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Question 1
Correct
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A 33-year-old female, who recently returned from a trip to Bangladesh, presents to the infectious diseases clinic with complaints of productive cough with blood-stained sputum, night sweats, and weight loss for the past one month. Based on the history and examination findings, you suspect pulmonary tuberculosis. Which ONE of the following investigations is most appropriate to make a diagnosis of active tuberculosis?
Your Answer: Sputum for acid-fast bacilli smear
Explanation:Multiple investigations may be done to establish a diagnosis of active tuberculosis. In this case, sputum for acid-fast bacilli would be the best option as it can be done immediately, give fast results, and promptly initiate treatment. Three-morning sputum samples are collected and tested for acid-fast bacilli using gram staining. Blood culture would yield results in tuberculous bacteraemia and would be less sensitive than sputum testing. A chest X-ray would not differentiate active tuberculosis from an old infection in which the Ghon complex has formed, and the body’s immune reaction contains the Mycobacterium tuberculosis bacteria. Mantoux test shows the presence of antibodies to tuberculosis and may be positive if the patient has had a previous infection or been vaccinated against tuberculosis. A CT chest would also be unable to differentiate between an active infection and the findings of old tuberculosis infection.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 2
Incorrect
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Regarding the lung roots, which of the following statements is CORRECT:
Your Answer: The phrenic nerves pass immediately posterior to the lung roots.
Correct Answer: Generally the pulmonary arteries lie superior to the pulmonary veins in the lung root.
Explanation:Each lung root contains a pulmonary artery, two pulmonary veins, a main bronchus, bronchial vessels, nerves and lymphatics. Generally the pulmonary artery is superior in the lung root, the pulmonary veins are inferior and the bronchi are somewhat posterior in position. The vagus nerves pass posterior to the lung roots while the phrenic nerves pass anterior to them.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 3
Incorrect
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Identify the type of graph described below:This graph has been used to create visual representations to communicate the risks and benefits of treatments using 4 face categories.
Your Answer: Kaplan-Meier plot
Correct Answer: Cates plot
Explanation:Cates Plot, since 1999, has been used to create visual representations to communicate the risks and benefits of treatments. The essence of Cates Plot is the use of 4 face categories to visually indicate the following:People not affected by a treatment (green faces for those with a good outcome and red for those with a bad outcome)People for which treatment changes their category from a bad outcome to a good outcome (yellow faces)People for which treatment causes an adverse event and changes their category from a good outcome to a bad outcome (crossed out green faces)
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This question is part of the following fields:
- Evidence Based Medicine
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Question 4
Incorrect
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Which of the following is true about the extensor carpi radialis longus?
Your Answer: It assists with flexion of the hand at the wrist
Correct Answer: It assists with abduction of the hand at the wrist
Explanation:The majority of extensor carpi radialis longus originates from the lateral supracondylar ridge of humerus (distal third) and anterior aspect of the lateral intermuscular septum of the arm. A small portion of its fibres originate from the common extensor tendon attached to the lateral epicondyle of humerus. The fibres unite into a muscle belly which extends approximately to the middle of the forearm. The muscle belly is then replaced by a flat tendon that travels distally along the lateral surface of the radius, together with the tendon of extensor carpi radialis brevis. Both tendons course towards the radial styloid process, deep to the tendons of abductor pollicis longus and extensor pollicis brevis muscles. Proximal to the wrist, the tendons of extensor carpi radialis longus and brevis pass behind the radial styloid process within a common synovial sheath and continue along the radial groove deep to the extensor retinaculum of the wrist. At this level, the tendon of extensor carpi radialis longus is crossed by the tendon of extensor pollicis longus, after which it inserts on the posterior aspect of the base of the second metacarpal bone. Some tendon slips can insert into the first and third metacarpal bones.Extensor carpi radialis longus receives innervation from the radial nerve, with contributions mainly from spinal nerves C5-C8. The radial nerve is a branch of the brachial plexus.Extensor carpi radialis longus receives blood supply mainly from the radial artery. It directly supplies the distal part of the muscle, while the rest of the muscle receives blood from one of its radial recurrent branches. The brachial artery also supplies a small portion of the muscle via the radial collateral artery.Extensor carpi radialis longus primarily acts on the wrist joint to produce two major actions: (1) wrist extension by working synergistically with extensor carpi radialis brevis and extensor carpi ulnaris, and (2) hand abduction (radial deviation), with the help of flexor carpi radialis.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 5
Correct
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Which of the following is NOT an effect of cytokine activity:
Your Answer: Opsonisation of bacteria for phagocytosis
Explanation:Cytokines are a family of chemical messengers, secreted by leucocytes, that act over short distances by binding specific receptors on target cell surfaces. They include: interleukins (act between leucocytes), interferons (inhibit replication of viruses within cells and activate macrophages and natural killer cells), growth factors, and tumour necrosis factors (kill tumour cells). Effects include: induction of fever and acute phase response, stimulation of leucocyte differentiation and maturation, leucocyte recruitment and activation and increased antibody production.
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This question is part of the following fields:
- Inflammatory Responses
- Pathology
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Question 6
Incorrect
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Angiotensin II acts to cause all but which one of the following effects:
Your Answer: Stimulate the sensation of thirst
Correct Answer: Inhibit release of ADH from the posterior pituitary gland
Explanation:Angiotensin II acts to:Stimulate release of aldosterone from the zona glomerulosa of the adrenal cortex (which in turn acts to increase sodium reabsorption)Cause systemic vasoconstrictionCause vasoconstriction of the renal arterioles (predominant efferent effect thus intraglomerular pressure is stable or increased, thereby tending to maintain or even raise the GFR)Directly increase Na+reabsorption from the proximal tubule (by activating Na+/H+antiporters)Stimulate synthesis and release of ADH from the hypothalamus and posterior pituitary respectivelyStimulate the sensation of thirstPotentiate sympathetic activity (positive feedback)Inhibit renin production by granular cells (negative feedback)
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This question is part of the following fields:
- Physiology
- Renal
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Question 7
Incorrect
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A 49-year-old woman with haemoglobin of 6 g/dL following persistent vaginal bleeding receives blood transfusion. She developed pain and burning at her cannula site and complains of a feeling of “impending doom”, nausea, and severe back pain shortly after transfusion was started. Her temperature is 38.9ºC.What is the most appropriate treatment?
Your Answer: Supportive measures and paracetamol
Correct Answer: Stop the transfusion and administer IV fluids
Explanation:Acute haemolytic transfusion reactions present with: Feeling of ‘impending doom’ as the earliest symptom, fever and chills, pain and warmth at transfusion site, nausea and vomiting, back, joint, and chest pain. Transfusion should be stopped immediately and IV fluid (usually normal saline) administered.Supportive measures and paracetamol can be given since patient has fever but it is not the immediate first step.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 8
Incorrect
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Which of the following is the most potent stimulus of fibrinolysis:
Your Answer: Antithrombin
Correct Answer: Tissue plasminogen activator
Explanation:Fibrinolysis is a normal haemostatic response to vascular injury. Plasminogen, a proenzyme in blood and tissue fluid, is converted to plasmin by activators either from the vessel wall (intrinsic activation) or from the tissues (extrinsic activation). The most important route follows the release of tissue plasminogen activator (TPA) from endothelial cells.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 9
Correct
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Which of the following muscles are primarily involved in passive inspiration:
Your Answer: Diaphragm and external intercostal muscles
Explanation:Passive inspiration is produced by contraction of the diaphragm (depressing the diaphragm) and the external intercostal muscles (elevating the ribs). In inspiration, elevation of the sternal ends of the ribs (‘pump handle’ movement), elevation of the lateral shafts of the ribs (‘bucket handle’ movement) and depression of the diaphragm result in expansion of the thorax in an anteroposterior, transverse and vertical direction respectively. This results in an increased intrathoracic volume and decreased intrathoracic pressure and thus air is drawn into the lungs.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 10
Incorrect
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Blood flows from the left atrium into the left ventricle via:
Your Answer: The tricuspid valve
Correct Answer: The mitral valve
Explanation:Blood flows from the right atrium into the right ventricle via the tricuspid atrioventricular valve and from the left atrium into the left ventricle via the mitral atrioventricular valve. Blood is ejected from the right ventricle through the pulmonary semilunar valve into the pulmonary artery and from the left ventricle via the aortic semilunar valve into the aorta.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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