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Question 1
Incorrect
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If the ejection fraction increases, there will be a decrease in:
Your Answer: Stroke volume
Correct Answer: End-systolic volume
Explanation:An increase in ejection fraction means that a higher fraction of the end-diastolic volume is ejected in the stroke volume (e.g. because of the administration of a positive inotropic agent). When this situation occurs, the volume remaining in the ventricle after systole, the end-systolic volume, will be reduced. Cardiac output, stroke volume, and mean arterial pressure will be increased.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 2
Incorrect
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Which of the following serology results is consistent with chronic hepatitis B infection:
Your Answer: Anti-HBs positive and anti-HBc IgG positive
Correct Answer: HBsAg positive and anti-HBc IgG positive
Explanation:Disease state vs Serology
Acute hepatitis: BHBsAg, HBeAg, anti-HBc IgM
Chronic hepatitis B (low infectivity): HBsAg (>6/12), anti-HBe, anti-HBc IgG
Chronic hepatitis B (high infectivity): HBsAg (>6/12), HBeAg, anti-HBc IgG
Cleared infection: Anti-HBs, anti-HBe, anti-HBc IgG
Vaccinated: Anti-HBs -
This question is part of the following fields:
- Microbiology
- Pathogens
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Question 3
Correct
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Vitamin D is a group of secosteroids that play a role in calcium and phosphate control. Vitamin D's hormonally active metabolite is 1,25-dihydroxycholecalciferol.
Which enzyme hydroxylates 25-hydroxycholecalciferol to form 1,25-dihydroxycholecalciferol?Your Answer: 1-alpha-hydroxylase
Explanation:The hormone-active metabolite of vitamin D is 1,25-dihydroxycholecalciferol (commonly known as calcitriol). Its activities raise calcium and phosphate levels in the bloodstream.
In the presence of UVB light, 7-dehydrocholesterol is converted to cholecalciferol in the epidermal layer of the skin, resulting in 1,25-dihydroxycholecalciferol.
Cholecalciferol is then converted to 25-hydroxycholecalciferol in the endoplasmic reticulum of liver hepatocytes by 25-hydroxylase (calcifediol).
Finally, 1-alpha-hydroxylase converts 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol in the kidney. The key regulatory point in the formation of 1,25-dihydroxycholecalciferol is 1-alpha-hydroxylase, which is induced by parathyroid hormone or hypophosphatemia.
The following are the primary effects of 1,25-dihydroxycholecalciferol:
Calcium and phosphate absorption in the small intestine is increased.
Calcium reabsorption in the kidneys is increased.
Increases phosphate reabsorption in the kidneys.
Increases the action of osteoclastic bacteria (increasing calcium and phosphate resorption from bone)
Inhibits the action of 1-alpha-hydroxylase in the kidneys (negative feedback) -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 4
Correct
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Regarding gas exchange at the alveolar-capillary membrane, which of the following statements is CORRECT:
Your Answer: Transfer of oxygen is usually perfusion-limited.
Explanation:Gas exchange between alveolar air and blood in the pulmonary capillaries takes place by diffusion across the alveolar-capillary membrane. Diffusion occurs from an area of high partial pressure to an area of low partial pressure, thus the driving force for diffusion is the alveolar-capillary partial pressure gradient. Diffusion occurs until equilibrium is reached, but random movement of particles continues to occur and this is known as dynamic equilibrium. The diffusing capacity for oxygen (DLO2) cannot be measured directly but the rate of diffusion in the lungs can be estimated by measuring the diffusing capacity of the lungs for carbon monoxide (DLCO), not by measuring total lung capacity. The rate of transfer of a gas may be diffusion or perfusion limited; carbon monoxide transfer is diffusion-limited, oxygen transfer is usually perfusion-limited.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 5
Correct
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A young patient presents with the features of an easily recognisable infectious disease.
Which of the following infectious diseases typically has an incubation period of less than 1 week? Select ONE answer only.Your Answer: Cholera
Explanation:Cholera has an incubation period of 12 hours to 6 days.
Other infectious disease that have an incubation period of less than 1 week include:
Staphylococcal enteritis (1-6 hours)
Salmonella enteritis (12-24 hours)
Botulism (18-36 hours)
Gas gangrene (6 hours to 4 days)
Scarlet fever (1-4 days)
Diphtheria (2-5 days)
Gonorrhoea (3-5 days)
Yellow fever (3-6 days)
Meningococcaemia (1-7 days)
Brucellosis has an incubation period of 7-21 days.
Measles has an incubation period of 14-18 days.
Falciparum malaria usually has an incubation period of 7-14 days. The other forms of malaria have a longer incubation period of 12-40 days.
Rubella has an incubation period of 14-21 days. -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 6
Incorrect
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A patient suffered from a chest injury while working out in the gym. As a consequence of his injury, his pectoralis minor muscle was damaged.
Which of the following statements regarding the pectoralis minor muscle is considered correct?Your Answer: It overlies pectoralis major
Correct Answer: It stabilises the scapula
Explanation:The pectoralis minor, in comparison to the pectoralis major, is much thinner and triangular in shape and resides below the major. It originates from the margins of the third to fifth ribs adjacent to the costochondral junction. The fibres consequently pass upward and laterally to insert into the medial border and superior surface of the coracoid process. It is crucial in the stabilization of the scapula by pulling it downward and anteriorly against the thoracic wall.
Arterial supply to the pectoralis minor also derives from the pectoral branch of the thoracoacromial trunk. Nerve supply of the pectoralis minor is a function of the lateral pectoral nerve and the medial pectoral nerve.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 7
Correct
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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 8
Correct
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A 49-year-old man known sickle cell disease patient received a blood transfusion and developed a mild fever and dark urine 6 days after transfusion. His investigations show raised bilirubin, raised LDH, and a positive Direct Antiglobulin Test (DAT).
Which transfusion reaction is most likely occurred?Your Answer: Delayed haemolytic reaction
Explanation:Delayed haemolytic transfusion reactions (DHTRs) commonly occurs 4-8 days after blood transfusion, but can occur up to a month after. Signs and symptoms include jaundice, fever, an inadequate rise in PCV, reticulocytosis, a positive antibody screen and a positive Direct Antiglobulin Test (Coombs test). DHTRs usually have a benign course and require no treatment but sometimes, life-threatening haemolysis with severe anaemia and renal failure can occur so haemoglobin levels and renal function should be monitored.
Acute haemolytic reaction aka immediate haemolytic transfusion reaction presents with fever, chills, pain at transfusion site, nausea, vomiting, dark urine and feeling of ‘impending doom’. Often, it occurs due to ABO incompatibility.
Febrile transfusion reaction presents with a 1 degree rise in temperature from baseline during transfusion. Patient may have chills and malaise. It is the most common transfusion reaction (1 in 8 transfusions) and is usually caused by cytokines released from leukocytes in transfused red cell or platelet components.
Transfusion-associated circulatory overload (TACO) presents as acute or worsening respiratory distress within 6 hours of transfusion of a large volume of blood. It is common in patients with diminished cardiac reserve or chronic anaemia. Elderly patients, infants and severely anaemic patients are particularly susceptible. Clinical features of TACO include: Acute respiratory distress, Tachycardia, Hypertension, Acute/worsening pulmonary oedema on chest X-ray. The BNP is usually raised to at least 1.5 times the pre-transfusion baseline.
Graft versus host disease(GVHD) is an immune mediated condition that arises from a complex interaction between donor and recipients adaptive immunity. It presents as dermatitis, hepatitis and enteritis developing within 100 days after stem cell or bone marrow transplant.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 9
Correct
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In adult basic life support, chest compressions should be performed at which of the following rates:
Your Answer: 100 - 120 per minute
Explanation:Chest compressions should be performed at a rate of 100 – 120 per minute.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 10
Correct
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Contraction of the diaphragm results in which of the following effects:
Your Answer: Increased vertical dimension of the thorax
Explanation:Contraction of the diaphragm (as in inspiration) results in flattening (depression) of the diaphragm with an increase in vertical dimension of the thorax. This results in decreased intrathoracic pressure and increased intra-abdominal pressure.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 11
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 12
Correct
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A 71-year-old woman is treated with co-amoxiclav for a chest infection but she returns 1 week later. Her chest infection has resolved but she developed a profuse, offensive smelling diarrhoea and abdominal cramps. You suspect Clostridium difficile associated diarrhoea (CDAD).
ONE of these statements is true concerning this diagnosis.Your Answer: The gold standard for the diagnosis of Clostridium difficile colitis is cytotoxin assay
Explanation:Clostridium difficile, a Gram-positive, anaerobic, spore forming bacteria is present in the gut of approximately 3% of healthy adults (2012 UK HPA estimates). Following use of broad spectrum antibiotics, which alter normal gut flora, Clostridium difficile associated diarrhoea (CDAD) occurs.
Alcohol hand gel is not effective against Clostridium Difficile spores. Hand washing with soap and water is very essential for healthcare workers who come in contact with it.
Currently, the gold standard for the diagnosis of Clostridium difficile colitis is cytotoxin assay. Stool culture to detect Clostridium difficile is not specific for pathogenic strains, is expensive and therefore not specific for a diagnosis of CDAD
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 13
Correct
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Which statement regarding skeletal muscle is true?
Your Answer: Myosin is the major constituent of the thick filament
Explanation:Myosin is the major constituent of the thick filament.
Actin is the major constituent of the THIN filament.
Thin filaments consist of actin, tropomyosin and troponin in the ratio 7:1:1.
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 14
Correct
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A 43 year old lady who has a previous medical history of hyperthyroidism presents to the emergency room with sweating, palpitations and agitation. On examination, she is tachycardic, hypertensive and hyperpyrexic. She recently had a stomach bug and has not been able to take her medication regularly. The best medication to immediately treat her symptoms is which of the following?
Your Answer: Propranolol
Explanation:There is a high suspicion of a thyroid crisis in this patient and emergent treatment should be initiated even before the results of TFT’s have returned. Antiadrenergic drugs like IV propranolol should be administered immediately to minimise sympathomimetic symptoms. Antithyroid medications like propylthiouracil or carbimazole should be administered to block further synthesis of thyroid hormones. After thionamide therapy has been started to prevent stimulation of new hormone synthesis, there should then be delayed administration of oral iodine solution. Hydrocortisone administration is also recommended as it treats possible relative adrenal insufficiency while also decreases peripheral conversion of T4 to T3.
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This question is part of the following fields:
- Endocrine
- Pharmacology
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Question 15
Correct
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Antidiuretic hormone (ADH) has which of the following effects:
Your Answer: Increases urine osmolality
Explanation:ADH binds V2 receptors on renal principal cells in the late distal tubule and collecting ducts, raising cAMP levels and causing intracellular vesicles to fuse with the apical membrane. In their membrane these vesicles have water channels called aquaporins, which increase the water permeability allowing greater water reabsorption and concentration of urine. ADH also binds to V1 receptor receptors on vascular smooth muscle, causing vasoconstriction and enhancing the effect of aldosterone on sodium reabsorption in the distal tubule. ADH release is stimulated primarily by raised plasma osmolality detected by osmoreceptors in the anterior hypothalamus. Other factors that increase ADH release include: extracellular fluid volume depletion, angiotensin II, nausea, pain, stress, exercise, emotion, hypoglycaemia. ADH release is inhibited by low plasma osmolality, alcohol, caffeine, glucocorticoids and atrial natriuretic peptide (ANP). ADH deficiency (or an inadequate response to ADH) results in diabetes insipidus. Excess levels of ADH results in syndrome of inappropriate ADH secretion (SIADH).
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 16
Incorrect
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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: The median nerve
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 17
Correct
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Approximately what percentage of filtered bicarbonate is reabsorbed in the proximal tubule:
Your Answer: 80%
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 18
Correct
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A 50-year-old man has recently been on antibiotics for a chest infection. He suffers from COPD and is currently on Seretide inhalers, salbutamol, and Phyllocontin continus. Since commencing the antibiotics, he has developed nausea, vomiting and abdominal pain.
Which of the following antibiotics has he MOST LIKELY been on for his chest infection?Your Answer: Erythromycin
Explanation:Phyllocontin continues contains aminophylline, a bronchodilator used in the management of asthma and COPD.
The index patient is exhibiting symptoms of theophylline toxicity. This may have been triggered by the antibiotic he took. Macrolide antibiotics, like erythromycin and quinolone antibiotics, like ciprofloxacin and levofloxacin, increases the plasma concentration of theophyllines and can lead to toxicity.
Factors that enhance theophylline clearance include cigarette smoking, carbamazepine, phenobarbital, phenytoin, primidone, and rifampin.
Medications that inhibit clearance include ethanol, ciprofloxacin, erythromycin, verapamil, propranolol, ticlopidine, tacrine, allopurinol, and cimetidine. -
This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 19
Correct
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Injury to which nerve can lead to weakness or paralysis of the brachialis muscle?
Your Answer: The musculocutaneous nerve
Explanation:The brachialis muscle is a prime flexor of the forearm at the elbow joint. It is fusiform in shape and located in the anterior (flexor) compartment of the arm, deep to the biceps brachii. The brachialis is a broad muscle, with its broadest part located in the middle rather than at either of its extremities. It is sometimes divided into two parts, and may fuse with the fibres of the biceps brachii, coracobrachialis, or pronator teres muscles. It also functions to form part of the floor of the cubital fossa.
The brachialis is primarily supplied by the musculocutaneous nerve (C5, C6). In addition, a small lateral portion of the muscle is innervated by the radial nerve (C7).
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 20
Correct
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A 52-year old male comes to the out-patient department for a groin mass that protrudes when standing. The patient notes that it is reducible when lying down. On physical examination, there is presence of a cough impulse. The initial assessment is hernia. Further investigation reveals that the mass lies lateral to the epigastric vessels.
Among the types of hernia, which is the most likely diagnosis of the case above?Your Answer: Indirect inguinal hernia
Explanation:Inguinal hernias can present with an array of different symptoms. Most patients present with a bulge in the groin area, or pain in the groin. Some will describe the pain or bulge that gets worse with physical activity or coughing. Symptoms may include a burning or pinching sensation in the groin. These sensations can radiate into the scrotum or down the leg. It is important to perform a thorough physical and history to rule out other causes of groin pain. At times an inguinal hernia can present with severe pain or obstructive symptoms caused by incarceration or strangulation of the hernia sac contents. A proper physical exam is essential in the diagnosis of an inguinal hernia. Physical examination is the best way to diagnose a hernia. The exam is best performed with the patient standing. Visual inspection of the inguinal area is conducted first to rule out obvious bulges or asymmetry in groin or scrotum. Next, the examiner palpates over the groin and scrotum to detect the presence of a hernia. The palpation of the inguinal canal is completed last. The examiner palpates through the scrotum and towards the external inguinal ring. The patient is then instructed to cough or perform a Valsalva manoeuvre. If a hernia is present, the examiner will be able to palpate a bulge that moves in and out as the patient increases intra abdominal pressure through coughing or Valsalva.
Groin hernias are categorized into 2 main categories: inguinal and femoral.
Inguinal hernias are further subdivided into direct and indirect. An indirect hernia occurs when abdominal contents protrude through the internal inguinal ring and into the inguinal canal. This occurs lateral to the inferior epigastric vessels. The hernia contents may extend into the scrotum, and can be reduced superiorly then superolaterally. A direct inguinal hernia is protrusion of abdominal contents through the transversalis fascia within Hesselbach’s triangle. The borders of Hesselbach’s triangle are the inferior epigastric vessels superolaterally, the rectus sheath medially, and inguinal ligament inferiorly.
A femoral hernia is a protrusion into the femoral ring. The borders of the femoral ring are the femoral vein laterally, Cooper’s ligament posteriorly, the iliopubic tract/inguinal ligament anteriorly and lacunar ligament medially.
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This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 21
Incorrect
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A 58-year-old patient presents with sputum production and worsening exertional breathlessness. A spirometry is done and his results leads to a diagnosis of obstructive lung disease with mild airflow obstruction.
What FEV1 value would correspond with mild airflow obstruction according to the NICE guidelines?
Your Answer: FEV 1 50-79%
Correct Answer: FEV 1 >80%
Explanation:Airflow obstruction according to the latest NICE guidelines, is defined as:
Mild airflow obstruction = an FEV 1 of >80% in the presence of symptoms
Moderate airflow obstruction = FEV 1 of 50-79%
Severe airflow obstruction = FEV 1 of 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 22
Incorrect
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A patient with a wound infection on his right leg has reddening and oedema of the surrounding muscles. His condition has worsened considerably over the past few hours with the area now appearing blackened. There is also palpable crepitus under the skin. You suspect gas gangrene.
Which statement about Clostridium perfringens is true?Your Answer: The clinical features of gas gangrene typically appear 7 days after injury
Correct Answer: Gas gangrene is caused by the release of an alpha-toxin
Explanation:Clostridium perfringens, a Gram-positive, anaerobic, spore forming rod-shaped, pathogenic bacterium is the most commonly associated with gas gangrene (85-90% of cases), although other species can also be implicated.
Clostridium perfringens is capsulate and produces a range of toxins. Alpha-toxin is the most important and is the cause of gas gangrene.
Gas gangrene develops when a devitalized wound becomes infected with Clostridium perfringens spores from the environment. The spores germinate and multiplies in the ischaemic conditions, releasing toxins, which further damage tissues.
Usually, the clinical features of gas gangrene appear within 24 hours of injury.
Clostridium perfringens spores are not destroyed by cooking. During slow cooling and unrefrigerated storage, they germinate to form vegetative cells.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 23
Incorrect
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An 18-year-old student presents with a 1-week history of sore throat, low grade fever, and malaise. Upon history taking, she noted that she had a fine rash over her body a week ago that quickly fades. Further examination and observation was done and the presence of mild splenomegaly was noted. Her test shows positive for heterophile antibody test, suspecting a diagnosis of infectious mononucleosis.
Which of the following characteristics is mostly associated with the diagnosis of infectious mononucleosis?Your Answer: Strawberry tongue
Correct Answer: Atypical lymphocytes
Explanation:Epstein-Barr virus causes infectious mononucleosis which is a clinical entity characterized by sore throat, cervical lymph node enlargement, fatigue and fever.
It is accompanied by atypical large peripheral blood lymphocytes. These atypical lymphocytes, also known as Downey cells, are actually activated CD8 T lymphocytes, most of which are responding to EBV-infected cells.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 24
Incorrect
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A diagnosis of acute osteomyelitis was made on a patient with a known history of sickle cell disease. He has no joint prosthesis on in-dwelling metal work and no known drug allergies.
Which of the following is most likely the causative agent of the case presented above?Your Answer: Staphylococcus aureus
Correct Answer: Salmonella spp .
Explanation:Patients with sickle cell disease are prone to infection of the bone and bone marrow in areas of infarction and necrosis. Although Staphylococcus aureus is the most common cause of osteomyelitis in the general population, studies have shown that in patients with sickle cell disease, the relative incidence of Salmonella osteomyelitis is twice that of staphylococcal infection.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 25
Correct
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Regarding airway resistance, which of the following statements is CORRECT:
Your Answer: Airway resistance is predominantly determined by the radius of the airway as described by Poiseuille's law.
Explanation:Flow through airways is described by Darcy’s law which states that flow is directly proportional to the mouth-alveolar pressure gradient and inversely proportional to airway resistance. Airway resistance is primarily determined by the airway radius according to Poiseuille’s law, and whether the flow is laminar or turbulent. Parasympathetic stimulation causes bronchoconstriction and sympathetic stimulation causes bronchodilation, but mediated by beta2-adrenoceptors. Muscarinic antagonists e.g. ipratropium bromide cause bronchodilation.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 26
Correct
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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: 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 27
Incorrect
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Discontinuous capillaries are typically found where in the body:
Your Answer: Renal glomeruli
Correct Answer: Reticuloendothelial system
Explanation:Discontinuous capillaries, found in the reticuloendothelial system (bone marrow, liver and spleen), have large gaps between endothelial cells and are permeable to red blood cells.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 28
Correct
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Which of the following drug classes may cause bronchoconstriction:
Your Answer: Beta-blockers
Explanation:Beta-blockers, including those considered to be cardioselective, should usually be avoided in patients with a history of asthma, bronchospasm or a history of obstructive airways disease. However, when there is no alternative, a cardioselective beta-blocker can be given to these patients with caution and under specialist supervision. In such cases the risk of inducing bronchospasm should be appreciated and appropriate precautions taken.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 29
Correct
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What is the recommended dosing regime for amiodarone in the treatment of a stable regular broad-complex tachycardia:
Your Answer: 300 mg IV over 10 - 60 minutes, followed by an IV infusion of 900 mg over the next 24 hours
Explanation:A ventricular tachycardia (or broad-complex tachycardia of uncertain origin) should be treated with amiodarone 300 mg IV over 10 – 60 min, followed by an infusion of 900 mg over the next 24 hours.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 30
Correct
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You've been summoned to your Emergency Department resuscitation area to see a patient. You consider giving him an atropine shot because he is severely bradycardic.
Which of the following statements about the use of atropine is correct?Your Answer: It blocks the effects of the vagus nerve on both the SA and AV nodes
Explanation:At muscarinic receptors, atropine blocks the action of the parasympathetic neurotransmitter acetylcholine. As a result, it inhibits the vagus nerve’s effects on both the SA and AV nodes, increasing sinus automaticity and facilitating AV node conduction.
At muscarinic receptors, atropine blocks the action of the parasympathetic neurotransmitter acetylcholine. As a result, it inhibits the vagus nerve’s effects on both the SA and AV nodes, increasing sinus automaticity and facilitating AV node conduction.
The most common cause of asystole during cardiac arrest is primary myocardial pathology, not excessive vagal tone, and there is no evidence that atropine is helpful in the treatment of asystole or PEA. As a result, it is no longer included in the ALS algorithm’s non-shockable section. Atropine is most commonly used in the peri-arrest period. It is used to treat bradycardia (sinus, atrial, or nodal) or AV block when the patient’s haemodynamic condition is compromised by the bradycardia.
If any of the following adverse features are present, the ALS bradycardia algorithm recommends a dose of 500 mcg IV:
Shock
Syncope
Myocardial ischaemia
Heart failureAtropine is also used for the following purposes:
Topically as a cycloplegic and mydriatic to the eyes
To cut down on secretions (e.g. in anaesthesia)
Organophosphate poisoning is treated with
Atropine’s side effects are dose-dependent and include:
Mouth is parched
Vomiting and nausea
Vision is hazy
Retention of urine
Tachyarrhythmias
It can also cause severe confusion and hallucinations in patients, especially the elderly. -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 31
Correct
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A 17-year-old male patient diagnosed with cystic fibrosis is experiencing shortness of breath, coughing, and flu-like symptoms. His X-ray results shows atelectasis, or collapsed lung, specifically in his lower right lung. All of the following statements are true regarding collapsed lungs, except for which one.
Your Answer: Atelectasis is an example of a perfusion defect
Explanation:Atelectasis is a complete or partial collapse of the lung. It occurs when the alveoli deflate or are filled with alveolar fluid. It is considered a ventilation defect of the alveoli due to cystic fibrosis. It is not a perfusion defect. A perfusion defect will produce pathological dead space in which the lung alveoli are ventilated adequately but are not perfused, and there is no gas exchange. While with atelectasis, the alveoli remain perfused. However, there is impaired oxygen delivery and intrapulmonary shunting of blood will be present in the collapsed area. Since there is no exchange of gas at the capillary-alveolar interface of the collapsed segments, the pulmonary capillary blood will have similar PO2 and PCO2.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 32
Correct
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A 72 year old man is brought to ED by ambulance with sudden onset chest pain, palpitations and shortness of breath. His HR is 160 bpm and BP 90/65. ECG demonstrates new-onset fast atrial fibrillation. Which of the following is the first-line treatment option in this case:
Your Answer: Synchronised DC cardioversion
Explanation:All patients with adverse features suggesting life-threatening haemodynamic instability (shock, syncope, heart failure, myocardial ischaemia) caused by new onset atrial fibrillation should undergo emergency electrical cardioversion with synchronised DC shock without delaying to achieve anticoagulation.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 33
Incorrect
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Thyroid cancer has spread to the regional lymph nodes of a patient as seen in a staging CT scan.
The lymph from the thyroid gland will drain directly to which of the following nodes?Your Answer: Supraclavicular lymph nodes
Correct Answer: Deep lateral cervical lymph nodes
Explanation:Lymphatic drainage of the thyroid gland involves the lower deep cervical, prelaryngeal, pretracheal, and paratracheal nodes. The paratracheal and lower deep cervical nodes, specifically, receive lymphatic drainage from the isthmus and the inferior lateral lobes. The superior portions of the thyroid gland drain into the superior pretracheal and cervical nodes.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 34
Correct
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A 30-year-old woman was involved in a road traffic accident and had a class I haemorrhage.
Which physiological parameter is consistent with a diagnosis of class I haemorrhage?
Your Answer: Increased pulse pressure
Explanation:There are 4 classes of haemorrhage. Classification is based on clinical signs and physiological parameters.
In CLASS I:Blood loss (ml) is < or = 750
Blood loss(% blood volume) < or = 15%
Pulse rate (bpm) is <100
Respiratory rate is 14-20
Urine output (ml/hr) is >30
Pulse pressure is normal or increased
Systolic BP is normal
CNS/mental status patient is slightly anxiousIn CLASS II:
Blood loss (ml) is 750 – 1500
Blood loss(% blood volume) is 15 – 30%
Pulse rate (bpm) is 100 – 120
Respiratory rate is 20-30
Urine output (ml/hr) is 20-30
Pulse pressure is decreased
Systolic BP is normal
CNS/mental status patient is mildly anxiousIn CLASS III:
Blood loss (ml) is 1500 – 2000
Blood loss(% blood volume) is 30- 40%
Pulse rate (bpm) is 120 – 140
Respiratory rate is 30-40
Urine output (ml/hr) is 5-15
Pulse pressure is decreased
Systolic BP is decreased
CNS/mental status patient is anxious, confusedIn CLASS IV:
Blood loss (ml) is >2000
Blood loss(% blood volume) is >40%
Pulse rate (bpm) is >140
Respiratory rate is >40
Urine output (ml/hr) is negligible
Pulse pressure is decreased
Systolic BP is decreased
CNS/mental status patient is confused, lethargic -
This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
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Question 35
Correct
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During her pregnancy, a 28-year-old lady was given an antibiotic. The neonate was prematurely born with cyanosis and ashen grey coloured skin as a result of this. Other symptoms were hypotonia, low blood pressure, and poor feeding.
From the  following antibiotics, which one is most likely to cause this side effect?Your Answer: Chloramphenicol
Explanation:Grey baby syndrome is a rare but causes significant adverse effect caused by the build-up of chloramphenicol in neonates (particularly preterm babies).
The following are the main characteristics of ‘grey baby syndrome’:
Skin that is ashy grey in colour.
Feeding problems
Vomiting
Cyanosis
Hypotension
Hypothermia
Hypotonia
Collapse of the cardiovascular system
Distension of the abdomen
trouble breathing -
This question is part of the following fields:
- Infections
- Pharmacology
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Question 36
Incorrect
-
Which of these organisms is commonly spread by droplet transmission?
Your Answer: Poliovirus
Correct Answer: Neisseria meningitidis
Explanation:Droplets are airborne particles greater than 5 µm in size. Droplet transmission occurs during talking, coughing and sneezing where respiratory droplets are generated.
Examples of organisms transmitted by the droplet route include:
Neisseria meningitidis
Respiratory syncytial virus
Parainfluenza virus
Bordetella pertussis
Influenza virusPoliovirus and Rotavirus are transmitted by the faeco-oral route
Hepatitis B is transmitted by Sexual route
Staphylococcus aureus is transmitted by direct contact
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 37
Incorrect
-
A 77 year old lady presents to ED with her left leg shortened and externally rotated following slipping and falling on a wet bathroom floor. There is an intracapsular fracture of the neck of femur seen on imaging studies. She is at risk of avascular necrosis of the head of femur.
This is caused by lack of blood supply from which of these arteries?
Your Answer: Lateral circumflex artery
Correct Answer: Medial circumflex artery
Explanation:The primary blood supply to the head of the femur is from branches of the medial femoral circumflex artery.
The superior and inferior gluteal arteries supply the hip joint but not the head of femur.
The lateral circumflex artery anastomoses with the medial femoral circumflex artery and assists in supplying the head of femur.
The obturator artery is an important source of blood supply in children up to about 8 years. It gives rise to the artery of the head of femur which runs in the ligamentum teres and is insufficient to supply the head of femur in adults.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 38
Incorrect
-
Regarding Campylobacter gastroenteritis, which of the following statements is INCORRECT:
Your Answer: Bloody diarrhoea is a typical feature.
Correct Answer: Infection usually requires antibiotic treatment.
Explanation:Campylobacter jejuni is the primary human pathogen, typically causing dysentery (bloody diarrhoea illness) following ingestion of contaminated meat, especially poultry. Infection is typically self-limiting and does not require antibiotic therapy. Campylobacter gastroenteritis is associated with the immune-mediated complications of Guillain-Barre syndrome, reactive arthritis and Reiter’s syndrome.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 39
Incorrect
-
A patient with abdominal pain, vomiting and bloody diarrhoea develops a low platelet count and deranged renal function. A diagnosis of haemolytic uraemic syndrome is made.
Which of the following organisms is a recognised cause of haemolytic uraemic syndrome? Select ONE answer only.Your Answer: Streptococcus pyogenes
Correct Answer: Escherichia coli
Explanation:E.Colistrain 0157 causes enterohaemorrhagic diarrhoea and can be followed by haemolytic uraemic syndrome (renal failure, haemolytic anaemia and thrombocytopenia).
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 40
Correct
-
Intravenous glucose solutions are typically used in the treatment of all of the following situations except:
Your 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 41
Correct
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Question 42
Incorrect
-
Which of the following body location is the appropriate site to apply pressure when performing a carotid sinus massage?
Your Answer: Thyrohyoid membrane
Correct Answer: Thyroid cartilage
Explanation:The common carotid artery runs through the neck and divides into internal and external carotid arteries on both sides near the upper thyroid cartilage. In emergency situations, carotid sinus massage is also used to diagnose or treat paroxysmal supraventricular tachycardia.
During the procedure, to maximize access to the carotid artery, the patient is put in a supine position with the neck extended (i.e. elevating the chin away from the chest). The carotid sinus is normally positioned inferior to the angle of the jaw, near the arterial impulse, at the level of the thyroid cartilage. For 5 to 10 seconds, pressure is administered to one carotid sinus.
Although pulsatile pressure applied in a vigorous circular motion may be more effective, continuous pressure is preferred since it is more reproducible. If the predicted reaction is not obtained, the operation is repeated on the opposite side after a one- to two-minute wait.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 43
Incorrect
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The cutaneous circulation is responsible for the skin's blood supply. Because the skin is not a highly metabolically active tissue with low energy requirements, its blood supply differs from that of other tissues. Instead of capillaries, some of the circulating blood volume in the skin passes through arteriovenous anastomoses (AVAs).
Which of the following statements regarding arteriovenous anastomoses is correct?
Your Answer: AVAs are short vessels with little to no smooth muscle in their walls
Correct Answer: AVAs are innervated by sympathetic fibres originating from the hypothalamus
Explanation:Short vessels called arteriovenous anastomoses (AVAs) link tiny arteries and veins. They have a large lumen diameter. The strong and muscular walls allow AVAs to completely clog the vascular lumen, preventing blood flow from artery to vein (acting like a sphincter). When the AVAs open, they create a low-resistance connection between arteries and veins, allowing blood to flow into the limbs’ superficial venous plexuses. There is no diffusion of solutes or fluid into the interstitium due to their strong muscle walls.
AVAs are densely innervated by adrenergic fibres from the hypothalamic temperature-regulation centre. High sympathetic output occurs at normal core temperatures, inducing vasoconstriction of the AVAs and blood flow through the capillary networks and deep plexuses. When the temperature rises, sympathetic output decreases, producing AVA vasodilation and blood shunting from the artery to the superficial venous plexus. Heat is lost to the environment as hot blood rushes near to the skin’s surface.
AVAs are a specialized anatomical adaptation that can only be found in large quantities in the fingers, palms, soles, lips, and pinna of the ear. -
This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
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Question 44
Incorrect
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Question 45
Incorrect
-
Regarding bias, which of the following statements is CORRECT:
Your Answer: Increasing the sample size reduces bias.
Correct Answer: Bias leads to the systematic difference between the results from a study and the true states of affair.
Explanation:Bias is the term used to describe an error at any stage of the study that was not due to chance. Bias leads to the systematic difference between the results from a study and the true states of affair. Bias may be introduced at all stages of the research process, from study design, through to analysis and publication. Bias can create a spurious association or mask a real association.Good research design can reduce the effect of bias (e.g. blinding, randomisation) but they cannot eliminate it completely. Increasing the sample size does not reduce bias.
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This question is part of the following fields:
- Evidence Based Medicine
- Study Methodology
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Question 46
Incorrect
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At rest, skeletal muscle accounts for between 15-20% of cardiac output and accounts for around 50% of body weight. This can increase to nearly 80% of cardiac output during exercise. Skeletal muscle circulation is highly controlled and has a number of specialized adaptations as a result of this high degree of disparity during exercise, in combination with the diversity in the size of skeletal muscle around the body.
What is the primary mechanism for boosting skeletal muscle blood flow during exercise?
Your Answer: Capillary angiogenesis
Correct Answer: Metabolic hyperaemia
Explanation:In skeletal muscle, blood flow is closely related to metabolic rate. Due to the contraction of precapillary sphincters, most capillaries are blocked off from the rest of the circulation at rest and are not perfused. This causes an increase in vascular tone and vessel constriction. As metabolic activity rises, this develops redundancy in the system, allowing it to cope with greater demand. During exercise, metabolic hyperaemia, which is induced by the release of K+, CO2, and adenosine, recruits capillaries. Sympathetic vasoconstriction in the active muscles is overridden by this. Simultaneously, blood flow in non-working muscles is restricted, preserving cardiac output. During exercise, muscle contractions pump blood through the venous system, raising the pressure differential between arterioles and venules and boosting blood flow via capillaries.
Capillary angiogenesis is evident when muscles are used repeatedly (e.g. endurance training). It is a long-term effect, not a quick fix for increased blood flow.
The local partial pressure of alveolar oxygen is the primary intrinsic control of pulmonary blood flow (pAO2). Low pAO2 promotes arteriole vasoconstriction and vice versa. The hypoxic pulmonary vasoconstriction (HPV) reflex allows blood flow to be diverted away from poorly ventilated alveoli and towards well-ventilated alveoli in order to maximize gaseous exchange.
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This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
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Question 47
Incorrect
-
Clostridium tetani causes which of the following infectious diseases:
Your Answer: Toxic shock syndrome
Correct Answer: Tetanus
Explanation:Clostridium tetani causes tetanus.
Scarlet fever is caused by Streptococcus pyogenes.
Toxic shock syndrome is caused by Staphylococcus aureus or Streptococcus pyogenes.
Gas gangrene is primarily caused by Clostridium perfringens.
Pseudomembranous colitis is commonly caused by Clostridium difficile. -
This question is part of the following fields:
- Microbiology
- Pathogens
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Question 48
Incorrect
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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 patient should be lying flat during the procedure
Correct 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 49
Incorrect
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A GP is considering prescribing a non-steroidal anti-inflammatory (NSAID) for pain relief for a patient with a knee injury
Which of these statements about NSAIDs is NOT true?Your Answer: Most NSAIDs act as non-selective inhibitors of the enzyme cyclo-oxygenase
Correct Answer: Side effects are less commonly seen with indomethacin than naproxen
Explanation:Most NSAIDs act as non-selective inhibitors of the enzyme cyclo-oxygenase (COX). They inhibit both COX-1 and COX-2 isoenzymes.
Only about 60% of patients will respond to any given NSAID.
It can take 21 days of treatment for a clinically appreciable reduction in inflammation to be apparent. If no improvement is seen after 21 days, the NSAID should be changed.
The use of NSAIDs in the 3rd trimester of pregnancy is associated with the following risks: delayed onset of labour, premature closure of ductus arteriosus and foetal kernicterus.
Side effects are lowest in Ibuprofen and highest in indomethacin. so side effects are more commonly seen with indomethacin than naproxen.
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This question is part of the following fields:
- Musculoskeletal Pharmacology
- Pharmacology
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Question 50
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: Conversion of fibrinogen to fibrin
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 factorAny 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) FibrinolysisFibrin (factor Ia) is a long, thin protein with branches produced at the end of the coagulation cascade when fibrinogen (factor I) is converted to fibrin, which stabilizes the blood clot.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 51
Incorrect
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Which of the following statements about propofol is TRUE:
Your Answer: If accidentally injected outside a vein it can cause tissue necrosis.
Correct Answer: Propofol has some antiemetic action.
Explanation:Propofol has some antiemetic properties. It’s for this reason that it’s used to treat postoperative nausea and vomiting. Propofol is mostly processed in the liver, with the kidneys excreting just around 1% of it unaltered. Propofol, unlike thiopental, does not produce tissue necrosis when it is extravasated. Propofol lowers intracranial pressure via lowering brain metabolic rate and cerebral blood flow. Propofol is thought to be safe for people with bronchial asthma and chronic obstructive pulmonary disease.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 52
Correct
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A 58-year-old male has cellulitis of his left leg. Because he is allergic to penicillin, you start him on erythromycin.
What is erythromycin's mechanism of action?Your Answer: Inhibition of protein synthesis
Explanation:Bacteriostatic antibiotics include erythromycin and other macrolide antibiotics. They work by attaching to the bacterial ribosome’s 50S subunit, preventing translocation and thereby protein synthesis. Macrolide antibiotics are actively concentrated inside leukocytes and delivered to the infection site as a result.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 53
Correct
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A well recognised adverse effect of metoclopramide is which of the following?
Your Answer: Acute dystonic reaction
Explanation:Side effects of metoclopramide are commonly associated with extrapyramidal effects and hyperprolactinemia. Therefore its use must be limited to short-term use. Metoclopramide can induce acute dystonic reactions which involve facial and skeletal muscle spasms and oculogyric crises. These dystonic effects are more common in the young girls and young women, and in the very old. These symptoms usually occur shortly after starting treatment with this drug and subside within 24 hours of stopping it. Abortion of dystonic attacks can be carried out by injection of an antiparkinsonian drug like procyclidine.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 54
Incorrect
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A 15-year-old male is admitted to a rehabilitation centre with a history of multiple strokes, myopathy and learning disabilities since childhood. He is under the care of a multidisciplinary team, and his genetic testing reports show the presence of a mitochondrial disorder.
Which one of the following diseases does this patient most likely have?Your Answer: Tay-Sachs disease
Correct Answer: MELAS
Explanation:Mitochondrial diseases are a group of disorders caused by dysfunctional mitochondria. Most cases are maternally inherited, as we inherit our mitochondrial DNA from our mothers only, although mutations in nuclear DNA cause some cases.
Examples of Mitochondrial Diseases include:
1. Mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS)
2. Mitochondrial epilepsy with ragged red fibres (MERRF)
3. Leber’s hereditary optic neuropathy (LHON)
4. Diabetes mellitus and deafness (DAD)
5. Neuropathy, ataxia, retinitis pigmentosa, and ptosis (NARP)
6. Leigh syndrome (subacute sclerosing encephalopathy).Red-green colour blindness and G6PD deficiency have an X-linked recessive pattern of inheritance.
Tay-Sachs Disease and spinal muscular atrophy have an autosomal recessive pattern of inheritance.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 55
Correct
-
All of the following statements are considered true regarding randomized control trials, except:
Your Answer: They can eliminate the need for further studies
Explanation:Meta-analysis is a quantitative, formal, epidemiological study design used to systematically assess previous research studies to derive conclusions about that body of research. Outcomes from a meta-analysis may include a more precise estimate of the effect of treatment or risk factor for disease, or other outcomes, than any individual study contributing to the pooled analysis. The examination of variability or heterogeneity in study results is also a critical outcome.
The benefits of meta-analysis include a consolidated and quantitative review of a large, and often complex, sometimes apparently conflicting, body of literature. The specification of the outcome and hypotheses that are tested is critical to the conduct of meta-analyses, as is a sensitive literature search.Important medical questions are typically studied more than once, often by different research teams in different locations. In many instances, the results of these multiple small studies of an issue are diverse and conflicting, which makes the clinical decision-making difficult. The need to arrive at decisions affecting clinical practise fostered the momentum toward evidence-based medicine. Evidence-based medicine may be defined as the systematic, quantitative, preferentially experimental approach to obtaining and using medical information. Therefore, meta-analysis, a statistical procedure that integrates the results of several independent studies, plays a central role in evidence-based medicine.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 56
Correct
-
Which of the following pathogens is the common cause of diarrhoea in a patient who has had a prolonged course of a broad spectrum of antibiotics?
Your Answer: Clostridium difficile
Explanation:Clostridium difficile is the most likely cause of diarrhoea after a long course of broad-spectrum antibiotic treatment.
Clostridium difficile-associated diarrhoea appeared to be linked to an increase in the usage of third-generation cephalosporins.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 57
Incorrect
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A 5-year-old girl is brought into the Paediatric ER for acute seizures. She has been convulsing for the past 18 minutes now and was already two doses of lorazepam in the ambulance. Now, you prepare a phenytoin infusion to abolish the seizures.
According to the APLS algorithm, what dose of phenytoin is advised for a convulsing child at this stage?Your Answer: 100 mg/kg over 20 minutes
Correct Answer: 20 mg/kg over 20 minutes
Explanation:Advanced paediatric life support (APLS) recommends phenytoin as the first choice for second-line anticonvulsant in a patient that continues to seize ten minutes after the second dose of the first-line anticonvulsant (benzodiazepine). (step 3 of the APLS algorithm)
The recommended dose of phenytoin infusion is up at 20 mg/kg over 20 minutes. If the patient has already taken phenytoin as maintenance therapy or is allergic to phenytoin, then a phenobarbitone infusion should be set up at 20 mg/kg over 30-60 minutes.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 58
Incorrect
-
A 40-year-old man with episodes of blood in urine and flank pain that are recurrent presents for management. He has a history of hypertension that is difficult to control and recurrent urinary tract infections. Other findings are: bilateral masses in his flanks and haematuria (3+ on dipstick).
What is the most likely diagnosis?Your Answer: Alport syndrome
Correct Answer: Polycystic kidney disease
Explanation:Autosomal dominant polycystic kidney disease (ADPKD) presents with abdominal or loin discomfort due to the increasing size of the kidneys, acute loin pain with or without haematuria, hypertension, and male infertility. It is the most common cause of serious renal disease and the most common inherited cause of renal failure in adults.
Alport syndrome has hearing loss and eye abnormalities in addition to symptoms of kidney disease.
Renal cell carcinoma presents with additional features of unexplained weight loss, loss of appetite, fever of unknown origin and anaemia.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 59
Incorrect
-
Which of the following statements about lithium treatment is FALSE:
Your Answer: Lithium may lower the seizure threshold in patients with epilepsy.
Correct Answer: Concomitant treatment with NSAIDs decreases serum-lithium concentration.
Explanation:Lithium levels are raised by NSAIDs because renal clearance is reduced. Lithium is a small ion (74 Daltons) with no protein or tissue binding and is therefore amenable to haemodialysis. Lithium is freely distributed throughout total body water with a volume of distribution between 0.6 to 0.9 L/kg, although the volume may be smaller in the elderly, who have less lean body mass and less total body water. Steady-state serum levels are typically reached within five days at the usual oral dose of 1200 to 1800 mg/day. The half-life for lithium is approximately 18 hours in adults and 36 hours in the elderly.
Lithium is excreted almost entirely by the kidneys and is handled in a manner similar to sodium. Lithium is freely filtered but over 60 percent is then reabsorbed by the proximal tubules. -
This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 60
Incorrect
-
Regarding red blood cell group antigens and antibodies, which of the following statements is CORRECT:
Your Answer: Approximately 10 red blood group antigens have been described.
Correct Answer: Anti-D antibodies are usually IgG.
Explanation:Approximately 400 red blood cell group antigens have been described. The ABO group antigens are unusual in that naturally occurring antibodies occur in the plasma of subjects who lack the corresponding antigen, even if they have not been exposed to that antigen previously. The most important of these natural antibodies are anti-A and anti-B, which are usually IgM. Anti-D antibodies don’t occur naturally, and are therefore immune antibodies that result from previous transfusions or pregnancy. Only IgG antibodies are capable of transplacental passage and the most important immune antibody is the Rh antibody, anti-D.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 61
Incorrect
-
You examine a 72-year-old man who has recently begun bumetanide treatment for worsening heart failure.
Which of these statements about bumetanide is correct?Your Answer: It is a thiazide diuretic
Correct Answer: It has better intestinal absorption than furosemide
Explanation:Bumetanide is a loop diuretic that is used to treat congestive heart failure. It is frequently used in patients who have failed to respond to high doses of furosemide.
It has a potency of about 40 times that of furosemide, with a 1 mg dose being roughly equivalent to a 40 mg dose of furosemide.
Seizures are not known to be triggered by bumetanide. In fact, it lowers the concentration of neuronal chloride, making GABA’s action more depolarizing, and it’s currently being tested as an antiepileptic in the neonatal period.It takes effect after 1 hour of oral administration, and diuresis takes 6 hours to complete.
Bumetanide absorbs much better in the intestine than furosemide. Because it has a higher bioavailability than furosemide, it is commonly used in patients with gut oedema.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 62
Incorrect
-
All of the muscles of the tongue (other than the palatoglossus) are innervated by which of the following nerves:
Your Answer: Mandibular nerve
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 63
Incorrect
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Regarding disseminated intravascular coagulation (DIC), which of the following statements is INCORRECT:
Your Answer: There is stimulation of both the coagulation cascade and of fibrinolysis.
Correct Answer: Thrombocytosis results in widespread platelet aggregation.
Explanation:DIC is characterised by a widespread inappropriate intravascular deposition of fibrin with consumption of coagulation factors and platelets. This may occur as a consequence of many disorders that release procoagulant material into the circulation or cause widespread endothelial damage or platelet aggregation. Increased activity of thrombin in the circulation overwhelms its normal rate of removal by natural anticoagulants. In addition to causing increased deposition of fibrin in the microcirculation and widespread platelet aggregation to the vessels, intravascular thrombin formation interferes with fibrin polymerisation. Intense fibrinolysis is stimulated by thrombi on vascular walls and the release of fibrin degradation products again interferes with fibrin polymerisation. The combined action of thrombin and plasmin causes depletion of fibrinogen and all coagulation factors, compounded by thrombocytopaenia caused by platelet consumption.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 64
Correct
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If the afferent arteriole's diameter is smaller than the efferent arteriole's diameter in the glomerulus:
Your Answer: The net filtration pressure will decrease
Explanation:The relative resistance of the afferent and efferent arterioles substantially influences glomerular capillary hydrostatic pressure and consequently GFR. Filtration is forced through the filtration barrier due to high pressure in the glomerular capillaries. Afferent arteriolar constriction lowers this pressure while efferent arteriolar constriction raises it.
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This question is part of the following fields:
- Physiology
- Renal
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Question 65
Incorrect
-
The movement of molecules across the cell membrane relies greatly on active transport.
Which of the following statements about active transport is correct?Your Answer: Secondary active transport derives energy from adenosine triphosphate (ATP)
Correct Answer: Active transport occurs in glucose absorption from the gut
Explanation:The movement of a material against a concentration gradient, i.e. from a low to a high concentration, is known as active transport. Primary active transport is defined as active transport that involves the use of chemical energy, such as adenosine triphosphate (ATP). Secondary active transport occurs when an electrochemical gradient is used.
The sodium-potassium pump, calcium ATPase pump, and proton pump are all key active transport systems that use ATP. An electrochemical gradient is used by the sodium-calcium co-transporter, which is an example of secondary active transport.
The sodium-dependent hexose transporter SGLUT-1 transports glucose and galactose into enterocytes. Secondary active transport is exemplified here.
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 66
Incorrect
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The patient is a 66-year-old woman who has troublesome bilateral ankle swelling. This has been happening since she began taking a new antihypertensive medication a few weeks ago.
Which of the following medications is most likely to be the cause of this adverse reaction?Your Answer: Bendroflumethiazide
Correct Answer: Amlodipine
Explanation:Amlodipine is a calcium-channel blocker that is frequently used to treat hypertension. Ankle swelling is a very common side effect of calcium-channel blockers, and it occurs quite frequently.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 67
Incorrect
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A 60-year-old man diagnosed with chronic kidney disease has an elevated creatinine level and a reduced glomerular filtration rate (GFR).
Which statement concerning glomerular filtration is true?Your Answer: The GFR declines with age after the age of 40 at a rate of approximately 5 ml/min/year
Correct Answer: Creatinine is freely filtered at the glomerulus
Explanation:Glomerular filtration is a passive process. It depends on the net hydrostatic pressure across the glomerular capillaries, the oncotic pressure, and the intrinsic permeability of the glomerulus.
The mean values for glomerular filtration rate (GFR) in young adults are 130 ml/min/1.73m2 in males and 120 ml/min/1.73m2in females.
The GFR declines with age after the age of 40 at a rate of approximately 1 ml/min/year.
The Cockcroft and Gault formula overestimates creatinine in obese patients. This is because their endogenous creatinine production is less than that predicted by overall body weight.
Creatinine is used in the estimation of GFR because it is naturally produced by muscle breakdown, not toxic, not produced by the kidney, freely filtered at the glomerulus, not reabsorbed from the nephron, and does not alter GFR.
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 68
Incorrect
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All of the following typically occurs as part of normal passive expiration except:
Your Answer: Depression of the sternal ends of the ribs
Correct 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. -
This question is part of the following fields:
- Anatomy
- Thorax
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Question 69
Incorrect
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A 70-year-old patient develops bacteraemia following peripheral cannulation.
Which of these bacteria is the most likely cause of the infection?Your Answer: Pseudomonas aeruginosa
Correct Answer: Staphylococcus epidermidis
Explanation:The commonest implicated organisms in hospital-acquired bacteraemia following cannulation are Staphylococcus aureus and Staphylococcus epidermidis.
The risk is directly proportional to the length of time in-situ. Peripheral cannula should be replaced after 48 hours. -
This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 70
Incorrect
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A 52-year-old woman visits her local pharmacy to get medication to help with mild dyspepsia symptoms. The pharmacist on duty suggests she uses an over-the-counter antacid. She purchases an antacid that contains magnesium carbonate, which relieves her symptoms, but she unfortunately also develops a side effect.
Out of the following, which side effect is she MOST likely to develop after using the antacid?Your Answer: Renal impairment
Correct Answer: Diarrhoea
Explanation:Magnesium carbonate is an over the counter antacid commonly used to relieve symptoms in ulcer dyspepsia and non-erosive gastro-oesophageal reflux.
Antacids containing magnesium also tend to work as a laxative, while the antacids with aluminium may cause constipation. There is no significant increased risk of anaphylaxis, hepatotoxicity or renal impairment.
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This question is part of the following fields:
- Gastrointestinal Pharmacology
- Pharmacology
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Question 71
Incorrect
-
Which of the following is the most common cause of megaloblastic anaemia:
Your Answer: Thalassaemia
Correct Answer: Vitamin B12 deficiency
Explanation:Megaloblastic anemia results from inhibition of DNA synthesis during red blood cell production. When DNA synthesis is impaired, the cell cycle cannot progress from the growth stage to the mitosis stage. This leads to continuing cell growth without division, which presents as macrocytosis, with an increase in mean corpuscular volume (MCV). The defect in red cell DNA synthesis is most often due to hypovitaminosis, specifically vitamin B12 deficiency or folate deficiency.
Folate is an essential vitamin found in most foods, especially liver, green vegetables and yeast. The normal daily diet contains 200 – 250 μg, of which about 50% is absorbed. Daily adult requirements are about 100 μg. Absorption of folate is principally from the duodenum and jejunum. Stores of folate are normally only adequate for 4 months and so features of deficiency may be apparent after this time. -
This question is part of the following fields:
- Haematology
- Pathology
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Question 72
Correct
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Which of the following statements accurately describes the extensor indicis muscle?
Your Answer: It lacks the juncturae tendinum
Explanation:Extensor indicis is a narrow, elongated muscle found in the posterior compartment of the forearm. It belongs to the deep extensors of the forearm, together with supinator, abductor pollicis longus, extensor pollicis longus, and extensor pollicis brevis muscles. It lacks the juncturae tendinum, which connects the extensor digitorum on the dorsal aspect of the hand.
Extensor indicis can be palpated by applying deep pressure over the lower part of the ulna while the index finger is extended. The main function of extensor indicis involves the extension of the index finger at the metacarpophalangeal and interphalangeal joints. As the index finger is one of the few fingers that have their own separate extensor muscle, it is able to extend independently from other fingers. Additionally, extensor indicis muscle produces a weak extension of the wrist.
Extensor indicis receives its nervous supply from posterior interosseous nerve, a branch of the radial nerve derived from spinal roots C7 and C8. The skin overlying the muscle is supplied by the same nerve, with fibres that stem from the spinal roots C6 and C7.
The superficial surface of the extensor indicis receives arterial blood supply from posterior interosseous branch of the ulnar artery, whereas its deep surface receives blood from perforating branches of the anterior interosseous artery.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 73
Incorrect
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The patient is a 61-year-old man with severe central chest pain. An acute myocardial infarction is revealed by his ECG. Clopidogrel is one of the medications he takes as part of his treatment.
Clopidogrel's direct mechanism of action is which of the following?Your Answer: Antagonsim of glycoprotein IIb/IIIa receptors
Correct Answer: Inhibition of platelet ADP receptors
Explanation:Clopidogrel, a thienopyridine derivative, prevents platelet aggregation and cross-linking by the protein fibrin by inhibiting the ADP receptor on platelet cell membranes (inhibits binding of ADP to its platelet receptor (P2Y12 ADP-receptor).
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 74
Correct
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Question 75
Correct
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A 25-year-old man suffers from a shoulder injury that damaged the nerve that innervates the infraspinatus muscle.
Which of the following nerves may most likely be affected?Your Answer: The suprascapular nerve
Explanation:The suprascapular nerve (C5-C6) innervates the infraspinatus. It originates at the superior trunk of the brachial plexus. It runs laterally across the lateral cervical region to supply the infraspinatus and also the supraspinatus.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 76
Correct
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Gastrin release from antral G-cells is stimulated by all but which one of the following:
Your Answer: Secretin
Explanation:Gastrin secretion is stimulated by:
The presence of small peptides and amino acids in chyme
Gastric distension
Vagal stimulation directly via acetylcholine and indirectly via gastrin-releasing peptide (GRP)
Raised gastric pH -
This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 77
Incorrect
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All of the following statements are considered true regarding nominal variables, except:
Your Answer: Hair colour is a nominal variable
Correct Answer: The central tendency of a nominal variable is given by its median
Explanation:A nominal variable is a type of variable that is used to name, label or categorize particular attributes that are being measured. It takes qualitative values representing different categories, and there is no intrinsic ordering of these categories.
A nominal variable is one of the 2 types of categorical variables and is the simplest among all the measurement variables. Some examples of nominal variables include gender, name, phone, etc.A nominal variable is qualitative, which means numbers are used here only to categorize or identify objects. They can also take quantitative values. However, these quantitative values do not have numeric properties. That is, arithmetic operations cannot be performed on them. If the variable is nominal, the mode is the only measure of central tendency to use.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 78
Incorrect
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A 40-year-old man with reduced urine output, nausea, and confusion also has a 150% rise of creatinine from baseline over the past 7 days. A diagnosis of acute kidney injury (AKI) is made after more tests are done.
His AKI stage is?Your Answer: Stage 1
Correct Answer: Stage 2
Explanation:This patient with a 150% rise of creatinine above baseline within 7 days has stage 2 Acute kidney injury (AKI).
AKI stages are as follows:
Stage 1
Creatinine rise of 26 micromole/L or more within 48 hours, or
Creatinine rise of 50-99% from baseline within 7 days (1.5-1.99 x baseline),or
Urine output <0.5 mL/kg/hour for more than 6 hours Stage 2
Creatinine rise of 100-199% from baseline within 7 days (2.0-2.99 x baseline),or
Urine output <0.5 mL/kg/hour for more than 12 hours Stage 3
Creatinine rise of 200% or more from baseline within 7 days (3.0 or more x baseline), or
Creatinine rise to 354 micromole/L or more with acute rise of 26 micromole/L or more within 48 hours or 50% or more rise within 7 days, or
Urine output <0.3 mL/kg/hour for 24 hours or anuria for 12 hours -
This question is part of the following fields:
- General Pathology
- Pathology
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Question 79
Incorrect
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Most of the lymph from vessels that drain the breast is collected in which of the following lymph nodes?
Your Answer: Parasternal nodes
Correct Answer: Axillary nodes
Explanation:Lymph is the fluid that flows through the lymphatic system.
Axillary lymph nodes are near the breasts. They are often the first location to which breast cancer spreads if it moves beyond the breast tissue. They receive approximately 75% of lymph drainage from the breast via lymphatic vessels, laterally and superiorly.
The lymph usually first drains to the anterior axillary nodes, and from here, through the central axillary, apical, and supraclavicular nodes in sequence.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 80
Incorrect
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You examine a 50-year-old female who has a swollen, painful right big toe. She has a history of gout, and this discomfort is identical to prior relapses, according to her. She is currently taking 200 mg of allopurinol per day and has been for the last year. This is her second round of acute gout within this time period. She has no prior medical history to speak of and does not take any other medications. She doesn't have any known drug allergies.
Which of the following management options is the SINGLE MOST APPROPRIATE?Your Answer: Continue with the allopurinol and commence colchicine
Correct Answer: Continue with the allopurinol and commence naproxen
Explanation:Allopurinol should not be started during an acute gout episode because it can both prolong and trigger another acute attack. Allopurinol should be continued in patients who are currently taking it, and acute attacks should be treated as usual with NSAIDs or colchicine, as needed.
Non-steroidal anti-inflammatory medications (NSAIDs), such as naproxen, are the first-line treatment for acute gout attacks. Colchicine can be used in situations where NSAIDs are contraindicated, such as in patients with hypertension or those who have had a history of peptic ulcer disease. Because there is no reason for this patient to avoid NSAIDs, naproxen would be the medicine of choice from the list above.
It would be reasonable to titrate up the allopurinol dose once the acute episode has subsided, targeting <6 mg/dl (<360 µmol/l) plasma urate levels .
Febuxostat (Uloric) is a drug that can be used instead of allopurinol to treat persistent gout. -
This question is part of the following fields:
- Musculoskeletal Pharmacology
- Pharmacology
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Question 81
Correct
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Flumazenil is a reversal agent for which of the following groups of drugs:
Your Answer: Benzodiazepines
Explanation:Flumazenil is a benzodiazepine antagonist used for the reversal of the sedative effects of benzodiazepines after anaesthesia, sedation and similar procedures.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 82
Incorrect
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Which of the following local anaesthetics has the longest duration of action:
Your Answer: Chloroprocaine
Correct Answer: Bupivacaine
Explanation:Bupivacaine has a longer duration of action than the other local anaesthetics, up to 8 hours when used for nerve blocks. It has a slow onset, taking up to 30 minutes for full effect. It is often used in lumbar epidural blockade and is particularly suitable for continuous epidural analgesia in labour, or for postoperative pain relief. It is the principal drug used for spinal anaesthesia.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 83
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:
Hypertension
Angina
Atrial fibrillation
MigraineCalcium-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:
Amlodipine
Felodipine
Nifedipine
NimodipineThe 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 84
Incorrect
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A 45-year-old businessman returns from a trip to West Africa with headaches and intermittent fevers. Thick and thin films are sent to the lab and a diagnosis is made of malaria. The patient is started on treatment but his condition deteriorates and he develops jaundice, renal failure and haemoglobinuria.
Which of the following is the MOST likely causative organism? Select ONE answer only.Your Answer: Plasmodium malariae
Correct Answer: Plasmodium falciparum
Explanation:Malaria is an infectious disease transmitted by female of theAnophelesgenus of mosquito. It is a parasitic infection caused by the genusPlasmodium. Five species are recognized as causing disease in humans;Plasmodium falciparum,Plasmodium ovale,Plasmodium vivax,Plasmodium malariaeandPlasmodium knowlesi.
The classic symptom of malaria is the malarial paroxysm, a cyclical occurrence of a cold phase, where the patient experiences intense chills, a hot stage, where the patient feels extremely hot and finally a sweating stage, where the fever declines and the patient sweats profusely. On examination the patient may show signs of anaemia, jaundice and have hepatosplenomegaly without evidence of lymphadenopathy.Plasmodium falciparum is the most serious form and is responsible for most deaths. Severe or complicated malaria is suggested by the presence of impaired consciousness, seizures, hypoglycaemia, anaemia, renal impairment, respiratory distress and spontaneous bleeding.
Plasmodium falciparum is the most likely type in this case in view of the presentation.
Haemoglobinuria and renal failure following treatment is suggestive of blackwater fever, which is caused byPlasmodium falciparum. An autoimmune reaction between the parasite and quinine causes haemolysis, haemoglobinuria, jaundice and renal failure. This can be fatal.
The benign malarias: P.vivax, P. malariae and P.ovale are usually treated with chloroquine. A course of primaquine is also required in P.vivax and P.ovale infection. Artesunate is the drug treatment of choice for Plasmodium falciparum malaria. Quinine can still be used where artesunate is not available. Often combination therapy with drugs such as doxycycline or fansidar is also required. -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 85
Incorrect
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One of the benefits of wound healing through first intention is:
Your Answer: Reduced risk of foreign body in wound
Correct Answer: Minimisation of scar tissue formation
Explanation:Primary wound healing, or healing by first intention, occurs within hours of repairing a full-thickness surgical incision. This surgical insult results in the mortality of a minimal number of cellular constituents. Healing by first intention can occur when the wound edges are opposed, the wound is clean and uninfected and there is minimal loss of cells and tissue i.e. surgical incision wound. The wound margins are joined by fibrin deposition, which is subsequently replaced by collagen and covered by epidermal growth.
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This question is part of the following fields:
- Pathology
- Wound Healing
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Question 86
Correct
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A patient in the Emergency Department had a diagnosis of diabetic ketoacidosis (DKA) and you commence an insulin infusion. Which of these statements concerning endogenous insulin is true?
Your Answer: Insulin has a short half-life of around 5-10 minutes
Explanation:Insulin, a peptide hormone, is produced in the pancreas by the beta-cells of the islets of Langerhans.
The beta-cells first synthesise an inactive precursor called preproinsulin which is converted to proinsulin by signal peptidases, which remove a signal peptide from the N-terminus.
Proinsulin is converted to insulin by the removal of the C-peptide.
Insulin has a short half-life in the circulation of about 5-10 minutes.
Glucagon and parasympathetic stimulation stimulates insulin release. -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 87
Correct
-
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: 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 88
Incorrect
-
The least likely feature expected to be seen in a lesion of the frontal lobe is which of the following?
Your Answer: Expressive dysphasia
Correct Answer: Loss of two-point discrimination
Explanation:Lesions in different areas give rise to different symptoms.
Lesions of the parietal lobe give rise to loss of two-point discrimination.
Lesions to Broca’s area give rise to expressive dysphasia results from damage
Lesions to the primary motor cortex give rise to contralateral weakness of the face and arm.
Lesions to the prefrontal cortex give rise to personality change.
Lesions to the frontal eye field give rise to conjugate eye deviation towards side of lesion. -
This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 89
Incorrect
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A 15-year-old girl took 20 tablets of paracetamol almost 4 hours ago after her mother for refused to provide her permission for her to go on a girl's trip. The girl is healthy and has no known comorbidities or drug history. Which one of the following is TRUE regarding paracetamol?
Your Answer: It is thought to work by selectively inhibiting COX-1 receptors in the brain and spinal cord
Correct Answer: It is excreted renally
Explanation:Acetaminophen is an acetanilide derivative and is a widely used non-prescription analgesic and antipyretic medication for mild-to-moderate pain and fever.
The route of elimination: Paracetamol is metabolised extensively in the liver and excreted in the urine mainly as inactive glucuronide and sulfate conjugates, <5% is excreted as free (unconjugated) acetaminophen, and >90% of the dose administered is excreted within 24 hours.
It is thought to work by selectively inhibiting COX-1 receptors in the brain and spinal cord: It is categorized by the FDA as an NSAID as it is believed to selectively inhibit cyclo-oxygenase 3 (COX-3) receptors in the brain and spinal cord.
COX-3 is a unique variant of the more known COX-1 and COX-2. It is responsible for the production of prostaglandins in central areas, which sensitizes free nerve endings to the chemical mediators of pain. Therefore, by selectively inhibiting COX-3, paracetamol effectively reduces pain sensation by increasing the pain threshold.
Toxicity is primarily due to glutathione production: Acetaminophen metabolism by the CYP2E1 pathway releases a toxic metabolite known as N-acetyl-p-benzoquinoneimine (NAPQI). NAPQI primarily contributes to the toxic effects of acetaminophen. NAPQI is an intermediate metabolite that is further metabolized by fast conjugation with glutathione. The conjugated metabolite is then excreted in the urine as mercapturic acid. High doses of acetaminophen (overdoses) can lead to hepatic necrosis due to depleting glutathione and high binding levels of reactive metabolite (NAPQI) to important parts of liver cells.
Acetaminophen can be administered orally, rectally, or intravenously. It is predominantly metabolized in the liver, and the elimination half-life is 1-3 hours after a therapeutic dose. But maybe greater than 12 hours after an overdose.
It is primarily metabolized via the cytochrome p450 enzyme system: It is predominantly metabolized in the liver by three main metabolic pathways:
1. Glucuronidation (45-55%)
2. Sulphate conjugation (30-35%)
3. N-hydroxylation via the hepatic cytochrome p450 enzyme system (10-15%) -
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 90
Incorrect
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A 29-year-old female with a swollen red finger presents to your clinic and you suspect that the underlying process is of acute inflammation. You request for some bloods investigations.
Which statement about histamine as a chemical mediator of the acute inflammatory response is TRUE?Your Answer: It is a major factor is endotoxic shock
Correct Answer: It increases vascular permeability
Explanation:Histamine increases vascular permeability in the acute inflammatory response.
Histamine causes vasodilation.
It is released from Mast cells and basophils, eosinophils and platelets.
Mast cells and basophils are its primary source
Nitric oxide (not histamine) is a major factor in endotoxic shock
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 91
Incorrect
-
The arterial blood gas (ABG) of a 56-year-old woman shows type A lactic acidosis.
What is the most likely cause of her lactic acidosis?
Your Answer: Cyanide poisoning
Correct Answer: Left ventricular failure
Explanation:Lactic acidosis is a common finding in critically ill patients and commonly associated with other serious underlying pathologies. It occurs when pH is <7.35 and lactate is >5 mmol/L. Anion gap is increased in lactic acidosis.
Acquired lactic acidosis is classified into two subtypes:
Type A: lactic acidosis due to tissue hypoxia and
Type B: due to non-hypoxic processes affecting the production and elimination of lactateSome causes of type A and type B lactic acidosis include:
Type A lactic acidosis
Left ventricular failure
Severe anaemia
Shock (including septic shock)
Asphyxia
Cardiac arrest
CO poisoning
Respiratory failure
Severe asthma and COPDType B lactic acidosis:
Regional hypoperfusion
Renal failure
Liver failure
Sepsis (non-hypoxic sepsis)
Thiamine deficiency
Alcoholic ketoacidosis
Diabetic ketoacidosis
Cyanide poisoning
Methanol poisoning
Biguanide poisoning -
This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 92
Incorrect
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A 30-year-old man present to the ED with abdominal pain, nausea and vomiting. It has been present for the past two days.
Which of the following statements regarding diarrhoea and vomiting is true?
Your Answer: Rotavirus is only spread via the faeco-oral route
Correct Answer: E.Coli can cause diarrhoea and renal failure
Explanation:Escherichia coli strain 0157 causes enterohaemorrhagic diarrhoea and can lead to renal failure, haemolytic anaemia and thrombocytopenia.
Norwalk virus is an RNA virus.
Although transmission of rotavirus is primarily through the faeco-oral route, airborne spread has been seen in some cases.
Cryptosporidium are protozoa with acid fast walls and are resistant to both chlorine treatment and conventional filtering methods.
There is no therapy effective in treating cryptosporidium diarrhoea as the protozoa is not susceptible to antibiotics.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 93
Incorrect
-
Which of the following statements about neutrophils is TRUE:
Your Answer: Neutrophils comprise about 30% of circulating white cells.
Correct Answer: Neutrophils are typically the first immune cell to arrive to a site of injury.
Explanation:Neutrophils are the most numerous peripheral blood leukocytes, accounting for 50-70 percent of all circulating white cells. Neutrophils have a compact nucleus with two to five lobes and a pale cytoplasm with an irregular shape containing numerous fine pink-blue or grey-blue granules. The granules are classified as primary, which emerges during the promyelocyte stage, and secondary, which develop at the myelocyte stage and predominate in the mature nucleus.
The lifespan of neutrophils in the blood is only 6 – 10 hours. In response to tissue damage, cytokines and complement proteins, neutrophils migrate from the bloodstream to the site of insult within minutes, where they destroy pathogens by phagocytosis.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 94
Incorrect
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A 34-year-old man presents with loss of vision in his left eye due to an episode of optic neuritis. Upon history taking, it was noted that he has a history of multiple sclerosis.
Which of the following anatomical points in the visual pathway has the lesion occurred?Your Answer: Upper optic radiation
Correct Answer: Optic nerve
Explanation:A lesion in the optic nerve causes ipsilateral monocular visual loss.
Optic neuritis is an inflammatory demyelination of the optic nerve that is highly associated with multiple sclerosis. The two most common symptoms of optic neuritis are vision loss and eye pain. -
This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 95
Incorrect
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When the breast cancer of a 60-year old patient metastasizes and compresses the intervertebral foramina between the fourth and fifth cervical vertebrae, as well as the fourth and fifth thoracic vertebrae, this causes back pain. Which pair of nerves is most likely affected?
Your Answer: Fourth cervical and fifth thoracic nerves
Correct Answer: Fifth cervical and fourth thoracic nerves
Explanation:The fifth cervical nerve passes between the fourth and fifth cervical vertebrae, and the fourth thoracic nerve passes between the fourth and fifth thoracic vertebrae. Therefore, when the cancer metastasizes in this area, they are most likely affected.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 96
Correct
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Anatomical barriers to infection include all of the following EXCEPT:
Your Answer: Mucociliary escalator in the gastrointestinal tract
Explanation:Anatomical barriers to infection include:tight junctions between cells of the skin and mucosal membranesthe flushing action of tears, saliva and urinethe mucociliary escalator in the respiratory tract (together with the actions of coughing and sneezing)the acidic pH of gastric and vaginal secretionsthe acidic pH of the skin (maintained by lactic acid and fatty acids in sebum)enzymes such as lysozyme found in saliva, sweat and tearspepsin present in the stomachbiological commensal flora formed on the skin and the respiratory, gastrointestinal and genitourinary tracts which protect the host by competing with pathogenic bacteria for nutrients and attachment sites and by producing antibacterial substances
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This question is part of the following fields:
- Microbiology
- Principles
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Question 97
Incorrect
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In the emergency room, a 28-year-old woman complains of wobbly and slurred speech, is unable to do the heel-shin test, and has nystagmus. The following signs are most likely related to damage to which of the following areas:
Your Answer: Occipital lobe
Correct Answer: Cerebellum
Explanation:Cerebellar injury causes delayed and disorganized motions. When walking, people with cerebellar abnormalities sway and stagger.
Damage to the cerebellum can cause asynergia, the inability to judge distance and when to stop, dysmetria, the inability to perform rapid alternating movements or adiadochokinesia, movement tremors, staggering, wide-based walking or ataxic gait, a proclivity to fall, weak muscles or hypotonia, slurred speech or ataxic dysarthria, and abnormal eye movements or nystagmus.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 98
Incorrect
-
In relation to ketamine, which of the following statements is TRUE:
Your Answer: It is contraindicated in children.
Correct Answer: It is usually associated with tachycardia, increased blood pressure and increased cardiac output.
Explanation:Ketamine has hypnotic, analgesic and local anaesthetic properties. Major adverse effects include Hypertension, Increased cardiac output, Increased ICP, Tachycardia, Tonic-clonic movements, Visual hallucinations and Vivid dreams.
Ketamine is mostly utilized in paediatric anaesthesia, especially when repeated dosing is necessary (such as for serial burns dressings). Ketamine has little effect on respiratory drive, and protective airway reflexes are unaffected. Ketamine is also a bronchial smooth muscle relaxant, hence it plays a unique function in the treatment of severe asthma. -
This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 99
Correct
-
A 78-year-old man complains of lumps in his neck. Several large, non-tender cervical lymph nodes are discovered during your examination.
You arrange for some blood tests, and the results reveal that he has lymphocytosis with a count of 16 x 10 9 /l.
In this case, what is the most likely diagnosis?Your Answer: Chronic lymphocytic leukaemia
Explanation:The most common type of adult leukaemia is chronic lymphocytic leukaemia (CLL). It develops as a result of relatively mature lymphocytes clonally proliferating. The B-cell lineage accounts for approximately 95% of cases. CLL is primarily a disease of adult men, with men over the age of 50 accounting for more than 75% of CLL patients.
It is the most indolent form of chronic leukaemia, and it is frequently discovered by chance when blood counts are taken for other reasons, such as ‘well man’ screening tests. The patient may develop lymphadenopathy, hepatosplenomegaly, anaemia, and infections as the disease progresses.
The following are examples of CLL laboratory findings:
Clonal B cell lymphocytosis (diagnosed at greater than 5 x 109/l, but can reach 300 x 109/l)
In advanced disease, normocytic, normochromic anaemia is present.Patients with autoimmune-related haemolytic anaemias have a positive direct antiglobulin test (DAT).
Although bone marrow aspiration is not always required, it can aid in the diagnosis of CLL. If there has been rapid lymph node enlargement, a lymph node biopsy is required to rule out Richter’s syndrome. This is the transition from low-grade lymphoma to high-grade lymphoma, which is characterised by fever, weight loss, and pain.
Although there is no cure for CLL, it can be managed with chemotherapy regimens that help patients live longer. Early treatment has no benefit, and the standard treatment for early disease is to watch and wait, with examinations and blood counts every 3 to 12 months. Chemotherapy is usually reserved for patients who have a disease that is active and causing symptoms.
The following is the overall prognosis for CLL:
1/3 will not require treatment and will live a long time.
1/3 will go through an indolent phase before the disease progresses.
1/3 of patients will have an aggressive disease that requires immediate treatment. -
This question is part of the following fields:
- Haematology
- Pathology
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Question 100
Incorrect
-
Regarding the lumbar plexus, which of the following is a direct muscular branch?
Your Answer: Nerve to obturator internus
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 101
Incorrect
-
Renal potassium excretion is promoted by all but which one of the following:
Your Answer: Increased tubular flow rate
Correct Answer: Increased intracellular magnesium
Explanation:Aldosterone: A rise in [K+] in the extracellular fluid of the adrenal cortex directly stimulates aldosterone release. Aldosterone promotes the synthesis of Na+/K+ATPases and the insertion of more Na+/K+ATPases into the basolateral membrane, and also stimulates apical sodium and potassium channel activity, overall acting to increase sodium reabsorption and potassium secretion.
pH changes: Potassium secretion is reduced in acute acidosis and increased in acute alkalosis. A higher pH increases the apical K+channel activity and the basolateral Na+/K+ATPase activity – both changes that promote K+secretion.
Flow rates: Increased flow rates in the collecting duct reduce K+concentration in the lumen and therefore enhance K+secretion. Increased flow also activates BK potassium channels, and ENaC channels which promote potassium secretion and sodium reabsorption respectively.
Sodium delivery: Decreased Na+delivery to the collecting ducts results in less Na+reabsorption and hence a reduced gradient for K+secretion.
Magnesium: Intracellular magnesium can bind and block K+channels inhibiting K+secretion into the tubules. Therefore magnesium deficiency reduces this inhibitory effect and so allows more potassium to be secreted into tubules and can cause hypokalaemia. -
This question is part of the following fields:
- Physiology
- Renal
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Question 102
Incorrect
-
Which of the following intravenous induction drugs results in the highest drop in blood pressure:
Your Answer: Etomidate
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 103
Incorrect
-
A 73-year-old woman arrives at the emergency department 48 hours after being discharged from the hospital after a two-week stay for sepsis treatment. She has fever, productive cough with thick green sputum, and shortness of breath. An X-ray shows left lower lobe pneumonia. Which of the bacteria listed below is more likely to be the causative agent:
Your Answer: Streptococcus pneumoniae
Correct Answer: Pseudomonas aeruginosa
Explanation:Hospital-acquired pneumonia (HAP), or nosocomial pneumonia, is a lower respiratory infection that was not incubating at the time of hospital admission and that presents clinically 2 or more days after hospitalization. Pneumonia that presents sooner should be regarded as community acquired pneumonia. VAP refers to nosocomial pneumonia that develops among patients on ventilators. Ventilator-associated pneumonia (VAP) is defined as pneumonia that presents more than 48 hours after endotracheal intubation.
Common bacteria involved in hospital-acquired pneumonia (HAP) include the following [10] :
Pseudomonas Aeruginosa
Staphylococcus aureus, including methicillin-susceptible S aureus (MSSA) and methicillin-resistant S aureus (MRSA)
Klebsiella pneumoniae
Escherichia coli -
This question is part of the following fields:
- Infections
- Microbiology
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Question 104
Incorrect
-
Which of the following is NOT a characteristic of megaloblastic anaemia?
Your Answer: Increased lactate dehydrogenase (LDH) level
Correct Answer: Raised reticulocyte count
Explanation:The LDH level is usually markedly increased in severe megaloblastic anaemia. Reticulocyte counts are inappropriately low, representing a lack of production of RBCs due to massive intramedullary haemolysis. These findings are characteristics of ineffective haematopoiesis that occurs in megaloblastic anaemia as well as in other disorders such as thalassemia major.
The common feature in megaloblastosis is a defect in DNA synthesis in rapidly dividing cells. To a lesser extent, RNA and protein synthesis are impaired. Unbalanced cell growth and impaired cell division occur since nuclear maturation is arrested. More mature RBC precursors are destroyed in the bone marrow prior to entering the bloodstream (intramedullary haemolysis). -
This question is part of the following fields:
- Haematology
- Pathology
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Question 105
Correct
-
Angiotensin II is part of the RAAS system. One of its effects is the constriction of efferent arterioles. Which of the following best describes the effect of angiotensin II- mediated constriction of efferent arterioles?
Your Answer: Decreased renal plasma flow, increased filtration fraction, increased GFR
Explanation:The Renin-Angiotensin-Aldosterone System (RAAS) is a hormone system composed of renin, angiotensin, and aldosterone. Those hormones are essential for the regulation of blood pressure and fluid balance.
Cases of hypotension, sympathetic stimulation, or hyponatremia can activate the Renin-angiotensin-aldosterone system (RAAS). The following process will then increase the blood volume and blood pressure as a response.
When renin is released it will convert the circulating angiotensinogen to angiotensin I. The ACE or angiotensin-converting enzyme will then catalyst its conversion to angiotensin II, which is a potent vasoconstrictor. Angiotensin II can constrict the vascular smooth muscles and the efferent arteriole of the glomerulus.
The efferent arteriole is a blood vessel that delivers blood away from the capillaries of the kidney. The angiotensin II-mediated constriction of efferent arterioles increases GFR, reduces renal blood flow and peritubular capillary hydrostatic pressure, and increases peritubular colloid osmotic pressure, as a response to its action of increasing the filtration fraction.
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 106
Incorrect
-
A 27-year-old man presents with a laceration of his forearm that severed the nerve that innervates flexor carpi radialis.
Which of the following nerves has been damaged in this case? Select ONE answer only.Your Answer: The radial nerve
Correct Answer: The median nerve
Explanation:Flexor carpi radialis is innervated by the median nerve.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 107
Correct
-
A 53-year-old male has presented to your clinic with the complaint of a rash on his right forearm. On examination, you discover small reddish-purple spots on the skin measuring less than 2-3 mm. They do not blanch on applying pressure.
Which one of the following best fits the description given above?Your Answer: Petechiae
Explanation:Petechiae are small red or purple spots on the skin measuring less than 3 mm, caused by minor haemorrhages which do not blanch on applying pressure.
Purpura measures between 3mm and 1 cm in diameter, while ecchymoses are greater than 1 cm in diameter. Both are caused due to haemorrhage.Erythema is the generalised redness of the skin.
A macule is a flat, discoloured area of the skin measuring less than 1 cm in diameter.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 108
Incorrect
-
A patient presents with severe vomiting. They take a maintenance dose of 12.5 mg of prednisolone daily for their COPD. They are unable to swallow or keep down tablets at present, and you plan on converting them to IV hydrocortisone.
What dose of hydrocortisone is equivalent to this dose of prednisolone? Select ONE answer only.Your Answer: 25 mg
Correct Answer: 50 mg
Explanation:Prednisolone is four times more potent than hydrocortisone, and therefore, a dose of 12.5 mg would be equivalent to 50 mg of hydrocortisone.
The following table summarises the relative potency of the main corticosteroids compared with hydrocortisone:
Corticosteroid
Potency relative to hydrocortisone
Prednisolone
4 times more potent
Triamcinolone
5 times more potent
Methylprednisolone
5 times more potent
Dexamethasone
25 times more potent -
This question is part of the following fields:
- Endocrine Pharmacology
- Pharmacology
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Question 109
Incorrect
-
In the emergency department, a 50-year-old female appears with a lack of sensation over the front two-thirds of her tongue. Taste and salivation are both present. The patient might have damage which of her nerves?
Your Answer: Glossopharyngeal nerve
Correct Answer: Lingual nerve
Explanation:The lingual nerve, a branch of the mandibular nerve, transmits sensation to the anterior two-thirds of the tongue.
The chorda tympani, a branch of the facial nerve, transmits taste to the front two-thirds of the tongue as well as secretomotor innervation to the submandibular and sublingual glands.
As a result, any damage to the lingual nerve can cause changes in salivary secretion on the affected side, as well as a loss of taste in the anterior two-thirds of the tongue and temporary or permanent sensory changes in the anterior two-thirds of the tongue and the floor of the mouth.
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This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
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Question 110
Incorrect
-
Which of the following nerves supply the superficial head of the flexor pollicis brevis muscle?
Your Answer: The palmar digital branch of the median nerve
Correct Answer: The recurrent branch of the median nerve
Explanation:The two heads of the flexor pollicis brevis usually differ in their innervation. The superficial head of flexor pollicis muscle receives nervous supply from the recurrent branch of the median nerve, whereas the deep head receives innervation from the deep branch of the ulnar nerve, derived from spinal roots C8 and T1.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 111
Correct
-
Which of the following muscles acts as an extensor of the shoulder joint?
Your 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 112
Incorrect
-
A patient presents with an adducted eye at rest which cannot abduct past the midline, which of the following cranial nerves is most likely to be affected:
Your Answer: Ophthalmic division of the trigeminal nerve
Correct Answer: Abducens nerve
Explanation:Abducens nerve 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 113
Incorrect
-
Regarding the abductor pollicis longus, which of the following statements is true?
Your Answer: Its tendons form the medial border of the anatomical snuffbox
Correct Answer: It extends the thumb at the carpometacarpal joint
Explanation:Abductor pollicis longus is a muscle found in the posterior compartment of the forearm. It is one of the five deep extensors in the forearm, along with the supinator, extensor pollicis brevis, extensor pollicis longus and extensor indicis.
Abductor pollicis longus is innervated by the posterior interosseous nerve (C7, C8), which is a continuation of the deep branch of the radial nerve. The radial nerve is a branch of the posterior cord of the brachial plexus.
Blood supply to the abductor pollicis longus muscle comes from the interosseous branches of the ulnar artery.
Acting alone or with abductor pollicis brevis, abductor pollicis longus pulls the thumb away from the palm. More specifically, it produces (mid-) extension and abduction of the thumb at the first metacarpophalangeal joint. This action is seen in activities such as bowling and shovelling.
Working together with the long and short extensors of the thumb, the muscle also helps to fully extend the thumb at the metacarpophalangeal joint. This action is important for loosening the hand grip, for example, when letting go of objects previously being held. Abductor pollicis longus also helps to abduct the hand (radial deviation) at the radiocarpal joint.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 114
Correct
-
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: 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 115
Incorrect
-
A 45-year-old woman presents with persistent palpitations for the past two days. She has a good haemodynamic balance. An ECG is performed, which reveals that she has atrial flutter. The patient is examined by a cardiology registrar, who recommends using a 'rate control' strategy while she waits for cardioversion.
Which of the drugs listed below is the best fit for this strategy?Your Answer: Digoxin
Correct Answer: Bisoprolol
Explanation:In atrial flutter, ventricular rate control is usually used as a stopgap measure until sinus rhythm can be restored. A beta-blocker (such as bisoprolol), diltiazem, or verapamil can be used to lower the heart rate.
Electrical cardioversion, pharmacological cardioversion, or catheter ablation can all be used to restore sinus rhythm. Cardioversion should not be attempted until the patient has been fully anticoagulated for at least three weeks if the duration of atrial flutter is unknown or has lasted for more than 48 hours. Emergency electrical cardioversion is the treatment of choice when there is an acute presentation with haemodynamic compromise. For the treatment of recurrent atrial flutter, catheter ablation is preferred.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 116
Incorrect
-
The following structures all lie anteriorly to the oesophagus EXCEPT for the:
Your Answer: Pericardium
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 117
Correct
-
Noradrenaline exhibits its positive inotropic effect by which of the following mechanisms:
Your Answer: Binds to beta1-receptors and causes increased Ca2+ entry via L-type channels during the action potential
Explanation:Noradrenaline (the sympathetic neurotransmitter) is a positive inotrope; it binds to β1-adrenoceptors on the membrane and causes increased Ca2+entry via L-type channels during the AP and thus increases Ca2+release from the SR. Noradrenaline also increases Ca2+sequestration into the SR and thus more Ca2+is available for the next contraction. Cardiac glycosides (e.g. digoxin) slow the removal of Ca2+from the cell by inhibiting the membrane Na+pump which generates the Na+gradient required for driving the export of Ca2+; consequently the removal of Ca2+from the myocyte is slowed and more Ca2+is available for the next contraction. Acidosis is negatively inotropic, largely because H+competes for Ca2+binding sites.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 118
Incorrect
-
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: Selective adrenal venous sampling
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 miss
Familial aldosteronism – a rare group of inherited conditions affecting the adrenal glands
The causes of secondary hyperaldosteronism include:
Drugs – diuretics
Obstructive renal artery disease – renal artery stenosis and atheroma
Renal vasoconstriction – occurs in accelerated hypertension
Oedematous disorders – heart failure, cirrhosis and nephrotic syndrome
Patients are often asymptomatic. When clinical features are present, the classically described presentation of hyperaldosteronism is with:
Hypertension
Hypokalaemia
Metabolic alkalosis
Sodium levels can be normal or slightly raised
Other, less common, clinical features include:
Lethargy
Headaches
Muscle weakness (from persistent hypokalaemia)
Polyuria and polydipsia
Intermittent paraesthesia
Tetany 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. BAH
Other investigations that can help to distinguish between an adrenal adenoma and adrenal hyperplasia include:
CT scan
MRI scan
Selective adrenal venous sampling -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 119
Correct
-
Regarding penicillin antibiotics, which of the following statements is CORRECT:
Your Answer: Patients with a history of atopy are at higher risk of hypersensitivity reactions.
Explanation:Allergic reactions to penicillins occur in 1 – 10% of exposed individuals; anaphylactic reactions occur in fewer than 0.05% of treated patients. Patients with a history of atopic allergy are at higher risk of anaphylactic reactions to penicillins. Patients with a history of anaphylaxis, urticaria, or rash immediately after penicillin use should not receive a penicillin or other beta-lactam antibiotics; about 0.5 – 6.5 % of penicillin-sensitive patients will also be allergic to the cephalosporins.
Patients with a history of a more minor rash (i.e. non-confluent, non-pruritic rash restricted to a small area of the body) or delayed reaction (rash occurring more than 72 hours after penicillin administration), may not be truly allergic and may be considered for penicillin or beta-lactam treatment in severe infection (although possibility of allergy should be borne in mind). Other beta-lactam antibiotics (including cephalosporins) can be used in these patients.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 120
Incorrect
-
A 65-year-old man presents with a red, hot, swollen great toe. A diagnosis of acute gout is made. His past medical history includes heart failure and type 2 diabetes mellitus.
Which of the following is the most appropriate medication to use in the treatment of his gout? Select ONE answer only.Your Answer: Prednisolone
Correct Answer: Colchicine
Explanation:In the absence of any contra-indications, high-dose NSAIDs are the first-line treatment for acute gout. Naproxen 750 mg as a stat dose followed by 250 mg TDS is a commonly used and effective regime.
Aspirin should not be used in gout as it reduces the urinary clearance of urate and interferes with the action of uricosuric agents. Naproxen, Diclofenac or Indomethacin are more appropriate choices.
Allopurinol is used prophylactically, preventing future attacks by reducing serum uric acid levels. It should not be started in the acute phase as it increases the severity and duration of symptoms.
Colchicine acts on the neutrophils, binding to tubulin to prevent neutrophil migration into the joint. It is as effective as NSAIDs in relieving acute attacks. It also has a role in prophylactic treatment if Allopurinol is not tolerated.
NSAIDs are contra-indicated in heart failure as they can cause fluid retention and congestive cardiac failure. Colchicine is the preferred treatment in patients with heart failure or those who are intolerant of NSAIDs. -
This question is part of the following fields:
- Musculoskeletal Pharmacology
- Pharmacology
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Question 121
Incorrect
-
Which of the following statements is correct with regards to Horner's syndrome?
Your Answer: Horner's syndrome results from damage to the oculomotor nerve.
Correct Answer: Miosis occurs due to paralysis of the dilator pupillae muscle.
Explanation:The characteristics of Horner’s syndrome are pupil constriction, partial ptosis and anhidrosis.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 122
Incorrect
-
Stimulation of J receptors located on alveolar and bronchial walls results in all of the following EXCEPT for:
Your Answer: Laryngeal constriction
Correct Answer: Tachycardia
Explanation:Juxtapulmonary or ‘J’ receptors are located on alveolar and bronchial walls close to the capillaries. Their afferents are small unmyelinated C-fibres or myelinated nerves in the vagus nerve. Activation causes depression of somatic and visceral activity by producing apnoea or rapid shallow breathing, a fall in heart rate and blood pressure, laryngeal constriction and relaxation of skeletal muscles via spinal neurones. J receptors are stimulated by increased alveolar wall fluid, pulmonary congestion and oedema, microembolism and inflammatory mediators. J receptors are thought to be involved in the sensation of dyspnoea in lung disease.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 123
Incorrect
-
A patient complains of headache and visual loss. CT scan demonstrates a lesion of the temporal lobe. What type of visual field defect would you most expect to see in this patient:
Your Answer: Contralateral homonymous hemianopia
Correct Answer: Contralateral homonymous superior quadrantanopia
Explanation:Axons from the lateral geniculate nucleus (LGN) carry visual information, via the upper and lower optic radiations, to the visual cortex in the occipital lobe:
The upper optic radiation carries fibres from the superior retinal quadrants (corresponding to the inferior visual field quadrants) and travels through the parietal lobe to reach the visual cortex.
The lower optic radiation carries fibres from the inferior retinal quadrants (corresponding to the superior visual field quadrants) and travels through the temporal lobe to reach the visual cortex of the occipital lobe. -
This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 124
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: It combines with haemoglobin to form carbaminohaemoglobin
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 125
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: 300
No. of patients who took Ticagrelor and suffered a stroke: 30
No. of patients who took Warfarin: 500
No. of patients who took Warfarin and suffered a stroke: 20
Compute for the risk ratio of a stroke.Your Answer: -0.06
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/ARC
RR = (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. -
This question is part of the following fields:
- Evidence Based Medicine
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Question 126
Incorrect
-
What is the average healing time for a femoral shaft fracture under normal circumstances? Choose ONE answer.
Your Answer: 6-8 weeks
Correct Answer: 12 weeks
Explanation:The process of fracture healing occurs naturally after traumatic bone disruption and begins with haemorrhage, then progresses through Inflammatory, reparative, and remodelling stages
Average healing times of common fractures are:
Femoral shaft: 12 weeks
Tibia: 10 weeks
Phalanges: 3 weeks
Metacarpals: 4-6 weeks
Distal radius: 4-6 weeks
Humerus: 6-8 weeks -
This question is part of the following fields:
- General Pathology
- Pathology
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Question 127
Correct
-
A 70-year-old man has severe diarrhoea one week after taking co-amoxiclav for a chest infection. The diarrhoea is yellow in colour and smell is offensive.
What is the SINGLE MOST likely causative organism?
Your Answer: Clostridium difficile
Explanation:Clostridium difficile, a Gram-positive, anaerobic, spore forming bacteria is present in the gut of approximately 3% of healthy adults (2012 UK HPA estimates). Following use of broad spectrum antibiotics, which alter normal gut flora, Clostridium difficile associated diarrhoea (CDAD) occurs.
About 80% of Clostridium difficile infections are seen in people over the age of 65 and its main clinical features are:
Abdominal cramps, severe bloody and/or watery diarrhoea, offensive smelling diarrhoea, and fever. -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 128
Incorrect
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A 29-year-old volunteer returns from a recent trip to the middle east with profuse watery diarrhoea. You make a diagnosis of cholera and organize a hospital admission for rehydration with intravenous fluids.
What is the mechanism of action of cholera toxin?
Your Answer: Activation of GTPAse
Correct Answer: ADP-ribosylation of the G regulatory protein
Explanation:Cholera is caused by Vibrio cholerae, a motile, Gram-negative, curved bacillus. It is transmitted through water and food (especially seafood) and is primarily a disease seen in developing countries where there is poor sanitation and lack of safe water supplies.
The cholera toxin leads to stimulation of adenyl cyclase, ADP-ribosylation of the G regulatory protein, inactivation of GTPase leading to active outpouring of NaCl.
The cholera toxin consists of an A (the toxin) and B subunit. The B subunit attaches to the gut mucosa and presents the A subunit to the cell. The toxin stimulates adenyl cyclase by irreversible ADP-ribosylation of the GTP binding domain of adenyl cyclase leading to the opening of chloride channels resulting in an outpouring of NaCl and water into the lumen of the gut and causing secretory diarrhoea.
Incubation period is between 2 and 5 days, but can be as short as just a few hours.
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 129
Incorrect
-
Compression of this nerve can cause weakness in the left leg while walking and thigh adduction weakness at the hip joint.
Your Answer: Inferior gluteal nerve
Correct Answer: Obturator nerve
Explanation:The obturator nerve is a sensory and motor nerve that emerges from the lumbar plexus and innervates the thigh.
This nerve supplies motor innervation to the medial compartment of the thigh, making it necessary for thigh adduction.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 130
Correct
-
A 38-year-old man returns from an overseas business trip with a fever and a headache. Following investigations a diagnosis of Plasmodium falciparum malaria is made.
Which of the following statements regarding Plasmodium falciparum malaria is true? Select ONE answer only.Your Answer: There may be a continuous fever
Explanation:Plasmodium falciparum malaria is transmitted by female of the Anopheles genus of mosquito. The Aedes genus is responsible for transmitting diseases such as dengue fever and yellow fever.
Plasmodium falciparumis found globally but is mainly found in sub-Saharan Africa.
The incubation period of Plasmodium falciparum malaria is 7-14 days.
Sporozoites invade hepatocytes. Within the hepatocyte asexual reproduction occurs producing merozoites, which are released into the blood stream and invade the red blood cells of the host.
Artesunate is the drug treatment of choice for Plasmodium falciparum malaria. Quinine can still be used where artesunate is not available. Often combination therapy with drugs such as doxycycline or fansidar is also required.
The classic symptom of malaria is the malarial paroxysm, a cyclical occurrence of a cold phase, where the patient experiences intense chills, a hot stage, where the patient feels extremely hot and finally a sweating stage, where the fever declines and the patient sweats profusely. There may also, however, be a continuous fever. -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 131
Incorrect
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A 65-year-old man presents with cough and shortness of breath. His sputum is rusty in colour and is suffering from a fever. Upon examination, it was noted that he has crackles in the right upper lobe. A chest X-ray showed the presence of a right upper lobe cavitation.
Among the following microorganisms, which is considered to be mostly associated with a cavitating upper lobe pneumonia?Your Answer: Streptococcus pneumoniae
Correct Answer: Klebsiella pneumoniae
Explanation:Klebsiella pneumoniae is among the most common Gram-negative bacteria encountered by physicians worldwide and accounts for 0.5-5.0% of all cases of pneumonia. This organism can cause extensive pulmonary necrosis and frequent cavitation.
It is one of the causes that could be suspected when there is cavitatory pneumonia with or without a bulging fissure sign. Often, there can be extensive lobar opacification with air bronchograms.
A helpful feature which may help to distinguish from pneumococcal pneumonia is that Klebsiella pneumoniae develops cavitation in 30-50% of cases (in comparison, cavitation is rare in pneumococcal pneumonia). This occurs early and progresses quickly.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 132
Incorrect
-
A patient presents to ED complaining of pins and needles over the lateral three and a half digits. You suspect carpal tunnel syndrome. Which of the following clinical features would you most expect to see on examination:
Your Answer: Inability to flex the interphalangeal joint of the thumb
Correct Answer: Inability to touch the pad of the little finger with the thumb
Explanation:Compression of the median nerve in the carpal tunnel will result in weakness and atrophy of the thenar muscles – resulting in weakness of opposition, abduction and flexion of the thumb at the metacarpophalangeal joint and anaesthesia or paraesthesia over the distribution of the palmar digital branch of the median nerve (skin over the palmar surface and fingertips of the lateral three and a half digits). The adductor pollicis muscle is innervated by the ulnar nerve, and abduction of the fingers is produced by the interossei, also innervated by the ulnar nerve. Flexion of the interphalangeal joint of the thumb is produced by the flexor pollicis longus, and flexion of the distal interphalangeal joint of the index finger is produced by the flexor digitorum profundus. Median nerve injury at the wrist will not affect the long flexors of the forearm as these are innervated by the anterior interosseous nerve which arises in the proximal forearm.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 133
Incorrect
-
A dermatological examination on a patient presenting with a lump shows a small visible skin elevation containing an accumulation of pus.
Which one of these best describes the lump you have found on examination?Your Answer: Furuncle
Correct Answer: Pustule
Explanation:A pustule is a small visible skin elevation containing an accumulation of pus.
A carbuncle is a collection of individual boils clustered together.
A bulla is a visible collection of clear fluid measuring greater than 0.5 cm in diameter.
A furuncle, or boil, is a pyogenic infection of the hair follicle commonly caused by infection with Staphylococcus aureus.
A vesicle is a visible collection of fluid measuring less than 0.5 cm in diameter.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 134
Incorrect
-
A 55-year-old female is urgently rushed into the Emergency Department as she complains of chest pain that is worse on breathing, shortness of breath, palpitations, and haemoptysis.
She undergoes a CT pulmonary angiogram, which reveals a large pulmonary embolus. She is immediately started on heparin and shifted to the acute medical ward.
Which of the following does heparin activate?Your Answer: Protein S
Correct Answer: Antithrombin III
Explanation:Heparin works by binding to and activating the enzyme inhibitor antithrombin III.
Antithrombin III inactivates thrombin (factor IIa) by forming a 1:1 complex with thrombin. The heparin-antithrombin III complex also inhibits factor Xa and some other proteases involved with clotting. The heparin-ATIII complex can also inactivate IX, XI, XII, and plasmin.
Heparin is a polymer of glycosaminoglycan. It occurs naturally and is found in mast cells. Clinically, it is used in two forms:
1. Unfractionated: widely varying polymer chain lengths
2. Low molecular weight: Smaller polymers onlyHeparin is not thrombolytic or fibrinolytic. It prevents the progression of existing clots by inhibiting further clotting. The lysis of existing clots relies on endogenous thrombolytics.
Heparin is used for:
1. Prevention and treatment of venous thromboembolism
2. Treatment of disseminated intravascular coagulation
3. Treatment of fat embolism
4. Priming of haemodialysis and cardiopulmonary bypass machines -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 135
Correct
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A patient with a stab wound to the axilla arrives to the emergency department. You notice weakness in elbow flexion and forearm supination during your assessment. Which of these nerves has been affected:
Your Answer: Musculocutaneous nerve
Explanation:The musculocutaneous nerve is relatively protected in the axilla, hence injury to it is uncommon. A stab wound in the axilla is the most prevalent source of damage. Because of the activities of the pectoralis major and deltoid, the brachioradialis, and the supinator muscles, arm flexion and forearm flexion and supination are diminished but not completely lost. Over the lateral part of the forearm, there is a lack of sensation.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 136
Incorrect
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A 59-year-old man presents to the emergency room with chest pain. He was recently released from the hospital after receiving abciximab during coronary angioplasty.
Which of the following is abciximab (ReoPro) mechanism of action?Your Answer: Inhibition of the fibrinolytic action of plasmin
Correct Answer: Antagonism of the glycoprotein IIb/IIIa receptor
Explanation:Abciximab (ReoPro) is a glycoprotein IIb/IIIa receptor antagonist that is a chimeric monoclonal antibody. It is primarily used during and after coronary artery procedures such as angioplasty to inhibit platelet aggregation.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 137
Incorrect
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A 39-year-old man with a long history of depression presents after intentionally overdoing his heart medication. Verapamil immediate-release 240 mg is the tablet he takes for this condition, he says. He took the pills about 30 minutes ago, but his wife discovered him right away and rushed him to the emergency room.
At the moment, he is completely symptom-free. When it comes to this type of overdose, how long does it usually take for symptoms to appear?Your Answer: 15-30 minutes
Correct Answer: 1-2 hours
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.
>10 tablets of verapamil (160 mg or 240 mg immediate or sustained-release capsules) or diltiazem can cause serious toxicity (180 mg, 240 mg or 360 mg immediate or sustained-release capsules)
In children, 1-2 tablets of verapamil or diltiazem (immediate or sustained-release)
Symptoms usually appear within 1-2 hours of ingestion with standard preparations. However, with slow-release preparations, significant toxicity may take 12-16 hours to manifest, with peak effects occurring after 24 hours.
The following are the main clinical features of calcium-channel blocker overdose:
Nausea and vomiting
Hypotension
Bradycardia and first-degree heart block
Myocardial ischaemia and stroke
Renal failure
Pulmonary oedema
HyperglycaemiaThe following are some of the most important bedside investigations to conduct:
Blood glucose
ECG
Arterial blood gas
Other investigations that can be helpful include
Urea & electrolytes
Chest X-ray (pulmonary oedema)
Echocardiography -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 138
Correct
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A man presents to the emergency department with a hand laceration that has damaged the opponens digiti minimi muscle.
All of the following statements regarding the opponens digiti minimi muscle is considered correct, except:Your Answer: It is innervated by the superficial branch of the ulnar nerve
Explanation:Opponens digiti minimi (ODM) is an intrinsic muscle of the hand. It’s a triangular muscle that extends between the hamate bone (carpal bone) and the 5th metacarpal bone. It forms the hypothenar muscle group together with the abductor digiti minimi and flexor digiti minimi brevis, based on the medial side of the palm (hypothenar eminence). These muscles act together in moving the little finger. The opponens digiti minimi is responsible for flexion, lateral rotation and opposition of the little finger.
Its origin is the hook of hamate and flexor retinaculum. It inserts into the medial border of 5th metacarpal bone. It is innervated by the deep branch of the ulnar nerve, which stems from the brachial plexus (C8, T1 spinal nerves).
Its blood supply is by the deep palmar branch of ulnar artery and deep palmar arch, which is the terminal branch of the radial artery. -
This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 139
Incorrect
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You suspected a fungal nail infection in a 50-year-old man who presented with an itchy, scaly rash between his toes and a thicker, discoloured nail on his big toe that has been there for almost one month already. Which of the following tests is most likely to confirm your suspected diagnosis?
Your Answer: Skin swab for microscopy and culture
Correct Answer: Nail clippings for microscopy and culture
Explanation:Nail clippings for microscopy and culture are a diagnostic test for fungal infection. Because some fungi are restricted to the lower parts of the nail, clippings should be taken from the discoloured or brittle parts and cut back as far as possible from the free edge.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 140
Incorrect
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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: Stable neurological condition
Correct 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. -
This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 141
Incorrect
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Which of the following statements is true regarding a pleural aspiration?
Your Answer: The pleural cavity usually contains between 50-100 ml of lubricating fluid
Correct Answer: The needle should be inserted just above the upper border of the chosen rib
Explanation:Pleural aspiration describes a procedure whereby pleural fluid or air may be aspirated via a system inserted temporarily into the pleural space. This may be for diagnostic purposes (usually removing 20–50 ml fluid) or therapeutic to relieve symptoms. In the literature it is varyingly called thoracocentesis, thoracentesis or pleural aspiration.
In determining the correct patient position and site of insertion, it is important for the operator to be aware of the normal anatomy of the thorax and the pathology of the patient. Patient position is dependent on the operator preference and the site of the pathology. In the case of a posterior lying locule, this may be specific to the image-guided spot where fluid is most likely to be obtained. In most circumstances, however, the site of insertion of the needle is either in the triangle of safety or the second intercostal space in the midclavicular line. The patient may therefore either sit upright leaning forward with arms elevated but resting on a table or bed, thereby exposing the axilla, or lying on a bed in a position. The needle is inserted in the space just above the chosen rib to avoid damaging the neurovascular bundle. It is common practice to insert the needle more posteriorly for a pleural aspiration, but it should be noted that the neurovascular bundle may not be covered by the lower flange of the rib in this position and a more lateral or anterior site of insertion is considered safer.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 142
Incorrect
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A 22-year-old man comes to the emergency department with a human bite injury to his hand received from a punch during a fight 3 hours earlier outside a bar. On closer inspection, you discover bite marks on his first and second knuckles. Which of the following is the best treatment option for this patient:
Your Answer: Nil antibiotics at this stage
Correct Answer: Oral co-amoxiclav for 7 days
Explanation:Even if there is no evidence of infection, prophylactic antibiotics should be administered for all human bite wounds that are less than 72 hours old. The first-line therapy is 7 days of co-amoxiclav. In penicillin-allergic people, metronidazole + doxycycline is an option. Streptococcus spp., Staphylococcus aureus, Haemophilus spp., Eikenella corrodens, Bacteroides spp., and other anaerobes are the most prevalent organisms found in human bites.
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This question is part of the following fields:
- Infections
- Microbiology
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Question 143
Incorrect
-
A patent has weakness of humeral flexion and extension. A CT scan reveals that he has suffered damage to the nerve that innervates pectoralis major.
Pectoralis major receives its innervation from which of the following nerves? Select ONE answer only.Your Answer: Lateral pectoral nerve alone
Correct Answer: Lateral and medial pectoral nerves
Explanation:Pectoralis major is a thick, fan-shaped muscle situated in the chest. It makes up the bulk of the chest musculature in the male and lies underneath the breast in the female. It overlies the thinner pectoralis minor muscle.
Superficial muscles of the chest and arm showing pectoralis major (from Gray’s Anatomy)
Pectoralis major has two heads; the clavicular head and the sternocostal head. The clavicular head originates from the anterior border and medial half of the clavicle. The sternocostal head originates from the anterior surface of the sternum, the superior six costal cartilages and the aponeurosis of the external oblique muscle. It inserts into the lateral lip of the bicipital groove of the humerus.
Pectoralis major receives dual innervation from the medial pectoral nerve and the lateral pectoral nerve.
Its main actions are as follows:
Flexes humerus (clavicular head)
Extends humerus (sternocostal head)
Adducts and medially rotates the humerus
Draws scapula anteriorly and inferiorly -
This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 144
Incorrect
-
After a work-related accident, a 33-year old male is taken to the emergency room with difficulty in adduction and flexion of his left arm at the glenohumeral joint. The attending physician is suspects involvement of the coracobrachialis muscle.
The nerve injured in the case above is?Your Answer: The dorsal scapular nerve
Correct Answer: The musculocutaneous nerve
Explanation:The coracobrachialis muscle is innervated by the musculocutaneous nerve (C5-C7) a branch of the lateral cord of the brachial plexus.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 145
Incorrect
-
The common bile duct drains into the duodenum in which of the following regions:
Your Answer: Duodenojejunal flexure
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 146
Incorrect
-
After what time period should intravenous phenytoin be used as second-line treatment of status epilepticus?
Your Answer: 15 minutes
Correct Answer: 25 minutes
Explanation:If seizures recur or fail to respond after initial treatment with benzodiazepines within 25 minutes of onset, phenytoin sodium, fosphenytoin sodium, or phenobarbital sodium should be used.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 147
Incorrect
-
A patient has a cardiac output of 4.8 L/min and a heart rate of 80 bpm, therefore their stroke volume is:
Your Answer: 40 mL
Correct Answer: 60 mL
Explanation:Cardiac output (CO) = Stroke volume (SV) x Heart rate (HR).
Therefore SV = CO/HR
= 4.8/80
= 0.06 L = 60 mL. -
This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 148
Incorrect
-
If the null hypothesis is wrongly rejected when it is actually true, this is an example of:
Your Answer: A test with nonparametric data
Correct Answer: A test with a type I error
Explanation:A type I error occurs when the null hypothesis is wrongly rejected when it is actually true and we conclude that there is a difference of effect when in reality there is none (a false positive result).
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 149
Correct
-
Regarding airway resistance, which of the following statements is INCORRECT:
Your Answer: In the lower respiratory tract, airway resistance is mostly determined by the smallest bronchioles.
Explanation:Airway resistance is primarily determined by the airway radius according to Poiseuille’s law, and whether the flow is laminar or turbulent. The major site of airway resistance is the medium-sized bronchi. The smallest airways would seem to offer the highest resistance, but they do not because of their branching parallel arrangement.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 150
Incorrect
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A 70-year-old man presents with right-sided hemiplegia and loss of joint position sense, vibratory sense, and discriminatory touch. Upon further physical examination, it was observed that her tongue deviates to the left-hand side. An MRI and CT scan was ordered and results showed that he was suffering a left-sided stroke.
Which of the following is considered the best diagnosis for the case presented above?Your Answer:
Correct Answer: Medial medullary syndrome
Explanation:Medial medullary syndrome is a form of stroke that affects the medial medulla of the brain. It is caused by a lesion in the medial part of the medulla, which is due to an infraction of vertebral arteries and/or paramedian branches of the anterior spinal artery.
It is characterized by contralateral paralysis of the upper and lower limb of the body, a contralateral decrease in proprioception, vibration, and/or fine touch sensation, paresthesias or less commonly dysesthesias in the contralateral trunk and lower limb, and loss of position and vibration sense with proprioceptive dysfunction. Ipsilateral deviation of the tongue due to ipsilateral hypoglossal nerve damage can also be seen.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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SESSION STATS - PERFORMANCE PER SPECIALTY
