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Question 1
Correct
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You need to give your patient antibiotics, so you call microbiology for some advice.Of the following antibacterial drugs, which of them is a protein synthesis inhibitor?
Your Answer: Erythromycin
Explanation:Bacteriostatic antibiotics include erythromycin and other macrolides. They work by attaching to the bacterial ribosome’s 50S subunit, preventing translocation and, as a result, inhibit protein synthesis. Macrolide antibiotics are actively concentrated inside leukocytes and delivered into the infection site as a result.Action Mechanisms- Examples:Cell wall production is inhibitedVancomycinVancomycinCephalosporinsThe function of the cell membrane is disrupted NystatinPolymyxinsAmphotericin B Inhibition of protein synthesisChloramphenicolMacrolidesAminoglycosidesTetracyclinesNucleic acid synthesis inhibitionQuinolonesTrimethoprimRifampicin5-nitroimidazolesSulphonamidesAnti-metabolic activityIsoniazid
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 2
Correct
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Campylobacter jejuni is primarily spread via which of the following routes:
Your Answer: Faecal-oral route
Explanation:Campylobacter spp. are a common cause of acute infective gastroenteritis, particularly in children, with Campylobacter jejuni responsible for 90% of Campylobacter gastroenteritis. Infection typically follows ingestion of contaminated meat (most frequently undercooked poultry), unpasteurised milk or contaminated water, following which the microorganism invades and colonises the mucosa of the small intestine.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 3
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 4
Incorrect
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Question 5
Incorrect
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The weight distribution in a group of patients included in a study was normal. The patients averaged 80 kg in weight. 5 kg was determined to be the standard deviation. Which of the following statements most accurately describes this group of patients:
Your Answer: 95% of the patients will weigh between 75 and 85 kg.
Correct Answer: 68% of the patients will weigh between 75 and 85 kg.
Explanation:We can estimate the range of values that would be anticipated to include particular proportions of observations if we know the mean and standard deviation of a collection of normally distributed data: 68.2 percent of the sample results fall within a one SD range above and below the mean (+/- 1 SD), implying that 68 percent of the patients will weigh between 75 and 85 kg. Because +/- 2 SD encompasses 95.4 percent of the data, around 95 percent of the patients will weigh between 70 and 90 kg. +/- 3 SD encompasses 99.7% of the values, implying that nearly all of the patients will weigh between 65 and 95 kg.
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 6
Correct
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Question 7
Correct
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A 44 year old woman sustains an injury to the median nerve at the elbow after falling awkwardly. Which of the following clinical features are you LEAST likely to see on examination:
Your Answer: Loss of flexion of the medial two digits
Explanation:Flexion of the index and middle fingers at the IPJs is lost due to paralysis of the flexor digitorum superficialis and the lateral half of the flexor digitorum profundus. Flexion of the MCPJs of the index and middle fingers are lost due to paralysis of the lateral two lumbrical muscles. Flexion of the ring and little fingers are preserved as these are supported by the medial half of the flexor digitorum profundus and the medial two lumbrical muscles, innervated by the ulnar nerve.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 8
Incorrect
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Regarding the lung roots, which of the following statements is CORRECT:
Your Answer: Each lung root contains two pulmonary arteries and a pulmonary vein.
Correct Answer: Generally the pulmonary arteries lie superior to the pulmonary veins in the lung root.
Explanation:Each lung root contains a pulmonary artery, two pulmonary veins, a main bronchus, bronchial vessels, nerves and lymphatics. Generally the pulmonary artery is superior in the lung root, the pulmonary veins are inferior and the bronchi are somewhat posterior in position. The vagus nerves pass posterior to the lung roots while the phrenic nerves pass anterior to them.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 9
Correct
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Gallstones are commonly found lodged in which of the following parts of the gallbladder?
Your Answer: Neck
Explanation:There is a significant association between the presence of Hartmann’s pouch and gallbladder stones. It is the most common location for gallstones to become lodged and cause cholestasis.
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This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 10
Incorrect
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A patient presents to ED with heartburn for which they already take regular antacids. Which of the following drugs can be affected if taken with antacids:
Your Answer: Bendroflumethiazine
Correct Answer: Digoxin
Explanation:Antacids should preferably not be taken at the same time as other drugs since they may affect absorption. When antacids are taken with acidic drugs (e.g. digoxin, phenytoin, chlorpromazine, isoniazid) they cause the absorption of the acidic drugs to be decreased, which causes low blood concentrations of the drugs, which ultimately results in reduced effects of the drugs. Antacids taken with drugs such as pseudoephedrine and levodopa increase absorption of the drugs and can cause toxicity/adverse events due to increased blood levels of the drugs. Antacids that contain magnesium trisilicate and magnesium hydroxide when taken with some other medications (such as tetracycline) will bind to the drugs, and reduce their absorption and effects.
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This question is part of the following fields:
- Gastrointestinal
- Pharmacology
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Question 11
Correct
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Where is angiotensin I primarily converted to angiotensin II:
Your Answer: Lungs
Explanation:Angiotensin I is converted to angiotensin II by the removal of two C-terminal residues by the enzyme angiotensin-converting enzyme (ACE). This primarily occurs in the lungs, although it does also occur to a lesser degree in endothelial cells and renal epithelial cells.The main actions of angiotensin II are:Vasoconstriction of vascular smooth muscle (resulting in increased blood pressure)Vasoconstriction of the efferent arteriole of the glomerulus (resulting in an increased filtration fraction and preserved glomerular filtration rate)Stimulation of aldosterone release from the zona glomerulosa of the adrenal cortexStimulation of anti-diuretic hormone (vasopressin) release from the posterior pituitaryStimulation of thirst via the hypothalamusActs on the Na+/H+ exchanger in the proximal tubule of the kidney to stimulate Na+reabsorption and H+excretion
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This question is part of the following fields:
- Physiology
- Renal
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Question 12
Incorrect
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Which of the following statements is true about anterior cord syndrome?
Your Answer: There is preservation of temperature sensation
Correct Answer: There is preservation of proprioception
Explanation:Anterior cord syndrome is an incomplete cord syndrome that predominantly affects the anterior 2/3 of the spinal cord, characteristically resulting in motor paralysis below the level of the lesion as well as the loss of pain and temperature at and below the level of the lesion. The patient presentation typically includes these two findings; however, there is variability depending on the portion of the spinal cord affected. Other findings include back pain, or autonomic dysfunction such as hypotension, neurogenic bowel or bladder, and sexual dysfunction. The severity of motor dysfunction can vary, typically resulting in paraplegia or quadriplegia.Proprioception, vibratory sense, two-point discrimination, and fine touch are not affected in anterior cord syndrome. These sensations are under the control of the dorsal column of the spinal cord, which is supplied by two posterior spinal arteries running in the posterior lateral sulci.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 13
Incorrect
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All of the following statements are incorrect about insulin except:
Your Answer: The effects of insulin are mediated by a G-protein coupled receptor.
Correct Answer: Proinsulin is cleaved into insulin and C peptide.
Explanation:Proinsulin is synthesised as a single-chain peptide. A connecting peptide (C peptide) within storage granules is removed by proteases to yield insulin. Insulin:1. is a polypeptide hormone consisting of two short chains (A and B) linked by disulphide bonds. 2. is produced by beta cells, located centrally within the islets of Langerhans, in the endocrine tissues of the pancreas. 3. release is stimulated initially during eating by the parasympathetic nervous system and gut hormones such as secretin. However, most output is driven by the rise in plasma glucose concentration that occurs after a meal. 4. effects are mediated by the receptor tyrosine kinase.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 14
Correct
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When calculating the ventilation over perfusion ratio of a male patient, you should remember the ideal V/Q ratio for this patient to compare with his results. What is the approximate ventilation value for a healthy male patient?
Your Answer: 5 L/min
Explanation:The ventilation/perfusion ratio (V/Q ratio) is a ratio used to assess the efficiency and adequacy of the matching ventilation and perfusion. The ideal V/Q ratio is 1. In an average healthy male, the ventilation value is approximately 5 L/min and the perfusion value is approximately 5 L/min. Any mismatch between ventilation and perfusion will be evident in the V/Q ratio. If perfusion is normal but ventilation is reduced, the V/Q ratio will be less than 1, whereas if ventilation is normal but perfusion is reduced, the V/Q ratio will be greater than 1. If the alveoli were ventilated but not perfused at all, then the V/Q ratio would be infinity.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 15
Incorrect
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The following statements are not true of the flexor digiti minimi brevis, except?
Your Answer: It forms part of the thenar eminence
Correct Answer: It is situated on the radial border of abductor digiti minimi
Explanation:Flexor digiti minimi brevis muscle is located on the ulnar side of the palm, lying on the radial border of the abductor digiti minimi. Together with the abductor digiti minimi and opponens digiti minimi muscles, it forms the hypothenar eminence. The muscle is situated inferior and lateral to adductor digiti minimi muscle and superior and medial to opponens digiti minimi muscle. The proximal parts of flexor digiti minimi brevis and abductor digiti minimi muscles form a gap through which deep branches of the ulnar artery and ulnar nerve pass.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 16
Correct
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A 28-year-old female arrives after taking an unknown chemical in excess. She is tired and her speech is slurred. The following are her observations and results: HR 118, BP 92/58, SaO2 96%HR 118, 11/15  The following are the results of his arterial blood gas (ABG):pH: 7.24 pO 2 : 9.4 kPa PCO2 : 3.3 kPa HCO 3 -: 22 mmol/l Na + : 143 mmol/l Cl – : 99 mmol/l Lactate: 5 IU/lWhich of the following statements about this patient is TRUE?
Your Answer: Her anion gap is elevated
Explanation:The interpretation of arterial blood gas (ABG) aids in the measurement of a patient’s pulmonary gas exchange and acid-base balance. The normal values on an ABG vary a little depending on the analyser, but they are roughly as follows:Variable RangepH 7.35 – 7.45PaO2 10 – 14 kPaPaCO2 4.5 – 6 kPaHCO3- 22 – 26 mmol/lBase excess -2 – 2 mmol/lThe patient’s history indicates that she has taken an overdose in this case. Because her GCS is 11/15 and she can communicate with slurred speech, she is clearly managing her own airway, there is no current justification for intubation.The following are the relevant ABG findings:Hypoxia (mild)pH has been lowered (acidaemia)PCO2 levels are low.bicarbonate in its natural stateLactate levels have increasedThe anion gap represents the concentration of all the unmeasured anions in the plasma. It is the difference between the primary measured cations and the primary measured anions in the serum. It can be calculated using the following formula:Anion gap = [Na+] – [Cl-] – [HCO3-]The reference range varies depending on the technique of measurement, but it is usually between 8 and 16 mmol/L.The following formula can be used to compute her anion gap:Anion gap = [143] – [99] – [22]Anion gap = 22As a result, it is clear that she has a metabolic acidosis with an increased anion gap.The following are some of the causes of type A and type B lactic acidosis:Type A lactic acidosisType B lactic acidosisShock (including septic shock)Left ventricular failureSevere anaemiaAsphyxiaCardiac arrestCO poisoningRespiratory failureSevere asthma and COPDRegional hypoperfusionRenal failureLiver failureSepsis (non-hypoxic sepsis)Thiamine deficiencyAlcoholic ketoacidosisDiabetic ketoacidosisCyanide poisoningMethanol poisoningBiguanide poisoning
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 17
Incorrect
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You are treating a patient with a Clostridium difficile infection. His condition was found to be antibiotic-associated. Which of the following pieces of advice on preventing the spread of this disease should you give this patient?
Your Answer: Prophylactic treatment with metronidazole
Correct Answer: Washing hands with soap and water
Explanation:Clostridium difficile (C. diff) can cause colitis, or inflammation of the colon. To prevent its spread, one should practice good hand hygiene, regularly clean areas of the home that may become contaminated with C. difficile, practice good hand hygiene, and clean surfaces, spills, and accidents.
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This question is part of the following fields:
- Microbiology
- Principles
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Question 18
Incorrect
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Which of the following has the most potent glucocorticoid effect:
Your Answer: Hydrocortisone
Correct Answer: Dexamethasone
Explanation:Dexamethasone and betamethasone have the most potent glucocorticoid (anti-inflammatory) effect.
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This question is part of the following fields:
- Endocrine
- Pharmacology
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Question 19
Incorrect
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Regarding the tongue, which of the following statements is CORRECT:
Your Answer: The lingual tonsil is found on the underside of the tongue.
Correct Answer: The lymphatic supply of the tongue drains to the jugulo-omohyoid node of the deep cervical chain.
Explanation:All lymphatics from the tongue ultimately drain into the deep cervical chain of nodes along the internal jugular vein, particularly the jugulo-omohyoid lymph node.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 20
Incorrect
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Regarding antiemetics, which of the following statements is INCORRECT:
Your Answer: Prochlorperazine acts on the chemoreceptor trigger zone as a dopamine antagonist.
Correct Answer: Of the antiemetics, cyclizine is most commonly associated with acute dystonic reactions.
Explanation:Cyclizine acts by inhibiting histamine pathways and cholinergic pathways involved in transmission from the vestibular apparatus to the vomiting centre. Metoclopramide is a dopamine-receptor antagonist which acts both peripherally in the GI tract and centrally within the chemoreceptor trigger zone. Prochlorperazine is a dopamine-D2 receptor antagonist and acts centrally by blocking the chemoreceptor trigger zone. Metoclopramide and prochlorperazine are both commonly associated with extrapyramidal effects, such as acute dystonic reaction. Cyclizine may rarely cause extrapyramidal effects.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 21
Incorrect
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Which of the following describes the site of a Meckel's diverticulum:
Your Answer: Second part of duodenum
Correct Answer: Ileum
Explanation:Meckel’s lies on the antimesenteric surface of the middle-to-distal ileum, approximately 2 feet proximal to the ileocaecal junction. It appears as a blind-ended tubular outpouching of bowel, about 2 inches long, occurring in about 2% of the population, and may contain two types of ectopic tissue (gastric and pancreatic). The rich blood supply to the diverticulum is provided by the superior mesenteric artery.Proximal to the major duodenal papilla the duodenum is supplied by the gastroduodenal artery (branch of the coeliac trunk) and distal to the major duodenal papilla it is supplied by the inferior pancreaticoduodenal artery (branch of superior mesenteric artery). The arterial supply to the jejunoileum is from the superior mesenteric artery.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 22
Incorrect
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Regarding threadworms, which of the following statements is CORRECT:
Your Answer: Symptoms are usually of abdominal discomfort and a change in bowel habit.
Correct Answer: First line treatment of threadworms is with mebendazole.
Explanation:First line treatment of threadworms is with mebendazole, with treatment of the whole family, and a repeat treatment after 2 weeks. Threadworms live in the large bowel, but direct multiplication of worms does not occur here. Threadworms most commonly infect children, and may be symptomatic or cause pruritus ani.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 23
Correct
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Streptococcus pyogenes is commonly implicated in all of the following infective diseases EXCEPTÂ for:
Your Answer: Gas gangrene
Explanation:Gas gangrene is a life-threatening infection caused by toxin-producing Clostridium species, primarily Clostridium perfringens, and characterised by rapidly progressive muscle necrosis, gas production and sepsis.Gas gangrene is not a notifiable disease.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 24
Correct
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Which of the following statements about neutrophils is TRUE:
Your 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 25
Incorrect
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Approximately what proportion of lymphocytes are B-cells:
Your Answer: 0.65
Correct Answer: 0.2
Explanation:B-cells (20% of lymphocytes) mature in the bone marrow and circulate in the peripheral blood until they undergo recognition of antigen. B-cell immunoglobulin molecules synthesised in the cell are exported and bound to the surface membrane to become the B-cell receptor (BCR) which can recognise and bind to a specific antigen (either free or presented by APCs). The BCR is also important for antigen internalisation, processing and presentation to T helper cells. Most antibody responses require help from antigen-specific T helper cells (although some antigens such as polysaccharide can lead to T-cell independent B-cell antibody production). When the B-cell is activated, the receptor itself is secreted as free soluble immunoglobulin and the B-cell matures into a memory B-cell or a plasma cell (a B-cell in its high-rate immunoglobulin secreting state). Plasma cells are non-motile and are found predominantly in the bone marrow or spleen. Most plasma cells are short-lived (1 – 2 weeks) but some may survive much longer. A proportion of B-cells persist as memory cells, whose increased number and rapid response underlies the augmented secondary response of the adaptive immune system.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 26
Incorrect
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Regarding the extensor carpi ulnaris muscle, which of the following statements is true?
Your Answer: It arises from the medial epicondyle of the elbow
Correct Answer: It receives its blood supply from the ulnar artery
Explanation:Extensor carpi ulnaris is a fusiform muscle in the posterior forearm. It spans between the elbow and base of the little finger. This muscle belongs to the superficial forearm extensor group, along with anconaeus, brachioradialis, extensor carpi radialis longus, extensor carpi radialis brevis, extensor digitorum and extensor digiti minimi muscles.Like all the muscles of this compartment, extensor carpi ulnaris works as an extensor of the wrist. Moreover, due to its specific course, this muscle also acts to adduct the hand.Extensor carpi ulnaris is innervated by the posterior interosseous nerve (C7, C8), a branch of the deep division of the radial nerve. The radial nerve stems from the posterior cord of the brachial plexus.Blood supply to the extensor carpi ulnaris muscle is provided by branches of the radial recurrent and posterior interosseous arteries, which stem from the radial and ulnar arteries, respectively.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 27
Incorrect
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When a person changes from a supine to an upright position, which of the followingcompensatory mechanismsoccurs:
Your Answer: Decreased total peripheral resistance (TPR)
Correct Answer: Increased contractility
Explanation:On standing from a prone position, gravity causes blood to pool in veins in the legs. Central venous pressure (CVP) falls, causing a fall in stroke volume and cardiac output (due to Starling’s law) and thus a fall in blood pressure. Normally this fall in BP is rapidly corrected by the baroreceptor reflex which causes venoconstriction (partially restoring CVP), and an increase in heart rate and contractility, so restoring cardiac output and blood pressure. Impaired autonomic nervous activity in the elderly accounts for the greater likelihood of postural hypotension. Any symptoms of dizziness, blurred vision or syncope is due to a transient fall in cerebral perfusion that occurs before cardiac output and mean arterial pressure (MAP) can be corrected.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 28
Correct
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Dysuria and urinary frequency are symptoms of a 29-year-old woman. A urine dipstick is used to detect the presence of blood, protein, leucocytes, and nitrites in the urine. You diagnose a urinary tract infection and give antibiotics to the patient.In the United Kingdom, which of the following antibiotics has the highest percentage of E.coli resistance?
Your Answer: Trimethoprim
Explanation:In the United Kingdom, antibiotic resistance is becoming a significant factor in the treatment of urinary tract infections and pyelonephritis. E. coli (the main causative organism of both urinary tract infections and acute pyelonephritis) resistance to the following antibiotics in laboratory-processed urine specimens is:30.3 percent trimethoprim (varies by area from 27.1 to 33.4 percent )19.8 percent co-amoxiclav (varies by area from 10.8 to 30.7 percent )Ciprofloxacin (Cipro): 10.6% (varies by area from 7.8 to 13.7 percent )Cefalexin has a concentration of 9.9%. (varies by area from 8.1 to 11.4 percent )
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 29
Correct
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Regarding saliva, which of the following statements is CORRECT:
Your Answer: Saliva production is decreased by inhibition of the parasympathetic nervous system.
Explanation:At rest, saliva is predominantly produced by the submandibular gland (65%) but when stimulated, the parotid glands produce a higher proportion of the total saliva production (50%) than at rest. Saliva is alkaline and hypotonic to plasma. The predominant digestive enzymes in saliva are alpha-amylase and lingual lipase; lingual lipase is not functionally very important, but alpha-amylase is important for the initiation of starch digestion. Saliva production is decreased by inhibition of the parasympathetic nervous system e.g. by sleep, dehydration, anticholinergic drugs and fear.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 30
Incorrect
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A 32-year-old woman diagnosed with hyperthyroidism has her T 4 levels grossly elevated and she is started on carbimazole.A release of which of the following from the hypothalamus is inhibited by increase in T4 levels?
Your Answer:
Correct Answer: Thyrotropin-releasing hormone
Explanation:A negative feedback mechanism involving the hypothalamic-pituitary-thyroid axis controls the release of T3 and T4 into the bloodstream. When metabolic rate is low or serum T3 and/or T4 levels are decrease, this triggers the secretion of thyrotropin-releasing hormone (TRH) from the hypothalamus.TRH goes to the anterior pituitary gland and stimulates secretion of thyroid-stimulating hormone (TSH). An increased serum level of T3 and T4 inhibits the release of TRH.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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SESSION STATS - PERFORMANCE PER SPECIALTY
