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Question 1
Incorrect
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Humoral immunity is a major defence against:
Your Answer: Bacterial infections
Correct Answer: Viral infections
Explanation:Humoral immunity is provided by the neutralizing and non-neutralizing antibodies that are formed from the B lymphocytes. This form of immunity is most important in viral infection. Non-neutralizing antibodies increases phagocytosis of the infected cell and inhibit the ability of the virus to replicate.
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This question is part of the following fields:
- Immunology
- Medicine
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Question 2
Incorrect
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Regarding cardiac output, an increased ejection fraction results from increases in which of the following?
Your Answer: Parasympathetic stimulation
Correct Answer: Strength of contraction without increase in muscle fiber length
Explanation:When the strength of contraction increases without an increase in fiber length, the EF increases.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 3
Incorrect
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The axons of the POST ganglionic neurons are mostly?
Your Answer: E fibers
Correct Answer: C fibers
Explanation:According to Erlanger- Grasser classification preganglionic fibers are B fibers whereas post ganglionic fibers are C fibers.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 4
Incorrect
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A study is developed to look at the potential of hip protectors to reduce femoral neck fractures in elderly nursing home patients. The study included 800 patients randomly selected with an average age of 82 years of age. The data was collected over a two year period and the patients were randomly put in the standard care group or the hip protector group. From the 400 patients assigned to the hip protector group, 10 had a femoral neck fracture over the two year period. From the 400 patients assigned to the standard care group, 20 had a femoral neck fracture over the two year period. What is the correct value regarding the absolute risk reduction?
Your Answer: 2
Correct Answer: 0.025
Explanation:Absolute risk reduction (ARR) – also called risk difference (RD) – is the most useful way of presenting research results to help your decision-making. In this example, the ARR is 8 per cent (20 per cent – 12 per cent = 8 per cent). This means that, if 100 children were treated, 8 would be prevented from developing bad outcomes. Another way of expressing this is the number needed to treat (NNT). If 8 children out of 100 benefit from treatment, the NNT for one child to benefit is about 13 (100 ÷ 8 = 12.5). CER = 20 / 400 = 1 / 20 = 0.05, EER = 10 / 400 = 0.025, ARR =CER – EER = 0.025
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This question is part of the following fields:
- Medicine
- Research Skills
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Question 5
Incorrect
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Depolarization of the T tubule membrane activates the sarcoplasmic reticulum via which receptors?
Your Answer: Alpha receptors
Correct Answer: Dihydropyridine receptors
Explanation:Action potentials are transmitted to the fibrils of a fiber through the T tubule system. It triggers the release of Ca 2+ form the terminal cisterns. Depolarization of the T tubules activates the sarcoplasmic reticulum through the dihydropyridine receptors.
Dihydropyridine receptors (DHPRs), are voltage-gated Ca2+ channels, and ryanodine receptors (RyRs), which are intracellular Ca2+ release channels, are expressed in diverse cell types, including skeletal and cardiac muscle.
Ryanodine receptors (RyRs) are located in the sarcoplasmic/endoplasmic reticulum membrane and are responsible for the release of Ca2+ from intracellular stores during excitation-contraction coupling in both cardiac and skeletal muscle.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 6
Incorrect
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Which membrane bound protein in the sarcoplasmic reticulum regulates calcium return from the cytosol to the sarcoplasmic reticulum?
Your Answer:
Correct Answer: Phospholamban
Explanation:Phosphorylation of phospholamban increases calcium ATPase activity and sequestration of calcium in the sarcoplasmic reticulum. An increased rate of relaxation is explained because cAMP also activates the protein phospholamban, situated on the membrane of the sarcoplasmic reticulum (SR), that controls the rate of uptake of calcium into the SR. The latter effect explains enhanced relaxation (lusitropic effect).
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 7
Incorrect
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Question 8
Incorrect
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Which of the following drugs is NOT bacteriostatic?
Your Answer:
Correct Answer: Penicillin
Explanation:Bactericidal antibiotics kill bacteria directly whereas bacteriostatic antibiotics slow their growth or reproduction. Tetracycline is a bacteriostatic antibiotic. Erythromycin which is a macrolide is mainly a bacteriostatic antibiotic but can show bactericidal action depending on the dose. Sulphonamides are mainly bacteriostatic. Penicillin inhibits cell wall synthesis therefore it is considered as bactericidal. Chloramphenicol is primarily a bacteriostatic antibiotic which inhibits protein synthesis and can exhibit bactericidal action in high concentrations.
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This question is part of the following fields:
- Infectious Diseases
- Medicine
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Question 9
Incorrect
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The direct determinants of cardiac output are
Your Answer:
Correct Answer: Stroke volume and heart rate
Explanation:Cardiac output is classically defined alongside stroke volume (SV) and the heart rate (HR) as:Cardiac Output [L/min] = Stroke Volume [L/beat] x Heart Rate [beats/min]
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 10
Incorrect
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Which of the following features is least commonly seen in Gitelman’s syndrome?
Your Answer:
Correct Answer: Hypertension
Explanation:Gitelman syndrome is an autosomal recessive kidney disorder characterized by hypokalaemia metabolic alkalosis with hypocalciuria, and hypomagnesemia. In contrast to patients with Gordon’s syndrome, those suffering from Gitelman’s syndrome are generally normotensive or hypotensive.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 11
Incorrect
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During anaerobic glycolysis, the net production of ATP is:
Your Answer:
Correct Answer: 2
Explanation:Anaerobic glycolysis is the transformation of glucose to lactate when limited amounts of oxygen (O2) are available. Anaerobic glycolysis is only an effective means of energy production during short, intense exercise, providing energy for a period ranging from 10 seconds to 2 minutes. It produces 2 ATP molecules per glucose molecule.
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This question is part of the following fields:
- Medicine
- Metabolism
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Question 12
Incorrect
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Which of the following limits the duration of inspiration and increases respiratory rate?
Your Answer:
Correct Answer: Pneumotaxic centre
Explanation:The mechanism of control of ventilation is an interplay of multiple regions in the brain. The medullary respiratory centre sets the basic rhythm of breathing and the pons modifies the output of the medullary centres. There are two pontine centres: apneustic and pneumotaxic.
The pnuemotaxic centre controls inspiratory time. Increased signals to this area increases respiratory rate. The dorsal respiratory group (DRG) integrates input from the stretch receptors and the chemoreceptors in the periphery and is composed mainly of inspiratory neurons. The DRG controls the basic rhythm of breathing by triggering inspiratory impulses. The ventral respiratory group (VRG) generates breathing rhythm and integrates data coming into the medulla and contains both inspiratory and expiratory neurons. They are primarily active in exercise and stress.
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This question is part of the following fields:
- Medicine
- Respiratory
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Question 13
Incorrect
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The following is true in relation to coronary venous drainage?
Your Answer:
Correct Answer: Most venous return ultimately drains into right atrium via the coronary sinus
Explanation:Most of the venous blood returns to the heart via the coronary sinus and the anterior cardiac veins. Apart from these there are other vessels that drain directly into the heart chambers
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 14
Incorrect
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Erythropoietin is synthesized by which cells of the nephron?
Your Answer:
Correct Answer: Tubular interstitial cells
Explanation:Erythropoietin is produced by interstitial fibroblasts in the kidney in close association with peritubular capillary and proximal convoluted tubule. It is also produced in perisinusoidal cells in the liver. While liver production predominates in the fetal and perinatal period, renal production is predominant during adulthood.
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This question is part of the following fields:
- Medicine
- Renal
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Question 15
Incorrect
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Which are the main hormones secreted by the posterior pituitary gland.
Your Answer:
Correct Answer: Oxytocin and vasopressin
Explanation:The posterior pituitary gland secretes oxytocin and vasopressin (antidiuretic hormone). These hormones are stored in Herring bodies before being secreted into the bloodstream.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 16
Incorrect
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A 28 year old female presents to the rheumatology clinic for review. She has a history of adult onset Still's disease and complains of joint pains and persistent skin rash despite undergoing treatment with methotrexate and etanercept. On examination, an erythematous macular rash and active synovitis is noted. CRP is high (95 mg/dl). Which of the following interventions would be most appropriate?
Your Answer:
Correct Answer: Anakinra
Explanation:Adult onset Still’s disease (AOSD) is an uncommon systemic inflammatory disease on the clinical spectrum of autoinflammatory disorders. Its presentation and clinical course may result in several well-differentiated phenotypes: from a systemic and highly symptomatic pattern to a chronic articular pattern. Overproduction of numerous pro-inflammatory cytokines is observed in AOSD. Anakinra, a human interleukin (IL)-1R antagonist, has recently been approved in the treatment of AOSD. Denosumab is a RANK ligand inhibitor used in the treatment of osteoporosis. Mepolizumab is used in the treatment of severe asthma with elevated eosinophils. There is some evidence to support the use of tocilizumab, an anti-IL6 monoclonal antibody in adult onset Still’s, but there is stronger data favouring the use of tocilizumab in the treatment of rheumatoid arthritis. Rituximab is usually reserved for patients who are unresponsive to anakinra.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 17
Incorrect
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Question 18
Incorrect
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Which cells produce the immunoglobulin proteins involved in mediating humoral immunity?
Your Answer:
Correct Answer: Differentiated forms of B lymphocytes known as plasma cells
Explanation:After the B cells have been activated by a certain antigens, they transform into plasma cells. These plasma cells are responsible for the generation of antibodies (or immunoglobulins Ig) which are also known as regulators of humoral immunity. There are fives classes of Ig: IgA, IgG, IgM, IgE and IgD
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This question is part of the following fields:
- Immunology
- Medicine
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Question 19
Incorrect
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Where does the SA node develop?
Your Answer:
Correct Answer: From structures on the right side of the embryo.
Explanation:The SA node develops from the right side of the embryo and the AV node from the left. This is the reason why in adults the right vagus supplies the SA node and the left vagus supplies the AV node.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 20
Incorrect
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A 60 year old male presents with thickened patches of skin over his knuckles and extensor surfaces that are consistent with Gottron's papules. Results reveal an elevated creatine kinase. Diagnosis of dermatomyositis is suspected. Which of the following autoantibody is most specific for this condition?
Your Answer:
Correct Answer: Anti-Mi-2 antibodies
Explanation:Anti–Mi-2 antibodies are highly specific for dermatomyositis, but sensitivity is low; only 25% of patients with dermatomyositis demonstrate these antibodies. A positive antinuclear antibody (ANA) finding is common in patients with dermatomyositis, but is not necessary for diagnosis. Anti-Jo-1 antibodies are mostly associated with polymyositis. Anti Scl-70 antibodies and anti centromere antibodies are most commonly found in systemic scleroderma.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 21
Incorrect
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A 28 year old male arrives at the clinic complaining of fever, arthralgia and urethritis. On examination, the ankle is swollen and there is a pustular rash on the dorsal foot. What is the most likely diagnosis?
Your Answer:
Correct Answer: Disseminated gonorrhoea
Explanation:DGI presents as two syndromes: 1) a bacteremic form that includes a triad of tenosynovitis, dermatitis, and polyarthralgias without purulent arthritis and 2) a septic arthritis form characterized as a purulent arthritis without associated skin lesions. Many patients will have overlapping features of both syndromes. Time from infection to clinical manifestations may range from 1 day to 3 months. There is no travel history and the rash of Lyme disease is not purulent. Reactive arthritis presents with conjunctivitis, urethritis and arthritis usually with a red hot tender and swollen joint.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 22
Incorrect
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Which of the flowing plasma proteins has the greatest affinity for T4?
Your Answer:
Correct Answer: Thyroxin-binding globulin
Explanation:There are three principal plasma thyroid hormone-binding proteins, thyroxine-binding globulin (TBG), transthyretin (TTR), and albumin. TBG is synthesized in the liver and due to its relatively high affinity for iodothyronines, binds and carries approximately 70–75% of circulating T4 and T3.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 23
Incorrect
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The process where by DNA fragments are separated by size and charge is called:
Your Answer:
Correct Answer: Gel electrophoresis
Explanation:Fragments of DNA of varying length can be separated on the basis of their charge and their size by a process called gel electrophoresis. Because DNA contains negatively charged phosphate groups, it will migrate in an electric field toward the positive electrode. Shorter chains migrate more rapidly through the pores of the gel, and thus separation depends on length. DNA bands in the gel can be visualized by various techniques including staining with dyes and autoradiography.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 24
Incorrect
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The conversion of haem to bilirubin is catalysed by which of these enzymes?
Your Answer:
Correct Answer: Biliverdin reductase
Explanation:Bilirubin is created by the activity of biliverdin reductase on biliverdin, a green tetrapyrrolic bile pigment that is also a product of haem catabolism.
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This question is part of the following fields:
- Hepatobiliary
- Medicine
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Question 25
Incorrect
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Absolute refractory period in a cardiac action potential graph occurs during.
Your Answer:
Correct Answer: All of the above
Explanation:Absolute refractory period (ARP): the cell is completely unexcitable to a new stimulus and occurs from phase 0 – 2 i.e. depolarisation, early repolarisation and plateau phase.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 26
Incorrect
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Regarding bronchial innervation which of the following is correct:
Your Answer:
Correct Answer: Alpha 1 receptors increase bronchial constriction
Explanation:Stimulation of β2 receptors results in smooth muscle relaxation and bronchodilation. α1 receptors cause smooth muscle contraction in the bronchioles although minor to the β2 effects.
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This question is part of the following fields:
- Medicine
- Respiratory
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Question 27
Incorrect
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Question 28
Incorrect
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All of the following are consistent with the indicator dilution method except---
Your Answer:
Correct Answer: In thermodilution, the indicator used is warm saline
Explanation:In thermodilution, the indicator used is cold saline.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 29
Incorrect
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Question 30
Incorrect
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Which of the following is NOT an effect of a positive inotropic agent on the heart?
Your Answer:
Correct Answer: It decreases the rate of rise in ventricular blood pressure during systole
Explanation:Inotropic agents increase the contractility of the heart as well as the rate of rise in ventricular blood pressure during systole, generating a greater pressure and increasing the stroke volume e.g. like catecholamines do.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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SESSION STATS - PERFORMANCE PER SPECIALTY
