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Question 1
Incorrect
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Regarding bicarbonate handling by the proximal tubule, which of the following statements is CORRECT:
Your Answer: HCO 3 - is reabsorbed across the luminal membrane in exchange for H + ions by the HCO 3 -/H + antiporter.
Correct Answer: For each H + secreted into the lumen, one Na + and one HCO 3 - is reabsorbed into the plasma.
Explanation:About 80% of bicarbonate is reabsorbed in the proximal tubule. HCO3-is not transported directly, tubular HCO3-associates with H+secreted by epithelial Na+/H+antiporters to form carbonic acid (H2CO3) which readily dissociates to form carbon dioxide and water in the presence of carbonic anhydrase. CO2and water diffuse into the tubular cells, where they recombine to form carbonic acid which dissociates to H+and HCO3-. This HCO3-is transported into the interstitium largely by Na+/HCO3-symporters on the basolateral membrane (and H+is secreted back into the lumen). 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.
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This question is part of the following fields:
- Physiology
- Renal
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Question 2
Incorrect
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In the Paediatric Emergency Department, you saw a 6-year-old girl with severe bilateral conjunctivitis. You give her mother some general eye hygiene advice and prescribe chloramphenicol eye drops.What is the chloramphenicol's mechanism of action?
Your Answer: Disruption of cell membrane function
Correct Answer: Inhibition of protein synthesis
Explanation:Chloramphenicol is a broad-spectrum antibiotic that inhibits bacterial protein synthesis by blocking the 50S subunit of the bacterial ribosome’s peptidyl transferase activity. When administered systemically, it has limited usage due to the potential of significant side effects such as aplastic anaemia, peripheral neuropathy, and optic neuritis. It’s only used to treat typhoid fever and Haemophilus influenzae meningitis, but it’s usually better to use a broad-spectrum cephalosporin.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 3
Correct
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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: 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 4
Incorrect
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A 39-year-old woman is feeling unwell one week after a parathyroid surgery.Which of the following stimulates release of parathyroid hormone (PTH)?
Your Answer: Increased plasma calcium concentration
Correct Answer: Increased plasma phosphate concentration
Explanation:PTH is synthesised and released from the chief cells of the four parathyroid glands located behind the thyroid gland.It is a polypeptide containing 84 amino acids and it controls free calcium in the body.The following stimuli causes release of PTH:Increased plasma phosphate concentrationDecreased plasma calcium concentrationPTH release is inhibited by:Normal or increased plasma calcium concentrationHypomagnesaemiaThe main actions of PTH 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 5
Correct
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Which of the following microbes is spread by a vector:
Your Answer: Plasmodium falciparum
Explanation:The female Anopheles mosquito is the vector for Plasmodium falciparum transmission. Treponema pallidum is transmitted through sexual transmission or direct skin contact. Clostridium perfringens is spread by direct skin contact or through oral-faecal route. The oral-faecal pathway is how Vibrio cholerae spreads. Mycoplasma tuberculosis is spread via the airborne route.
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This question is part of the following fields:
- Microbiology
- Principles
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Question 6
Correct
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The pathophysiology of Addison's disease is as follows:
Your Answer: Adrenocortical insufficiency
Explanation:Primary adrenal insufficiency, also known as Addison’s disease, occurs when the adrenal glands cannot produce an adequate amount of hormones despite a normal or increased corticotropin (ACTH) level.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 7
Incorrect
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Regarding T helper cells, which of the following statements is CORRECT:
Your Answer: They are CD8 receptor positive.
Correct Answer: They form the vast majority (about 75%) of the total circulating T-cell population.
Explanation:CD4+ T-cells (Helper T cells)Recognise antigen only in association with HLA class II molecules (found on antigen presenting cells (APCs) e.g. dendritic cells, B-cells; present exogenous antigens that have been phagocytosed/endocytosed into intracellular vesicles)Form most of the circulating T-cell population (about 75%)Secrete cytokines (e.g. IFN-gamma) which are required for recruitment and activation of other immune cells such as macrophages, T cytotoxic cells and NK cells and for the activation of and production of immunoglobulin from B-cells
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 8
Incorrect
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Which of the following factors decreases insulin secretion:
Your Answer: Glucagon
Correct Answer: Catecholamines
Explanation:Factors that increase insulin secretion:↑ Blood glucose↑ Amino acids↑ Fatty acidsGlucagonSecretinAcetylcholineFactors that decrease insulin secretion:↓ Blood glucoseSomatostatinCatecholamines
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 9
Incorrect
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Bendoflumethiazide may cause all of the following electrolyte imbalances EXCEPT for:
Your Answer: Hyponatraemia
Correct Answer: Hypocalcaemia
Explanation:Common side effects of thiazide diuretics include:Excessive diuresis, postural hypotension, dehydration, renal impairmentAcid-base and electrolyte imbalanceHypokalaemia, hyponatraemia, hypomagnesaemia, hypercalcaemia, hypochloraemic alkalosisMetabolic imbalanceHyperuricaemia and goutImpaired glucose tolerance and hyperglycaemiaAltered plasma-lipid concentrationsMild gastrointestinal disturbances
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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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In all of the following conditions, lymphocytosis typically occurs except for:
Your Answer: Corticosteroid therapy
Explanation:In infants and young children, lymphocytosis often occurs in response to infections that would normally produce a neutrophil reaction in adults.Lymphocytosis occurs in:1. Viral infections (e.g. infectious mononucleosis, HIV, rubella, mumps, viral hepatitis, cytomegalovirus, herpes simplex or zoster)2. Bacterial infections (e.g. pertussis, tuberculosis, toxoplasmosis, syphilis)3. Chronic lymphoid leukaemias4. Acute lymphoblastic leukaemias5. Non-Hodgkin lymphoma6. Thyrotoxicosis
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 11
Correct
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During anaerobic respiration, what is the net generation of ATP molecules:
Your Answer: 2
Explanation:In anaerobic respiration, two ATP molecules are produced for every glucose molecule, as opposed to the 38 molecules of ATP produced in aerobic respiration.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 12
Incorrect
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Regarding hypernatraemia, which of the following statements is INCORRECT:
Your Answer: Diabetes insipidus causes hypernatraemia secondary to a pure water deficit.
Correct Answer: In acute severe hypernatraemia, seizures and intracranial vascular haemorrhage can occur as a result of brain cell lysis.
Explanation:Acute severe hypernatraemia is a medical emergency and requires inpatient management in a high dependency setting. Seizures and intracranial vascular haemorrhage as a result of brain cell crenation can occur. The cause is most commonly excessive water loss and the key aspect of treatment is aggressive fluid replacement (typically with normal saline as this is relatively hypotonic). If urine osmolality is low, diabetes insipidus (DI )should be considered and a trial of synthetic ADH given. In patients with known DI, it is essential to ensure synthetic ADH is given parenterally and that close fluid balance is observed.
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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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Regarding ampicillin, which of the following statements is CORRECT:
Your Answer: Ampicillin may cause a widespread maculopapular rash in a patient with glandular fever.
Explanation:Ampicillin is a broad-spectrum antibiotic, active against certain Gram-positive and Gram-negative organisms but is inactivated by penicillinases (similar to amoxicillin in spectrum). Ampicillin is associated with high levels of resistance, therefore it is often not appropriate for blind treatment of infection. It is principally indicated for the treatment of exacerbations of chronic bronchitis and middle ear infections, both of which may be due to Streptococcus pneumoniae and H. influenzae, and for urinary tract infections. Maculopapular rashes commonly occur with ampicillin (and amoxicillin) but are not usually related to true penicillin allergy. They almost always occur in patients with glandular fever; thus broad-spectrum penicillins should not be used for blind treatment of a sore throat. The risk of rash is also increased in patients with acute or chronic lymphocytic leukaemia or in cytomegalovirus infection.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 14
Correct
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Which of the following statements is correct regarding paracetamol?
Your Answer: Liver damage peaks 3 to 4 days after paracetamol ingestion.
Explanation:The maximum daily dose of paracetamol in an adult is 4 grams. Doses greater than this can lead to hepatotoxicity and, less frequently, acute kidney injury. Early symptoms of paracetamol toxicity include nausea, vomiting, and abdominal pain, and usually settle within 24 hours. Symptoms of liver damage include right subcostal pain and tenderness, and this peaks 3 to 4 days after paracetamol ingestion. Other signs of hepatic toxicity include encephalopathy, bleeding, hypoglycaemia, and cerebral oedema.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 15
Correct
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You've been summoned to a young man in the resus area who has an SVT. You decide to use adenosine after trying several vagal manoeuvres without success.The use of adenosine is not contraindicated in which of the following situations?
Your Answer: Concurrent use of a beta-blocker
Explanation:The use of a beta-blocker at the same time increases the risk of myocardial depression, but it is not a contraindication.The use of adenosine is contraindicated in the following situations:AsthmaCOPD (chronic obstructive pulmonary disease)Decompensated heart failure Long QT syndromeAV block in the second or third degreeSinusitis is a condition in which the sinuses become (unless pacemaker fitted)Hypotension that is severe
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 16
Correct
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Which of the following is a well recognised adverse effect of prochlorperazine:
Your Answer: Acute dystonic reaction
Explanation:Adverse actions include anticholinergic effects such as drowsiness, dry mouth, and blurred vision, extrapyramidal effects, and postural hypotension. Phenothiazines can all induce acute dystonic reactions such as facial and skeletal muscle spasms and oculogyric crises; children (especially girls, young women, and those under 10 kg) are particularly susceptible.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 17
Incorrect
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Regarding bronchiolitis, which of the following statements is CORRECT:
Your Answer: Antiviral treatment is given first line.
Correct Answer: Chest x-ray may show hyperinflation and increased peribronchial markings.
Explanation:Acute bronchiolitis is caused most commonly by respiratory syncytial virus, occurring mostly in children aged 6 months to 2 years. Children with bronchiolitis are febrile and tachypnoeic with a dry cough and difficulty feeding. Examination may reveal chest hyperinflation, respiratory distress, wheezing and fine end-inspiratory crepitations. Chest x-ray may show hyperinflation and increased peribronchial markings (although CXR should only performed if there is diagnostic uncertainty or an atypical course). Treatment is usually supportive, aerosolized ribavirin is reserved for severely ill or immunocompromised patients.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 18
Incorrect
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A 43 year old lady suffering with idiopathic thrombocytopenic purpura has a splenectomy. She is advised to get the Pneumococcal vaccine booster every 5 - 10 years as Streptococcus pneumoniae has which of the following properties that make her prone to infection to this organism?
Your Answer: It is alpha-haemolytic
Correct Answer: It is encapsulated
Explanation:There is a lifelong susceptibility to increased risk of infection from a variety of organisms in patients with hyposplenism, especially in children under 5 years and those with sickle cell anaemia. Patients are most susceptible is to the encapsulated bacteria Streptococcus pneumoniae, Haemophilus influenzae type B and Neisseria meningitidis. Streptococcus pneumoniae is particular concerning as it can cause rapid and fulminant disease, which can be fatal. Malaria and animal bites that become infected also tend to be more severe.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 19
Correct
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Bordetella pertussis is spread via which of the following routes:
Your Answer: Respiratory droplet route
Explanation:Bordetella pertussis is a Gram negative coccobacillus that causes whooping cough. B. pertussis is spread via the respiratory droplet route and expresses fimbriae that aid their adhesion to the ciliated epithelium of the upper respiratory tract, and produce a number of exotoxins, causing the characteristic thickened bronchial secretions, paralysis of cilia and lymphocytosis.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 20
Correct
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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 21
Incorrect
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Which of the following conditions require IV Lidocaine administration?
Your Answer: Bradyarrhythmias associated with adverse features
Correct Answer: Refractory ventricular fibrillation in cardiac arrest
Explanation:IV Lidocaine is indicated in Ventricular Arrhythmias or Pulseless Ventricular Tachycardia (after defibrillation, attempted CPR, and vasopressor administration)
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 22
Correct
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Which of the following side effects would you least associated with ciprofloxacin:
Your Answer: Folate deficiency
Explanation:Common side effects include diarrhoea, dizziness, headache, nausea and vomiting.Other adverse effects include: Tendon damage (including rupture), Seizures (in patients with and without epilepsy), QT-interval prolongation, Photosensitivity and Antibiotic-associated colitis
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 23
Correct
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A mother has serious concerns about vaccinating her child. She has read about many contraindications and risks in the papers and would like to discuss them with you.One of these is a valid contraindication to vaccination.
Your Answer: None of the other options
Explanation:The options listed in this question are not true contraindications to vaccination. Therefore, the correct answer is ‘none of the other options’.The contraindications to vaccination are:Confirmed anaphylactic reaction to a previous dose of the vaccine or a vaccine containing the same antigens.A confirmed anaphylactic reaction to another component in the vaccine.
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 24
Correct
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A patient suffers an injury to the nerve that innervates piriformis.The piriformis muscle is innervated by which of the following nerves? Select ONE answer only.
Your Answer: Nerve to piriformis
Explanation:Piriformis is innervated by the nerve to piriformis, which is a direct branch from the sacral plexus (S1 and S2).
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 25
Incorrect
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Regarding fluid balance, which of the following statements is CORRECT:
Your Answer: Osmosis is the passive movement of water from regions of high solute concentration to regions of low solute concentration.
Correct Answer: About three-quarters of extracellular fluid is interstitial.
Explanation:An ‘average’ person (70 kg male) contains about 40 litres of water in total, separated into different fluid compartments by biological semipermeable membranes; plasma cell membranes between extracellular and intracellular fluid, and capillary walls between interstitial and intravascular fluid. Around two-thirds of the total fluid (27 L) is intracellular fluid (ICF) and one-third of this (13 L) is extracellular fluid (ECF). The ECF can be further divided into intravascular fluid (3.5 L) and interstitial fluid (9.5 L). Transcellular fluid refers to any fluid that does not contribute to any of the main compartments but which are derived from them e.g. gastrointestinal secretions and cerebrospinal fluid, and has a collective volume of approximately 2 L.Osmosis is the passive movement of water across a semipermeable membrane from regions of low solute concentration to those of higher solute concentration.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 26
Correct
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For an action potential to occur, which of the following must be true:
Your Answer: Depolarisation of the membrane must reach threshold potential
Explanation:For an action potential to occur, the membrane must become more permeable to Na+and the Na+influx must be greater than the K+efflux. An action potential occurs when depolarisation of the membrane reaches threshold potential. The membrane must be out of the absolute refractory period, however an action potential can still occur in a relative refractory period but only in response to a larger than normal stimulus.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 27
Incorrect
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Which of the following factors does NOT decrease glucagon secretion:
Your Answer: Insulin
Correct Answer: Catecholamines
Explanation:Factors that increase glucagon secretion:↓ Blood glucose↑ Amino acidsCholecystokininCatecholaminesAcetylcholineFactors that decrease glucagon secretion:↑ Blood glucoseInsulinSomatostatinFatty acids, ketoacids
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 28
Correct
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A 62-year-old woman is brought to the Emergency Department as she is acutely unwell. Her attendants inform you that she was recently started on lithium as a mood stabilizer. You instantly send a blood sample to check for lithium levels. What is the usual therapeutic range for lithium?
Your Answer: 0.4-0.8 mmol/l
Explanation:Lithium is the drug of choice for recurrent bipolar illness but should be carefully monitored as it has a very low therapeutic index. The normal therapeutic range is 0.4-0.8 mmol/l. The lower end of the range is usually the target for the elderly and as maintenance therapy. Toxicity is usually seen at levels >1.5 mmol/l. Samples should be taken 12 hours after the dose, and levels should be checked one week after starting therapy and one week after every change in dosage.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 29
Incorrect
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A 33 year old female patient presents to emergency room with some symptoms that she thinks might be due to a drug that she has recently started. She was started on hyoscine butyl bromide for symptomatic relief of irritable bowel syndrome. The least likely expected side effect of this drug in this patient is:
Your Answer: Blurred vision
Correct Answer: Diarrhoea
Explanation:One of the commonest antispasmodic medications that is used is hyoscine butylbromide. It is an antimuscarinic and typical side effects of this class of drugs include:- dilation of pupils with loss of accommodation (cycloplegia) -photophobia resulting in blurred vision (Blind as a bat) -dry mouth, eyes and skin (Dry as a bone), -elevated temperature (Hot as a hare)-skin flushing (Red as a beet)-confusion or agitation particularly in the elderly (Mad as a hatter)-reduced bronchial secretions-transient bradycardia followed by tachycardia, palpitation and arrhythmias-urinary retention and/or constipation
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This question is part of the following fields:
- Gastrointestinal
- Pharmacology
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Question 30
Incorrect
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Which of the following is NOT an effect of cytokine activity:
Your Answer: Increased antibody production
Correct Answer: Opsonisation of bacteria for phagocytosis
Explanation:Cytokines are a family of chemical messengers, secreted by leucocytes, that act over short distances by binding specific receptors on target cell surfaces. They include: interleukins (act between leucocytes), interferons (inhibit replication of viruses within cells and activate macrophages and natural killer cells), growth factors, and tumour necrosis factors (kill tumour cells). Effects include: induction of fever and acute phase response, stimulation of leucocyte differentiation and maturation, leucocyte recruitment and activation and increased antibody production.
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This question is part of the following fields:
- Inflammatory Responses
- Pathology
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SESSION STATS - PERFORMANCE PER SPECIALTY
