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Question 1
Incorrect
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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: Renal artery stenosis
Correct 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 However, anti-hypertensives may affect the test results and should be withdrawn for 6 weeks.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.
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This question is part of the following fields:
- Endocrine
- Pathology
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Question 2
Incorrect
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What intrinsic muscle of the larynx is responsible for the tensing of the vocal cords?
Your Answer: Thyroarytenoid
Correct Answer: Cricothyroid muscle
Explanation:The cricothyroid muscle is the only tensor muscle of the larynx aiding with phonation. It attaches to the anterolateral aspect of the cricoid and the inferior cornu and lower lamina of the thyroid cartilage. Its action tilts the thyroid forward to help tense the vocal cords.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 3
Correct
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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: 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.
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This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
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Question 4
Incorrect
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A urologist makes a transverse suprapubic incision to retrieve a stone from the urinary bladder. Which of the following abdominal wall layers will the surgeon NOT traverse?
Your Answer: Transversalis fascia, extraperitoneal fat and peritoneum
Correct Answer: Posterior rectus sheath
Explanation:Pfannenstiel incision (a transverse suprapubic incision) is made below the arcuate line. Thus, there is no posterior layer of the rectus sheath here, only the transversalis fascia lines the inner layer of the rectus abdominis. The layers traversed include: skin, superficial fascia (fatty and membranous), deep fascia, anterior rectus sheath, rectus abdominis muscle, transversalis fascia, extraperitoneal connective tissue and peritoneum.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 5
Correct
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During a street fight a boy sustained a laceration below the elbow. It was a deep cut that led to profuse bleeding from an artery situated on the supinator muscle immediately below the elbow. The vessel most likely to have been injured is?
Your Answer: Radial recurrent artery
Explanation:The radial recurrent artery is situated on the supinator muscle then passing between the brachialis and the brachioradialis muscles. It originates from the radial artery and ends by anastomosing with the terminal part of the Profunda brachii.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 6
Incorrect
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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: Atrial flutter
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.
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This question is part of the following fields:
- Cardiovascular
- Pathology
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Question 7
Correct
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Arterial blood gas analysis of a man admitted with acute exacerbation of chronic obstructive pulmonary disease (COPD) showed the following: pH = 7.28, p(CO2) = 65.5 mmHg, p(O2)= 60 mmHg and standard bicarbonate = 30.5 mmol/l. This patient had:
Your Answer: Respiratory acidosis
Explanation:Acidosis with high p(CO2) and normal standard bicarbonate indicates respiratory acidosis, commonly seen in acute worsening of COPD patients. Respiratory acidosis occurs due to alveolar hypoventilation which leads to increased arterial carbon dioxide concentration (p(CO2)). This in turn decreases the HCO3 –/p(CO2) and decreases pH. In acute respiratory acidosis, the p(CO2) is raised above the upper limit of normal (over 45 mm Hg) with a low pH. However, in chronic cases, the raised p(CO2) is accompanied with a normal or near-normal pH due to renal compensation and an increased serum bicarbonate (HCO3 – > 30 mmHg).
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 8
Correct
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In the case of an injury to the sub sartorial canal, which of the following structures is most likely to be injured?
Your Answer: Nerve to vastus medialis
Explanation:The adductor canal (sub sartorial canal) is situated in the middle third of the thigh.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 9
Incorrect
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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: Lupus anticoagulant
Correct 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.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 10
Correct
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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: 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.
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This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
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Question 11
Incorrect
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A 36-year old gentleman with a history of cough for 4 weeks came to the hospital. Examination revealed multiple lymphadenopathy with splenomegaly. Investigations revealed haemoglobin 11 g/dl, haematocrit 32.4%, mean corpuscular volume (MCV) 93 fl, white blood cell count 63 × 109/l, and platelet count 39 × 109/l; along with characteristic Auer rods on peripheral blood smear. What is the likely diagnosis?
Your Answer: Hodgkin's lymphoma
Correct Answer: Acute myelogenous leukaemia (AML)
Explanation:AML, or acute myeloid leukaemia is the commonest acute leukaemia affecting adults. increasing in incidence with age. It is a malignancy of the myeloid line of white blood cells. It results in rapid proliferation of abnormal cells, which accumulate in the marrow. Interference with normal cell production leads to a drop in red blood cells, white blood cells and platelets. This causes symptoms such as tiredness, shortness of breath, tendency to bleed or bruise easily and recurrent infections. AML is known to progress quickly and can lead to death in weeks and months if not treated. Leukemic blasts of AML show presence of Auer rods. These are clumps of azurophilic granular material that form needles in the cytoplasm. Composed of fused lysosomes, these contain peroxidase, lysosomal enzymes and crystalline inclusions. Auer rods are classically present in myeloid blasts of M1, M2, M3 and M4 acute leukaemia. They also help to distinguish the preleukemia myelodysplastic syndromes.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 12
Correct
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The following organs would be expected to lie within the right lower quadrant of the abdomen, assuming that the gastrointestinal tract is rotated normally:
Your Answer: Distal jejunum, caecum, vermiform appendix
Explanation:The abdomen is divided by theoretical anatomic lines into four quadrants. The median plane follows the linea alba and extends from the xiphoid process to the pubic symphysis and splits the abdomen in half. The transumbilical plane is a horizontal line that runs at the level of the umbilicus. This forms the upper right and left quadrants and the lower right and left quadrants. Structures in the right lower quadrant include: caecum, appendix, part of the small intestine, ascending colon, the right half of the female reproductive system, right ureter. Pain in this region is most commonly associated with appendicitis.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 13
Correct
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The pterion is clinically significant as it marks an area of weakness on the skull. What structure lies beneath it?
Your Answer: Anterior branches of the middle meningeal artery
Explanation:The pterion is the area where four bones, the parietal, frontal, greater wing of sphenoid and the squamous part of the temporal bone meet. It overlies the anterior branch of the middle meningeal artery on the internal aspect of the skull. The pterion is the weakest part of the skull. Slight trauma to this region can cause extradural hematoma.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 14
Correct
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The gynaecologist suspects that her patient has a cervical cancer. What particular test should be done on this patient to screen for cervical cancer?
Your Answer: Pap smear
Explanation:Worldwide, approximately 500,000 new cases of cervical cancer and 274,000 deaths are attributable to cervical cancer yearly. This makes cervical cancer the second most common cause of death from cancer in women. The mainstay of cervical cancer screening has been the Papanicolaou test (Pap smear).
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 15
Correct
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The superior ulnar collateral artery is a direct branch of this artery:
Your Answer: Brachial
Explanation:The brachial artery gives rise to a small branch at the middle of the arm, which is the superior collateral artery. It descends accompanied by the ulnar nerve and anastomoses with the posterior ulnar recurrent and inferior ulnar collateral.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 16
Incorrect
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A CT-scan of the lung shows a tumour crossing the minor (horizontal) fissure. This fissure separates:
Your Answer: The lower lobe from the middle lobe
Correct Answer: The middle lobe from the upper lobe
Explanation:The horizontal fissure separates the upper lobe from the middle lobe. The oblique fissure on the other hand separates the lower lobe from both the middle and upper lobes. The lingula is found only on the left lung.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 17
Correct
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Endometrial hyperplasia is most likely to be associated with which of the following conditions?
Your Answer: Fibrothecoma
Explanation:A benign tumour arising from the ovarian stroma, fibrothecoma are bilateral in 10% cases. The thecoma component of the tumour can produce oestrogen leading to endometrial hyperplasia. The thecoma is rich in lipid content and is responsible for the yellowish appearance of the tumour. Meig’s syndrome is the presence of fibrothecoma with a right-sided hydrothorax.
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This question is part of the following fields:
- Pathology
- Women's Health
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Question 18
Incorrect
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A patient is admitted to the ICU, and is prescribed tazobactam, amongst other drugs. What is the mechanism of action of tazobactam?
Your Answer: Inhibits CD3 receptor
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.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 19
Correct
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A patient at the time of her second delivery opted for a bilateral pudendal nerve block. In order to inject the anaesthetic agent near the pudendal nerve a anaesthetic consultant had to insert a finger into the vagina and press laterally to palpate which landmark?
Your Answer: Ischial spine
Explanation:The ischial spine is always palpated through the walls of the vagina when performing a transvaginal pudendal nerve block and can easily be palpated on the lateral wall of the vagina.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 20
Correct
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During an OSCE exam a medical student is asked to locate the sternal angle. The sternal angle is a land mark for locating the level of the:
Your Answer: Second costal cartilage
Explanation:The sternal angle, a key landmark used in the clinic for auscultating for heart sounds, is the point of attachment of the costal cartilage of rib 2 to the sternum. It thus corresponds to the location of the second rib. A horizontal plane through the sternal angle traverses the T4/T5 intervertebral disc and marks the inferior boundary of the superior mediastinum.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 21
Correct
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Which of the following is true about myasthenia gravis?
Your Answer: Response of skeletal muscle to nerve stimulation is weakened
Explanation:An autoimmune disorder, myasthenia gravis leads to progressive muscle weakness. It occurs due to formation of antibodies against the nicotinic acetylcholine (ACh) receptor of the motor endplate, which leads to impaired neuromuscular transmission. Thus, nerve stimulation will lead to a weakened muscle response, but direct electrical stimulation will bring about a normal response. Diagnostic test includes improvement of muscle weakness by small doses of acetylcholinesterase inhibitors (physostigmine or edrophonium). However, a large dose of physostigmine worsens the weakness due to desensitisation of the endplate to persistent Ach. One of the investigative tools includes radiolabelled snake venom α-bungarotoxin. It is an in vitro study performed on muscle biopsy specimens and used to quantify the number of ACh receptors at the motor endplate.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 22
Correct
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Which antibiotic acts by inhibiting protein synthesis?
Your Answer: Erythromycin
Explanation:Penicillins and cephalosporins (e.g. cefuroxime, cefotaxime, ceftriaxone) inhibit bacterial cell wall synthesis through the inhibition of peptidoglycan cross-linking.
Macrolides (e.g. erythromycin), tetracyclines, aminoglycosides and chloramphenicol act by interfering with bacterial protein synthesis.
Sulphonamides (e.g. trimethoprim, co-trimoxazole) work by inhibiting the synthesis of nucleic acid
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This question is part of the following fields:
- Pharmacology; Microbiology
- Physiology
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Question 23
Correct
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The histological exam of a tuberculous granuloma shows a periphery of multinuclear giant cells, with a central area of:
Your Answer: Caseous necrosis
Explanation:Granulomas with necrosis tend to have an infectious cause. The chronic infective lesion in this case typically presents with a central area of caseous (cheese-like) necrosis. Foam cells are the fat-laden M2 macrophages seen in atherosclerosis
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This question is part of the following fields:
- Cell Injury & Wound Healing; Dermatology
- Pathology
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Question 24
Correct
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A 45 year old man who complains of chronic post prandial, burning epigastric pain undergoes a gastrointestinal endoscopy. There is no apparent mass or haemorrhage and a biopsy is taken from the lower oesophageal mucosa just above the gastro-oesophageal junction. The results reveal the presence of columnar cells interspersed with goblet cells. Which change best explains the above mentioned histology?
Your Answer: Metaplasia
Explanation:Metaplasia is the transformation of one type of epithelium into another as a means to better cope with external stress on that epithelium. In this case metaplasia occurs due to the inflammation resulting from gastro-oesophageal reflux disease. Dysplasia is disordered cellular growth. Hyperplasia is an increase in cell number but not cell type i.e. transformation. Carcinoma is characterized by cellular atypia. Ischaemia would result in necrosis with ulceration. Carcinoma insitu involves dysplastic atypical cells with the basement membrane intact and atrophy would mean a decrease in number of cells.
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This question is part of the following fields:
- Cell Injury & Wound Healing; Gastrointestinal
- Pathology
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Question 25
Incorrect
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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: Pseudomonas aeruginosa
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.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 26
Correct
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A 20-year old boy presented with low grade fever, night sweats and weakness over two months. On examination, he had multiple, non-tender, cervical, supraclavicular and axillary adenopathy. Microscopy of lymph node biopsy showed the presence of Reed-Sternberg cells. He is likely suffering from:
Your Answer: Hodgkin’s lymphoma
Explanation:Hodgkin’s lymphoma is a disease characterized by malignant proliferation of cells of the lymphoreticular system. It can be localized or disseminated, and can involve the nodes, spleen, liver and marrow. Symptoms of the disease include non-tender lymphadenopathy, fever, night sweats, weight loss, itching and hepatosplenomegaly. Histologically, the involved nodes show the presence of Reed-Sternberg cells, which are large, binucleated cells, in a heterogenous cellular infiltrate of histiocytes, lymphocytes, monocytes, plasma cells and eosinophils.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 27
Correct
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A 25 year-old female medical student presents with fever, lack of appetite, rashes, sore throat and lymphadenopathy. Peripheral smear shows atypical lymphocytes. Which is the most likely organism responsible for this patient's condition?
Your Answer: Epstein–Barr virus
Explanation:Epstein-Barr virus is in the herpes family of viruses and most people will become infected with EBV sometime during their lives. EBV commonly causes infectious mononucleosis, or mono, a contagious viral illness that initially attacks the lymph nodes in the neck and throat. When these tissues become less effective in fighting infection, sore throats, swelling of the nodes and fever may result.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 28
Correct
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A patient is suspected to have Blastomyces dermatidis infection. The patient contracted the disease most likely through which port of entry?
Your Answer: Respiratory tract
Explanation:Blastomycosis disease is a fungal infection acquired through inhalation of the spores. It caused by the organism Blastomyces dermatitidis and manifests as a primary lung infection in about 70% of cases. The onset is relatively slow and symptoms are suggestive of pneumonia.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 29
Correct
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The posterior cord contains nerve fibres from which of the following levels of the spinal cord?
Your Answer: C5, C6, C7, C8 and T1
Explanation:THE correct answer is A. The posterior cord derives its fibres from the spinal nerves C5,C6,C7,C8,T1. This cord is formed from the fusion of the posterior divisions of the upper, lower, and middle trunks.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 30
Incorrect
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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: Prolactinoma
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.
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This question is part of the following fields:
- Endocrine
- Pathology
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Question 31
Correct
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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: 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.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 32
Incorrect
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An excised lesion is found to be a premalignant during examination by the pathologist. What is the most likely histopathology report of this lesion?
Your Answer: Familial polyposis
Correct Answer: Solar keratosis
Explanation:Premalignant condition is a state of disordered morphology of cells that is associated with an increased risk of cancer. If this condition is left untreated, it may lead to the development of cancer. The following are examples of pre-malignant lesions: actinic keratosis, Barret’s oesophagitis, atrophic gastritis, ductal carcinoma in situ, dyskeratosis congenita, sideropenic dysphagia, lichen planus, oral submucous fibrosis, solar elastosis, cervical dysplasia, leucoplakia and erythroplakia.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 33
Correct
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A child defecates a few minutes after being fed by the mother. This is most likely due to:
Your Answer: Gastrocolic reflex
Explanation:The gastrocolic reflex is a physiological reflex that involves increase in colonic motility in response to stretch in the stomach and by-products of digestion in the small intestine. It is shown to be uneven in its distribution throughout the colon, with the sigmoid colon affected more than the right side of the colon in terms of a phasic response. Various neuropeptides have been proposed as mediators of this reflex, such as serotonin, neurotensin, cholecystokinin and gastrin.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 34
Correct
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The primary area involved in the pathology of Parkinson's disease is:
Your Answer: Substantia nigra
Explanation:Parkinson’s disease is a degenerative, movement disorder of the central nervous system, and is typically characterized by muscle rigidity, tremor and bradykinesia (in extreme cases, akinesia). Secondary symptoms include high-level cognitive dysfunction and subtle language problems.
Parkinson’s disease is also called ‘primary Parkinsonism’ or ‘idiopathic Parkinson’s disease and is the most common cause of Parkinsonism, a group of similar symptoms. The disorder is caused due to loss of pigmented dopaminergic cells in the pars compacta region of the substantia nigra.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 35
Incorrect
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Which of these conditions is mithramycin used for?
Your Answer: Organ transplantation
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.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 36
Incorrect
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An organ transplant patient may be at risk of developing which type of cancer?
Your Answer: Lung cancer
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.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 37
Correct
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Which of the following is likely to result in hematocolpos in a 12-year old girl?
Your 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.
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This question is part of the following fields:
- Pathology
- Women's Health
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Question 38
Correct
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The following branch of the aorta is unpaired:
Your Answer: Coeliac artery
Explanation:Branches that stem from the abdominal aorta can be divided into three: the visceral branches, parietal branches and terminal branches. Of the visceral branches, the suprarenal, renal, testicular and ovarian arteries are paired while the coeliac artery and superior and inferior mesenteric arteries are unpaired. Of the parietal branches the inferior phrenic and lumbar arteries are paired while the middle sacral artery is unpaired. The terminal branches i.e. the common iliac arteries are paired.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 39
Correct
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The vascular structure found on the right side of the fifth lumbar vertebra is?
Your Answer: Inferior vena cava
Explanation:The most likely vascular structure is the inferior vena cava. The inferior vena cava is formed by the joining of the two common iliac arteries, the right and the left iliac artery, at the level of the fifth lumbar vertebra( L5). The inferior vena cava passes along the right side of the vertebral column. It enters the thoracic cavity into the underside of the heart through the caval opening of the diaphragm at the level of the eight thoracic vertebra (T8).
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 40
Incorrect
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Which cells are most commonly seen in a granulomatous lesion that suggests an underlying chronic inflammation?
Your Answer: Mast cells
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.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 41
Correct
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During an exploratory laparotomy of an acute abdomen, the surgeon identified an inflamed Meckel's diverticulum. This is:
Your Answer: Is a site of ectopic pancreatic tissue
Explanation:Meckel’s diverticulum is an outpouching of the small intestine. It usually occurs about 0.6 m (2 feet) before the junction with the caecum. It can be lined with the mucosa of the stomach and may ulcerate. It may also be lined by ectopic pancreatic tissue. It represents the remains of the vitelline duct in early fetal life.
An abnormal persistence of the urachus is called a urachal fistula.
Failure of the midgut loop to return to the abdominal cavity is called an omphalocele.
Polyhydramnios is often caused by anencephaly or oesophageal fistula.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 42
Incorrect
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During routine laboratory tests, a 66-year-old man is found to be suffering from hypercholesterolaemia and is prescribed atorvastatin. What is the mechanism of action of atorvastatin?
Your Answer: Decreases cholesterol absorption in the small intestine
Correct Answer: Inhibits cholesterol synthesis
Explanation:Atorvastatin is a member of the drug class of statins, used for lowering cholesterol. The mode of action of statins is inhibition of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase. This enzyme is needed by the body to make cholesterol. The primary uses of atorvastatin is for the treatment of dyslipidaemia and the prevention of cardiovascular disease.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 43
Correct
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Action potentials are used extensively by the nervous system to communicate between neurones and muscles or glands. What happens during the activation of a nerve cell membrane?
Your Answer: Sodium ions flow inward
Explanation:During the generation of an action potential, the membrane gets depolarized which cause the voltage gated sodium channels to open and sodium diffuses inside the neuron, resulting in the membrane potential moving towards a positive value. This positive potential will then open the voltage gated potassium channels and cause more K+ to move out decreasing the membrane potential and restoring the membrane potential to its resting value.
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This question is part of the following fields:
- General
- Physiology
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Question 44
Correct
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A patient admitted for esophagectomy showed low levels of the lightest plasma protein in terms of weight. Which of the following is the lightest plasma protein:
Your Answer: Albumin
Explanation:Albumin is the most abundant and the lightest of all the plasma proteins. It maintains osmotic pressure, transports unconjugated bilirubin, thyroid hormones, fatty acids, drugs and acts as a buffer for pH.
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This question is part of the following fields:
- General
- Physiology
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Question 45
Correct
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Question 46
Incorrect
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Loperamide is a drug used to treat diarrhoea. What is the mechanism of action of loperamide?
Your Answer: Inactivates pepsin
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.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 47
Correct
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The thyroid gland is a large ductless gland located in which part of the neck?
Your Answer: Visceral space
Explanation:The thyroid gland is an endocrine gland in the neck, consisting of two lobes connected by an isthmus. It is situated at the front and sides of the neck in the visceral space.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 48
Correct
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A 60-year old man with a left-sided indirect inguinal hernia underwent emergency surgery to relieve large bowel obstruction resulting from a segment of the bowel being strangulated in the hernial sac. The most likely intestinal segment involved is:
Your Answer: Sigmoid colon
Explanation:The sigmoid colon is the most likely segment involved as it is mobile due to the presence of the sigmoid mesocolon. The descending colon, although on the left side, is a bit superior and is also retroperitoneal. The ascending colon and caecum are on the right side of the abdomen. The rectum is too inferior to enter the deep inguinal ring and the transverse colon is too superior to be involved.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 49
Incorrect
-
A lesion involving the suprachiasmatic nucleus of hypothalamus is likely to affect:
Your Answer: Temperature regulation
Correct Answer: Regulation of circadian rhythm
Explanation:The suprachiasmatic nucleus (SCN) in the hypothalamus is responsible for controlling endogenous circadian rhythms and destruction of the SCN leads to a loss of circadian rhythm.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 50
Incorrect
-
A Jewish man was diagnosed with haemophilia C. Which of the following factors is deficient in this form of haemophilia?
Your Answer: Factor VII
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.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 51
Correct
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A 25-year-old female had a painful abdomen and several episodes of vomiting. She was severely dehydrated when she was brought to the hospital. Her ABG showed a pH 7.7, p(O2) 75 mmHg, p(CO2) 46 mmHg and bicarbonate 48 mmol/l. The most likely interpretation of this ABG report would be:
Your Answer: Metabolic alkalosis
Explanation:Metabolic alkalosis is a primary increase in bicarbonate (HCO3−) with or without compensatory increase in carbon dioxide partial pressure (Pco2); pH may be high or nearly normal. Metabolic alkalosis occurs as a consequence of a loss of H+ from the body or a gain in HCO3 -. In its pure form, it manifests as alkalemia (pH >7.40). As a compensatory mechanism, metabolic alkalosis leads to alveolar hypoventilation with a rise in arterial carbon dioxide tension p(CO2), which diminishes the change in pH that would otherwise occur. Normally, arterial p(CO2) increases by 0.5–0.7 mmHg for every 1 mmol/l increase in plasma bicarbonate concentration, a compensatory response that occurs very rapidly. If the change in p(CO2) is not within this range, then a mixed acid–base disturbance occurs. Likewise, if the increase in p(CO2) is less than the expected change, then a primary respiratory alkalosis is also present. However an elevated serum bicarbonate concentration can also occur due to a compensatory response to primary respiratory acidosis. A bicarbonate concentration greater than 35 mmol/l is almost always caused by metabolic alkalosis (as is the case in this clinical scenario). Calculation of the serum anion gap can also help to differentiate between primary metabolic alkalosis and the metabolic compensation for respiratory acidosis. The anion gap is frequently elevated to a modest degree in metabolic alkalosis because of the increase in the negative charge of albumin and the enhanced production of lactate. However, the only definitive way to diagnose metabolic alkalosis is by performing a simultaneous blood gases analysis, which reveals elevation of both pH and arterial p(CO2) and increased calculated bicarbonate.
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This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
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Question 52
Correct
-
Which statement is correct regarding coagulation?
Your Answer: Thrombin converts fibrinogen to fibrin
Explanation:Coagulation of blood is a complex process and an important part of haemostasis. There are two main pathways related to coagulation: the contact activation pathway/intrinsic pathway and tissue factor/extrinsic pathway. The extrinsic pathway is activated by external trauma that causes blood to escape from the vascular system. This pathway is quicker than the intrinsic pathway and involves factor VII. The intrinsic pathway is activated by trauma inside the vascular system, and initiated by platelets, exposed endothelium, chemicals, or collagen. This pathway is slower than the extrinsic pathway, but more important. It involves factors XII, XI, IX, VIII. Both pathways meet to finish the formation of a clot in what is known as the common pathway. The common pathway involves factors I, II, V, and X. They converge on the common pathway in which activation of prothrombin to thrombin leads to conversion of fibrinogen to fibrin and clot formation.
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This question is part of the following fields:
- General
- Physiology
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Question 53
Incorrect
-
If a patient takes long-term corticosteroid therapy, which of the following diseases is most likely to develop?
Your Answer: Rickets
Correct Answer: Osteoporosis
Explanation:One of the complications of long-term intake of corticosteroids is osteoporosis. Some guidelines recommend prophylactic calcium and vitamin D supplementation in patients who take more than 30 mg hydrocortisone or 7.5 mg of prednisolone daily.
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This question is part of the following fields:
- Orthopaedics
- Pathology
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Question 54
Correct
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The optic foramen, superior orbital fissure, foramen ovale, foramen rotundum and foramen sinosum are all located on which bone at the base of the skull?
Your Answer: Sphenoid
Explanation:The sphenoid bone consists of two parts, a central part and two wing-like structures that extend sideways towards each side of the skull. It forms the base of the skull, and floor and sides of the orbit. On its central part lies the optic foramen. The foramen ovale, foramen spinosum and foramen rotundum lie on its great wing while the superior orbital fissure lies on its lesser wing.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 55
Correct
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Which is the correct statement regarding gonadal venous drainage:
Your Answer: The left ovarian vein drains into the left renal vein
Explanation:Spermatic or testicular veins arise from the posterior aspect of the testis and receive tributaries from the epididymis. Upon uniting, they form the pampiniform plexus that makes up the greater mass of the spermatic cord. The vessels that make up this plexus rise up the spermatic cord in front of the ductus deferens. They then unite, below the superficial ring, to form three or four veins that traverse the inguinal canal and enter the abdomen through the deep inguinal ring. They further unite to form 2 veins that ascend up the psoas major muscle behind the peritoneum each lying on either side of the testicular artery. These further unite to form one vein that empties on the right side of the inferior vena cava at an acute angle and on the left side into the renal vein, at a right angle. The left testicular vein courses behind the iliac colon and is thus exposed to pressure from the contents of this part of the bowel. The ovarian vein is the equivalent of the testicular vein in women. They form a plexus in the broad ligament near the ovary and uterine tube and communicate with the uterine plexus. They drain into similar vessels as in a man.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 56
Incorrect
-
A 45-year old gentleman presents with diarrhoea for two weeks. He has no history of fever and the diarrhoea stops on fasting. Which is the most likely type of diarrhoea that he is suffering from?
Your Answer: Secretory
Correct Answer: Osmotic
Explanation:The different types of diarrhoea are:
1. Secretory diarrhoea – Due to increased secretion or decreased absorption. There is minimal to no structural damage in this type. The most common cause is cholera toxin which stimulates secretion of anions (especially chloride), with sodium and water.
2. Osmotic diarrhoea – Due to increased osmotic load, there is water loss. This occurs in cases of maldigestion syndromes, such as coeliac or pancreatic disease.
3. Motility-related diarrhoea – Occurs in cases of abnormal gastrointestinal motility. Due to increased motility, there is poor absorption and this leads to diarrhoea. This is seen post-vagotomy or in diabetic neuropathy.
4. Inflammatory diarrhoea – Due to damage to the mucosa or brush border, there is a loss of protein-rich fluids and poor absorption. Features of all the above three types can be seen in this type. Aetiology includes bacterial, viral, parasitic infections or autoimmune problems including inflammatory bowel disease.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 57
Correct
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Myoglobin is released as a result of rhabdomyolysis from damaged skeletal muscles. What function do they perform in the muscle?
Your Answer: Acts like haemoglobin and binds with O2
Explanation:Myoglobin is a pigmented globular protein made up of 153 amino acids with a prosthetic group containing haem around which the apoprotein folds. It is the primary oxygen carrying protein of the muscles. The binding of oxygen to myoglobin is unaffected by the oxygen pressure as it has an instant tendency to bind given its hyperbolic oxygen curve. It releases oxygen at very low pO2 levels.
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This question is part of the following fields:
- General
- Physiology
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Question 58
Correct
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Most of the coagulation factors are serine proteases. Which of the following is not one of them?
Your Answer: Factor XIII
Explanation:Serine protease coagulation factors include: thrombin, plasmin, Factors X, XI and XII. Factor VIII and factor V are glycoproteins and factor XIII is a transglutaminase.
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This question is part of the following fields:
- General
- Physiology
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Question 59
Correct
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A syndrome responsible for failure to absorb vitamin B12 from the GIT is called?
Your Answer: Pernicious anaemia
Explanation:Pernicious anaemia is a type of autoimmune disease in which antibodies form against the parietal cells or intrinsic factor. Intrinsic factor is required for the absorption of vitamin B12. Blood testing typically shows a macrocytic, normochromic anaemia and low levels of serum vitamin B12. A Schilling test can then be used to distinguish between pernicious anaemia, vitamin B12 malabsorption and vitamin B12 deficiency. Symptoms include shortness of breath, pallor and diarrhoea etc.
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This question is part of the following fields:
- General
- Physiology
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Question 60
Incorrect
-
Which of the following arteries branch from the deep femoral artery and course between the pectineus and iliopsoas muscles?
Your Answer: Lateral ascending femoral circumflex
Correct Answer: Medial femoral circumflex
Explanation:The medial femoral circumflex artery is an artery in the upper thigh that supplies blood to the head and neck of the femur. It arises from the deep femoral artery and winds around the medial side of the femur. It passes first between pectineus and psoas major, and then between obturator externus and adductor brevis.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 61
Incorrect
-
The tympanic membrane is a thin semi-transparent membrane that separates the tympanic cavity from the bottom of the external acoustic meatus. The interior of the tympanic membrane is innervated by which of the following cranial nerves?
Your Answer: Vestibulocochlear
Correct Answer: Glossopharyngeal
Explanation:The glossopharyngeal nerve, known as the ninth cranial nerve (CN IX), is a mixed nerve that carries afferent sensory and efferent motor information. The glossopharyngeal nerve has five distinct general functions:
– The branchial motor (special visceral efferent), supplies the stylopharyngeus muscle.
– The visceral motor (general visceral efferent), provides parasympathetic innervation of the parotid gland via the otic ganglion.
– The visceral sensory (general visceral afferent), carries visceral sensory information from the carotid sinus and carotid body.
– The general sensory (general somatic afferent), provides general sensory information from the inner surface of the tympanic membrane, upper pharynx (GVA), and the posterior one-third of the tongue.
– The visceral afferent (special visceral afferent), provides taste sensation from the posterior one-third of the tongue, including the circumvallate papillae.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 62
Incorrect
-
After a total colectomy and ileotomy, a 50-year old diabetic man who was a known case of diabetic nephropathy had persistent metabolic acidosis. The patient appeared well perfused, with normal vital signs and normal fluid balance. Investigations revealed:
Sodium = 132 mmol/l
Potassium = 6.6 mmol/l
Creatinine = 185 μmol/l (2.16 mg/dl)
Chloride = 109 μmol/l
8am cortisol = 500 nmol/l (18 μg/dl)
pH = 7.29, p(CO2) = 27 mmHg
p(O2) = 107 mmHg
standard bicarbonate = 12 mmol/l.
What is the likely causes of his acidosis?Your Answer: Ketoacidosis
Correct Answer: Renal tubular acidosis
Explanation:Acidosis here is due to low bicarbonate. The low p(CO2) is seen in compensation. The anion gap is normal, ruling out intra-abdominal ischaemia (which leads to metabolic acidosis). If it was a gastrointestinal aetiology, low potassium would be seen. The history of diabetic nephropathy predisposes to renal tubular acidosis. Type 4 (hyporeninaemic hypoaldosteronism) is associated with high potassium and is found in diabetic and hypertensive renal disease.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 63
Incorrect
-
Which statement is true regarding the diaphragmatic openings:
Your Answer: The aorta passes through the opening at T10
Correct Answer: The thoracic duct passes through the opening at T12
Explanation:The diaphragmatic openings are:
T8 – opening for the inferior vena cavaand the right phrenic nerve
T10 – opening for the oesophagusand the left gastric artery and vein
T12 – opening for the aorta, the thoracic duct and azygos vein.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 64
Correct
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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: 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.
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This question is part of the following fields:
- Cardiovascular
- Pathology
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Question 65
Correct
-
Digital rectal examination of a 75-year old gentleman who presented to the surgical clinic with urinary retention revealed an enlarged, nodular prostate. PSA was found to be elevated, favouring the diagnosis of prostatic malignancy. Which of the given options is the most common malignant lesion affecting the prostate gland?
Your Answer: Adenocarcinoma
Explanation:Prostatic adenocarcinoma is the commonest solid malignancy and non-dermatological cancer in men above 50 years age. Increasing in incidence with age and the highest risk seen in the black population. About 75% of cases are seen in men over 65 years. Other tumours affecting the prostate include undifferentiated prostate cancer, squamous cell carcinoma, and ductal transitional carcinoma, but these occur less commonly. Sarcomas usually affect children. Hormones play a role in the aetiology of prostate adenocarcinoma unlike the other types. Intraepithelial neoplasia is considered a precursor of invasive malignancy.
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This question is part of the following fields:
- Pathology
- Urology
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Question 66
Correct
-
Which of the following toxins most likely results in continuous cAMP production, which pumps H2O, sodium, potassium, chloride and bicarbonate into the lumen of the small intestine and results in rapid dehydration?
Your Answer: Cholera toxin
Explanation:The cholera toxin (CTX or CT) is an oligomeric complex made up of six protein subunits: a single copy of the A subunit (part A), and five copies of the B subunit (part B), connected by a disulphide bond. The five B subunits form a five-membered ring that binds to GM1 gangliosides on the surface of the intestinal epithelium cells. The A1 portion of the A subunit is an enzyme that ADP-ribosylates G proteins, while the A2 chain fits into the central pore of the B subunit ring. Upon binding, the complex is taken into the cell via receptor-mediated endocytosis. Once inside the cell, the disulphide bond is reduced, and the A1 subunit is freed to bind with a human partner protein called ADP-ribosylation factor 6 (Arf6). Binding exposes its active site, allowing it to permanently ribosylate the Gs alpha subunit of the heterotrimeric G protein. This results in constitutive cAMP production, which in turn leads to secretion of H2O, Na+, K+, Cl−, and HCO3− into the lumen of the small intestine and rapid dehydration. The gene encoding the cholera toxin was introduced into V. cholerae by horizontal gene transfer.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 67
Incorrect
-
An old man presented with atrophy of the thenar eminence despite the sensation over it still being intact. What is the injured nerve in this case?
Your Answer: Ulnar nerve
Correct Answer: Median nerve
Explanation:Atrophy of the thenar muscles means injury to the motor supply of these muscles. The nerve that sends innervation to it is the median nerve. But the median nerve does not provide sensory innervation to the overlying skin so sensation is spared.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 68
Correct
-
A 35-year old lady presents to her GP with vague abdominal symptoms. Examination reveals a normal size spleen. Which of the following is the likely diagnosis?
Your Answer: Idiopathic thrombocytopenic purpura
Explanation:Idiopathic thrombocytopenic purpura (ITP) is a disease caused due to development of an antibody against a platelet antigen (autoantibody). In childhood disease, the autoantibody gets triggered by binding of viral antigen to the megakaryocytes. Presentation includes unexplained thrombocytopenia, petechiae and bleeding from mucosal surfaces. The spleen usually does not enlarge in size. However, splenomegaly can occur due to coexisting viral infection. Marrow examination reveals normal or increased number of megakaryocytes. Diagnosis is by exclusion of other thrombocytopenic disorders.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 69
Incorrect
-
What is expected from complete transection of the inferior gluteal nerve when it emerges from the greater sciatic foramen?
Your Answer: Adduction of the thigh would be eliminated
Correct Answer: Extension of the thigh would be the action most affected
Explanation:As the inferior gluteal nerve emerges from the greater sciatic foramen below the piriformis muscle, it divides into branches and enters the gluteus maximus muscle which extends the femur and bends the thigh in line with the body.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 70
Incorrect
-
What is the role of factor VII in coagulation?
Your Answer: Is vitamin K independent
Correct Answer: Initiates the process of coagulation in conjunction with tissue factor
Explanation:The main role of factor VII is to initiate the process of coagulation along with tissue factor (TF). TF is found in the blood vessels and is not normally exposed to the bloodstream. When a vessel is injured tissue factor is exposed to blood and circulating factor VII. Factor VII is converted to VIIa by TF.
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This question is part of the following fields:
- General
- Physiology
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Question 71
Correct
-
Passing through the lesser sciatic foramen are the:
Your Answer: Pudendal nerve
Explanation:Structures that pass through the lesser sciatic foramen include:
– the pudendal nerve
– the nerve to obturator internus
– internal pudendal artery
– the tendon of obturator internus
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 72
Incorrect
-
An enlarged lymph node which shows well-defined, prominent paracortical follicles with germinal centres is most likely from which of the following patients?
Your Answer: A 58-year-old man with Bence Jones proteins in the urine
Correct Answer: A 5-year-old boy with a sore throat and runny nose
Explanation:Lymphadenopathy is common in children and is usually reactive in nature. The description fits that of a benign, reactive lymph node.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 73
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.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 74
Correct
-
A 56-year-old woman complains of back pain, muscle spasms, weakness, and a burning sensation that radiates from her left hip to her toes. What's the most likely diagnosis?
Your Answer: Herniated nucleus pulposus
Explanation:A herniated disk will produce sensory disturbances, causing pain that radiates along the course of the sciatic nerve which is typically burning or stabbing, with or without back pain. The herniation is usually caused by age-related degeneration although trauma, injuries, or straining may also trigger it.
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This question is part of the following fields:
- Orthopaedics
- Pathology
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Question 75
Correct
-
During laparoscopic surgery to repair a direct inguinal hernia in a 68-year old man, the surgeon asked the registrar to look at the medial inguinal fossa to identify the direct inguinal hernia. To do so, she would have to look at the area that is between the:
Your Answer: Medial umbilical ligament and inferior epigastric artery
Explanation:The medial umbilical fold is made by the medial umbilical ligament-which is the obliterated portion of the umbilical artery, while the lateral umbilical fold is a fold of peritoneum over the inferior epigastric vessels. The median umbilical fold is a midline structure made by the median umbilical ligament i.e. the obliterated urachus. The medial inguinal fossa is the space on the inner abdominal wall between the medial umbilical fold and the lateral umbilical fold. It is place in the abdominal wall where there is an area of weak fascia i.e. the inguinal triangle through which direct inguinal hernias break through. The lateral inguinal fossa on the other hand is a space lateral to the lateral umbilical fold. Indirect inguinal hernias push through this space.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 76
Incorrect
-
A 40-year old woman with portal hypertension has impaired venous drainage of the anal canal above the pectinate line. Thus, there might be an increase in blood flow downward to the systemic venous system via anastomoses with the inferior rectal vein. This is a tributary of?
Your Answer: Inferior mesenteric vein
Correct Answer: Internal pudendal vein
Explanation:The inferior rectal vein drains into the internal pudendal vein. In addition the external iliac vein is one of the two branches of the common iliac vein however the internal iliac vein and it’s tributaries (including the pudendal vein) are much more important in draining the pelvic structures.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 77
Correct
-
A man had an injury to his right brachial plexus. After examination by the doctor they found that the diaphragm and the scapula were unaffected however the patient could not abduct his arm. When helped with abducting his arm to 45 degrees he was able to continue the movement. This means that he was unable to initiate abduction. Where is the likely site of injury?
Your Answer: Suprascapular nerve
Explanation:The loss of ability to initiate abduction means paralysis of the supraspinatus muscle. This muscle is supplied by the supraclavicular nerve.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 78
Correct
-
Which of the following is a landmark to identify the site of the 2nd costal cartilage?
Your Answer: Sternal angle
Explanation:The sternal angle is an important part where the second costal cartilage attaches to the sternum. Finding the sternal angle will help in finding the second costal cartilage and intercostal space.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 79
Incorrect
-
A 24 year old mother is breastfeeding her first child. Which of the following cellular adaptations occurred in her breast tissue to allow her to do this?
Your Answer: Ductal epithelial metaplasia
Correct Answer: Lobular hyperplasia
Explanation:Under the influence of oestrogen in pregnancy, there is an increase in the number of lobules which will facilitate lactation.
Steatocytes occur due to loss of weight and nutritional deficit.
Metaplasia is a normal physiological process which is due to a change in normal epithelium with another type.
Lobular atrophy will result in a decreased capacity to provide milk.
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This question is part of the following fields:
- Cell Injury & Wound Healing; Female Health
- Pathology
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Question 80
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: Ceftriaxone
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.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 81
Correct
-
A 70-year old man presents to the surgical out patient clinic with a direct inguinal hernia on the right side. He had undergone and appendicectomy 6 months prior. The examining doctor correlated the development of the hernia to iatrogenic nerve injury that happened during the operation. Which nerve had been injured?
Your Answer: Ilioinguinal
Explanation:Direct inguinal hernias occur because of weakness in the abdominal muscles. The ilioinguinal nerve is important for innervating the muscles of the lower abdominal wall and damage during appendicectomy therefore prevents the man from being able to contract abdominal muscles to pull the falx inguinalis over the weak fascia.
The genitofemoral nerve innervates the cremaster muscle and injury to it would cause inability to elevate the testes.
The subcostal nerve and the ventral primary ramus of T10 innervate the muscles, skin and fascia of the upper abdominal wall.
The iliohypogastric nerve supplies the skin over the upper part of the buttock behind the area supplied by the subcostal nerve.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 82
Correct
-
A 35-year-old woman in her 37th week of pregnancy complains of urinary incontinence. She is most likely to have:
Your Answer: Stress incontinence
Explanation:Urinary incontinence is the involuntary excretion of urine from one’s body. It is often temporary and it almost always results from an underlying medical condition. Several types include:
– Stress incontinence is the voiding of urine following increased abdominal pressure e.g. laughing, coughing, pregnancy etc. It is the most common form of incontinence in women, most commonly due to pelvic floor muscle weakness, physical changes from pregnancy, childbirth and menopause. In men it is a common problem following a prostatectomy. Most lab results such as urine analysis, cystometry and postvoid residual volume are normal.
– Urge incontinence is involuntary loss of urine occurring for no apparent reason while suddenly feeling the need or urge to urinate. The most common cause of urge incontinence are involuntary and inappropriate detrusor muscle contractions.
– Functional incontinence – occurs when a person does not recognise the need to go to the toilet, recognise where the toilet is or get to the toilet in time. The urine loss may be large. Causes of functional incontinence include confusion, dementia, poor eyesight, poor mobility, poor dexterity or unwillingness. t
– Overflow incontinence – sometimes people find that they cannot stop their bladders from constantly dribbling or continuing to dribble for some time after they have passed urine.
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This question is part of the following fields:
- Physiology
- Renal
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Question 83
Incorrect
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A 70-year old man had had a large indirect inguinal hernia for 3 years. He presents at the out patient clinic complaining of pain in the scrotum. There is, however, no evidence of obstruction or inflammation. You conclude that the hernial sac is most probably compressing the:
Your Answer: Femoral branch of the genitofemoral nerve
Correct Answer: Ilioinguinal nerve
Explanation:The ilioinguinal nerve arises together with the iliohypogastric nerve from the first lumbar nerve to emerge from the lateral border of the psoas major muscle just below the iliohypogastric and passing obliquely across the quadratus lumborum and iliacus muscles. It perforates the transversus abdominis, near the anterior part of the iliac crest and communicates with the iliohypogastric nerve between the internal oblique and the transversus. It then pierces the internal oblique to distribute filaments to it and accompanying the spermatic cord through the subcutaneous inguinal ring, is distributed to the skin of the upper and medial parts of the thigh, the skin over the root of the penis and the upper part of the scrotum in man and to the skin covering the mons pubis and labium majus in the woman. As the ilioinguinal nerve runs through the inguinal canal, it could easily be compressed by a hernial sac.
The femoral branch of genitofemoral nerve provides sensory innervation of the upper medial thigh.
The femoral nerve innervates the compartment of the thigh and also has some cutaneous sensory branches to the thigh.
The iliohypogastric nerve innervates the skin of the lower abdominal wall, upper hip and upper thigh. The subcostal nerve innervates the skin of the anterolateral abdominal wall and the anterior scrotal nerve is a terminal branch of the ilioinguinal nerve.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 84
Incorrect
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A 50-year-old man is diagnosed with emphysema and cirrhosis of the liver. Which of the following condition may be the cause of both cirrhosis and emphysema in this patient?
Your Answer: Cystic fibrosis
Correct Answer: Alpha1-antitrypsin deficiency
Explanation:Alpha-1 antitrypsin (A1AT) deficiency is a condition characterised by the lack of a protein that protects the lungs and liver from damage, called alpha1-antytripsin. The main complications of this condition are liver diseases such as cirrhosis and chronic hepatitis, due to accumulation of abnormal alpha 1-antytripsin and emphysema due to loss of the proteolytic protection of the lungs.
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This question is part of the following fields:
- Pathology
- Respiratory
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Question 85
Correct
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Where is the mental foramen located?
Your Answer: In the mandible
Explanation:The mental foramen is found bilaterally on the anterior surface of the mandible adjacent to the second premolar tooth. The mental nerve and terminal branches of the inferior alveolar nerve and mental artery leave the mandibular canal through it.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 86
Correct
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A 45-year old farmer was referred to the surgical clinic with complaints of pain in his right hypochondrium. Investigations confirmed the diagnosis of hepatocellular carcinoma with malignant ascites. According to you, what is the most likely cause of HCC in this patient?
Your Answer: Aflatoxin
Explanation:Aflatoxins are naturally occurring toxins produced by the Aspergillus fungus (most often, A. flavus and A. parasiticus). These organisms are common and their native habitat is soil, decaying vegetation and grains. They can contaminate the grain before harvest or after storage, more likely in high-humidity (at least 7%) or high temperature environment of after stressful conditions like drought. Aflatoxins are mycotoxins and also carcinogenic. They get metabolized in the liver to an epoxide, aflatoxin M1. High exposure can lead to acute necrosis, cirrhosis or liver carcinoma. These substances can cause haemorrhage, acute liver damage, oedema, and alteration in digestion, absorption and/or metabolism of nutrients. Although humans are susceptible to these toxins like all other animals, they have a high tolerance level and hence, rarely develop acute aflatoxicosis. However, children are particularly susceptible to exposure leading to growth impairment and delayed development. Chronic exposure carries a high risk of hepatic cancer, due to intercalation of its metabolite aflatoxin M1 into the DNA and alkylation of the bases because of its epoxide moiety.
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This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
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Question 87
Incorrect
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Which of the following is most likely to cause hypovolaemic hypernatremia:
Your Answer: Nephrogenic diabetes insipidus
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.
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This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
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Question 88
Correct
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Which of the following muscles attach to the hyoid bone?
Your Answer: Middle pharyngeal constrictor
Explanation:The hyoid bone is a horseshoe-shaped bone situated in the anterior midline of the neck between the chin and the thyroid cartilage. A large number of muscles attach to the hyoid: Superiorly – the middle pharyngeal constrictor muscle, hyoglossus muscle, genioglossus, intrinsic muscles of the tongue and suprahyoid muscles. Inferiorly – the thyrohyoid muscle, omohyoid muscle and sternohyoid muscle.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 89
Incorrect
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Which of the following malignancies is associated with the development of Lambert-Eaton myasthenic syndrome?
Your Answer: Malignant melanoma
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.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 90
Correct
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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: 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.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 91
Correct
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After a cerebral infarction, which of these histopathogical findings is most likely to be found?
Your Answer: Liquefactive necrosis
Explanation:The brain has a high lipid content and typically undergoes liquefaction with ischaemic injury, because it contains little connective tissue but high amounts of digestive enzymes.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 92
Incorrect
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Glucose is not secreted by the kidneys, and is filtered without a limit. What is the transport maximum for glucose?
Your Answer: 200 mg/dl
Correct Answer: 300 mg/dl
Explanation:Transport maximum (or Tm) refers to the point at which increases in concentration do not result in an increase in movement of a substance across a membrane. Glucose is not secreted, thus excretion = filtration – reabsorption. Both filtration and reabsorption are directly proportional to the concentration of glucose in the plasma. However, reabsorption has a transport maximum of about 300 mg/dl in healthy nephrons, while filtration has effectively no limit (within reasonable physiological ranges). So, if the concentration rises above 300 mg/dl, the body cannot retain all the glucose, leading to glucosuria. Glucosuria is nearly always caused by elevated blood glucose levels, most commonly due to untreated diabetes mellitus.
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This question is part of the following fields:
- Physiology
- Renal
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Question 93
Correct
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A patient sustained an injury to the facial nerve after it emerges from the stylomastoid foramen. What is the clinical impact of this injury?
Your Answer: Facial expression
Explanation:The facial nerve is the seventh of the twelve paired cranial nerves. It emerges from the brainstem between the pons and the medulla. It controls the muscles of facial expression and supplies taste fibres to the anterior two-thirds of the tongue. It also supplies preganglionic parasympathetic fibres to several head and neck ganglia. Its branches and distribution are as follows:
Inside the facial canal (proximal to the stylomastoid foramen):
– Greater petrosal nerve – provides parasympathetic innervation to the lacrimal gland, as well as special taste sensory fibres to the palate via the nerve of pterygoid canal
– Nerve to stapedius – provides motor innervation for the stapedius muscle in the middle ear
– Chord tympani – provides parasympathetic innervation to the submandibular and sublingual glands and special sensory taste fibres for the anterior two-thirds of the tongue
Outside the skull (distal to the stylomastoid foramen):
– Posterior auricular nerve – controls the movements of some of the scalp muscles around the ear
– Five major facial branches (in the parotid gland), from top to bottom: temporal branch, zygomatic branch, buccal branch, marginal mandibular branch and cervical branch. From the description given above it is obvious that injury to the facial nerve distal to the stylomastoid foramen will affect facial expression.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 94
Correct
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Regarding innervation to the peroneus brevis muscle:
Your Answer: Could be damaged by a fracture of the neck of the fibula
Explanation:The peroneus brevis is supplied by the fourth and fifth lumbar and first sacral nerves through the superficial peroneal nerve which is one of the two terminal branches of the common peroneal nerve. The common peroneal nerve winds around the neck of the fibula and can be injured in cases of fractured neck of fibula.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 95
Correct
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Which of these illnesses is most likely to precede Guillain-Barré syndrome?
Your Answer: Viral pneumonia
Explanation:Guillain–Barré syndrome (GBS) is characterized by a rapid-onset muscle weakness caused by the immune system damaging the peripheral nervous system. In about two-thirds of patients, the syndrome begins 5 days to 3 weeks after an infectious disease, surgery or vaccination. Infection is the trigger in over 50% of patients; common pathogens include Campylobacter jejuni, enteric viruses, herpesviruses (including cytomegalovirus and those causing infectious mononucleosis) and Mycoplasma species. The underlying mechanism involves an autoimmune disorder in which the body’s immune system mistakenly attacks the peripheral nerves and damages their myelin insulation, although the cause for this is still unknown.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 96
Incorrect
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Which of the following statements regarding the arteries in the neck are TRUE?
Your Answer: The carotid sinus is located below the origin of the external carotid artery
Correct Answer: The thyrocervical trunk typically gives rise to the inferior thyroid artery, transverse cervical artery and suprascapular artery
Explanation:The thyrocervical trunk is one of the three branches of the first part of the subclavian artery and gives numerous branches which supply viscera of the neck, the brachial plexus, neck muscles and scapular anastomoses. The vertebral arteries are major arteries of the neck. They arise as branches from the subclavian arteries and merge to form the single midline basilar artery. The carotid sinus is a dilated area at the base of the internal carotid artery just superior to the bifurcation of the internal carotid and external carotid at the level of the superior border of thyroid cartilage.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 97
Correct
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Which of the following is the cause of flattened (notched) T waves on electrocardiogram (ECG)?
Your Answer: Hypokalaemia
Explanation:The T-wave is formed due to ventricular repolarisation. Normally, it is seen as a positive wave. It can be normally inverted (negative) in V1 (occasionally in V2-3 in African-Americans/Afro-Caribbeans). Hyperacute T-waves are the earliest ECG change of acute myocardial infarction. ECG findings of hyperkalaemia include high, tent-shaped T-waves, a small P-wave and a wide QRS complex. Hypokalaemia results in flattened (notched) T-waves, U-waves, ST-segment depression and prolonged QT interval.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 98
Correct
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A 5-year-old child diagnosed with nephrotic syndrome developed generalised oedema. What is the mechanism for the development of oedema in patients with nephrotic syndrome?
Your Answer: Decreased colloid osmotic pressure
Explanation:The development of oedema in nephrotic syndrome has traditionally been viewed as an underfill mechanism. According to this view, urinary loss of protein results in hypoalbuminemia and decreased plasma oncotic pressure. As a result, plasma water translocates out of the intravascular space and results in a decrease in intravascular volume. In response to the underfilled circulation, effector mechanisms are then activated that signal the kidney to secondarily retain salt and water. While an underfill mechanism may be responsible for oedema formation in a minority of patients, recent clinical and experimental findings would suggest that oedema formation in most nephrotic patients is the result of primary salt retention. Direct measurements of blood and plasma volume or measurement of neurohumoral markers that indirectly reflect effective circulatory volume are mostly consistent with either euvolemia or a volume expanded state. The ability to maintain plasma volume in the setting of a decreased plasma oncotic pressure is achieved by alterations in transcapillary exchange mechanisms known to occur in the setting of hypoalbuminemia that limit excessive capillary fluid filtration.
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This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
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Question 99
Correct
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A chef, whilst preparing food, cut her thumb with a knife. She transected the arteria princeps pollicis. This artery is a branch of the?
Your Answer: Radial artery
Explanation:The radial artery branches into the arteria princeps pollicis as it turns medially into the deep part of the hand. The arteria princeps pollicis is distributed to the skin and subcutaneous tissue of the thumb.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 100
Incorrect
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A 37-year-old woman with a history of rheumatic heart disease presents with 10 days recurrent low fever. Patient underwent laboratory work up and was diagnosed with infective endocarditis. What is the most likely organism that caused the infective endocarditis in this patient?
Your Answer: Streptococcus pneumoniae
Correct Answer: Streptococcus viridans
Explanation:Subacute bacterial endocarditis is often due to streptococci of low virulence, mainly streptococcus viridans. It is a mild to moderate illness which progresses slowly over weeks and months (>2weeks) and has low propensity to hematogenously seed to extracardiac sites.
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This question is part of the following fields:
- Microbiology
- Pathology
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SESSION STATS - PERFORMANCE PER SPECIALTY
