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Question 1
Correct
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Atrial natriuretic peptide (ANP) is primarily produced in response to:
Your Answer: An increase in intravascular fluid volume
Explanation:Atrial natriuretic peptide (ANP) is released from cardiac atrial muscle cells in response to atrial stretch caused by an increase in intravascular fluid volume and is also produced in collecting duct cells.Atrial natriuretic peptide acts to inhibit sodium reabsorption in the distal nephron.
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This question is part of the following fields:
- Physiology
- Renal
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Question 2
Correct
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Glucagon is secreted by which of the following pancreatic cell types:
Your Answer: α cells
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
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Question 3
Correct
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Which of the following drugs decreases plasma-theophylline levels:
Your Answer: Carbamazepine
Explanation:Examples of enzyme-inhibiting drugs (raise plasma theophylline level):ErythromycinClarithromycinCiprofloxacinFluconazoleVerapamilAllopurinolCimetidineExamples of enzyme-inducing drugs (lower plasma theophylline level):PrimidonePhenobarbitalCarbamazepinePhenytoinRitonavirRifampicinSt John’s Wort
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 4
Incorrect
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Which of the following muscles is most responsible for thigh extension at the hip joint?
Your Answer: Hamstrings, gluteus medius and gluteus minimus
Correct Answer: Hamstrings and gluteus maximus
Explanation:For hip extension, the gluteus maximus and hamstring muscles work together. To compensate for gluteus maximus weakness, the hamstring frequently acts as the primary hip extensor.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 5
Incorrect
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A 30-year-old female presented to the Emergency Department after a fall during a hiking expedition caused severe pain in her left arm and wrist drop. An X-ray revealed a mid-shaft fracture of the humerus, which most likely damaged the radial nerve. Which one of the following statements best describes the healing process of peripheral nerves?
Your Answer: Schwann cells are associated only with myelinated nerve fibres
Correct Answer: Peripheral nerve fibres regenerate at around 1mm per day
Explanation:Peripheral nerves are nerves that lie outside the brain and spinal cord. Peripheral nerves readily regenerate, while central nervous system axonal injury does not spontaneously regenerate. If there is damage to the axons of peripheral nerves, the nerves will regenerate at a slow rate of 1 mm per day. The slow regeneration process may lead to muscle atrophy before regeneration is complete. Each peripheral nerve has a single cell body that supplies nutrients to the growing nerve fibre. The cell body does not undergo mitosis; only the axon is regenerated.Schwann cells of the peripheral nervous system provide support for this process, while the analogous oligodendrocytes of the central nervous system do not. Schwann cells themselves do not cause regeneration. Schwann cells provide myelin for myelinated fibres and surround non-myelinated fibres with their cytoplasm. If an axon is completely severed, as in the case of amputation, the axonal fibres regenerating from the cell body may never find their original route back to the muscle. Instead, they may form a traumatic neuroma, a painful collection of nerve fibres and myelin.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 6
Correct
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Which of the following laboratory findings are indicative of von Willebrand disease (VWD):
Your Answer: Prolonged APTT
Explanation:Laboratory results often show that:PFA-100 test results are abnormal.Low levels of factor VIII (if a factor VIII/VWF binding assay is conducted)APTT is Prolonged (or normal)PT is normalVWF values are low.Defective Platelet aggregationThe platelet count is normal.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 7
Correct
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Regarding Escherichia coli, which of the following statements is INCORRECT:
Your Answer: It is a predominant member of the normal flora of the skin.
Explanation:Escherichia coli is a Gram-negative bacilli that is an important member of the intestinal flora. It is the most common cause of UTI in adults (about 70 – 95% of cases), followed by Staphylococcus saprophyticus (about 5 – 10% of cases), and an important cause of neonatal meningitis. E. coli O157 strain is implicated in the development of dysentery associated with haemolytic uraemic syndrome characterised by haemolytic anaemia, thrombocytopenia and acute renal failure.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 8
Correct
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Regarding acute idiopathic thrombocytopaenic purpura (ITP), which of the following statements is CORRECT:
Your Answer: Over 80% of children recover without treatment.
Explanation:Acute ITP is most common in children. In approximately 75% of cases, the episode follows vaccination or infection such as chicken pox or glandular fever. Most cases are caused by non-specific immune complex attachment to platelets. Acute ITP usually has a very sudden onset and the symptoms usually disappear in less than 6 months (often within a few weeks). It is usually a self-limiting condition and over 80% of children recover without treatment; in 5 – 10% of cases a chronic form of the disease develops.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 9
Incorrect
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You examine a resuscitated patient who has been diagnosed with ventricular tachycardia. The patient's hemodynamics are normal. You intended to prescribe amiodarone to him, but you can't because he has a contraindication.In these circumstances, which of the following is a contraindication to using amiodarone?
Your Answer: Long QT syndrome
Correct Answer: Sinus node disease
Explanation:Amiodarone is an anti-arrhythmic medication that can be used to treat both ventricular and atrial arrhythmias.The use of amiodarone is contraindicated in the following situations:Conduction disturbances that are severe (unless pacemaker fitted)Sinus node disease is a condition that affects the lymph nodes in (unless pacemaker fitted)Sensitivity to iodineBlockage of the Sino-atrial heart valve (except in cardiac arrest)Bradycardia in the sinuses (except in cardiac arrest)Thyroid disorders
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 10
Correct
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Which of the following is NOT an advantage of a cohort study used to investigate the relationship between exposure to a risk factor and a future outcome:
Your Answer: Particularly suitable for rare diseases
Explanation:Advantages: ideal for studying associations between an exposure and an outcome when the exposure is uncommon, the time sequence of events can be assessed, they can provide information on a wide range of disease outcomes, the absolute and relative risk of disease can be measured directly, they can give a direct estimation of disease incidence ratesDisadvantages: costly and can take long periods of time if the outcome is delayed, subject to subject-selection and loss to follow-up bias, large sample size required for rare outcome of interest so it is not useful for rare diseases, prone to confounding
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This question is part of the following fields:
- Evidence Based Medicine
- Study Methodology
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Question 11
Correct
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A 66-year-old male presents to his family physician with the complaint of increasing fatigue and lethargy, along with itching, especially after a hot bath. He also complains of increased sweating and dizziness. On examination, he has a plethoric appearance. Abdominal examination shows the presence of splenomegaly. A basic panel of blood tests is ordered in which her Hb comes out to be 17 g/dL. Which one of the following treatment options will be most suitable in this case?
Your Answer: Venesection
Explanation:The clinical and laboratory findings, in this case, support a diagnosis of polycythaemia vera. A plethoric appearance, lethargy, splenomegaly and itching are common in this disease. Patients may also have gouty arthritis, Budd-Chiari syndrome, erythromelalgia, stroke, myocardial infarction or DVT. The average age for diagnosis of Polycythaemia Vera is 65-74 years. It is a haematological malignancy in which there is overproduction of all three cell lines. Venesection is the treatment of choice as it would cause a decrease in the number of red blood cells within the body.Erythropoietin is given in patients with chronic renal failure as they lack this hormone. Administration of erythropoietin in such patients causes stimulation of the bone marrow to produce red blood cells. Desferrioxamine is a chelating agent for iron and is given to patients with iron overload due to repeated blood transfusions, e.g. in thalassemia patients.Penicillamine is a chelating agent for Copper, given as treatment in Wilson’s disease.
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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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A 60-year-old female presents with fatigue, easy bruising and repeated chest and skin infections for five months. She also complains about several episodes of nosebleeds over the last few days without any history of trauma. Her complete blood count shows the following results: Hb 9 g/dlTotal leukocyte count: 2.5x10^9/L, 1100 neutrophils/ųLMCV 100platelet count of 90,000/ųL. Which one of the following conditions does this patient most likely have?
Your Answer: Myelodysplastic syndrome
Explanation:Myelodysplastic syndromes are a group of clonal haematopoietic disorders which are characterised by anaemia, leukopenia and thrombocytopenia. Patients will complain of fatigue, symptoms of thrombocytopenia such as nosebleeds and easy bleeding and a history of repeated infections due to low white blood cells (especially Neutrophils). In Chronic lymphocytic leukaemia production of hematopoietic cells goes on for a longer time. Folate and B12 deficiency would result in hypersegmented neutrophils and a raised MCV. Iron deficiency anaemia would not cause neutropenia or thrombocytopenia.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 13
Correct
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A 39-year-old woman is feeling unwell one week after a parathyroid surgery.Which of the following stimulates release of parathyroid hormone (PTH)?
Your Answer: Increased plasma phosphate concentration
Explanation:PTH is synthesised and released from the chief cells of the four parathyroid glands located behind the thyroid gland.It is a polypeptide containing 84 amino acids and it controls free calcium in the body.The following stimuli causes release of PTH:Increased plasma phosphate concentrationDecreased plasma calcium concentrationPTH release is inhibited by:Normal or 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 14
Incorrect
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Which of the following medications may lessen warfarin's anticoagulant effect:
Your Answer: Metronidazole
Correct Answer: Phenytoin
Explanation:Phenytoin will decrease the level or effect of warfarin by affecting hepatic/intestinal enzyme CYP3A4 metabolism.Metronidazole will increase the level or effect of warfarin by affecting hepatic enzyme CYP2C9/10 metabolism.NSAIDs, when given with Warfarin, increase anticoagulation.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 15
Correct
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You are reviewing a patient complaining of loss of vision. Previous images shows a lesion at the optic chiasm. What type of visual field defect are you most likely to see in a lesion at the optic chiasm:
Your Answer: Bitemporal hemianopia
Explanation:A lesion at the optic chiasm will result in a bitemporal hemianopia.A lesion of the optic nerve will result in ipsilateral monocular visual loss.A lesion of the optic tract will result in a contralateral homonymous hemianopia.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 16
Incorrect
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Regarding bile, which of the following statements is INCORRECT:
Your Answer: The bile acid-independent fraction of bile is made at the time it is required.
Correct Answer: The sphincter of Oddi contracts to force bile from the gallbladder into the duodenum.
Explanation:Bile is secreted by hepatocytes. It is isotonic and resembles plasma ionically. This fraction of bile is called the bile acid-dependent fraction. As it passes along the bile duct, the bile is modified by epithelial cells lining the duct by the addition of water and bicarbonate ions; this fraction is called the bile acid-independent fraction. Overall, the liver can produce 500 – 1000 mL of bile per day. The bile is either discharged directly into the duodenum or stored in the gallbladder. The bile acid-independent fraction is made at the time it is required i.e. during digestion of chyme. The bile acid-dependent fraction is made when the bile salts are returned from the GI tract to the liver, and is then stored in the gallbladder until needed. The gallbladder not only stores bile but concentrates it by removing non-essential solutes and water, leaving bile acids and pigments, mainly by active transport of Na+into the intercellular spaces of the lining cells which, in turn, draws in water, HCO3-and Cl-from the bile and into the extracellular fluid. Within a few minutes of a meal, particularly when fatty foods have been consumed, the gallbladder contracts and releases bile into the bile duct. The sphincter of Oddi is relaxed, allowing the bile to pass into the duodenum through the ampulla of Vater.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 17
Correct
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A 29-year-old volunteer returns from a recent trip to the middle east with profuse watery diarrhoea. You make a diagnosis of cholera and organize a hospital admission for rehydration with intravenous fluids.What is the mechanism of action of cholera toxin?
Your Answer: ADP-ribosylation of the G regulatory protein
Explanation:Cholera is caused by Vibrio cholerae, a motile, Gram-negative, curved bacillus. It is transmitted through water and food (especially seafood) and is primarily a disease seen in developing countries where there is poor sanitation and lack of safe water supplies.The cholera toxin leads to stimulation of adenyl cyclase, ADP-ribosylation of the G regulatory protein, inactivation of GTPase leading to active outpouring of NaCl. The cholera toxin consists of an A (the toxin) and B subunit. The B subunit attaches to the gut mucosa and presents the A subunit to the cell. The toxin stimulates adenyl cyclase by irreversible ADP-ribosylation of the GTP binding domain of adenyl cyclase leading to the opening of chloride channels resulting in an outpouring of NaCl and water into the lumen of the gut and causing secretory diarrhoea.Incubation period is between 2 and 5 days, but can be as short as just a few hours.
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 18
Correct
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A 78-year-old man develops renal impairment and hearing loss after inpatient management for sepsis.Which of these antibiotics is most likely to have been used?
Your Answer: Gentamicin
Explanation:Gentamicin, an aminoglycoside antibiotic, acts by binding to the 30S subunit of the bacterial ribosome inhibiting the binding of aminoacyl-tRNA, and thus prevents initiation of protein synthesis.Two of its most notable side effects are reversible nephrotoxicity(caused by the inhibition of protein synthesis in renal cells, which causes acute tubular necrosis) and hearing loss (caused by damage to the vestibular apparatus of the inner ear). Both side effects are dose-related and occur commonly in the elderly.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 19
Incorrect
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Cardiac myocytes contract by excitation-contraction coupling, very much like skeletal myocytes. On the other hand, calcium-induced calcium release (CICR) is a mechanism that is unique to Cardiac myocytes. The influx of calcium ions (Ca 2+) into the cell causes a 'calcium spark,' which causes more ions to be released into the cytoplasm.In CICR, which membrane protein in the sarcoplasmic reticulum is involved?Â
Your Answer: Ligand-gated calcium channel
Correct Answer: Ryanodine receptor
Explanation:Cardiac myocytes contract by excitation-contraction coupling, just like skeletal myocytes. Heart myocytes, on the other hand, utilise a calcium-induced calcium release mechanism that is unique to cardiac muscle (CICR). The influx of calcium ions (Ca2+) into the cell causes a ‘calcium spark,’ which causes more ions to be released into the cytoplasm.An influx of sodium ions induces an initial depolarisation, much as it does in skeletal muscle; however, in cardiac muscle, the inflow of Ca2+ sustains the depolarisation, allowing it to remain longer. Due to potassium ion (K+) inflow, CICR causes a plateau phase in which the cells remain depolarized for a short time before repolarizing. Skeletal muscle, on the other hand, repolarizes almost instantly.The release of Ca2+ from the sarcoplasmic reticulum is required for calcium-induced calcium release (CICR). This is mostly accomplished by ryanodine receptors (RyR) on the sarcoplasmic reticulum membrane; Ca2+ binds to RyR, causing additional Ca2+ to be released.
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 20
Correct
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A 22-year-old woman comes in with an asthmatic flare. Salbutamol is her only regular medication.What is the dosage per inhalation of a standard metered dose salbutamol inhaler?
Your Answer: 100 micrograms
Explanation:The dose of a conventional metered dose inhaler is 100 micrograms per metered inhalation.
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This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 21
Incorrect
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A 29-year-old woman with anaphylactic reaction to peanuts, had to use her EpiPen on the way to hospital. What percentage of patients with anaphylactic reaction suffer a biphasic response?.
Your Answer: 50%
Correct Answer: 20%
Explanation:About 20% of patients that suffer an anaphylactic reaction suffer a biphasic response 4-6 hours after the initial response (sometimes up to 72 hours after).
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 22
Correct
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The most important nerves for inversion of the foot are:
Your Answer: Tibial and deep fibular nerve
Explanation:Inversion of the foot is achieved by the tibialis anterior which is innervated by the deep fibular nerves, and the tibialis posterior muscles which is innervated by the tibial nerve respectively.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 23
Correct
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In the emergency room, a 28-year-old woman complains of wobbly and slurred speech, is unable to do the heel-shin test, and has nystagmus. The following signs are most likely related to damage to which of the following areas:
Your Answer: Cerebellum
Explanation:Cerebellar injury causes delayed and disorganized motions. When walking, people with cerebellar abnormalities sway and stagger. Damage to the cerebellum can cause asynergia, the inability to judge distance and when to stop, dysmetria, the inability to perform rapid alternating movements or adiadochokinesia, movement tremors, staggering, wide-based walking or ataxic gait, a proclivity to fall, weak muscles or hypotonia, slurred speech or ataxic dysarthria, and abnormal eye movements or nystagmus.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 24
Correct
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About what percentage of patients with hepatitis A develop chronic infection:
Your Answer: None
Explanation:Chronic hepatitis and carrier state does not occur in hepatitis A infection and complete immunity is attained after infection.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 25
Incorrect
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A 26-year-old athlete presents with buttock pain after tearing his gluteus maximus muscle.Which of the following is NOT an action of the gluteus maximus muscle? Select ONE answer only.
Your Answer: Raising the trunk from a flexed position
Correct Answer: Hip abduction
Explanation:Gluteus maximus is the main extensor muscle of the hip and assists with lateral rotation of the thigh at the hip joint. It also acts as a hip adductor, steadies the thigh, and assists in raising the trunk from a flexed position.Gluteus maximus is innervated by the inferior gluteal nerve.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 26
Incorrect
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A 2-day-old male is referred to a tertiary care hospital by the community midwife after a home visit due to jaundice and dyspnoea. After history and examination, the relevant blood work is performed, and the baby is found to have conjugated hyperbilirubinemia. The paediatric team suspects a hepatic origin for jaundice based on the findings. Which one of the following aetiologies is the most likely cause of jaundice in this case?
Your Answer: Biliary atresia
Correct Answer: Alpha 1-antitrypsin deficiency
Explanation:The presence of dyspnoea makes alpha-1 antitrypsin deficiency the more likely diagnosis as biliary atresia does not cause respiratory symptoms. Deficiency of the enzyme alpha-1 antitrypsin causes uninhibited elastase activity and a decrease in elastic tissue. This causes liver cirrhosis leading to an elevation of conjugated bilirubin and emphysema in the lungs.Rhesus disease, hereditary spherocytosis and breast milk jaundice cause an elevation of unconjugated bilirubin thus ruling it out in this case. Breast milk jaundice occurs due to an inability of the newborn to metabolize the proteins in breast milk. Rhesus disease occurs when an Rh negative mother gives birth to an Rh positive baby. The jaundice would have been accompanied by anaemia and oedema. Hereditary spherocytosis occurs due to extravascular haemolysis as defective RBCs are removed by the spleen. The patient would present with jaundice, splenomegaly and possibly an aplastic crisis (if Parvovirus B19 infection).
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 27
Correct
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A patient presents with severe vomiting. They take a maintenance dose of 12.5 mg of prednisolone daily for their COPD. They are unable to swallow or keep down tablets at present, and you plan on converting them to IV hydrocortisone.What dose of hydrocortisone is equivalent to this dose of prednisolone? Select ONE answer only.
Your Answer: 50 mg
Explanation:Prednisolone is four times more potent than hydrocortisone, and therefore, a dose of 12.5 mg would be equivalent to 50 mg of hydrocortisone.The following table summarises the relative potency of the main corticosteroids compared with hydrocortisone:CorticosteroidPotency relative to hydrocortisonePrednisolone4 times more potentTriamcinolone5 times more potentMethylprednisolone5 times more potentDexamethasone25 times more potent
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This question is part of the following fields:
- Endocrine Pharmacology
- Pharmacology
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Question 28
Correct
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Which of the following organelles form lysosomes?
Your Answer: The Golgi apparatus
Explanation:Lysosomes are formed by the Golgi apparatus or the endoplasmic reticulum. Lysosome releases its enzymes and digests the cell when the cell dies.
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 29
Correct
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Parathyroid hormone is released by which of the following:
Your Answer: Chief cells of the parathyroid gland
Explanation:Parathyroid hormone (PTH) is a peptide hormone synthesised by the chief cells of the parathyroid glands, located immediately behind the thyroid gland. PTH is primarily released in response to decreasing plasma [Ca2+] concentration. PTH acts to increase plasma calcium levels and decrease plasma phosphate levels.Parathyroid hormone (PTH) acts to increase calcium reabsorption in the distal tubule of the nephron (by activating Ca2+entry channels in the apical membrane and the Ca2+ATPase pump in the basolateral membrane) and increase phosphate excretion by inhibiting reabsorption in the proximal tubule of the nephron.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 30
Correct
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Damage to this nerve affects the flexor digitorum longus.
Your Answer: Tibial nerve
Explanation:Like all muscles in the deep posterior compartment of the leg, flexor digitorum longus muscle is innervated by branches of the tibial nerve (root value L5, S1 and S2) which is a branch of sciatic nerve.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 31
Incorrect
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A 64-year-old man presents with an acute episode of gout. He has a history of chronic heart failure and hypertension. His current medications include ramipril and furosemide.Which of the following statements regarding the treatment of gout is true? Select ONE answer only.
Your Answer: Corticosteroids should be avoided in acute gout
Correct Answer: Colchicine has a role in prophylactic treatment
Explanation:In the absence of any contra-indications, high-dose NSAIDs are the first-line treatment for acute gout. Naproxen 750 mg as a stat dose followed by 250 mg TDS is a commonly used and effective regime.Aspirin should not be used in gout as it reduces the urinary clearance of urate and interferes with the action of uricosuric agents. Naproxen, Diclofenac or Indomethacin are more appropriate choices.Allopurinol is used prophylactically, preventing future attacks by reducing serum uric acid levels. It should not be started in the acute phase as it increases the severity and duration of symptoms.Colchicine acts on the neutrophils, binding to tubulin to prevent neutrophil migration into the joint. It is as effective as NSAIDs in relieving acute attacks. It also has a role in prophylactic treatment if Allopurinol is not tolerated.NSAIDs are contra-indicated in heart failure as they can cause fluid retention and congestive cardiac failure. Colchicine is the preferred treatment in patients with heart failure or those who are intolerant of NSAIDs.
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This question is part of the following fields:
- Musculoskeletal Pharmacology
- Pharmacology
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Question 32
Correct
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On her most recent blood tests, a 55 year-old female with a history of hypertension was discovered to be hypokalaemic. She  is diagnosed with primary hyperaldosteronism.Which of the following is a direct action of aldosterone?
Your Answer: Secretion of H + into the distal convoluted tubule
Explanation:Aldosterone is a steroid hormone produced in the adrenal cortex’s zona glomerulosa. It is the most important mineralocorticoid hormone in the control of blood pressure. It does so primarily by promoting the synthesis of Na+/K+ATPases and the insertion of more Na+/K+ATPases into the basolateral membrane of the nephron’s distal tubules and collecting ducts, as well as stimulating apical sodium and potassium channel activity, resulting in increased sodium reabsorption and potassium secretion. This results in sodium conservation, potassium secretion, water retention, and a rise in blood volume and blood pressure.Aldosterone is produced in response to the following stimuli:Angiotensin II levels have risen.Potassium levels have increased.ACTH levels have risen.Aldosterone’s principal actions are as follows:Na+ reabsorption from the convoluted tubule’s distal endWater resorption from the distal convoluted tubule (followed by Na+)Cl is reabsorbed from the distal convoluted tubule.K+ secretion into the convoluted distal tubule’s H+ secretion into the convoluted distal tubule’sÂ
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 33
Correct
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A newborn baby is born by vaginal delivery to a mother who has a Chlamydia infection and who is started on treatment after the delivery. The neonate subsequently develops an infection also.Which one of these is the most common neonatal manifestation of Chlamydia trachomatis infection?
Your Answer: Conjunctivitis
Explanation:Conjunctivitis is the most common neonatal manifestation of Chlamydia trachomatis infection. The second commonest neonatal manifestation is pneumoniaOphthalmia neonatorum refers to any conjunctivitis in the newborn period, irrespective of causative organism. Presently, chlamydia is the single most common cause, accounting for up to 40% of cases. Ophthalmia neonatorum caused by chlamydia typically presents 5 to 14 days after birth with unilateral or bilateral watery discharge that progressively becomes more copious and purulent. There is no associated risk of ulceration and perforation, and the eyes are less inflamed.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 34
Correct
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Regarding antimuscarinic antispasmodics, which of the following statements is CORRECT:
Your Answer: They are contraindicated in paralytic ileus.
Explanation:Antimuscarinics are contraindicated in paralytic ileus. Antimuscarinics reduce intestinal motility by blocking muscarinic acetylcholine receptors and relaxing smooth muscle. Hyoscine butylbromide is advocated as a gastrointestinal antispasmodic, but it is poorly absorbed and thus has limited clinical utility. Antimuscarinics cause a reduction in bronchial secretions (they can be used to this effect in palliative patients). Antispasmodics are occasionally of value in treating abdominal cramp associated with diarrhoea but they should not be used for primary treatment. Antispasmodics should be avoided in young children with gastroenteritis because they are rarely effective and have troublesome side effects.
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This question is part of the following fields:
- Gastrointestinal
- Pharmacology
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Question 35
Correct
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Regarding the renin-angiotensin-aldosterone system (RAAS), which of the following statements is CORRECT:
Your Answer: Angiotensin II has a predominant vasoconstrictor effect on the efferent arteriole.
Explanation:Angiotensin II constricts both the afferent and efferent arterioles, but preferentially increases efferent resistance. The net effect of the more prominent increase in efferent tone is that the intraglomerular pressure is stable or increased, thereby tending to maintain or even raise the GFR. Renin is produced by granular cells of the juxtaglomerular apparatus. Renin cleaves plasma angiotensinogen (produced in the liver) into angiotensin I. Angiotensin I is converted by angiotensin-converting enzyme (ACE) on pulmonary endothelial cells to angiotensin II. Angiotensin II acts to potentiate sympathetic activity (positive feedback).
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This question is part of the following fields:
- Physiology
- Renal
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Question 36
Incorrect
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Stimulation of J receptors located on alveolar and bronchial walls results in all of the following EXCEPT for:
Your Answer: Relaxation of skeletal muscle
Correct Answer: Tachycardia
Explanation:Juxtapulmonary or ‘J’ receptors are located on alveolar and bronchial walls close to the capillaries. Their afferents are small unmyelinated C-fibres or myelinated nerves in the vagus nerve. Activation causes depression of somatic and visceral activity by producing apnoea or rapid shallow breathing, a fall in heart rate and blood pressure, laryngeal constriction and relaxation of skeletal muscles via spinal neurones. J receptors are stimulated by increased alveolar wall fluid, pulmonary congestion and oedema, microembolism and inflammatory mediators. J receptors are thought to be involved in the sensation of dyspnoea in lung disease.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 37
Correct
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What is the mechanism of action of penicillin antibiotics:
Your Answer: Inhibition of bacterial cell wall synthesis
Explanation:Penicillins and the other ß-lactam antibiotics are bactericidal. They produce their antimicrobial action by preventing cross-linkage between the linear peptidoglycan polymer chains that make up the bacterial cell wall. They, therefore, inhibit cell wall synthesis.The integrity of the ß-lactam ring is essential for antimicrobial activity. Many bacteria (including most Staphylococci) are resistant to benzylpenicillin and phenoxymethylpenicillin because they produce enzymes (penicillinases, ß-lactamases) that open the ß-lactam ring.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 38
Correct
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You are going to prescribe a NSAID to a 50-year-old male patient for his back pain. Which of the following NSAIDs is least likely to cause gastrointestinal side effects:
Your Answer: Ibuprofen
Explanation:NSAIDs are associated with serious gastrointestinal irritation and drug-induced ulcers. Among the NSAIDs included in the choices, ibuprofen has the lowest risk. Piroxicam, ketoprofen, and ketorolac trometamol are associated with the highest risk of serious upper gastrointestinal side effects. Indomethacin, diclofenac, and naproxen are associated with an intermediate risk of serious upper gastrointestinal side effects.
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This question is part of the following fields:
- Musculoskeletal
- Pharmacology
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Question 39
Correct
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After collapsing at home, a 75-year-old man is transported in an ambulance. He is now awake, but he is experiencing palpitations and chest pain. He is transported to resuscitation and placed on a cardiac monitor, which indicates that he is in VT. An amiodarone infusion is set up.Which of the following statements about amiodarone side effects is correct?
Your Answer: It can cause jaundice
Explanation:Amiodarone has a lot of potential toxic side effects, so it’s important to get a full clinical evaluation before starting treatment with it.The following are some of the most common amiodarone side effects:ArrhythmiasCorneal microdepositsHepatic disordersHyperthyroidismHypothyroidismHepatic disorders and jaundiceNauseaPeripheral neuropathyRespiratory disorders (including lung fibrosis)Sleep disturbanceSkin reactionsQT prolongationAmiodarone can cause optic neuritis, which is a very rare side effect. If this happens, the amiodarone should be stopped right away because it poses a risk of blindness.Most people who take amiodarone develop corneal microdeposits, which go away once the medication is stopped and rarely cause vision problems.Amiodarone has a chemical structure that is similar to that of thyroxine and can bind to the nuclear thyroid receptor. It can cause both hypothyroidism and hyperthyroidism, though hypothyroidism is far more common, with 5-10% of patients suffering from it.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 40
Correct
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Which of the following is a primary action of calcitonin:
Your Answer: Decreased bone resorption through inhibition of osteoclast activity
Explanation:Calcitonin is a 32 amino acid polypeptide that is primarily synthesised and released by the parafollicular cells (C-cells) of the thyroid gland in response to rising or high levels of plasma Ca2+ions. Its primary role is to reduce the plasma calcium concentration, therefore opposing the effects of parathyroid hormone.Secretion of calcitonin is stimulated by:- Increased plasma calcium concentration- Gastrin- Pentagastrin- The main actions of calcitonin are:- Inhibition of osteoclastic activity (decreasing calcium and phosphate resorption from bone)- Stimulation of osteoblastic activity- Decreases renal calcium reabsorption- Decreases renal phosphate reabsorption
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 41
Correct
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An elderly man presents with bilateral lower facial swelling around the mandible and upper neck. A CT scan of his neck was performed and the results were conclusive with Ludwig's angina.Which of the following spaces is most likely affected based on the case presented?
Your Answer: Submandibular space
Explanation:Ludwig’s angina is life-threatening cellulitis of the soft tissue involving the floor of the mouth and neck. It involves three compartments of the floor of the mouth: the sublingual, submental, and submandibular.Ludwig’s angina usually originates as a dental infection of the second or third mandibular molars. The infection begins in the subgingival pocket and spreads to the musculature of the floor of the mouth. It progresses below the mylohyoid line, indicating that it has moved to the sublingual space. As the roots of the second and third mandibular molars lie below this line, infection of these teeth will predispose to Ludwig’s angina. The infection spreads lingually rather than buccally because the lingual aspect of the tooth socket is thinner. It initially spreads to the sublingual space and progresses to the submandibular space.The disease is usually polymicrobial, involving oral flora, both aerobes, and anaerobes. The most common organisms are Staphylococcus, Streptococcus, Peptostreptococcus, Fusobacterium, Bacteroides, and Actinomyces.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 42
Incorrect
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Eosinophils comprise what percentage of circulating white cells:
Your Answer: 0.2
Correct Answer: 1 - 3%
Explanation:Eosinophils comprise 1 – 3% of circulating white cells. Eosinophils are similar to neutrophils, except that the cytoplasmic granules are coarser and more deeply red staining, and there are rarely more than three nuclear lobes. They are less motile, but longer lived. They enter inflammatory exudates and have a special role in allergic responses, defence against parasites and removal of fibrin formed during inflammation. Thus they play a role in local immunity and tissue repair.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 43
Correct
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You proceed to administer lorazepam intravenously to a 21-year-old patient with status epilepticus. Which of the following best describes lorazepam's action?
Your Answer: Potentiates effect of GABA
Explanation:Lorazepam is a type of benzodiazepine. Benzodiazepines are gamma-aminobutyric acid (GABA) receptor agonists with sedative, hypnotic, anxiolytic, anticonvulsant, and muscle relaxant characteristics that promote inhibitory synaptic transmission across the central nervous system.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 44
Correct
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Which of the following is the site of secretion of intrinsic factor:
Your Answer: Stomach
Explanation:Intrinsic factor is essential for the absorption of the small amounts of vitamin B12 normally present in the diet from the terminal ileum. The parietal cells of the stomach produce intrinsic factor, and following a gastrectomy, the absorption of vitamin B12 will be markedly reduced, and a deficiency state will exist.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 45
Incorrect
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A patient is complaining of painless jaundice. His bilirubin levels are abnormally high.Which of the following statements about bile is correct?
Your Answer: Cholecystokinin expands the volume of bile
Correct Answer: Bile acids are amphipathic
Explanation:The liver produces bile on a constant basis, which is then stored and concentrated in the gallbladder. In a 24-hour period, around 400 to 800 mL of bile is generated.Bile is involved in the following processes:Fats are broken down into fatty acids.Waste products are eliminated.Cholesterol homeostasis is the balance of cholesterol in the body.The enteric hormones cholecystokinin and secretin are primarily responsible for bile secretion. When chyme from an unprocessed meal enters the small intestine, they are released, and they play the following function in bile secretion and flow:Cholecystokinin promotes gallbladder and common bile duct contractions, allowing bile to reach the intestine.Secretin enhances the secretion of bicarbonate and water by biliary duct cells, increasing the amount of bile and its flow into the gut.Bile acids have a hydrophobic and hydrophilic area, making them amphipathic. Bile acids’ amphipathic nature allows them to perform the following crucial functions:Emulsification of lipid aggregates increases the surface area of fat and makes it easier for lipases to digest it.Lipid solubilization and transport: solubilizes lipids by creating micelles, which are lipid clumps that float in water.
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This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 46
Correct
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Following a phone call from the microbiology consultant, you evaluate a patient who has been diagnosed with urinary sepsis. Following the results of the blood cultures, he recommends that you add gentamicin to the patient's antibiotic treatment.Gentamicin produces its pharmacological effect by binding to which of the following?Â
Your Answer: The 30S subunit of the bacterial ribosome
Explanation:Antibiotics with aminoglycosides, such as gentamicin, bind to the 30S subunit of the bacterial ribosome and prevent aminoacyl-tRNA from binding, preventing protein synthesis.They also cause mRNA misreading, resulting in the production of non-functional proteins. This last mechanism is unique to aminoglycosides, and it may explain why they are bactericidal rather than bacteriostatic, as other protein synthesis inhibitors are.Patients with myasthenia gravis should avoid aminoglycosides since they can disrupt neuromuscular transmission. They cross the placenta and are linked to poisoning of the 8th cranial nerve in the foetus, as well as permanent bilateral deafness.It is possible that they will cause deafness, although this is not a contraindication. In individuals with renal impairment, serum aminoglycoside concentrations should be closely monitored, but this is still not considered a contraindication.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 47
Correct
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Regarding pressures and airflow during the normal breathing cycle, which of the following statements is INCORRECT:
Your Answer: Negative intrapleural pressure causes dynamic compression of the airways.
Explanation:Dynamic compression occurs during forced expiration, when as the expiratory muscles contract, all the structures within the lungs, including the airways, are compressed by the positive intrapleural pressure. Consequently the smaller airways collapse before the alveoli empty completely and some air remains within the lungs (the residual volume).
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 48
Correct
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Which family of receptors does the glucagon receptor belong?
Your Answer: G-protein coupled receptors
Explanation:Glucagon binds to class B G-protein coupled receptors and activates adenylate cyclase, increasing cAMP intracellularly. This activates protein kinase A. Protein kinase A phosphorylates and activates important enzymes in target cells.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 49
Incorrect
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A 47-year old male comes to the out-patient department for a painful, right-sided groin mass. Medical history reveals a previous appendectomy 10 years prior. On physical examination, the mass can be reduced superiorly. Also, the mass extends to the scrotum. The initial diagnosis is a hernia.Among the types of hernia, which is the most likely diagnosis of the case above?
Your Answer: Incisional hernia
Correct Answer: Indirect inguinal hernia
Explanation:Inguinal hernias can present with an array of different symptoms. Most patients present with a bulge in the groin area, or pain in the groin. Some will describe the pain or bulge that gets worse with physical activity or coughing. Symptoms may include a burning or pinching sensation in the groin. These sensations can radiate into the scrotum or down the leg. It is important to perform a thorough physical and history to rule out other causes of groin pain. At times an inguinal hernia can present with severe pain or obstructive symptoms caused by incarceration or strangulation of the hernia sac contents. A proper physical exam is essential in the diagnosis of an inguinal hernia. Physical examination is the best way to diagnose a hernia. The exam is best performed with the patient standing. Visual inspection of the inguinal area is conducted first to rule out obvious bulges or asymmetry in groin or scrotum. Next, the examiner palpates over the groin and scrotum to detect the presence of a hernia. The palpation of the inguinal canal is completed last. The examiner palpates through the scrotum and towards the external inguinal ring. The patient is then instructed to cough or perform a Valsalva manoeuvre. If a hernia is present, the examiner will be able to palpate a bulge that moves in and out as the patient increases intra abdominal pressure through coughing or Valsalva.Groin hernias are categorized into 2 main categories: inguinal and femoral.Inguinal hernias are further subdivided into direct and indirect. An indirect hernia occurs when abdominal contents protrude through the internal inguinal ring and into the inguinal canal. This occurs lateral to the inferior epigastric vessels. The hernia contents may extend into the scrotum, and can be reduced superiorly then superolaterally. A direct inguinal hernia is protrusion of abdominal contents through the transversalis fascia within Hesselbach’s triangle. The borders of Hesselbach’s triangle are the inferior epigastric vessels superolaterally, the rectus sheath medially, and inguinal ligament inferiorly.A femoral hernia is a protrusion into the femoral ring. The borders of the femoral ring are the femoral vein laterally, Cooper’s ligament posteriorly, the iliopubic tract/inguinal ligament anteriorly and lacunar ligament medially.
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This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 50
Incorrect
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What type of visual field defect are you most likely to see in a lesion of the parietal optic radiation:
Your Answer: Contralateral homonymous superior quadrantanopia
Correct Answer: Contralateral homonymous inferior quadrantanopia
Explanation:A lesion of the parietal optic radiation will result in a contralateral homonymous inferior quadrantanopia.A lesion of the temporal optic radiation will result in a contralateral homonymous superior quadrantanopia.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 51
Correct
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A 43 year old lady suffering with idiopathic thrombocytopenic purpura has a splenectomy. She is advised to get the Pneumococcal vaccine booster every 5 - 10 years as Streptococcus pneumoniae has which of the following properties that make her prone to infection to this organism?
Your Answer: It is encapsulated
Explanation:There is a lifelong susceptibility to increased risk of infection from a variety of organisms in patients with hyposplenism, especially in children under 5 years and those with sickle cell anaemia. Patients are most susceptible is to the encapsulated bacteria Streptococcus pneumoniae, Haemophilus influenzae type B and Neisseria meningitidis. Streptococcus pneumoniae is particular concerning as it can cause rapid and fulminant disease, which can be fatal. Malaria and animal bites that become infected also tend to be more severe.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 52
Correct
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A 36 year old man who is overweight with a history of gout, presents to emergency room with an acutely painful big toe which is red, hot and swollen. However, he is apyrexic and otherwise systemically well. He has been diagnosed with acute gout. The most appropriate first line treatment for him is which of the following?
Your Answer: NSAIDs
Explanation:The first line treatment for acute gout includes NSAIDs like diclofenac, indomethacin or naproxen. In patients in whom NSAIDs are contraindicated, not tolerated or ineffective, colchicine is an alternative. In those who cannot tolerate or who are resistant to NSAIDs and colchicine, oral or parenteral corticosteroids are an effective alternative. In acute monoarticular gout, intra-articular injection of a corticosteroid can be used occasionally. In acute gout. allopurinol is not used in the actual treatment, but its use should be continued during an acute attack if the patient is already established on long term therapy.
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This question is part of the following fields:
- Musculoskeletal
- Pharmacology
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Question 53
Incorrect
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A 22 year old male has been stabbed and is brought to the ED with a stab wound to his upper limb. On examination, the patient is unable to flex the distal interphalangeal joints of the ring and little finger. However, the proximal interphalangeal joint is intact. The most likely affected nerve is which of the following, and at which level is this occurring?
Your Answer: Ulnar nerve at wrist
Correct Answer: Ulnar nerve at elbow
Explanation:The medial half of the flexor digitorum profundus is innervated by the ulnar nerve. Paralysis of this muscle results in loss of flexion at the distal interphalangeal joint of the ring and little finger. Flexion at the proximal interphalangeal joint is preserved as this is a function of the flexor digitorum superficialis which is innervated by the median nerve. The ulnar nerve is not correct as ulnar nerve injury at the wrist would not affect the long flexors, and the injury must have been more proximal.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 54
Correct
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On which of the following is preload primarily dependent?
Your Answer: End-diastolic volume
Explanation:Preload refers to the initial stretching of the cardiac myocytes before contraction. It is therefore related to muscle sarcomere length. The sarcomere length cannot be determined in the intact heart, and so, other indices of preload are used, like ventricular end-diastolic volume or pressure. The end-diastolic pressure and volume of the ventricles increase when venous return to the heart is increased, and this stretches the sarcomeres, which increase their preload.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 55
Incorrect
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An elderly man with chronic heart and lung disease develops Legionnaires' disease. Which of the following clinical features is NOT typical of Legionnaires' disease:
Your Answer: Nausea, vomiting and diarrhoea
Correct Answer: Haemoptysis
Explanation:Legionella pneumophilais a Gram negative bacterium that is found in natural water supplies and in the soil, transmitted predominantly via inhalation of aerosols generated from contaminated water (direct person-to-person spread of infected patients does not occur). It is the cause of Legionnaires’ disease. Outbreaks of Legionnaires’ disease have been linked to poorly maintained air conditioning systems, whirlpool spas and hot tubs.The clinical features of the pneumonic form of Legionnaires’ disease include:Mild flu-like prodrome for 1-3 daysCough (usually non-productive and occurs in approximately 90%)Pleuritic chest painHaemoptysisHeadacheNausea, vomiting and diarrhoeaAnorexiaLegionella pneumophilainfections can be successfully treated with macrolide antibiotics, such as erythromycin, or quinolones, such as ciprofloxacin. Tetracyclines, such as doxycycline, can also be used.The syndrome of inappropriate antidiuretic hormone secretion (SIADH) can occur with Legionnaires’ disease and will result in hyponatraemia as is seen in this case.Legionella pneumophilainfections are resistant to amoxicillin but can be successfully treated with macrolide antibiotics, such as erythromycin, or quinolones, such as ciprofloxacin. Tetracyclines, such as doxycycline, can also be used. The majority of cases of Legionnaires’ disease are caused by Legionella pneumophila, however many other species of Legionella have been identified.Legionella longbeachae is another less commonly encountered species that has also been implicated in outbreaks. It is predominantly found in soil and potting compost, and has caused outbreaks of Pontiac fever, the non-respiratory and less severe variant of Legionnaires’ disease.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 56
Correct
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This anatomic part lies at the heart of the tooth.
Your Answer: The pulp cavity
Explanation:Within the central portion of the tooth lies the dental pulp. The pulp chamber provides mechanical support and functions as a barrier from external stimuli and the oral microbiome. The dental pulp is a unique tissue that is richly innervated and has an extensive microvascular network. Maintaining its vitality increases both the mechanical resistance of the tooth and the long-term survival. The junctional epithelium forms a band around the tooth at the base of the gingival sulcus, sealing off the periodontal tissues from the oral cavity.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 57
Incorrect
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Regarding likelihood ratios, which of the following statements is INCORRECT:
Your Answer: A test with a low negative likelihood ratio is good at increasing certainty about the absence of a disorder.
Correct Answer: Likelihood ratios, like predictive values, are affected by the prevalence of the disease in the population.
Explanation:A likelihood ratio is a measure of the diagnostic value of a test. Likelihood ratios show how many times more likely patients with a disease are to have a particular test result than patients without the disease. Likelihood ratios are more useful than predictive values because they are calculated from sensitivity and specificity and therefore remain constant even when the prevalence of the disorder changes.
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 58
Correct
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Regarding folate requirements, which of the following statements is CORRECT:
Your Answer: Dietary folate is found particularly in leafy green vegetables and liver.
Explanation:Megaloblastic anemia results from inhibition of DNA synthesis during red blood cell production. When DNA synthesis is impaired, the cell cycle cannot progress from the growth stage to the mitosis stage. This leads to continuing cell growth without division, which presents as macrocytosis, with an increase in mean corpuscular volume (MCV). The defect in red cell DNA synthesis is most often due to hypovitaminosis, specifically vitamin B12 deficiency or folate deficiency.Folate is an essential vitamin found in most foods, especially liver, green vegetables and yeast. The normal daily diet contains 200 – 250 μg, of which about 50% is absorbed. Daily adult requirements are about 100 μg. Absorption of folate is principally from the duodenum and jejunum. Stores of folate are normally only adequate for 4 months and so features of deficiency may be apparent after this time.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 59
Correct
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Contraction of the diaphragm results in which of the following effects:
Your Answer: Increased vertical dimension of the thorax
Explanation:Contraction of the diaphragm (as in inspiration) results in flattening (depression) of the diaphragm with an increase in vertical dimension of the thorax. This results in decreased intrathoracic pressure and increased intra-abdominal pressure.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 60
Correct
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A 62-year-old woman presents with a 3-month history of lethargy and tiredness. She states that she has also felt very itchy, particularly after a hot bath and that she is often dizzy and sweaty. On examination she appears plethoric and you note the presence of splenomegaly. Her blood tests today show that her haemoglobin level is 16.9 g/dl.What is the most likely diagnosis in this case? Select ONE answer only.
Your Answer: Polycythaemia vera
Explanation:Polycythaemia vera (PCV), which is also referred to as polycythaemia rubra vera, is a clonal haematological malignancy in which the bone marrow produces too many red blood cells. It may also result in the overproduction of white blood cells and platelets. It is most commonly seen in the elderly and the mean age at diagnosis is 65-74 years.Patients can be completely asymptomatic and it is often discovered as an incidental finding on a routine blood count. Approximately 1/3 of patients present with symptoms due to thrombosis, of these 3/4 have arterial thrombosis and 1/4 venous thrombosis. Features include stroke, myocardial infarction, deep vein thrombosis and pulmonary embolism.The other clinical features of PCV include:Plethoric appearanceLethargy and tirednessSplenomegaly (common)Pruritis (in 40% – particularly after exposure to hot water)Headaches, dizziness and sweating (in 30%)Gouty arthritis (in 20%)Budd-Chiari syndrome (in 5-10%)Erythromyalgia (in 18.5 g/dl in men, 16.5 g/dl in womenElevated red cell mass > 25% above mean normal predicted valuePresence of JAK2 mutationMinor criteria:Bone marrow biopsy showing hypercellularity with prominent erythroid, granulocytic and megakaryocytic proliferationSerum erythropoietin level below normal rangeEndogenous erythroid colony formation in vitroThe main aim of treatment is to normalize the full blood count and prevent complications such as thrombosis. Venesection is the treatment of choice but hydroxyurea can also be used to help control thrombocytosis.
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This question is part of the following fields:
- Haematology
- Pathology
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SESSION STATS - PERFORMANCE PER SPECIALTY
