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Question 1
Correct
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A 25-year-old footballer develops pain and stiffness in his thigh. A diagnosis of iliopsoas syndrome is made.Iliacus is innervated by which of the following nerves? Select ONE answer only.
Your Answer: Femoral nerve
Explanation:Iliacus is innervated by the femoral nerve.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 2
Incorrect
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Which of the following statements regarding the pituitary gland is CORRECT:
Your Answer: Oxytocin release from the posterior pituitary is controlled primarily by negative feedback mechanisms.
Correct Answer: Cortisol inhibits release of adrenocorticotropic hormone (ACTH) from the anterior pituitary.
Explanation:Anterior pituitary hormones are released under the control of hypothalamic releasing or inhibiting hormones originating from small neurons with their cell bodies in the hypothalamus and released into the blood at the median eminence. These hypothalamic hormones are transported directly to the anterior pituitary via hypophyseal portal vessels. The anterior pituitary hormones (and the hormones released by their target organs) inhibit further release of hypothalamic and anterior pituitary hormones by negative feedback mechanisms e.g. cortisol inhibits the release of ACTH. Prolactin release from the anterior pituitary is inhibited by dopamine.The posterior pituitary is really a direct extension of the hypothalamus. Oxytocin and ADH are manufactured in the cell bodies of large neurons in the hypothalamus and are transported down the axons of these cells to their terminals on capillaries originating from the inferior hypophyseal artery within the posterior pituitary gland. ADH release is controlled by negative feedback mechanisms based on plasma osmolality and blood volume, oxytocin however is involved in positive feedback mechanisms.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 3
Correct
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Which lobe of the prostate gland is most commonly affected in benign prostatic hypertrophy?
Your Answer: Median
Explanation:Benign enlargement of the prostate is common in men older than 50 years. The cause is possibly an imbalance in the hormonal control of the gland. The median lobe of the gland enlarges upward and encroaches within the sphincter vesicae, located at the neck of the bladder. The leakage of urine into the prostatic urethra causes an intense reflex desire to micturate. The enlargement of the median and lateral lobes of the gland produces elongation and lateral compression and distortion of the urethra so that the patient experiences difficulty in passing urine and the stream is weak. Back-pressure effects on the ureters and both kidneys are a common complication. The enlargement of the uvula vesicae (owing to the enlarged median lobe) results in the formation of a pouch of stagnant urine behind the urethral orifice within the bladder. The stagnant urine frequently becomes infected, and the inflamed bladder (cystitis) adds to the patient’s symptoms.In all operations on the prostate, the surgeon regards the prostatic venous plexus with respect. The veins have thin walls, are valveless, and are drained by several large trunks directly into the internal iliac veins. Damage to these veins can result in a severe haemorrhage.
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This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 4
Incorrect
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A 22-year-old with a history of brittle asthma is brought to the ED by her partner. She is wheezing and very short of breath and her condition is deteriorating rapidly. Following a series of nebulisations, hydrocortisone and IV magnesium sulphate, she is taken to resus and the intensive care team is called to review her. She is severely hypoxic and confused and a decision is made to intubate her.Which of these drugs is ideal as an induction agent in this patient?
Your Answer: Thiopental sodium
Correct Answer: Ketamine
Explanation:Only about 2% of asthma attacks requires intubation and most severe cases are managed with non-invasive ventilation techniques.Though life-saving in the crashing asthmatic, intubation in asthmatic patients is associated with significant morbidity and mortality and is risky. Indications for intubation in asthmatic patients include:Severe hypoxiaAltered mental stateRespiratory or cardiac arrestFailure to respond to medicationsKetamine (1-2 mg/kg) is the preferred induction agent. It has bronchodilatory properties and does not cause hypotension. Propofol poses a risk of hypotension but can also be used.
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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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In the United Kingdom, which of the following is the most often used intravenous aesthetic:
Your Answer: Propofol
Explanation:In the United Kingdom, propofol is the most widely used intravenous anaesthetic. In adults and children, it can be used to induce or maintain anaesthesia, although it is not commonly used in newborns. It can also be used to sedate individuals in intensive care and for sedation during operations.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 6
Correct
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Which of the following causes type 1 diabetes mellitus?
Your Answer: Autoimmune destruction of beta-cells results in insulin deficiency
Explanation:Type 1 diabetes mellitus results from autoimmune destruction of the insulin-producing beta cells in the islets of Langerhans. This process occurs in genetically susceptible subjects, is probably triggered by one or more environmental agents, and usually progresses over many months or years during which the subject is asymptomatic and euglycemic.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 7
Correct
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If a patient dislocated his right shoulder and has been referred to the orthopaedic outpatient department for a follow-up after a successful reduction, which of the following is the most important position for him to avoid holding his arm in until he is seen in the clinic?
Your Answer: Arm at 90 degrees to side with palm up
Explanation:The arm should be placed in a poly-sling that should be worn for about two weeks. A physiotherapist may give gentle movements for the arm to help in reducing stiffness and in relieving the pain. It is important that the patient must avoid positions that could cause re-dislocation.The most important position to avoid is the arm being held out at 90 degrees to the side with the palm facing upwards, especially if a force is being applied.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 8
Correct
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Compression of this nerve can cause weakness in the left leg while walking and thigh adduction weakness at the hip joint.
Your Answer: Obturator nerve
Explanation:The obturator nerve is a sensory and motor nerve that emerges from the lumbar plexus and innervates the thigh. This nerve supplies motor innervation to the medial compartment of the thigh, making it necessary for thigh adduction.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 9
Incorrect
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Which of the following statements regarding forest plots is true? Select ONE answer only.Which of the following statements regarding forest plots is true? Select ONE answer only.
Your Answer: The length of the horizontal lines emerging from the squares represents the standard deviation
Correct Answer: Larger studies are associated with smaller horizontal lines
Explanation:Forest plots are graphical displays designed to illustrate the relative strength of treatment effects in multiple individual studies addressing the same question.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 10
Incorrect
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A 16-year-old male with a known case of Haemophilia A is referred to your orthopaedic clinic for evaluation and aspiration of a hemarthrosis of the left knee joint. Out of the modes of inheritance listed below, which one is present in this disease?
Your Answer: X-linked dominant
Correct Answer: X-linked recessive
Explanation:All the Haemophilia’s have an X-linked recessive inheritance pattern, so they only manifest in male patients. Diseases with a mitochondrial inheritance pattern include MELAS syndrome, Leigh syndrome, LHON and MERRF syndrome. Autosomal dominant disorders include Huntingdon disease and Marfan syndrome. X-linked dominant diseases include Fragile X syndrome. Autosomal recessive diseases include cystic fibrosis and sickle cell disease.
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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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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 12
Correct
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A 29-year-old female with chronic anaemia secondary to sickle cell disease is being transfused. A few minutes after starting the blood transfusion, she develops widespread itching with urticarial rash, wheezing, nausea and chest pain. Her BP reduces to 60/40 mmHg.What is the most appropriate treatment?
Your Answer: Stop the transfusion and administer adrenaline
Explanation:Anaphylaxis transfusion reaction occurs when an individual has previously been sensitized to an allergen present in the blood and, on re-exposure, releases IgE or IgG antibodies. Patients with anaphylaxis usually develop laryngospasm, bronchospasm, abdominal pain, nausea, vomiting, hypotension, shock, and loss of consciousness. The transfusion should be stopped immediately and the patient should be treated with adrenaline, oxygen, corticosteroids, and antihistamines.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 13
Correct
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A 36-year-old man presented to the emergency room with a two-week history of shortness of breath, fevers, and malaise. A chest X-ray was ordered and the results confirmed the diagnosis of a right middle lobe pneumonia. Which of the following structures of the heart lies closest to the consolidation?
Your Answer: Right atrium
Explanation:In its typical anatomical orientation, the heart has 5 surfaces formed by different internal divisions of the heart:Anterior (or sternocostal) – Right ventriclePosterior (or base) – Left atriumInferior (or diaphragmatic) – Left and right ventriclesRight pulmonary – Right atriumLeft pulmonary – Left ventricleThe silhouette sign of Felson is with respect to the right middle lobe. The right heart border should have a distinct appearance due to the right atrium abutting aerated right middle lobe. The consolidation in the right middle lobe has resulted in loss of this silhouette.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 14
Incorrect
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The syndrome of inappropriate antidiuresis due to excessive antidiuretic hormone (ADH) secretion is diagnosed in a male patient with a history of recurrent hyponatraemia.Which of the following produces ADH?
Your Answer: Posterior pituitary
Correct Answer: Hypothalamus
Explanation:Antidiuretic hormone (ADH), commonly known as vasopressin, is a peptide hormone that controls how much water the body retains.It is produced in the magnocellular and parvocellular neurosecretory cells of the paraventricular nucleus and supraoptic nucleus in the hypothalamus from a prohormone precursor. It is subsequently carried to the posterior pituitary via axons and stored in vesicles.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.Stretch receptors in the atrial walls and big veins detect a decrease in atrial pressure as a result of this (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.The main sites of action for ADH are:The kidney is made up of two parts. ADH’s main job is to keep the extracellular fluid volume under control. It increases permeability to water by acting on the renal collecting ducts via V2 Receptors (via a camp-dependent mechanism). This leads to a decrease in urine production, an increase in blood volume, and an increase in arterial pressure as a result.Vascular system: Vasoconstriction is a secondary function of ADH. ADH causes vasoconstriction via binding to V1 Receptors on vascular smooth muscle (via the IP3 signal transduction pathway). An increase in arterial pressure occurs as a result of this.
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 15
Correct
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In which part of the gastrointestinal tract is Meckel's diverticulum commonly located?
Your Answer: Ileum
Explanation:Meckel’s diverticulum is the most prevalent congenital anomaly of the gastrointestinal tract, affecting approximately 2% of the general population. Meckel’s diverticulum are designated true diverticula because their walls contain all the layers found in normal small intestine. Their location varies among individual patients, but they are usually found in the ileum within 100 cm of the ileocecal valve.Approximately 60% of Meckel’s diverticulum contain heterotopic mucosa, of which over 60% consist of gastric mucosa. Pancreatic acini are the next most common; others include Brunner’s glands, pancreatic islets, colonic mucosa, endometriosis, and hepatobiliary tissues.A useful, although crude, mnemonic describing Meckel’s diverticulum is the “rule of twos”: 2% prevalence, 2:1 male predominance, location 2 feet proximal to the ileocecal valve in adults, and half of those who are symptomatic are under 2 years of age.
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This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 16
Incorrect
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Regarding calcium channel blockers, which of the following statements is CORRECT:
Your Answer: Verapamil is the calcium channel blocker of choice post-myocardial infarction in patients with heart failure.
Correct Answer: Calcium channel blockers inhibit L-type voltage-sensitive calcium channels in arterial smooth muscle causing vasodilation.
Explanation:Calcium channel blockers inhibit L-type voltage-sensitive calcium channels in arterial smooth muscle, causing relaxation and vasodilation (reduction in peripheral vascular resistance). They also block calcium channels within the myocardium and conducting tissues of the heart which produces a negative inotropic effect by reducing calcium influx during the plateau phase of the action potential. They have a variety of uses, including:HypertensionAnginaAtrial fibrillationMigraineCalcium channel blockers have been found to be moderately useful in the prevention of migraines. The best evidence is for this is with verapamil. This may be due to the prevention of the arteriolar constriction that is associated with migraine. They are commonly used for this elsewhere in the world but are not currently licensed for this use in the UK.The following are common side effects of all calcium-channel blockers:Abdominal painDizzinessDrowsinessFlushingHeadacheNausea and vomitingPalpitationsPeripheral oedemaSkin reactionsTachycardiaVerapamil is highly negatively inotropic and reduces cardiac output, slows the heart rate and may impair atrioventricular conduction. It may precipitate heart failure, exacerbate conduction disorders, and cause hypotension at high doses and should not be used with beta-blockers. Nifedipine has less myocardial effects than verapamil and has no antiarrhythmic properties but has more influence on the vessels. Nimodipine is used solely for the prevention and treatment of vascular spasm following aneurysmal subarachnoid haemorrhage.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 17
Correct
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A 25-year-old patient requires procedural sedation for reduction of an open fracture of his tibia and fibula. You plan on using ketamine as the sedative agent.Ketamine works as a result of action on what type of receptor? Select ONE answer only.
Your Answer: N-methyl-D-aspartate (NMDA)
Explanation:Ketamine is the only anaesthetic agent available that has analgesic, hypnotic, and amnesic properties. When used correctly it is a very useful and versatile drug.Ketamine acts by non-competitive antagonism of the NMDA receptor Ca2+ channel pore and also inhibits NMDA receptor activity by interaction with the phencyclidine binding site.Ketamine can be used intravenously and intramuscularly. The intramuscular dose is 10 mg/kg, and when used by this route, it acts within 2-8 minutes and has a duration of action of 10-20 minutes. The intravenous dose is 1.5-2 mg/kg administered over a period of 60 seconds. When used intravenously, it acts within 30 seconds and has a duration of action of 5-10 minutes. Ketamine is also effective when administered orally, rectally, and nasally.Ketamine causes tachycardia, an increase in blood pressure, central venous pressure, and cardiac output, secondary to an increase in sympathetic tone. Baroreceptor function is well maintained, and arrhythmias are uncommon.The main disadvantage to the use of ketamine is the high incidence of hallucinations, nightmares, and other transient psychotic effects. These can be reduced by the co-administration of a benzodiazepine, such as diazepam or midazolam.The main side effects of ketamine are:Nausea and vomitingHypertensionNystagmusDiplopiaRash
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 18
Correct
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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: 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 19
Correct
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A patient presents with epistaxis. She tells you that she has a rare platelet disorder and gives you her haematology outpatient letter that contains information about it. You learn that her disorder is caused by low levels of glycoprotein IIb/IIIa.What is the SINGLE most likely diagnosis?
Your Answer: Glanzamann’s thromboasthenia
Explanation:Glanzmann’s thromboasthenia is a rare platelet disorder in which platelets contain defective or low levels of glycoprotein IIb/IIIa.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 20
Correct
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A blood transfusion is given to a 52-year-old woman. She develops chills and rigours shortly after the transfusion begins. The following are her observations: Temperature 40°C, HR 116 bpm, BP 80/48, SaO 2 97 percent on air.Which of the following treatments is the most appropriate?
Your Answer: Stop the transfusion and administer antibiotics
Explanation:Bacterial infections are common in the following situations:Platelet transfusions are associated with a higher risk of bacterial infection (as platelets are stored at room temperature)Immersion in a water bath thawed previously frozen components.Components of red blood cells that have been stored for several weeksGram-positive and Gram-negative bacteria have both been linked to transfusion-transmitted bacterial infection, but Gram-negative bacteria are linked to a higher rate of morbidity and mortality.Yersinia enterocolitica is the most common bacterial organism linked to transfusion-transmitted bacterial infection. This organism can multiply at low temperatures while also utilising iron as a nutrient. As a result, it’s well-suited to proliferating in blood banks.The following are some of the most common clinical signs and symptoms of a bacterial infection transmitted through a blood transfusion. These symptoms usually appear shortly after the transfusion begins:Fever is very high.Rigours and chillsVomiting and nauseaTachycardiaHypotensionCollapse of the circulatory systemIf a bacterial infection from a transfusion is suspected, the transfusion should be stopped right away. Blood cultures and a Gram stain should be requested, as well as broad-spectrum antibiotics. In addition, the blood pack should be returned to the blood bank for an urgent culture and Gram-stain.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 21
Incorrect
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Regarding likelihood ratios, which of the following statements is INCORRECT:
Your Answer: A test with a low negative likelihood ratio is good at increasing certainty about the absence of a disorder.
Correct Answer: Likelihood ratios, like predictive values, are affected by the prevalence of the disease in the population.
Explanation:A likelihood ratio is a measure of the diagnostic value of a test. Likelihood ratios show how many times more likely patients with a disease are to have a particular test result than patients without the disease. Likelihood ratios are more useful than predictive values because they are calculated from sensitivity and specificity and therefore remain constant even when the prevalence of the disorder changes.
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 22
Incorrect
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Which of the following best describes the positive predictive value of a diagnostic test:
Your Answer: The ratio of the chance of a positive result if the patient has the disease to the chance of a positive result if they do not have the disease
Correct Answer: The proportion of individuals with a positive test result who have the disease
Explanation:Positive predictive value (PPV) is the proportion of individuals with a positive test result who actually have the disease.PPV = a/(a+b)
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 23
Correct
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A CT pulmonary angiography of a patient with a massive pulmonary embolus will most likely show which of the following signs?
Your Answer: Increased alveolar dead space
Explanation:A CT pulmonary angiogram is an angiogram of the blood vessels of the lungs. It is a diagnostic imaging test used to check for pulmonary embolism. A pulmonary embolism is caused by a blood clot or thrombus that has become lodged in an artery in the lung and blocks blood flow to the lung. A patient with pulmonary embolism may feel an abrupt onset of pleuritic chest pain, shortness of breath, and hypoxia. Also, pulmonary embolism can result in alveolar dead space. Dead space represents the volume of ventilated air that does not participate in gas exchange. The alveolar dead space is caused by ventilation/perfusion imbalances in the alveoli. It is defined as the sum of the volumes of alveoli that are ventilated but not perfused. Aside from pulmonary embolism, smoking, bronchitis, emphysema, and asthma are among the other causes of alveolar dead space. The other types of dead space are the following: Anatomical dead space is the portion of the airways that conducts gas to the alveoli. This is usually around 150 mL, and there is no possibility of gas exchange in these areas. Physiological dead space is the sum of anatomical and alveolar dead spaces. Physiological dead space can account for up to 30% of the tidal volume.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 24
Incorrect
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Regarding water and electrolyte absorption in the small intestine, which of the following statements is INCORRECT:
Your Answer: K+ leaves the cell across the basolateral membrane down its concentration gradient linked to an outward movement of Cl-.
Correct Answer: Na+ enters the cell across the apical membrane against its concentration gradient by both membrane channels and transporter protein mechanisms.
Explanation:As the contents of the intestine are isotonic with body fluids and mostly have the same concentration of the major electrolytes, their absorption is active. Water cannot be moved directly, but follows osmotic gradients set up by the transport of ions, primarily mediated by the sodium pump.Na+/K+ ATPase located on the basolateral membrane of the epithelial cells pumps three Na+ ions from the cell in exchange for two K+ ions, against their respective concentration gradients. This leads to a low intracellular concentration of Na+ and a high intracellular concentration of K+. The low intracellular concentration of Na+ ensures a movement of Na+ from the intestinal contents into the cell down its concentration gradient by both membrane channels and transporter protein mechanisms. Na+ is then rapidly pumped again by the basolateral sodium pump. K+ leaves the cell across the basolateral membrane down its concentration gradient linked to an outward movement of Cl- against its concentration gradient (Cl- having entered the cell across the luminal membrane down its concentration gradient).
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 25
Incorrect
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Which of the following is a contraindication to using nitrous oxide:
Your Answer: Third degree heart block
Correct Answer: Raised intracranial pressure
Explanation:Nitrous oxide should not be utilized in patients with an air-containing confined area because it diffuses into these spaces, causing a rise in pressure. This includes circumstances like pneumothorax, intracranial air after a head injury, imprisoned air from a recent undersea dive, a recent intraocular gas injection, or intestinal blockage. Nitrous oxide increases cerebral blood flow and should be avoided in individuals who have or are at risk of having high intracranial pressure.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 26
Correct
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Which of the following is NOT a typical effect caused by adrenaline:
Your Answer: Bronchoconstriction
Explanation:Actions of adrenaline:Cardiovascular system- Increased rate and force of cardiac contraction- Vasoconstriction of vessels in skin, mucous membranes and splanchnic bed- Vasodilation of skeletal muscle vessels- Increased cardiac output and blood pressureRespiratory system- Bronchodilation- Increased ventilation rateGastrointestinal system- Smooth muscle relaxation- Contraction of sphincters- Metabolism- Decreased insulin release- Increased glucagon release- Increased thermogenesis- Increased glycolysis- Increased lipolysisEye- Pupillary dilation
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 27
Incorrect
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Which of the following nerves supplies the abductor pollicis brevis?
Your Answer: The radial nerve
Correct Answer: The recurrent branch of the median nerve
Explanation:Abductor pollicis brevis is innervated by the recurrent (thenar) branch of median nerve (root value C8 and T1).
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 28
Incorrect
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A 70-year-old man presents with right-sided hemiplegia and loss of joint position sense, vibratory sense, and discriminatory touch. Upon further physical examination, it was observed that her tongue deviates to the left-hand side. An MRI and CT scan was ordered and results showed that he was suffering a left-sided stroke. Branches of which of the following arteries are most likely implicated in the case?
Your Answer: Posterior inferior cerebellar artery
Correct Answer: Anterior spinal artery
Explanation:Medial medullary syndrome is a form of stroke that affects the medial medulla of the brain. It is caused by a lesion in the medial part of the medulla, which is due to an infraction of vertebral arteries and/or paramedian branches of the anterior spinal artery.It is characterized by contralateral paralysis of the upper and lower limb of the body, a contralateral decrease in proprioception, vibration, and/or fine touch sensation, paresthesias or less commonly dysesthesias in the contralateral trunk and lower limb, and loss of position and vibration sense with proprioceptive dysfunction. Ipsilateral deviation of the tongue due to ipsilateral hypoglossal nerve damage can also be seen.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 29
Correct
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Needle thoracentesis in a patient with tension pneumothorax is performed at which anatomical landmark?
Your Answer: 4-5th intercostal space mid-axillary line
Explanation:Pleural aspiration describes a procedure whereby pleural fluid or air may be aspirated via a system inserted temporarily into the pleural space. This may be for diagnostic purposes (usually removing 20–50 ml fluid) or therapeutic to relieve symptoms. In the literature it is varyingly called thoracocentesis, thoracentesis or pleural aspiration.
Cadaver studies have shown improved success in reaching the thoracic cavity when the fourth or fifth intercostal space mid-axillary line is used instead of the second intercostal space mid-clavicular line in adult patients. ATLS now recommends this location for needle decompression in adult patients.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 30
Incorrect
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Which of the following is a primary action of calcitonin:
Your Answer: Inhibition of PTH secretion from the parathyroid glands
Correct Answer: Decreased bone resorption through inhibition of osteoclast activity
Explanation:Calcitonin is a 32 amino acid polypeptide that is primarily synthesised and released by the parafollicular cells (C-cells) of the thyroid gland in response to rising or high levels of plasma Ca2+ions. Its primary role is to reduce the plasma calcium concentration, therefore opposing the effects of parathyroid hormone.Secretion of calcitonin is stimulated by:- Increased plasma calcium concentration- Gastrin- Pentagastrin- The main actions of calcitonin are:- Inhibition of osteoclastic activity (decreasing calcium and phosphate resorption from bone)- Stimulation of osteoblastic activity- Decreases renal calcium reabsorption- Decreases renal phosphate reabsorption
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 31
Correct
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A 43-year old male is taken to the Emergency Room for a lacerated wound on the abdomen, situated above the umbilicus. A short segment of the small bowel has herniated through the wound.Which of these anatomic structures is the deepest structure injured in the case above?
Your Answer: Transversalis fascia
Explanation:The following structures are the layers of the anterior abdominal wall from the most superficial to the deepest layer:SkinFatty layer of the superficial fascia (Camper’s fascia)Membranous layer of the superficial fascia (Scarpa’s fascia)Aponeurosis of the external and internal oblique musclesRectus abdominis muscleAponeurosis of the internal oblique and transversus abdominisFascia transversalisExtraperitoneal fatParietal peritoneum
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This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 32
Correct
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You review the arterial blood gas (ABG) of a patient with lactic acidosis.Which SINGLE statement regarding lactic acidosis is true?
Your Answer: Type A lactic acidosis is typically due to tissue hypoxia
Explanation:Lactic acidosis is defined as a pH 5 mmol/L. It is a common finding in critically ill patients and is often associated with other serious underlying pathologies. The anion gap is raised in lactic acidosis.There are major adverse consequences of severe acidaemia, which affect all body systems, and there is an associated increase in mortality of critically ill patients with a raised lactate. The mortality associated with lactic acidosis despite full supportive treatment remains at 60-90%.Acquired lactic acidosis is classified into two subtypes:Type A is due to tissue hypoxiaType B is due to non-hypoxic processes affecting the production and elimination of lactateLactic acidosis can be extreme after a seizure but usually resolves spontaneously within a few hours.Left ventricular failure typically results in tissue hypoperfusion and a type A lactic acidosis.Some causes of type A and type B lactic acidosis are shown below: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 33
Incorrect
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Pancreatic ductal alkaline fluid secretion is mainly stimulated by which of the following hormones:
Your Answer: Pancreatic polypeptide
Correct Answer: Secretin
Explanation:Pancreatic exocrine secretion is controlled by:Parasympathetic stimulation which enhances secretion of both the enzyme and aqueous componentsSympathetic stimulation which inhibits pancreatic secretionSecretin which stimulates secretion of the alkaline-rich fluid from ductal cellsCholecystokinin which stimulates secretion of the enzyme-rich fluid from acinar cellsSomatostatin which inhibits secretion from both acinar and ductal cellsGastrin which stimulates pancreatic acinar cells to secrete digestive enzymes
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 34
Incorrect
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Among the following infectious diseases, which is typically considered to have an incubation period of 3 weeks and longer?
Your Answer: Mumps
Correct Answer: Infectious mononucleosis
Explanation:Infectious mononucleosis is caused by Epstein-Barr virus (EBV). The incubation period for EBV varies from 2 weeks to 2 months.The usual incubation period for rubella is 14 days; with a range of 12 to 23 days.Gonorrhoea has a short incubation period of approximately 2 to 7 days.The mumps virus can be isolated from infected saliva and swabs rubbed over the Stensen’s duct from 9 days before onset of symptoms until 8 days after parotitis appears.Scarlet fever, which appears within 1 to 2 days after bacterial infection, is characterized by a diffuse red rash that appears on the upper chest and spreads to the trunk and extremities. The rash disappears over the next 5 to7 days and is followed by desquamation.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 35
Incorrect
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Which of the following clinical features would you NOT expect to see in a tibial nerve palsy:
Your Answer: Loss of sensation over sole of the foot
Correct Answer: Weakened eversion of the foot
Explanation:Damage to the tibial nerve results in loss of plantarflexion of the ankle and weakness of inversion of the foot resulting in a shuffling gait, clawing of the toes and loss of sensation in its cutaneous distribution.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 36
Incorrect
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A 58-year-old man presented to the emergency room complaining of a chest pain that has been going on for the past 12 hours. Upon further investigation, a troponin test was ordered and the results came back negative. He was given a discharge order from the emergency department.Which of the following aspects of this test is considered the most significant in the decision made that it was safe to send the patient home?
Your Answer: Sensitivity
Correct Answer: Likelihood ratio
Explanation:The Likelihood Ratio (LR) is the likelihood that a given test result would be expected in a patient with the target disorder compared to the likelihood that that same result would be expected in a patient without the target disorder.The LR is used to assess how good a diagnostic test is and to help in selecting an appropriate diagnostic tests or sequence of tests. They have advantages over sensitivity and specificity because they are less likely to change with the prevalence of the disorder, they can be calculated for several levels of the symptom/sign or test, they can be used to combine the results of multiple diagnostic test and they can be used to calculate post-test probability for a target disorder.A LR greater than 1 produces a post-test probability which is higher than the pre-test probability. An LR less than 1 produces a post-test probability which is lower than the pre-test probability. When the pre-test probability lies between 30 and 70 per cent, test results with a very high LR (say, above 10) rule in disease. An LR below 1 produces a post-test probability les than the pre-test probability. A very low LR (say, below 0.1) virtually rules out the chance that the patient has the disease.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 37
Incorrect
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A 62-year-old woman is brought to the Emergency Department as she is acutely unwell. Her attendants inform you that she was recently started on lithium as a mood stabilizer. You instantly send a blood sample to check for lithium levels. What is the usual therapeutic range for lithium?
Your Answer: 0.8-1.4 mmol/l
Correct Answer: 0.4-0.8 mmol/l
Explanation:Lithium is the drug of choice for recurrent bipolar illness but should be carefully monitored as it has a very low therapeutic index. The normal therapeutic range is 0.4-0.8 mmol/l. The lower end of the range is usually the target for the elderly and as maintenance therapy. Toxicity is usually seen at levels >1.5 mmol/l. Samples should be taken 12 hours after the dose, and levels should be checked one week after starting therapy and one week after every change in dosage.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 38
Correct
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A patient presents with a history of renal problems, generalised weakness and palpitations. Her serum potassium levels are measured and come back at 6.2 mmol/L. An ECG is performed, and it shows some changes that are consistent with hyperkalaemia.Which of the following ECG changes is usually the earliest sign of hyperkalaemia? Select ONE answer only.
Your Answer: Peaked T waves
Explanation:Hyperkalaemia causes a rapid reduction in resting membrane potential leading to increased cardiac depolarisation and muscle excitability. This in turn results in ECG changes which can rapidly progress to ventricular fibrillation or asystole. Very distinctive ECG changes that progressively change as the K+level increases:K+>5.5 mmol/l – peaked T waves (usually earliest sign of hyperkalaemia), repolarisation abnormalitiesK+>6.5 mmol/l – P waves widen and flatten, PR segment lengthens, P waves eventually disappearK+>7.0 mmol/l – Prolonged QRS interval and bizarre QRS morphology, conduction blocks (bundle branch blocks, fascicular blocks), sinus bradycardia or slow AF, development of a sine wave appearance (a pre-terminal rhythm)K+>9.0 mmol/l – Cardiac arrest due to asystole, VF or PEA with a bizarre, wide complex rhythm.
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 39
Incorrect
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A 20-year-old with type I diabetes mellitus has an episode of hypoglycaemia following inadvertent administration of too much insulin.The mechanism by which insulin causes glucose to be transported into cells is?
Your Answer: Active transport
Correct Answer: Facilitated diffusion
Explanation:The only mechanism by which insulin facilitates uptake of glucose into cells is by facilitated diffusion through a family of hexose transporters.The major transporter used for glucose uptake is GLUT4. GLUT4 is made available in the plasma membrane by the action of insulin.When insulin concentrations are low, GLUT4 transporters are present in cytoplasmic vesicles, where they are cannot be used for transporting glucose.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 40
Incorrect
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Which of the following is not true regarding the structure and function of glomerular filtration membrane?
Your Answer: The arrangement of afferent and efferent arterioles maintains high hydrostatic pressure across glomerular capillaries
Correct Answer: The absence of a basement membrane reduces impedance to filtration
Explanation:The glomerular filtration membrane is composed of fenestrated capillary endothelium, basement membrane, and filtration slits. It is an organized, semipermeable membrane preventing the passage of most of the proteins into the urine. The anatomical arrangement of the glomerular filtration membrane maximizes the surface area available for filtration. The arrangement of its arterioles results in high hydrostatic pressures and facilitates filtration. Fenestrated capillary endothelium of the glomerular filtration membrane is with relatively large pores. It allows the free movement of plasma proteins and solutes but still restricts the movement of blood cells. Filtration slits are the smallest filters and restrict the movement of plasma proteins but still allow free movement of ions and nutrients. The glomerular basement membrane (GBM) is a critical component of the glomerular filtration membrane. Thus, it is not true that its absence will reduce the resistance of flow. The basement membrane is true to be more selective and contains negatively charged glycoproteins. However, it still allows free passage of water, nutrients, and ions. Severe structural abnormalities of the GBM can result in protein (albumin) leakage.
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 41
Correct
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A young male has presented to the Emergency Department with a sudden onset of severe palpitations, shortness of breath, and chest pain. A 12-lead ECG is recorded, and it shows a narrow complex tachycardia that points to a diagnosis of supraventricular tachycardia. Vagal manoeuvres are attempted but are unsuccessful in eliminating the arrhythmia. The next action plan is to use a drug to revert to sinus rhythm. Out of the following, which is the first-line treatment for supraventricular tachycardia?
Your Answer: Adenosine
Explanation:Paroxysmal supraventricular tachycardia is an intermittent tachycardia (HR > 100 bpm) and has the following characteristics:1. Sudden onset/offset (Contrast with sinus tachycardia)2. Electrical activity originates above the ventricle (Contrast with ventricular tachycardia)3. Produces narrow QRS complex (<120ms) The most common cause of PSVT is Atrioventricular nodal re-entrant tachycardia (AVNRT), most common in young women with a mean age onset of 32 years old. There are recurrent episodes of palpitations, and most of the episodes spontaneously. Sometimes, some vagal manoeuvres are required:1. Valsalva manoeuvre2. immersing the face in ice-cold water3. carotid sinus massage.If PSVT keeps persisting or is causing severe symptoms, the treatment of choice is intravenous adenosine. The patient’s ECG should be continuously monitored throughout the treatment. The recommended doses in adults are as follows:- Initial dose of adenosine is 6 mg by rapid IV bolus- If unsuccessful, give another dose of adenosine 12 mg by rapid IV bolus- If unsuccessful, give a further dose of adenosine 12 mg by rapid IV bolusThe latest ALS guidelines advocate 18 mg for the third dose, whereas the BNF/NICE guidelines advocate 12 mg.If adenosine fails or is contraindicated, intravenous verapamil can be used as an alternative, but it should be avoided in patients recently treated with beta-blockers.Synchronized electrical cardioversion will be necessary with signs of hemodynamic instability or if drug treatment has failed to restore sinus rhythm.Recurrent episodes of paroxysmal supraventricular tachycardia can be treated by catheter ablation or prevented with drugs such as flecainide, sotalol, diltiazem, or verapamil.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 42
Correct
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An elderly female has a bacterial infection and you are asked to prescribe an antibiotic to her. This antibiotic is a nucleic acid synthesis inhibitor.Which of the following antimicrobial drugs will be prescribed to this patient?
Your Answer: Metronidazole
Explanation:Metronidazole and the other 5-nitroimidazole agents inhibit nucleic acid synthesis by forming toxic free radical metabolites in the bacterial cell that damage DNA. Vancomycin inhibits cell wall peptidoglycan formation by binding the D-Ala-D-Ala portion of cell wall precursors. Erythromycin inhibits protein synthesis and blocks translocation by binding to the 23S rRNA of the 50S ribosomal subunit.Chloramphenicol blocks peptidyl transferase at 50S ribosomal subunit.Gentamicin, an aminoglycoside antibiotic, acts by binding to the 30S subunit of the bacterial ribosome inhibiting the binding of aminoacyl-tRNA and thus preventing initiation of protein synthesis.An overview of the different mechanisms of action of the various types of antimicrobial agents is shown below:1. Inhibition of cell wall synthesis- Penicillins- Cephalosporins- Vancomycin2. Disruption of cell membrane function- Polymyxins- Nystatin- Amphotericin B3. Inhibition of protein synthesis- Macrolides- Aminoglycosides- Tetracyclines- Chloramphenicol4. Inhibition of nucleic acid synthesis- Quinolones- Trimethoprim- 5-nitroimidazoles- Rifampicin5. Anti-metabolic activity- Sulphonamides- Isoniazid
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 43
Incorrect
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Fracture of the medial epicondyle would result to the following, except
Your Answer: Weakness of wrist flexion
Correct Answer: Weakness of abduction of the thumb
Explanation:Thumb abduction is mediated by the abductor pollicis longus and brevis, which are innervated by the radial and median nerves, respectively.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 44
Correct
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Bordetella pertussis causes which of the following infectious diseases:
Your Answer: Whooping cough
Explanation:Bordetella pertussis causes whooping cough. Acute bronchiolitis is typically caused by respiratory syncytial virus. Parainfluenza virus is the most common cause of croup. Acute epiglottitis is usually caused by an infection with Haemophilus influenzae type b (Hib) bacteria. The common cold may be caused by a number of viruses including rhinovirus and coronavirus.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 45
Incorrect
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Which of the following bacteria is a rod-shaped, oxidase-positive, opportunistic gram-negative bacteria that can cause a catheter-related urinary tract infection (UTI)?
Your Answer: Klebsiella pneumoniae
Correct Answer: Pseudomonas aeruginosa
Explanation:Listeria monocytogenes is a gram-positive bacteria that does not produce spores. Staphylococcus aureus is a gram-positive bacteria, while Candida albicans is a gram-positive yeast with a single bud. Among the choices, gram-negative bacteria include only Klebsiella pneumoniae and Pseudomonas aeruginosa. Pseudomonas aeruginosa is an oxidase-positive bacterium, while Klebsiella pneumoniae is an oxidase-negative bacterium. P. aeruginosa can cause urinary tract infections (UTIs) and is spread through poor hygiene or contaminated medical equipment or devices, such as catheters that haven’t been fully sterilized.
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This question is part of the following fields:
- Infections
- Microbiology
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Question 46
Incorrect
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Which of the following statements about propofol is TRUE:
Your Answer: If accidentally injected outside a vein it can cause tissue necrosis.
Correct Answer: Propofol has some antiemetic action.
Explanation:Propofol has some antiemetic properties. It’s for this reason that it’s used to treat postoperative nausea and vomiting. Propofol is mostly processed in the liver, with the kidneys excreting just around 1% of it unaltered. Propofol, unlike thiopental, does not produce tissue necrosis when it is extravasated. Propofol lowers intracranial pressure via lowering brain metabolic rate and cerebral blood flow. Propofol is thought to be safe for people with bronchial asthma and chronic obstructive pulmonary disease.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 47
Incorrect
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Which of the following statements is correct regarding gentamicin?
Your Answer: Hepatotoxicity is the most common adverse effect at toxic doses.
Correct Answer: Gentamicin is ineffective against anaerobic bacteria.
Explanation:Gentamicin is the aminoglycoside of choice in the UK and is a parenterally administered, broad spectrum antibiotic typically used for moderate to severe gram negative infections. However, it is inactive against anaerobes. There is poor activity against haemolytic streptococci and pneumococci. It is usually given in conjunction with a penicillin or metronidazole (or both) when used for the blind treatment of undiagnosed serious infections. Nephrotoxicity and ototoxicity are the main toxic effects due to damage to the vestibulocochlear nerve (CN VIII).It is contraindicated in myasthenia gravis and should be used with great care in renal disease as it may result in accumulation and a higher risk of toxic side effects.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 48
Correct
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Regarding acute lymphoblastic leukaemia (ALL), which of the following statements is CORRECT:
Your Answer: ALL is the most common malignancy of childhood.
Explanation:Acute lymphoblastic leukaemia (ALL) is caused by an accumulation of lymphoblasts in the bone marrow and is the most common malignancy of childhood. The incidence of ALL is highest at 3 – 7 years, with 75% of cases occurring before the age of 6. 85% of cases are of B-cell lineage. Haematological investigations reveal a normochromic normocytic anaemia with thrombocytopenia in most cases. The total white cell count may be decreased, normal or increased. The blood film typically shows a variable number of blast cells. The bone marrow is hypercellular with >20% blast cells.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 49
Correct
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The Frank-Starling curve is shifted downhill in heart failure due to which of the following?
Your Answer: Decrease in contractility
Explanation:The Frank–Starling mechanism states that the left ventricle can increase its force of contraction and hence stroke volume in response to increases in venous return and thus preload. Changes in afterload or inotropy cause the Frank–Starling curve to rise or fall. In heart failure, the Frank–Starling curve is shifted downward (flattened), requiring higher venous return and filling pressure to enhance contractility and stroke volume.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 50
Incorrect
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Which of the following best describes digoxin:
Your Answer: A negative inotrope and negative chronotrope
Correct Answer: A positive inotrope and negative chronotrope
Explanation:Digoxin is a cardiac glycoside used in the treatment of atrial fibrillation and flutter, and congestive cardiac failure. It acts by inhibiting the membrane Na/K ATPase in cardiac myocytes. This raises intracellular sodium concentration and increases intracellular calcium availability indirectly via Na/Ca exchange. The increase in intracellular calcium levels causes an increases the force of myocardial contraction (positive inotrope), and slows the heart rate (negative chronotrope).
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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