-
Question 1
Incorrect
-
A 34-year-old woman is diagnosed with cerebral oedema after suffering a severe head trauma. Which of the following conditions is not likely to be associated with the extracellular oedema?
Your Answer: Increased capillary permeability
Correct Answer: Increased plasma colloid osmotic pressure
Explanation:Cerebral oedema is extracellular fluid accumulation in the brain. Increased capillary permeability, increased capillary pressure, increased interstitial fluid colloid osmotic pressure and lymphatic blockage would increase fluid movement into the interstitial spaces. Increased plasma colloid osmotic pressure, however, would oppose fluid movement from the capillaries into the interstitial compartment.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 2
Incorrect
-
Which of the following conditions of the breast is most often associated with use of oral contraceptives?
Your Answer: Fat necrosis
Correct Answer: Cyst formation
Explanation:Breast cysts are common and are smooth, firm, mobile lumps that can sometimes be tender. Cysts can also be bilateral and are known to recur in 10% of cases. They are more common in women in the third and fourth decades and most often disappear after menopause. Cysts are filled with fluid from the breast which occurs due to the normal menstrual cycle of a woman. The end of the menstrual cycle causes breast cells to swell. After the menses, the cells shrink and the released fluid disappears. However, in some cases this fluid forms a cyst. Incidence of cysts was also linked to use of oral contraceptives.
-
This question is part of the following fields:
- Pathology
- Women's Health
-
-
Question 3
Incorrect
-
A 60-year-old woman has had persistent diarrhoea for a week. A stool test reveals an infection by Clostridium difficile. Which of the following antibiotics could be used to treat the infection?
Your Answer: Clindamycin
Correct Answer: Oral vancomycin
Explanation:Three antibiotics are effective against Clostridium difficile:
Metronidazole 500 mg orally three times daily is the drug of choice, because of superior tolerability, lower price and comparable efficacy.
Oral vancomycin 125 mg four times daily is second-line therapy in particular cases of relapse or where the infection is unresponsive to metronidazole treatment.
Thirdly, the use of linezolid might also be considered.
-
This question is part of the following fields:
- Pathology
- Pharmacology
-
-
Question 4
Correct
-
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: 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.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 5
Correct
-
The Henderson–Hasselbalch equation describes the derivation of pH as a measure of acidity. According to this equation, the buffering capacity of the system is at maximum when the number of free anions compared with undissociated acid is:
Your Answer: Equal
Explanation:In 1908, Lawrence Joseph Henderson wrote an equation describing the use of carbonic acid as a buffer solution. Later, Karl Albert Hasselbalch re-expressed that formula in logarithmic terms, resulting in the Henderson–Hasselbalch equation. The equation is also useful for estimating the pH of a buffer solution and finding the equilibrium pH in acid–base reactions. Two equivalent forms of the equation are: pH = pKa + log10 [A–]/[HA] or pH = pKa + log10 [base]/[acid]. Here, pKa is − log10(Ka) where Ka is the acid dissociation constant, that is: pKa = –log10(Ka) = –log10 ([H3 O+][A–]/[HA]) for the reaction: HA + H2 O ≈ A– + H3 O+ In these equations, A– denotes the ionic form of the relevant acid. Bracketed quantities such as [base] and [acid] denote the molar concentration of the quantity enclosed. Maximum buffering capacity is found when pH = pKa or when the number of free anions to undissociated acid is equal and buffer range is considered to be at a pH = pKa ± 1.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 6
Correct
-
A patient presented with continuous bleeding several hours after dental extraction. Which of the following findings is most often associated with clinical bleeding?
Your Answer: Factor IX deficiency
Explanation:Factor IX deficiency, also called Haemophilia B or Christmas disease, is a disorder caused by missing or defective clotting factor IX. Deficiency of the factor IX causes irregular bleeding that can happen spontaneously or after mild trauma, surgery and dental extractions.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 7
Correct
-
A 62-year-old woman presented to the doctor complaining of spine pain, fatigue and oliguria. She is diagnosed with chronic renal failure. Dipstick testing shows no protein, glucose, nitrite or ketones but a semi-quantitative sulphosalicylic acid test for urine protein is positive. Which of the following is the most probable cause of chronic renal failure in this patient.
Your Answer: Multiple myeloma
Explanation:Dipstick results are negative because the proteins found in the urine of this patient are not albumin but Bence Jones proteins. A Bence Jones protein is a monoclonal globulin protein commonly detected in patients affected by multiple myeloma. Multiple myeloma is a malignancy of plasma cells characterised by the production of monoclonal immunoglobulin. Symptoms include bone pain, bone fractures, bleeding, neurologic symptoms, fatigue, frequent infections and weight loss.
-
This question is part of the following fields:
- Pathology
- Renal
-
-
Question 8
Correct
-
A 38-year old lady presented to the hospital with abnormal passing of blood per vagina. On examination, she was found to have an endocervical polypoidal mass. On enquiry, she gave history of oral contraceptive usage for 3 years. What finding is expected on the histopathology report of biopsy of the mass?
Your Answer: Microglandular hyperplasia
Explanation:Endocervical polyps or microglandular hyperplasia are benign growths occurring in the endocervical canal, in about 2-5% women and occur secondary to use of oral contraceptives. They are usually < 1cm in size, friable and reddish-pink. Usually asymptomatic, they can cause bleeding or become infected, leading to leucorrhoea (purulent vaginal discharge). They are usually benign but need to be differentiated from adenocarcinomas by histology.
-
This question is part of the following fields:
- Pathology
- Women's Health
-
-
Question 9
Incorrect
-
A 44-year old man, who was euthyroid underwent thyroidectomy following neoplastic cells found on fine-needle aspiration. Frozen section of multiple thyroid masses showed malignant neoplasm of polygonal cells in nests. The neoplasm also showed presence of amyloid which was positive with Congo-red staining. Immunoperoxidase staining for calcitonin was also positive. Chest X-ray revealed no abnormality. However, his blood pressure was found to be raised, and his serum ionised calcium was high. What is the likely diagnosis?
Your Answer: Multiple endocrine neoplasia type I
Correct Answer: Multiple endocrine neoplasia type IIA
Explanation:MEN (Multiple Endocrine Neoplasia) syndromes are a group of three separate familial disease which consists of adenomatous hyperplasia and neoplasia in several endocrine glands. All three conditions are inherited as an autosomal dominant trait, with a single gene producing multiple effects. MEN IIA is characterized by medullary carcinoma of the thyroid, pheochromocytoma and hyperparathyroidism. It should be suspected in patients with bilateral pheochromocytoma, a familial history of MEN, or at least two characteristic endocrine manifestations. Genetic testing is used to confirm the diagnosis. Early diagnosis is crucial to aid in complete excision of the localized tumour. Pheochromocytomas can be detected by plasma free metanephrines and fractionated urinary catecholamines, particularly adrenaline (epinephrine).
Imaging studies such as computed tomography or magnetic resonance imaging might also prove useful. Hyperparathyroidism is diagnosed by the standard finding of hypercalcaemia, hypophosphatemia and an increased parathyroid hormone level. Once MEN IIA syndrome is identified in any patient, it is recommended that his or her first-degree relatives and any other symptomatic also undergo genetic testing. Relatives should be subjected to annual screening for hyperparathyroidism and pheochromocytoma beginning in early childhood and continue indefinitely. Serum calcium levels help in screening for hyperparathyroidism. Similarly, screening for pheochromocytoma is by history, measurement of the blood pressure and laboratory testing.
-
This question is part of the following fields:
- Endocrine
- Pathology
-
-
Question 10
Correct
-
Question 11
Correct
-
Which of the following is the cause of flattened (notched) T waves on electrocardiogram (ECG)?
Your Answer: Hypokalaemia
Explanation:The T-wave is formed due to ventricular repolarisation. Normally, it is seen as a positive wave. It can be normally inverted (negative) in V1 (occasionally in V2-3 in African-Americans/Afro-Caribbeans). Hyperacute T-waves are the earliest ECG change of acute myocardial infarction. ECG findings of hyperkalaemia include high, tent-shaped T-waves, a small P-wave and a wide QRS complex. Hypokalaemia results in flattened (notched) T-waves, U-waves, ST-segment depression and prolonged QT interval.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 12
Correct
-
If a 70-year-old man with known atrial fibrillation dies suddenly, which of these is the most likely cause of death?
Your Answer: Thromboembolism
Explanation:In atrial fibrillation, the abnormal atrial contraction can cause blood to stagnate in the left atrium and form a thrombus, which may then embolize. The patient’s history of AF suggest an embolic disease, which lead to his death.
-
This question is part of the following fields:
- Cardiovascular
- Pathology
-
-
Question 13
Incorrect
-
Question 14
Incorrect
-
A 59-year old gentleman admitted for elective cholecystectomy was found to have a haemoglobin 12.5 g/dl, haematocrit 37%, mean corpuscular volume 90 fl, platelet count 185 × 109/l, and white blood cell count 32 × 109/l; along with multiple, small mature lymphocytes on peripheral smear. The likely diagnosis is:
Your Answer: Infectious mononucleosis
Correct Answer: Chronic lymphocytic leukaemia
Explanation:CLL or chronic lymphocytic leukaemia is the most common leukaemia seen in the Western world. Twice more common in men than women, the incidence of CLL increases with age. About 75% cases are seen in patients aged more than 60 years. The blood, marrow, spleen and lymph nodes all undergo infiltration, eventually leading to haematopoiesis (anaemia, neutropenia, thrombocytopenia), hepatomegaly, splenomegaly and decreased production of immunoglobulin. In 98% cases, CD+5 B cells undergo malignant transformation.
Often diagnosed on blood tests while being evaluated for lymphadenopathy, CLL causes symptoms like fatigue, anorexia, weight loss, pallor, dyspnoea on exertion, abdominal fullness or distension. Findings include multiple lymphadenopathy with minimal-to- moderate hepatomegaly and splenomegaly. Increased susceptibility to infections is seen. Herpes Zoster is common. Diffuse or maculopapular skin infiltration can also be seen in T-cell CLL.
Diagnosis is by examination of peripheral blood smear and marrow: hallmark being a sustained, absolute leucocytosis (>5 ×109/l) and increased lymphocytes in the marrow (>30%). Other findings can include hypogammaglobulinemia (<15% of cases) and, rarely, raised lactate dehydrogenase (LDH). Only 10% cases demonstrate moderate anaemia and/or thrombocytopenia.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 15
Correct
-
A 56-year-old woman weighs 75 kg. In this patient, total body water, intracellular fluid and extracellular fluid are respectively:
Your Answer: 45 l, 30 l, 15 l
Explanation:The percentages of body water contained in various fluid compartments add up to total body water (TBW). This water makes up a significant fraction of the human body, both by weight and by volume. The total body water (TBW) content of humans is approximately 60% of body weight. Two-thirds is located in the intracellular and one-third in the extracellular compartment. So, in a 75-kg individual, TBW = 60 × 75/100 = 45 l. Intracellular content = 2/3 × 45 = 30 l and extracellular content = 1/3 × 45 = 15 l.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 16
Incorrect
-
A 29-year-old woman presents to the doctor complaining of cough, shortness of breath, fever and weight loss. Chest X-ray revealed bilateral hilar and mediastinal lymph node enlargement and bilateral pulmonary opacities. Non-caseating granulomas were found on histological examination. The most likely diagnosis is:
Your Answer: Interstitial pneumonitis
Correct Answer: Sarcoidosis
Explanation:Sarcoidosis is an inflammatory disease of unknown aetiology that affects multiple organs but predominantly the lungs and intrathoracic lymph nodes. Systemic and pulmonary symptoms may both be present. Pulmonary involvement is confirmed by a chest X-ray and other imaging studies. The main histological finding is the presence of non-caseating granulomas.
-
This question is part of the following fields:
- Pathology
- Respiratory
-
-
Question 17
Correct
-
Renal function is an indication of the state of the kidney, measured by glomerular filtration rate (GFR). In a healthy person, GFR would be greatly increased by:
Your Answer: Substantial increases in renal blood flow
Explanation:An increase in the rate of renal blood flow (RBF) greatly increases the glomerular filtration rate (GFR). The more plasma available (from increased RBF), the more filtrate is formed. Glomerular filtration rate (GFR) is the volume of fluid filtered from the renal (kidney) glomerular capillaries into the Bowman’s capsule per unit time. Central to the physiologic maintenance of GFR is the differential basal tone of the afferent and efferent arterioles.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 18
Incorrect
-
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: Aplastic anaemia
Correct 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).
-
This question is part of the following fields:
- Microbiology
- Pathology
-
-
Question 19
Incorrect
-
A 15 month old boy has a history of repeated bacterial pneumonia, failure to thrive and a sputum culture positive for H.influenzea and S.pneumoniae. There is no history of congenital anomalies. He is most likely suffering from?
Your Answer: Acute leukaemia
Correct Answer: X-linked agammaglobulinemia
Explanation:Recurrent bacterial infections may be due to lack of B-cell function, consequently resulting in a lack of gamma globulins production. Once the maternal antibodies have depleted, the disease manifests with greater severity and is called x-linked agammaglobulinemia also known as ‘X-linked hypogammaglobulinemia’, ‘XLA’ or ‘Bruton-type agammaglobulinemia. it is a rare x linked genetic disorder that compromises the bodies ability to fight infections.
Acute leukaemia causes immunodeficiency but not so specific.
DiGeorge syndrome is due to lack of T cell function.
Aplastic anaemia and EBV infection does not cause immunodeficiency.
-
This question is part of the following fields:
- Inflammation & Immunology; Respiratory
- Pathology
-
-
Question 20
Incorrect
-
A Jewish man was diagnosed with haemophilia C. Which of the following factors is deficient in this form of haemophilia?
Your Answer: Factor XII
Correct Answer: Factor XI
Explanation:Haemophilia C, also known as plasma thromboplastin antecedent (PTA) deficiency or Rosenthal syndrome, is a condition caused by the deficiency of the coagulation factor XI. The condition is rare and it is usually found in Ashkenazi Jews.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 21
Incorrect
-
A 14 year old girl suffers from haemophilia A and chronic knee pain with progressive swelling and deformity over the last 4 years. Test results reveal a significantly reduced factor VIII activity. Which of the following is seen in the knee joint space after an acute painful episode?
Your Answer: Anthracotic pigment
Correct Answer: Cholesterol crystals
Explanation:Due to breakdown of the red blood cell membrane in haemophilic patients, cholesterol crystals are formed by the lipids. On the other hand lipofuscin deposition does not occur in haemolysis or haemorrhage. Neutrophil accumulation suggests acute inflammation. Anthracotic pigment is an exogenous carbon pigment that deposits in the lung from dust. Russell bodies are intracellular accumulations of immunoglobins in plasma cells. Curschmann’s spirals and Charcot Leyden crystals are pathognomonic of asthma.
-
This question is part of the following fields:
- Cell Injury & Wound Healing; Haematology
- Pathology
-
-
Question 22
Correct
-
Laboratory findings in a patient with dark urine and yellowish skin revealed a prolonged prothrombin time. Which of the following is the most likely cause of this finding?
Your Answer: Liver damage
Explanation:Various conditions may prolong the prothrombin time (PT), including: warfarin use, vitamin K deficiency, liver disease, disseminated intravascular coagulopathy, hypofibrinogenemia, heparin infusion, massive blood transfusion and hypothermia. Liver disease causes prolonging of PT due to diminished synthesis of clotting factors. Dark urine colour and jaundice are indicators of the presence of a liver disease in this patient.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 23
Correct
-
A 24-year-old patient with recurrent episodes of deep vein thrombosis presents again to the clinic. Deficiency of which of the following blood proteins is the most probable cause of this episode?
Your Answer: Antithrombin III
Explanation:Antithrombin III (ATIII) is a blood protein that acts by inhibiting blood coagulation by neutralizing the enzymatic activity of thrombin.
Antithrombin III deficiency is an autosomal dominant disorder that leads to an increased risk of venous and arterial thrombosis. Clinical manifestations typically appear in young adulthood.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 24
Correct
-
A 50-year-old gentleman was recently diagnosed with hypertension, with no other abnormalities on physical examination. Further investigations revealed the following :
Na+ 144 mmol/l
K+ 3.0 mmol/l
Cl- 107 mmol/l
Bicarbonate 25 mmol/l.
Blood glucose 5.8 mmol/l.
What is the likely diagnosis?Your Answer: Conn syndrome
Explanation:Overproduction of aldosterone (a mineralocorticoid) by the adrenal glands is known as Conn’s syndrome. It can be either due to an aldosterone-secreting adrenal adenoma (50-60% cases) or adrenal gland hyperplasia (40-50% cases). Excess aldosterone leads to sodium and water retention, along with potassium excretion. This leads to arterial (non-essential) hypertension. Conn’s syndrome is the commonest cause of primary hyperaldosteronism. Other symptoms include muscle cramps, headache (due to hypokalaemia) and metabolic alkalosis, which occurs due to increased secretion of H+ ions by the kidney. The raised pH of the blood traps calcium leading to symptoms of hypocalcaemia, which can be mimicked by liquorice ingestion and Liddle syndrome. To diagnose Conn’s syndrome, the ratio of renin and aldosterone is measured. Due to suppression of renin secretion, there is low renin to aldosterone ratio (<0.05). However, anti-hypertensives may affect the test results and should be withdrawn for 6 weeks. Computed tomography can also be done to detect the presence of adrenal adenoma. Cushing’s syndrome does not cause hypokalaemia with normal serum glucose levels. Nelson’s syndrome refers to increased ACTH secretion due to pituitary adenoma. Pheochromocytoma will not lead to hypokalaemia even though hypertension can be seen.
-
This question is part of the following fields:
- Endocrine
- Pathology
-
-
Question 25
Correct
-
Which of the following conditions is characterized by generalised oedema due to effusion of fluid into the extracellular space?
Your Answer: Anasarca
Explanation:Anasarca (or ‘generalised oedema’) is a condition characterised by widespread swelling of the skin due to effusion of fluid into the extracellular space. It is usually caused by liver failure (cirrhosis of the liver), renal failure/disease, right-sided heart failure, as well as severe malnutrition/protein deficiency.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 26
Correct
-
A previously healthy 40-year-old housewife suddenly complains of a headache and loses consciousness. A CT scan reveals subarachnoid haemorrhage. Which of the following is the most probable cause?
Your Answer: Ruptured berry aneurysm
Explanation:Saccular aneurysms, also known as berry aneurysms, appear as a round outpouching and are the most common form of cerebral aneurysm. They are a congenital intracranial defect, and haemorrhage can occur at any age, but is most common between the ages of 40-65 years. A second rupture (rebleeding) sometimes occurs, most often within about 7 days of the first bleed.
-
This question is part of the following fields:
- Neurology
- Pathology
-
-
Question 27
Correct
-
A 63-year old lady presents with pain in multiple bones and renal failure. On enquiry, there is history of recurrent pneumonia in the past. What will be the likely finding on her bone marrow biopsy?
Your Answer: Plasma cells
Explanation:Multiple myeloma is a plasma cell malignancy that produce excessive monoclonal immunoglobulins. The disease presents with bone pains, renal dysfunction, increased calcium, anaemia and recurrent infections. Diagnosis is by demonstrating the presence of M-protein in urine or serum, lytic bone lesions, light chain proteinuria or excessive plasma cells on marrow biopsy.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 28
Correct
-
A 55 year old lady underwent an uneventful appendicectomy. Two hours later, her arterial blood gas analysis on room revealed pH: 7.30, p(CO2): 53 mmHg and p(O2): 79 mmHg. What is the most likely cause of these findings?
Your Answer: Alveolar hypoventilation
Explanation:In the given problem, there is respiratory acidosis due to hypercapnia from a low respiratory rate and/or volume (hypoventilation). Causes of hypoventilation include conditions impairing the central nervous system (CNS) respiratory drive, impaired neuromuscular transmission and other causes of muscular weakness (drugs and sedatives), along with obstructive, restrictive and parenchymal pulmonary disorders. Hypoventilation leads to hypoxia and hypercapnia reduces the arterial pH. Severe acidosis leads to pulmonary arteriolar vasoconstriction, systemic vascular dilatation, reduced myocardial contractility, hyperkalaemia, hypotension and cardiac irritability resulting in arrhythmias. Raised carbon dioxide concentration also causes cerebral vasodilatation and raised intracranial pressure. Over time, buffering and renal compensation occurs. However, this might not be seen in acute scenarios where the rise in p(CO2) occurs rapidly.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 29
Correct
-
A 49-year-old woman with acute renal failure has a total plasma [Ca2+] = 2. 5 mmol/l and a glomerular filtration rate of 160 l/day. What is the estimated daily filtered load of calcium?
Your Answer: 240 mmol/day
Explanation:Calcium is the most abundant mineral in the human body. The average adult body contains in total approximately 1 kg of calcium of which 99% is in the skeleton in the form of calcium phosphate salts. The extracellular fluid (ECF) contains approximately 22 mmol, of which about 9 mmol is in the plasma. About 40% of total plasma Ca2+ is bound to proteins and not filtered at the glomerular basement membrane. Therefore, the estimated daily filtered load is 1.5 mmol/l × 160 l/day = 240 mmol/day. The exact amount of free versus total Ca2+ depends on the blood pH: free Ca2+ increases during acidosis and decreases during alkalosis.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 30
Correct
-
If the blood flow is constant, oxygen extraction by tissues will show the greatest decrease due to which of the following interventions?
Your Answer: Tissue cooling
Explanation:With a constant blood flow to a given tissue bed, there will be an increase in oxygen extraction by the tissue with the following; an increase in tissue metabolism and oxygen requirements: warming (or fever), exercise, catecholamines and thyroxine. With cooling, the demand for oxygen decreases, leading to decreased oxygen extraction.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 31
Correct
-
During cardiac catheterisation, if the blood sample from the catheter shows an oxygen saturation of 70%, and the pressure ranging from 12 to 24 mm Hg, it implies that the catheter tip is located in the:
Your Answer: Pulmonary artery
Explanation:Normal values for various parameters are as follows:
Systolic arterial blood pressure (SBP): 90–140 mmHg.
Diastolic arterial blood pressure: 60–90 mmHg.
Mean arterial blood pressure (MAP): SBP + (2 × DBP)/3 (normal range: 70-105 mmHg).
Right atrial pressure (RAP): 2–6 mmHg.
Systolic right ventricular pressure (RVSP): 15–25 mmHg.
Diastolic right ventricular pressure (RVDP): 0–8 mmHg.
Pulmonary artery pressure (PAP): Systolic (PASP) is 15-25 mmHg and Diastolic (PADP) is 8–15 mmHg.
Pulmonary artery wedge pressure (PAWP): 6–12 mmHg.
Left atrial pressure (LAP): 6–12 mmHg.
Thus, the given value indicates that the position of catheter tip is likely to be in the pulmonary artery.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 32
Correct
-
When a penile tumour invades the subepithelial connective tissue of the penis, what is its stage?
Your Answer: T1
Explanation:The TNM staging used for penile cancer is as follows:
TX: primary tumour cannot be assessed
T0: primary tumour is not evident
Tis: carcinoma in situ is present
Ta: non-invasive verrucous carcinoma is present
T1: tumour is invading subepithelial connective tissue
T2: tumour is invading the corpora spongiosum or cavernosum
T3: tumour invading the urethra or prostate
T4: tumour invading other adjacent structures.
In this case, the patient has a T1 tumour.
-
This question is part of the following fields:
- Pathology
- Urology
-
-
Question 33
Correct
-
A biopsy taken from the respiratory passage of a 37 year old male, chronic smoker will mostly likely show which cellular adaptation?
Your Answer: Stratified squamous metaplasia
Explanation:Metaplasia is a change in the cell type caused in part due to an extrinsic stress on the organ. It involves a change in the surface epithelium from one cell type to the another, most commonly squamous to columnar. This is a reversible process, and removal of the stress should theoretically reverse the surface epithelium back to normal morphology. Respiratory tract metaplasia is a classic example, in which the normal pseudostratified columnar epithelium is replaced by stratified squamous epithelium to better cope with the stress. Under continuous stress metaplasia can progress to dysplasia which is a disordered growth of cells eventually leading to the development of carcinoma.
-
This question is part of the following fields:
- Cell Injury & Wound Healing; Respiratory
- Pathology
-
-
Question 34
Incorrect
-
Which of the following is the most likely cause of massive splenomegaly in a 35-year old gentleman?
Your Answer: Sickle cell anaemia
Correct Answer: Myelofibrosis
Explanation:Causes of massive splenomegaly include chronic myelogenous leukaemia, chronic lymphocytic leukaemia, lymphoma, hairy cell leukaemia, myelofibrosis, polycythaemia vera, sarcoidosis, Gaucher’s disease and malaria.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 35
Correct
-
Risk factors for hepatocellular carcinoma do NOT include:
Your Answer: Heptitis E
Explanation:Risk factors for hepatocellular carcinoma include hepatitis B and C, aflatoxin, anabolic steroids, alcohol cirrhosis and primary liver disease.
-
This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
-
-
Question 36
Correct
-
A 62-year-old male smoker, presented with shortness of breath, chronic cough and haemoptysis over the last three months. He has developed a fat pad in the base of his neck, rounded face, acne and osteoporosis. Which of the following is the most likely pulmonary disease that is causing these symptoms and findings?
Your Answer: Small-cell anaplastic carcinoma
Explanation:Small cell lung cancer is a highly aggressive form of lung cancer. It is thought to originate from neuroendocrine cells in the bronchus called Feyrter cells and is often associated to ectopic production of hormones like ADH and ACTH that result in paraneoplastic syndromes and Cushing’s syndrome.
-
This question is part of the following fields:
- Pathology
- Respiratory
-
-
Question 37
Incorrect
-
Following a bee sting, a women develops a 2cm red, raised, swollen lesion at the site of the sting . Which of the following findings is likely to be seen in this lesion?
Your Answer: Foreign body reaction
Correct Answer: Vasodilation
Explanation:Inflammation is the immediate response of the body towards infections or irritations. The cardinal signs of inflammation are 1. redness/rubor, 2. tumour/swelling, 3.dolar/pain, 4.calor/heat and organ dysfunction (function laesa). Inflammation has 2 components; vascular and cellular. Blood vessels dilate upstream of the inflamed area leading to the rubor and calor and constrict downstream, increasing pressure and causing fluid to leak out of the capillary, resulting in swelling. The cellular component includes infiltration by neutrophils. Leukocyte arrival and functions include; 1. margination: cells marginated 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 resulting in adhesion, 4. diapedesis and chemotaxis: diapedesis is the transmigration of the leukocyte across the endothelium of the capillary and towards a chemotactic product and 5. phagocytosis: engulfing the offending substance/cell.
-
This question is part of the following fields:
- Inflammation & Immunology
- Pathology
-
-
Question 38
Incorrect
-
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: Vomiting
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.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
-
-
Question 39
Correct
-
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 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.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 40
Incorrect
-
A 30 year old lawyer presented with a history of pleural effusions, pericarditis, arthralgia without joint deformity and episodes of myalgia for the past 12 months. Blood tests reveal a normocytic anaemia. Which of the following tests should be performed to investigate this condition further?
Your Answer: Bone marrow biopsy
Correct Answer: Antinuclear antibody test
Explanation:These non specific findings are suggestive of autoimmune disease. Antinuclear antibody (ANA) is the first test that should be performed when autoimmune diseases are suspected and later on more specific tests should be performed. This tests aids in the diagnosis of SLE, scleroderma, Sjogren’s syndrome, Raynaud’s disease, juvenile chronic arthritis, rheumatoid arthritis and antiphospholipid antibody syndrome etc. To confirm the disease a history, physical examination along with specific tests are required.
CPK is more specific for acute conditions.
ESR is a non specific test for inflammation.
-
This question is part of the following fields:
- Inflammation & Immunology
- Pathology
-
-
Question 41
Correct
-
A 47 -year-old male was admitted due to a bleeding peptic ulcer. On his 3rd hospital day, he developed a cardiac arrhythmia. His serum potassium was markedly elevated. What is the most likely cause of hyperkalaemia in this patient?
Your Answer: Multiple blood transfusions
Explanation:Patients with gastrointestinal bleeding often require blood transfusion. Among the various side effects of blood transfusions, is the increase of potassium levels. The use of stored blood for transfusions is followed by an increase of serum potassium levels. Potassium level increases are more pronounced in patients who receive blood stored for more than 12 d. Furthermore, the lysis and destruction of red blood cells, especially in the transfusion of older PRBCs, can further increase potassium levels. Excessive use of a PPi has been associated with hyperkaelemia however would be less likely in this acute setting.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
-
-
Question 42
Correct
-
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.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 43
Correct
-
Which of the following features is indicative of poor prognosis in a case of breast carcinoma?
Your Answer: Axillary lymph node metastases
Explanation:Lymphatic spread indicates poor prognosis. Presence of family history is not a prognostic factor despite being linked to higher incidence. Aneuploidy is a poor prognostic factor. A breast tumour positive for oestrogen receptors is a good prognostic factor as it increases the responsiveness of the tumour to certain therapies. In-situ tumours carry the best prognosis.
-
This question is part of the following fields:
- Pathology
- Women's Health
-
-
Question 44
Correct
-
Calculate the cardiac output of a patient with the following measurements: oxygen uptake 200 ml/min, oxygen concentration in the peripheral vein 7 vol%, oxygen concentration in the pulmonary artery 10 vol% and oxygen concentration in the aorta 15 vol%.
Your Answer: 4000 ml/min
Explanation:The Fick’s principle states that the uptake of a substance by an organ equals the arteriovenous difference of the substance multiplied by the blood flowing through the organ. We can thus calculate the pulmonary blood flow with pulmonary arterial (i.e., mixed venous) oxygen content, aortic oxygen content and oxygen uptake. The pulmonary blood flow, systemic blood flow and cardiac output can be considered the same assuming there are no intracardiac shunts. Thus, we can calculate the cardiac output. Cardiac output = oxygen uptake/(aortic − mixed venous oxygen content) = 200 ml/min/(15 ml O2/100 ml − 10 ml O2/100 ml) = 200 ml/min/(5 ml O2/100 ml) = 200 ml/min/0.05 = 4000 ml/min.
It is crucial to remember to use pulmonary arterial oxygen content and not peripheral vein oxygen content, when calculating the cardiac output by Fick’s method.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 45
Incorrect
-
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: Zollinger-Ellison syndrome
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).
-
This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
-
-
Question 46
Correct
-
Staphylococcus aureus can be identified in the laboratory based on the clotting of plasma. Which microbial product is responsible for this activity?
Your Answer: Coagulase
Explanation:Staphylococcus aureus is the most pathogenic species and is implicated in a variety of infections. S. aureus can be identified due to its production of coagulase. The staphylococcal enzyme coagulase will cause inoculated citrated rabbit plasma to gel or coagulate. The coagulase converts soluble fibrinogen in the plasma into insoluble fibrin.
-
This question is part of the following fields:
- Microbiology
- Pathology
-
-
Question 47
Incorrect
-
A 57-year-old male smoker noted a lump on his inner lip. Upon physical examination the lump measured more than 2 cm but less than 4 cm in its greatest dimension. He is diagnosed with squamous cell carcinoma of the lip. What is the stage of the patient's cancer according to the TNM staging for head and neck cancers?
Your Answer: T1
Correct Answer: T2
Explanation:Head and neck cancer is a group of cancers that starts within the mouth, nose, throat, larynx, sinuses, or salivary glands. The TNM staging system used for head and neck cancers is a clinical staging system that allows physicians to compare results across patients, assess prognosis, and design appropriate treatment regimens. The staging is as follows; Primary tumour (T): Tis: pre-invasive cancer (carcinoma in situ), T0: no evidence of primary tumour, T1: tumour 2 cm or less in its greatest dimension, T2: tumour more than 2 cm but not more than 4 cm, T3: tumour larger than 4 cm, T4: tumour with extension to bone, muscle, skin, antrum, neck, etc and TX: minimum requirements to assess primary tumour cannot be met. Regional lymph node involvement (N): N0: no evidence of regional lymph node involvement, N1: evidence of involvement of movable homolateral regional lymph nodes, N2: evidence of involvement of movable contralateral or bilateral regional lymph nodes, N3: evidence of involvement of fixed regional lymph nodes and NX: Minimum requirements to assess the regional nodes cannot be met. Distant metastases (M): M0: no evidence of distant metastases, M1: evidence of distant metastases and MX: minimum requirements to assess the presence of distant metastases cannot be met. Staging: Stage I: T1 N0 M0, Stage II: T2 N0 M0, Stage III: T2NOMO and T3N1MO, Stage IV: T4N1M0, any TN2M0, any TN3M0, any T and any NM1. The depth of infiltration is predictive of the prognosis. With increasing depth of invasion of the primary tumour, the risk of nodal metastasis increases and survival decreases. The patient in this scenario therefore has a T2 tumour.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 48
Correct
-
A 40 year old woman, who is under anaesthesia for an elective procedure, received an antibiotic injection. She immediately developed a rash and her airway constricted raising the airway pressure. Which mechanism is responsible for this reaction?
Your Answer: Type I hypersensitivity
Explanation:Type I hypersensitivity reaction is an immediate reaction that occurs due to binding of the antigen with antibodies attached to mast cells in a previously sensitized person. It has an immediate phase, which is characterised by vasodilation, leakage of plasma, smooth muscle spasm, or glandular secretions. This manifests in about 5-30 min and usually resolves within 60 mins. The delayed phase follows after 24 hours and can persist up to several days. It is due to infiltration of eosinophils, neutrophils, basophils and CD4+ cells and leads to tissue destruction. The nature of the reaction varies according to the site. It can take the form of skin allergy, hives, allergic rhinitis, conjunctivitis, bronchial asthma or food allergy.
-
This question is part of the following fields:
- Inflammation & Immunology
- Pathology
-
-
Question 49
Correct
-
Calculate the cardiac stroke volume of a patient whose oxygen consumption (measured by analysis of mixed expired gas) is 300 ml/min, arterial O2 content is 20 ml/100 ml blood, pulmonary arterial O2 content is 15 ml/100 ml blood and heart rate is 60/min.
Your Answer: 100 ml
Explanation:By Fick’s principle, VO2 = Q × (CA (O2) − CV (O2)) where VO2 = O2 consumption, Q = cardiac output and CA(O2) and CV(O2) are arterial and mixed venous O2 content respectively. Thus, in the given problem, 300 ml O2/min = Q × (20−15) ml O2/100 ml. Thus, Q = 6000 ml blood/min. Then, we can calculate stroke volume by dividing the cardiac output with heart rate. Thus, stroke volume = 6000 ml/min divided by 60/min stroke volume = 100 ml.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 50
Correct
-
Diffusion is the movement of molecules from a region of high concentration to a region of low concentration. Which of these changes will decrease the rate of diffusion of a substance?
Your Answer: An increase in the molecular weight of the substance
Explanation:Unless given IV, a drug must cross several semipermeable cell membranes before it reaches the systemic circulation. Drugs may cross cell membranes by diffusion, amongst other mechanisms. The rate of diffusion of a substance is proportional to the difference in the concentration of the diffusing substance between the two sides of the membrane, the temperature of the solution, the permeability of the membrane and, in the case of ions, the electrical potential difference between the two sides of the membrane.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 51
Correct
-
When a patient that is less than 21 years of age develops a bone tumour. What is the most common benign bone tumour that would be considered in individuals below 21 years?
Your Answer: Osteochondroma
Explanation:Osteochondroma is a benign new bone growth that protrudes from the outer contour of bones and is capped by growing cartilage. Nearly 80% of these lesions are noted before the age of 21 years.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 52
Correct
-
A patient with chronic renal disease, missed a day of his dialysis schedule., His serum potassium was 7.6 mmol/L when his electrolytes were checked. What is the ECG finding expected in this patient?
Your Answer: Tented T waves
Explanation:ECG characteristics of hyperkalaemia may show the following changes: P-waves are widened and of low amplitude due to slowing of conduction, widened QRS complex, QRS-T fusion, loss of ST segment and tall tented T waves.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
-
-
Question 53
Incorrect
-
Which of the following malignancies is likely to have the best prognosis?
Your Answer: Follicular carcinoma of the thyroid
Correct Answer: Papillary carcinoma of the thyroid
Explanation:Papillary carcinoma accounts for 70-80% of all thyroid cancers and is seen commonly in people aged 30-60 years. It is more aggressive in elderly patients. 10-20% cases may have recurrence or persistent disease. More common in females with a female to male ratio of 3:1. Papillary carcinomas can also contain follicular carcinomas. The common route of spread is through lymphatics to regional nodes in one-third cases and pulmonary metastasis can also occur. Papillary carcinomas of the thyroid have the best prognosis, especially in patients less than 45 years of age with small tumours confined to the thyroid gland.
-
This question is part of the following fields:
- Endocrine
- Pathology
-
-
Question 54
Correct
-
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.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 55
Correct
-
Calculate the cardiac output in an adult male with the following parameters:
Heart rate 70 beats/min
Arterial [O2] 0.24 ml O2/min
Venous [O2] 0.16 ml O2/mi
Whole body O2 consumption 500 ml/min
Pulmonary diastolic pressure 15 mmHg
Pulmonary systolic pressure 25 mmHg
Wedge pressure 5 mmHg.Your Answer: 6.25 l/min
Explanation:As per Fick’s principle, VO2 = (CO × CAO2) – (CO × CVO2) where VO2 = oxygen consumption, CO = cardiac output, CAO2 = oxygen concentration of arterial blood and CVO2 = oxygen concentration of venous blood. Thus, CO = VO2/CAO2– CVO2, CO = 500/0.24 – 0.16, CO = 500/0.8, CO = 6.25 l/min.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 56
Incorrect
-
A 72-year-old male presents with dysuria and chronic haematuria. He was diagnosed with bladder cancer and tumour invasion of the perivesical fat. What is the stage of the patient's bladder cancer?
Your Answer: T2
Correct Answer: T3
Explanation:Bladder cancer is the growth of abnormal or cancerous cells on the inner lining of the bladder wall. The staging is as follows; stage 0is (Tis, N0, M0): Cancerous cells in the inner lining tissue of the bladder only, stage I (T1, N0, M0): tumour has spread onto the bladder wall, stage II (T2, N0, M0): tumour has penetrated the inner wall and is present in muscle of the bladder wall, stage III (T3, N0, M0): tumour has spread through the bladder to fat around the bladder and stage IV: (T4, N0, M0): tumour has grown through the bladder wall and into the pelvic or abdominal wall. The stage of cancer in the case presented is T3 because of the invasion of perivesical fat.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 57
Correct
-
The extent of cancer growth can be described through staging. What is taken into consideration when staging a cancer?
Your Answer: Local invasion
Explanation:Cancer stage is based on four characteristics: the size of cancer, whether the cancer is invasive or non-invasive, whether the cancer has spread to the lymph nodes, and whether the cancer has spread to other parts of the body, in this case beyond the breast. Staging is important as it is often a good predictor of outcomes and treatment is adjusted accordingly.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 58
Correct
-
Which of these substances is secreted by pericytes in the juxtaglomerular cells?
Your Answer: Renin
Explanation:The juxtaglomerular cells synthesise, store and secrete the enzyme renin in the kidney. They are specialised smooth muscle cells in the wall of the afferent arteriole that delivers blood to the glomerulus and thus play a critical role in the renin– angiotensin system and so in renal autoregulation.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 59
Correct
-
Which of the following changes in the histology of the cell is most likely to be accompanied by disruption of the cell membrane following an injury?
Your Answer: Coagulative necrosis
Explanation:The process of necrosis ends with the rupture of the cell membrane and the consequent release of the cellular components into the surrounding tissue. Apoptosis, pyknosis and karyorrhexis are not reversible events but the cell membrane remains intact. Cloudy swelling and hydropic changes are also reversible but again the cell membrane remains intact and they are therefore different and distinct from necrosis.
-
This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
-
-
Question 60
Incorrect
-
Intracellular shifting of hydrogen ions can generate a metabolic alkalosis. In which of the following conditions is metabolic alkalosis caused by this mechanism ?
Your Answer: Milk-alkali syndrome
Correct Answer: Hypokalaemia
Explanation:Metabolic alkalosis is characterized by a primary increase in the concentration of serum bicarbonate ions. This may occur as a consequence of a loss of hydrogen ions or a gain in bicarbonate. Hydrogen ions may be lost through the kidneys or the GI tract, as for example during vomiting, nasogastric suction or use of diuretics. Intracellular shifting of hydrogen ions develops mainly during hypokalaemia to maintain neutrality. Gain in bicarbonate ions may develop during administration of sodium bicarbonate in high amounts or in amounts that exceed the capacity of excretion of the kidneys, as seen in renal failure. Fluid losses may be another cause of metabolic alkalosis, causing the reduction of extracellular fluid volume.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
-
-
Question 61
Correct
-
A 45-year-old woman was brought to the emergency department due to fever and chills. She has a history of recurrent UTI and complains of dysuria and urinary frequency. Urinary white blood cell count is >200 cell/high power field. If urine culture is performed, what is the most likely organism that will grow?
Your Answer: Escherichia coli
Explanation:The pathogen that most likely causes recurrent urinary tract infection in young women are E. coli, Enterococcus and Staphylococcus saprophyticus.
-
This question is part of the following fields:
- Microbiology
- Pathology
-
-
Question 62
Correct
-
The most likely cause of a low p(O2) in arterial blood is:
Your Answer: Hypoxic hypoxia
Explanation:Hypoxia is when the whole body or a region is deprived of adequate oxygen supply. Different types of hypoxia include the following:
– Hypoxic hypoxia, which occurs due to poor oxygen supply, as a result of low partial pressure of oxygen in arterial blood. This could be due to low partial pressure of atmospheric oxygen (e.g., at high altitude), sleep apnoea, poor ventilation because of chronic obstructive pulmonary disease or respiratory arrest, or shunts. The other types of hypoxia have a normal partial pressure of oxygen.
– Anaemic hypoxia occurs due to low total oxygen content of the blood, with a normal arterial oxygen pressure.
– Hyperaemic hypoxia occurs due to poor delivery of oxygen to target tissues, such as in carbon monoxide poisoning or methemoglobinemia.
– Histotoxic hypoxia results due to inability of the cells to use the delivered oxygen due to disabled oxidative phosphorylation enzymes.
– Ischaemic (or stagnant) hypoxia occurs due to local flow restriction of well-oxygenated blood, seen in cases like cerebral ischaemia, ischaemic heart disease and intrauterine hypoxia.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 63
Incorrect
-
Which is a feature of the action of insulin?
Your Answer:
Correct Answer: Promotes protein synthesis
Explanation:Insulin is produced by the beta-cells of the islets of Langerhans in the pancreas. Its actions include:
– promoting uptake of glucose into cells
– glycogen synthesis (glycogenesis)
– protein synthesis
– stimulation of lipogenesis (fat formation).
– driving potassium into cells – used to treat hyperkaelamia.
Parathyroid hormone and activated vitamin D are the principal hormones involved in calcium/phosphate metabolism, rather than insulin.
-
This question is part of the following fields:
- Endocrine
- Physiology
-
-
Question 64
Incorrect
-
Which of the following physiological changes will you see in a young man who has been trekking in the Himalayas for 3 years?
Your Answer:
Correct Answer: Increased renal excretion of HCO3 –
Explanation:The atmospheric pressure is lower at high altitudes as compared with sea level. This leads to a decrease in the partial pressure of oxygen. Once 2100 m (7000 feet) of altitude is reached, there is a drop in saturation of oxyhaemoglobin. The oxygen saturation of haemoglobin determines the oxygen content in the blood. The body physiological tries to adapt to high altitude by acclimatization. Immediate effects include hyperventilation, fluid loss (due to a decreased thirst drive), increase in heart rate and slightly lowered stroke volume. Long term effects include lower lactate production, compensatory alkali loss in urine, decrease in plasma volume, increased erythropoietin release and red cell mass, increased haematocrit, higher concentration of capillaries in striated muscle tissue, increase in myoglobin, increase in mitochondria, increase in aerobic enzyme concentration such as 2,3-DPG and pulmonary vasoconstriction.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 65
Incorrect
-
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:
Correct 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.
-
This question is part of the following fields:
- Pathology
- Respiratory
-
-
Question 66
Incorrect
-
Which of these HLA alleles is most likely to be present in ankylosing spondylitis?
Your Answer:
Correct Answer: HLA-B27
Explanation:Ankylosing spondylitis usually appears between the ages of 20-40 years old and is more frequent in men. It is strongly associated with HLA-B27, along with other spondyloarthropathies, which can be remembered through the mnemonic PAIR (Psoriasis, Ankylosing spondylitis, Inflammatory bowel disease, and Reactive arthritis).
-
This question is part of the following fields:
- Orthopaedics
- Pathology
-
-
Question 67
Incorrect
-
A 45-year-old man presented to the doctor complaining of a flank pain and episodes of haematuria. Abdominal ultrasound revealed a left renal mass and the patient underwent a nephrectomy. Histopathological pattern was triphasic with blastemal, epithelial, and stromal components. The pathologist suggested the tumour resulted from the lack of a tumour suppressor gene on chromosome 11. Which of the following tumours is the pathologist most likely suggesting?
Your Answer:
Correct Answer: Wilms’ tumour
Explanation:Wilms’ tumour is one of the most common malignant tumours of childhood but it can also rarely be found in adults. In biopsy, classical histopathological findings include the triphasic pattern composed by blastemal, epithelial, and stromal elements. First symptoms in children include an abdominal palpable mass, while in adults pain and haematuria are the most common complaints. Deletions of tumours’ suppressor genes on chromosome 11 are usually associated with Wilms’ tumour.
-
This question is part of the following fields:
- Pathology
- Renal
-
-
Question 68
Incorrect
-
A patient is diagnosed with Conn’s syndrome. Aldosterone is secreted from where?
Your Answer:
Correct Answer: Zona glomerulosa of the adrenal cortex
Explanation:The adrenal gland comprises an outer cortex and an inner medulla, which represent two developmentally and functionally independent endocrine glands.
The adrenal medulla secretes adrenaline (70%) and noradrenaline (30%)
The adrenal cortex consists of three layers (remembered by the mnemonic GFR):
G = zona glomerulosa – secretes aldosterone
F = zona fasciculata – secretes cortisol and sex steroids
R = zona reticularis – secretes cortisol and sex steroids.
Aldosterone facilitates the reabsorption of sodium and water and the excretion of potassium and hydrogen ions from the distal convoluted tubule and collecting ducts. Conn’s syndrome is characterized by increased aldosterone secretion from the adrenal glands.
-
This question is part of the following fields:
- Endocrine
- Physiology
-
-
Question 69
Incorrect
-
The physician suggested lifestyle modification for his patient because his present condition could increase his risk for the development of adenocarcinoma of the oesophagus. What is the most common predisposing factor for the development of adenocarcinoma of the oesophagus?
Your Answer:
Correct Answer: Gastro-oesophageal reflux disease
Explanation:Barret’s oesophagus is attributed primarily to gastro-oesophageal reflux disease. The chronic acidic environment damages the squamous epithelial lining of the oesophagus, and subsequently undifferentiated pluripotent stem cells develop into columnar epithelium, this is then known as Barret’s oesophagitis.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 70
Incorrect
-
A 25 year old women is pregnant with her second child. She is A- blood group. Her first child was Rh+ and the father is also Rh+. The second child is at a risk of developing which condition?
Your Answer:
Correct Answer: Haemolytic disease of the new-born
Explanation:This infant is at risk for haemolytic disease of the new born also known as erythroblastosis fetalis. In the pregnancy, Rh-positive RBC’s cross the placenta and enter the mothers blood system. She then becomes sensitised and forms IgG antibodies/anti-Rh antibodies against them. The second child is at a greater risk for this disease than the first child with Rh-positive blood group as during the second pregnancy, a more powerful response is produced. IgG has the ability to cross the placenta and bind to the fetal RBCs (type II hypersensitivity reaction) which are phagocytosed by the macrophages.
-
This question is part of the following fields:
- Inflammation & Immunology; Haematology
- Pathology
-
-
Question 71
Incorrect
-
Which of the following conditions may cause hypervolaemic hyponatraemia?
Your Answer:
Correct Answer: Cirrhosis
Explanation:Hypovolaemic hyponatraemia: reduced extracellular fluid
Renal loss of sodium and water; urine Na >20 mmol/day
Causes:
Diuretic use
Salt wasting nephropathy
Cerebral salt wasting
Mineralocorticoid deficiency/adrenal insufficiency
Renal tubular acidosis
Extrarenal loss of sodium and water with renal conservation; urine Na <20 mmol/day
Causes:
Burns
Gastrointestinal loss
Pancreatitis
Blood loss
3rd space loss (bowel obstruction, peritonitis)Hypervolaemic hyponatraemia: expanded intracellular fluid and extracellular fluid but reduced effective arterial blood volume
Causes:
Congestive cardiac failure
Cirrhosis
Nephrotic syndromeEuvolaemic hyponatraemia: expanded intracellular and extracellular fluid but oedema absent
Causes:
Thiazide diuretics (can be euvolaemic or hypovolaemic)
Hypothyroidism
Adrenal insufficiency (can be euvolaemic or hypovolaemic)
SIADH (cancer, central nervous system disorders, drugs, pulmonary disease, nausea, postoperative pain, HIV, infection, Guillain‐Barre syndrome, acute intermittent porphyria)
Decreased solute ingestion (beer potomania/tea and toast diet) -
This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
-
-
Question 72
Incorrect
-
A 58-year-old woman diagnosed with deep vein thrombosis had been using warfarin for 10 days. When she presented to the doctor she had haemorrhagic bullae and necrotic lesions in her lower limbs and buttocks. Deficiency of which of the following proteins may have caused the necrotic skin lesions?
Your Answer:
Correct Answer: Protein C
Explanation:Warfarin-induced skin necrosis is a rare complication of anticoagulant therapy that requires immediate drug cessation. The most common cutaneous findings include petechiae that progress to ecchymoses and haemorrhagic bullae. Warfarin inactivates vitamin K-dependent clotting factors II, VII, IX, and X and vitamin K-dependent proteins C and S. The concentration of protein C falls more rapidly than other vitamin K-dependent factors because they have a shorter half-lives. Skin necrosis is seen mainly in patients with prior protein C deficiency.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 73
Incorrect
-
If a tumour is found in both lobes of the prostate, without nodal involvement or metastases, a histological grade of G2 and elevated PSA, what is the overall prostatic cancer stage?
Your Answer:
Correct Answer: Stage II
Explanation:The AJCC uses the TNM, Gleason score and PSA levels to determine the overall stage of prostatic cancer. This staging is as follows:
Stage I: T1, N0, M0, Gleason score 6 or less, PSA less than 10; or T2a, N0, M0, Gleason score 6 or less, PSA less than 10
Stage IIa: T1, N0, M0, Gleason score of 7, PSA less than 20; or T1, N0, M0, Gleason score of 6 or less, PSA at least 10 but less than 20; or T2a or T2b, N0, M0, Gleason score of 7 or less, PSA less than 20
Stage IIb: T2c, N0, M0, any Gleason score, any PSA; or T1 or T2, N0, M0, any Gleason score PSA of 20 or more; or T1 or T2, N0, M0, Gleason score of 8 or higher, any PSA
Stage III: T3, N0, M0, any Gleason score, any PSA Stage IV: T4, N0, M0,any Gleason score, any PSA; or any T, N1, M0,any Gleason score, any PSA; or Any T, any N, M1, any Gleason score, any PSA.
The patient in this case has a T2 N0 M0 G2 tumour, meaning it belongs in stage II
-
This question is part of the following fields:
- Pathology
- Urology
-
-
Question 74
Incorrect
-
A 27 year-old male patient was admitted to the hospital due to recurrent fever for the past 2 weeks. The patient claimed that he is an intravenous drug user. Following work up, the patient was diagnosed with infective endocarditis. Which is the most likely organism responsible for this diagnosis?
Your Answer:
Correct Answer: Staphylococcus aureus
Explanation:Acute bacterial endocarditis is a fulminant illness lasting over days to weeks (<2weeks). It is most likely due to Staphylococcus aureus especially in intravenous drug abusers.
-
This question is part of the following fields:
- Microbiology
- Pathology
-
-
Question 75
Incorrect
-
The blood investigations of a 30-year old man with jaundice revealed the following : total bilirubin 6.5 mg/dl, direct bilirubin 1.1 mg/dl, indirect bilirubin 5.4 mg/dl and haemoglobin 7.3 mg/dl. What is the most likely diagnosis out of the following?
Your Answer:
Correct Answer: Haemolysis
Explanation:Hyperbilirubinemia can be caused due to increased bilirubin production, decreased liver uptake or conjugation, or decreased biliary excretion. Normal bilirubin level is less than 1.2 mg/dl (<20 μmol/l), with most of it unconjugated. Elevated unconjugated bilirubin (indirect bilirubin fraction >85%) can occur due to haemolysis (increased bilirubin production) or defective liver uptake/conjugation (Gilbert syndrome). Such increases are less than five-fold usually (<6 mg/dl or <100 μmol/l) unless there is coexistent liver disease.
-
This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
-
-
Question 76
Incorrect
-
Fine-needle aspiration is a type of biopsy procedure. When performing a fine-needle aspiration of the lungs, which is the most common complication of the procedure?
Your Answer:
Correct Answer: Pneumothorax
Explanation:Pneumothorax is the most common complication of a fine-needle aspiration procedure. Various factors, such as lesion size, have been associated with increased risk of pneumothorax .
-
This question is part of the following fields:
- Pathology
- Respiratory
-
-
Question 77
Incorrect
-
A 45 year old women has a 4 cm non tender mass in her right breast which is fixed to the chest wall. Another 2cm non-tender mass is palpable in the left axilla. Chest x ray reveals multiple nodules ranging from 0.5 - 0.2 cm in both the lungs. What is the stage of her disease?
Your Answer:
Correct Answer: T4 N1 M1
Explanation:This woman has an invasive primary tumour mass with axillary node and lung metastases, making this stage T4 N1 M1. Looking at the other stems, T1 N1 M0 signifies a small primary cancer with nodal metastases but no distant metastases; T1 N0 M1 signifies a small primary cancer with no lymph node metastases but with distant metastases; T2 N1 M0 signifies a larger primary cancer with nodal metastases but no distant metastases; and T3 N0 M0 indicates a larger primary cancer with no metastases to either lymph nodes or to distant sites.
-
This question is part of the following fields:
- Neoplasia; Female Health
- Pathology
-
-
Question 78
Incorrect
-
The accumulation of eosinophils within tissues is mostly regulated by which of the following cytokines?
Your Answer:
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.
-
This question is part of the following fields:
- Inflammation & Immunology
- Pathology
-
-
Question 79
Incorrect
-
In a study, breast lumps were analysed to determine the characteristic of malignant neoplasm on biopsy. What microscopic findings are suggestive of malignancy?
Your Answer:
Correct Answer: Invasion
Explanation:Invasion is suggestive of malignancy and an even better option would have been metastasis. Pleomorphism is found in both benign and malignant neoplasms along with atypia and anaplasia. A height nuclear/cytoplasmic ratio is suggestive of malignancy but not the best indicator. Malignant tumours are aggressive and growth rapidly. Necrosis can be seen in benign tumours if they deplete their blood supply.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 80
Incorrect
-
Urine specific gravity allows the assessment of which of the following renal functions?
Your Answer:
Correct Answer: Concentration
Explanation:Concentrating ability of kidneys is assessed by measuring the urine specific gravity. Normal values of urine specific gravity fall between 1.002 and 1.030 g/ml.
-
This question is part of the following fields:
- Pathology
- Renal
-
-
Question 81
Incorrect
-
A 32-year-old man presents to the doctor complaining of pain in his left calf whilst walking. He says that the pain goes away after a short period of rest but starts again during exercise or walking. The man reveals he has been a smoker for the last 15 years. His blood pressure, blood sugar and cholesterol level are normal. Artery biopsy shows intraluminal thrombosis and vasculitis. What's is the most likely cause of these findings?
Your Answer:
Correct Answer: Buerger's disease
Explanation:Thromboangiitis obliterans, also known as Buerger’s disease, is a rare type of occlusive peripheral arterial disease, usually seen in smokers, most commonly in men aged 20 to 40. Symptoms most often include intermittent claudication, skin changes, painful ulcers on extremities, pain in the extremities during rest and gangrene. Diagnosis is based on clinical findings, arteriography, echocardiography, and computed tomography angiography. A difference in blood pressure between arms, or between the arms and legs is a common finding. Electrocardiographic findings include nonspecific abnormality or normal results.
-
This question is part of the following fields:
- Cardiovascular
- Pathology
-
-
Question 82
Incorrect
-
Which of the following is the most likely cause of prolonged thrombin clotting time?
Your Answer:
Correct Answer: Hypofibrinogenemia
Explanation:Thrombin clotting time, also called thrombin time (TT), is test used for the investigation of possible bleeding or clotting disorders. TT reflects the conversion of fibrinogen to fibrin and it’s also very sensitive to the presence of the anticoagulant heparin. A prolonged thrombin time may indicate the presence of hypofibrinogenemia (decreased fibrinogen level ), dysfibrinogenaemia, disseminated intravascular coagulation (DIC), end stage liver disease or malnutrition.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 83
Incorrect
-
A 47-year-old male smoker, who had been self-medicating with oral steroids for the last two years due to persistent breathlessness presented to the doctor complaining of a productive cough, fever and chest pain. A chest X-ray revealed bilateral patchy opacities. He was diagnosed with bilateral bronchopneumonia. Which of these organisms is most probably causing these findings?
Your Answer:
Correct Answer: Nocardia asteroides
Explanation:Nocardia is a Gram-positive aerobic actinomycete. Several species have been identified but the most common human pathogen is Nocardia asteroides. The predominant clinical finding in the majority of patients affected by nocardiosis is pulmonary disease. Predisposing factors for pulmonary nocardiosis include leukaemia, human immunodeficiency virus (HIV) infection, organ transplantation, diabetes and receiving prolonged corticosteroids.
-
This question is part of the following fields:
- Pathology
- Respiratory
-
-
Question 84
Incorrect
-
Linezolid is an antibiotic used for the treatment of infections caused by bacteria that are resistant to other antibiotics. Which of the following organisms is most likely to be effectively treated by linezolid?
Your Answer:
Correct Answer: Methicillin-resistant Staphylococcus aureus
Explanation:Linezolid is a synthetic antibiotic used for the treatment of infections caused by multiresistant bacteria, including streptococci and methicillin-resistant Staphylococcus aureus (MRSA). Linezolid is effective against Gram-positive pathogens, notably Enterococcus faecium, S. aureus, Streptococcus agalactiae, Streptococcus pneumoniae and Streptococcus pyogenes. It has almost no effect on Gram-negative bacteria and is only bacteriostatic against most enterococci.
-
This question is part of the following fields:
- Pathology
- Pharmacology
-
-
Question 85
Incorrect
-
Loperamide is a drug used to treat diarrhoea. What is the mechanism of action of loperamide?
Your Answer:
Correct Answer: Opiate agonist
Explanation:Loperamide is an opioid-receptor agonist and acts on the mu opioid receptors in the myenteric plexus of large intestine. It works by decreasing the motility of the circular and longitudinal smooth muscles of the intestinal wall. It is often used for this purpose in gastroenteritis, inflammatory bowel disease, and short bowel syndrome.
-
This question is part of the following fields:
- Pathology
- Pharmacology
-
-
Question 86
Incorrect
-
Painful erections along with deviation of the penis to one side when erect are seen in which of the following conditions?
Your Answer:
Correct Answer: Peyronie’s disease
Explanation:Peyronie’s disease leads to development of fibrous plaques in the penile soft tissue and occurs in 1% of men, most commonly affecting white males above 40 years age. It is a connective tissue disorder named after a French surgeon, François de la Peyronie who first described it. Symptoms include pain, hard lesions on the penis, abnormal curvature of erect penis, narrowing/shortening, painful sexual intercourse and in later stages, erectile dysfunction. 30% cases report fibrosis in other elastic tissues such as Dupuytren’s contractures of the hand. There is likely a genetic predisposition as increased incidence is noted among the male relatives of an affected individual.
-
This question is part of the following fields:
- Pathology
- Urology
-
-
Question 87
Incorrect
-
A young male was diagnosed with hepatitis A, which clinically resolved in 2 weeks. What will his liver biopsy done after 6 months show?
Your Answer:
Correct Answer: Normal architecture
Explanation:Hepatitis A is the most common acute viral hepatitis, more common in children and young adults. It is caused by Hepatitis A virus, which is a single-stranded RNA picornavirus. The primary route of spread of Hepatitis A is the faecal-oral route. Consumption of contaminated raw shellfish is also a likely causative factor. The shedding of the virus in faecal matter occurs before the onset of symptoms and continues a few days after. Hepatitis A does not lead to chronic hepatitis or cirrhosis, and there is no known chronic carrier state. Hence, a biopsy performed after recovery will show normal hepatocellular architecture.
-
This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
-
-
Question 88
Incorrect
-
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:
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.
-
This question is part of the following fields:
- Orthopaedics
- Pathology
-
-
Question 89
Incorrect
-
The blood-brain barrier is a membrane that separates the circulating blood from the brain extracellular fluid in the central nervous system (CNS). Which of the following statements regarding the blood– brain barrier is CORRECT?
Your Answer:
Correct Answer: It breaks down in areas of brain that are infected
Explanation:The blood–brain barrier is a membrane that controls the passage of substances from the blood into the central nervous system. It is a physical barrier between the local blood vessels and most parts of the central nervous system and stops many substances from travelling across it. During meningitis, the blood–brain barrier may be disrupted. This disruption may increase the penetration of various substances (including either toxins or antibiotics) into the brain. A few regions in the brain, including the circumventricular organs, do not have a blood–brain barrier.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 90
Incorrect
-
A 47-year old-woman diagnosed with pancreatitis presented to the emergency department complaining of a worsening shortness of breath, fever, agitation and cough. Oxygen saturation was 67% in room air. Her respiratory status continued to deteriorate therefore she was intubated. She was admitted to the intensive care unit for management. Chest X-ray demonstrated bilateral perihilar opacities. The patient failed conventional treatment and died several days later. At autopsy, the lung shows growth of type 2 pneumocytes and thickened alveolar walls. What is the most probable diagnosis?
Your Answer:
Correct Answer: Adult respiratory distress syndrome
Explanation:Acute (or adult) respiratory distress syndrome (ARDS) is a life-threatening lung condition characterised by a non-cardiogenic pulmonary oedema that leads to acute respiratory failure. The most common risk factors for ARDS include trauma with direct lung injury, sepsis, pneumonia, pancreatitis, burns, drug overdose, massive blood transfusion and shock. Acute onset of dyspnoea with hypoxemia, anxiety and agitation is typical. Chest X ray most commonly demonstrates bilateral pulmonary infiltrates. Histological changes include the exudative, proliferative and fibrotic phase. ARDS is mainly a clinical diagnosis.
-
This question is part of the following fields:
- Pathology
- Respiratory
-
-
Question 91
Incorrect
-
A 13-year-old girl has complained of pain in her left arm for 4 months. An X-ray reveals a mass along with erosion of the affected humerus. Histologically, the tumour is found to be formed by small, round, blue cells. What is the most likely diagnosis?
Your Answer:
Correct Answer: Ewing’s sarcoma
Explanation:Ewing’s sarcoma is formed by small, round, blue cells, and is common in children. The usually develop in limbs, and clinical findings include pain and inflammation, with lytic destruction showing up on X-rays.
-
This question is part of the following fields:
- Orthopaedics
- Pathology
-
-
Question 92
Incorrect
-
A 45-year-old man presents to the emergency department with an irregular pulse and shortness of breath. Electrocardiography findings show no P waves, normal QRS complexes and an irregularly irregular rhythm. The patient most probably has:
Your Answer:
Correct Answer: Atrial fibrillation
Explanation:Atrial fibrillation is one of the most common arrhythmias, characterised by an irregular and rapid heart rate. Due to the decreased cardiac output, atrial fibrillation increases the risk of heart failure. It can also lead to thrombus formation which may lead to thromboembolic events. Clinical findings include palpitations, shortness of breath, fatigue, chest pain and confusion. The diagnosis is made by electrocardiographic findings which include absent P wave, fibrillatory (f) waves between QRS complexes and irregularly irregular R-R intervals.
-
This question is part of the following fields:
- Cardiovascular
- Pathology
-
-
Question 93
Incorrect
-
What is the most likely cause of bilateral gynaecomastia in a 55-year old male?
Your Answer:
Correct Answer: Hepatic failure
Explanation:Hypertrophy of breast tissue in males is known as gynaecomastia. It is normally due to proliferation of stroma and not of mammary ducts. Physiological gynaecomastia can occur during puberty and is often transient, bilateral, symmetrical and possibly tender. Gynaecomastia can occur during old age too, but is usually unilateral. Other causes include hepatic or renal failure, endocrinological disorders, drugs (anabolic steroids, antineoplastic drugs, calcium channel blockers, cimetidine, digitalis, oestrogens, isoniazid, ketoconazole, methadone, metronidazole, reserpine, spironolactone, theophylline), and marijuana. It should not be confused with malignancy which is often hard, asymmetric and fixed to the dermis or fascia. Treatment if indicated, includes withdrawal of the causative factor or treatment of the underlying disorder.
-
This question is part of the following fields:
- Pathology
- Women's Health
-
-
Question 94
Incorrect
-
An experiment is carried out to observe engulfment and phagocytosis of microbes. Strep pneumoniae are added to a solution of leukocytes with a substance added to enhance the process of phagocytosis. What is this substance?
Your Answer:
Correct Answer: Complement C3b
Explanation:C3b is cleaved from C3 complement with the help of the enzyme C3- convertase. It binds to the cell surface of the offending substance and opsonizes it. This makes it easy for the phagocytes to detect and eliminate them.
IgM does not act as an opsonin but igG does.
Selectins aid leukocytes to bind to the endothelial surfaces.
C5a is a chemo-attractant and histamine a vasodilator.
NADPH oxidises offending substance after phagocytosis within the macrophage.
-
This question is part of the following fields:
- Inflammation & Immunology
- Pathology
-
-
Question 95
Incorrect
-
A chest X-ray in a healthy, non-smoker, asymptomatic 48-year-old woman reveals a 2cm left lower lobe well-defined round opacity. Which of the following conditions is most probably responsible for this finding?
Your Answer:
Correct Answer: Pulmonary hamartoma
Explanation:An asymptomatic healthy patient with no history of smoking and a lesion of small size most probably has a benign lung lesion. Hamartomas are one of the most common benign tumours of the lung that accounts for approximately 6% of all solitary pulmonary nodules. Pulmonary hamartomas are usually asymptomatic and therefore are found incidentally when performing an imaging test for other reasons.
-
This question is part of the following fields:
- Pathology
- Respiratory
-
-
Question 96
Incorrect
-
The pleural cavity is the space between the two pulmonary pleurae which cover the lungs. What is the normal amount of pleural fluid?
Your Answer:
Correct Answer: 10 ml
Explanation:Pleural fluid is a serous fluid produced by the serous membrane covering normal pleurae. Most fluid is produced by the parietal circulation (intercostal arteries) via bulk flow and reabsorbed by the lymphatic system. The total volume of fluid present in the intrapleural space is estimated to be only 2–10 ml. A small amount of protein is present in intrapleural fluid. Normally, the rate of reabsorption increases as a physiological response to accumulating fluid.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 97
Incorrect
-
Which of the following diseases causes abrupt vertigo, nausea, vomiting, tinnitus, and nystagmus?
Your Answer:
Correct Answer: Vestibular neuronitis
Explanation:Vestibular neuronitis or labyrinthitis causes a self-limited episode of vertigo, presumably due to inflammation of the vestibular division of cranial nerve VIII. Its causes are unknown, It may be due to a virus, but it can be related to a bacterial infection, head injury, stress, allergy, or as a reaction to medication. Symptoms can last up to 7-10 days.
-
This question is part of the following fields:
- Neurology
- Pathology
-
-
Question 98
Incorrect
-
A 65-year old gentleman presents to the clinic with chronic back pain and weight loss. His blood count shows a white blood cell count of 10 × 109/l, with a differential count of 66 polymorphonuclear leukocytes, 7 bands, 3 metamyelocytes, 3 myelocytes, 14 lymphocytes, 7 monocytes, and 5 nucleated red blood cells. The haemoglobin is 13 g/dl with a haematocrit of 38.1%, a mean corpuscular volume of 82 fl, and a platelet count of 126 × 109/l. What is the likely diagnosis?
Your Answer:
Correct Answer: Metastatic carcinoma
Explanation:The peripheral blood findings suggest a leucoerythroblastic picture, the common causes of which in a 65-year old gentleman includes prostatic or lung malignancy.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 99
Incorrect
-
A 62-year-old male patient in the intensive care unit was found to have a low serum phosphate level. What is the serum level of phosphate which is considered as normal in adults?
Your Answer:
Correct Answer: 0.8–1.45 mmol/l
Explanation:After calcium, phosphorus is the most plentiful mineral in the human body. It is an important and vital element which our body needs to complete many physiologic processes , such as filtering waste and repairing cells. Phosphorus helps with bone growth and approximately 85% of phosphate in the body is contained in bone. Phosphate is involved in energy storage, and nerve and muscle production. A normal range of plasma phosphate in adults teenagers generally from 0.8 mmol/l to 1.45 mmol/l. The normal range varies depending on age. Infants and children have higher phosphorus levels because more of this mineral is needed for their normal growth and bone development.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
-
-
Question 100
Incorrect
-
A 22-year old man presented with a mass in his left scrotum which was more prominent when standing and felt like a 'bag of worms'. Examination revealed a non-tender mass along the spermatic cord. Also, the right testis was larger than the left testis. What is the likely diagnosis?
Your Answer:
Correct Answer: Varicocele
Explanation:Varicocele refers to dilatation and increased tortuosity of the pampiniform plexus – which is a network of veins found in spermatic cord that drain the testicle. Defective valves or extrinsic compression can result in outflow obstruction and cause dilatation near the testis. Normal diameter of the small vessels ranges from 0.5 – 1.5mm. A varicocele is a dilatation more than 2mm.
The plexus travels from the posterior aspect of testis into the inguinal canal with other structures forming the spermatic cord. They then form the testicular veins out of which the right testicular vein drains into the inferior vena cava and the left into the left renal vein.
It affects 15-20% men, and 40% of infertile males. Usually diagnosed in 15-25 years of age, they are rarely seen after 40 years of age. Because of the vertical path taken by the left testicular vein to drain into left renal vein, 98% idiopathic varicoceles occur on the left side. It is bilateral in 70% cases. Right-sided varicoceles are rare.
Symptoms include pain or heaviness in the testis, infertility, testicular atrophy, a palpable mass, which is non-tender and along the spermatic cord (resembling a ‘bag of worms’). The testis on the affected side might be smaller.
Diagnosis can be made by ultrasound. Provocative measures such as Valsalva manoeuvre or making the patient stand up to increase the dilatation by increasing the intra-abdominal venous pressure.
-
This question is part of the following fields:
- Pathology
- Urology
-
-
Question 101
Incorrect
-
An organ transplant patient may be at risk of developing which type of cancer?
Your Answer:
Correct Answer: Skin cancer
Explanation:The most common malignancies encountered in the post–solid organ transplant setting are non-melanoma skin cancers, post-transplant lymphoproliferative disorders and Kaposi’s sarcoma (KS). The pathogenesis of these tumours is likely related to the immunosuppressive drugs used post-transplantation and subsequent viral infection.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 102
Incorrect
-
As per the Poiseuille-Hagen formula, doubling the diameter of a vessel will change the resistance of the vessel from 16 peripheral resistance units (PRU) to:
Your Answer:
Correct Answer: 1 PRU
Explanation:Poiseuille-Hagen formula for flow in along narrow tube states that F = (PA– PB) × (Π/8) × (1/η) × (r4/l) where F = flow, PA– PB = pressure difference between the two ends of the tube, η = viscosity, r = radius of tube and L = length of tube. Also, flow is given by pressure difference divided by resistance. Hence, R = 8ηL ÷ Πr4. Hence, the resistance of the vessel changes in inverse proportion to the fourth power of the diameter. So, if the diameter of the vessel is increased to twice the original, it will lead to decrease in resistance to one-sixteenth its initial value.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 103
Incorrect
-
Which of the following morphological characteristic is a salient feature of a pure apoptotic cell?
Your Answer:
Correct Answer: Chromatin condensation
Explanation:Apoptosis is the programmed death of cells which occurs as a normal and controlled part of an organism’s growth or development. The changes which occur in this process include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, chromosomal DNA fragmentation, and global mRNA decay. The cell membrane however remains intact and the dead cells are phagocytosed prior to any content leakage and thus inflammatory response.
-
This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
-
-
Question 104
Incorrect
-
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:
Correct 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.
-
This question is part of the following fields:
- Microbiology
- Pathology
-
-
Question 105
Incorrect
-
Out of the following options, which malignancy has the highest potential for multicentricity?
Your Answer:
Correct Answer: Transitional cell carcinoma
Explanation:Transitional cell carcinomas can arise anywhere in the urothelium lining the urinary tract; and hence are known to be multicentric and recur commonly. Prostatic adenocarcinoma most commonly involves the posterior lobe of the prostate gland. Although renal cell carcinomas occasionally show multicentricity, it is not common. Penile carcinomas are usually locally infiltrative lesions. Wilm’s tumours are usually solitary, but can be bilateral or multicentric in 10% cases. Small cell carcinoma of lung and teratomas are usually solitary.
-
This question is part of the following fields:
- Pathology
- Renal
-
-
Question 106
Incorrect
-
Which part of the nephron would have to be damaged to stop the reabsorption of the majority of salt and water?
Your Answer:
Correct Answer: Proximal tubule
Explanation:The proximal tubule is the portion of the duct system of the nephron of the kidney which leads from Bowman’s capsule to the loop of Henle. It is conventionally divided into the proximal convoluted tubule (PCT) and the proximal straight tubule (PST). The proximal tubule reabsorbs the majority (about two-thirds) of filtered salt and water. This is done in an essentially iso-osmotic manner. Both the luminal salt concentration and the luminal osmolality remain constant (and equal to plasma values) along the entire length of the proximal tubule. Water and salt are reabsorbed proportionally because the water is dependent on and coupled with the active reabsorption of Na+. The water permeability of the proximal tubule is high and therefore a significant transepithelial osmotic gradient is not possible.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 107
Incorrect
-
A 45-year old man presents with sclerosing cholangitis, blood in his stools and apparent iron deficiency anaemia. What will be the most likely finding on his colonic biopsy?
Your Answer:
Correct Answer: Pseudopolyps
Explanation:Sclerosing cholangitis along with the passage of blood in stools suggests ulcerative colitis affecting the mucosa and submucosa of rectum and colon, with a sharp demarcation with the normal tissue. The musclaris layer is involved in severe cases. Initially, the mucosa is erythematous, friable with scattered haemorrhagic areas and loss of normal vascular pattern. Severe disease is indicated by presence of large mucosal ulcers with purulent exudate. There can be islands of normal mucosa between the ulcerated mucosa, along with few hyperplastic inflammatory mucosal lesions (pseudopolyps). Ulcerative colitis does not lead to development of fistulas or abscesses.
-
This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
-
-
Question 108
Incorrect
-
A 58-year-old woman presents with signs of inflammation in the first metatarsophalangeal joint: redness, swelling and pain. The analysis of synovial fluid reveals needle-shaped, strongly negatively birefringent crystals. What's the most likely diagnosis in this case?
Your Answer:
Correct Answer: Gout
Explanation:Gout is a rheumatic disease caused by the precipitation of monosodium urate crystals into tissues, usually joints. This causes acute or chronic pain; the acute illness initially affects only one joint, often the first metatarsophalangeal joint. The diagnosis of the disease requires the identification of crystal in the synovial fluid. These crystals are needle-shaped and strongly negatively birefringent.
-
This question is part of the following fields:
- Orthopaedics
- Pathology
-
-
Question 109
Incorrect
-
A 12-year old girl was brought to the hospital with recurrent headaches for 6 months. Her physical examination revealed no abnormality. A CT scan of the head revealed a suprasellar mass with calcifications, eroding the surrounding sella turcica. The lesion is likely to represent:
Your Answer:
Correct Answer: Craniopharyngioma
Explanation:Craniopharyngiomas (also known as Rathke pouch tumours, adamantinomas or hypophyseal duct tumours) affect children mainly between the age of 5 and 10 years. It constitutes 9% of brain tumours affecting the paediatric population. These are slow-growing tumours which can also be cystic, and arise from the pituitary stalk, specifically the nests of epithelium derived from Rathke’s pouch. Histologically, this tumour shows nests of squamous epithelium which is lined on the outside by radially arranged cells. Calcium deposition is often seen with a papillary type of architecture.
ACTH-secreting pituitary adenomas are rare and mostly microadenomas. Paediatric astrocytoma’s usually occur in the posterior fossa. Although null cell adenomas can cause mass effect and give rise to the described symptoms, they are not suprasellar. Prolactinomas can also show symptoms of headache and disturbances in the visual field, however they are known to be small and slow-growing.
-
This question is part of the following fields:
- Endocrine
- Pathology
-
-
Question 110
Incorrect
-
A 35-year-old ultra marathon runner becomes severely dehydrated and collapses. This patient most likely has:
Your Answer:
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.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 111
Incorrect
-
A 17-year-old boy, who had developed shortness of breath and a loss of appetite over the last month, was referred to a haematologist because he presented with easy bruising and petechiae. His prothrombin time, platelet count, partial thromboplastin and bleeding time were all normal. Which of the following would explain the presence of the petechiae and easy bruising tendency?
Your Answer:
Correct Answer: Scurvy
Explanation:Scurvy is a condition caused by a dietary deficiency of vitamin C, also known as ascorbic acid. Humans are unable to synthesize vitamin C, therefore the quantity of it that the body needs has to come from the diet. The presence of an adequate quantity of vitamin C is required for normal collagen synthesis. In scurvy bleeding tendency is due to capillary fragility and not coagulation defects, therefore blood tests are normal.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 112
Incorrect
-
A patient with this condition has extracellular fluid volume expansion:
Your Answer:
Correct Answer: Nephrotic syndrome
Explanation:Nephrotic syndrome is a syndrome comprising of signs of nephrosis, including proteinuria, hypoalbuminemia, and oedema. It is a component of glomerulonephritis, in which different degrees of proteinuria occur. Essentially, loss of protein through the kidneys leads to low protein levels in the blood , which causes water to be drawn into soft tissues (oedema). Severe hypoalbuminemia can also cause a variety of secondary problems, such as water in the abdominal cavity (ascites), around the heart or lung (pericardial effusion, pleural effusion), high cholesterol, loss of molecules regulating coagulation (hence increased risk of thrombosis). The most common sign is excess fluid in the body due to the serum hypoalbuminemia. Lower serum oncotic pressure causes fluid to accumulate in the interstitial tissues. Sodium and water retention aggravates the oedema.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
-
-
Question 113
Incorrect
-
Different portions of the renal tubule have varying degrees of water permeability. Which of the following renal sites is characterised by low water permeability under normal circumstances?
Your Answer:
Correct Answer: Thick ascending limb of the loop of Henlé
Explanation:Within the nephron of the kidney, the ascending limb of the loop of Henle is a segment of the loop of Henle downstream of the descending limb, after the sharp bend of the loop. Both the thin and the thick ascending limbs of the loop of Henlé have very low permeability to water. Since there are no regulatory mechanisms to alter its permeability, it remains poorly permeable to water under all circumstances. Sodium and chloride are transported out of the luminal fluid into the surrounding interstitial spaces, where they are reabsorbed. Water must remain behind because it is not reabsorbed, so the solute concentration becomes less and less (the luminal fluid becomes more dilute). This is one of the principal mechanisms (along with diminution of ADH secretion) for the production of a dilute, hypo-osmotic urine (water diuresis).
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 114
Incorrect
-
Which of the following conditions is likely to result in splenomegaly, hypochromic anaemia and hemochromatosis in a young male?
Your Answer:
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.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 115
Incorrect
-
Difficulty in retracting the foreskin of the penis in an uncircumcised male is known as:
Your Answer:
Correct Answer: Phimosis
Explanation:Phimosis is the inability to fully retract the foreskin of the penis in an uncircumcised male. It can be physiological in infancy, in which it could be referred to as ‘developmental non-retractility of the foreskin. However, it is almost always pathological in older children and men. Causes include chronic inflammation (e.g. balanoposthitis), multiple catheterisations, or forceful foreskin retraction. One of the causes is chronic balanitis xerotica obliterans. It leads to development of a ring of indurated tissue near the tip of the prepuce, which prevents retraction. Contributory factors include infections, hormonal and inflammatory factors. The recommended treatment includes circumcision.
-
This question is part of the following fields:
- Pathology
- Urology
-
-
Question 116
Incorrect
-
A histological examination of a lump showed an abnormal amount and arrangement of normal tissue in an otherwise normal area. This condition is known as?
Your Answer:
Correct Answer: Hamartoma
Explanation:A hamartoma is a condition best described as tissue normally present in an area arranged haphazardly in an disorganized, abnormal fashion. They are never malignant and do not metastasis.
All the neoplastic, cancerous lesions comprise of a mixture of different cells that are not normal to that area.
Metaplasia is a change in the type of the epithelium.
-
This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
-
-
Question 117
Incorrect
-
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:
Correct 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
-
This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
-
-
Question 118
Incorrect
-
Which of the following proteins acts as cofactor in the thrombin-induced activation of anticoagulant protein C?
Your Answer:
Correct Answer: Thrombomodulin
Explanation:Thrombomodulin is a protein cofactor expressed on the surface of endothelial cells. Thrombomodulin binds with thrombin forming a complex which activates protein C, initiating the anticoagulant pathway.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 119
Incorrect
-
Which of the given options best describes the metabolic changes which occur following a severe soft tissue injury sustained after a PVA?
Your Answer:
Correct Answer: Mobilisation of fat stores
Explanation:The following metabolic responses occur following trauma as part of a coping mechanism for the additional stress. These include acid base changes (metabolic acidosis or alkalosis), decrease urine output and osmolality, reduced basal metabolic rate (BMR), gluconeogenesis with amino acid breakdown and shunting, hyponatraemia as a result of impaired functioning of sodium pumps, hypoxic injury, coagulopathies, decreased immunity, increase extracellular fluid and hypovolemic shock, increase permeability leading to oedema, break down and mobilization of fat reserves, pyrexia and reduced circulating levels of albumin.
-
This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
-
-
Question 120
Incorrect
-
Which cells are most commonly seen in a granulomatous lesion that suggests an underlying chronic inflammation?
Your Answer:
Correct 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.
-
This question is part of the following fields:
- Inflammation & Immunology
- Pathology
-
-
Question 121
Incorrect
-
Which of the following mediators of inflammation requires arachidonic acid for synthesis?
Your Answer:
Correct Answer: Prostaglandins
Explanation:Arachidonic acid is normally present in the phospholipids that make up the cell membrane and is cleaved by phospholipase A2 from the phospholipid. Arachidonic acid is a precursor for the production of eicosanoids which include: 1) prostaglandins, prostacyclins and thromboxane, 2) leukotrienes and 3) anandamides. The production of these products along with their action on the body is called the arachidonic acid cascade.
-
This question is part of the following fields:
- Inflammation & Immunology
- Pathology
-
-
Question 122
Incorrect
-
A 45 year-old male, with behavioural changes developed euvolemic hyponatraemia. Which of the following conditions most likely predisposed the patient to develop euvolemic hyponatraemia?
Your Answer:
Correct Answer: Psychosis
Explanation:In euvolemic hyponatraemia, there is volume expansion in the body, there is no oedema, but hyponatremia occurs. Causes include: state of severe pain or nausea, psychosis, brain trauma, SIADH, hypothyroidism and glucocorticoid deficiency.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
-
-
Question 123
Incorrect
-
An ECG of a 30 year old woman revealed low voltage QRS complexes. This patient is most probably suffering from?
Your Answer:
Correct 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.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 124
Incorrect
-
A 5 year-old-child with fever complains of sore throat . She was brought to her paediatrician for consult because she has also developed a rash and has swollen lymph nodes. Upon physical examination she cried when her liver was palpated and the tip of her spleen is slightly palpable. Full blood count shows haemoglobin 13 g/dL, Haematocrit 40%, white blood cell count 13x109/L with a WBC differential count of 45 neutrophils, 4 bands, 26 lymphocytes, 15 atypical lymphocytesm, 10 monocytes and 1 eosinophil. Whick is the most likely infectious agent that is responsible for the patient's condition?
Your Answer:
Correct Answer: Epstein–Barr virus
Explanation:Epstein-Barr virus (EBV), also known as human herpes virus 4,is a member of the herpes virus family. EBV spreads most commonly through bodily fluids, primarily saliva. EBV can cause infectious mononucleosis. Symptoms of EBV can include fatigue, fever, inflamed throat, swollen lymph nodes in the neck, enlarged spleen, swollen liver and rash.
-
This question is part of the following fields:
- Microbiology
- Pathology
-
-
Question 125
Incorrect
-
The most important difference between interstitial fluid and plasma is the:
Your Answer:
Correct Answer: Protein concentration
Explanation:Interstitial fluid (or tissue fluid or intercellular fluid) is a solution that surrounds the cells of multicellular animals. It is the main component of the extracellular fluid, which also includes plasma, lymph and transcellular fluid. Plasma, the major component in blood, communicates freely with interstitial fluid through pores and intercellular clefts in capillary endothelium. Interstitial fluid consists of a water solvent containing amino acids, sugars, fatty acids, coenzymes, hormones, neurotransmitters, salts, as well as waste products from the cells. Red blood cells, platelets and plasma proteins cannot pass through the walls of the capillaries. The resulting mixture that does pass through is essentially blood plasma without the plasma proteins. Tissue fluid also contains certain types of white blood cells. Once the extracellular fluid collects into small vessels it is considered to be lymph, and the vessels that carry it back to the blood are called the lymphatic vessels. The lymphatic system returns protein and excess interstitial fluid to the circulation.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 126
Incorrect
-
Decreased velocity of impulse conduction through the atrioventricular node (AV node) in the heart will lead to:
Your Answer:
Correct Answer: Increased PR interval
Explanation:AV node damage may lead to an increase in the PR interval to as high as 0.25 – 0.40 s (normal = 0.12 – 0.20 s). In the case of severe impairment, there might be a complete failure of passage of impulses leading to complete block. In this case, the atria and ventricles will beat independently of each other.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 127
Incorrect
-
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:
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).
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 128
Incorrect
-
What percentage of the cardiac output is delivered to the brain?
Your Answer:
Correct Answer: 15%
Explanation:Among all body organs, the brain is most susceptible to ischaemia. Comprising of only 2.5% of total body weight, the brain receives 15% of the cardiac output. Oxygen extraction is also higher with venous oxygen levels approximating 13 vol%, and arteriovenous oxygen difference of 7 vol%.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 129
Incorrect
-
Macrolides are a group of antibiotics commonly used to treat respiratory tract and soft-tissue infections. Which of the following antibiotics is a macrolide?
Your Answer:
Correct Answer: Erythromycin
Explanation:Erythromycin is a macrolide antibiotic used in the treatment of several bacterial infections, including respiratory tract infections, skin infections, chlamydia infections, pelvic inflammatory disease, and syphilis. It may also be used during pregnancy to prevent Group B streptococcal infection in the new-born.
-
This question is part of the following fields:
- Pathology
- Pharmacology
-
-
Question 130
Incorrect
-
Multiple, non-tender lymphadenopathy with biopsy showing several crowded follicles of small, monomorphic lymphocytes and the absence of Reed-Sternberg cells is seen in which of the following?
Your Answer:
Correct Answer: Poorly differentiated lymphocytic lymphoma
Explanation:Malignant lymphoma usually causes non-tender lymphadenopathy, unlike the tender lymphadenopathy caused by infections (including infectious mononucleosis caused by Epstein-Barr virus). Also, the lymphoid hyperplasia seen in infectious mononucleosis is benign and polyclonal.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 131
Incorrect
-
A 72 year old man suffered a MI. What is the approximate time needed by the scar tissue of the MI to recover and attain full strength?
Your Answer:
Correct Answer: Several months
Explanation:A week following a MI attack, a little collagen starts to form and deposit. By the end of the 2nd week, neovascularisation of the scar occurs, with some collagen being laid down in a haphazard fashion. By this time the scar attains some strength. During the next 6 months, collagen is constantly being laid down and is rearranged in order to shrink the scar. Most of the blood vessels by this time have regenerated, decreasing vascularity of the scar reaching full maturity.
-
This question is part of the following fields:
- Cell Injury & Wound Healing; Cardiovascular
- Pathology
-
-
Question 132
Incorrect
-
A 25-year-old woman complains of generalised swelling and particularly puffiness around the eyes which is worst in the morning. Laboratory studies showed:
Blood urea nitrogen (BUN) = 30 mg/dl
Creatinine = 2. 8 mg/dl
Albumin = 2. 0 mg/dl
Alanine transaminase (ALT) = 25 U/l
Bilirubin = 1 mg/dl
Urine analysis shows 3+ albumin and no cells.
Which of the following is the most likely diagnosis?Your Answer:
Correct Answer: Nephrotic syndrome
Explanation:Nephrotic syndrome is a disorder in which the glomeruli have been damaged, characterized by:
– Proteinuria (>3.5 g per 1.73 m2 body surface area per day, or > 40 mg per square meter body surface area per hour in children)
– Hypoalbuminemia (< 2,5 g/dl) – Hyperlipidaemia, and oedema (generalized anasarca).
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 133
Incorrect
-
A 50-year old lady presented to the clinic with chronic pain in the abdomen. On physical examination, she was found to be pale. Further investigations revealed a decrease in both serum iron and total iron-binding capacity, along with an increase in serum ferritin. These findings are seen in:
Your Answer:
Correct Answer: Anaemia of chronic disease
Explanation:Anaemia of chronic disease is characterized by low serum iron, iron-binding capacity and saturation with increased ferritin (storage iron). Haemolytic anaemia is characterized by normal iron levels as the haemoglobin released from the haemolysed red blood cells is recycled. Anaemia due to chronic blood loss leads to low serum iron, low ferritin and high total iron-binding capacity (TIBC). Malabsorption, especially with duodenal involvement can also lead to iron deficiency anaemia with low ferritin and high TIBC. Megaloblastic anaemia due to vitamin B12 and folate deficiency is not associated with abnormalities in metabolism of iron.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 134
Incorrect
-
Hormones of the anterior pituitary include which of the following?
Your Answer:
Correct Answer: Prolactin
Explanation:The anterior pituitary gland (adenohypophysis or pars distalis) synthesizes and secretes:
1. FSH (follicle-stimulating hormone)
2. LH (luteinizing hormone)
3. Growth hormone
4. Prolactin
5. ACTH (adrenocorticotropic hormone)
6. TSH (thyroid-stimulating hormone).
The posterior pituitary gland (neurohypophysis) stores and secretes 2 hormones produced by the hypothalamus:
1. ADH (antidiuretic hormone or vasopressin)
2. Oxytocin
-
This question is part of the following fields:
- Endocrine
- Physiology
-
-
Question 135
Incorrect
-
A 75-year old patient is in atrial fibrallation but has never been on anticoagulation therapy. To reduce the risk of future emboli, she would benefit from starting on long-term warfarin. Arterial emboli leading to acute limb ischaemia most commonly lodge at which one of the following sites?
Your Answer:
Correct Answer: Common femoral artery
Explanation:The common femoral artery is the commonest site of arterial emboli causing acute limb ischemia. The treatment of choice is urgent femoral embolectomy.
-
This question is part of the following fields:
- Cardiovascular
- Pathology
-
-
Question 136
Incorrect
-
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:
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.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 137
Incorrect
-
A 30-year-old female was alarmed when she started to experience hair loss and balding, however, she also noted increased hair on her face and body and developed an acne breakout. Deepening of her voice also became prominent. She was referred to an oncologist and was diagnosed with a hormone-producing tumour. What is the most likely diagnosis ?
Your Answer:
Correct Answer: Arrhenoblastoma
Explanation:Arrhenoblastoma, known as ‘Sertoli–Leydig tumour’ is a rare ovarian stromal neoplasm that secretes testosterone. It is mostly seen in women in the reproductive years. The key clinical features of this tumour is due to excessive production of testosterone which leads to progressive masculinisation in a woman who was typical normal beforehand. The lesion tends to grow slowly and rarely metastasises. Treatment is surgical removal of the tumour and the prognosis is generally good.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 138
Incorrect
-
Langhans giant cells are characteristically seen in which type of inflammation?
Your Answer:
Correct Answer: Granulomatous inflammation
Explanation:Langhans giant cells are characteristically seen in granulomatous inflammation. They form when epithelioid cells fuse together. They usually contain a nuclei with a horseshoe-shaped pattern in the periphery of the cell.
-
This question is part of the following fields:
- Inflammation & Immunology
- Pathology
-
-
Question 139
Incorrect
-
A 7-year-old boy with facial oedema was brought to the hospital by his parents. Renal function is normal and urinalysis revealed the presence of a profound proteinuria. Which of the following is the most probable cause of these findings?
Your Answer:
Correct Answer: Minimal-change disease
Explanation:Minimal-change disease (MCD) refers to a histopathologic glomerular lesion, typically found in children, that is almost always associated with nephrotic syndrome. The most noticeable symptom of MCD is oedema, which can develop very rapidly. Due to the renal loss of proteins muscle wasting and growth failure may be seen in children. Renal function is usually not affected and a proteinuria of more than 40 mg/h/m2 is the only abnormal finding in urinalysis.
-
This question is part of the following fields:
- Pathology
- Renal
-
-
Question 140
Incorrect
-
Gram positive bacteria differ from gram negative bacteria due to the presence of which of the following structures?
Your Answer:
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.
-
This question is part of the following fields:
- Microbiology
- Pathology
-
-
Question 141
Incorrect
-
The periphery of a haematoma is infiltrated by fibroblasts, collagen and new vasculature. This process is best described as?
Your Answer:
Correct Answer: Organisation of the haematoma
Explanation:Formation of granulation tissue at the periphery of the hematoma is a normal process leading to resolution. This granulation tissue is composed of new capillaries, fibroblasts and collagen. Lysis of a blood clot can occur, but the actual process of this response is known as organization, wherein the scar tissue will become part of the vessels. This is followed by recanalization and embolization which can lead to eventual complications. Proliferation of a clot will occur due to an imbalance in the clotting and lysing systems. Thrombosis has nothing to do with the process described above.
-
This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
-
-
Question 142
Incorrect
-
A 45-year old male, who was a chronic smoker presented to the clinic with backache and dry, incessant cough. On examination, he was found to have raised blood pressure, purplish striae on his abdomen, truncal obesity and tenderness over the lower thoracic spine. These findings are suggestive of which condition?
Your Answer:
Correct Answer: Small-cell anaplastic (oat cell) carcinoma
Explanation:The symptoms suggest Cushing syndrome due to increased glucocorticoid levels. One cause of Cushing syndrome is ectopic production of adrenocorticotrophic hormone from oat cell carcinoma. As oat cell carcinoma is known to be highly metastatic, the tenderness in lower back could represent metastatic involvement.
-
This question is part of the following fields:
- Endocrine
- Pathology
-
-
Question 143
Incorrect
-
Chronic obstructive pulmonary disease (COPD) is likely to result in:
Your Answer:
Correct Answer: Respiratory acidosis
Explanation:COPD leads to respiratory acidosis (chronic). This occurs due to hypoventilation which involves multiple causes, such as poor responsiveness to hypoxia and hypercapnia, increased ventilation/perfusion mismatch leading to increased dead space ventilation and decreased diaphragm function.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 144
Incorrect
-
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:
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.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 145
Incorrect
-
A patient is suspected to have Blastomyces dermatidis infection. The patient contracted the disease most likely through which port of entry?
Your Answer:
Correct Answer: Respiratory tract
Explanation:Blastomycosis disease is a fungal infection acquired through inhalation of the spores. It caused by the organism Blastomyces dermatitidis and manifests as a primary lung infection in about 70% of cases. The onset is relatively slow and symptoms are suggestive of pneumonia.
-
This question is part of the following fields:
- Microbiology
- Pathology
-
-
Question 146
Incorrect
-
A middle aged man presented in OPD with a low grade fever and a persistent cough. His blood smear showed an increase in cells with large bi-lobed nuclei. Which of these cells represent the one seen on the smear?
Your Answer:
Correct Answer: Monocytes
Explanation:Monocytes are white cells that protect the body against harmful pathogens. They are mobile and are produced in the bone marrow, mature there and circulate in the blood for about 1-3 days, where they enter the tissues and transform into macrophages. They are characteristically identified by their large bi-lobed nuclei.
-
This question is part of the following fields:
- Inflammation & Immunology
- Pathology
-
-
Question 147
Incorrect
-
A patient with this type of tumour is advised to follow up regularly for monitoring of tumour size as there is a strong correlation with malignant potential and tumour size. Which of the following is the most likely tumour in this patient?
Your Answer:
Correct Answer: Renal adenocarcinoma
Explanation:The distinction between a benign renal adenoma and renal adenocarcinoma is commonly made on the basis of size. Tumours less than 2 cm in size rarely become malignant as opposed to those greater than 3 cm.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 148
Incorrect
-
A 34-year-old Asian male presents with cervical lymphadenopathy. The patient is suspected to have tuberculous lymphadenopathy. Excision biopsy of one of the nodes showed granulomatous inflammation. Which histopathologic feature is most likely consistent with the diagnosis of tuberculosis?
Your Answer:
Correct Answer: Caseation necrosis
Explanation:The granulomas of tuberculosis tend to contain necrosis (caseating tubercles), but non-necrotizing granulomas may also be present. Multinucleated giant cells with nuclei arranged like a horseshoe (Langhans giant cells) and foreign body giant cells are often present, but are not specific for tuberculosis. A definitive diagnosis of tuberculosis requires identification of the causative organism by microbiological cultures.
-
This question is part of the following fields:
- Microbiology
- Pathology
-
-
Question 149
Incorrect
-
The passage of leukocytes through the wall of the blood vessels is best described by which of the following terms?
Your Answer:
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.
-
This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
-
-
Question 150
Incorrect
-
A 76-year-old man with a urinary tract obstruction due to prostatic hyperplasia develops acute renal failure. Which of the following physiological abnormalities of acute renal failure will be most life threatening for this patient?
Your Answer:
Correct Answer: Acidosis
Explanation:Acute renal failure (ARF) is a rapid loss of renal function due to damage to the kidneys, resulting in retention of nitrogenous (urea and creatinine) and non-nitrogenous waste products that are normally excreted by the kidney. This accumulation may be accompanied by metabolic disturbances, such as metabolic acidosis and hyperkalaemia, changes in body fluid balance and effects on many other organ systems. Metabolic acidosis and hyperkalaemia are the two most serious biochemical manifestations of acute renal failure and may require medical treatment with sodium bicarbonate administration and antihyperkalaemic measures. If not appropriately treated these can be life-threatening. ARF is diagnosed on the basis of characteristic laboratory findings, such as elevated blood urea nitrogen and creatinine, or inability of the kidneys to produce sufficient amounts of urine.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 151
Incorrect
-
Routine evaluation of a 38 year old gentleman showed a slightly lower arterial oxygen [pa(O2)] than the alveolar oxygen [pA(O2)]. This difference is:
Your Answer:
Correct Answer: Is normal and due to shunted blood
Explanation:Blood that bypasses the ventilated parts of lung and enters the arterial circulation directly is known as shunted blood. It happens in normal people due to mixing of arterial blood with bronchial and some myocardial venous blood (which drains into the left heart). Diffusion limitation and reaction velocity with haemoglobin are immeasurably small. CO2 unloading will not affect the difference between alveolar and arterial p(O2). A large VSD will result in much lower arterial O2 as compared to alveolar O2.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 152
Incorrect
-
What is the normal amount of oxygen that is carried in the blood?
Your Answer:
Correct Answer: 20 ml oxygen/100 ml blood
Explanation:Normally, 100 ml of blood contains 15g haemoglobin and a single gram of haemoglobin can bind to 1.34 ml oxygen when 100% saturated. Thus, 15 × 1.34 = 20 ml O2/100 ml blood. The haemoglobin in venous blood that is leaving the tissues is about 75% saturated with oxygen, and hence it carries about 15 ml O2/100 ml venous blood. This implies that for each 10 ml of blood, 5 ml oxygen is transported to the tissues. With a p(O2) > 100 mm Hg, only 3 ml of oxygen is dissolved in every one litre of plasma. By increasing the pA(O2) by breathing 100% oxygen, one can add an extra amount of oxygen in the plasma, but the amount of oxygen carried by haemoglobin will not increase significantly as it is already > 95% saturated.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 153
Incorrect
-
Which of the following tumours is very radiosensitive?
Your Answer:
Correct Answer: Seminoma
Explanation:Seminoma is the most radiosensitive tumour and responds well to radiation therapy after unilateral orchidectomy. The ipsilateral inguinal areas are routinely not treated however, depending on the stage, the mediastinum and the left supraclavicular regions may also be irradiated.
-
This question is part of the following fields:
- Neoplasia; Urology
- Pathology
-
-
Question 154
Incorrect
-
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.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 155
Incorrect
-
A 60-year-old male is suspected to have pancreatic cancer. What particular tumour marker should be requested to aid in the confirmation of the diagnosis of pancreatic cancer?
Your Answer:
Correct Answer: Carcinoembryonic antigen (CEA)
Explanation:Carcinoembryonic antigen (CEA) is used as a tumour marker. CEA test measures the amount of this protein that may appear in the blood of some people who have certain types of cancers especially cancer of the colon and rectal cancer. It may also be present in the pancreas, breast, ovary or lung.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 156
Incorrect
-
Which of these antibiotics is the first choice treatment for infections caused by Pseudomonas aeruginosa?
Your Answer:
Correct Answer: Piperacillin
Explanation:Piperacillin is an extended-spectrum beta-lactam antibiotic of the ureidopenicillin class. It is normally used with a beta-lactamase inhibitor such as tazobactam. The combination has activity against many Gram-positive and Gram-negative pathogens and anaerobes, including Pseudomonas aeruginosa. Piperacillin is sometimes referred to as an anti-pseudomonal penicillin.
-
This question is part of the following fields:
- Pathology
- Pharmacology
-
-
Question 157
Incorrect
-
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.
-
This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
-
-
Question 158
Incorrect
-
A 30-year-old woman feels thirsty. This thirst is probably due to:
Your Answer:
Correct Answer: Increased level of angiotensin II
Explanation:Thirst is the basic need or instinct to drink. It arises from a lack of fluids and/or an increase in the concentration of certain osmolites such as salt. If the water volume of the body falls below a certain threshold or the osmolite concentration becomes too high, the brain signals thirst. Excessive thirst, known as polydipsia, along with excessive urination, known as polyuria, may be an indication of diabetes. Angiotensin II is a hormone that is a powerful dipsogen (i.e. it stimulates thirst) that acts via the subfornical organ. It increases secretion of ADH in the posterior pituitary and secretion of ACTH in the anterior pituitary.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 159
Incorrect
-
A 36-year-old woman suddenly suffers from a generalized seizure. She was previously healthy. An emergency CT scan reveals a mass in the posterior fossa, with distortion of the lateral ventricles. After removing the tumour, the biopsy reveals it contains glial fibrillary acidic protein (GEAP). What's the most likely diagnosis?
Your Answer:
Correct Answer: Astrocytoma
Explanation:Astrocytomas are primary intracranial tumours derived from astrocyte cells of the brain. They can arise in the cerebral hemispheres, in the posterior fossa, in the optic nerve and, rarely, in the spinal cord. These tumours express glial fibrillary acidic protein (GFAP). In almost half of cases, the first symptom of an astrocytoma is the onset of a focal or generalised seizure. Between 60% and 75% of patients will have recurrent seizures during the course of their illness. Secondary clinical sequelae may be caused by elevated intracranial pressure (ICP) cause by the direct mass effect, increased blood volume, or increased cerebrospinal fluid (CSF) volume. CT will usually show distortion of the third and lateral ventricles, with displacement of the anterior and middle cerebral arteries. Histological diagnosis with tissue biopsy will normally reveal an infiltrative character suggestive of the slow growing nature of the tumour.
-
This question is part of the following fields:
- Neurology
- Pathology
-
-
Question 160
Incorrect
-
Which tumour marker is associated with medullary carcinoma of thyroid?
Your Answer:
Correct Answer: Calcitonin
Explanation:Medullary carcinoma of thyroid accounts for 3% of thyroid cancers. It arises from the parafollicular cells (C cells) of the thyroid gland that produce calcitonin. It is often familial and caused by mutation of ret proto-oncogene, but can occasionally be sporadic. The familial cases can also occur as part of MEN syndromes IIA and IIB. The high calcitonin leads to down-regulation of the receptors, which does not affect the calcium levels significantly. Medullary carcinoma of thyroid shows characteristic amyloid deposits that stain positively with Congo red. The initial presentation consists of an asymptomatic thyroid nodule. Many cases are diagnosed due to routine screening of relatives of patients with MEN IIA and IIB. Medullary carcinoma can also cause ectopic production of other hormones/peptides such as adrenocorticotrophic hormone, vasoactive intestinal polypeptide, kallikreins and serotonin.
Metastasis from medullary carcinoma spread via the lymphatics to cervical and mediastinal nodes, and can also affect the liver, lungs and bone. Diagnosis is by raised serum calcitonin levels. A provocative test with calcium (15 mg/kg intravenously over 4 hours) also aids in diagnosis by leading to excessive secretion of calcitonin. X-ray might also show dense, conglomerate calcification.
CA-125 is frequently elevated in ovarian carcinomas. CA 15-3 is often associated with breast carcinomas. Alpha-fetoprotein is seen raised in hepatomas and gonadal tumours. Elevated HCG is associated with normal pregnancies, gonadal tumours, and choriocarcinomas. Thyroglobulin is used for surveillance in papillary carcinoma of thyroid. CA 19-9 is used in the management of pancreatic cancer.
-
This question is part of the following fields:
- Endocrine
- Pathology
-
-
Question 161
Incorrect
-
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:
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.
-
This question is part of the following fields:
- Orthopaedics
- Pathology
-
-
Question 162
Incorrect
-
If a catheter is placed in the main pulmonary artery of a healthy 30-year-old woman, which of the following will be its mean pulmonary arterial pressure?
Your Answer:
Correct Answer: 15 mmHg
Explanation:The pulmonary artery pressure (PA pressure) is a measure of the blood pressure found in the main pulmonary artery. The hydrostatic pressure of the pulmonary circulation refers to the actual pressure inside pulmonary vessels relative to atmospheric pressure. Hydrostatic (blood pressure) in the pulmonary vascular bed is low compared with that of similar systemic vessels. The mean pulmonary arterial pressure is about 15 mmHg (ranging from about 13 to 19 mmHg) and is much lower than the average systemic arterial pressure of 90 mmHg.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 163
Incorrect
-
A 65-year-old man complains of headaches, weakness, cramps, and confusion; blood tests reveal he has severe hyponatremia. The most likely cause is:
Your Answer:
Correct Answer: Severe diarrhoea or vomiting
Explanation:Hyponatraemia occurs when the sodium level in the plasma falls below 135 mmol/l. Hyponatraemia is an abnormality that can occur in isolation or, more commonly as a complication of other medical illnesses. Severe hyponatraemia may cause osmotic shift of water from the plasma into the brain cells. Typical symptoms include nausea, vomiting, headache and malaise. As the hyponatraemia worsens, confusion, diminished reflexes, convulsions, stupor or coma may occur. The cause of hyponatremia is typically classified by a person’s fluid status into low volume, normal volume, and high volume. Low volume hyponatremia can occur from diarrhoea, vomiting, diuretics, and sweating.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 164
Incorrect
-
Which of the following is the most accurate test for the diagnosis of primary syphilis?
Your Answer:
Correct Answer: Dark-field microscopy
Explanation:Primary syphilis is transmitted via sexual contact. Lesions on genitalia, called a chancre occur after an asymptomatic incubation period of 10-90 days (average 21 days) after exposure. This chancre is a typically solitary (can be multiple), firm, painless, ulceration over the skin at the point of exposure to spirochete, seen on penis, vagina or rectum. It heals spontaneously after 4-6 weeks. Local lymphadenopathy can be seen.
Diagnosis is made by microscopy of fluid from lesion using dark-field illumination, taking care to not confuse with other treponemal disease. Screening tests include rapid plasma regain (RPR) and Venereal Diseases Research Laboratory (VDRL) tests. False positives are known to occur with these tests and can be seen in viral infections like hepatitis, varicella, Epstein-Barr virus, tuberculosis, lymphoma, pregnancy and IV drug use. More specific tests should therefore be carried out in case these screening tests are positive.
The Treponema pallidum hemagglutination assay (TPHA) and the fluorescent treponemal antibody absorption (FTAABS) test are based on monoclonal antibodies and immunofluorescence and are more specific. However, they can too show false positives with other treponemal diseases like yaws or pinta. Other confirmatory tests include those based on enzyme-linked immunoassays.
-
This question is part of the following fields:
- Pathology
- Urology
-
-
Question 165
Incorrect
-
Which statement is correct regarding secretions from the adrenal glands?
Your Answer:
Correct Answer: Aldosterone is producd by the zona glomerulosa
Explanation:The secretions of the adrenal glands by zone are:
Zona glomerulosa – aldosterone
Zona fasciculata – cortisol and testosterone
Zona reticularis – oestradiol and progesterone
Adrenal medulia – adrenaline, noradrenaline and dopamine.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 166
Incorrect
-
A medical student is asked to calculate the net pressure difference in a capillary wall, considering: Interstitial fluid hydrostatic pressure = –3 mmHg, Plasma colloid osmotic pressure = 28 mmHg, Capillary hydrostatic pressure = 17 mmHg, Interstitial fluid colloid osmotic pressure = 8 mmHg, and Filtration coefficient = 1. Which is the correct answer?
Your Answer:
Correct Answer: 0 mmHg
Explanation:The rate of filtration at any point along a capillary depends on a balance of forces sometimes called Starling’s forces after the physiologist who first described their operation in detail. The Starling principle of fluid exchange is key to understanding how plasma fluid (solvent) within the bloodstream (intravascular fluid) moves to the space outside the bloodstream (extravascular space). Fluid movement = k[(pc– pi)–(Πc– Πi)] where k = capillary filtration coefficient, pc = capillary hydrostatic pressure, pi= interstitial hydrostatic pressure, Πc = capillary colloid osmotic pressure, Πi = interstitial colloid osmotic pressure. Therefore: 1 × [capillary hydrostatic pressure (17) – interstitial fluid hydrostatic pressure (–3)] – [plasma colloid osmotic pressure (28) – interstitial fluid colloid osmotic pressure (8)] = 0 mmHg
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 167
Incorrect
-
A 70-year-old man suffers an ischaemic stroke and develops a left homonymous hemianopia. Where is the likely infarct?
Your Answer:
Correct Answer: Right occipital lobe
Explanation:The man has a left homonymous hemianopia which means he is unable to view objects in the left visual field. This information is processed by the right primary visual cortex which lies in the right occipital lobe.
-
This question is part of the following fields:
- Neurology
- Pathology
-
-
Question 168
Incorrect
-
Which of the following is the most abundant WBC seen in a smear from a healthy person.
Your Answer:
Correct Answer: Neutrophils
Explanation:neutrophils are the most abundant cell type of the WBC. These phagocytes are found normally in the blood and increase in number are seen during an acute inflammation. These the percentages of WBC in blood Neutrophils: 40 to 60%
Lymphocytes: 20 to 40%
Monocytes: 2 to 8%
Eosinophils: 1 to 4%
Basophils: 0.5 to 1%
Band (young neutrophil): 0 to 3%. eosinophils, basophils, neutrophils are known as granulocytes and monocytes and lymphocytes as agranulocytes.
-
This question is part of the following fields:
- Inflammation & Immunology
- Pathology
-
-
Question 169
Incorrect
-
A 30-year-old man is brought to the emergency department suffering from extreme dehydration, and subsequent hypotension and tachycardia. Which part of the kidney will compensate for this loss?
Your Answer:
Correct Answer: Collecting ducts
Explanation:The collecting duct system of the kidney consists of a series of tubules and ducts that physically connect nephrons to a minor calyx or directly to the renal pelvis. The collecting duct system is the last component of the kidney to influence the body’s electrolyte and fluid balance. In humans, the system accounts for 4–5% of the kidney’s reabsorption of sodium and 5% of the kidney’s reabsorption of water. At times of extreme dehydration, over 24% of the filtered water may be reabsorbed in the collecting duct system.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 170
Incorrect
-
In a young, sexually active male, what is the most common cause of non-gonococcal urethritis?
Your Answer:
Correct Answer: Chlamydia
Explanation:Non-gonococcal urethritis is most commonly caused by Chlamydia trachomatis (50% cases). Less common organisms include Mycoplasma genitalium, Urea urealyticum and Trichomonas vaginalis. Chlamydia is also the commonest cause of non-gonococcal cervicitis in women and proctitis in both sexes.
-
This question is part of the following fields:
- Pathology
- Renal
-
-
Question 171
Incorrect
-
In which of the following conditions will the oxygen-haemoglobin dissociation curve shift to the right?
Your Answer:
Correct Answer: Exercise
Explanation:The oxygen-haemoglobin dissociation curve plots saturated haemoglobin against the oxygen tension and is usually a sigmoid plot. Each molecule of haemoglobin can bind to four molecules of oxygen reversibly. Factors that can influence the binding include: pH, concentration of 2,3-diphosphoglycerate (2,3-DPG), temperature, type of haemoglobin molecules, and presence of toxins, especially carbon monoxide. Shape of the curve is due to interaction of bound oxygen molecules with the incoming molecules. The binding of first molecule is difficult, with easier binding of the second and third molecule and increase in difficulty with the fourth molecule – partly as a result of crowding and partly as a natural tendency of oxygen to dissociate.
Left shift of curve indicates haemoglobin’s increased affinity for oxygen (seen at lungs). Right shift indicates decreased affinity and is seen with an increase in body temperature, hydrogen ions, 2,3-diphosphoglycerate (DPG), carbon dioxide concentration and exercise. Under normal resting conditions in a healthy individual, the normal position of the curve is at a pH of 7.4. A shift in the position of the curve with a change in pH is called the Bohr effect. Left shift occurs in acute alkalosis, decrease in p(CO2), decrease in temperature and decrease in 2,3-DPG. The fetal haemoglobin curve is to the left of the adult haemoglobin to allow for oxygen diffusion across the placenta. The curve for myoglobin is even further to the left. Carbon monoxide has a much higher affinity for haemoglobin than oxygen does. Thus, carbon monoxide poisoning leads to hypoxia.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 172
Incorrect
-
A patient is admitted to the ICU, and is prescribed tazobactam, amongst other drugs. What is the mechanism of action of tazobactam?
Your Answer:
Correct Answer: Inhibits beta-lactamase
Explanation:Tazobactam is a compound which inhibits the action of bacterial beta-lactamases. It is added to the extended-spectrum beta-lactam antibiotic piperacillin to broaden the spectrum of piperacillin by making it effective against organisms that express beta-lactamase and would normally degrade piperacillin.
-
This question is part of the following fields:
- Pathology
- Pharmacology
-
-
Question 173
Incorrect
-
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:
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.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 174
Incorrect
-
Renin is secreted by pericytes in the vicinity of the afferent arterioles of the kidney from the juxtaglomerular cells. Plasma renin levels are decreased in patients with:
Your Answer:
Correct Answer: Primary aldosteronism
Explanation:Primary aldosteronism, also known as primary hyperaldosteronism or Conn’s syndrome, is excess production of the hormone aldosterone by the adrenal glands resulting in low renin levels. Most patients with primary aldosteronism (Conn’s syndrome) have an adrenal adenoma. The increased plasma aldosterone concentration leads to increased renal Na+ reabsorption, which results in plasma volume expansion. The increase in plasma volume suppresses renin release from the juxtaglomerular apparatus and these patients usually have low plasma renin levels. Salt restriction and upright posture decrease renal perfusion pressure and therefore increases renin release from the juxtaglomerular apparatus. Secondary aldosteronism is due to elevated renin levels and may be caused by heart failure or renal artery stenosis.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 175
Incorrect
-
A 45-year-old-female is suspected to have a pulmonary mass. Supposing that she has a neoplasm, which of the following are most commonly found to involve the lung:
Your Answer:
Correct Answer: Pulmonary metastases
Explanation:Lung metastases occur when a cancer started in another part of the body (primary site) spreads to the lungs. The lungs are among the most common site where cancer can spread due to its rich systemic venous drainage, almost every type of cancer can spread to the lung. The most common types of cancer that spread to the lung are breast, colorectal, kidney, testicular, bladder, prostate, head and neck cancers.
-
This question is part of the following fields:
- Pathology
- Respiratory
-
-
Question 176
Incorrect
-
A 43-year-old diabetic man complains of headaches, palpitations, anxiety, abdominal pain and weakness. He is administered sodium bicarbonate used to treat:
Your Answer:
Correct Answer: Metabolic acidosis
Explanation:Sodium bicarbonate is indicated in the management of metabolic acidosis, which may occur in severe renal disease, uncontrolled diabetes, circulatory insufficiency due to shock or severe dehydration, extracorporeal circulation of blood, cardiac arrest and severe primary lactic acidosis. Bicarbonate is given at 50-100 mmol at a time under scrupulous monitoring of the arterial blood gas readings. This intervention, however, has some serious complications including lactic acidosis, and in those cases, should be used with great care.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 177
Incorrect
-
Which of the following is likely to result in hematocolpos in a 12-year old girl?
Your Answer:
Correct Answer: Imperforate hymen
Explanation:Hematocolpos means accumulation of blood in vagina and hematometra is accumulation of blood in the uterus. These are most likely seen with an imperforate hymen; which is seen I 1 in 2000 females. If spontaneous resolution does not occur, treatment involves making a hole in the hymen to allow discharge of menstrual blood.
-
This question is part of the following fields:
- Pathology
- Women's Health
-
-
Question 178
Incorrect
-
Dicloxacillin is an antibiotic; the subclass that dicloxacillin belongs to is:
Your Answer:
Correct Answer: Penicillin
Explanation:Dicloxacillin is a narrow-spectrum beta-lactam antibiotic. It is used to treat infections caused by susceptible Gram-positive bacteria and most effective against beta-lactamase-producing organisms such as Staphylococcus aureus. To decrease the development of resistance, dicloxacillin is recommended to treat infections that are suspected or proven to be caused by beta-lactamase-producing bacteria.
-
This question is part of the following fields:
- Pathology
- Pharmacology
-
-
Question 179
Incorrect
-
Which of these conditions is mithramycin used for?
Your Answer:
Correct Answer: Hypercalcaemia of malignancy
Explanation:Mithramycin or Plicamycin is a tricyclic pentaglycosidic antibiotic derived from Streptomyces strains. It inhibits RNA and protein synthesis by adhering to DNA. It is used as a fluorescent dye and as an antineoplastic agent. It is also used to reduce hypercalcaemia, especially caused by malignancy. Plicamycin is currently used in multiple areas of research, including cancer cell apoptosis and as a metastasis inhibitor.
-
This question is part of the following fields:
- Pathology
- Pharmacology
-
-
Question 180
Incorrect
-
A 45-year old lady underwent biopsy of a soft, fleshy mass involving her left breast. The biopsy showed lymphoid stroma with minimal fibrosis, surrounding sheets of large vesicular cells with frequent mitoses. Which condition is she most likely suffering from?
Your Answer:
Correct Answer: Medullary carcinoma of breast
Explanation:Medullary carcinoma is a malignant tumour of the breast with well-defined boundaries and accounts for 5% of all breast cancers. Other special features include a larger size of the neoplastic cells and presence of lymphoid cells at tumour edge. Differential diagnosis includes invasive ductal carcinoma. Prognosis is usually good.
-
This question is part of the following fields:
- Pathology
- Women's Health
-
-
Question 181
Incorrect
-
Abnormal breathing is noticed in a of victim of a road traffic accident, who sustained a head injury. The breathing pattern is characterised by alternate periods of waxing and waning tidal volumes with interspersed periods of apnoea. This breathing pattern is known as:
Your Answer:
Correct Answer: Cheyne–Stokes breathing
Explanation:Cheyne-Stokes breathing is an abnormal breathing pattern with breathing periods of gradually waxing and waning tidal volumes, with apnoeic periods interspersed. It is usually the first breathing pattern to be seen with a rise in intracranial pressure and is caused by failure of the respiratory centre in the brain to compensate quickly enough to changes in serum partial pressure of oxygen and carbon dioxide. The aetiology includes strokes, head injuries, brain tumours and congestive heart failure. It is also a sign of altitude sickness in normal people, a symptom of carbon monoxide poisoning or post-morphine administration. Biot’s respiration (cluster breathing) is characterized by cluster of quick, shallow inspirations followed by regular or irregular periods of apnoea. It is different from ataxic respiration, which has completely irregular breaths and pauses. It results due to damage to the medulla oblongata by any reason (stroke, uncal herniation, trauma) and is a poor prognostic indicator. Kussmaul breathing, also known as ‘air hunger’, is basically respiratory compensation for metabolic acidosis and is characterized by quick, deep and laboured breathing. It is most often seen in in diabetic ketoacidosis. Due to forced inspiratory rate, the patients will show a low p(CO2). Ondine’s curse is congenital central hypoventilation syndrome or primary alveolar hypoventilation, which can be fatal and leads to sleep apnoea. It involves an inborn failure to control breathing autonomically during sleep and in severe cases, can affect patients even while awake. It is known to occur in 1 in 200000 liveborn children. Treatment includes tracheostomies and life long mechanical ventilator support.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 182
Incorrect
-
What occurs during cellular atrophy?
Your Answer:
Correct Answer: Cell size decreases
Explanation:Atrophy is the decrease in the size of cells, tissues, or organs. There are several causes including inadequate nutrition, poor circulation, loss of hormonal support or nerve supply, disuse, lack of exercise, or disease. An increase in cell size is termed hypertrophy which is distinguished from hyperplasia, in which the cells remain approximately the same size but increase in number.
-
This question is part of the following fields:
- Cell Injury & Wound Healing; Urology
- Pathology
-
-
Question 183
Incorrect
-
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:
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.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
-
-
Question 184
Incorrect
-
A 7-year-old boy is diagnosed with metabolic acidosis as a result of severe dehydration. Which of the following conditions is most likely to cause severe dehydration and metabolic acidosis?
Your Answer:
Correct Answer: Severe diarrhoea
Explanation:Diarrhoea is defined as having three or more loose or liquid stools per day, or as having more stools than is normal for that person. Severe diarrhoea, causing fluid loss and loss of bicarbonate, will result in marked dehydration and metabolic acidosis.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 185
Incorrect
-
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:
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.
-
This question is part of the following fields:
- Endocrine
- Pathology
-
-
Question 186
Incorrect
-
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:
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.
-
This question is part of the following fields:
- Inflammation & Immunology; Respiratory
- Pathology
-
-
Question 187
Incorrect
-
Which of these structures is most likely to be damaged if a patient loses consciousness days or weeks after an otherwise insignificant head trauma, especially in elderly patients?
Your Answer:
Correct Answer: Dural bridging vein
Explanation:A subdural haematoma is a type of hematoma, usually associated with traumatic brain injury, in which blood collects between the dura mater and the pia-arachnoid mater. Symptoms of subdural haemorrhage have a slower onset than those of epidural haemorrhages because the lower pressure veins bleed more slowly than arteries. These injuries are more common in elderly patients, especially those taking antiplatelet or anticoagulant drugs. Oedema and increased intracranial pressure are unusual.
-
This question is part of the following fields:
- Neurology
- Pathology
-
-
Question 188
Incorrect
-
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:
Correct 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.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 189
Incorrect
-
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.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 190
Incorrect
-
A 30 year old man suffered severe blood loss, approx. 20-30% of his blood volume. What changes are most likely seen in the pulmonary vascular resistance (PVR) and pulmonary artery pressure (PAP) respectively following this decrease in cardiac output?
Your Answer:
Correct Answer: Increase Decrease
Explanation:Hypovolemia will result in the activation of the sympathetic adrenal discharge resulting is a decrease pulmonary artery pressure and an elevated pulmonary vascular resistance.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 191
Incorrect
-
Which of the following key features will be seen in an organ undergoing atrophy?
Your Answer:
Correct Answer: A greater number of autophagic vacuoles
Explanation:Atrophy is characterised by the breakdown of intracellular components along with organelles and packing them into vacuoles known as autophagic vacuoles. This is an adaptive response that separates the damaged cellular structures from the rest of the cells.
-
This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
-
-
Question 192
Incorrect
-
Which of the following malignancies is associated with the development of Lambert-Eaton myasthenic syndrome?
Your Answer:
Correct 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.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 193
Incorrect
-
Which of the following is NOT a Gram-negative rod?
Your Answer:
Correct Answer: Clostridium tetani
Explanation:Gram-positive rods include Clostridia, Listeria and diphtheroids.
Gram-negative rods include Escherichia coli, Klebsiella, Yersinia, Haemohilus, Pseudomonas, Shigella, Legionella, proteus and Salmonella
-
This question is part of the following fields:
- Microbiology
- Pathology
-
-
Question 194
Incorrect
-
A 55-year old lady underwent a major surgery for repair of an aortic aneurysm. Her blood pressure was low throughout the intra-operative and the post-operative period, along with increasing serum creatinine and urea. Microscopic examination of her urine showed multiple granular and hyaline casts. What is the likely condition the patient is suffering from?
Your Answer:
Correct Answer: Acute tubular necrosis
Explanation:The most common predisposing factor leading to acute tubular necrosis is ischemia, typically seen in hospitalized patients with low blood pressure.
-
This question is part of the following fields:
- Pathology
- Renal
-
-
Question 195
Incorrect
-
Which of the following is most likely to cause hypovolaemic hypernatremia:
Your Answer:
Correct Answer: Hyperalimentation
Explanation:Hypernatremia, characterised by a high serum sodium concentration, is rarely associated with volume overload (hypervolemia). A hypovolaemic hypernatremia may be seen during excessive administration of hypertonic sodium bicarbonate, hypertonic saline or hyperalimentation.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
-
-
Question 196
Incorrect
-
Which of the following has the least malignant potential?
Your Answer:
Correct 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).
-
This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
-
-
Question 197
Incorrect
-
A 27 year old women works in a dry-cleaning shop. She was exposed to massive amounts of carbon tetrachloride on her skin as well as inhaled. Which of the following organs is most susceptible to damage?
Your Answer:
Correct Answer: Liver
Explanation:Carbon tetrachloride (CCl4) is a common agent used in the dry cleaning industry and is thought to cause the formation of free radicals. It causes rapid breakdown of the endoplasmic reticulum due to decomposition of lipids and severe liver cell injury. Within less than 30 mins, hepatic protein synthesis declines, lipid export is reduced due to lack of apoprotein and there is an influx of calcium and cell death.
-
This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
-
-
Question 198
Incorrect
-
Hepatomegaly with greatly increased serum alpha-fetoprotein is seen in which of the following conditions?
Your Answer:
Correct Answer: Hepatocellular carcinoma
Explanation:Hepatocellular carcinoma or hepatoma affects people with pre-existing cirrhosis and is more common in areas with higher prevalence of hepatitis B and C. Diagnosis include raise alpha-fetoprotein levels, imaging and liver biopsy if needed. Patients at high-risk for developing this disease can undergo screening by periodic AFP measurement and abdominal ultrasonography. The malignancy carries poor prognosis (see also Answer to 10.4).
-
This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
-
-
Question 199
Incorrect
-
A 40 year old man suffered severe trauma following a MVA. His BP is 72/30 mmhg, heart rate of 142 beats/mins and very feeble pulse. He was transfused 3 units of blood and his BP returned to 100/70 and his heart rate slowed to 90 beats/min. What decreased after transfusion?
Your Answer:
Correct Answer: Total peripheral resistance
Explanation:The patient is in hypovolemic shock, he is transfused with blood, this fluid resuscitation will result in a decreased sympathetic discharge and adequate ventricular filling which will result in the decreases TPR with an increased CO and cardiac filling pressures
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 200
Incorrect
-
Paracentesis of ascetic fluid in a 45-year old woman revealed the following : clear, yellow fluid with protein 2.0 g/dl and a few mesothelial and mononuclear cells seen. No malignant cells seen. What is the likely diagnosis?
Your Answer:
Correct Answer: Cirrhosis
Explanation:Ascites develops either from:
-
- Increased accumulation
- Increased capillary permeability
- Increased venous pressure
- Decreased protein (oncotic pressure)
- Decreased clearance
- Increased lymphatic obstruction
- Increased accumulation
Cause
- Transudate (<30g/L protein) (Systemic disease)
- Liver (Cirrhosis)
- Cardiac e.g. RHF, CCF, SBE right heart valve disease and constrictive Pericarditis
- Renal failure
- Hypoalbuminaemia (nephrosis)
- Exudate (>30g/L protein) (Local disease)
- Malignancy
- Venous obstruction e.g. Budd-Chiari, Schistosomiasis
- Pancreatitis
- Lymphatic obstruction
- Infection (especially TB)
Cirrhosis is disease of the liver that is characterized by fibrosis leading to disorganization of the hepatic architecture. It shows the development of regenerative nodules surrounded by dense fibrotic tissue. Cirrhosis shows non-specific symptoms initially, which include fatigue, anorexia and weight loss. It can later progress to portal hypertension, ascites and liver failure.
-
-
This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
-
SESSION STATS - PERFORMANCE PER SPECIALTY
