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Question 1
Incorrect
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Diagnosis of HIV is predominantly made through which of the following:
Your Answer: Viral PCR
Correct Answer: Antibody detection
Explanation:Diagnosis of HIV is predominantly made through detection of HIV antibody and p24 antigen. Viral load (viral PCR) and CD4 count are used to monitor progression of disease.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 2
Incorrect
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Which of the following is a contraindication to the use of opioid analgesics:
Your Answer: Acute angle-closure glaucoma
Correct Answer: Raised intracranial pressure
Explanation:Opioids should be avoided in people who have: A risk of paralytic ileus (opioids reduce gastric motility)Acute respiratory depressionAn acute exacerbation of asthma (opioids can aggravate bronchoconstriction as a result of histamine release)Conditions associated with increased intracranial pressure including head injury (opioids can interfere with pupillary response making neurological assessment difficult and may cause retention of carbon dioxide aggravating the increased intracranial pressure)
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 3
Incorrect
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Regarding the management of gout, which of the following statements is CORRECT:
Your Answer: Ibuprofen is the NSAID of choice in treating acute gout.
Correct Answer: Allopurinol may cause an acute attack of gout when first started.
Explanation:Allopurinol is a treatment for the prevention of gout. The initiation of treatment may precipitate an acute attack, and should be covered with an NSAID or colchicine, continued for at least one month after the hyperuricaemia has been corrected. Colchicine is not indicated for long term prevention of gout. NSAIDs are first line for acute gout; colchicine is an alternative in whom NSAIDs are contraindicated, not tolerated or ineffective (including in people taking anticoagulants). Ibuprofen is not recommended for acute gout, given it has only weak anti-inflammatory properties; naproxen, diclofenac or indometacin are indicated instead.
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This question is part of the following fields:
- Musculoskeletal
- Pharmacology
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Question 4
Incorrect
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Following a bee sting, a 12-year old boy was transported to resus with symptoms and signs of an anaphylactic reaction. You decide to administer adrenaline IM stat.What is the recommended dose of intramuscular adrenaline?
Your Answer: 0.5 mL of 1:1000
Correct Answer: 0.3 mL of 1:1000
Explanation:Anaphylaxis is a type I hypersensitivity reaction that is severe and life-threatening. It is marked by the fast onset of life-threatening airway and/or circulatory issues, which are generally accompanied by skin and mucosal abnormalities. When an antigen attaches to specific IgE immunoglobulins on mast cells, degranulation and the release of inflammatory mediators takes place (e.g. histamine, prostaglandins, and leukotrienes).The most important medicine for treating anaphylactic responses is adrenaline. It decreases oedema and reverses peripheral vasodilation as an alpha-adrenergic receptor agonist. Its beta-adrenergic effects widen the bronchial airways, enhance the force of cardiac contraction, and inhibit the release of histamine and leukotriene. The first medicine to be given is adrenaline, and the IM route is optimal for most people.In anaphylaxis, age-related dosages of IM adrenaline are:150 mcg (0.15 mL of 1:1000) for a child under 6 years300 mcg (0.3 mL of 1:1000) for a child aged 6 to 12 years 500 mcg (0.5 mL of 1:1000) for children aged 12 and above 500 mcg for adults (0.5 mL of 1:1000)
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This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 5
Correct
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Regarding the power of a study, which of the following statements is INCORRECT:
Your Answer: The power of a study is not affected by data variability.
Explanation:A study should only be undertaken if the power is at least 80%; a study power set at 80% accepts a likelihood of 1 in 5 (20%) of missing a statistically significant difference where one exists.The determinants of power are:the sample size (the power increases with sample size)the variability of the observations (the power increases as the variability decreases)the effect size of interest (the power is greater for a larger expected effect size)and the significance level, α (the power is greater if the significance level is larger); therefore the probability of a type I error increases as the probability of a type II error decreases.
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 6
Incorrect
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A 35 year old man presents with a deep laceration to the proximal part of the forearm. On further assessment, the patient is unable to flex the metacarpophalangeal joints and interphalangeal joints of the index, middle finger and the thumb. The ring and little fingers are intact but there is weakness at the proximal interphalangeal joint.There is also loss of sensation over the lateral palm and the palmar surface of the lateral three and a half fingers. Which of these nerve(s) has most likely been affected?
Your Answer: Median and radial nerve
Correct Answer: Median nerve
Explanation:A median nerve injury affecting the extrinsic and intrinsic muscles of the hand will present with:Loss of sensation to the lateral palm and the lateral three and a half fingers.Weakness of flexion at the metacarpophalangeal joints of the index and middle finger. This is because of paralysis of the lateral two lumbricals. Weakness of flexion of the proximal interphalangeal joints of all four fingers due to paralysis of the flexor digitorum superficialisWeakness of flexion at the distal interphalangeal joints of the index and middle finger following paralysis of the lateral half of the flexor digitorum profundus.Weakness of thumb flexion, abduction and opposition due to paralysis of the flexor pollicis longus and thenar muscles
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 7
Correct
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A 56-year-old female visits her cardiologist complaining of a condition that has started since he started her on amiodarone for atrial arrhythmia. The cardiologist recognised that she is experiencing a side effect of amiodarone. Which one of the following conditions will this woman NOT have?
Your Answer: Xanthopsia
Explanation:Amiodarone is a class III potassium channel blocker used to treat multiple types of arrhythmias. Side effects include:1. pulmonary fibrosis2. blue discolouration of the skin3. phototoxicity4. corneal deposits5. hepatic necrosis6. thyroid dysfunction7. sleep disturbances8. peripheral neuropathy. Xanthopsia is a condition where the patient complains of seeing yellow lines and is seen in digoxin overdose.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 8
Correct
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Which of the following presentations is NOT consistent with the diagnosis of anaphylaxis following exposure to a known allergen:
Your Answer: Generalised urticaria and angioedema alone
Explanation:Anaphylaxis is characterised by sudden onset and rapidly developing, life-threatening airway, breathing and circulation problems associated with skin and/or mucosal changes. Reactions can vary greatly, from hypotension alone, to reactions with predominantly asthmatic features, to cardiac/respiratory arrest. Skin or mucosal changes may be absent or subtle in up to 20% of cases but skin or mucosal changes alone are not a sign of an anaphylactic reaction.
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 9
Correct
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Regarding threadworms, which of the following statements is CORRECT:
Your Answer: First line treatment of threadworms is with mebendazole.
Explanation:First line treatment of threadworms is with mebendazole, with treatment of the whole family, and a repeat treatment after 2 weeks. Threadworms live in the large bowel, but direct multiplication of worms does not occur here. Threadworms most commonly infect children, and may be symptomatic or cause pruritus ani.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 10
Incorrect
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A 23-year-old man is discovered to have an infection from Helicobacter pylori. Which of the following types of cancer is mostly associated with Helicobacter pylori infection?
Your Answer: Oesophageal cancer
Correct Answer: Gastric cancer
Explanation:H. pylori is recognized as a major cause of type B gastritis, a chronic condition formerly associated primarily with stress and chemical irritants. In addition, the strong association between long-term H. pylori infection and gastric cancer has raised more questions regarding the clinical significance of this organism. There is speculation that long-term H. pylori infection resulting in chronic gastritis is an important risk factor for gastric carcinoma resulting in H. pylori being classified as a carcinogen.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 11
Incorrect
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In the ventricular myocyte action potential, depolarisation occurs through the opening of:
Your Answer: Voltage-gated Ca 2+ channels
Correct Answer: Voltage-gated Na + channels
Explanation:An action potential (AP) is initiated when the myocyte is depolarised to a threshold potential of about -65 mV, as a result of transmission from an adjacent myocyte via gap junctions. Fast voltage-gated Na+channels are activated and a Na+influx depolarises the membrane rapidly to about +30 mV. This initial depolarisation is similar to that in nerve and skeletal muscle, and assists the transmission to the next myocyte.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 12
Correct
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Fenestrated capillaries are typically found where in the body:
Your Answer: Renal glomeruli
Explanation:Fenestrated capillaries, found in renal glomeruli, endocrine glands and intestinal villi, are more permeable than continuous capillaries with less tight junctions, and the endothelial cells are also punctured by pores which allow large amounts of fluids or metabolites to pass.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 13
Incorrect
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All of the following cause bronchoconstriction, EXCEPT for:
Your Answer: Reflex activation of parasympathetic nerves
Correct Answer: Adrenaline
Explanation:Factors causing bronchoconstriction:Via muscarinic receptorsParasympathetic stimulationStimulation of irritant receptorsInflammatory mediators e.g. histamine, prostaglandins, leukotrienesBeta-blockers
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 14
Correct
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All of the following statement are correct regarding endothelium derived nitric oxide except:
Your Answer: Nitric oxide production is inhibited by local mediators such as bradykinin, histamine and serotonin.
Explanation:Factors that elevate intracellular Ca2+ increase nitric oxide (NO) production by the endothelium included local mediators such as histamine and serotonin, bradykinin, and some neurotransmitters like substance P. NO production is also stimulated by increased flow (shear stress) and additionally activates prostacyclin synthesis. As a result of basal production of NO, there is continuous modulation of vascular resistance and as a result, there is increased production of nitric oxide acts which causes vasodilation. Platelet activation and thrombosis are inhibited by nitric oxide.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 15
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: Allopurinol is an effective treatment for 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 16
Correct
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A 7-year-old presented to a GP with a history of headache, neck stiffness and photophobia. On examination, HR is 122, BP is 87/42, RR is 28, SaO 2 is 95%, temperature is 39.4 o C. There is a recent non-blanching rash on legs and arms. The GP administered a dose of antibiotics before transferring child to the Emergency Department.Which of these is the most appropriate antibiotic to administer in this scenario from the choices available?
Your Answer: Give IM benzylpenicillin 600 mg
Explanation:Meningococcal septicaemia should be suspected in a child with a non-blanching rash especially in the presence of:An ill-looking childNeck stiffnessLesions larger than 2 mm in diameter (purpura)Capillary refill time of>3 secondsThe index child is very sick and shows signs of septic shock. In the prehospital setting, a single dose of benzylpenicillin should be given immediately. The correct dose for this childs age is IM benzylpenicillin 600 mg.The recommended doses of benzylpenicillin according to age are:Infants <1 year of age: IM or IV benzylpenicillin 300 mgChildren 1 to 9 years of age: IM or IV benzylpenicillin 600mgChildren and adults 10 years or older: IM or IV benzylpenicillin 1.2g
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 17
Correct
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Which of the following neurotransmitter and receptor combinations is present at the neuromuscular junction:
Your Answer: Acetylcholine acting at nicotinic receptors
Explanation:At the neuromuscular junction, acetylcholine is released from the prejunctional membrane which acts on cholinergic nicotinic receptors on the postjunctional membrane.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 18
Correct
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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 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 19
Incorrect
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Regarding fibrinolytics, which of the following statements is INCORRECT:
Your Answer: Tenecteplase has a longer half-life than alteplase allowing for bolus administration.
Correct Answer: Fibrinolytic drugs act as thrombolytics by directly degrading the fibrin mesh and so breaking up thrombi.
Explanation:Fibrinolytic drugs act as thrombolytics by activating plasminogen to form plasmin, which degrades fibrin and so breaks up thrombi.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 20
Incorrect
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A 79-year-old male had a humeral shaft fracture during a road traffic accident and is being followed up in a fracture clinic. He complains of inability to use the limb 6 months after the injury. X-rays of that arm shows non union of his fracture.All the following are responsible for this non-union EXCEPT?
Your Answer: Infection
Correct Answer: Osteoporosis
Explanation:An imbalance between bone resorption and formation is Osteoporosis. In normal bone, formation and resorption are roughly equal, and the density of bone matrix remains constant but there is more resorption in osteoporosis and the matrix density reduces and bones become weaker. Fractures are more likely to occur but healing is unaffected. Non-union of a fracture occurs when the two sides of a fracture fail to unite after 6 months. Causes include: infection, movement at the fracture site, avascular necrosis, tissue interposed between the fracture and gross misalignment.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 21
Correct
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A 52-year-old patient requires procedural sedation for DC cardioversion of atrial fibrillation. You plan on using propofol as the sedative agent.Propofol works as a result of action on what type of receptor? Select ONE answer only.
Your Answer: Gamma-aminobutyric acid (GABA)
Explanation:Propofol (2,6-diisopropylphenol) is a short-acting phenol derivative that is primarily used for the induction of anaesthesia.Its mechanism of action is unclear but is thought to act by potentiating the inhibitory neurotransmitters GABA and glycine, which enhances spinal inhibition during anaesthesia.The dose for induction of anaesthesia is 1.5-2.5mg/kg. The dose for maintenance of anaesthesia is 4-12 mg/kg/hour. Following intravenous injection, propofol acts within 30 seconds and its duration of action is 5-10 minutes.Propofol produces a 15-25% decrease in blood pressure and systemic vascular resistance without a compensatory increase in heart rate. It is negatively inotropic and decreases cardiac output by approximately 20%.The main side effects of propofol are:Pain on injection (in up to 30%)HypotensionTransient apnoeaHyperventilationCoughing and hiccoughHeadacheThrombosis and phlebitis
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 22
Correct
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A 30-year-old man bought into the ED with increased thirst, confusion, abdominal pain and constipation is suspected to have hypercalcaemia.What is the commonest cause of hypercalcaemia in the UK?
Your Answer: Primary hyperparathyroidism
Explanation:The commonest cause of hypercalcaemia in the UK is primary hyperparathyroidism, which accounts for around 70-80% of cases. It is commoner in younger patients and in community setting.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 23
Incorrect
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A study investigating the risk of suffering a stroke in patients with atrial fibrillation taking the new antiplatelet drug ticagrelor, compared with standard treatment with warfarin is done over a 2-year time period. 30 of the 300 patients taking ticagrelor and 20 of the 500 patients taking warfarin suffered a stroke over the 2-year period. One of these statements is true regarding the outcomes of this study.
Your Answer: The relative risk is 0.4
Correct Answer: Ticagrelor increases the risk of stroke
Explanation:Absolute risk and relative risk are used to assess the strength of a relationship between a disease and a factor that may affect it.Absolute risk (AR) is the risk of developing a disease over a time period:AR = the number of events that occur in a group / number of people in that groupThe absolute risk reduction (ARR) is the difference between the absolute risk in the control group (ARC) and the absolute risk in the treated group (ART). ARR = ARC – ARTThe control group is the warfarin group, therefore the ARC is 20/500 (0.04). Treatment group is the ticagrelor group and ART = 30/300 (0.1). ARR = 0.04 – 0.1 = -0.06. This shows that treatment with ticagrelor increases risk of developing stroke. This is also termed a relative risk increase.Relative risk, or risk ratio, (RR) is used to compare the risk in the two different groups. It is the ratio of the absolute risks of the disease in the treatment group (ART) to the absolute risk of the disease in the control group (ARC):RR=ART /ARCTherefore RR = 0.1 / 0.04 = 2.5RR < 1 means the intervention reduces the risk of the outcome being studiedRR = 1 means the treatment has no effect on the outcome being studiedRR > 1 means the intervention increased the risk of the outcome being studiedSince RR is 2.5, ticagrelor increases the risk of stroke.SUMMARYAbsolute risk reduction is -0.06Absolute risk in warfarin group = 0.04Relative risk = 2.5Ticagrelor has no effect on stroke is incorrect because RR is not =1
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This question is part of the following fields:
- Evidence Based Medicine
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Question 24
Incorrect
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An analytical cohort study aimed to determine a relationship between intake of dietary calcium and incidence of hip fractures among post-menopausal women. The following are the data obtained from the study:No. of post-menopausal women who took Calcium: 500No. of post-menopausal women who took Calcium and suffered a hip fracture: 10No. of post-menopausal women who took placebo: 500No. of post-menopausal women who took placebo and suffered a hip fracture: 25Compute for the risk ratio of a hip fracture.
Your Answer: 0.04
Correct Answer: 0.4
Explanation:Relative risk (RR) is a ratio of the probability of an event occurring in the exposed group versus the probability of the event occurring in the non-exposed group.RR can be computed as the absolute risk of events in the treatment group (ART), divided by the absolute risk of events in the control group (ARC).RR = ART/ARCRR = (10/500) / (25/500)RR = 0.4Recall that:If RR < 1, then the intervention reduces the risk of the outcome.If RR = 1, then the treatment has no effect on the outcome.If RR > 1, then the intervention increases the risk of the outcome.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 25
Incorrect
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A 30-year-old woman was involved in a road traffic accident and had a class I haemorrhage.Which physiological parameter is consistent with a diagnosis of class I haemorrhage?
Your Answer: 25% of blood volume lost
Correct Answer: Increased pulse pressure
Explanation:There are 4 classes of haemorrhage. Classification is based on clinical signs and physiological parameters.In CLASS I:Blood loss (ml) is < or = 750Blood loss(% blood volume) < or = 15%Pulse rate (bpm) is 30Pulse pressure is normal or increasedSystolic BP is normalCNS/mental status patient is slightly anxious In CLASS II:Blood loss (ml) is 750 – 1500Blood loss(% blood volume) is 15 – 30%Pulse rate (bpm) is 100 – 120Respiratory rate is 20-30Urine output (ml/hr) is 20-30Pulse pressure is decreasedSystolic BP is normalCNS/mental status patient is mildly anxiousIn CLASS III:Blood loss (ml) is 1500 – 2000Blood loss(% blood volume) is 30- 40%Pulse rate (bpm) is 120 – 140Respiratory rate is 30-40Urine output (ml/hr) is 5-15Pulse pressure is decreasedSystolic BP is decreasedCNS/mental status patient is anxious, confusedIn CLASS IV:Blood loss (ml) is >2000Blood loss(% blood volume) is >40%Pulse rate (bpm) is >140Respiratory rate is >40Urine output (ml/hr) is negligiblePulse pressure is decreasedSystolic BP is decreasedCNS/mental status patient is confused, lethargic
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This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
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Question 26
Correct
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Gastric emptying is inhibited by all of the following EXCEPT for:
Your Answer: Parasympathetic stimulation
Explanation:Gastric emptying is decreased by: Enterogastric inhibitory reflexes stimulated by – Distension of the duodenum, The presence of fats in the duodenum (by stimulating release of cholecystokinin), A fall in the pH of chyme in the duodenum, An increase in the osmolality of chyme in the duodenum, Irritation of the mucosal lining of the duodenum, Hormones: Cholecystokinin, Secretin
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 27
Correct
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In the treatment of bradyarrhythmias with adverse characteristics or risk of asystole, what is the initial suggested dose of atropine?
Your Answer: 500 micrograms
Explanation:Atropine 500 mcg IV bolus should be administered if there are any adverse features or risk of asystole. If the reaction is not adequate, repeat the steps every 3 to 5 minutes up to a maximum dose of 3 mg. In the case of acute myocardial ischemia or myocardial infarction, atropine should be taken with caution since the increased heart rate may aggravate the ischemia or increase the size of the infarct.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 28
Correct
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A 25-year-old man suffers from a shoulder injury that damaged the nerve that innervates the infraspinatus muscle.Which of the following nerves may most likely be affected?
Your Answer: The suprascapular nerve
Explanation:The suprascapular nerve (C5-C6) innervates the infraspinatus. It originates at the superior trunk of the brachial plexus. It runs laterally across the lateral cervical region to supply the infraspinatus and also the supraspinatus.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 29
Correct
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Cefotaxime (or ceftriaxone) is used first line for which of the following infections:
Your Answer: Blind treatment of suspected bacterial meningitis
Explanation:Cefotaxime (or ceftriaxone) are indicated first line in:- Blind treatment of meningitis in patients > 3 months (with amoxicillin if patient > 50 years)- Meningitis caused by meningococci- Meningitis caused by pneumococci- Meningitis caused by H. influenzae- Severe or invasive salmonellosis- Typhoid fever- Gonorrhoea- Gonococcal arthritis- Haemophilus influenzae epiglottitis
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 30
Incorrect
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At which opioid receptors do opioid analgesics act primarily?
Your Answer: Delta
Correct Answer: Mu
Explanation:Opioid receptors are widely distributed throughout the central nervous system. Opioid analgesics mimic endogenous opioid peptides by causing prolonged activation of these receptors, mainly the mu(μ)-receptors which are the most highly concentrated in brain areas involved in nociception.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 31
Correct
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Question 32
Incorrect
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Which of the following is typically a cause of a normal anion gap metabolic acidosis:
Your Answer: Propylene glycol overdose
Correct Answer: Diarrhoea
Explanation:FUSEDCARS can be used to remember some of the causes of a normal anion gap acidosis:Fistula (pancreaticoduodenal)Ureteroenteric conduitSaline administrationEndocrine (hyperparathyroidism)DiarrhoeaCarbonic anhydrase inhibitors (e.g. acetazolamide)Ammonium chlorideRenal tubular acidosisSpironolactone
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This question is part of the following fields:
- Physiology
- Renal
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Question 33
Correct
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A 16-year old boy is brought to the emergency room after suffering a traffic accident. Upon examination, there is noted ipsilateral loss of proprioception and vibration, ipsilateral motor loss, and contralateral loss of pain and temperature sensation. A spinal cord injury is given as a diagnosis.Which of the following is the most probable cause of this manifestation?
Your Answer: Brown-Séquard syndrome
Explanation:Brown-Sequard Hemicord Syndrome consists of ipsilateral weakness (corticospinal tract) and loss of joint position and vibratory sense (posterior column), with contralateral loss of pain and temperature sense (spinothalamic tract) one or two levels below the lesion. Segmental signs, such as radicular pain, muscle atrophy, or loss of a deep tendon reflex, are unilateral. Partial forms are more common than the fully developed syndrome.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 34
Correct
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You've been summoned to the resuscitation area to assist a patient who is having a seizure. As part of the treatment protocol, a benzodiazepine dose is given.Which of the following statements about the use of benzodiazepines in seizures is correct?
Your Answer: Lorazepam can be given by the rectal route
Explanation:A single dose of IV benzodiazepine will terminate the seizure in 60 to 80 percent of patients who present with seizures.Because benzodiazepines are lipid-soluble, they cross the blood-brain barrier quickly. This explains their quick onset of action.As a first-line treatment, IV lorazepam should be given. If IV lorazepam is not available, IV diazepam can be used instead, and buccal midazolam can be used if intravenous access cannot be established quickly. Lorazepam can be administered via the rectal route, but it is less reliable and has a lower absorption rate and bioavailability.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 35
Incorrect
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A newborn baby girl is delivered vaginally to a 19-year old female, however with complications due to cephalopelvic disproportion. Upon examination by the attending paediatrician, there is a notable 'claw hand' deformity of the left, and sensory loss of the ulnar aspect of the left distal upper extremity.What is the most probable diagnosis of the case above?
Your Answer: Erb’s palsy
Correct Answer: Klumpke’s palsy
Explanation:Klumpke palsy, named after Augusta Dejerine-Klumpke, is a neuropathy involving the lower brachial plexus. In contrast, the more common Erb–Duchenne palsy involves the more cephalic portion of the brachial plexus C5 to C6. The brachial plexus is a bundle of individual nerves that exit between the anterior and middle scalene muscles in the anterior lateral and basal portion of the neck. Although the most common anatomical presentation of the brachial plexus is between the anterior and middle scalene, there are variations, with the most common being penetration of the anterior scalene. The main mechanism of injury to the lower brachial plexus is hyper-abduction traction, and depending on the intensity, it will lead to signs and symptoms consistent with a neurological insult.The most common aetiology resulting in Klumpke palsy is a hyper-abduction trauma to the arm that has enough intensity to traction the lower brachial plexus. Trauma during birth can cause brachial plexus injuries, but again hyper-abduction and traction forces to the upper extremity are usually present.The history presented by the patient usually depicts a long axis hyper-abduction traction injury with high amplitude and velocity. The typical patient presentation is a decrease of sensation along the medial aspect of the distal upper extremity along the C8 and T1 dermatome. The patient might also present myotome findings that can range from decreasing muscular strength to muscular atrophy and positional deformity. For example, if the neurological damage has led to muscular atrophy and tightening, the patient may present with a claw hand. This deformity presents a finger and wrist flexion. The patient may also describe the severe pain that starts at the neck and travels down the medial portion of the arm. One other sign of a lower brachial plexus injury is Horner syndrome; because of its approximation to the T1 nerve root, it may damage the cephalic sympathetic chain. If this happens, the patient will develop ipsilateral ptosis, anhidrosis, and miosis.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 36
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 37
Incorrect
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A patient suffers from an injury and as a consequence, the nerve that was damaged innervates the obturator internus muscle.In which of the following nerves is the obturator internus muscle innervated by?
Your Answer: Sciatic nerve
Correct Answer: Nerve to obturator internus
Explanation:The obturator internus is innervated by the obturator internus nerve (L5–S2), a branch of sacral plexus.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 38
Incorrect
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What type of visual field defect are you likely to see in a lesion of the visual cortex:
Your Answer: Bitemporal hemianopia
Correct Answer: Contralateral homonymous hemianopia with macular sparing
Explanation:A lesion of the visual cortex will result in a contralateral homonymous hemianopia with macular sparing.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 39
Correct
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Which of the following statements is correct regarding the lymphatic system?
Your Answer: Lymphatic vessels contain both smooth muscle and unidirectional valves.
Explanation:Fluid filtration out of the capillaries is usually slightly greater than fluid absorption into the capillaries. About 8 L of fluid per day is filtered by the microcirculation and returns to the circulation by the lymphatic system. Lymphatic capillaries drain into collecting lymphatics, then into larger lymphatic vessels. Both of these containing smooth muscle and unidirectional valves. From this point, lymph is propelled by smooth muscle constriction and vessel compression by body movements into afferent lymphatics. It then goes to the lymph nodes where phagocytes remove bacteria and foreign materials. It is here that most fluid is reabsorbed by capillaries, and the remainder returns to the subclavian veins via efferent lymphatics and the thoracic duct. The lymphatic system has a major role to play in the body’s immune defence and also has a very important role in the absorption and transportation of fats.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 40
Correct
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Which of the following immunoglobulins is most important for mast cell degranulation:
Your Answer: IgE
Explanation:IgA is the major Ig in secretions, particularly from the gastrointestinal tract (but also in saliva, tears, sweat and breast milk).IgE is important for mast cell degranulation in allergic and antiparasitic response. In the allergic response, the plasma cell produces IgE-antibodies, which, like antibodies of other immunoglobulin isotypes, are capable of binding a specific allergen via its Fab portion.IgG is the most abundant in plasma (comprising 80% of normal serum immunoglobulin) and the main circulatory Ig for the secondary immune response.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 41
Correct
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All of the muscles of the tongue (other than the palatoglossus) are innervated by which of the following nerves:
Your Answer: Hypoglossal nerve
Explanation:All of the muscles of the tongue are innervated by the hypoglossal nerve, except for the palatoglossus, which is innervated by the vagus nerve.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 42
Correct
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For a tachyarrhythmia caused by hypovolaemic shock, which of the following is the first-line treatment:
Your Answer: Synchronised DC shock
Explanation:If there are any adverse symptoms, immediate cardioversion with synchronized DC shock is recommended. If cardioversion fails to stop the arrhythmia and the symptoms persist, amiodarone 300 mg IV over 10–20 minutes should be administered before attempting another cardioversion. The loading dosage of amiodarone is followed by a 24-hour infusion of 900 mg administered into a large vein.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 43
Incorrect
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Which of the following statements is incorrect regarding the Na+/K+ATPase pump?
Your Answer: The Na + /K + ATPase pump uses energy derived from ATP hydrolysis.
Correct Answer: The Na + /K + ATPase pump moves 3 Na + ions into the cell for every 2 K + ions out.
Explanation:In order for primary active transport to pump ions against their electrochemical gradient, chemical energy is used in the form of ATP. The Na+/K+-ATPase antiporter pump uses metabolic energy to move 3 Na+ions out of the cell for every 2 K+ions in, against their respective electrochemical gradients. As a result, the cell the maintains a high intracellular concentration of K+ions and a low concentration of Na+ions.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 44
Incorrect
-
Gastrin primarily acts to perform which of the following functions:
Your Answer: Inhibit gastric emptying
Correct Answer: Stimulate gastric acid secretion
Explanation:Gastrin primarily  acts to stimulate acid secretion from parietal cells (both directly and indirectly by stimulating release of histamine from ECL cells).
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 45
Correct
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Which of the following statements is correct with regards to Klebsiella spp?
Your Answer: They are typically associated with nosocomial infection.
Explanation:Klebsiella is a type of bacteria commonly found in nature. In humans, the bacteria are often present in parts of the digestive tract and respiratory flora, where they do not generally cause problems. They are anaerobic Gram-negative rods. They are usually opportunistic pathogens which cause nosocomial infections, the most common ones being pneumonia and UTI.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 46
Incorrect
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What is the direct mechanism of action of digoxin as a positive inotrope:
Your Answer: Inhibition of Na+/Ca2+ exchanger
Correct Answer: Inhibition of Na+/K+ ATPase pump
Explanation:Digoxin directly inhibits membrane Na+/K+ ATPase, which is responsible for Na+/K+ exchange across the myocyte cell membrane. This increases intracellular Na+ and produces a secondary increase in intracellular Ca2+ that increases the force of myocardial contraction. The increase in intracellular Ca2+ occurs because the decreased Na+ gradient across the membrane reduces the extrusion of Ca2+ by the Na+/Ca2+ exchanger that normally occurs during diastole. Digoxin and K+ ions compete for the receptor on the outside of the muscle cell membrane, and so the effects of digoxin may be dangerously increased in hypokalaemia.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 47
Incorrect
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Regarding bile acids, which of the following statements is INCORRECT:
Your Answer: Of the bile acids excreted into the intestine, about 95% are reabsorbed.
Correct Answer: The main primary bile acids are deoxycholic acid and lithocholic acid.
Explanation:Bile acids have a hydrophobic and a hydrophilic end and in aqueous solution, bile salts orient themselves around droplets of lipid forming micelles to keep the lipid droplets dispersed. The principal primary bile acids are cholic acid and chenodeoxycholic acid. They are made more soluble by conjugation with taurine or glycine in the liver. Of the bile acids excreted into the intestine, about 95% are reabsorbed into the portal circulation by active transport mechanisms in the distal ileum and recycled by the liver.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 48
Correct
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Which of the following is NOT a common myeloma laboratory finding:
Your Answer: Elevated serum Bence-Jones protein
Explanation:Myeloma laboratory findings include:- The presence of a paraprotein in serum or urine (the paraprotein is IgG in 60 percent of cases, IgA in 20 percent, and light chain only in almost all the rest),- Increased serum immunoglobulin-free light chain proteins generated by plasma cells but not coupled with heavy chains – Reduced IgG, IgA, and IgM levels in the blood (immune paresis)- Anaemia, whether normochromic, normocytic, or macrocytic. – On a blood film, a Rouleaux formation has been marked. – In advanced illness, neutropenia and thrombocytopenia are common. – ESR is high. – Plasma cells in the bone marrow are overabundant, typically in aberrant forms. – Hypercalcemia- Creatinine levels are high. – Serum albumin levels are low in advanced illness. 60 percent of patients have osteolytic lesions, osteoporosis, or pathological fractures.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 49
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: Lymphopenia
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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Question 50
Incorrect
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You examine a 50-year-old female who has a swollen, painful right big toe. She has a history of gout, and this discomfort is identical to prior relapses, according to her. She is currently taking 200 mg of allopurinol per day and has been for the last year. This is her second round of acute gout within this time period. She has no prior medical history to speak of and does not take any other medications. She doesn't have any known drug allergies.Which of the following management options is the SINGLE MOST APPROPRIATE?Â
Your Answer: Continue with the allopurinol and commence colchicine
Correct Answer: Continue with the allopurinol and commence naproxen
Explanation:Allopurinol should not be started during an acute gout episode because it can both prolong and trigger another acute attack. Allopurinol should be continued in patients who are currently taking it, and acute attacks should be treated as usual with NSAIDs or colchicine, as needed.Non-steroidal anti-inflammatory medications (NSAIDs), such as naproxen, are the first-line treatment for acute gout attacks. Colchicine can be used in situations where NSAIDs are contraindicated, such as in patients with hypertension or those who have had a history of peptic ulcer disease. Because there is no reason for this patient to avoid NSAIDs, naproxen would be the medicine of choice from the list above.It would be reasonable to titrate up the allopurinol dose once the acute episode has subsided, targeting <6 mg/dl (<360 µmol/l) plasma urate levels .Febuxostat (Uloric) is a drug that can be used instead of allopurinol to treat persistent gout.
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This question is part of the following fields:
- Musculoskeletal Pharmacology
- Pharmacology
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Question 51
Incorrect
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A 35-year-old man presents with haemoptysis, night sweats, and weight loss. Further examinations were done and a diagnosis of tuberculosis is suspected. Which of the following statements is considered correct regarding Mycobacterium tuberculosis?
Your Answer: It Gram stains red
Correct Answer: It is impervious to decolourisation with acid
Explanation:Mycobacterium tuberculosis are part of the Mycobacteriaceae family. They are described to have the characteristics of a Gram-positive cell wall but they are not easily stained with Gram stain. This is because their cell wall contains a high lipid content, and this lipid allows the Mycobacteria to bind to alkaline stains with the application and help of heat. Once stained, they are able to resist decolorization even with the use of acid alcohol as the decolourizer, making them very difficult to decolorize, that is why they are known to be acid-fast.The Ghon complex is a non-pathognomonic radiographic finding on a chest x-ray that is significant for pulmonary infection of tuberculosis. The location of the Ghon’s focus is usually subpleural and predominantly in the upper part of the lower lobe and lower part of the middle or upper lobe. Skeletal tuberculosis of the spine is referred to as Pott disease.The risk of reactivation TB is about 3.3% during the first year after a positive PPD skin test and a total of 5% to 15% thereafter in the person’s lifetime. Progression from infection to active disease varies with age and the intensity and duration of exposure. Reactivation TB occurs when there is an alteration or suppression of the cellular immune system in the infected host that favoursreplication of the bacilli and progression to disease.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 52
Incorrect
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Regarding carbohydrate, which of the following statements is INCORRECT:
Your Answer: Glycogen is derived from animal sources.
Correct Answer: Most dietary carbohydrate is in the form of disaccharides.
Explanation:Carbohydrates are the main energy source of most diets. They provide 17 kJ (4 kcal) of energy per gram. Most dietary carbohydrate is in the form of polysaccharides. The principal ingested polysaccharides are starch which is derived from plant sources and glycogen which is derived from animal sources. Dietary fibre consists of indigestible carbohydrate (found in plant foods) such as cellulose, lignin and pectin.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 53
Incorrect
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In the emergency room, a patient was diagnosed with acute bacterial tonsillitis. Which of the following postinfectious complications is most commonly linked to Streptococcus pyogenes:
Your Answer: Guillain-Barre syndrome
Correct Answer: Glomerulonephritis
Explanation:Poststreptococcal glomerulonephritis (PSGN) is caused by prior infection with specific nephritogenic strains of group A beta-haemolytic streptococcus. The clinical presentation of PSGN varies from asymptomatic, microscopic haematuria to the full-blown acute nephritic syndrome, characterized by red to brown urine, proteinuria (which can reach the nephrotic range), oedema, hypertension, and acute kidney injury.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 54
Incorrect
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The most important nerve for plantar flexion of the foot at the ankle joint is:
Your Answer: Deep fibular nerve
Correct Answer: Tibial nerve
Explanation:Muscles of the posterior compartment of the leg, innervated by the tibial nerve, perform plantar flexion of the foot at the ankle joint. The fibularis longus (innervated by the superficial fibular nerve) assists in plantar flexion but is not the most important.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 55
Incorrect
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Oedema can occur as a result of any of the following WITH THE EXCEPTION OF:
Your Answer: Decreased plasma oncotic pressure
Correct Answer: Increased interstitial hydrostatic pressure
Explanation:Oedema is defined as a palpable swelling produced by the expansion of the interstitial fluid volume. A variety of clinical conditions are associated with the development of oedema, including heart failure, cirrhosis, and nephrotic syndrome. The development of oedema requires an alteration in capillary dynamics in a direction that favours an increase in net filtration and also inadequate removal of the additional filtered fluid by lymphatic drainage. Oedema may form in response to an elevation in capillary hydraulic pressure (which increases the delta hydraulic pressure) or increased capillary permeability, or it can be due to disruption of the endothelial glycocalyx, decreased interstitial compliance, a lower plasma oncotic pressure (which reduces the delta oncotic pressure), or a combination of these changes. Oedema can also be induced by lymphatic obstruction since the fluid that is normally filtered is not returned to the systemic circulation.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 56
Correct
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Which of the following clinical features is most suggestive of a lesion of the frontal lobe:
Your Answer: Conjugate eye deviation towards the side of the lesion
Explanation:Conjugate eye deviation towards the side of the lesion is seen in damage to the frontal eye field of the frontal lobe. Homonymous hemianopia is typically a result of damage to the occipital lobe (or of the optic radiation passing through the parietal and temporal lobes). Auditory agnosia may been seen in a lesion of the temporal lobe. Hemispatial neglect may be seen in a lesion of the parietal lobe. Receptive dysphasia is seen in damage to Wernicke’s area, in the temporal lobe.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 57
Incorrect
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A 68-year-old patient shows Low calcium levels and is on dialysis for chronic kidney disease.What percentage of total serum calcium is in the form of free or ionised Ca 2+?
Your Answer: 90%
Correct Answer: 50%
Explanation:Approximately half of total serum calcium is in the free or ionised Ca2+ state, 40% is attached to plasma proteins (mostly albumin), and the remaining 10% is in complexes with organic ions like citrate and phosphate. The ionized form is the only one that works.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 58
Correct
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What is the primary function of the mitochondria?
Your Answer: The production of the cell's supply of chemical energy
Explanation:The mitochondria is responsible for the production of the cell’s supply of chemical energy. It does this by using molecular oxygen, sugar and small fatty acid molecules to generate adenosine triphosphate (ATP) by a process ss known as oxidative phosphorylation. An enzyme called ATP synthase is required. Transcription of ribosomal RNA occurs in the nucleolusProduction of messenger RNA occur in the nucleusProduction of lysosome occurs in the Golgi apparatusThe post-translational processing of newly made proteins occurs in the endoplasmic reticulum
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 59
Incorrect
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Antidiuretic hormone (ADH) levels are found to be increased in a young lady with unexplained hyponatraemia.In a healthy patient under normal circumstances, in which of the following conditions would ADH not be released?Â
Your Answer: Increased circulating Angiotensin II
Correct Answer: Increased alcohol intake
Explanation:Antidiuretic hormone (ADH) is produced in the hypothalamus’s supraoptic nucleus and then released into the blood via axonal projections from the hypothalamus to the posterior pituitary.It is carried down axonal extensions from the hypothalamus (the neurohypophysial capillaries) to the posterior pituitary, where it is kept until it is released, after being synthesized in the hypothalamus.The secretion of ADH from the posterior pituitary is regulated by numerous mechanisms:Increased plasma osmolality: Osmoreceptors in the hypothalamus detect an increase in osmolality and trigger ADH release.Hypovolaemia causes a drop in atrial pressure, which stretch receptors in the atrial walls and big veins detect (cardiopulmonary baroreceptors). ADH release is generally inhibited by atrial receptor firing, but when the atrial receptors are stretched, the firing reduces and ADH release is promoted.Hypotension causes baroreceptor firing to diminish, resulting in increased sympathetic activity and ADH release.An increase in angiotensin II stimulates angiotensin II receptors in the hypothalamus, causing ADH production to increase.Nicotine, Sleep, Fright, and Exercise are some of the other elements that might cause ADH to be released.Alcohol (which partly explains the diuretic impact of alcohol) and elevated levels of ANP/BNP limit ADH release.
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 60
Incorrect
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Regarding gastric motility and emptying, which of the following statements is CORRECT:
Your Answer: Cholecystokinin enhances gastric motility and gastric emptying.
Correct Answer: Gastric emptying is inhibited by the presence of the products of fat digestion in the duodenum.
Explanation:Gastric emptying is decreased by the presence of fats in the duodenum (by stimulating release of cholecystokinin). Mixing of the food with gastric secretions takes place in the distal body and antrum of the stomach where the muscularis externa layer is thicker. The stomach has an additional inner oblique smooth muscle layer (in addition to the inner circular layer and outer longitudinal layer). Gastric emptying is increased by a low gastric pH and decreased by a low duodenal pH.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 61
Incorrect
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The most important Complement protein for antigen opsonization is:
Your Answer: C5b
Correct Answer: C3b
Explanation:Phagocytosis is largely responsible for depletion of cells coated with antibodies. Cells opsonized by IgG antibodies are recognized by phagocyte Fc receptors, which are specific for the Fc portions of some IgG subclasses. In addition, when IgM or IgG antibodies are deposited on the surfaces of cells, they may activate the complement system by the classical pathway. Complement activation generates by-products, mainly C3b and C4b, which are deposited on the surfaces of the cells and recognized by phagocytes that express receptors for these proteins. The net result is phagocytosis of the opsonized cells and their destruction.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 62
Incorrect
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Which of the following is NOT a typical feature of an abducens nerve palsy:
Your Answer: Loss of abduction
Correct Answer: Inability to look up
Explanation:CN VI palsies result in a convergent squint at rest (eye turned inwards) with inability to abduct the eye because of unopposed action of the rectus medialis. The patient complains of horizontal diplopia when looking towards the affected side. With complete paralysis, the eye cannot abduct past the midline.
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This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
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Question 63
Incorrect
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You review a patient with a history of Addison’s disease. He takes 100 mg of hydrocortisone per day to control this.What dose of prednisolone is equivalent to this dose of hydrocortisone? Select ONE answer only.
Your Answer: 50 mg
Correct Answer: 25 mg
Explanation:Prednisolone is four times more potent than hydrocortisone, and therefore, a dose of 25 mg would be equivalent to 100 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 64
Incorrect
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Following the administration of a drug that was started a few months earlier, a patient presents with features of peripheral neuropathy.Which of the following drugs is most likely to cause peripheral neuropathy?
Your Answer: Amiodarone
Correct Answer: Isoniazid
Explanation:Isoniazid, a first-line agent for the treatment of tuberculosis, has the commonest side effect of peripheral neuropathy. It occurs in up to 20% of patients taking the drug at a dose > 6 mg/kg daily. Isoniazid combines with pyridoxine (vitamin B6) to form hydrazone, which is excreted in the urine. This causes a deficiency of biologically active pyridoxine leading to peripheral neuropathy.Peripheral neuropathy of isoniazid is prevented by the co-administration of pyridoxine at a dose of 10 mg for each 100 mg of isoniazid given.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 65
Incorrect
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Digoxin exhibits its positive inotropic effect by which of the following mechanisms:
Your Answer: Activates Ca2+ release channels on the sarcoplasmic reticulum
Correct Answer: Inhibits the Na+/K+ pump on the myocyte membrane
Explanation:Cardiac glycosides (e.g. digoxin) slow the removal of Ca2+from the cell by inhibiting the membrane Na+pump (Na+/K+ATPase) which generates the Na+gradient required for driving the export of Ca2+by Na+/Ca2+exchange; consequently the removal of Ca2+from the myocyte is slowed and more Ca2+is available for the next contraction.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 66
Incorrect
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An analytical cohort study aimed to determine a relationship between intake of dietary calcium and incidence of hip fractures among post-menopausal women. The following are the data obtained from the study:No. of post-menopausal women who took Calcium: 500No. of post-menopausal women who took Calcium and suffered a hip fracture: 10No. of post-menopausal women who took placebo: 500No. of post-menopausal women who took placebo and suffered a hip fracture: 25Compute for the absolute risk in the placebo group.
Your Answer: 0.02
Correct Answer: 0.05
Explanation:The absolute risk (AR) is the probability or chance of an event. It is computed as the number of events in treated or control groups, divided by the number of people in that group.AR = 25/500 = 0.05
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This question is part of the following fields:
- Evidence Based Medicine
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Question 67
Correct
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A dermatological examination of a patient presenting with a lump shows a visible collection of fluid measuring 0.3 cm in diameter.Which one of these best describes the lump you have found on examination?
Your Answer: Vesicle
Explanation:A vesicle is a visible collection of fluid measuring less than 0.5 cm in diameter.A furuncle, or boil, is a pyogenic infection of the hair follicle commonly caused by infection with Staphylococcus aureus. A carbuncle is a collection of individual boils clustered together. A bulla is a visible collection of clear fluid measuring greater than 0.5 cm in diameter. A pustule is a small visible skin elevation containing an accumulation of pus.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 68
Incorrect
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Which of the following is NOT a common side effect of diazepam:
Your Answer: Amnesia
Correct Answer: Bradycardia
Explanation:Adverse effects include:Drowsiness and lightheadednessConfusion and ataxia (especially in the elderly), amnesia, muscle weaknessHeadache, vertigo, tremor, dysarthria, hypotension, decreased libido, erectile dysfunction, gynaecomastia, urinary retentionParadoxical effects such as talkativeness, excitement, irritability, aggression, anti-social behaviour, and suicidal ideationWithdrawal symptoms, for example anxiety, depression, anorexia, impaired concentration, insomnia, abdominal cramps, palpitations, tremor, tinnitus and perceptual disturbancesTolerance and dependence (people who use benzodiazepines longer term can develop tolerance and eventual dependence)
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 69
Incorrect
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Which of these statements about the monospot test is true?
Your Answer: It is positive in infectious mononucleosis before the onset of symptoms
Correct Answer: It can be positive in rubella
Explanation:Infectious mononucleosis can be diagnosed using specific EBV antibodies and a variety of unrelated non-EBV heterophile antibodies.Heterophile antibodies:About 70-90% of patients with EBV infectious mononucleosis produce antibodies against an antigen produced in one species that react against antigens from other species called heterophile antibodies. False positives can be seen with rubella, hepatitis, SLE, malaria, toxoplasmosis, lymphoma and leukaemia. These antibodies can be detected by two main screening tests:The monospot test uses horse red blood cells. It agglutinates in the presence of heterophile antibodies.Paul-Bunnell test uses sheep red blood cells. The blood agglutinates in the presence of heterophile antibodies.EBV-specific antibodies:Patients can remain heterophile-negative after six weeks and are then considered to be heterophile-negative and should be tested for EBV-specific antibodies. EBV-specific antibodies test are helpful if a false positive heterophile antibody test is suspected.The indirect Coombs test is used to detect in-vitro antibody-antigen reactions. It is typically used in antenatal antibody screening and in preparation for blood transfusion.Heterophile antibody tests are generally not positive in the incubation period of infectious mononucleosis (4-6 weeks) before the onset of symptoms.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 70
Correct
-
Beta cells of the endocrine pancreas produce which of the following hormones:
Your Answer: Insulin
Explanation:Insulin is produced by beta cells, located centrally within the islets of Langerhans, in the endocrine tissues of the pancreas. Insulin is a polypeptide hormone consisting of two short chains (A and B) linked by disulphide bonds. Proinsulin is synthesised as a single-chain peptide. Within storage granules, a connecting peptide (C peptide) is removed by proteases to yield insulin. Insulin release is stimulated initially during eating by the parasympathetic nervous system and gut hormones such as secretin, but most output is driven by the rise in plasma glucose concentration that occurs after a meal. The effects of insulin are mediated by the receptor tyrosine kinase.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 71
Correct
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After a work-related accident, a 33-year old male is taken to the emergency room with difficulty in adduction and flexion of his left arm at the glenohumeral joint. The attending physician is suspects involvement of the coracobrachialis muscle.The nerve injured in the case above is?
Your Answer: The musculocutaneous nerve
Explanation:The coracobrachialis muscle is innervated by the musculocutaneous nerve (C5-C7) a branch of the lateral cord of the brachial plexus.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 72
Incorrect
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A 26 year old horse rider has a bad fall and sustains a neck injury which displays the following signs:- ability to extend the wrist against gravity- paralysis of the hands, trunk, and legs- absent sensation in the fingers and medial upper arms- normal sensation over the thumbs- absent sensation in chest, abdomen, and legsWhat is the neurological level of the injury?
Your Answer: C7
Correct Answer: C6
Explanation:C1 – C4 INJURYMost severe of the spinal cord injury levels; paralysis in arms, hands, trunk and legs; patient may not be able to breathe on his or her own, cough, or control bowel or bladder movements; ability to speak is sometimes impaired or reducedC5 INJURYPerson can raise his or her arms and bend elbows; likely to have some or total paralysis of wrists, hands, trunk and legs; can speak and use diaphragm, but breathing will be weakenedC6 INJURYNerves affect wrist extension; paralysis in hands, trunk and legs, typically; should be able to bend wrists back; can speak and use diaphragm, but breathing will be weakenedC7 INJURYNerves control elbow extension and some finger extension; most can straighten their arm and have normal movement of their shouldersC8 INJURYNerves control some hand movement; should be able to grasp and release objectsC5 – Elbow flexors (biceps, brachialis)C6 – Wrist extensors (extensor carpi radialis longus and brevis)C7 – Elbow extensors (triceps)C8 – Finger flexors (flexor digitorum profundus) to the middle fingerC5 – Elbow flexed at 90 degrees, arm at the patient’s side and forearm supinatedC6 – Wrist in full extensionC7 – Shoulder is neutral rotation, adducted and in 90 degrees of flexion with elbow in 45 degrees of flexionC8 –Full flexed position of the distal phalanx with the proximal finger joints stabilized in a extended position
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 73
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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Question 74
Correct
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Regarding NSAIDs, which of the following statements is CORRECT:
Your Answer: Diclofenac is contraindicated in people with ischaemic heart disease.
Explanation:Due to their increased risk of cardiovascular adverse events, coxibs and diclofenac are contraindicated in people with ischaemic heart disease, cerebrovascular disease, peripheral arterial disease and mild, moderate, or severe heart failure. Other NSAIDs are only contraindicated in people with severe heart failure. Selective inhibition of COX-2 is associated with less gastrointestinal intolerance. In single doses NSAIDs have analgesic activity comparable to that of paracetamol, therefore given their side effect profile, paracetamol is preferred, particularly in the elderly. Pain relief starts soon after taking the first dose and a full analgesic effect should normally be obtained within a week, whereas an anti-inflammatory effect may not be achieved (or may not be clinically assessable) for up to 3 weeks. Mefenamic acid has only very mild anti-inflammatory properties.
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This question is part of the following fields:
- Musculoskeletal
- Pharmacology
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Question 75
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: Laryngeal constriction
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 76
Correct
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A 55-year-old male diabetic patient presents to the Emergency Room complaining of severe chest pain. His medical record shows that he had coronary angioplasty one week ago, during which he was administered abciximab. Which of the following haematological diseases has a similar mechanism of action to this drug?
Your Answer: Glanzmann’s thrombasthenia
Explanation:Abciximab is glycoprotein IIb/IIIa receptor antagonist that decreases aggregation of platelets by prevent their cross-linking. In Glanzmann’s thrombasthenia there are low levels of these same receptors leading to decreased bridging of platelets as fibrinogen cannot attach. There is increased bleeding time both in this disease and when there is use of abciximab.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 77
Incorrect
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A 28-year-old woman in her second trimester is diagnosed with a psychiatric illness. She is started on treatment with a drug. The treatment results in her baby being born with poor tone, feeding problems, hypothyroidism, and a goitreOut of the following, which drug is most likely responsible for the baby's condition?
Your Answer: Venlafaxine
Correct Answer: Lithium
Explanation:In pregnancy and postpartum, lithium is an effective treatment for relapse prevention in bipolar disorder. However, lithium has also been associated with risks during pregnancy for both the mother and the unborn child. Recent large studies have confirmed the association between first-trimester lithium exposure and an increased risk of congenital malformations.Lithium levels need to be monitored more frequently throughout pregnancy and the postnatal period. If given in the 1st-trimester, lithium is associated with a risk of fetal cardiac malformations, such as Ebstein’s anomaly. If given in the 2nd and 3rd-trimesters, there is a risk of the following:1. hypotonia2. lethargy3. feeding problems4. hypothyroidism5. goitre6. nephrogenic diabetes insipidus in the neonate
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 78
Correct
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The movement of molecules across the cell membrane relies greatly on active transport.Which of the following statements about active transport is correct?
Your Answer: Active transport occurs in glucose absorption from the gut
Explanation:The movement of a material against a concentration gradient, i.e. from a low to a high concentration, is known as active transport. Primary active transport is defined as active transport that involves the use of chemical energy, such as adenosine triphosphate (ATP). Secondary active transport occurs when an electrochemical gradient is used.The sodium-potassium pump, calcium ATPase pump, and proton pump are all key active transport systems that use ATP. An electrochemical gradient is used by the sodium-calcium co-transporter, which is an example of secondary active transport.The sodium-dependent hexose transporter SGLUT-1 transports glucose and galactose into enterocytes. Secondary active transport is exemplified here.
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 79
Correct
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A patient presents with an acute severe asthma attack. Following a poor response to his initial salbutamol nebuliser, you administer a further nebuliser that this time also contains ipratropium bromide.After what time period would you expect the maximum effect of the ipratropium bromide to occur? Select ONE answer only.
Your Answer: 30 -60 minutes
Explanation:Ipratropium bromide is an antimuscarinic drug used in the management of acute asthma and COPD. It can provide short-term relief in chronic asthma, but short-acting β2agonists act more quickly and are preferred.The BTS guidelines recommend that nebulised ipratropium bromide (0.5 mg 4-6 hourly) can be added to β2agonist treatment for patients with acute severe or life-threatening asthma or those with a poor initial response to β2 agonist therapy.The aerosol inhalation of ipratropium can be used for short-term relief in mild chronic obstructive pulmonary disease in patients who are not already using a long-acting antimuscarinic drug (e.g. tiotropium).Its maximum effect occurs 30-60 minutes after use; its duration of action is 3-6 hours, and bronchodilation can usually be maintained with treatment three times per day.The commonest side effect of ipratropium bromide is dry mouth. It can also trigger acute closed-angle glaucoma in susceptible patients. Tremor is commonly seen with β2agonists but not with antimuscarinics. Ipratropium bromide should be used with caution in: Men with prostatic hyperplasia and bladder-outflow obstruction (worsened urinary retention has been reported in elderly men), People with chronic kidney disease (CKD) stages 3 and above (because of the risk of drug toxicity), People with angle-closure glaucoma (nebulised mist of antimuscarinic drugs can precipitate or worsen acute angle-closure glaucoma)
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This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 80
Incorrect
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A 28-year-old medical student ate a reheated Chinese takeaway and developed severe vomiting a few hours after.What is the SINGLE MOST likely causative organism?
Your Answer: Salmonella enteritidis
Correct Answer: Bacillus cereus
Explanation:Bacillus cereusis is the correct answer. It is a Gram-positive, rod-shaped, beta-haemolytic bacterium that causes ‘fried rice syndrome’.Hardy spores in rice can survive boiling. When left at room temperature for long periods prior to frying these spores germinate. The emetic enterotoxin-producing strains cause nausea and vomiting between 1 and 6 hours after consumption while the diarrheagenic enterotoxin-producing strains (commonly associated with ingestion of meat, vegetables and dairy products) causes abdominal pain and vomiting, which starts 8-12 hours after ingestion.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 81
Incorrect
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Which of the following is most likely to cause a bitemporal hemianopia:
Your Answer: Frontal lobe tumour
Correct Answer: Pituitary adenoma
Explanation:A bitemporal hemianopia is most likely due to compression at the optic chiasm. This may be caused by pituitary tumour, craniopharyngioma, meningioma, optic glioma or aneurysm of the internal carotid artery. A posterior cerebral stroke will most likely result in a contralateral homonymous hemianopia with macular sparing.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 82
Correct
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A 28-year-old female arrives after taking an unknown chemical in excess. She is tired and her speech is slurred. The following are her observations and results: HR 118, BP 92/58, SaO2 96%HR 118, 11/15  The following are the results of his arterial blood gas (ABG):pH: 7.24 pO 2 : 9.4 kPa PCO2 : 3.3 kPa HCO 3 -: 22 mmol/l Na + : 143 mmol/l Cl – : 99 mmol/l Lactate: 5 IU/lWhich of the following statements about this patient is TRUE?
Your Answer: Her anion gap is elevated
Explanation:The interpretation of arterial blood gas (ABG) aids in the measurement of a patient’s pulmonary gas exchange and acid-base balance. The normal values on an ABG vary a little depending on the analyser, but they are roughly as follows:Variable RangepH 7.35 – 7.45PaO2 10 – 14 kPaPaCO2 4.5 – 6 kPaHCO3- 22 – 26 mmol/lBase excess -2 – 2 mmol/lThe patient’s history indicates that she has taken an overdose in this case. Because her GCS is 11/15 and she can communicate with slurred speech, she is clearly managing her own airway, there is no current justification for intubation.The following are the relevant ABG findings:Hypoxia (mild)pH has been lowered (acidaemia)PCO2 levels are low.bicarbonate in its natural stateLactate levels have increasedThe anion gap represents the concentration of all the unmeasured anions in the plasma. It is the difference between the primary measured cations and the primary measured anions in the serum. It can be calculated using the following formula:Anion gap = [Na+] – [Cl-] – [HCO3-]The reference range varies depending on the technique of measurement, but it is usually between 8 and 16 mmol/L.The following formula can be used to compute her anion gap:Anion gap = [143] – [99] – [22]Anion gap = 22As a result, it is clear that she has a metabolic acidosis with an increased anion gap.The following are some of the causes of type A and type B lactic acidosis:Type A lactic acidosisType B lactic acidosisShock (including septic shock)Left ventricular failureSevere anaemiaAsphyxiaCardiac arrestCO poisoningRespiratory failureSevere asthma and COPDRegional hypoperfusionRenal failureLiver failureSepsis (non-hypoxic sepsis)Thiamine deficiencyAlcoholic ketoacidosisDiabetic ketoacidosisCyanide poisoningMethanol poisoningBiguanide poisoning
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 83
Incorrect
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A 75-year-old man with rheumatoid arthritis had gained weight, developed resistant hypertension, muscle weakness, and ankle oedema. This patient is most likely suffering from what condition?
Your Answer: Pheochromocytoma
Correct Answer: Cushing's syndrome
Explanation:Overuse of cortisol medication, as seen in the treatment of patients with chronic asthma or rheumatoid arthritis, can cause Cushing’s syndrome. Weight gain, thin arms and legs, a round face, increased fat around the base of the neck, a fatty hump between the shoulders, easy bruising, wide purple stretch marks primarily on the abdomen, breasts, hips, and under the arms, weak muscles, hirsutism, hypertension, erectile dysfunction, osteoporosis, frontal alopecia, acne, depression, poor wound healing, and polycythaemia are all clinical features of Cushing’s syndrome.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 84
Incorrect
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A 28-year-old patient is intubated and has a central venous catheter inserted after being diagnosed with septic shock. You keep track of her central venous pressure.The normal value for central venous pressure is which of the following?Â
Your Answer: 8-15 cmH 2 O
Correct Answer: 0-8 cmH 2 O
Explanation:The pressure measured in the right atrium or superior vena cava is known as central venous pressure (CVP). In a spontaneously breathing subject, the usual CVP value is 0-8 cmH2O (0-6 mmHg).At the conclusion of expiration, the CVP should be measured with the patient resting flat. The catheter’s tip should be at the intersection of the superior vena cava and the right atrium. An electronic transducer is installed and zeroed at the level of the right atrium to measure it (usually in the 4th intercostal space in the mid-axillary line).CVP is a good predictor of preload in the right ventricle. Hypovolaemia is indicated by a volume challenge of 250-500 mL crystalloid eliciting an increase in CVP that is not sustained for more than 10 minutes.CVP is influenced by a number of factors, including:Mechanical ventilation (and PEEP)Pulmonary hypertensionPulmonary embolismHeart failurePleural effusionDecreased cardiac outputCardiac tamponadeCVP is reduced by the following factors:Distributive shockNegative pressure ventilationHypovolaemiaDeep inhalation
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This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
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Question 85
Correct
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A 59-year-old man presents to the emergency room with chest pain. He was recently released from the hospital after receiving abciximab during coronary angioplasty.Which of the following is abciximab (ReoPro) mechanism of action?
Your Answer: Antagonism of the glycoprotein IIb/IIIa receptor
Explanation:Abciximab (ReoPro) is a glycoprotein IIb/IIIa receptor antagonist that is a chimeric monoclonal antibody. It is primarily used during and after coronary artery procedures such as angioplasty to inhibit platelet aggregation.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 86
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 87
Correct
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A 59-year-old man presents with a goitre, increased sweating, weight loss, and palpitations. A diagnosis of hyperthyroidism is suspected.What is the most appropriate first-line investigation?
Your Answer: TSH level
Explanation:A thyroid function test is used in the diagnosis of hyperthyroidism.Serum TSH should be the first-line investigation for patients with suspected hyperthyroidism as it has the highest sensitivity and specificity for hyperthyroidism. A normal TSH level almost always excludes the diagnosis, though there are rare exceptions to this.Antithyroglobulin antibodies are commonly present in Graves’ disease, but the test has a sensitivity of 98% and specificity of 99, and is not widely available.Radioactive iodine uptake scan using iodine-123 – shows low uptake in thyroiditis but high in Graves’ disease and toxic multinodular goitre. It is however, not first-line investigation in this caseThyroid ultrasound scan – is a cost-effective and safe alternative to the radioactive iodine uptake scan.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 88
Correct
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A 27-year-old man has been diagnosed with testicular cancer and has spread to the regional lymph nodes. The lymph from the testes will drain to which of the following nodes?
Your Answer: Para-aortic lymph nodes
Explanation:Testes are retroperitoneal organs and its lymphatic drainage is to the lumbar and para-aortic nodes along the lumbar vertebrae.The scrotum is the one which drains into the nearby superficial inguinal nodes.The glans penis and clitoris drains into the deep inguinal lymph nodes.
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This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 89
Incorrect
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A patient suffers an injury to the nerve that innervates gluteus medius.​The gluteus medius muscle is innervated by which of the following nerves? Select ONE answer only.
Your Answer: Inferior gluteal nerve
Correct Answer: Superior gluteal nerve
Explanation:Gluteus minimus is innervated by the superior gluteal nerve.Gluteus medius is innervated by the superior gluteal nerve.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 90
Incorrect
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An analytical study is conducted to compare the risk of stroke between Ticagrelor therapy and Warfarin therapy among patients with atrial fibrillation. The following is obtained from the study:No. of patients who took Ticagrelor: 300No. of patients who took Ticagrelor and suffered a stroke: 30No. of patients who took Warfarin: 500No. of patients who took Warfarin and suffered a stroke: 20Compute for the absolute risk reduction of a stroke, with Warfarin as the standard of treatment.
Your Answer: 0.04
Correct Answer: -0.06
Explanation:Absolute risk reduction (ARR) is computed as the difference between the absolute risk in the control group (ARC) and the absolute risk in the treatment group (ART).Since Warfarin is the standard of treatment, Warfarin is considered as the control group.ARR = ARC-ARTARR = (20/500) – (30/300)ARR = -0.06This means that there is increased risk of stroke in the treatment group, which is the Ticagrelor group.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 91
Correct
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In the treatment of hypertensive episodes in pheochromocytoma, which of the following medication types is administered as first-line management:
Your Answer: Alpha-blockers
Explanation:The first line of management in controlling blood pressure and preventing intraoperative hypertensive crises is to use a combination of alpha and beta-adrenergic inhibition. In phaeochromocytoma, alpha-blockers are used to treat hypertensive episodes in the short term. Tachycardia can be managed by the careful addition of a beta-blocker, preferably a cardioselective beta-blocker, once alpha blockade has been established. Long term management of pheochromocytoma involves surgery.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 92
Correct
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Which of the following is NOT a typical clinical feature of beta-thalassaemia major:
Your Answer: Increased bleeding tendency
Explanation:Features include:- severe anaemia (becoming apparent at 3 – 6 months when the switch from gamma-chain to beta-chain production takes place)- failure to thrive- hepatosplenomegaly (due to excessive red cell destruction, extramedullary haemopoiesis and later due to transfusion related iron overload)- expansion of bones (due to marrow hyperplasia, resulting in bossing of the skull and cortical thinning with tendency to fracture)- increased susceptibility to infections (due to anaemia, iron overload, transfusion and splenectomy)- osteoporosis- hyperbilirubinaemia and gallstones- hyperuricaemia and gout- other features of haemolytic anaemia- liver damage and other features of iron overload
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This question is part of the following fields:
- Haematology
- Pathology
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Question 93
Correct
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On his stool culture, a patient with a diarrhoeal illness grows Escherichia coli.What SINGLE statement about Escherichia coli is true?
Your Answer: Most serotypes are harmless
Explanation:Escherichia coli is a Gram-negative, non-spore forming, facultative anaerobic, rod-shaped bacterium. Although some can cause serious food poisoning, most serotypes are harmless.Escherichia coli is transmitted via the faeco-oral route.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 94
Correct
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Na+ is reabsorbed via the Na+/K+/2Cl-symporter in which part of the loop of Henle?
Your Answer: Thick ascending limb
Explanation:In the thick ascending limb is the part of the loop of Henle in which there is active reabsorption of Na+and Cl- ions from the tubular fluid. This occurs via the Na+/K+/2Cl-symporter on the apical membrane. This mechanism is by:1. Na+ions are transported across the basolateral membrane by Na+pumps and the Cl-ions by diffusion. 2. K+leaks back into the tubular fluid via apical ROMK K+channels which creates a positive charge. 3. This positive charge drives the reabsorption of cations (Na+, K+, Ca2+, Mg2+) through paracellular pathways. 4. Due to the thick ascending limb being impermeable to water, the tubular fluid osmolality is reduced by ion reabsorption, the interstitial fluid osmolality is increased, and an osmotic difference is created.
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This question is part of the following fields:
- Physiology
- Renal
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Question 95
Incorrect
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Regarding gas exchange at the alveolar-capillary membrane, which of the following statements is CORRECT:
Your Answer: The rate of diffusion across the membrane is governed by Darcy's law.
Correct Answer: The rate of diffusion in lungs can be estimated by measuring the diffusing capacity of the lungs for carbon monoxide.
Explanation:Gas exchange between alveolar air and blood in the pulmonary capillaries takes place by diffusion across the alveolar-capillary membrane. Diffusion occurs from an area of high partial pressure to an area of low partial pressure, thus the driving force for diffusion is the alveolar-capillary partial pressure gradient. Diffusion occurs across a membrane and is therefore governed by Fick’s law. Although CO2is larger than O2, it is is much more soluble and diffuses 20 times more rapidly. The diffusing capacity for oxygen (DLO2) cannot be measured directly but the rate of diffusion in the lungs can be estimated by measuring the diffusing capacity of the lungs for carbon monoxide (DLCO).
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 96
Correct
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Which one of these equations best defines lung compliance?
Your Answer: Change in volume / change in pressure
Explanation:Lung compliance is defined as change in volume per unit change in distending pressure. Lung compliance is calculated using the equation:Lung compliance = ΔV / ΔPWhere:ΔV is the change in volumeΔP is the change in pleural pressure.Static compliance is lung compliance in periods without gas flow, and is calculated using the equation:Static compliance = VT / Pplat − PEEPWhere:VT = tidal volumePplat = plateau pressurePEEP = positive end-expiratory pressure
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 97
Incorrect
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A 42-year-old man presented to the emergency room with complains of a dry cough and fever that has been going on for the past few days. Upon history taking and observation, it was established that he works as a Jacuzzi and whirlpool installer and smokes 15 cigarettes per day. The presence of a non-productive cough, several episodes of diarrhoea, developed bilateral pleuritic chest pain, and shortness of breath most notably on exertion were also noted.Which of the following is most likely the causative agent of the case presented above?
Your Answer: Legionella longbeachae
Correct Answer: Legionella pneumophila
Explanation:Legionella species are ubiquitous, Gram-negative bacilli acquired primarily through inhalation. Infections caused by Legionella spp. produce a spectrum of symptoms ranging from mild upper respiratory tract infections to pneumonia. Legionella spp. are responsible for 2% to 15% of community-acquired pneumonia.Clinical manifestations of Legionella infections include febrile disease with pneumonia (legionnaires’ disease), febrile disease without pulmonary involvement (Pontiac fever), and asymptomatic infection.The mode of transmission and the number of infecting organisms in the inoculum play a role in the clinical features of the infection. In addition, host factors, such as a suppressed immune system, chronic lung disease, alcoholism, and heavy smoking, predispose individuals to legionnaires’ disease.Legionella spp. can tolerate chlorine concentrations of 3 mg/L, they resist water treatment and subsequently gain entry into and colonize human-made water supplies and distribution systems. Hot water systems, cooling towers, and evaporative condensers are major reservoirs. Other sources include cold water systems, ornamental fountains, whirlpool spas, humidifiers, respiratorytherapy equipment, and industrial process waters.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 98
Correct
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A 20-year-old female presents with painful wrist following a fall while skating. X-rays shows fracture of the ulna.The initial phase of bone healing is?
Your Answer: Haematoma at the fracture site
Explanation:Haemorrhage occurs into the fracture site from the ruptured vessels in the bone marrow and those supplying the periosteum immediately after fracture. This hematoma formation is the first phase of bone healing.The 4 stages of bone healing are:Haematoma at the fracture site (provides a framework for healing)Callus formationLamellar bone formationRemodelling
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 99
Incorrect
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A 66-year-old female with a history of stroke one year ago presents to the Family Medicine clinic complaining of fatigue, weight loss, and tongue discolouration. On examination, she seems malnourished, her tongue is beefy red, and an ataxic gait pattern is noticed. Which ONE of the following conditions does this patient most likely have?
Your Answer: Folic acid deficiency
Correct Answer: Vitamin B12 deficiency
Explanation:A history of stroke and poor nutritional status points towards a nutritional deficiency as the most likely cause of her symptoms. The examination would differentiate between Vitamin B12 and Folic acid deficiency as in the former. The patient has a beefy red tongue and symptoms indicating peripheral nervous system involvement or subacute combined spinal cord degeneration. The patient may also have a lemon-yellow skin colour, loss of proprioception and vibratory sense and oral ulceration. Investigations in B12 deficiency can reveal the following:1. Macrocytic anaemia2. Neutropoenia3. Thrombocytopaenia4. Blood film: anisocytosis, poikilocytosis5. Low serum B126. Raised serum bilirubin (haemolysis)7. Intrinsic factor antibodies8. Positive Schilling test
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This question is part of the following fields:
- Haematology
- Pathology
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Question 100
Incorrect
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You are asked to review the blood results on a 56-year-old man who appears to be acutely unwell. His results show that he is neutropenic.Which ONE of the following is NOT a recognized cause of a neutropenia?
Your Answer: Viral infections
Correct Answer: Hyposplenism
Explanation:Neutropenia is defined as a total neutrophil count of < 2.0 x 109/l.It can be caused by:Viral infectionsCollagen disease e.g. SLE and RAChemotherapy and radiotherapyHypersplenismMarrow infiltrationVitamin and folate deficiencyDrug reactionsDrugs that cause neutropenia include flecainide, phenytoin, carbimazole, indomethacin and co-trimoxazole.
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This question is part of the following fields:
- Haematology
- Pathology
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