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Question 1
Incorrect
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Which of the following is NOT a common side effect of adenosine:
Your Answer: Dyspnoea
Correct Answer: Yellow vision
Explanation:Common side effects of adenosine include:ApprehensionDizziness, flushing, headache, nausea, dyspnoeaAngina (discontinue)AV block, sinus pause and arrhythmia (discontinue if asystole or severe bradycardia occur)
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 2
Correct
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A 43-year-old woman presented to the emergency room after an incident of slipping and falling onto her back and left hip. Upon physical examination, it was noted that she has pain on hip abduction, but normal hip extension. Which of the following muscles was most likely injured in this case?
Your Answer: Gluteus medius
Explanation:The primary hip extensors are the gluteus maximus and the hamstrings such as the long head of the biceps femoris, the semitendinosus, and the semimembranosus. The extensor head of the adductor magnus is also considered a primary hip extensor.The hip abductor muscle group is located on the lateral thigh. The primary hip abductor muscles include the gluteus medius, gluteus minimus, and tensor fasciae latae.The secondary hip abductors include the piriformis, sartorius, and superior fibres of the gluteus maximus.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 3
Correct
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Regarding postural hypotension, which of the following statements is INCORRECT:
Your Answer: Postural hypotension usually causes a reflex bradycardia.
Explanation:On standing from a prone position, gravity causes blood to pool in veins in the legs. Central venous pressure (CVP) falls, causing a fall in stroke volume and cardiac output (due to Starling’s law) and thus a fall in blood pressure. Normally this fall in BP is rapidly corrected by the baroreceptor reflex which causes venoconstriction (partially restoring CVP), and an increase in heart rate and contractility, so restoring cardiac output and blood pressure. Impaired autonomic nervous activity in the elderly accounts for the greater likelihood of postural hypotension. Any symptoms of dizziness, blurred vision or syncope is due to a transient fall in cerebral perfusion that occurs before cardiac output and mean arterial pressure (MAP) can be corrected.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 4
Correct
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Which of the following conditions manifests hyperkalaemia as one of its symptoms?
Your Answer: Congenital adrenal hyperplasia
Explanation:Plasma potassium greater than 5.5 mmol/L is hyperkalaemia or elevated plasma potassium level. Among the causes of hyperkalaemia include congenital adrenal hyperplasia. Congenital adrenal hyperplasia is a general term referring to autosomal recessive disorders involving a deficiency of an enzyme needed in cortisol and/or aldosterone synthesis. The level of cortisol and/or aldosterone deficiency affects the clinical manifestations of congenital adrenal hyperplasia. When it involves hypoaldosteronism, it can result in hyponatremia and hyperkalaemia. While hypercortisolism can cause hypoglycaemia.The other causes of hyperkalaemia may include renal failure, excess potassium supplementation, Addison’s disease (adrenal insufficiency), renal tubular acidosis (type 4), rhabdomyolysis, burns, trauma, Tumour lysis syndrome, acidosis, and medications such as ACE inhibitors, angiotensin receptor blockers, NSAIDs, beta-blockers, digoxin, and suxamethonium. Bartter’s syndrome is characterized by hypokalaemic alkalosis with normal to low blood pressure. Type 1 and 2 renal tubular acidosis both cause hypokalaemia. Gitelman’s syndrome is a defect of the distal convoluted tubule of the kidney. It causes metabolic alkalosis with hypokalaemia and hypomagnesemia. And excessive liquorice ingestion causes hypermineralocorticoidism and hypokalaemia as well. Thus, among the choices, only congenital adrenal hyperplasia can cause hyperkalaemia.
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 5
Correct
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Dehydration causes a significant increase in the amount of this hormone?
Your Answer: Antidiuretic hormone
Explanation:Antidiuretic hormone induces the kidneys to release less water, resulting in reduced urine production. In the case of dehydration, ADH levels rise, resulting in a considerable decrease in urine output as well as an increase in plasma protein, blood Hct, and serum osmolality.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 6
Correct
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Which of the following is NOT a common side effect of antihistamines:
Your Answer: Tremor
Explanation:Common side effects of antihistamines may include:Anticholinergic effects (blurred vision, dry mouth, urinary retention)HeadacheGastrointestinal disturbancesPsychomotor impairment (sedation, dizziness and loss of appetite)These side effects are significantly reduced with second-generation agents.
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 7
Correct
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All of the following cause bronchodilation, EXCEPT for:
Your Answer: Stimulation of irritant receptors
Explanation:Factors causing bronchodilation: Via beta2-adrenoceptorsSympathetic stimulation: Adrenaline (epinephrine)Beta2-adrenergic agonists e.g. salbutamolAnticholinergic and muscarinic antagonists e.g. ipratropium
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 8
Correct
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A 55-year-old woman with mild dyspepsia seeks advice from her pharmacist on how to deal with her symptoms. In the first instance, the pharmacist advises her to take an over-the-counter antacid. She buys an antacid that contains aluminium hydroxide, which relieves her symptoms but has a negative side effect.She's most likely to have developed which of the following side effects?
Your Answer: Constipation
Explanation:Aluminium hydroxide is a common antacid that is used to treat ulcer dyspepsia and non-erosive gastro-oesophageal reflux disease.When antacids containing aluminium salts are given to patients with renal impairment, there is a risk of accumulation and aluminium toxicity. If renal function is normal, aluminium accumulation does not appear to be a risk.Because it reduces gastrointestinal phosphate absorption, aluminium hydroxide can also be used to treat hyperphosphatemia in patients with renal failure.Magnesium-based antacids are generally laxative, whereas aluminium-based antacids can be constipating. Renal impairment, angioedema, and anaphylaxis are not significantly increased.
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This question is part of the following fields:
- Gastrointestinal Pharmacology
- Pharmacology
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Question 9
Incorrect
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One of these statements about significance tests is true.
Your Answer: The power of a study is the probability of correctly accepting the null hypothesis when it is true
Correct Answer: A p value of less than 1 in 20 is considered ‘statistically significant’
Explanation:The p value is statistically significant when it is less than 0.05 (5% or 1 in 20).Statistical significance is not the same as clinical significance. The null hypothesis states that there is no difference between the groups.The power of a study is the probability of correctly rejecting the null hypothesis when it is false.A type I error occurs when the null hypothesis has been rejected when it is true. A type II error occurs when the null hypothesis has been accepted when it is actually false.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 10
Correct
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A 58-year-old woman presents with symptoms of increase in weight, proximal muscular weakening and withering, easy bruising, and acne. You notice that she has a full, plethoric aspect to her face, as well as significant supraclavicular fat pads, when you examine her. She has previously been diagnosed with Cushing's syndrome.Which of the following biochemical profiles best supports this diagnosis?
Your Answer: Hypokalaemic metabolic alkalosis
Explanation:Cushing’s syndrome is a group of symptoms and signs brought on by long-term exposure to high amounts of endogenous or exogenous glucocorticoids. Cushing’s syndrome affects about 10-15 persons per million, and it is more common in those who have had a history of obesity, hypertension, or diabetes.A typical biochemical profile can help establish a diagnosis of Cushing’s syndrome. The following are the primary characteristics:HypokalaemiaAlkalosis metabolique
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 11
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 12
Correct
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Which of the following is a primary action of calcitonin:
Your Answer: Decreased bone resorption through inhibition of osteoclast activity
Explanation:Calcitonin is a 32 amino acid polypeptide that is primarily synthesised and released by the parafollicular cells (C-cells) of the thyroid gland in response to rising or high levels of plasma Ca2+ions. Its primary role is to reduce the plasma calcium concentration, therefore opposing the effects of parathyroid hormone.Secretion of calcitonin is stimulated by:- Increased plasma calcium concentration- Gastrin- Pentagastrin- The main actions of calcitonin are:- Inhibition of osteoclastic activity (decreasing calcium and phosphate resorption from bone)- Stimulation of osteoblastic activity- Decreases renal calcium reabsorption- Decreases renal phosphate reabsorption
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 13
Correct
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Which of the following best describes the correct administration of adrenaline for a shockable rhythm in adult advanced life support?
Your Answer: Give 1 mg of adrenaline after the third shock and every 3 - 5 minutes thereafter
Explanation:The correct administration of IV adrenaline 1 mg (10 mL of 1:10,000 solution) is that it should be given after 3 shocks and every 3 – 5 minutes/after alternate shocks thereafter.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 14
Incorrect
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A 2-day-old male is referred to a tertiary care hospital by the community midwife after a home visit due to jaundice and dyspnoea. After history and examination, the relevant blood work is performed, and the baby is found to have conjugated hyperbilirubinemia. The paediatric team suspects a hepatic origin for jaundice based on the findings. Which one of the following aetiologies is the most likely cause of jaundice in this case?
Your Answer: Biliary atresia
Correct Answer: Alpha 1-antitrypsin deficiency
Explanation:The presence of dyspnoea makes alpha-1 antitrypsin deficiency the more likely diagnosis as biliary atresia does not cause respiratory symptoms. Deficiency of the enzyme alpha-1 antitrypsin causes uninhibited elastase activity and a decrease in elastic tissue. This causes liver cirrhosis leading to an elevation of conjugated bilirubin and emphysema in the lungs.Rhesus disease, hereditary spherocytosis and breast milk jaundice cause an elevation of unconjugated bilirubin thus ruling it out in this case. Breast milk jaundice occurs due to an inability of the newborn to metabolize the proteins in breast milk. Rhesus disease occurs when an Rh negative mother gives birth to an Rh positive baby. The jaundice would have been accompanied by anaemia and oedema. Hereditary spherocytosis occurs due to extravascular haemolysis as defective RBCs are removed by the spleen. The patient would present with jaundice, splenomegaly and possibly an aplastic crisis (if Parvovirus B19 infection).
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 15
Incorrect
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Which of the following is NOT a typical feature of an abducens nerve palsy:
Your Answer: Adducted eye at rest
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 16
Incorrect
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On which of the following types of receptors does loperamide act?
Your Answer: Muscarinic receptors
Correct Answer: Opioid receptors
Explanation:Loperamide inhibits acetylcholine release from the myenteric plexus acts by action on opioid mu-receptors, and this then reduces bowel motility. The intestinal transit time is increased, thereby facilitating water reabsorption.
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This question is part of the following fields:
- Gastrointestinal
- Pharmacology
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Question 17
Correct
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A 29-year-old man is diagnosed with a severe case of asthma.In the treatment of acute asthma in adults, which of the following is NOT recommended?
Your Answer: Nebulised magnesium
Explanation:There is no evidence to support the use of nebulized magnesium sulphate in the treatment of adults at this time.In adults with acute asthma, the following medication dosages are recommended:By using an oxygen-driven nebuliser, you can get 5 milligrams of salbutamol.500 mcg ipratropium bromide in an oxygen-driven nebuliserOral prednisolone 40-50 mg100 mg hydrocortisone intravenous1.2-2 g magnesium sulphate IV over 20 minutesWhen inhaled treatment is ineffective, intravenous salbutamol (250 mcg IV slowly) may be explored (e.g. a patient receiving bag-mask ventilation).Following senior counsel, current ALS recommendations propose that IV aminophylline be explored in severe or life-threatening asthma. If utilized, a loading dose of 5 mg/kg should be administered over 20 minutes, then a 500-700 mcg/kg/hour infusion should be given. To avoid toxicity, serum theophylline levels should be kept below 20 mcg/ml.
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This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 18
Correct
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All of the following typically occurs as part of normal passive expiration except:
Your Answer: Contraction of the internal intercostal muscles
Explanation:Passive expiration is produced primarily by relaxation of the inspiratory muscles (diaphragm and external intercostal muscles) in addition to the elastic recoil of the lungs. In expiration, several movements occur. There are:1. depression of the sternal ends of the ribs (‘pump handle’ movement), 2. depression of the lateral shafts of the ribs (‘bucket handle’ movement) and 3. elevation of the diaphragm. These result in a reduction of the thorax in an anteroposterior, transverse and vertical direction respectively. There is then a decreased intrathoracic volume and increased intrathoracic pressure and air is forced out of the lungs.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 19
Incorrect
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A 55-year-old woman with a known history of bronchiectasis has lung function testing carried out and is found to have significant airways obstruction.Which of the following lung volumes or capacities is LEAST likely to be decreased in this case? Select ONE answer only.
Your Answer: Expiratory reserve volume
Correct Answer: Functional residual capacity
Explanation:Obstructive lung disorders are characterised by airway obstruction. Many obstructive diseases of the lung result from narrowing of the smaller bronchi and larger bronchioles, often because of excessive contraction of the smooth muscle itself.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 = FEV1of 50-79%Severe airflow obstruction = FEV1of 30-49%Very severe airflow obstruction = FEV1<30%.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 20
Incorrect
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A 29-year-old woman presents with night sweats, fever, and haemoptysis. A diagnosis of tuberculosis was suspected.Which of the following statements regarding the diagnosis of tuberculosis is considered correct?
Your Answer: Mycobacteria tuberculosis appears blue on acid-fast staining
Correct Answer: Mycobacteria tuberculosis can be typed using a RFLP method
Explanation:Although a variety of clinical specimens may be submitted to thelaboratory to recover MTB and NTM, respiratory secretions suchas sputum and bronchial aspirates are the most common. Anearly-morning specimen should be collected on three consecutivedays, although recent studies have suggested that the addition ofa third specimen does not significantly increase the sensitivityof detecting Mycobacteria.Mycobacterium tuberculosis appear red on acid-fast staining because they take up the primary stain, which is carbolfuchsin, and is not decolorized by the acid alcohol anymore.Culture on Lowenstein-Jensen medium should be read within 5 to 7 days after inoculation and once a week thereafter for up to 8 weeks.Nucleic acid amplification assays designed to detect M. tuberculosis complexbacilli directly from patient specimens can be performed in as little as 6 to 8 hours on processed specimens.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 21
Correct
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Ipratropium bromide should be used with caution in patients with which of the following conditions:
Your Answer: Prostatic hyperplasia
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
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Question 22
Correct
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A young 20-year-old boy is a known case of type I diabetes mellitus. Today, he presents with polyuria, polydipsia, and abdominal pain in the emergency department. His blood sugar is drawn, which is markedly elevated to 7 mmol/L. Quick ABGs are drawn, which show metabolic acidosis. You diagnose the patient to be suffering from diabetic ketoacidosis (DKA) and immediately commence its treatment protocol in which insulin is also administered. Out of the following, which parameter is MOST likely to change due to initiating insulin?
Your Answer: Potassium
Explanation:Diabetes ketoacidosis is an acute complication of diabetes mellitus. Insulin is administered to achieve euglycemia, and crystalloids or colloidal solution is administered to achieve euvolemia and euelectrolytaemia. Potassium levels severely fluctuate during the treatment of DKA, hypokalaemia being more common. Insulin promotes the cell to take up potassium from the extracellular space via increased sodium-potassium pump activity. It is important to monitor potassium levels during the treatment of DKA regularly. It is widely suggested that the normal saline shall be used for initial resuscitation, and once the potassium level is retrieved, the patient can be started on potassium replacement should the serum potassium level be between 3.3 and 4.5 mmol/L If potassium levels fall below 3.3 mmol/l, insulin administration may need to be interrupted to correct the hypokalaemia.
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This question is part of the following fields:
- Endocrine Pharmacology
- Pharmacology
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Question 23
Incorrect
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A 66-year-old male is brought to your clinic by his wife with the complaint of increasing confusion and disorientation over the past three days, along with decreased urination. She reports that he has been complaining of increasing pain in his back and ribs over the past three months. On examination, the patient looks anaemic, is not oriented in time, place and person and has tenderness on palpation of the lumbar spine and the 10th, 11th and 12th ribs. Blood tests show anaemia which is normocytic, normochromic, raised urea and creatinine and hypercalcemia. Which one of the following diagnoses is most likely in this case?
Your Answer: Metastatic prostate cancer
Correct Answer: Multiple myeloma
Explanation:Multiple myeloma is a clonal abnormality affecting plasma cells in which there is an overproduction of functionless immunoglobulins. The most common patient complaint is bone pain, especially in the back and ribs. Anaemia and renal failure are common, along with hypercalcemia. Hypercalcemia may lead to an altered mental status, as in this case. Chronic lymphocytic leukaemia occurs due to the overproduction of lymphocytes, usually B cells. CLL may present with an asymptomatic elevation of B cells. Patients are generally more than 50 years old and present with non-specific fatigue and weight loss symptoms.There is no history of alcohol abuse in this case. Furthermore, patients with a history of alcohol abuse may have signs of liver failure, which are not present here. Metastatic prostate cancer would most often cause lower backache as it metastasises first to the lumbar spine via the vertebral venous plexus. A patient with Vitamin B12 deficiency would have anaemia, megaloblastic, hypersegmented neutrophils, and signs of peripheral neuropathy.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 24
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 25
Correct
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The most important Complement protein for antigen opsonization is:
Your 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 26
Incorrect
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A 58-year-old woman presents with symptoms of increase in weight, proximal muscular weakening and withering, easy bruising, and acne. You notice that she has a full, plethoric aspect to her face, as well as significant supraclavicular fat pads, when you examine her. She has previously been diagnosed with Cushing's syndrome.Cushing's syndrome is most commonly caused by which of the following?
Your Answer: Adrenal adenoma
Correct Answer: Iatrogenic administration of corticosteroids
Explanation:Cushing’s syndrome is a group of symptoms and signs brought on by long-term exposure to high amounts of endogenous or exogenous glucocorticoids. Cushing’s syndrome affects about 10-15 persons per million, and it is more common in those who have had a history of obesity, hypertension, or diabetes.Iatrogenic corticosteroid injection is the most prevalent cause of Cushing’s syndrome. Cushing’s illness is the second most prevalent cause of Cushing’s syndrome. Cushing’s disease is distinct from Cushing’s syndrome in that it refers to a single cause of the illness, a pituitary adenoma that secretes high quantities of ACTH, which raises cortisol levels.Cushing’s syndrome has several endogenous sources, including:Cushing’s disease is caused by a pituitary adenoma.Adrenal adenoma Ectopic corticotropin syndrome, e.g. small cell cancer of the lungAdrenal carcinoma is a cancer of the adrenal gland.Hyperplasia of the adrenal glands
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 27
Correct
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A 6-year-old child presents with profuse watery diarrhoea and dehydration. Which of the following statements is considered correct regarding infective diarrhoea?
Your Answer: E.Coli can cause diarrhoea and renal failure
Explanation:E. coli may cause several different gastrointestinal syndromes. Based on virulence factors, clinical manifestation, epidemiology, and different O and H serotypes, there are five major categories of diarrheagenic E. coli, enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC), enteropathogenic E. coli (EPEC), enterohemorrhagic E. coli (EHEC), and enteroadherent, which includes diffusely adherent E. coli (DAEC) and enteroaggregative E. coli (EAEC). These five categories are sometimescollectively referred to as enterovirulent E. coli or diarrheagenic E. coli.Norwalk virus is part of the Caliciviridae family of viruses which are single-stranded RNA viruses and are the most common cause of infectious gastroenteritis in the US.Rotaviruses are the most common cause of viral gastroenteritisin infants and children. With the introduction in 2006 of a human-bovine rotavirus vaccine (RV5; RotaTeq, Merck), a delay in the onset of rotavirusseason was seen. RotaTeq is a series of three oral vaccines beginning at 6 to 12 weeks of age. A second vaccine, Rotarix (RV1; GlaxoSmithKline, Middlesex, England), was approved in June 2008.Cryptosporidium causes an illness characterized by abdominal cramping, watery diarrhoea, vomiting, fever, and anorexia. This organism is resistant to chlorine, so public swimming pools can be the source of an outbreak.G. lamblia has a worldwide distribution and has frequently been identified as the causative agent of outbreaks of gastroenteritis and traveller’s diarrhoea.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 28
Correct
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Which of the following is characterised by passive carrier-mediated transport down a chemical concentration gradient:
Your Answer: Facilitated diffusion
Explanation:Facilitated diffusion is the process of spontaneous passive transport of molecules or ions down their concentration gradient across a cell membrane via specific transmembrane transporter (carrier) proteins. The energy required for conformational changes in the transporter protein is provided by the concentration gradient rather than by metabolic activity.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 29
Incorrect
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You review an 18-months-old child who seems to be having a reaction following an immunisation she took earlier in the day.Which statement concerning immunity and vaccination is true?
Your Answer: Passively acquired immunity usually leads to long-lasting resistance to infection
Correct Answer: The strongest immunological response is seen with natural immunity
Explanation:Vaccination induces ACTIVE adaptive immunity. Actively acquired immunity involves the development of an immune response either due to vaccination or natural exposure to a pathogen and leads to long-lasting resistance to infection.Immediate protection is achieved with injection of immunoglobulin. The protection is transient lasting only a few weeks and is useful as post-exposure prophylaxis. Passively acquired immunity usually leads to short-lasting resistance to infection because it does not involve a host immune response. With inactivated bacteria, a series of primary vaccinations is usually required to induce an adequate immune response. In most cases, boosters are required to sustain adequate immunity.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 30
Correct
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Which of the following medications may lessen warfarin's anticoagulant effect:
Your Answer: Phenytoin
Explanation:Phenytoin will decrease the level or effect of warfarin by affecting hepatic/intestinal enzyme CYP3A4 metabolism.Metronidazole will increase the level or effect of warfarin by affecting hepatic enzyme CYP2C9/10 metabolism.NSAIDs, when given with Warfarin, increase anticoagulation.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 31
Correct
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A mother has serious concerns about vaccinating her child. She has read about many contraindications and risks in the papers and would like to discuss them with you.One of these is a valid contraindication to vaccination.
Your Answer: None of the other options
Explanation:The options listed in this question are not true contraindications to vaccination. Therefore, the correct answer is ‘none of the other options’.The contraindications to vaccination are:Confirmed anaphylactic reaction to a previous dose of the vaccine or a vaccine containing the same antigens.A confirmed anaphylactic reaction to another component in the vaccine.
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 32
Correct
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What is the main mechanism of action of cyclizine:
Your Answer: Histamine-H1 antagonist
Explanation:Antihistamines e.g. cyclizine, are effective against nausea and vomiting caused by many different conditions, including motion sickness and vertigo. These agents act by inhibiting histamine pathways, and cholinergic pathways involved in transmission from the vestibular apparatus to the vomiting centre. There is no evidence that any one antihistamine is superior to another but their duration of action and incidence of adverse effects differ. Adverse effects include drowsiness and antimuscarinic effects such as blurred vision, dry mouth, urinary retention, constipation and confusion.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 33
Incorrect
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ACE inhibitors are indicated for all of the following EXCEPT for:
Your Answer: Secondary prevention of cardiovascular disease
Correct Answer: Angina
Explanation:ACE inhibitors have many uses and are generally well tolerated. They are indicated for:Heart failureHypertensionDiabetic nephropathySecondary prevention of cardiovascular events
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 34
Correct
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The Meissner’s plexus acts as the main control for gastrointestinal secretion and local blood flow within the gut.The Meissner’s plexus lies in which layer of the gut wall?
Your Answer: Submucosa
Explanation:The Meissner’s plexus (submucosal plexus), an enteric nervous plexus, acts as the main control for gastrointestinal secretion and local blood flow within the gut.It is located in the submucosal layer on the inner surface of the muscularis externa.
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This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 35
Correct
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A 28-year-old female patient with a history of hypothyroidism arrives at the Emergency Department after taking 30 of her 200 mcg levothyroxine tablets. She tells you she's 'tired of life' and 'can't take it any longer.' She is currently asymptomatic, and her findings are all within normal limits.What is the minimum amount of levothyroxine that must be taken before thyrotoxicosis symptoms appear?
Your Answer: >10 mg
Explanation:An overdose of levothyroxine can happen by accident or on purpose. Intentional overdosing is sometimes done to lose weight, but it can also happen in patients who are suicidal. The development of thyrotoxicosis, which can lead to excited sympathetic activity and high metabolism syndrome, is the main source of concern. The time between ingestion and the emergence of clinical features associated with an overdose is often quite long.After a levothyroxine overdose, the majority of patients are asymptomatic. Symptoms and signs are usually only seen in patients who have taken more than 10 mg of levothyroxine in total.The following are the most commonly seen clinical features in patients developing clinical features:TremorAgitationSweatingInsomniaHeadacheIncreased body temperatureIncreased blood pressureDiarrhoea and vomitingLess common clinical features associated with levothyroxine overdose include:SeizuresAcute psychosisThyroid stormTachycardiaArrhythmiasComaThe continued absorption of the ingested levothyroxine causes a progressive rise in both total serum T4 and total serum T3 levels in the first 24 hours after an overdose. However, in some cases, the biochemical picture is completely normal. Thyroid function tests are not always recommended after a thyroxine overdose. Although elevated thyroxine levels are common, they have little clinical significance and have no impact on treatment. Following a levothyroxine overdose, the following biochemical features are common:T4 and T3 levels in the blood are elevated.Free T4 and Free T3 levels are higher.TSH levels in the blood are low.If the patient is cooperative and more than 10 mg of levothyroxine has been consumed, activated charcoal can be given (i.e., likely to become symptomatic)Within an hour of ingestion, the patient presents.The treatment is mostly supportive and aimed at managing the sympathomimetic symptoms that come with levothyroxine overdose. If beta blockers aren’t an option, try propranolol 10-40 mg PO 6 hours or diltiazem 60-180 mg 8 hours.
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This question is part of the following fields:
- Endocrine Pharmacology
- Pharmacology
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Question 36
Correct
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The most common type of adult leukaemia is chronic lymphocytic leukaemia (CLL). It develops as a result of lymphocyte clonal proliferation.Which of the following statements about CLL is CORRECT?
Your Answer: It is most commonly discovered as an incidental finding
Explanation:CLL (chronic lymphocytic leukaemia) is the most common type of chronic lymphoid leukaemia, with a peak incidence between the ages of 60 and 80. It is the most common type of leukaemia in Europe and the United States, but it is less common elsewhere. The CLL tumour cell is a mature B-cell with low immunoglobulin surface expression (IgM or IgD). The average age at diagnosis is 72 years, with only 15% of cases occurring before the age of 50. The male-to-female ratio is about 2:1. Over 80% of cases are identified by the results of a routine blood test, which is usually performed for another reason. Lymphocytic anaemia, thrombocytopenia, and normochromic normocytic anaemia are common laboratory findings. Aspiration of bone marrow reveals up to 95% lymphocytic replacement of normal marrow elements.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 37
Correct
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Antidiuretic hormone (ADH) levels are found to be increased in a young lady with unexplained hyponatraemia.Which of the following is a result of the release of ADH?
Your Answer: Small volumes of concentrated urine
Explanation:ADH, or antidiuretic hormone, is a hormone that regulates water and electrolyte balance. It is released in response to a variety of events, the most important of which are higher plasma osmolality or lower blood pressure. ADH increases plasma volume and blood pressure via acting on the kidneys and peripheral vasculature.ADH causes extensive vasoconstriction by acting on peripheral V1 Receptors.ADH binds to B2 Receptors in the terminal distal convoluted tubule and collecting duct of the kidney, increasing transcription and aquaporin insertion in the cells that line the lumen. Aquaporins are water channels that allow water to pass through the tubule and into the interstitial fluid via osmosis, lowering urine losses.The permeability of the distal collecting duct (the section within the inner medulla) to urea is likewise increased by ADH. More urea travels out of the tubule and into the peritubular fluid, contributing to the counter current multiplier, which improves the Loop of Henle’s concentrating power.Overall, there is enhanced urea and water reabsorption in the presence of ADH, resulting in modest amounts of concentrated urine. There is minimal urea and water reabsorption in the absence of ADH, resulting in huge amounts of dilute urine.
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 38
Incorrect
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Which of the following clinical features is most suggestive of a lesion of the frontal lobe:
Your Answer: Hemispatial neglect
Correct 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 39
Incorrect
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A 33-year-old woman demonstrates right-sided superior homonymous quadrantanopia upon visual field testing. A diagnosis of a brain tumour has been established.Which of the following anatomical points in the visual pathway has the lesion occurred?
Your Answer: Upper optic radiation
Correct Answer: Lower optic radiation
Explanation:Homonymous quadrantanopia is not a disease; it is a clinical finding that points towards a lesion of the optic radiations coursing through the temporal lobe.Homonymous superior quadrantanopia is caused by damage to the contralateral inferior parts of the posterior visual pathway: the inferior optic radiation (temporal Meyer loop), or the inferior part of the occipital visual cortex below the calcarine fissure.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 40
Correct
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All of the following statements are incorrect about insulin except:
Your Answer: Proinsulin is cleaved into insulin and C peptide.
Explanation:Proinsulin is synthesised as a single-chain peptide. A connecting peptide (C peptide) within storage granules is removed by proteases to yield insulin. Insulin:1. is a polypeptide hormone consisting of two short chains (A and B) linked by disulphide bonds. 2. is produced by beta cells, located centrally within the islets of Langerhans, in the endocrine tissues of the pancreas. 3. release is stimulated initially during eating by the parasympathetic nervous system and gut hormones such as secretin. However, most output is driven by the rise in plasma glucose concentration that occurs after a meal. 4. effects 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 41
Correct
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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: 0.4
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 42
Correct
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Which of the following is NOT a common side effect of amiodarone:
Your Answer: Blue/green teeth discolouration
Explanation:Common side effects of amiodarone include: Bradycardia, Nausea and vomiting, Thyroid disorders – hypothyroidism and hyperthyroidism, Persistent slate grey skin discoloration, Photosensitivity, Pulmonary toxicity (including pneumonitis and fibrosis), Hepatotoxicity, Corneal microdeposits (sometimes with night glare), Peripheral neuropathy and Sleep disorders.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 43
Correct
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What is the mechanism of action of penicillin antibiotics:
Your Answer: Inhibition of bacterial cell wall synthesis
Explanation:Penicillins and the other ß-lactam antibiotics are bactericidal. They produce their antimicrobial action by preventing cross-linkage between the linear peptidoglycan polymer chains that make up the bacterial cell wall. They, therefore, inhibit cell wall synthesis.The integrity of the ß-lactam ring is essential for antimicrobial activity. Many bacteria (including most Staphylococci) are resistant to benzylpenicillin and phenoxymethylpenicillin because they produce enzymes (penicillinases, ß-lactamases) that open the ß-lactam ring.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 44
Correct
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What is the mechanism of action of captopril:
Your Answer: Angiotensin-converting enzyme inhibitor
Explanation:Captopril is an angiotensin-converting enzyme (ACE) inhibitor, which inhibits the conversion of angiotensin I to angiotensin II.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 45
Correct
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Regarding acute lymphoblastic leukaemia (ALL), which of the following statements is CORRECT:
Your Answer: 75% of cases occur before the age of 6 years.
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. There is great variation in the chance of individual patients achieving a long-term cure based on a number of biological variables. Approximately 25% of children relapse after first-line therapy and need further treatment but overall 90% of children can expect to be cured. The cure rate in adults drops significantly to less than 5% over the age of 70 years.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 46
Incorrect
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A 54-year-old woman has been visiting her GP with symptoms of tiredness, muscle weakness and headaches. She is known to be hypertensive and takes amlodipine to control this. Her blood results today show that her potassium level is low at 3.0 mmol/L, and her sodium level is slightly elevated at 146 mmol/L.Which of the following is the SINGLE most appropriate INITIAL investigation?
Your Answer: Random cortisol level
Correct Answer: Plasma renin and aldosterone levels
Explanation:Primary hyperaldosteronism occurs when there are excessive levels of aldosterone independent of the renin-angiotensin axis. Secondary hyperaldosteronism occurs due to high renin levels.The causes of primary hyperaldosteronism include:Adrenal adenoma (Conn’s syndrome) – the most common cause of hyperaldosteronism (,80% of all cases). These are usually unilateral and solitary and are more common in women.Adrenal hyperplasia – this accounts for ,15% of all cases. Usually, bilateral adrenal hyperplasia (BAH) but can be unilateral rarely. More common in men than women.Adrenal cancer – a rare diagnosis but essential not to missFamilial aldosteronism – a rare group of inherited conditions affecting the adrenal glandsThe causes of secondary hyperaldosteronism include:Drugs – diureticsObstructive renal artery disease – renal artery stenosis and atheromaRenal vasoconstriction – occurs in accelerated hypertensionOedematous disorders – heart failure, cirrhosis and nephrotic syndromePatients are often asymptomatic. When clinical features are present, the classically described presentation of hyperaldosteronism is with:HypertensionHypokalaemiaMetabolic alkalosisSodium levels can be normal or slightly raisedOther, less common, clinical features include:LethargyHeadachesMuscle weakness (from persistent hypokalaemia)Polyuria and polydipsiaIntermittent paraesthesiaTetany and paralysis (rare)Often the earliest sign of hyperaldosteronism is from aberrant urea and electrolytes showing hypokalaemia and mild hypernatraemia. If the patient is taking diuretics, and the diagnosis is suspected, these should be repeated after the patient has taken off diuretics.If the diagnosis is suspected, plasma renin and aldosterone levels should be checked. Low renin and high aldosterone levels (with a raised aldosterone: renin ratio) is suggestive of primary aldosteronism.If the renin: aldosterone ratio is high, then the effect of posture on renin, aldosterone and cortisol can be investigated to provide further information about the underlying cause of primary hyperaldosteronism. Levels should be measured lying at 9 am and standing at noon:If aldosterone and cortisol levels fall on standing, this is suggestive of an ACTH dependent cause, e.g. adrenal adenoma (Conn’s syndrome)If aldosterone levels rise and cortisol levels fall on standing, this is suggestive of an angiotensin-II dependent cause, e.g. BAHOther investigations that can help to distinguish between an adrenal adenoma and adrenal hyperplasia include:CT scanMRI scanSelective adrenal venous sampling
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 47
Correct
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Tiredness, night sweats, and easy bruising are symptoms of a 58-year-old woman. Splenomegaly is observed during the examination.Which of the following diagnoses is the SINGLE MOST LIKELY?
Your Answer: Chronic myeloid leukaemia (CML)
Explanation:CML is a myeloproliferative disorder characterised by an abnormal pluripotent haemopoietic stem cell. A cytogenetic abnormality known as the Philadelphia chromosome, which results from a reciprocal translocation between the long arms of chromosomes 9 and 22, causes more than 80% of cases of CML.CML is a disease that develops slowly over several years. This is known as the ‘chronic stage.’ This stage is usually asymptomatic, and 90 percent of patients are diagnosed at this point, with the disease being discovered frequently as a result of a routine blood test. During this stage, the bone marrow contains less than 10% immature white cells (blasts).When CML cells expand, symptoms typically begin to appear. The ‘accelerated stage’ is what it’s called. Approximately 10% of people are diagnosed at this point. During this stage, between 10% and 30% of blood cells in the bone marrow are blasts. During this stage, common clinical features include:Fatigue and exhaustionNight sweats and feverDistension of the abdomenPain in the left upper quadrant (splenic infarction)Splenomegaly (commonest examination finding)HepatomegalyBruising is simple.Gout is a type of arthritis that affects (rapid cell turnover)Hyperviscosity is a condition in which the viscosity of (CVA, priapism)A small percentage of patients experience a ‘blast crisis’ (blast stage). More than 30% of the blood cells in the bone marrow are immature blast cells at this stage. Patients with severe constitutional symptoms (fever, weight loss, bone pain), infections, and bleeding diathesis typically present at this stage.In CML, laboratory findings include:White cell count is abnormally high (often greater than 100 x 109/l).Increased number of immature leukocytes causes a left shift.Anaemia that is mild to moderately normochromic and normocytic.Platelets can be low, normal, or elevated, and the Philadelphia chromosome can be found in > 80% of patients. Serum uric acid and ALP levels are frequently elevated. Tyrosine kinase inhibitors (TKIs), such as imatinib and dasatinib, are the current mainstay of CML treatment. Allogenic bone marrow transplantation is now only used in cases where TKIs have failed to work.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 48
Incorrect
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Nitrous oxide is associated with which of the following adverse effects:
Your Answer: Laryngospasm
Correct Answer: Megaloblastic anaemia
Explanation:Exposure to nitrous oxide for prolonged periods, either by continuous or by intermittent administration, may result in megaloblastic anaemia as a result of interference with the action of vitamin B12; neurological toxic effects can occur without preceding overt haematological changes. Depression of white cell formation may also occur.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 49
Incorrect
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Which of the following best describes digoxin:
Your Answer: A positive inotrope and positive 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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Question 50
Correct
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Which of the following is NOT a typical clinical feature of sickle cell disease:
Your Answer: Neutropaenia
Explanation:Features of sickle cell disease include:Anaemia (symptoms are usually mild because the O2 dissociation curve of Hb S is shifted to the right)Vaso-occlusive crisisVisceral sequestration crisisAplastic crisisIncreased susceptibility to infectionOther clinical features: Pigment gallstones with cholecystitisChronic leg ulcersAvascular necrosis of the femoral and humeral heads or other bonesCardiomyopathyPulmonary hypertensionProliferative retinopathyPriapismRenal papillary necrosisStroke
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This question is part of the following fields:
- Haematology
- Pathology
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Question 51
Correct
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A 57-year-old male presents to the orthopaedic clinic complaining of pain and swelling in the left knee joint. On examination, the left knee is swollen, tender and erythematous. The patient is booked for joint aspiration, and a diagnosis of pseudogout is made following the aspiration. Which types of crystals would be seen in the joint aspirate to lead to this diagnosis?
Your Answer: Positively birefringent brick-shaped crystals
Explanation:Gout and pseudogout are both characterised by crystal deposition in the affected joints. The deposition of urate crystals causes gout, while calcium pyrophosphate crystals cause pseudogout. The crystals can be distinguished microscopically because urate crystals are negatively birefringent needle-shaped crystals, whilst calcium pyrophosphate crystals are positively birefringent brick-shaped crystals.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 52
Incorrect
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Digoxin is predominantly used for which of the following:
Your Answer: Termination of supraventricular tachycardia associated with Wolff-Parkinson-White syndrome
Correct Answer: Rate control in persistent and permanent atrial fibrillation
Explanation:Digoxin is most useful for controlling the ventricular response in persistent and permanent atrial fibrillation and atrial flutter. Digoxin is usually only effective for controlling the ventricular rate at rest, and should therefore only be used as monotherapy in predominantly sedentary patients with non-paroxysmal atrial fibrillation. It is now rarely used for rapid control of heart rate, as even with intravenous administration, response may take many hours. Digoxin is reserved for patients with worsening or severe heart failure due to left ventricular systolic dysfunction refractory to combination therapy with first-line agents. Digoxin is contraindicated in supraventricular arrhythmias associated with accessory conduction pathways e.g. Wolff-Parkinson-White syndrome.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 53
Incorrect
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Regarding chronic idiopathic thrombocytopaenic purpura (ITP), which of the following statements is INCORRECT:
Your Answer: The antibody in ITP is often directed against the glycoprotein IIb/IIIa or Ib complex.
Correct Answer: ITP is classically associated with massive splenomegaly.
Explanation:Chronic ITP is a relatively common disorder. The highest incidence is in women aged 15 – 50 years. It is the most common cause of thrombocytopaenia without anaemia or neutropaenia. It is usually idiopathic but it may been seen in association with other conditions. Platelet autoantibodies (usually IgG) result in the premature removal of platelets from the circulation by macrophages of the reticuloendothelial system. In many causes the antibody is directed against the glycoprotein IIb/IIIa or Ib complex. The normal platelet lifespan of 10 days is reduced to a few hours. Total megakaryocyte mass and platelet turnover are increased to approximately five times normal. Despite the destruction of platelets by splenic macrophages, the spleen is normally not enlarged. In fact, an enlarged spleen should lead to a search for other possible causes for the thrombocytopenia.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 54
Incorrect
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A 20-year-old male receives a small cut over his hand while climbing a fence causing it to bleed. Upon applying pressure for a few minutes, the bleeding stops. Which one of the following physiological components of the blood is responsible for the primary haemostasis reaction, such as in this case?
Your Answer: Activation of factor XII
Correct Answer: Platelet plug formation
Explanation:Haemostasis is your body’s defence against an injury that causes bleeding. It stops bleeding in three main steps: 1) Primary haemostasis – formation of a weak platelet plug- The primary reaction of the body is to cause local vasoconstriction at the site of injury and decrease blood flow to the affected area- the release of cytokines and inflammatory markers lead to adhesion of platelets and aggregation at the site of injury forming a platelet plug- the injured vessel wall has exposed subendothelial collagen that releases von Willebrand factor Any damage to the vessel wall causes the release of the Von Willebrand factor, which is necessary for platelet adhesion. Tissue Thromboplastin is also released, which activates the coagulation pathway, a component of secondary haemostasis. The coagulation cascade ultimately results in the conversion of fibrinogen to fibrin.2) Secondary haemostasis 3) Fibrinolysis
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 55
Correct
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A 28-year-old woman with history of blunt thoracic trauma develops hypotension chest pain, and breathlessness. A bedside echocardiogram was performed and revealed a large pericardial effusion. Due to this finding, a pericardiocentesis was to be performed.Which of the following statements is considered true regarding pericardiocentesis?
Your Answer: The needle should be aimed at the midpoint of the left clavicle
Explanation:Pericardiocentesis is a procedure done to remove fluid build-up in the sac around the heart known as the pericardium. The pericardium can be tapped from almost any reasonable location on the chest wall. However, for the usual blind pericardiocentesis, the subxiphoid approach is preferred. Ideally, 2-D echocardiography is used to guide needle insertion and the subsequent path of the needle/catheter.In the subxiphoid approach, the needle is inserted 1 cm inferior to the left xiphocostal angle with an angle of 30 degrees from the patient’s chest with a direction towards the left mid-clavicle. The fingers may sense a distinct give when the needle penetrates the parietal pericardium. Successful removal of fluid confirms the needle’s position.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 56
Correct
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An ambulance transports a 40-year-old man to the hospital. He ingested a significant amount of aspirin.In the early stages of an aspirin overdose, which form of acid-base problem should you anticipate?
Your Answer: Respiratory alkalosis
Explanation:When you take too much aspirin, you have a mix of respiratory alkalosis and metabolic acidosis. Respiratory centre stimulation produces hyperventilation and respiratory alkalosis in the early phases. The direct acid actions of aspirin tend to create a higher anion gap metabolic acidosis in the latter phases.Below summarizes some of the most common reasons of acid-base abnormalities:Respiratory alkalosis: – Hyperventilation (e.g. anxiety, pain, fever)- Pulmonary embolism- Pneumothorax- CNS disorders (e.g. CVA, SAH, encephalitis)- High altitude- Pregnancy- Early stages of aspirin overdoseRespiratory acidosis:- COPD- Life-threatening asthma- Pulmonary oedema- Respiratory depression (e.g. opiates, benzodiazepines)- Neuromuscular disease (e.g. Guillain-Barré syndrome, muscular dystrophy- Incorrect ventilator settings (hypoventilation)- ObesityMetabolic alkalosis:- Vomiting- Cardiac arrest- Multi-organ failure- Cystic fibrosis- Potassium depletion (e.g. diuretic usage)- Cushing’s syndrome- Conn’s syndromeMetabolic acidosis (with raised anion gap):- Lactic acidosis (e.g. hypoxaemia, shock, sepsis, infarction)- Ketoacidosis (e.g. diabetes, starvation, alcohol excess)- Renal failure- Poisoning (e.g. late stages of aspirin overdose, methanol, ethylene glycol)Metabolic acidosis (with normal anion gap):- Renal tubular acidosis- Diarrhoea- Ammonium chloride ingestion- Adrenal insufficiency
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 57
Incorrect
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What is the correct adrenaline dose for a patient with pulseless ventricular tachycardia?
Your Answer: 0.5 ml of 1 in 1000 adrenaline solution
Correct Answer: 10 ml of 1 in 10,000 adrenaline solution
Explanation:Ventricular fibrillation or pulseless ventricular tachycardia (VF/VT) are referred to as shockable rhythm. IV adrenaline 1 mg (10 mL of 1:10,000 solution) should be administered after 3 shocks and every 3 – 5 minutes/after alternate shocks thereafter for a shockable rhythm. For a non-shockable rhythm, 1 mg IV adrenaline should be administered as soon as IV access is obtained, and then every 3 – 5 minutes/after alternate shocks thereafter.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 58
Incorrect
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In adults, the conus medullaris of the spinal cord lies at which of the following vertebral levels:
Your Answer: T12/L1
Correct Answer: L1/L2
Explanation:At birth, the conus medullaris lies at L3. By the age of 21, it sits at L1/L2.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 59
Correct
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All of the following statements are considered true regarding likelihood ratios, except:
Your Answer: If less than one, indicates that the information increases the likelihood of the suspected diagnosis
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 60
Incorrect
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Calcium-channel blockers can be divided into two categories: dihydropyridines and non-dihydropyridines. The basic chemical structure of these two classes differs, as does their relative selectivity for cardiac versus vascular L-type calcium channels. The phenylalkylamine class and the benzothiazepine class are two subgroups of non-dihydropyridines.A phenylalkylamine calcium-channel blocker is, for example, which of the following?
Your Answer: Nifedipine
Correct Answer: Verapamil
Explanation:Calcium-channel blockers, also known as calcium antagonists, stop calcium from entering cells through the L-type calcium channel. This causes vascular smooth muscle in vessel walls to relax, resulting in a decrease in peripheral vascular resistance. They can be used for a variety of things, including:HypertensionAnginaAtrial fibrillationMigraineCalcium-channel blockers can be divided into two categories: dihydropyridines and non-dihydropyridines. The basic chemical structure of these two classes differs, as does their relative selectivity for cardiac versus vascular L-type calcium channels.Dihydropyridines have a high vascular selectivity and lower systemic vascular resistance and blood pressure. As a result, they’re frequently used to treat hypertension. Modified release formulations are also used to treat angina, but their powerful systemic vasodilator and pressure-lowering effects can cause reflex cardiac stimulation, resulting in increased inotropy and tachycardia, which can counteract the beneficial effects of reduced afterload on myocardial oxygen demand.The suffix -dpine distinguishes dihydropyridines from other pyridines. Examples of dihydropyridines that are commonly prescribed include:AmlodipineFelodipineNifedipineNimodipineThe phenylalkylamine class and the benzothiazepine class are two subgroups of non-dihydropyridines.Phenylalkylamines are less effective as systemic vasodilators because they are relatively selective for the myocardium. This group of drugs lowers myocardial oxygen demand and reverses coronary vasospasm, making them useful in the treatment of angina. They are also occasionally used to treat arrhythmias. A phenylalkylamine calcium-channel blocker like verapamil is an example.In terms of selectivity for vascular calcium channels, benzothiazepines fall somewhere between dihydropyridines and phenylalkylamines. They can lower arterial pressure without producing the same level of reflex cardiac stimulation as dihydropyridines because they have both cardiac depressant and vasodilator effects. Diltiazem is the only benzothiazepine currently in clinical use.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 61
Incorrect
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Which of the following is NOT one of the cardinal features of acute inflammation:
Your Answer: Swelling
Correct Answer: Discharge
Explanation:Classic signs:Rubor (redness)Calor (heat)Dolour (pain)Tumour (swelling)Functio laesa (loss of function)These classic signs are produced by a rapid vascular response and cellular events. The main function of these events is to bring elements of the immune system to the site of injury and prevent further tissue damage.
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This question is part of the following fields:
- Inflammatory Responses
- Pathology
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Question 62
Correct
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You contact the intensive care outreach team to inquire about a severely hypotensive resuscitated patient. They make the decision to start a dopamine infusion.Dopamine primarily has which of the following effects at high doses (>15 g/kg/min)?
Your Answer: Alpha-adrenergic stimulation
Explanation:Dopamine is a catecholamine that occurs naturally and is used to treat low cardiac output, septic shock, and renal failure. It is both adrenaline and noradrenaline’s immediate precursor.Dopamine acts on D1 and D2 dopamine receptors in the renal, mesenteric, and coronary beds at low doses (1-5 g/kg/min). Dopamine causes a significant decrease in renal vascular resistance and an increase in renal blood flow at these doses. Within this dose range, it is also involved in central modulation of behaviour and movement.Dopamine stimulates beta- and alpha-adrenergic receptors directly and indirectly at higher doses. Beta-stimulation predominates at a rate of 5-10 g/kg/min, resulting in a positive inotropic effect that increases cardiac output and coronary blood flow. Alpha-stimulation predominates at infusion rates greater than 15 g/kg/min, resulting in peripheral vasoconstriction and an increase in venous return and systolic blood pressure.Because clearance varies greatly in critically ill patients, plasma concentrations cannot be predicted reliably from infusion rates.Dopamine is given as an intravenous infusion, and because extravasation can cause tissue necrosis and sloughing, a central line is usually used (especially at higher doses >240 g/min). In an emergency, however, dopamine can be administered through a large vein (cephalic or basilic) while a central line is being prepared. Alkaline intravenous solutions inactivate it, so sodium bicarbonate should not be infused with it.The following are the most common dopamine side effects:Nausea and vomitingTachycardiaDysrhythmiasAnginaHypertension
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 63
Incorrect
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A 49-year-old woman with haemoglobin of 6 g/dL following persistent vaginal bleeding receives blood transfusion. She developed pain and burning at her cannula site and complains of a feeling of “impending doom”, nausea, and severe back pain shortly after transfusion was started. Her temperature is 38.9ºC.What is the most appropriate treatment?
Your Answer: Administer antihistamines
Correct Answer: Stop the transfusion and administer IV fluids
Explanation:Acute haemolytic transfusion reactions present with: Feeling of ‘impending doom’ as the earliest symptom, fever and chills, pain and warmth at transfusion site, nausea and vomiting, back, joint, and chest pain. Transfusion should be stopped immediately and IV fluid (usually normal saline) administered.Supportive measures and paracetamol can be given since patient has fever but it is not the immediate first step.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 64
Incorrect
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A 43 year old lady suffering with idiopathic thrombocytopenic purpura has a splenectomy. She is advised to get the Pneumococcal vaccine booster every 5 - 10 years as Streptococcus pneumoniae has which of the following properties that make her prone to infection to this organism?
Your Answer: It is alpha-haemolytic
Correct Answer: It is encapsulated
Explanation:There is a lifelong susceptibility to increased risk of infection from a variety of organisms in patients with hyposplenism, especially in children under 5 years and those with sickle cell anaemia. Patients are most susceptible is to the encapsulated bacteria Streptococcus pneumoniae, Haemophilus influenzae type B and Neisseria meningitidis. Streptococcus pneumoniae is particular concerning as it can cause rapid and fulminant disease, which can be fatal. Malaria and animal bites that become infected also tend to be more severe.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 65
Incorrect
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Which of the following statement is correct with regards to the female urethra?
Your Answer: The urethra is longer in women than it is in men.
Correct Answer: The urethra opens in the vestibule that lies between the labia minora.
Explanation:The urethra in women is short (about 4 cm long), and begins at the base of the bladder. Its course runs inferiorly through the urogenital diaphragm, then into the perineum. It then opens in the vestibule which lies between the labia minora. The inferior aspect of the urethra is bound to the anterior surface of the vagina. The urethral opening is anterior to the vaginal opening in the vestibule. As the urethra passes through the pelvic floor, it is surrounded by the external urethral sphincter.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 66
Incorrect
-
All of the following are indications for beta-blockers EXCEPT for:
Your Answer: Essential tremor
Correct Answer: Prinzmetal's angina
Explanation:Beta-blockers are contraindicated in Prinzmetal’s angina.Beta-blockers may be indicated in:HypertensionPheochromocytoma (only with an alpha-blocker)AnginaSecondary prevention after ACSArrhythmias including atrial fibrillationHeart failureThyrotoxicosisAnxietyProphylaxis of migraineEssential tremorGlaucoma
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 67
Incorrect
-
A 10-year-old girl that appears systemically well presents with a honey-crusted scab close to the corner of her mouth and states that the area is slightly itchy but not painful. The diagnosis given was impetigo.What is most likely the mode of transmission of the causative agent of the said diagnosis?
Your Answer: Indirect contact
Correct Answer: Direct contact
Explanation:Impetigo is a common pyoderma that is most often seen in children. Historically, most cases were caused by group A streptococci (GAS; Streptococcus pyogenes), although S. aureus has become the predominant pathogen over the last 15 years.A bullous form of impetigo accounts for approximately 10% of cases. It is caused by strains of S. aureus that produce exfoliative toxins leading to the formation of bullae, which quickly rupture and form a transparent, light brown crust.Impetigo is spread mainly by person-to-person contact; it is rapidly spread through direct transmission. The diagnosis of impetigo can be made from a Gram stain and culture of the vesicular contents.
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 68
Incorrect
-
Eosinophils comprise what percentage of circulating white cells:
Your Answer: 6 - 10%
Correct Answer: 1 - 3%
Explanation:Eosinophils comprise 1 – 3% of circulating white cells. Eosinophils are similar to neutrophils, except that the cytoplasmic granules are coarser and more deeply red staining, and there are rarely more than three nuclear lobes. They are less motile, but longer lived. They enter inflammatory exudates and have a special role in allergic responses, defence against parasites and removal of fibrin formed during inflammation. Thus they play a role in local immunity and tissue repair.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 69
Incorrect
-
Capillaries are designed with a small diffusion distance for nutrition and gaseous exchange with the tissues they serve. Capillaries come in a variety of shapes and sizes, each with its own function in transcapillary exchange.Which of the following types of capillaries is the least permeable in the human body?
Your Answer: Incomplete capillaries
Correct Answer: Continuous capillaries
Explanation:Capillaries are designed with a small diffusion distance for nutrition and gaseous exchange with the tissues they serve. Because oxygen and carbon dioxide are both highly soluble in lipids (lipophilic), they can easily diffuse along a concentration gradient across the endothelial lipid bilayer membrane. In contrast, glucose, electrolytes, and other polar, charged molecules are lipid-insoluble (hydrophilic). These chemicals are unable to pass through the lipid bilayer membrane directly and must instead travel through gaps between endothelial cells.Capillaries are divided into three types: continuous, fenestrated, and sinusoidal. Each of these capillary types contains different sized gaps between the endothelial cells that operate as a filter, limiting which molecules and structures can pass through.The permeability of capillaries is affected by the wall continuity, which varies depending on the capillary type.Skeletal muscle, myocardium, skin, lungs, and connective tissue all have continuous capillaries. These capillaries are the least permeable. They have a basement membrane and a continuous layer of endothelium. The presence of intercellular spaces allows water and hydrophilic molecules to pass across. Tight connections between the cells and the glycocalyx inhibit passage via these gaps, making diffusion 1000-10,000 times slower than for lipophilic compounds. The diffusion of molecules larger than 10,000 Da, such as plasma proteins, is likewise prevented by this narrow pore system. These big substances can pass through the capillary wall, but only very slowly, because endothelial cells have enormous holes.The kidneys, gut, and exocrine and endocrine glands all have fenestrated capillaries. These are specialized capillaries that allow fluid to be filtered quickly. Water, nutrients, and hormones can pass via windows or fenestrae in their endothelium, which are connected by a thin porous membrane. They are ten times more permeable than continuous capillaries due to the presence of these fenestrae. Fenestrated capillaries have a healthy basement membrane.The spleen, liver, and bone marrow all have sinusoidal capillaries, also known as discontinuous capillaries. Their endothelium has huge gaps of >100 nm, and their basement membrane is inadequate. They are highly permeable as a result, allowing red blood cells to travel freely.
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This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
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Question 70
Incorrect
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You are teaching a group of medical students about cardiovascular examination. You are discussing heart sounds and the cardiac cycle. Which of the following stages of the cardiac cycle occurs immediately after the aortic valve closes:
Your Answer: Isovolumetric contraction
Correct Answer: Isovolumetric relaxation
Explanation:Immediately after the closure of the semilunar valves, the ventricles rapidly relax and ventricular pressure decreases rapidly but the AV valves remain closed as initially the ventricular pressure is still greater than atrial pressure. This is isovolumetric relaxation. Atrial pressure continues to rise because of venous return, with the v wave of the JVP waveform peaking during this phase. Rapid flow of blood from the atria into the ventricles during the ventricular filling phase causes thethird heart sound, which is normal in children but, in adults, is associated with disease such as ventricular dilation.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 71
Incorrect
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Regarding flucloxacillin, which of the following statements is CORRECT:
Your Answer: It is used first line for empirical treatment of infective endocarditis.
Correct Answer: It is resistant to bacterial beta-lactamases.
Explanation:Flucloxacillin is unique in that it is beta-lactamase stable and it can be used in infections caused by beta-lactamase producing staphylococci e.g. S. aureus. It is acid-stable and can therefore be given by mouth as well as by injection. It is used first line for treatment of widespread impetigo infection, cellulitis, mastitis, osteomyelitis, septic arthritis, severe erysipelas, severe/spreading otitis externa and infective endocarditis caused by staphylococci. The most common adverse effects of flucloxacillin include nausea, vomiting, skin rash, and diarrhoea. Cholestatic jaundice and hepatitis may occur very rarely, up to two months after treatment with flucloxacillin has been stopped. Administration for more than 2 weeks and increasing age are risk factors. First line treatment of animal and human bites is co-amoxiclav.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 72
Incorrect
-
A 29 year old patient with known inflammatory bowel disease presents to ED with surgical complications following his recent ileocaecal resection. Removal of the terminal ileum may result in the malabsorption of which of the following:
Your Answer: Folate
Correct Answer: Vitamin B12
Explanation:On ingestion, vitamin B12 is bound to R protein found in saliva and gastric secretions, which protects it from digestion in the stomach. Intrinsic factor is secreted by gastric parietal cells. Receptors for the IF-B12 complex are present in the membrane of epithelial cells of the terminal ileum, which bind the complex and allow uptake of vitamin B12 across the apical membrane by endocytosis. Vitamin B12 is then transported across the basal membrane into the portal blood where it is bound to transcobalamin II and processed by the liver. In pernicious anaemia, there are autoantibodies against gastric parietal cells and intrinsic factor, resulting in vitamin B12 deficiency anaemia.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 73
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 74
Incorrect
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Which of the following ions is more abundant in extracellular fluid than in intracellular fluid:
Your Answer: Mg 2+
Correct Answer: Cl -
Explanation:Protein and phosphate are the primary intracellular anions, while chloride (Cl-) and bicarbonate are the predominant extracellular anions (HCO3-).
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 75
Correct
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As a response to low blood pressure, the baroreceptor reflex will facilitate vasoconstriction by activating which receptor?
Your Answer: Alpha1
Explanation:The rate of baroreceptor firing slows down when blood pressure falls too low. This causes an increase in sympathetic stimulation of the heart, resulting in an increase in cardiac output. It also causes vasoconstriction by activating alpha 1 receptors in smooth muscle, which causes sympathetic stimulation of peripheral vessels. Alpha2 receptors can be found in both the brain and the peripheral nervous system. They control sympathetic outflow in the brain stem. Beta1 receptors, which are found on the cell membrane of cardiac muscle cells, stimulate heart rate and myocardial contractility. The smooth muscle cell membrane contains beta2 receptors, which promote smooth muscle relaxation in the lungs causing bronchodilation, GI tract, and peripheral blood vessels.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 76
Correct
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Which of the following drugs decreases plasma-theophylline levels:
Your Answer: Carbamazepine
Explanation:Examples of enzyme-inhibiting drugs (raise plasma theophylline level):ErythromycinClarithromycinCiprofloxacinFluconazoleVerapamilAllopurinolCimetidineExamples of enzyme-inducing drugs (lower plasma theophylline level):PrimidonePhenobarbitalCarbamazepinePhenytoinRitonavirRifampicinSt John’s Wort
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 77
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 78
Incorrect
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Which of the following is NOT a typical clinical feature of diabetic ketoacidosis:
Your Answer: Dry mucous membrane
Correct Answer: Cheyne–Stokes respiration
Explanation:Clinical features of DKA: Symptoms: Polyuria, polydipsia, thirst, lethargy, weight loss, nausea, vomiting, anorexia, abdominal pain, dehydration, headache, altered mental stateSigns: Dry mucous membranes, ketotic breath, tachycardia, hypotension, Kussmaul breathing, focal signs of precipitant e.g. infection
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 79
Correct
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A 25-year-old girl just got back from a trip to Northern India. She complains of headaches and intermittent fever. The fever starts with intense chills, then feels very hot, followed by profuse sweating. She is drowsy and is running a fever of 39.0°C. On examination, there are no palpable lymph nodes or rash seen. She has hepatosplenomegaly. Which one of the following is the most likely diagnosis?
Your Answer: Malaria
Explanation:Malaria is a protozoal infection of red blood cells and the liver. It is caused by the parasite belonging to the genus Plasmodium. It is transmitted by the female mosquito Anopheles.Several species with distinct features:P. vivax/P. ovaleP. malariaeP. falciparumThe common symptoms of malaria are:Paroxysms of fever – a cyclical occurrence of:1) a cold phase – the patient experiences intense chills2) a hot stage – the patient feels extremely hot3) a sweating stage – the fever declines and the patient sweats profusely- Fever recurs at regular intervals (48hrs, 72hrs): Variable by species of PlasmodiumAnaemia (RBC infection)- Severity varies by species of Plasmodium- Haemolytic: sometimes jaundiceSplenomegalyAlso nonspecific symptoms:- Sweating- fatigue- malaise- arthralgias- headache- Sometimes cough, vomiting, diarrhoea
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 80
Incorrect
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Identify the type of graph described below:A graph that consists of a vertical bar graph in which values are plotted in decreasing order of relative frequency from left to right. The independent variables on the chart are shown on the horizontal axis and the dependent variables are portrayed as the heights of bars.
Your Answer: Forest plot
Correct Answer: Pareto diagram
Explanation:A pareto diagram, or pareto chart, consists of a vertical bar graph in which values are plotted in decreasing order of relative frequency from left to right. The independent variables on the chart are shown on the horizontal axis and the dependent variables are portrayed as the heights of bars.A point-to-point graph, which shows the cumulative relative frequency, may be superimposed on the bar.Because the values of the statistical variables are placed in order of relative frequency, the graph clearly reveals which factors have the greatest impact and where attention is likely to yield the greatest benefit. It is extremely useful for analysing what problems need attention first, because the taller bars on the chart clearly illustrate which variable have the greatest cumulative effect on a given system.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 81
Incorrect
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You have been called to review a patient and his management in the resuscitation room. A very sick patient has been started on mannitol in his treatment protocol. Out of the following, what is NOT an FDA-recognized indication for the use of mannitol?
Your Answer: Glaucoma
Correct Answer: Congestive cardiac failure
Explanation:Mannitol is the most widely used osmotic diuretic that is most commonly used to reduce cerebral oedema and intracranial pressure. Mannitol has four FDA approved uses clinically:1. Reduction of intracranial pressure and brain mass2. reduce intraocular pressure if this is not achievable by other means3. promote diuresis for acute renal failure to prevent or treat the oliguric phase before irreversible damage4. promote diuresis to promote the excretion of toxic substances, materials, and metabolitesIt can be used in rhabdomyolysis-induced renal failure, especially in crush injuries. Mannitol reduces osmotic swelling and oedema in the injured muscle cells and helps restore skeletal muscle function. It is a low molecular weight compound and can be freely filtered at the glomerulus and not reabsorbed. This way increases the osmolality of the glomerular filtrate and tubular fluid, increasing urinary volume by an osmotic effect. It also does not cross the blood-brain barrier (BBB).Mannitol causes an expansion of the extracellular fluid space, which may worsen congestive cardiac failure. Contraindications to the use of mannitol include:1. Anuria due to renal disease2. Acute intracranial bleeding (except during craniotomy)3. Severe cardiac failure4. Severe dehydration5. Severe pulmonary oedema or congestion6. Known hypersensitivity to mannitol
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 82
Incorrect
-
Which of the following muscles is most responsible for thigh extension at the hip joint?
Your Answer: Quadriceps femoris and gluteus maximus
Correct Answer: Hamstrings and gluteus maximus
Explanation:For hip extension, the gluteus maximus and hamstring muscles work together. To compensate for gluteus maximus weakness, the hamstring frequently acts as the primary hip extensor.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 83
Incorrect
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In the resus area of your Emergency Department, you are called to a VF cardiac arrest.During an adult VF arrest, which of the following points should be treated with adrenaline?
Your Answer: As soon as circulatory access is obtained
Correct Answer: After the 3 rd shock, once chest compressions have been resumed
Explanation:In non-shockable (PEA/asystole) cardiac arrests, adrenaline should be given as soon as circulatory access is gained. The dose is 1 mg via IV or IO (10 mL of 1:10,000 or 1 mL of 1:1000).Once chest compressions have been resumed after the third shock in a shockable (Vf/pVT) cardiac arrest, adrenaline should be administered. The dosage is one milligram (10 mL of 1:10,000 or 1 mL of 1:1000)It should be given every 3-5 minutes after that (i.e. alternate loops) and without interrupting chest compressions.Systemic vasoconstriction is caused by the alpha-adrenergic effects of adrenaline, which raises coronary and cerebral perfusion pressures.Adrenaline’s beta-adrenergic effects are inotropic (increased myocardial contractility) and chronotropic (increased heart rate), and they can increase coronary and cerebral blood flow. However, concomitant increases in myocardial oxygen consumption and ectopic ventricular arrhythmias (especially in the absence of acidaemia), transient hypoxemia due to pulmonary arteriovenous shunting, impaired microcirculation, and increased post-cardiac arrest myocardial dysfunction may offset these benefits.Although there is no evidence of long-term benefit from its use in cardiac arrest, the improved short-term survival reported in some studies justifies its use.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 84
Incorrect
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A young farmer who is caught under farm machinery and suffering from a major crush injury is taken to the emergency department and requires a quick induction sequence. In this type of injury, which of the following anaesthetic medicines should be avoided?
Your Answer: Thiopental
Correct Answer: Suxamethonium
Explanation:Suxamethonium is a neuromuscular blocker. It is contraindicated in patients who have experienced massive trauma, hyperkalemic, or burn injuries.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 85
Incorrect
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Regarding skeletal muscle, which of the following best describes the Z-line:
Your Answer: A line dividing myofibrils into myofilaments
Correct Answer: A line dividing muscle fibres into sarcomeres
Explanation:Each muscle fibre is divided at regular intervals along its length into sarcomeres separated by Z-lines. The sarcomere is the functional unit of the muscle.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 86
Incorrect
-
A 32-old woman comes for a follow-up visit after being discharged on medications for her newly diagnosed epilepsy. She now complains of a tremor in her arm when she holds a tray in her hand. You examine the patient and notice she has developed postural tremors. Which of the following medications for epilepsy is most likely responsible for this tremor?
Your Answer: Phenytoin
Correct Answer: Sodium valproate
Explanation:A postural tumour is observed when a person maintains a position against gravity, such as holding the arms outstretched. (The patient holding her tray against gravity) Sodium valproate is the most commonly prescribed medication for epilepsy. It is commonly associated with tremors as valproate-induced tremors occur in around 6-45% of patients. The tremors are commonly postural, but a resting tremor may also occur.Approximately 25% of patients taking sodium valproate are found to develop a tremor within 3-12 months of initiating therapy.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 87
Incorrect
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Regarding NSAIDs, which of the following statements is CORRECT:
Your Answer: Mefenamic acid has very potent anti-inflammatory properties.
Correct 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 88
Correct
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A 36-year-old woman is 22-weeks pregnant and is investigated for a possible thyroid disorder. When her total thyroid hormone levels does not correlate with her thyrometabolic status, her thyroid-binding globulin levels are checked.What percentage of circulating thyroid hormones is bound to thyroid-binding globulin?
Your Answer: 70%
Explanation:Only a very small fraction of the thyroid hormones circulating in the blood are free. The majority is bound to transport proteins. Only the free thyroid hormones are biologically active, and measurement of total thyroid hormone levels can be misleading. The relative percentages of bound and unbound thyroid hormones are:Bound to thyroid-binding globulin -70%Bound to albumin -15-20%Bound to transthyretin -10-15%Free T3 -0.3%Free T4 -0.03%
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 89
Incorrect
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Which of the following drugs used in the management of hyperkalaemia does not affect serum potassium levels:
Your Answer: Calcium resonium
Correct Answer: Calcium gluconate
Explanation:Calcium gluconate is given to antagonise cardiac cell membrane excitability to reduce the risk of arrhythmias. It has no effect on serum potassium levels unlike the alternative drugs listed above.
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This question is part of the following fields:
- Fluids And Electrolytes
- Pharmacology
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Question 90
Incorrect
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C-reactive protein (CRP) synthesis is predominantly stimulated by which of the following cytokines:
Your Answer: IL-5
Correct Answer: IL-6
Explanation:Activated leukocytes, adipocytes, and endothelial cells all release interleukin 6 (IL-6), a significant proinflammatory cytokine. The main downstream mediator of the acute phase response is C-reactive protein, which is predominantly produced by IL-6–dependent hepatic biosynthesis.
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This question is part of the following fields:
- Inflammatory Responses
- Pathology
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Question 91
Incorrect
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Regarding hepatitis A, which of the following statements is CORRECT:
Your Answer: Patients only become infective once symptomatic.
Correct 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 92
Incorrect
-
A 62-year-old female complains of pain in her right upper quadrant. An abdominal ultrasound is conducted, and a big gallstone is discovered. The radiologist who performs the scan speaks with you about the physiology of the gallbladder and biliary tract.During a 24-hour period, how much bile does the gallbladder produce?
Your Answer: 200-400 ml
Correct Answer: 400-800 ml
Explanation:The gallbladder stores and concentrates bile, which is produced by the liver. In a 24-hour period, around 400 to 800 mL of bile is generated. The breakdown of fats into fatty acids, the removal of waste materials, and cholesterol homeostasis are all crucial functions of bile.Bile is created on a constant basis, however it is only necessary after a meal has been consumed. The elimination of water and ions concentrates bile in the gallbladder, which is subsequently stored for later use. Food induces the release of the hormone cholecystokinin from the duodenum, the contraction of the gallbladder, and the relaxation of the sphincter of Oddi. The bile then enters the duodenum.Bile acids have a hydrophobic and hydrophilic area, making them amphipathic. Bile acids’ amphipathic nature allows them to perform the following crucial functions:Emulsification of lipid aggregates increases the surface area of fat and makes it easier for lipases to digest it.Lipid solubilization and transport: solubilizes lipids by creating micelles, which are lipid clumps that float in water.
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This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 93
Incorrect
-
Approximately what percentage of filtered bicarbonate is reabsorbed in the proximal tubule:
Your Answer: 0.5
Correct Answer: 0.8
Explanation:Bicarbonate is freely filtered at the glomerulus. Less than 0.1% of filtered bicarbonate is normally excreted in the urine (if plasma [HCO3-] increases, maximum tubular transport is exceeded and some HCO3-is excreted in urine). About 80% of bicarbonate is reabsorbed in the proximal tubule. For each H+secreted into the lumen, one Na+and one HCO3-are reabsorbed into the plasma. H+is recycled so there is little net secretion of H+at this stage. A further 10 – 15% of HCO3-is similarly reabsorbed in the thick ascending limb of the loop of Henle. In the early distal tubule, H+secretion is predominantly by Na+/H+exchange but more distally, the Na+gradient is insufficient so secretion is via H+ATPase and H+/K+ATPase in intercalated cells, which contain plentiful carbonic acid. As secreted H+is derived from CO2, new HCO3-is formed and returns to the blood.H+secretion is proportional to intracellular [H+] which itself is related to extracellular pH. A fall in blood pH will therefore stimulate renal H+secretion. In the proximal tubule secretion of H+serves to reclaim bicarbonate from glomerular filtrate so it is not lost, but in the distal nephron, secretion leads to net acid excretion and generation of new bicarbonate.
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This question is part of the following fields:
- Physiology
- Renal
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Question 94
Correct
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While on morning rounds in the medical ward, the attending physician asks a medical student about the differences between transudates and exudates and their causes. The student explains that a transudate is an excess fluid that leaks out of an intravascular compartment due to an imbalance between oncotic and hydrostatic pressures. Which ONE of the following conditions will he mention as the cause of a transudate?
Your Answer: Meig’s syndrome
Explanation:Transudative effusions are caused due to systemic causes leading to increased hydrostatic pressure or decreased oncotic pressure. These include:1) Meig’s Syndrome (Ovarian tumour causing ascites and pleural effusion)2) Congestive heart failure3) Nephrotic Syndrome4) Myxoedema5) Cirrhosis6) SarcoidosisAn exudate is caused by local inflammation and results from increased vascular permeability. Causes include:1) Rheumatoid arthritis2) Pneumonia leading to empyema3) Malignancies4) Pericarditis
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 95
Incorrect
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What is the main mechanism of action of metoclopramide:
Your Answer: Dopamine agonist
Correct Answer: Dopamine antagonist
Explanation:Metoclopramide is a dopamine-receptor antagonist. Blockade of inhibitory dopamine receptors in the GI tract may allow stimulatory actions of ACh at muscarinic synapses to predominate. Metoclopramide also blocks dopamine D2-receptors within the chemoreceptor trigger zone (CTZ). At high doses, it is also thought to have some 5-HT3antagonist activity.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 96
Incorrect
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A patient is complaining of painless jaundice. His bilirubin levels are abnormally high.Which of the following statements about bile is correct?
Your Answer: It is produced in the gallbladder
Correct Answer: Bile acids are amphipathic
Explanation:The liver produces bile on a constant basis, which is then stored and concentrated in the gallbladder. In a 24-hour period, around 400 to 800 mL of bile is generated.Bile is involved in the following processes:Fats are broken down into fatty acids.Waste products are eliminated.Cholesterol homeostasis is the balance of cholesterol in the body.The enteric hormones cholecystokinin and secretin are primarily responsible for bile secretion. When chyme from an unprocessed meal enters the small intestine, they are released, and they play the following function in bile secretion and flow:Cholecystokinin promotes gallbladder and common bile duct contractions, allowing bile to reach the intestine.Secretin enhances the secretion of bicarbonate and water by biliary duct cells, increasing the amount of bile and its flow into the gut.Bile acids have a hydrophobic and hydrophilic area, making them amphipathic. Bile acids’ amphipathic nature allows them to perform the following crucial functions:Emulsification of lipid aggregates increases the surface area of fat and makes it easier for lipases to digest it.Lipid solubilization and transport: solubilizes lipids by creating micelles, which are lipid clumps that float in water.
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This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 97
Incorrect
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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: Chronic lymphocytic leukaemia
Correct 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 98
Correct
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What is the main mechanism of action of dopamine as an inotropic sympathomimetic:
Your Answer: Beta1-receptor agonist
Explanation:Dopamine is a neurotransmitter and a metabolic precursor of the catecholamines. It acts on beta1-receptors in cardiac muscle increasing cardiac contractility, and increases renal perfusion by stimulating dopamine receptors in the renal vasculature. This is of benefit in cardiogenic shock where deterioration of renal function is common.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 99
Incorrect
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A 69-year-old woman with new-onset back pain was diagnosed with osteopenia, osteolytic lesions, and vertebral collapse after undergoing a radiographic examination. Her laboratory results revealed anaemia and hypercalcemia. These findings most likely indicate what condition?
Your Answer: Acute myeloid leukaemia
Correct Answer: Myeloma
Explanation:Bone pain, pathologic fractures, weakness, anaemia, infection, hypercalcemia, spinal cord compression, and renal failure are all signs and symptoms of multiple myeloma (MM). The patient’s condition matched the signs and symptoms of myeloma.
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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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Regarding calcium handling by the kidneys, which of the following statements is CORRECT:
Your Answer: About 50% of filtered Ca 2+ is reabsorbed passively in the loop of Henle.
Correct Answer: Activated vitamin D upregulates Ca 2+ ATPase pumps in the distal tubule.
Explanation:Calcium that is not protein bound is freely filtered in the glomerulus, and there is reabsorption along the nephron.About 70% is reabsorbed in the proximal tubule.About 20% is reabsorbed in the thick ascending limb of the loop of Henle.This reabsorption is mainly passive and paracellular and driven by sodium reabsorption. Sodium reabsorption causes water reabsorption, which raises tubular calcium concentration, causing calcium to diffuse out of the tubules. The positive lumen potential also encourages calcium to leave the tubule.About 5 – 10% is reabsorbed in the distal convoluted tubule.Less than 0.5% is reabsorbed in the collecting ducts.Calcium reabsorption in the distal nephron is active and transcellular and is the major target for hormonal control.Calcium homeostasis is primarily controlled by three hormones: parathyroid hormone, activated vitamin D and calcitonin.Parathyroid hormone acts on the kidneys to increase calcium reabsorption in the distal tubule by activating Ca2+entry channels in the apical membrane and the Ca2+ATPase pump in the basolateral membrane (and to decrease phosphate reabsorption in the proximal tubule).Activated vitamin D acts to increase calcium reabsorption in the distal tubule via activation of a basolateral Ca2+ATPase pump (and to increase phosphate reabsorption).Calcitonin acts to inhibit renal reabsorption of calcium (and phosphate).
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This question is part of the following fields:
- Physiology
- Renal
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Question 101
Incorrect
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The pelvic bone is formed by which of the following:
Your Answer: Iliac crest and pubic ramus
Correct Answer: Ilium, ischium and pubis
Explanation:Each pelvic bone is formed by three elements: the ilium (superiorly), the pubis (anteroinferiorly) and the ischium (posteroinferiorly).
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 102
Correct
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Which of the following side effects is most likely caused by erythromycin:
Your Answer: QT - prolongation
Explanation:The side effects of erythromycin include abdominal pain, anaphylaxis, cholestatic hepatitis, confusion, diarrhoea, dyspepsia, fever, flatulence, hallucinations, hearing loss, headache, hypertrophic pyloric stenosis, hypotension, Interstitialnephritis, mild allergic reactions, nausea, nervous system effects,including seizures, pain, pruritus, pseudomembranous colitis, QT prolongation, rash, skin eruptions, tinnitus, urticaria, ventricular arrhythmias, ventricular tachycardia, vertigo, vomiting
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 103
Incorrect
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Question 104
Incorrect
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A 30-year-old woman with type 1 diabetes mellitus is brought in drowsy and confused. Her BM is 2.2 mmol/l and a dose of IM glucagon is administered.What is the principal stimulus for the secretion of glucagon?
Your Answer: Acetylcholine
Correct Answer: Hypoglycaemia
Explanation:Glucagon, a peptide hormone, is produced and secreted by alpha cells of the islets of Langerhans, located in the endocrine portion of the pancreas. Its main physiological role is stimulation of hepatic glucose output leading to increase in blood glucose. It is the major counter-regulatory hormone to insulin in maintaining glucose homeostasis.The principal stimulus for the secretion of glucagon is hypoglycaemia. Hypoglycaemia then stimulates:GlycogenolysisGluconeogenesisLipolysis in adipose tissue leading to increased glycaemia.Secretion of glucagon is also stimulated by arginine, alanine, adrenaline, acetylcholine and cholecystokininSecretion of glucagon is inhibited by:InsulinSomatostatinIncreased free fatty acidsIncreased urea production
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 105
Incorrect
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A 29-year-old male presents with a 3-day history of bloody diarrhoea and abdominal pain.All the following are causes of infectious bloody diarrhoea EXCEPT?
Your Answer: Salmonella enterica
Correct Answer: Enterotoxigenic Escherichia coli
Explanation:Infective causes of bloody diarrhoea include:Salmonella sppCampylobacter sppSchistosomiasisEntamoeba histolytica (Amoebiasis )Shigella sppClostridium difficileYersinia sppEnteroinvasive Escherichia coliEnterotoxigenic Escherichia coli is non-invasive and does not cause inflammation of the gut and bloody diarrhoea. It presents with copious watery diarrhoea and usually are not associated with abdominal cramping.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 106
Incorrect
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A patient presents with a history of excessive thirst, urination and high fluid intake. His blood sugar is normal. You estimate his osmolarity as part of his work-up.Which of these equations can be used to estimate osmolarity?
Your Answer: 3 (Na + ) + 2 (K + ) + Glucose + Urea
Correct Answer: 2 (Na + ) + 2 (K + ) + Glucose + Urea
Explanation:Osmolality and osmolarity are measurements of the solute concentration of a solution. Although the two terms are often used interchangeably, there are differences in the definitions, how they are calculated and the units of measurement used.Osmolarity, expressed as mmol/L, is an estimation of the osmolar concentration of plasma. It is proportional to the number of particles per litre of solution.Measured Na+, K+, urea and glucose concentrations are used to calculate the value indirectly.It is unreliable in pseudohyponatremia and hyperproteinaemia.The equations used to calculate osmolarity are:Osmolarity = 2 (Na+) + 2 (K+) + Glucose + Urea (all in mmol/L)OROsmolarity = 2 (Na+) + Glucose + Urea (all in mmol/L)Doubling of sodium accounts for the negative ions associated with sodium, and the exclusion of potassium approximately allows for the incomplete dissociation of sodium chloride.
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 107
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 absolute risk in the warfarin group is 0.1
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 108
Incorrect
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Which of the following statements regarding the infectivity periods of these corresponding diseases is correct?
Your Answer: Measles is infectious for 10 days after the rash appears
Correct Answer: Rubella is infectious until 5 days after the rash appears
Explanation:Rubella can be contagious from 7 days before to 7 days after the rash appears.Patients with measles are contagious from 1-2 days before the onset of symptoms.A person with chickenpox is considered contagious beginning 1 to 2 days before rash onset until all the chickenpox lesions have crusted (scabbed). The infectious period of mumps is considered from 2 days before to 5 days after parotitis onset.Hepatitis A is highly transmissible and has an average incubation period of 28 to 30 days (range 15–50 days). The maximum infectivity is during the second half of the incubation period (i.e. while asymptomatic) and most cases are considered non-infectious after the first week of jaundice.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 109
Incorrect
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A 20-year-old male patient lives in a travelling community and has never received any vaccinations. He presents to you with fever.Which of these statements concerning indications and contraindications for vaccination is FALSE?
Your Answer: Vaccination is contraindicated if there has been a confirmed anaphylactic reaction to a previous dose of a vaccine containing the same antigens
Correct Answer: Premature infants should have the their immunisation schedule adjusted for gestational age
Explanation:All vaccines are contraindicated in individuals with:A confirmed anaphylactic reaction to a previous dose of the vaccine or a vaccine containing the same antigens.A confirmed anaphylactic reaction to a component in the vaccine e.g. neomycinLive attenuated vaccines are contraindicated in pregnancy except in cases where risk of infection is more than the risks of vaccination.During times of acute febrile illness, vaccination should be avoided.12 weeks should elapse after a dose of human immunoglobulin before a live vaccine is administered.The normal times recommended for immunization of full-term babies should also be applied to premature infants and correction for gestational age should NOT be implemented.
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 110
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 111
Incorrect
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How is filtered K+mainly reabsorbed in the thick ascending limb of the loop of Henle:
Your Answer: Primary active transport via K + /H + ATPase
Correct Answer: Secondary active transport via Na + /K + /2Cl - cotransporter
Explanation:Around 30% of filtered K+is reabsorbed in the thick ascending limb of the loop of Henle, primarily via the luminal Na+/K+/2Cl-cotransporter, but there is also significant paracellular reabsorption, encouraged by the positive potential in the tubular lumen.
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This question is part of the following fields:
- Physiology
- Renal
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Question 112
Incorrect
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Intravenous glucose solutions are typically used in the treatment of all of the following situations except:
Your Answer: Routine fluid maintenance in patients who are nil by mouth
Correct Answer: Hypokalaemia
Explanation:In hypokalaemia, initial potassium replacement therapy should not involve glucose infusions, as glucose may cause a further decrease in the plasma-potassium concentration. Glucose infusions are used for the other indications like diabetic ketoacidosis, hypoglycaemia, routine fluid maintenance in patients who are nil by mouth (very important in children), and in hyperkalaemia.
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This question is part of the following fields:
- Fluids And Electrolytes
- Pharmacology
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Question 113
Incorrect
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Regarding the routine childhood immunisation schedule, which of the following vaccines is given to preschool children (aged 3 years and 4 months):
Your Answer: Pneumococcal conjugate vaccine (PCV)
Correct Answer: Measles, mumps and rubella (MMR)
Explanation:The current UK childhood immunisation schedule is as follows:8 weeks:DTaP/IPV(polio)/Hib/Hep B (diptheria, tetanus, pertussis, polio,Haemophilus influenzatype b and hepatitis B) – 6-in-one injection (Infranix hexa);plus:Rotavirus gastroenteritis (Rotarix) – oral route (drops)Meningitis B (Bexsero)12 weeks:DTaP/IPV(polio)/Hib/Hep B – 2nddose: 6-in-one injection, 2nddose (Infranix hexa);plus:PCV (pneumococcal conjugate vaccine) – in a separate injection (Prevenar 13)Rotavirus gastroenteritis 2nddose (Rotarix) – oral route (drops)16 weeks:DTaP/IPV(polio)/Hib/Hep B – 3rddose: 6-in-one injection, 3rddose (Infranix hexa);plus:Meningitis B 2nddose (Bexsero)Between 12 and 13 months:Hib/Men C (combined as one injection) – 4th dose of Hib and 1stdose of Meningitis C (Menitorix);plus:MMR (measles, mumps and rubella) – combined as one injection (Priorix or M-M-RVAXPRO);plus:PCV (pneumococcal conjugate vaccine) – 2nddose in a separate injection (Prevenar 13);plus:Meningitis B 3rddose (Bexsero)From 2 to end of primary school:Nasal flu spray (Fluenz Tetra). For children aged 2,3 and 4, this is usually given in the GP surgery. Children in school years 1,2 and 3 may have this at school.3 years and 4 months:Pre-school booster of DTaP/IPV (polio) – 4-in-one injection (Repevax or Infanrix-IPV);plus:MMR – 2nd dose (Priorix or M-M-RVAXPRO) – in a separate injectionBetween 12 and 13 years:HPV (human papilloma virus types 6,11, 16 and 18) –twoinjections of Gardasil given. The second injection is given 6-24 months after the first one.14 years:Td/IPV (polio) booster – 3-in-one injection (Revaxis)Men ACWY: combined protection against meningitis A, C, W and Y (Nimenrix or Menveo)The BCG vaccination against tuberculosis is only offered to neonates in high-risk areas or with high-risk backgrounds. When required it is usually given before leaving the hospital soon after birth.
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This question is part of the following fields:
- Immunoglobulins And Vaccines
- Pharmacology
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Question 114
Correct
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All of the following are indications for beta-blockers EXCEPT for:
Your Answer: Raynaud's disease
Explanation:Beta-blockers are contraindicated in Raynaud’s syndrome. Beta-blockers may be indicated in:HypertensionPheochromocytoma (only with an alpha-blocker)AnginaSecondary prevention after ACSArrhythmias including atrial fibrillationHeart failureThyrotoxicosisAnxietyProphylaxis of migraineEssential tremorGlaucoma
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 115
Incorrect
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You're taking a history of a 59-year-old banker who has had heartburn in the past.Which of the following information about antacids is correct?
Your Answer: Aluminium hydroxide is relatively water-soluble
Correct Answer: Magnesium carbonate can reduce the absorption of drugs taken at the same time
Explanation:Antacids such as aluminium hydroxide and magnesium carbonate are commonly used. They’re both water-insoluble and can reduce the absorption of drugs taken together. Allow at least 1-2 hours between taking these antacids and any other medications.Because it reduces gastrointestinal phosphate absorption, aluminium hydroxide can also be used to treat hyperphosphatemia in patients with renal failure.Magnesium carbonate has a laxative effect, whereas aluminium hydroxide has a constipating effect.
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This question is part of the following fields:
- Gastrointestinal Pharmacology
- Pharmacology
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Question 116
Incorrect
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Which of the following is true regarding respiration?
Your Answer: The ‘pump handle’ action of the ribs increases the transverse diameter of the chest
Correct Answer: The diaphragm is responsible for abdominal breathing
Explanation:The following are the mechanisms of breathing during inspiration and expiration, whether normal or forced.Normal inspiration is an active process, with the diaphragm as the main muscle. The diaphragm descends, ribs move upward and outward, and the lungs become wider and taller.In forced inspiration, which commonly occurs during exercise, the external intercostals and accessory muscles, such as the sternocleidomastoid, anterior serrati, scalenes, alae nasi, genioglossus and arytenoid are involved. The ribs move upward and outward, and the abdominal contents move downward.Normal expiration is a passive process, while in forced expiration, the internal intercostals and abdominal muscles, such as the rectus abdominis, internal and external obliques and transversus abdominis are involved. The ribs move downward and inward, and the abdominal contents move upward.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 117
Incorrect
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A 60-year-old male presents to the genitourinary clinic with dysuria and urinary frequency complaints. He has a past medical history of benign prostate enlargement, for which he has been taking tamsulosin. There is blood, protein, leucocytes, and nitrites on a urine dipstick. Fresh blood tests were sent, and his estimated GFR is calculated to be >60 ml/minute. A urinary tract infection (UTI) diagnosis is made, and he is prescribed antibiotics. Out of the following, which antibiotic is most appropriate to be prescribed to this patient?
Your Answer: Ciprofloxacin
Correct Answer: Nitrofurantoin
Explanation:The NICE guidelines for men with lower UTIs are:1. Prescribe an antibiotic immediately, taking into account the previous urine culture and susceptibility results or avoiding antibiotics used previously that may have caused resistance 2. Obtain a midstream urine sample before starting antibiotics and send for urine culture and susceptibility – Review the choice of antibiotic when the results are available AND- change the antibiotic according to susceptibility results if the bacteria are resistant and symptoms are not improving, using a narrow-spectrum antibiotic wherever possibleThe first choice of antibiotics for men with lower UTIs is:1. Trimethoprim200 mg PO BD for seven days2. Nitrofurantoin100 mg modified-release PO BD for 3 days – if eGFR >45 ml/minuteIn men whose symptoms have not responded to a first-choice antibiotic, alternative diagnoses (such as acute pyelonephritis or acute prostatitis) should be considered. Second-choice antibiotics should be based on recent culture and susceptibility results.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 118
Incorrect
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The following statements about cross-sectional studies are true EXCEPT?
Your Answer: An example of a cross-sectional study is the UK national census
Correct Answer: They can be used to determine the relative risk of a condition
Explanation:The UK national census is an example of a cross-sectional study.Cross-sectional studies can be used to assess the prevalence of a condition, and support or refute inferences of cause and effect.Cross-sectional studies are observations of the frequency and characteristics of a disease in a given population at one particular point in time. Cross-sectional studies do not differentiate between cause and effect and also do not establish the sequence of events.Cross-sectional studies cannot be used to calculate the relative risk of a condition.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 119
Incorrect
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Flucloxacillin is used first line for all of the following infections EXCEPT for:
Your Answer:
Correct Answer: Otitis media
Explanation:Flucloxacillin is used first line for treatment of widespread impetigo infection, cellulitis, mastitis, osteomyelitis, septic arthritis, severe erysipelas, severe/spreading otitis externa and infective endocarditis caused by staphylococci. Amoxicillin is first line for acute otitis media.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 120
Incorrect
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Which of the following medications can block the effect of adrenaline?
Your Answer:
Correct Answer: Beta-blockers
Explanation:Beta-blockers may reduce the response to adrenaline in the treatment of anaphylactic reactions. Noncardioselective beta-blockers in particular can antagonize the broncho dilating and cardio stimulatory effects of adrenaline by blocking beta-2 adrenergic receptors in the smooth muscles of the bronchial tree and in the heart muscles.
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 121
Incorrect
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A 33 year old female patient presents to emergency room with some symptoms that she thinks might be due to a drug that she has recently started. She was started on hyoscine butyl bromide for symptomatic relief of irritable bowel syndrome. The least likely expected side effect of this drug in this patient is:
Your Answer:
Correct Answer: Diarrhoea
Explanation:One of the commonest antispasmodic medications that is used is hyoscine butylbromide. It is an antimuscarinic and typical side effects of this class of drugs include:- dilation of pupils with loss of accommodation (cycloplegia) -photophobia resulting in blurred vision (Blind as a bat) -dry mouth, eyes and skin (Dry as a bone), -elevated temperature (Hot as a hare)-skin flushing (Red as a beet)-confusion or agitation particularly in the elderly (Mad as a hatter)-reduced bronchial secretions-transient bradycardia followed by tachycardia, palpitation and arrhythmias-urinary retention and/or constipation
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This question is part of the following fields:
- Gastrointestinal
- Pharmacology
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Question 122
Incorrect
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A 59-year-old woman presents with a history of tiredness and weight gain and a diagnosis of hypothyroidism is suspected.Which of these changes is likely to appear first in primary hypothyroidism?
Your Answer:
Correct Answer: Increased thyroid-stimulating hormone (TSH)
Explanation:The earliest biochemical change seen in hypothyroidism is an increase in thyroid-stimulating hormone (TSH) levels.Triiodothyronine (T3) and thyroxine (T4) levels are normal in the early stages.TBG levels are generally unchanged in primary hypothyroidism.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 123
Incorrect
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A 67-year-old man with chronic breathlessness is sent for a lung function test.Which statement concerning lung function testing is true?
Your Answer:
Correct Answer: In restrictive lung disease, the FEV 1 /FVC ratio is usually >0.7
Explanation:In restrictive lung disease, the FEV1/FVC ratio is usually >0.7%.In obstructive lung disease, FEV1 is reduced to <80% of normal and FVC is usually reduced. The FEV1/FVC ratio is reduced to 80% in the presence of symptomsModerate airflow obstruction = FEV 1 of 50-79%Severe airflow obstruction = FEV 1 of 30-49%Very severe airflow obstruction = FEV1<30%.Spirometry is a poor predictor of quality of life in COPD. However, it can be used as part of the assessment of severity of COPD.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 124
Incorrect
-
A 24-year-old athlete drinks a 500 ml hypertonic sports drink before an endurance event he participates in.Which of the following effects will this cause?
Your Answer:
Correct Answer: The interstitial fluid becomes more concentrated
Explanation:Osmosis is the passive movement of water across a semipermeable membrane from a region of low solute concentration to a region of higher solute concentration.When hypertonic fluid is ingested:The plasma becomes CONCENTRATED. The cells lose water and shrinkThe intracellular fluid becomes more concentrated.Water and ions move freely from the plasma into the interstitial fluid and the interstitial fluid becomes more concentrated. The increased osmotic potential draws water out of the cells.
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 125
Incorrect
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Which of the following is NOT a typical effect of cortisol:
Your Answer:
Correct Answer: Decreased protein catabolism
Explanation:Cortisol is a steroid hormone produced in the zona fasciculata of the adrenal cortex. It is released in response to stress and low blood glucose concentrations.Cortisol acts to: raise plasma glucose by stimulating glycolysis and gluconeogenesis in the liver and inhibiting peripheral glucose uptake into storage tissues, increase protein breakdown in skeletal muscle, skin and bone to release amino acids, increase lipolysis from adipose tissues to release fatty acidsand at higher levels and mimic the actions of aldosterone on the kidney to retain Na+ and water and lose K+ ionssuppress the action of immune cells
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 126
Incorrect
-
A 40-year-old man complains of pain and redness in his lower thigh due to an insect bite. He was diagnosed with cellulitis. Select the first-line antibiotic for cellulitis.
Your Answer:
Correct Answer: Flucloxacillin
Explanation:Cellulitis is most commonly caused by bacteria from the group Aß-hemolytic streptococcus. Cellulitis can be caused by animal bites. For uncomplicated cellulitis, flucloxacillin is the first-line antibiotic. Because it is beta-lactamase stable, it is efficient against Staphylococcus aureus.
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This question is part of the following fields:
- Infections
- Microbiology
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Question 127
Incorrect
-
A 68-year-old man has a very fast heartbeat' and is out of breath. He has had a heart transplant in the past. His electrocardiogram reveals supraventricular tachycardia.Which of the following is the most appropriate adenosine dose for him to receive as a first dose?
Your Answer:
Correct Answer: Adenosine 3 mg IV
Explanation:A rapid IV bolus of adenosine is given, followed by a saline flush. The standard adult dose is 6 mg, followed by 12 mg if necessary, and then another 12 mg bolus every 1-2 minutes until an effect is seen.Patients who have had a heart transplant, on the other hand, are extremely sensitive to the effects of adenosine and should start with a lower dose of 3 mg, then 6 mg, and finally 12 mg.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 128
Incorrect
-
A CT pulmonary angiography of a patient with a massive pulmonary embolus will most likely show which of the following signs?
Your Answer:
Correct 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 129
Incorrect
-
Intrinsic factor is secreted by which of the following cell types in the stomach:
Your Answer:
Correct Answer: Parietal cells
Explanation:Intrinsic factor is essential for the absorption of the small amounts of vitamin B12 normally present in the diet from the terminal ileum. The parietal cells of the stomach produce intrinsic factor, and following a gastrectomy, the absorption of vitamin B12 will be markedly reduced, and a deficiency state will exist.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 130
Incorrect
-
Question 131
Incorrect
-
An unrelated medical condition brings a 28-year-old asthmatic man to the Emergency Department. When you look over his meds, you notice that he is taking Theophylline to help with his asthma.Which of the following medicines should you NOT prescribe?
Your Answer:
Correct Answer: Ciprofloxacin
Explanation:Ciprofloxacin is a cytochrome P450 enzyme inhibitor that raises theophylline levels in the blood. As a result, co-prescribing theophylline should be avoided.The medicines that typically impact theophylline’s half-life and plasma concentration are listed in the table below:Drugs that increase the levels of theophylline in the bloodDrugs that lower theophylline levels in the bloodCalcium channel blockers e.g. VerapamilFluconazoleCimetidineQuinolones, e.g. ciprofloxacinMethotrexateBarbituratesCarbamazepinePhenobarbitalMacrolides, e.g. erythromycinPhenytoin (and fosphenytoin)RifampicinSt. John’s wort
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This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 132
Incorrect
-
Regarding meningococcal meningitis, which of the following statements is CORRECT:
Your Answer:
Correct Answer: Infection occurs most commonly below the age of 5 years.
Explanation:About half of meningococcal disease occurs in children aged less than five years, and babies are at the highest risk because their immune systems have not yet fully developed. There is a second, smaller increase in risk for older adolescents, mainly for social and behavioural reasons. Infection is most common in winter months. Antibiotics should be given as soon as the diagnosis is suspected (ideally cultures should be performed first but this should not delay treatment), and ceftriaxone/cefuroxime is the first line antibiotic. Only healthcare workers who have been directly exposed to large particle droplets/secretions from the respiratory tract of the index case should receive prophylaxis.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 133
Incorrect
-
A 30-year-old male farmer presents to the Emergency Department due to a wound on his right forearm sustained two days ago while working on the farm. He cleaned the wound under a tap, but there was still some dirt and debris on examination. Past medical history reveals that he never received a tetanus vaccine. After cleaning the wound and prescribing antibiotics, which ONE of the following actions should be taken to manage his tetanus risk?
Your Answer:
Correct Answer: Tetanus vaccination and 500 IU tetanus immunoglobulin
Explanation:If a patient presents with one of the following types of wounds, they are at risk of contracting tetanus and should be vaccinated immediately:1) Contaminated puncture-type wounds from gardening and farming (as they may contain tetanus spores)2) Wounds containing foreign bodies3) Open (compound) fractures4) Wounds or burns with sepsis5) Animal bites and scratches (animal saliva does not contain tetanus spores unless the animal was routing in soil or lives in an agriculture setting)Extremely high-risk tetanus-prone wounds are any of the above wounds with one of the following:1) Any wound contaminated by materials containing tetanus spores, e.g., soil, manure2) Burns or wounds with extensive devitalised tissue3) Wounds or burns with surgical intervention delayed for more than six hours even if the initial injury was not heavily contaminatedThe CDC recommends that adults who have never been vaccinated for tetanus receive a quick shot of the tetanus vaccine along with a booster dose ten years later. A tetanus-prone wound in an unvaccinated individual should also receive a high dose of tetanus immunoglobulin. The injected antibodies will prevent tetanus infection as the patient does not have any pre-existing antibodies against the disease.In this case, the patient has a high risk, contaminated wound. He should receive a high dose of tetanus immunoglobulin along with the tetanus vaccine. (The preventative dose of tetanus immunoglobulin is 250 IU in most cases unless over 24 hours have passed since the injury or the wound is heavily contaminated, then 500 IU should be given.) His physician also needs to be contacted to arrange the remainder of the course as indicated in this case.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 134
Incorrect
-
Regarding gas gangrene, which of the following statements is CORRECT:
Your Answer:
Correct Answer: Infection is characterised by rapidly spreading tissue myonecrosis with crepitus.
Explanation:Gas gangrene usually occurs within 3 days of injury, and is characterised by pain, rapidly spreading oedema, myositis, necrosis, palpable crepitus and systemic toxicity. Diagnosis is clinical and laboratory confirmation should not delay urgent surgical intervention. Hyperbaric oxygen therapy can be considered in addition to surgery and antibiotic therapy, to stop toxin production and inhibit bacteria from replicating and spreading (as Clostridium spp. are obligate anaerobes).
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 135
Incorrect
-
The following structures all lie anteriorly to the oesophagus EXCEPT for the:
Your Answer:
Correct Answer: Thoracic duct
Explanation:Posterior to the oesophagus, the thoracic duct is on the right side inferiorly but crosses to the left more superiorly (at T5).
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 136
Incorrect
-
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:
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 137
Incorrect
-
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:
Correct 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 138
Incorrect
-
Angiotensin II acts to cause all but which one of the following effects:
Your Answer:
Correct Answer: Inhibit release of ADH from the posterior pituitary gland
Explanation:Angiotensin II acts to:Stimulate release of aldosterone from the zona glomerulosa of the adrenal cortex (which in turn acts to increase sodium reabsorption)Cause systemic vasoconstrictionCause vasoconstriction of the renal arterioles (predominant efferent effect thus intraglomerular pressure is stable or increased, thereby tending to maintain or even raise the GFR)Directly increase Na+reabsorption from the proximal tubule (by activating Na+/H+antiporters)Stimulate synthesis and release of ADH from the hypothalamus and posterior pituitary respectivelyStimulate the sensation of thirstPotentiate sympathetic activity (positive feedback)Inhibit renin production by granular cells (negative feedback)
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This question is part of the following fields:
- Physiology
- Renal
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Question 139
Incorrect
-
Regarding aspirin at analgesic doses, which of the following statements is CORRECT:
Your Answer:
Correct Answer: It is contraindicated in patients with severe heart failure.
Explanation:Aspirin (at analgesic doses) is contraindicated in severe heart failure. Aspirin irreversibly inhibits cyclooxygenase (COX) enzymes resulting in decreased production of prostaglandins (which can lead to irritation of the gastric mucosa). The analgesic dose is greater than the antiplatelet dose, and taken orally it has a duration of action of about 4 hours. Clinical features of salicylate toxicity in overdose include hyperventilation, tinnitus, deafness, vasodilatation, and sweating.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 140
Incorrect
-
Regarding the lumbar plexus, which of the following is a direct muscular branch?
Your Answer:
Correct Answer: Nerve to quadratus lumborum
Explanation:The lumbar plexus gives rise to several branches which supply various muscles and regions of the posterior abdominal wall and lower limb. These branches include the Iliohypogastric, ilioinguinal, genitofemoral, lateral femoral cutaneous, femoral and obturator nerves.In addition, the lumbar plexus gives off muscular branches from its roots, a branch to the lumbosacral trunk and occasionally an accessory obturator nerve.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 141
Incorrect
-
Mannitol is primarily indicated for which of the following:
Your Answer:
Correct Answer: Cerebral oedema
Explanation:Mannitol is an osmotic diuretic that can be used to treat cerebral oedema and raised intraocular pressure. Mannitol is a low molecular weight compound and is, therefore, freely filtered at the glomerulus and is not reabsorbed. It, therefore, increases the osmolality of the glomerular filtrate and tubular fluid, increasing urinary volume by an osmotic effect. It also does not cross the blood-brain-barrier (BBB).
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 142
Incorrect
-
A 59-year-old man presents with increased sweating, weight loss, and palpitations. A series of blood tests done found a very low TSH level and a diagnosis of hyperthyroidism is made.What is the commonest cause of hyperthyroidism?
Your Answer:
Correct Answer: Graves’ disease
Explanation:Hyperthyroidism results from an excess of circulating thyroid hormones. It is commoner in women, and incidence increases with age.Hyperthyroidism can be subclassified into:Primary hyperthyroidism – the thyroid gland itself is affectedSecondary hyperthyroidism – the thyroid gland is stimulated by excessive circulating thyroid-stimulating hormone (TSH).Graves’ disease is the most common cause of hyperthyroidism (estimates are that it causes between 50 and 80% of all cases).Although toxic multinodular goitre, thyroiditis,TSH-secreting pituitary adenoma and drug-induced hyperthyroidism also causes hyperthyroidism, the commonest cause is Graves’ disease.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 143
Incorrect
-
Which of the following intravenous induction drugs results in the highest drop in blood pressure:
Your Answer:
Correct Answer: Propofol
Explanation:Propofol’s most frequent side effect is hypotension, which affects 17% of paediatric patients and 26% of adults. This is attributable to systemic vasodilation as well as a decrease in preload and afterload. Propofol has a little negative inotropic impact as well. The drop in blood pressure is dosage-dependent and is more noticeable in the elderly, thus this should be expected.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 144
Incorrect
-
Which of the following is NOT a typical clinical feature of hypoglycaemia:
Your Answer:
Correct Answer: Polyuria
Explanation:Clinical features of hypoglycaemia: Autonomic symptoms: Sweating, feeling hot, anxiety/agitation, palpitations, shaking, paraesthesia, dizzinessNeuroglycopaenic symptoms: Weakness, blurred vision, difficulty speaking, poor concentration, poor coordination, drowsiness, confusion, seizures, comaOther symptoms: Nausea, fatigue, hunger
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 145
Incorrect
-
A 19-year-old woman presents with dysuria and vaginal discharge. A swab was taken for culture. Culture results showed the presence of Neisseria gonorrhoeae infection. Treatment of azithromycin and doxycycline was started.Which of the following statements is considered correct regarding Neisseria gonorrhoeae?
Your Answer:
Correct Answer: Throat swabs can be used for diagnosis
Explanation:Neisseria gonorrhoeae is a Gram-negative diplococcus that causes gonorrhoea. Gonorrhoea is an acute pyogenic infection of nonciliated columnar and transitional epithelium; infection can be established at any site where these cells are found. Gonococcal infections are primarily acquired by sexual contact and occur primarily in the urethra, endocervix, anal canal, pharynx, and conjunctiva.In men, acute urethritis, usually resulting in purulent discharge and dysuria (painful urination), is the most common manifestation. The endocervix is the most common site of infection in women. Symptoms of infection, when present, include dysuria, cervical discharge, and lower abdominal pain. Some cases in women may be asymptomatic leading to complications such as pelvic inflammatory disease. Blood-borne dissemination occurs in less than 1% of all infections, resulting in purulent arthritis and rarely septicaemia. Fever and a rash on the extremities can also be present. Other conditions associated with N. gonorrhoeae include anorectal and oropharyngeal infections. Infections in these sites are more common in men who have sex with men but can also occur in women. Pharyngitis is the chief complaint in symptomatic oropharyngeal infections, whereas discharge, rectal pain, or bloody stools may be seen in rectal gonorrhoea. Approximately 30% to 60% of women with genital gonorrhoea have concurrent rectal infection. Newborns can acquire ophthalmia neonatorum, a gonococcal eye infection, during vaginal delivery through an infected birth canal. Specimens collected for the recovery of N. gonorrhoeae may come from genital sources or from other sites, such as the rectum, pharynx, and jointfluid. According to the 2010 STD Treatment guidelines, cephalosporins (e.g., ceftriaxone, cefixime) are currently recommended treatments.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 146
Incorrect
-
All of the muscles of the tongue (other than the palatoglossus) are innervated by which of the following nerves:
Your Answer:
Correct 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 147
Incorrect
-
Regarding the UK routine childhood immunisation schedule which of the following vaccines is NOT given at 2 months:
Your Answer:
Correct Answer: Meningococcal group C
Explanation:At 2 months the following vaccines are given: Diphtheria, tetanus, pertussis, polio, Haemophilus influenzae type b (Hib) and hepatitis BRotavirus gastroenteritisMeningococcal group B
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This question is part of the following fields:
- Immunoglobulins And Vaccines
- Pharmacology
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Question 148
Incorrect
-
A 23-year-old male is referred to your haematology clinic after an acute attack of haemolytic anaemia. He was diagnosed with glucose-6-phosphate dehydrogenase deficiency ten years ago. Which ONE of the following options is FALSE with regards to this disorder?
Your Answer:
Correct Answer: Acute haemolysis can be triggered by cephalosporin antibiotics
Explanation:Glucose-6-phosphate dehydrogenase deficiency is an X-linked recessive disorder in which there is a deficiency of the enzyme G6PD. This causes instability of red blood cell membranes under oxidative stress leading to haemolysis.Triggers include: 1) Fava beans2) Sulphonamides3) Primaquine4) Anti-TB drugs5) Infections Most individuals will be asymptomatic until exposed to one of the triggers listed above. It is the commonest human enzyme defect and affects males more than females because of the X-linked inheritance pattern. The use of penicillins and cephalosporins is generally safe.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 149
Incorrect
-
A patient suffers a lower limb fracture that causes damage to the nerve that innervates peroneus longus.Peroneus longus receives its innervation from which of the following nerves? Select ONE answer only.
Your Answer:
Correct Answer: Superficial peroneal nerve
Explanation:Peroneus brevis is innervated by the superficial peroneal nerve.Peroneus longus is innervated by the superficial peroneal nerve.Peroneus tertius is innervated by the deep peroneal nerve.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 150
Incorrect
-
You are instructed by a senior to administer Mannitol to an RTA patient with increased intracranial pressure. Mannitol is a low molecular weight compound that freely filters at the glomerulus and is not reabsorbed.Out of the following, which is a contraindication to the use of mannitol?
Your Answer:
Correct Answer: Severe pulmonary oedema
Explanation:Mannitol is the most widely used osmotic diuretic that is most commonly used to reduce cerebral oedema and intracranial pressure. It is recommended to use mannitol for the reduction of CSF pressure/cerebral oedema in a dose of 0.25-2 g/kg as an intravenous infusion over 30-60 minutes. This can be repeated 1-2 times after 4-8 hours if needed.Mannitol has several contraindications and some of them are listed below:1. Anuria due to renal disease2. Acute intracranial bleeding (except during craniotomy)3. Severe cardiac failure4. Severe dehydration5. Severe pulmonary oedema or congestion6. Known hypersensitivity to mannitol
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 151
Incorrect
-
In adults, there are normally how many teeth:
Your Answer:
Correct Answer: 32
Explanation:In adults, there are 32 teeth, 16 in the upper jaw and 16 in the lower jaw. On each side in both upper and lower arches, there are two incisors, one canine, two premolars and three molar teeth.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 152
Incorrect
-
Adenosine has a half-life of approximately:
Your Answer:
Correct Answer: 8 - 10 seconds
Explanation:Adenosine stimulates A1-adenosine receptors and opens acetylcholine sensitive K+ channels, increasing K+ efflux. This hyperpolarises the cell membrane in the atrioventricular node and, by inhibiting the calcium channels, slows conduction in the AVN. As it has a very short duration of action (half-life only about 8 – 10 seconds), most side effects are short lived.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 153
Incorrect
-
A 30-year-old man suffers from an open femoral shaft fracture after being involved in a road traffic accident. As a consequence of his injury, the nerve that was damaged innervates the popliteus muscle.In which of the following nerves is the popliteus muscle innervated by?
Your Answer:
Correct Answer: Tibial nerve
Explanation:The popliteus muscle is innervated by the tibial nerve (L4, 5 and S1).
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 154
Incorrect
-
Langhans giant cells, seen in granulomatous inflammation. are:
Your Answer:
Correct Answer: Multinucleated cells formed from fusion of epithelioid cells
Explanation:A granuloma is a collection of five or more epithelioid macrophages, with or without attendant lymphocytes and fibroblasts; epithelioid macrophages are altered macrophages which have turned themselves over to becoming giant phagocytosing and killing machines, they often fuse to become multinucleate (Langhans) giant cells.
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This question is part of the following fields:
- Inflammatory Responses
- Pathology
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Question 155
Incorrect
-
Regarding the intervertebral disc, which of the following statements is CORRECT:
Your Answer:
Correct Answer: In L4 - L5 disc herniation, the L5 spinal nerve root is the most commonly affected.
Explanation:A posterolateral herniation of the disc at the L4 – L5 level would be most likely to damage the fifth lumbar nerve root, not the fourth lumbar nerve root, due to more oblique descending of the fifth lumbar nerve root within the subarachnoid space.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 156
Incorrect
-
Which of the following nerves innervates the adductor brevis?
Your Answer:
Correct Answer: Obturator nerve
Explanation:Like the majority of the thigh adductors, adductor brevis is innervated by the obturator nerve. Obturator nerve is derived from the lumbar plexus (anterior branches of spinal nerves L2-L4).
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 157
Incorrect
-
Identify the type of graph described below:This graph is a useful tool for evaluating the performance of diagnostic tests and more generally for evaluating the accuracy of a statistical model (e.g., logistic regression, linear discriminant analysis) that classifies subjects into 1 of 2 categories, diseased or non diseased. The closer the graph is to the upper left corner, which represents 100% sensitivity and 100% specificity, the more accurate the diagnostic test.
Your Answer:
Correct Answer: ROC curve
Explanation:Receiver-operating characteristic (ROC) analysis was originally developed during World War II to analyse classification accuracy in differentiating signal from noise in radar detection. Recently, the methodology has been adapted to several clinical areas heavily dependent on screening and diagnostic tests, in particular, laboratory testing, epidemiology, radiology, and bioinformatics. ROC analysis is a useful tool for evaluating the performance of diagnostic tests and more generally for evaluating the accuracy of a statistical model (e.g., logistic regression, linear discriminant analysis) that classifies subjects into 1 of 2 categories, diseased or non diseased. Its function as a simple graphical tool for displaying the accuracy of a medical diagnostic test is one of the most well-known applications of ROC curve analysis.The closer the ROC curve is to the upper left corner, which has 100% sensitivity and 100% specificity, the higher the overall accuracy of the diagnostic test.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 158
Incorrect
-
The common bile duct drains into the duodenum in which of the following regions:
Your Answer:
Correct Answer: Second part of the duodenum
Explanation:As the common bile duct descends, it passes posterior to the first part of the duodenum before joining with the pancreatic duct from the pancreas, forming the hepatopancreatic ampulla (ampulla of Vater) at the major duodenal papilla, located in the second part of the duodenum. Surrounding the ampulla is the sphincter of Oddi, a collection of smooth muscle which can open to allow bile and pancreatic fluid to empty into the duodenum.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 159
Incorrect
-
Glucagon is secreted by which of the following pancreatic cell types:
Your Answer:
Correct Answer: α cells
Explanation:Glucagon is a peptide hormone that is produced and secreted by alpha cells of the islets of Langerhans, which are located in the endocrine portion of the pancreas. The main physiological role of glucagon is to stimulate hepatic glucose output, thereby leading to increases in glycaemia. It provides the major counter-regulatory mechanism to insulin in maintaining glucose homeostasis.Hypoglycaemia is the principal stimulus for the secretion of glucagon but may also be used as an antidote in beta-blocker overdose and in anaphylaxis in patients on beta-blockers that fail to respond to adrenaline. Glucagon then causes:GlycogenolysisGluconeogenesisLipolysis in adipose tissueThe secretion of glucagon is also stimulated by:AdrenalineCholecystokininArginineAlanineAcetylcholineThe secretion of glucagon is inhibited by:InsulinSomatostatinIncreased free fatty acidsIncreased urea productionGlycolysis is the metabolic pathway that converts glucose into pyruvate. The free energy released by this process is used to form ATP and NADH. Glycolysis is inhibited by glucagon, and glycolysis and gluconeogenesis are reciprocally regulated so that when one cell pathway is activated, the other is inactive and vice versa.Glucagon has a minor effect of enhancing lipolysis in adipose tissue. Lipolysis is the breakdown of lipids and involves the hydrolysis of triglycerides into glycerol and free fatty acids. It makes fatty acids available for oxidation.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 160
Incorrect
-
The renal team is currently prescribing erythropoietin to a patient with chronic kidney disease.Which of the following statements about erythropoietin is correct?
Your Answer:
Correct Answer: It protects red blood cell progenitors from apoptosis
Explanation:Erythropoietin is a glycoprotein hormone that regulates the formation of red blood cells (red cell production). It is mostly produced by interstitial fibroblasts in the kidney, which are located near the PCT. It is also produced in the liver’s perisinusoidal cells, however this is more common during the foetal and perinatal periods.The kidneys produce and secrete erythropoietin in response to hypoxia. On red blood cells, erythropoietin has two main effects:- It encourages stem cells in the bone marrow to produce more red blood cells.- It protects red blood cell progenitors and precursors from apoptosis by targeting them in the bone marrow.As a result of the increased red cell mass, the oxygen-carrying capacity and oxygen delivery increase.
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 161
Incorrect
-
Which of the following is NOT a function of antibodies:
Your Answer:
Correct Answer: Act as antigen receptors on T lymphocytes
Explanation:Antibodies: Neutralise toxins and prevent attachment of pathogensTarget, opsonise or agglutinate (clump together) antigens for phagocytosisActivate the complement cascade (leading to lysis or opsonisation of the pathogen)Act as antigen receptors on B lymphocytesActivate antibody-dependent cell-mediated cytotoxicity by natural killer (NK) cells or T cytotoxic cellsProvide mucosal immunity (IgA-mediated)Stimulate degranulation of mast cells (IgE and IgG mediated)Provide passive immunity to the newborn (through transplacental passage of IgG and secretion of IgA in breast milk)
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 162
Incorrect
-
The results from the study investigating the accuracy of a new diagnostic test can be displayed in the following format. How is the positive predictive value calculated:Those with diseaseThose without diseaseTotalTest positiveaba+bTest negativecdc+dTotala+cb+dn=a+b+c+d
Your Answer:
Correct Answer: a/(a+b)
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 163
Incorrect
-
A 66-year-old male presents to his family physician with the complaint of increasing fatigue and lethargy, along with itching, especially after a hot bath. He also complains of increased sweating and dizziness. On examination, he has a plethoric appearance. Abdominal examination shows the presence of splenomegaly. A basic panel of blood tests is ordered in which her Hb comes out to be 17 g/dL. Which one of the following treatment options will be most suitable in this case?
Your Answer:
Correct Answer: Venesection
Explanation:The clinical and laboratory findings, in this case, support a diagnosis of polycythaemia vera. A plethoric appearance, lethargy, splenomegaly and itching are common in this disease. Patients may also have gouty arthritis, Budd-Chiari syndrome, erythromelalgia, stroke, myocardial infarction or DVT. The average age for diagnosis of Polycythaemia Vera is 65-74 years. It is a haematological malignancy in which there is overproduction of all three cell lines. Venesection is the treatment of choice as it would cause a decrease in the number of red blood cells within the body.Erythropoietin is given in patients with chronic renal failure as they lack this hormone. Administration of erythropoietin in such patients causes stimulation of the bone marrow to produce red blood cells. Desferrioxamine is a chelating agent for iron and is given to patients with iron overload due to repeated blood transfusions, e.g. in thalassemia patients.Penicillamine is a chelating agent for Copper, given as treatment in Wilson’s disease.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 164
Incorrect
-
Regarding the refractory period, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: Action potentials can occur in the relative refractory period but the amplitude of the action potential is smaller.
Explanation:Following the action potential, Na+channels remain inactive for a time in a period known as the absolute refractory period where they cannot be opened by any amount of depolarisation. Following this there is a relative refractory period where the temporary hyperpolarisation (due to delayed closure of rectifier K+channels) makes the cell more difficult to depolarise and an action potential can be generated only in response to a larger than normal stimulus. The refractory period limits the frequency at which action potentials can be generated, and ensures that, once initiated, an action potential can travel only in one direction. An action potential is an all or nothing response so the amplitude of the action potential cannot be smaller.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 165
Incorrect
-
A 58-year-old man with a long history of depression presents with a deliberate overdose of verapamil tablets, which he is prescribed for a heart condition.What is verapamil's mechanism of action?
Your Answer:
Correct Answer: L-type calcium channel blockade
Explanation:Overdosing on calcium-channel blockers should always be taken seriously and regarded as potentially fatal. Verapamil and diltiazem are the two most lethal calcium channel blockers in overdose. These work by binding the alpha-1 subunit of L-type calcium channels, preventing calcium from entering the cell. In cardiac myocytes, vascular smooth muscle cells, and islet beta-cells, these channels play an important role.The standard ABC approach should be used to resuscitate all patients as needed. If life-threatening toxicity is expected, intubation and ventilation should be considered early on. If hypotension and shock are developing, early invasive blood pressure monitoring is recommended.The primary goal of specific treatments is to support the cardiovascular system. These are some of them:1. Fluid resuscitation: Give up to 20 mL of crystalloid per kilogramme of body weight.2. Calcium supplementationThis can be a good way to raise blood pressure and heart rate temporarily.via central venous access: 10% calcium gluconate 60 mL IV (0.6-1.0 mL/kg in children) or 10% calcium chloride 20 mL IV (0.2 mL/kg in children)Boluses can be given up to three times in a row.To keep serum calcium >2.0 mEq/L, consider a calcium infusion.3. Atropine: 0.6 mg every 2 minutes up to 1.8 mg is an option, but it is often ineffective.4. HIET (high-dose insulin-euglycemic therapy):The role of HIET in the step-by-step management of cardiovascular toxicity has changed.5. Vasoactive infusions:This was once thought to be a last-ditch measure, but it is now widely recommended that it be used sooner rather than later.Insulin with a short half-life 50 mL of 50 percent glucose IV bolus plus 1 U/kg bolus (unless marked hyperglycaemia present)Short-acting insulin/dextrose infusions should be continued.Glucose should be checked every 20 minutes for the first hour, then hourly after that.Regularly check potassium levels and replace if they fall below 2.5 mmol/L.Titrate catecholamines to effect (inotropy and chronotropy); options include dopamine, adrenaline, and/or noradrenaline infusions.6. Sodium bicarbonate: Use 50-100 mEq sodium bicarbonate (0.5-1.0 mEq/kg in children) in cases where a severe metabolic acidosis develops.7. Cardiac pacing: It can be difficult to achieve electrical capture, and it may not improve overall perfusion.Bypass AV blockade with ventricular pacing, which is usually done at a rate of less than 60 beats per minute.8. Intralipid transportCalcium channel blockers are lipid-soluble agents, so they should be used in refractory cases.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 166
Incorrect
-
A tumour compresses the jugular foramen of a 50-year-old patient. Compression of several nerves in the jugular foramen will result in which of the following complications?
Your Answer:
Correct Answer: Loss of gag reflex
Explanation:The glossopharyngeal nerve, which is responsible for the afferent pathway of the gag reflex, the vagus nerve, which is responsible for the efferent pathway of the gag reflex, and the spinal accessory nerve all exit the skull through the jugular foramen. These nerves are most frequently affected if the jugular foramen is compressed. As a result, the patient’s gag reflex is impaired. The vestibulocochlear nerve is primarily responsible for hearing. The trigeminal nerve provides sensation in the face. The facial nerve innervates the muscles of face expression (including those responsible for closing the eye). Tongue motions are controlled mostly by the hypoglossal nerve.
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This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
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Question 167
Incorrect
-
An elderly man with chronic heart and lung disease develops Legionnaires' disease. Which of the following clinical features is NOT typical of Legionnaires' disease:
Your Answer:
Correct Answer: Haemoptysis
Explanation:Legionella pneumophilais a Gram negative bacterium that is found in natural water supplies and in the soil, transmitted predominantly via inhalation of aerosols generated from contaminated water (direct person-to-person spread of infected patients does not occur). It is the cause of Legionnaires’ disease. Outbreaks of Legionnaires’ disease have been linked to poorly maintained air conditioning systems, whirlpool spas and hot tubs.The clinical features of the pneumonic form of Legionnaires’ disease include:Mild flu-like prodrome for 1-3 daysCough (usually non-productive and occurs in approximately 90%)Pleuritic chest painHaemoptysisHeadacheNausea, vomiting and diarrhoeaAnorexiaLegionella pneumophilainfections can be successfully treated with macrolide antibiotics, such as erythromycin, or quinolones, such as ciprofloxacin. Tetracyclines, such as doxycycline, can also be used.The syndrome of inappropriate antidiuretic hormone secretion (SIADH) can occur with Legionnaires’ disease and will result in hyponatraemia as is seen in this case.Legionella pneumophilainfections are resistant to amoxicillin but can be successfully treated with macrolide antibiotics, such as erythromycin, or quinolones, such as ciprofloxacin. Tetracyclines, such as doxycycline, can also be used. The majority of cases of Legionnaires’ disease are caused by Legionella pneumophila, however many other species of Legionella have been identified.Legionella longbeachae is another less commonly encountered species that has also been implicated in outbreaks. It is predominantly found in soil and potting compost, and has caused outbreaks of Pontiac fever, the non-respiratory and less severe variant of Legionnaires’ disease.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 168
Incorrect
-
An increased anion gap metabolic acidosis is typically caused by which of the following?
Your Answer:
Correct Answer: Propylene glycol overdose
Explanation:Causes of a raised anion gap acidosis can be remember using the mnemonic MUDPILES:-Methanol-Uraemia (in renal failure)-Diabetic ketoacidosis-Propylene glycol overdose-Infection/Iron overdose/Isoniazid/Inborn errors of metabolism-Lactic acidosis-Ethylene glycol overdose-Salicylate overdose
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This question is part of the following fields:
- Physiology
- Renal
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Question 169
Incorrect
-
A 30-year old male is brought to the emergency room after a terrible fall during a photoshoot. The patient reported falling on his right forearm. There is evident swelling and tenderness on the affected area, with notable weakness of the flexor pollicis longus muscle. Radiographic imaging showed a fracture on the midshaft of the right radius.Which of the following nerves is most likely injured in the case above?
Your Answer:
Correct Answer: The anterior interosseous nerve
Explanation:Flexor pollicis longus receives nervous supply from the anterior interosseous branch of median nerve, derived from spinal roots C7 and C8.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 170
Incorrect
-
Which of the following infections is vancomycin most likely prescribed for?
Your Answer:
Correct Answer: Clostridium difficile colitis
Explanation:125 mg PO q6hr for 10 days is indicated for treatment of Clostridium difficile (C. difficile)-associated diarrhoea
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 171
Incorrect
-
Which of the following muscles acts as an extensor of the shoulder joint?
Your Answer:
Correct Answer: Teres major
Explanation:The glenohumeral joint possesses the capability of allowing an extreme range of motion in multiple planes.Flexion – Defined as bringing the upper limb anterior in the sagittal plane. The usual range of motion is 180 degrees. The main flexors of the shoulder are the anterior deltoid, coracobrachialis, and pectoralis major. Biceps brachii also weakly assists in this action.Extension—Defined as bringing the upper limb posterior in a sagittal plane. The normal range of motion is 45 to 60 degrees. The main extensors of the shoulder are the posterior deltoid, latissimus dorsi, and teres major.Internal rotation—Defined as rotation toward the midline along a vertical axis. The normal range of motion is 70 to 90 degrees. The internal rotation muscles are the subscapularis, pectoralis major, latissimus dorsi, teres major, and the anterior aspect of the deltoid.External rotation – Defined as rotation away from the midline along a vertical axis. The normal range of motion is 90 degrees. Primarily infraspinatus and teres minor are responsible for the motion.Adduction – Defined as bringing the upper limb towards the midline in the coronal plane. Pectoralis major, latissimus dorsi, and teres major are the muscles primarily responsible for shoulder adduction.Abduction – Defined as bringing the upper limb away from the midline in the coronal plane. The normal range of motion is 150 degrees. Due to the ability to differentiate several pathologies by the range of motion of the glenohumeral joint in this plane of motion, it is essential to understand how different muscles contribute to this action.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 172
Incorrect
-
A 18-year-old man returns from a trip to Ibiza with a severely painful left eye. He has copious mucopurulent discharge, is febrile and has left-sided tender preauricular lymphadenopathy. He attends the local eye casualty and is diagnosed with hyperacute conjunctivitis.What is the SINGLE most likely causatiave organism?
Your Answer:
Correct Answer: Neisseria gonorrhoeae
Explanation:Hyperacute bacterial conjunctivitis is a severe, sight-threatening ocular infection that warrants immediate ophthalmic work-up and management. The infection has an abrupt onset and is characterized by a copious yellow-green purulent discharge that reaccumulates after being wiped away. Typically caused by infection with Neisseria gonorrhoeae.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 173
Incorrect
-
You're evaluating a male patient who's having a lung function test done. In calculating the patient’s functional residual capacity, what parameters should you add to derive the functional residual capacity volume?
Your Answer:
Correct Answer: Expiratory reserve volume + residual volume
Explanation:The volume of air that remains in the lungs after a single breath is known as functional residual capacity (FRC). It is calculated by combining the expiratory reserve volume and residual volume.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 174
Incorrect
-
In the United Kingdom, which of the following is the most often used intravenous aesthetic:
Your Answer:
Correct 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 175
Incorrect
-
Which one these is an example of a cause of an exudate?
Your Answer:
Correct Answer: Subphrenic abscess
Explanation:An exudate is an inflammatory fluid emanating from the intravascular space due to changes in the permeability of the surrounding microcirculation.Some common causes of exudates are: pneumonia, empyema, lung cancer, breast cancer, cancer of the pleura, SLE, rheumatoid arthritis, pericarditis, subphrenic abscess, chylothorax.Myxoedema, nephrotic syndrome, congestive cardiac failure, and liver cirrhosis all cause TRANSUDATE.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 176
Incorrect
-
A patient presents with a lump for a dermatological examination. There is a circumscribed skin elevation measuring 0.3 cm in diameter seen on examination.Which one of these best describes the lump you have found on examination?
Your Answer:
Correct Answer: Papule
Explanation:A papule is a solid, well circumscribed, skin elevation measuring less than 0.5 cm in diameter. A nodule is a solid, well circumscribed, raised area that lies in or under the skin and measures greater than 0.5 cm in diameter. They are usually painless. A bulla is a visible collection of clear fluid measuring greater 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 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 177
Incorrect
-
In which part of the gastrointestinal tract is Meckel's diverticulum commonly located?
Your Answer:
Correct 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 178
Incorrect
-
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:
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 179
Incorrect
-
A 45-year old man presented to the emergency room with complains of chest pain and breathlessness. Upon history taking and examination, it was discovered that he had a right-sided spontaneous pneumothorax and had a failed attempt at pleural aspiration. The pneumothorax is still considerable in size, but he remains breathless. A Seldinger chest drain was inserted but it started to drain frank blood shortly after. Which of the following complications is most likely to have occurred?
Your Answer:
Correct Answer: Intercostal artery laceration
Explanation:Injury to the intercostal artery (ICA) is an infrequent but potentially life-threatening complication of all pleural interventions. Traditional anatomy teaching describes the ICA as lying in the intercostal groove, protected by the flange of the rib. This is the rationale behind the recommendation to insert needles just above the superior border of the rib. Current recommendations for chest drain insertion suggest that drains should be inserted in the ‘safe triangle’ in order to avoid the heart and the mediastinum and be above the level of the diaphragm. The safe triangle is formed anteriorly by the lateral border of the pectoralis major, laterally by the lateral border of the latissimus dorsi, inferiorly by the line of the fifth intercostal space and superiorly by the base of the axilla. Imaging guidance also aids in the safety of the procedure.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 180
Incorrect
-
A young female was diagnosed with a urinary tract infection and was sent home with medications. However, after 48 hours of discharge, she returned to the hospital because there had been no relief from her symptoms. She is pregnant in her second trimester. The urine sensitivity test report is still unavailable. Fresh blood tests were sent, and her estimated GFR is calculated to be >60 ml/minute. She was prescribed nitrofurantoin 100 mg modified-release orally twice a day for two days.Out of the following, which antibiotic is most appropriate to be prescribed to this patient?
Your Answer:
Correct Answer: Cefalexin
Explanation:The NICE guidelines for pregnant women with lower UTIs are:1. Prescribe an antibiotic immediately, taking into account the previous urine culture and susceptibility results or avoiding past antibiotics that may have caused resistance2. Obtain a midstream urine sample before starting antibiotics and send for urine culture and susceptibility – Review the choice of antibiotic when the results are available – change the antibiotic according to susceptibility results if the bacteria are resistant, using a narrow-spectrum antibiotic wherever possibleThe first choice of antibiotics for pregnant women aged 12 years and over is:1. Nitrofurantoin100 mg modified-release PO BD for 3 days – if eGFR >45 ml/minuteThe second-choice (no improvement in lower UTI symptoms on first-choice for at least 48 hours, or when first-choice is not suitable) are:1. Amoxicillin 500 mg PO TDS for seven days (ONLY if culture results available and susceptible)2. Cefalexin500 mg BD for seven daysAlternative second-choices – consult local microbiologist, choose antibiotics based on culture and sensitivity results
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 181
Incorrect
-
Monoamine oxidase is primarily involved in the degradation of which of the following:
Your Answer:
Correct Answer: Noradrenaline
Explanation:Catecholamines are broken down extracellularly and in the liver by catechol-O-methyltransferase (COMT) and intracellularly by monoamine oxidase (MAO).
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 182
Incorrect
-
An analytical cohort study is done to compare the relationship between omega 3 intake and occurrence of myocardial infarction (MI) among males aged over 65 years. The following are the data from the study:No. of subjects taking placebo: 100 menNo. of subjects taking placebo who suffered an MI: 15 menNo. of subjects taking omega 3: 100 menNo. of subjects taking omega 3 who suffered an MI: 5 menCompute for the relative risk of the study.
Your Answer:
Correct Answer: 0.33
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 = (5/100) / (15/100)RR = 0.33
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This question is part of the following fields:
- Evidence Based Medicine
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Question 183
Incorrect
-
Regarding likelihood ratios, which of the following statements is INCORRECT:
Your Answer:
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 184
Incorrect
-
After an accidental fall, a 75-year-old patient complains of neck pain and weakness in his upper limbs. Select the condition that most likely caused the neck pain and weakness of the upper limbs of the patient.
Your Answer:
Correct Answer: Central cord syndrome
Explanation:The cervical spinal cord is the section of the spinal cord that goes through the bones of the neck. It is injured incompletely in the central cord syndrome (CCS). This will result in arm weakness more than leg weakness.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 185
Incorrect
-
A 29-year-old woman with anaphylactic reaction to peanuts, had to use her EpiPen on the way to hospital. What percentage of patients with anaphylactic reaction suffer a biphasic response?.
Your Answer:
Correct Answer: 20%
Explanation:About 20% of patients that suffer an anaphylactic reaction suffer a biphasic response 4-6 hours after the initial response (sometimes up to 72 hours after).
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 186
Incorrect
-
A 17-year-old patient with a headache, fever, and a non-blanching rash is brought to the emergency room. Meningococcal infection is confirmed by a lumbar puncture. Neisseria meningitidis uses one of the following immune evasion mechanisms:
Your Answer:
Correct Answer: Secretes IgA protease
Explanation:Meningococci have 3 important virulence factors, as follows:Polysaccharide capsule – Individuals with immunity against meningococcal infections have bactericidal antibodies against cell wall antigens and capsular polysaccharides; a deficiency of circulating anti meningococcal antibodies is associated with the disease.Lipo-oligosaccharide endotoxin (LOS)Immunoglobulin A1 (IgA1)
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This question is part of the following fields:
- Microbiology
- Principles
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Question 187
Incorrect
-
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:
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 188
Incorrect
-
Haemophilia B results from a deficiency in:
Your Answer:
Correct Answer: Factor IX
Explanation:Haemophilia B is a bleeding disorder caused by a deficiency of clotting factor IX. It is the second commonest form of haemophilia, and is rarer than haemophilia A. Haemophilia B tends to be similar to haemophilia A but less severe. The two disorders can only be distinguished by specific coagulation factor assays.The incidence is one-fifth of that of haemophilia A. Laboratory findings demonstrate prolonged APTT, normal PT and low factor IX.Haemophilia B inherited in an X-linked recessive fashion, affecting males born to carrier mothers.There is also a variation called Leyden, in which factor IX levels are below 1% until puberty, when they rise, potentially reaching as high as 40-60% of normal. This is thought to be due to the effects of testosterone at puberty.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 189
Incorrect
-
What is the primary route of transmission of Neisseria Gonorrhoeae?
Your Answer:
Correct Answer: Sexually transmitted
Explanation:Neisseria gonorrhoeae is primarily spread by sexual contact or through transmission during childbirth. It causes gonorrhoea which is a purulent infection of the mucous membrane surfaces.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 190
Incorrect
-
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 risk ratio of a stroke.
Your Answer:
Correct Answer: 2.5
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 = (30/300) / (20/500)RR = 2.5Recall 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 191
Incorrect
-
When treating diabetic ketoacidosis (DKA), which of the following should be given if the systolic blood pressure is initially less than 90 mmHg:
Your Answer:
Correct Answer: 500 mL sodium chloride 0.9% intravenous infusion over 10 - 15 minutes
Explanation:If SBP is less than 90 mmHg , 500 mL sodium chloride 0.9 percent should be administered intravenously over 10–15 minutes, and repeated if SBP remains less than 90 mmHg. When SBP is greater than 90 mmHg, sodium chloride infusion must be maintained at a rate that replaces the deficit.
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This question is part of the following fields:
- Endocrine
- Pharmacology
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Question 192
Incorrect
-
A 23-year-old student presents to the emergency department with a terrible headache, photophobia, and a fever. On her lower limbs, you see a non-blanching purpuric rash. In the department, a lumbar puncture is conducted. What do you think you'll notice on Gram stain:
Your Answer:
Correct Answer: Gram negative diplococci
Explanation:Bacterial meningitis and septicaemia are most commonly caused by meningococcal bacteria. The Gram-negative diplococci Neisseria Meningitidis causes meningitis. Gram stain and culture of CSF identify the etiologic organism, N meningitidis. In bacterial meningitis, Gram stain is positive in 70-90% of untreated cases, and culture results are positive in as many as 80% of cases.
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This question is part of the following fields:
- Infections
- Microbiology
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Question 193
Incorrect
-
Diagnosis of HIV is predominantly made through which of the following:
Your Answer:
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 194
Incorrect
-
Which of the following is a common adverse effect of glucagon:
Your Answer:
Correct Answer: Nausea
Explanation:Adverse effects include:Common: NauseaUncommon: VomitingRare: Abdominal pain, hypertension, hypotension, tachycardia
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This question is part of the following fields:
- Endocrine
- Pharmacology
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Question 195
Incorrect
-
You are attending to a patient that has presented with a severe headache in the Emergency Department. The patient has signs of cerebral oedema and raised intracranial pressure. You discuss the case with the on-call neurology registrar and decide to prescribe Mannitol. The nurse assisting you asks you to reconsider this management plan as she suspects the patient has a contraindication to Mannitol.Out of the following, what is a contraindication to mannitol?
Your Answer:
Correct Answer: Severe cardiac failure
Explanation:Mannitol is the most widely used osmotic diuretic that is most commonly used to reduce cerebral oedema and intracranial pressure. It is recommended to use mannitol for the reduction of CSF pressure/cerebral oedema in a dose of 0.25-2 g/kg as an intravenous infusion over 30-60 minutes. This can be repeated 1-2 times after 4-8 hours if needed.Mannitol has several contraindications and some of them are listed below:1. Anuria due to renal disease2. Acute intracranial bleeding (except during craniotomy)3. Severe cardiac failure4. Severe dehydration5. Severe pulmonary oedema or congestion6. Known hypersensitivity to mannitol
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 196
Incorrect
-
Regarding ampicillin, which of the following statements is CORRECT:
Your Answer:
Correct Answer: Ampicillin may cause a widespread maculopapular rash in a patient with glandular fever.
Explanation:Ampicillin is a broad-spectrum antibiotic, active against certain Gram-positive and Gram-negative organisms but is inactivated by penicillinases (similar to amoxicillin in spectrum). Ampicillin is associated with high levels of resistance, therefore it is often not appropriate for blind treatment of infection. It is principally indicated for the treatment of exacerbations of chronic bronchitis and middle ear infections, both of which may be due to Streptococcus pneumoniae and H. influenzae, and for urinary tract infections. Maculopapular rashes commonly occur with ampicillin (and amoxicillin) but are not usually related to true penicillin allergy. They almost always occur in patients with glandular fever; thus broad-spectrum penicillins should not be used for blind treatment of a sore throat. The risk of rash is also increased in patients with acute or chronic lymphocytic leukaemia or in cytomegalovirus infection.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 197
Incorrect
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During swallowing, which of the following structures primarily closes the tracheal opening:
Your Answer:
Correct Answer: Epiglottis
Explanation:The vocal cords of the larynx are stronglyapproximated, and the larynx is pulled upwardand anteriorly by the neck muscles. These actions,combined with the presence of ligaments thatprevent upward movement of the epiglottis, causethe epiglottis to swing back over the openingof the larynx. All these effects acting togetherprevent the passage of food into the nose andtrachea. Most essential is the tight approximationof the vocal cords, but the epiglottis helps toprevent food from ever getting as far as the vocalcords. Destruction of the vocal cords or of themuscles that approximate them can causestrangulation.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 198
Incorrect
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Your consultant decides to use ketamine for a patient requiring procedural sedation in the Emergency Department. At what receptor does ketamine primarily act:
Your Answer:
Correct Answer: NMDA receptor
Explanation:In contrast to most other anaesthetic agents, ketamine is a NMDA (N-methyl-D-aspartate) receptor antagonist. It is a non-competitive antagonist of the calcium-ion channel in the NMDA receptor. It further inhibits the NMDA-receptor by binding to its phencyclidine binding site. Ketamine also acts at other receptors as an opioid receptor agonist (analgesic effects), as an muscarinic anticholinergic receptor antagonist (antimuscarinic effects) and by blocking fast sodium channels (local anaesthetic effect).
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 199
Incorrect
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A 57-year-old woman receives vitamin B12 injections following a gastrectomy.Which of the following cell types, if absent, is responsible for her vitamin B12 deficiency?
Your Answer:
Correct Answer: Parietal cells
Explanation:Intrinsic factor, produced by the parietal cells of the stomach, is essential for the absorption of vitamin B12 from the terminal ileum. After a gastrectomy, the absorption of vitamin B12 is markedly reduced, and a deficiency will occur.
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This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 200
Incorrect
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Regarding the foetal oxygen-haemoglobin dissociation curve, which of the following statements is CORRECT:
Your Answer:
Correct Answer: The HbF dissociation curve lies to the left of that for HbA.
Explanation:Foetal haemoglobin (HbF) has a higher affinity for oxygen than adult haemoglobin (HbA) because it’s gamma chains bind 2,3-DPG less avidly than beta chains of HbA. The HbF dissociation curve lies to the left of that for HbA. In the placenta PCO2moves from the foetal to the maternal circulation, shifting the maternal curve further right and the foetal curve further left (the double Bohr effect). The higher affinity of HbF relative to HbA helps transfer oxygen from mother to foetus. Therefore even through blood returning from the placenta to the foetus in the umbilical vein has a PO2of only about 4 kPa, its saturation is 70%. Oxygen transport in the foetus is also helped by a high Hb of about 170 – 180 g/L.
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This question is part of the following fields:
- Physiology
- Respiratory
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SESSION STATS - PERFORMANCE PER SPECIALTY
