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Question 1
Incorrect
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Metabolic hyperaemia harmonizes local blood flow with local O2 demand. If there is an increase in metabolic rate, the production of vasoactive metabolites increases. These metabolites act locally on the surrounding arterioles, causes vasodilation and an increase blood supply.Which of these metabolites is the most potent vasodilator in skeletal muscle?
Your Answer: H 2 O 2
Correct Answer: K +
Explanation:Hyperaemia is the process where the body adjusts blood flow to meet the metabolic needs of different tissues in health and disease. Vasoactive mediators that take part in this process include K+, adenosine, CO2, H+, phosphates and H2O2. Although the mechanism is not clear, all these mediators likely contribute to some extent at different points.Specific organs are more sensitive to specific metabolites:K+ and adenosine are the most potent vasodilators in skeletal musclesCO2 and K+ are the most potent vasodilators in cerebral circulation.
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This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
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Question 2
Correct
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When a child has chickenpox, how long should he or she be off from school?
Your Answer: Until all vesicles have crusted over
Explanation:To avoid the spread of infection, infected patients should be isolated. All lesions should be crusted over before children return to nursery or school, even if the standard exclusion time is 5 days.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 3
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 4
Incorrect
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Despite taking the oral contraceptive pill, a 29-year-old woman becomes pregnant. During a medication review, you discover that she is epileptic and that her antiepileptic therapy has recently been changed.Which of the following antiepileptics is most likely to impair the oral contraceptive pill's effectiveness?
Your Answer: Sodium valproate
Correct Answer: Carbamazepine
Explanation:The metabolism of ethinyl oestradiol and progestogens has been shown to be increased by enzyme-inducing antiepileptics. The oral contraceptive pill (OCP) is less effective in preventing pregnancy as a result of this increased breakdown.Antiepileptic drugs that induce enzymes include:CarbamazepinePhenytoinPhenobarbitalTopiramateAntiepileptics that do not induce enzymes are unlikely to affect contraception. Non-enzyme-inducing anticonvulsants include the following:ClonazepamGabapentinLevetiracetamPiracetamSodium valproate is a type of valproate that is used toLamotrigine is an antiepileptic drug that does not cause the production of enzymes. It does, however, require special consideration, unlike other non-enzyme-inducing antiepileptics. The OCP does not appear to affect epilepsy directly, but it does appear to lower lamotrigine levels in the blood. This could result in a loss of seizure control and the occurrence of seizures.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 5
Incorrect
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A 40-year-old man who has a history of asthma arrives at the emergency department complaining of palpitations that have been going on for 5 days. Which of the following beta-blockers is the safest for an asthmatic patient?
Your Answer: Sotalol
Correct Answer: Atenolol
Explanation:Atenolol is a beta blocker, which is a type of medication that works by preventing certain natural substances in the body, such as epinephrine, from acting on the heart and blood vessels. This effect reduces heart rate, blood pressure, and cardiac strain. Atenolol, bisoprolol fumarate, metoprolol tartrate, nebivolol, and (to a lesser extent) acebutolol have a lower action on beta2 (bronchial) receptors and are thus cardio selective but not cardiac specific. They have a lower effect on airway resistance, although they are not without this adverse effect.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 6
Correct
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Damage to this nerve affects the flexor digitorum longus.
Your Answer: Tibial nerve
Explanation:Like all muscles in the deep posterior compartment of the leg, flexor digitorum longus muscle is innervated by branches of the tibial nerve (root value L5, S1 and S2) which is a branch of sciatic nerve.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 7
Incorrect
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In the foetus at 4 months gestation, where does haematopoiesis mainly occur?
Your Answer: Marrow of all bones
Correct Answer: Liver and spleen
Explanation:The first place that haematopoiesis occurs in the foetus is in the yolk sac. Later on, it occurs in the liver and spleen, which are the major hematopoietic organs from about 6 weeks until 6 – 7 months gestation. At this point, the bone marrow becomes the most important site. Haemopoiesis is restricted to the bone marrow in normal childhood and adult life.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 8
Incorrect
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An arterial blood gas test is performed to a 25-year-old students who presents with confusion, headache, nausea and malaise. The results show that carbon monoxide levels are significantly high. Which of the following carbon monoxide poisoning assertions is true?
Your Answer: It has approximately 25 times the affinity for haemoglobin than oxygen does
Correct Answer: The PO 2 of the blood in CO poisoning can be normal
Explanation:By combining with haemoglobin to form carboxyhaemoglobin, carbon monoxide (CO) disrupts the blood’s oxygen transport function. CO binds to haemoglobin with a 240-fold higher affinity than oxygen. As a result, even small amounts of CO can bind a large portion of the blood’s haemoglobin, making it unavailable for oxygen transport. During a suspected carbon monoxide poisoning, the blood PO2 and haemoglobin concentrations will be normal, but the oxygen concentration will be drastically reduced. The oxygen dissociation curve will also shift to the left in the presence of Carboxyhaemoglobin ( haemoglobin and carbon monoxide combination), interfering with oxygen unloading.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 9
Correct
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Regarding paracetamol, which of the following statements is CORRECT:
Your Answer: It has anti-pyretic action.
Explanation:Paracetamol is a non-opioid analgesic, similar in efficacy to aspirin, with antipyretic properties but no anti-inflammatory properties. It is well absorbed orally and does not cause gastric irritation. Paracetamol is a suitable first-line choice for most people with mild-to-moderate pain, and for combination therapy.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 10
Incorrect
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Which of the following laboratory findings is NOT typical of von Willebrand disease (VWD):
Your Answer: Normal PT
Correct Answer: Thrombocytopaenia
Explanation:Laboratory findings typically show (although this varies depending on VWD type):Abnormal PFA-100 testLow factor VIII levels (if low a factor VIII/VWF binding assay is performed)Prolonged APTT (or normal)Normal PTLow VWF levelsDefective platelet aggregationNormal platelet count
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This question is part of the following fields:
- Haematology
- Pathology
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Question 11
Correct
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Regarding hepatitis A, which of the following statements is CORRECT:
Your Answer: Anti-HAV IgM antibodies are diagnostic.
Explanation:Anti-HAV IgM antibodies are diagnostic. Disease in children is more commonly asymptomatic, risk of symptomatic disease increases with age. Transmission is by the faecal-oral route. Faecal shedding has been demonstrated for 2 – 3 weeks before and about a week after, the onset of jaundice. Infection confers lifelong immunity.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 12
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: Obturator 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 13
Incorrect
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The cutaneous circulation's principal role is thermoregulation. This process is aided by the existence of arteriovenous anastomoses.Which of the following anatomical areas has the greatest number of arteriovenous anastomoses?Â
Your Answer: Abdomen
Correct Answer: Pinna of the ear
Explanation:Short vessels called arteriovenous anastomoses (AVAs) link tiny arteries and veins. They have a large lumen diameter. The strong and muscular walls allow AVAs to completely clog the vascular lumen, preventing blood flow from artery to vein (acting like a sphincter). When the AVAs open, they create a low-resistance connection between arteries and veins, allowing blood to flow into the limbs’ superficial venous plexuses. There is no diffusion of solutes or fluid into the interstitium due to their strong muscle walls.AVAs are densely innervated by adrenergic fibres from the hypothalamic temperature-regulation centre. High sympathetic output occurs at normal core temperatures, inducing vasoconstriction of the AVAs and blood flow through the capillary networks and deep plexuses. When the temperature rises, sympathetic output decreases, producing AVA vasodilation and blood shunting from the artery to the superficial venous plexus. Heat is lost to the environment as hot blood rushes near to the skin’s surface.AVAs are a specialized anatomical adaptation that can only be found in large quantities in the fingers, palms, soles, lips, and pinna of the ear.
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This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
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Question 14
Incorrect
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A 64-year-old woman with a history of chronic breathlessness is referred for lung function testing.Which of the following statements regarding lung function testing is FALSE? Select ONE answer only.
Your Answer: In obstructive lung disease, the FEV 1 /FVC ratio is reduced to <0.7
Correct Answer: In restrictive lung disease, the FVC is increased
Explanation:In restrictive lung disorders there is a reduction in the forced vital capacity (FVC) and the forced expiratory volume in one second (FEV1). The decline in the FVC is greater than that of the FEV1, resulting in preservation of the FEV1/FVC ratio (>0.7%).In obstructive lung disease, FEV1is reduced to <80% of normal and FVC is usually reduced but to a lesser extent than FEV1. The FEV1/FVC ratio is reduced to 80% in the presence of symptomsModerate airflow obstruction = FEV1 of 50-79%Severe airflow obstruction = FEV1 of 30-49%Very severe airflow obstruction = FEV1<30%.Spirometry is a poor predictor of durability and quality of life in COPD but can be used as part of the assessment of severity.COPD can only be diagnosed on spirometry if the FEV1 is <80% and FEV1/FVC ratio is < 0.7.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 15
Correct
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A 71-year-old man treated with antibiotics for a chest infection returns with a profuse, offensive smelling diarrhoea. A diagnosis of Clostridium difficile diarrhoea is made after investigations.Which antibiotic is associated with the greatest risk of causing Clostridium Difficile diarrhoea?
Your Answer: Ciprofloxacin
Explanation:Clostridium difficile, a Gram-positive, anaerobic, spore forming bacteria is present in the gut of approximately 3% of healthy adults (2012 UK HPA estimates). Following use of broad spectrum antibiotics, which alter normal gut flora, Clostridium difficile infection (CDI) occurs. About 80% of Clostridium Difficile infections are seen in people over the age of 65 and its main clinical features are:Abdominal cramps, severe bloody and/or watery diarrhoea, offensive smelling diarrhoea, and fever. CDI is the most severe consequence of antibiotic treatment and is a major cause of morbidity and mortality. Risk for CDI has been found to be greatest with clindamycin followed by fluoroquinolones Tetracyclines are not associated with risk for CDI.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 16
Incorrect
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Regarding chemical control of respiration, which of the following statements is INCORRECT:
Your Answer: A metabolic acidosis causes the relationship between PCO2 and ventilation to shift to the left.
Correct Answer: The blood-brain barrier is freely permeable to HCO3 - ions.
Explanation:CSF is separated from the blood by the blood-brain barrier. This barrier is impermeable to polar molecules such as H+and HCO3-but CO2can diffuse across it easily. The pH of CSF is therefore determined by the arterial PCO2and the CSF HCO3-and is not affected by blood pH.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 17
Incorrect
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In the Emergency Department, a 35-year-old woman actively seizing is brought in. She is quickly shifted into the resuscitation room and is administered a dose of benzodiazepine. The seizure is quickly terminated. Once the patient is stable, she tells you she is a known case of epilepsy and takes phenytoin to control it. Which of the following is the primary mechanism of action of phenytoin?
Your Answer: GABA receptor agonist
Correct Answer: Sodium channel blocker
Explanation:Phenytoin is in the anticonvulsants class of drugs and is used in the management and treatment of the following:1. epilepsy2. generalized tonic-clonic seizures3. complex partial seizures4. status epilepticus. It works by inactivating the voltage-gated sodium channels responsible for increasing the action potential. It is non-specific and targets almost all voltage-gated sodium channel subtypes. More specifically, phenytoin prevents seizures by inhibiting the positive feedback loop that results in neuronal propagation of high-frequency action potentials.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 18
Incorrect
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You are treating a patient with a Clostridium difficile infection. His condition was found to be antibiotic-associated. Which of the following pieces of advice on preventing the spread of this disease should you give this patient?
Your Answer: Prophylactic treatment with metronidazole
Correct Answer: Washing hands with soap and water
Explanation:Clostridium difficile (C. diff) can cause colitis, or inflammation of the colon. To prevent its spread, one should practice good hand hygiene, regularly clean areas of the home that may become contaminated with C. difficile, practice good hand hygiene, and clean surfaces, spills, and accidents.
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This question is part of the following fields:
- Microbiology
- Principles
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Question 19
Incorrect
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A 29-year-old woman with a skin infection not responding to first-line antibiotics return for a review clinic appointment. The result of her culture shows growth of methicillin-resistant Staphylococcus aureus (MRSA).Which among the following antibiotics is methicillin-resistant Staphylococcus aureus usually sensitive to?
Your Answer: Ceftriaxone
Correct Answer: Linezolid
Explanation:Historically, MRSA has been treated successfully with outpatient oral sulphonamides, clindamycin, rifampin, doxycycline, or a combination of these agents. With the development of increasing drug resistance of MRSA to these traditional antimicrobials, there has been a search for more effective antibiotics. One recent study demonstrated that vancomycin, linezolid, and quinupristin-dalfopristin were the most effective antibiotics against multiple strains of MRSA.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 20
Incorrect
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Amoxicillin is used first line for all of the following infections EXCEPT for:
Your Answer: Infective exacerbation of chronic bronchitis
Correct Answer: Cellulitis
Explanation:Amoxicillin is used first line for low to moderate severity community acquired pneumonia, exacerbations of chronic bronchitis, for acute otitis media, for acute sinusitis, for oral infections/dental abscess, for Listeria meningitis (in combination with another antibiotic), for infective endocarditis (in combination with another antibiotic) and for H. Pylori eradication (in combination with metronidazole/clarithromycin and a PPI). Flucloxacillin is used first line for acute cellulitis.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 21
Correct
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The functional residual capacity (FRC) will be decreased in which of the following:
Your Answer: Pulmonary fibrosis
Explanation:Factors decreasing FRC:Restrictive ventilatory defects e.g. pulmonary fibrosisPosture – lying supineIncreased intra-abdominal pressure (e.g. obesity, pregnancy, ascites)Reduced muscle tone of diaphragm e.g. muscle relaxants in anaesthesia, neuromuscular disease
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 22
Correct
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Gastrin primarily acts to perform which of the following functions:
Your 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 23
Incorrect
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A patient suffers a stab wound to the neck. The entry point of the blade is situated within the anterior triangle of the neck.Which of the following muscles is most likely to be involved? Select ONE answer only.
Your Answer: Sternocleidomastoid
Correct Answer: Sternothyroid
Explanation:The anterior triangle is the triangular area of the neck found anteriorly to the sternocleidomastoid muscle. It is formed by the anterior border of sternocleidomastoid laterally, the median line of the neck medially and by the inferior border of the mandible superiorly. The apex of the anterior triangle extends towards the manubrium sterni. The anterior triangle contains:Muscles: thyrohyoid, sternothyroid, sternohyoid musclesOrgans: thyroid gland, parathyroid glands, larynx, trachea, esophagus, submandibular gland, caudal part of the parotid glandArteries: superior and inferior thyroid, common carotid, external carotid, internal carotid artery (and sinus), facial, submental, lingual arteriesVeins: anterior jugular veins, internal jugular, common facial, lingual, superior thyroid, middle thyroid veins, facial vein, submental vein, lingual veinsNerves: vagus nerve (CN X), hypoglossal nerve (CN XII), part of sympathetic trunk, mylohyoid nerveThe posterior triangle is a triangular area found posteriorly to the sternocleidomastoid muscle. It has three borders; anterior, posterior and inferior borders. The anterior border is the posterior margin of the sternocleidomastoid muscle. The posterior border is the anterior margin of the trapezius muscle, while the inferior border is the middle one-third of the clavicle. The investing layer of deep cervical fascia and integument forms the roof of the space, while the floor is covered with the prevertebral fascia along with levator scapulae, splenius capitis and the scalene muscles. The inferior belly of omohyoid subdivides the posterior triangle into a small supraclavicular, and a large occipital, triangle.Contents:Vessels: the third part of the subclavian artery, suprascapular and transverse cervical branches of the thyrocervical trunk, external jugular vein, lymph nodesNerves: accessory nerve (CN XI), the trunks of the brachial plexus, fibers of the cervical plexus
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 24
Correct
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Which of the following is NOT a benefit of low molecular weight heparin (LMWH) over unfractionated heparin therapy:
Your Answer: Its effects can be rapidly and completely reversed with protamine sulfate.
Explanation:Advantages of LMWHGreater ability to inhibit factor Xa directly, interacting less with platelets and so may have a lesser tendency to cause bleedingGreater bioavailability and longer half-life in plasma making once daily subcutaneous administration possibleMore predictable dose response avoiding the need for routine anticoagulant monitoringLower associated risk of heparin-induced thrombocytopenia or of osteoporosis
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 25
Incorrect
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A 68-year-old man with BPH presents to the emergency department in significant pain secondary to urinary retention. What is the location of the neuronal cell bodies that are responsible for urinary bladder discomfort sensation?
Your Answer: Dorsal root ganglia of spinal cord levels L1 - L4
Correct Answer: Dorsal root ganglia of spinal cord levels S2, S3 and S4
Explanation:The activation of stretch receptors with visceral afferents relayed through the pelvic nerve plexus and into the pelvic splanchnic nerves causes bladder pain. The sensory fibres of spinal nerves S2 – S4 enter the dorsal root ganglia.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 26
Correct
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A 72-year-old man presents with chest pain that is characteristic of angina. You administer a dose of glyceryl trinitrate (GTN), which rapidly resolved his symptoms. Unfortunately, he also develops an unpleasant side effect.Which of the following side effects is he most likely to have developed? Select ONE answer only.
Your Answer: Headache
Explanation:Nitrates are used in the treatment of angina pectoris and the prevention of myocardial ischaemia. Commonly used examples of nitrates are glyceryl trinitrate and isosorbide dinitrate. Unwanted effects, however, are common and can limit therapy, particularly when angina is severe or when patients are unusually sensitive to the effects of nitrates.The following are common or very common side effects of nitratesArrhythmiasAstheniaCerebral ischaemiaDizzinessDrowsinessFlushingHeadacheHypotensionNausea and vomitingDiarrhoea, syncope and cyanosis can occur, but these are rare side effects. Dry eyes, bradycardia and metabolic acidosis have not been reported.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 27
Incorrect
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Regarding iron handling, which of the following statements is CORRECT:
Your Answer: Ascorbic acid inhibits the reduction of ferric (Fe 3+ ) to ferrous (Fe 2+ ) iron.
Correct Answer: Iron is taken across the enterocyte apical membrane by the divalent metal transporter (DMT1).
Explanation:Dietary iron may be in the form of haem or non-haem iron. Haem iron is degraded after absorption through the cell surface to release Fe2+. Most non-haem iron is in the form Fe3+, which is reduced at the luminal surface to the more soluble Fe2+, facilitated by hydrochloric acid in gastric secretions (and enhanced by ascorbic acid). Fe2+is taken across the enterocyte apical membrane by the divalent metal transporter (DMT1). In the enterocyte, Fe2+is then either stored in enterocyte epithelial cells as ferritin, or released into portal plasma via the molecule ferroportin at the basolateral membrane.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 28
Correct
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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 29
Incorrect
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Depression of the eyeball is primarily produced by which of the following muscles:
Your Answer: Superior rectus and superior oblique
Correct Answer: Inferior rectus and superior oblique
Explanation:Depression of the eyeball is produced by the inferior rectus and the superior oblique muscles.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 30
Incorrect
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Atracurium is used as a muscle relaxant during endotracheal intubation. This drug’s mechanism of action is best described by which of the following?
Your Answer: GABA receptor antagonist
Correct Answer: Nicotinic acetylcholine receptor antagonist
Explanation:Atracurium is a non-depolarizing neuromuscular blocker that is used to help with intubation and controlled ventilation by causing muscle relaxation and paralysis. At the neuromuscular junction’s post-synaptic membrane, atracurium competes with acetylcholine for nicotinic (N2) receptor binding sites. This prevents the receptors from being stimulated by acetylcholine. Muscle paralysis occurs gradually due to the competitive blockade.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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SESSION STATS - PERFORMANCE PER SPECIALTY
