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Question 1
Correct
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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: 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.
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 2
Incorrect
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Compression of this nerve can cause weakness in the left leg while walking and thigh adduction weakness at the hip joint.
Your Answer: 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 3
Incorrect
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Which of the following is NOT a feature characteristic of intravascular haemolysis:
Your Answer: Methaemalbuminaemia
Correct Answer: Bilirubinuria
Explanation:Features of intravascular haemolysis include:haemoglobinaemia, methaemalbuminaemia, haemoglobinuria (dark urine) and haemosiderinuria
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This question is part of the following fields:
- Haematology
- Pathology
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Question 4
Incorrect
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A 35-year-old woman has complaints of nausea, abdominal pain and dark urine. On examination, you notice she has jaundice. She tells you she recently started a new medication.Which drug is NOT likely to cause cholestatic jaundice out of the following?
Your Answer: Ibuprofen
Correct Answer: Isoniazid
Explanation:Isoniazid is an antibiotic used in the treatment of tuberculosis. It can cause acute, dose-dependent, hepatitis but is not a recognised cause of cholestatic jaundice.The drugs that cause cholestatic jaundice are the following:1. Nitrofurantoin2. Erythromycin3. Cephalosporins4. Verapamil5. NSAIDs6. ACE inhibitors7. Tricyclic antidepressants8. Phenytoin9. Azathioprine10. Carbamazepine11. Oral contraceptive pills12. Diazepam13. Ketoconazole14. Tamoxifen
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 5
Correct
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A 27-year-old man was sent to the emergency department by ambulance with suspected anaphylaxis. What is the best first-line treatment for this patient?
Your Answer: 500 micrograms of adrenaline intramuscularly
Explanation:Anaphylaxis is the sudden onset of systemic hypersensitivity due to IgE-mediated chemical release from mast cells and basophils. If anaphylaxis is suspected, 500 micrograms of adrenaline should be administered promptly (0.5 ml of 1:1000 solution). In anaphylaxis, the intramuscular route is the most immediate approach; the optimal site is the anterolateral aspect of the middle part of the thigh. Intravenous adrenaline should only be given by people who are well-versed in the use and titration of vasopressors in their routine clinical practice.
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 6
Correct
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When inserting a Seldinger chest drain for management of pneumothorax, the 'safe triangle' should be identified. Which of the following forms the inferior border of the 'safe triangle'?
Your Answer: 5 th intercostal space
Explanation:Care and management of the thoracostomy tubes (chest tubes) are subject to the direction and practice pattern of the responsible physician. Therefore, it is difficult to make a “one size fits all” set of instructions about the specific management recommendations for all chest tubes. It is recommended to discuss specific expectations for management with the patient’s attending physician. Facility specific Clinical Practice Guidelines (CPGs) may provide further guidance for one’s practice.Placement of the appropriately sized chest tube is performed on the affected side. The typical landmark for placement is the 4th or 5th intercostal space (nipple line for males, inframammary fold for females) at the anterior axillary line. The space above the 5th intercostal space and below the base of the axilla that is bordered posteriorly by the trapezius and anteriorly by the pectoralis muscle has recently been described as the safe triangle. Tubes are positioned anteriorly for pneumothoraces and posteriorly for fluid processes.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 7
Correct
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Which of the following statements is correct regarding homeostasis?
Your Answer: In negative feedback mechanisms, effectors always act to move the variable in the opposite direction to the change that was originally detected.
Explanation:The vast majority of systems within the body work by negative feedback mechanisms. This negative feedback refers to the way that effectors act to move the variable in the opposite direction to the change that was originally detected. Because there is an inherent time delay between detecting a change in a variable and effecting a response, the negative feedback mechanisms cause oscillations in the variable they control. There is a narrow range of values within which a normal physiological function occurs and this is called the ‘set point’. The release of oxytocin in childbirth is an example of positive feedback.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 8
Correct
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You review an 83-year-old woman who has stage 5 chronic kidney disease. She has a number of electrolyte problems.Which ONE of the following decreases the renal reabsorption of phosphate?
Your Answer: Parathyroid hormone
Explanation:Parathyroid hormone (PTH) is a polypeptide containing 84 amino acids. It is the principal controller of free calcium in the body.The main actions of parathyroid hormone are:Increases plasma calcium concentrationDecreases plasma phosphate concentrationIncreases osteoclastic activity (increasing calcium and phosphate resorption from bone)Increases renal tubular reabsorption of calciumDecreases renal phosphate reabsorptionIncreases renal conversion of 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol (via stimulation of 1-alpha hydroxylase)Increases calcium and phosphate absorption in the small intestine (indirectly via increased 1,25-dihydroxycholecalciferol)
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 9
Incorrect
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A 25 year old man has sustained a fracture to the surgical neck of the humerus after falling from his bike. Examination suggests an axillary nerve injury. The clinical features expected to be seen in this patient are:
Your Answer: Weakness of shoulder flexion
Correct Answer: Weakness of shoulder abduction
Explanation:Axillary nerve injury results in:1. weakness of arm abduction (paralysis of deltoid), 2. weakness of lateral rotation of the arm (paralysis of teres minor) 3. loss of sensation over the regimental badge area.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 10
Correct
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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 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 11
Incorrect
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A patient presents with a history of renal problems, generalised weakness and palpitations. Her serum potassium levels are measured and come back at 6.2 mmol/L. An ECG is performed, and it shows some changes that are consistent with hyperkalaemia.Which of the following ECG changes is usually the earliest sign of hyperkalaemia? Select ONE answer only.
Your Answer: Prolonged PR segment
Correct Answer: Peaked T waves
Explanation:Hyperkalaemia causes a rapid reduction in resting membrane potential leading to increased cardiac depolarisation and muscle excitability. This in turn results in ECG changes which can rapidly progress to ventricular fibrillation or asystole. Very distinctive ECG changes that progressively change as the K+level increases:K+>5.5 mmol/l – peaked T waves (usually earliest sign of hyperkalaemia), repolarisation abnormalitiesK+>6.5 mmol/l – P waves widen and flatten, PR segment lengthens, P waves eventually disappearK+>7.0 mmol/l – Prolonged QRS interval and bizarre QRS morphology, conduction blocks (bundle branch blocks, fascicular blocks), sinus bradycardia or slow AF, development of a sine wave appearance (a pre-terminal rhythm)K+>9.0 mmol/l – Cardiac arrest due to asystole, VF or PEA with a bizarre, wide complex rhythm.
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 12
Correct
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Which of the following is NOT a typical clinical feature of hypoglycaemia:
Your Answer: Polyuria
Explanation:Clinical features of hypoglycaemia: Autonomic symptoms: Sweating, feeling hot, anxiety/agitation, palpitations, shaking, paraesthesia, dizzinessNeuroglycopaenic symptoms: Weakness, blurred vision, difficulty speaking, poor concentration, poor coordination, drowsiness, confusion, seizures, comaOther symptoms: Nausea, fatigue, hunger
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 13
Correct
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Which of the following leukaemias is most common in children in the UK:
Your Answer: Acute lymphoblastic leukaemia
Explanation:Acute lymphoblastic leukaemia (ALL) is caused by an accumulation of lymphoblasts in the bone marrow and is the most common malignancy of childhood. The incidence of ALL is highest at 3 – 7 years, with 75% of cases occurring before the age of 6. There is a secondary rise after the age of 40 years. 85% of cases are of B-cell lineage and have an equal sex incidence; there is a male predominance for the 15% of T-cell lineage.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 14
Correct
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Blood flows from the left atrium into the left ventricle via:
Your Answer: The mitral valve
Explanation:Blood flows from the right atrium into the right ventricle via the tricuspid atrioventricular valve and from the left atrium into the left ventricle via the mitral atrioventricular valve. Blood is ejected from the right ventricle through the pulmonary semilunar valve into the pulmonary artery and from the left ventricle via the aortic semilunar valve into the aorta.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 15
Correct
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Which of the following is NOT a typical feature of benzodiazepine toxicity:
Your Answer: Hyperventilation
Explanation:Features of benzodiazepine toxicity include: drowsiness, ataxia, dysarthria, nystagmus, occasionally respiratory depression and coma
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 16
Incorrect
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Regarding the lacrimal apparatus, which of the following statements is CORRECT:
Your Answer: The nasolacrimal duct empties into the middle nasal meatus.
Correct Answer: Lacrimal fluid is drained from the eyeball through the lacrimal punctum.
Explanation:Lacrimal fluid is drained from the eyeball through the lacrimal punctum.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 17
Incorrect
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You are asked to review the blood results on a 56-year-old man who appears to be acutely unwell. His results show that he is neutropenic.Which ONE of the following is NOT a recognized cause of a neutropenia?
Your Answer: Viral infections
Correct Answer: Hyposplenism
Explanation:Neutropenia is defined as a total neutrophil count of < 2.0 x 109/l.It can be caused by:Viral infectionsCollagen disease e.g. SLE and RAChemotherapy and radiotherapyHypersplenismMarrow infiltrationVitamin and folate deficiencyDrug reactionsDrugs that cause neutropenia include flecainide, phenytoin, carbimazole, indomethacin and co-trimoxazole.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 18
Incorrect
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Many of the chemical digestion and absorption takes place in the small intestine. Most digestive enzymes in the small intestine are secreted by the pancreas and enter the small intestine through the pancreatic duct.Which of these digestive enzymes is responsible for breaking down carbohydrates into monosaccharides?
Your Answer: Pancreatic amylase
Correct Answer: Glucoamylase
Explanation:Majority of carbohydrates are broken down into monosaccharides (glucose, fructose galactose) and are absorbed by the small intestine. Enzymes released from the brush border break down carbohydrate. Some carbohydrates, such as cellulose, are not digested at all, despite being made of multiple glucose units. This is because the cellulose is made out of beta-glucose that makes the inter-monosaccharide bindings different from the ones present in starch, which consists of alpha-glucose. Humans lack the enzyme for splitting the beta-glucose-bond.The principal brush border enzymes are dextranase and glucoamylase. Other brush border enzymes are maltase, sucrase, and lactase.Pancreatic amylase breaks down some carbohydrates (notably starch) into oligosaccharides. Dextranase and glucoamylase, then further break down oligosaccharides.Trypsin aids in digestion of protein.Chymotrypsin is a proteolytic enzyme that digests proteinCarboxypeptidase hydrolyses the first peptide or amide bond at the carboxyl or C-terminal end of proteins and peptides
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This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 19
Incorrect
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Following a decrease in extracellular volume, which of the following is a reaction to enhanced sympathetic innervation of the kidney:
Your Answer: Renal arteriole vasodilation
Correct Answer: Release of renin
Explanation:The RAS pathway begins with renin cleaving its substrate, angiotensinogen (AGT), to produce the inactive peptide, angiotensin I, which is then converted to angiotensin II by endothelial angiotensin-converting enzyme (ACE). ACE activation of angiotensin II occurs most extensively in the lung. Angiotensin II mediates vasoconstriction as well as aldosterone release from the adrenal gland, resulting in sodium retention and increased blood pressure.
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This question is part of the following fields:
- Physiology
- Renal
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Question 20
Correct
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Regarding the power of a study, which of the following statements is INCORRECT:
Your Answer: The power of a study is not affected by data variability.
Explanation:A study should only be undertaken if the power is at least 80%; a study power set at 80% accepts a likelihood of 1 in 5 (20%) of missing a statistically significant difference where one exists.The determinants of power are:the sample size (the power increases with sample size)the variability of the observations (the power increases as the variability decreases)the effect size of interest (the power is greater for a larger expected effect size)and the significance level, α (the power is greater if the significance level is larger); therefore the probability of a type I error increases as the probability of a type II error decreases.
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 21
Correct
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A 50-year-old man presents with headaches, lethargy, hypertension, and electrolyte disturbance. A diagnosis of primary hyperaldosteronism is made.Which biochemical pictures would best support this diagnosis?
Your Answer: Hypokalaemic metabolic alkalosis
Explanation:When there are excessive levels of aldosterone outside of the renin-angiotensin axis, primary hyperaldosteronism occurs. High renin levels will lead to secondary hyperaldosteronism. The classical presentation of hyperaldosteronism when symptoms are present include:HypokalaemiaMetabolic alkalosisHypertensionNormal or slightly raised sodium levels
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 22
Correct
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In a ward round, you come across a patient's treatment chart prescribed an antibiotic to fight his infection. This antibiotic is a protein synthesis inhibitor.Which of the following antimicrobial drugs is prescribed to this patient?
Your Answer: Gentamicin
Explanation:Gentamicin, an aminoglycoside antibiotic, acts by binding to the 30S subunit of the bacterial ribosome inhibiting the binding of aminoacyl-tRNA and thus preventing initiation of protein synthesis.Vancomycin inhibits cell wall peptidoglycan formation by binding the D-Ala-D-Ala portion of cell wall precursors. Penicillins and cephalosporins are the major antibiotics that inhibit bacterial cell wall synthesis. They inactivate transpeptidases that help cross-link peptidoglycans in cell walls. Metronidazole and the other 5-nitroimidazole agents inhibit nucleic acid synthesis by forming toxic free radical metabolites in the bacterial cell that damage DNA. Ciprofloxacin inhibits prokaryotic enzymes topoisomerase II (DNA gyrase) and topoisomerase IV.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 23
Incorrect
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Which of the following infections is vancomycin most likely prescribed for?
Your Answer: Meningococcal meningitis
Correct Answer: Clostridium difficile colitis
Explanation:125 mg PO q6hr for 10 days is indicated for treatment of Clostridium difficile (C. difficile)-associated diarrhoea
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 24
Correct
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Which of the following is NOT a typical cerebellar sign:
Your Answer: Hypertonia
Explanation:Hypotonia means decreased muscle tone. It can be a condition on its own, called benign congenital hypotonia, or it can be indicative of another problem where there is progressive loss of muscle tone, such as muscular dystrophy or cerebral palsy. It is usually detected during infancy. Hypotonia is characteristic of cerebellar dysfunction.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 25
Incorrect
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Cardiac muscle and skeletal muscle are alike, but there are a few key variations. Which of the following is NOT a characteristic of skeletal muscle but is a characteristic of cardiac muscle?
Your Answer: Contraction by excitation-contraction coupling
Correct Answer: The presence of intercalated discs
Explanation:Cardiac muscle is striated, and the sarcomere is the contractile unit, similar to skeletal muscle. Contracture is mediated by the interaction of calcium, troponins, and myofilaments, much as it occurs in skeletal muscle. Cardiac muscle, on the other hand, differs from skeletal muscle in a number of ways.In contrast to skeletal muscle cells, cardiac myocytes have a nucleus in the middle of the cell and sometimes two nuclei. The cells are striated because the thick and thin filaments are arranged in an orderly fashion, although the arrangement is less well-organized than in skeletal muscle.Intercalated discs, which work similarly to the Z band in skeletal muscle in defining where one cardiac muscle cell joins the next, are a very significant component of cardiac muscle.Adherens junctions and desmosomes, which are specialized structures that hold the cardiac myocytes together, are formed by the transverse sections. The lateral sections produce gap junctions, which join the cytoplasm of two cells directly, allowing for rapid action potential conduction. These critical properties allow the heart to contract in a coordinated manner, allowing for more efficient blood pumping.Cardiac myocytes have the ability to create their own action potentials, which is referred to as myogenic’. They can depolarize spontaneously to initiate a cardiac action potential. Pacemaker cells, as well as the sino-atrial (SA) and atrioventricular (AV) nodes, control this.The Purkinje cells and the cells of the bundle of His are likewise capable of spontaneous depolarization. While the bundle of His is made up of specialized myocytes, it’s vital to remember that Purkinje cells are not myocytes and have distinct characteristics. They are larger than myocytes, with fewer filaments and more gap junctions than myocytes. They conduct action potentials more quickly, allowing the ventricles to contract synchronously.Cardiac myocytes contract by excitation-contraction coupling, just like skeletal myocytes. Heart myocytes, on the other hand, utilise a calcium-induced calcium release mechanism that is unique to cardiac muscle (CICR). The influx of calcium ions (Ca2+) into the cell causes a ‘calcium spark,’ which causes more ions to be released into the cytoplasm.An influx of sodium ions induces an initial depolarisation, much as it does in skeletal muscle; however, in cardiac muscle, the inflow of Ca2+ sustains the depolarisation, allowing it to remain longer. Due to potassium ion (K+) inflow, CICR causes a plateau phase in which the cells remain depolarized for a short time before repolarizing. Skeletal muscle, on the other hand, repolarizes almost instantly.Comparison of skeletal and cardiac muscle:Skeletal muscle Cardiac muscleStriation Striated but arrangement less organised Multiple nuclei located peripherally Usually single nucleus (but can be two), located centrallyDiscs None Intercalated discsNo Gap junctions Gap junctions No Pacemaker PacemakerElectrical stimulation: Nervous system (excitation) Pacemaker (excitation)
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 26
Incorrect
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Which of the following muscles is least likely to be involved in forceful expiration:
Your Answer: Internal intercostal muscles
Correct Answer: External intercostal muscles
Explanation:Forceful expiration is primarily produced by the deeper thoracic muscles (internal and innermost intercostal muscles, subcostals and transversus thoracis) aided by contraction of the abdominal wall muscles which increase intra-abdominal pressure thus further reducing the volume of the thorax.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 27
Correct
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Pancreatic ductal alkaline fluid secretion is mainly stimulated by which of the following hormones:
Your Answer: Secretin
Explanation:Pancreatic exocrine secretion is controlled by:Parasympathetic stimulation which enhances secretion of both the enzyme and aqueous componentsSympathetic stimulation which inhibits pancreatic secretionSecretin which stimulates secretion of the alkaline-rich fluid from ductal cellsCholecystokinin which stimulates secretion of the enzyme-rich fluid from acinar cellsSomatostatin which inhibits secretion from both acinar and ductal cellsGastrin which stimulates pancreatic acinar cells to secrete digestive enzymes
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 28
Incorrect
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Regarding cross-sectional studies, which of the following statements is CORRECT:
Your Answer: They are particularly suitable for estimating incidence of a disease.
Correct Answer: They are particularly suitable for estimating point prevalence.
Explanation:Cross-sectional studies aim to provide data about population health, normal ranges of biological parameters, and disease prevalence or severity by observing the entire population, or a representative subset, at a single point in time. Cross-sectional studies are relatively simple and quick to perform and can be used to study multiple outcomes, but are subject to confounding and recall bias and are not suitable for studying rare diseases. Cross-sectional studies cannot be used to assess causation or to consider trends over time.
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This question is part of the following fields:
- Evidence Based Medicine
- Study Methodology
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Question 29
Incorrect
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C5 - C9 deficiency increases susceptibility to infection with which of the following:
Your Answer: Encapsulated bacteria
Correct Answer: Neisseria spp.
Explanation:If the complement sequence is completed, an active phospholipase (the membrane attack complex, MAC) is produced, which punches holes in the cell membrane and causes cell lysis. Because the MAC appears to be the sole means to destroy the Neisseria family of bacteria, C5 – C9 deficiency increases susceptibility to Neisseria infections.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 30
Correct
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You've been requested to give a discussion to a group of medical students about cardiovascular physiology. One of them inquires about cardiac output and asks if you can explain it.Which of the following statements is correct?
Your Answer: An average resting cardiac output in a woman is 5 L/min
Explanation:The terminology cardiac output refers to the amount of blood pumped by the heart in one minute. Women’s rates are around 5 L/min, whereas men’s rates are somewhat higher, around 5.5 L/min.Cardiac output (CO) is calculated by multiplying stroke volume (SV) by heart rate (HR):CO = HR x SVAs a result, both stroke volume and heart rate are exactly proportional to cardiac output. There will be an increase in cardiac output if the stroke volume or heart rate increases, and a reduction in cardiac output if the stroke volume or heart rate lowers.
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This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
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SESSION STATS - PERFORMANCE PER SPECIALTY
