but is usually seen in the distal ileum and colon. It is transmural and symptoms include chronic diarrhoea, abdominal pain, fever, anorexia and weight loss. On examination, there is usually abdominal tenderness with a palpable mass or fullness seen occasionally. Rectal bleeding is uncommon (except in isolated colonic involvement) which manifests like ulcerative colitis. Differential diagnosis includes acute appendicitis or intestinal obstruction. 25%-33% patients also have perianal disease in the form of fissure or fistulas.
Extra intestinal manifestations predominate in children, and include: arthritis, pyrexia, anaemia or growth retardation. Histologically, the disease shows crypt inflammation and abscesses initially, which progress to aphthoid ulcers. These eventually develop into longitudinal and transverse ulcers with interspersed mucosal oedema, leading to the characteristic ‘cobblestoned appearance’. Transmural involvement leads to lymphoedema and thickening of bowel wall and mesentery, leading to extension of mesenteric fat on the serosal surface of bowel and enlargement of mesenteric nodes. There can also be hypertrophy of the muscularis mucosae, fibrosis and stricture formation, which can cause bowel obstruction.
Abscesses are common and the disease can also leas to development of fistulas with various other organs, anterior abdominal wall and adjacent muscles. Pathognomonic non-caseating granulomas are seen in 50% cases and they can occur in nodes, peritoneum, liver, and in all layers of the bowel wall. The clinical course does not depend on the presence of granulomas. There is sharp demarcation between the diseased and the normal bowel (skip areas).
35% cases show only the ileal involvement, whereas in 45% cases, both the ileum and colon are involved with a predilection for right side of colon. 20% cases show only colonic involvement, often sparing the rectum (unlike ulcerative colitis). In occasional cases, there is jejunoileitis – involvement of the entire small bowel. The stomach, duodenum and oesophagus are rarely involved, although there has been microscopic evidence of disease involving the gastric antrum in younger patients. The affected small bowel segments show increased rick of cancer. Moreover, patients with colonic disease show a long-term risk of cancer similar to that seen in ulcerative colitis.
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This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
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Question 48
Incorrect
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The ability of the bacteria to cause disease or its virulence is related to :
Your Answer:
Correct Answer: Toxin and enzyme production
Explanation:The pathogenicity of an organism or its ability to cause disease is determined by its virulence factors. Many bacteria produce virulence factors that inhibit the host’s immune system. The virulence factors of bacteria are typically proteins or other molecules that are synthesized by enzymes. These proteins are coded for by genes in chromosomal DNA, bacteriophage DNA or plasmids. The proteins made by the bacteria can poison the host cells and cause tissue damage.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 49
Incorrect
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Calculate the total peripheral resistance for a patient with a blood pressure of 130/70 mm HG and cardiac output of 5 litres / min?
Your Answer:
Correct Answer: 18 mmHg × min/l
Explanation:Total peripheral resistance = Mean arterial pressure/Cardiac output. And the mean arterial pressure = Diastolic pressure + 1/3 (Systolic pressure – Diastolic pressure), i.e., 70 + 1/3 (130-70) = 90 mmHg. Therefore, total peripheral resistance = 90 mmHg/5 l per min = 18 mmHg × min/l.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 50
Incorrect
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A week after a renal transplant the patient received antilymphocyte globulins. Shortly after she developed fever and hypotension. Which of the following mechanisms is involved in this response?
Your Answer:
Correct Answer: Type III hypersensitivity
Explanation:Type III hypersensitivity is characterized by soluble immune complexes which are aggregations of IgG and IgM antibodies with antigens that deposit in different tissues e.g. the skin, joints, kidneys. They can then trigger an immune response by activating the complement cascade. This reaction can take hours to develop and examples include: immuno-complex glomerulonephritis, rheumatoid arthritis, SLE, subacute bacterial endocarditis, arthus reaction and serum sickness.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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SESSION STATS - PERFORMANCE PER SPECIALTY
