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Question 1
Correct
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A patient is diagnosed as having a glucagonoma. Her blood serum glucagon concentration is 1246 pg/mL.Glucagon INHIBITS which of the following processes? Select ONE answer only.
Your Answer: Glycolysis
Explanation:Glucagon is a peptide hormone that is produced and secreted by alpha cells of the islets of Langerhans, which are located in the endocrine portion of the pancreas. The main physiological role of glucagon is to stimulate hepatic glucose output, thereby leading to increases in glycaemia. It provides the major counter-regulatory mechanism to insulin in maintaining glucose homeostasis.Hypoglycaemia is the principal stimulus for the secretion of glucagon but may also be used as an antidote in beta-blocker overdose and in anaphylaxis in patients on beta-blockers that fail to respond to adrenaline. Glucagon then causes:GlycogenolysisGluconeogenesisLipolysis in adipose tissueThe secretion of glucagon is also stimulated by:AdrenalineCholecystokininArginineAlanineAcetylcholineThe secretion of glucagon is inhibited by:InsulinSomatostatinIncreased free fatty acidsIncreased urea productionGlycolysis is the metabolic pathway that converts glucose into pyruvate. The free energy released by this process is used to form ATP and NADH. Glycolysis is inhibited by glucagon, and glycolysis and gluconeogenesis are reciprocally regulated so that when one cell pathway is activated, the other is inactive and vice versa.Glucagon has a minor effect of enhancing lipolysis in adipose tissue. Lipolysis is the breakdown of lipids and involves the hydrolysis of triglycerides into glycerol and free fatty acids. It makes fatty acids available for oxidation.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 2
Incorrect
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Which of the following hormones regulates Na+reabsorption in the proximal tubule:
Your Answer: Atrial natriuretic peptide
Correct Answer: Angiotensin II
Explanation:Angiotensin II increases Na+reabsorption from the proximal tubule (by activating Na+/H+antiporters).
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This question is part of the following fields:
- Physiology
- Renal
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Question 3
Correct
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A patient with abdominal pain, vomiting and bloody diarrhoea develops a low platelet count and deranged renal function. A diagnosis of haemolytic uraemic syndrome is made.Which of the following organisms is a recognised cause of haemolytic uraemic syndrome? Select ONE answer only.
Your Answer: Escherichia coli
Explanation:E.Colistrain 0157 causes enterohaemorrhagic diarrhoea and can be followed by haemolytic uraemic syndrome (renal failure, haemolytic anaemia and thrombocytopenia).
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 4
Incorrect
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Lidocaine's antiarrhythmic mode of action is as follows:
Your Answer: Blocks L-type calcium channels
Correct Answer: Blocks inactivated Na+ channels
Explanation:Lidocaine is a class 1B antidysrhythmic; combines with fast Na channels and thereby inhibits recovery after repolarization, resulting in decreasing myocardial excitability and conduction velocity. However, in ischaemic areas, where anoxia causes depolarisation and arrhythmogenic activity, many Na+ channels are inactivated and therefore susceptible to lidocaine.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 5
Incorrect
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Which of these statements about experimental studies is true?
Your Answer: Patients can only receive treatment or placebo
Correct Answer: Randomisation serves to remove potential bias
Explanation:In experimental studies, the researcher introduces an intervention and studies the effect. The study subjects are allocated into different groups by the investigator through the use of randomisation. Randomisation serves to remove any potential bias.A cohort study is a form of longitudinal, observational study that follows a group of patients (the cohort) over a period of time to monitor the effects of exposure to a proposed aetiological factor upon them.A case-control study is a type observational study. Here, patients who have developed a disease are identified and compared on the basis of proposed causative factors that occurred in the past, to a control group.Clinical trials are experimental studies. Examples include: double blind, single blind, and unblinded studies(both patient and researcher are aware of the treatment they receive)
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This question is part of the following fields:
- Evidence Based Medicine
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Question 6
Correct
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A 33-year-old woman who is investigated for recurrent renal stones is discovered to have a markedly elevated parathyroid hormone (PTH) level.Which of the following would stimulate PTH release under normal circumstances? Select ONE answer only.
Your Answer: Decreased plasma calcium concentration
Explanation:Parathyroid hormone (PTH) is a polypeptide containing 84 amino acids. It is the principal controller of free calcium in the body.PTH is synthesised by and released from the chief cells of the four parathyroid glands that are located immediately behind the thyroid gland.PTH is released in response to the following stimuli:Decreased plasma calcium concentrationIncreased plasma phosphate concentration (indirectly by binding to plasma calcium and reducing the calcium concentration)PTH release is inhibited by the following factors:Normal/increased plasma calcium concentrationHypomagnesaemiaThe main actions of PTH are:Increases plasma calcium concentrationDecreases plasma phosphate concentrationIncreases osteoclastic activity (increasing calcium and phosphate resorption from bone)Increases renal tubular reabsorption of calciumDecreases renal phosphate reabsorptionIncreases renal conversion of 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol (via stimulation of 1-alpha hydroxylase)Increases calcium and phosphate absorption in the small intestine (indirectly via increased 1,25-dihydroxycholecalciferol)
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 7
Correct
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After collapsing at home, a 62-year-old man is transported in an ambulance. He is now awake, but he is experiencing palpitations and chest pain. He is rushed to resuscitation and placed on a cardiac monitor, which reveals ventricular tachycardia. An amiodarone infusion is set up.Which of these statements about amiodarone is correct?
Your Answer: It is expressed in breast milk
Explanation:Antiarrhythmic drug amiodarone is used to treat both ventricular and atrial arrhythmias. It’s a class III antiarrhythmic that works by prolonging the repolarization phase of the cardiac action potential, where potassium permeability is normally high and calcium permeability is low.Dronedarone is sometimes used instead of amiodarone in certain situations. Although amiodarone is more effective than dronedarone, dronedarone has fewer side effects.Grapefruit juice inhibits the metabolism of amiodarone.The plasma half-life of amiodarone is very long, ranging from 2 weeks to 5 months. The half-life is about 2 months on average.Because amiodarone is excreted in breast milk, it should be avoided by breastfeeding mothers.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 8
Incorrect
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Which of the following is NOT a common side effect of antihistamines:
Your Answer:
Correct Answer: Tremor
Explanation:Common side effects of antihistamines may include:Anticholinergic effects (blurred vision, dry mouth, urinary retention)HeadacheGastrointestinal disturbancesPsychomotor impairment (sedation, dizziness and loss of appetite)These side effects are significantly reduced with second-generation agents.
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 9
Incorrect
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A young male has presented to you with respiratory depression and small pupils on examination. You diagnose opioid overdose and immediately start therapy with Naloxone.Which of the following statements is TRUE regarding naloxone?
Your Answer:
Correct Answer: It can be given by a continuous infusion if repeated doses are required
Explanation:Naloxone is a short-acting, specific antagonist of mu(μ)-opioid receptors. It is used to reverse the effects of opioid toxicity. It can be given by a continuous infusion if repeated doses are required and the infusion rate is adjusted according to the vital signs. Initially, the infusion rate can be set at 60% of the initial resuscitative IV dose per hour.Naloxone has a shorter duration of action (6-24 hours) than most opioids and so close monitoring according to the respiratory rate and depth of coma and repeated injections are necessary. When repeated doses are needed in opioid addicts, naloxone administration may precipitate a withdrawal syndrome with abdominal cramps, nausea and diarrhoea, but these usually settle within 2 hours.An initial dose of 0.4 to 2 mg can be given intravenously and can be repeated at 2 to 3-minute intervals to a maximum of 10mg. If the intravenous route is inaccessible, naloxone can be administered via an IO line, subcutaneously (SQ), IM, or via the intranasal (IN) route.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 10
Incorrect
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You examine a 78-year-old man who has been diagnosed with chronic lymphocytic leukaemia (CLL).What is the MAIN contributory factor in this condition's immunodeficiency?
Your Answer:
Correct Answer: Hypogammaglobulinemia
Explanation:Immunodeficiency is present in all patients with chronic lymphocytic leukaemia (CLL), though it is often mild and not clinically significant. Infections are the leading cause of death in 25-50 percent of CLL patients, with respiratory tract, skin, and urinary tract infections being the most common.Hypogammaglobulinemia is the most common cause of immunodeficiency in CLL patients, accounting for about 85 percent of all cases.
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This question is part of the following fields:
- Haematology
- Pathology
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SESSION STATS - PERFORMANCE PER SPECIALTY
