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Question 1
Incorrect
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A patient with a high potassium level is at risk of going into cardiac arrest. What changes in the ECG may indicate the incident of cardiac arrest in this patient?
Your Answer: Prolonged QT interval
Correct Answer: Peaked T waves and broad QRS complex
Explanation:Severe hyperkalaemia can result in a heart attack or a life-threatening arrhythmia. T waves become narrow-based, pointed, and tall if hyperkalaemia is not treated. The QRS complex widens and eventually merges with the T wave, resulting in a classic sine-wave electrocardiogram. Ventricular fibrillation and asystole are likely to follow.
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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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A blood transfusion is given to a 52-year-old woman. She develops chills and rigours shortly after the transfusion begins. The following are her observations: Temperature 40°C, HR 116 bpm, BP 80/48, SaO 2 97 percent on air.Which of the following treatments is the most appropriate?
Your Answer: Slow the transfusion rate and administer diuretics
Correct Answer: Stop the transfusion and administer antibiotics
Explanation:Bacterial infections are common in the following situations:Platelet transfusions are associated with a higher risk of bacterial infection (as platelets are stored at room temperature)Immersion in a water bath thawed previously frozen components.Components of red blood cells that have been stored for several weeksGram-positive and Gram-negative bacteria have both been linked to transfusion-transmitted bacterial infection, but Gram-negative bacteria are linked to a higher rate of morbidity and mortality.Yersinia enterocolitica is the most common bacterial organism linked to transfusion-transmitted bacterial infection. This organism can multiply at low temperatures while also utilising iron as a nutrient. As a result, it’s well-suited to proliferating in blood banks.The following are some of the most common clinical signs and symptoms of a bacterial infection transmitted through a blood transfusion. These symptoms usually appear shortly after the transfusion begins:Fever is very high.Rigours and chillsVomiting and nauseaTachycardiaHypotensionCollapse of the circulatory systemIf a bacterial infection from a transfusion is suspected, the transfusion should be stopped right away. Blood cultures and a Gram stain should be requested, as well as broad-spectrum antibiotics. In addition, the blood pack should be returned to the blood bank for an urgent culture and Gram-stain.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 3
Incorrect
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A diagnosis of acute osteomyelitis was made on a patient with a known history of sickle cell disease. He has no joint prosthesis on in-dwelling metal work and no known drug allergies.Which of the following is most likely the causative agent of the case presented above?
Your Answer: Group B streptococcus
Correct Answer: Salmonella spp .
Explanation:Patients with sickle cell disease are prone to infection of the bone and bone marrow in areas of infarction and necrosis. Although Staphylococcus aureus is the most common cause of osteomyelitis in the general population, studies have shown that in patients with sickle cell disease, the relative incidence of Salmonella osteomyelitis is twice that of staphylococcal infection.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 4
Incorrect
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Thyroid cancer has spread to the regional lymph nodes of a patient as seen in a staging CT scan. The lymph from the thyroid gland will drain directly to which of the following nodes?
Your Answer: Submandibular lymph nodes
Correct Answer: Deep lateral cervical lymph nodes
Explanation:Lymphatic drainage of the thyroid gland involves the lower deep cervical, prelaryngeal, pretracheal, and paratracheal nodes. The paratracheal and lower deep cervical nodes, specifically, receive lymphatic drainage from the isthmus and the inferior lateral lobes. The superior portions of the thyroid gland drain into the superior pretracheal and cervical nodes.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 5
Incorrect
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In adults, the conus medullaris of the spinal cord lies at which of the following vertebral levels:
Your Answer: L3/L4
Correct Answer: L1/L2
Explanation:At birth, the conus medullaris lies at L3. By the age of 21, it sits at L1/L2.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 6
Incorrect
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A 30-year-old carpenter presented to the emergency room with a laceration of his upper volar forearm. Upon further exploration and observation, it was revealed that the nerve that innervates the pronator teres muscle has been damaged. Which of the following nerves is most likely damaged in the case?
Your Answer: The ulnar nerve
Correct Answer: The median nerve
Explanation:Pronator teres syndrome (PTS) is caused by a compression of the median nerve (MN) by the pronator teres (PT) muscle in the forearm. The median nerve, C6 and C7, innervates the pronator teres.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 7
Incorrect
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When the pulmonary artery is completely blocked, what is the ventilation over perfusion ratio for the area that it supplies?
Your Answer: 0.5
Correct Answer: Infinity
Explanation:The ventilation/perfusion ratio (V/Q ratio) is a ratio used to assess the efficiency and adequacy of the matching ventilation and perfusion. A pulmonary artery carries deoxygenated blood from the right side of the heart to the lungs. When a large pulmonary embolus completed blocked a pulmonary artery 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 8
Incorrect
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Regarding Helicobacter pylori, which of the following statements is INCORRECT:
Your Answer: It is Gram-negative.
Correct Answer: It is found as part of normal colonic flora.
Explanation:Helicobacter pyloriis a Gram-negative, helix shaped (curved rod), microaerophilic bacterium. It typically has 4-6 lophotrichous flagellae and is therefore highly motile. It has an outer membrane consisting of phospholipids and lipopolysaccharide.Helicobacter pyloriIs found in the upper gastrointestinal tract of approximately 50% of the population.Colonization withHelicobacter pyloriconfers a 10-20% lifetime risk of developing peptic ulcers and a 1-2% lifetime risk of developing gastric cancer.There is a strong association between mucosa-associated lymphoid tissue (MALT) lymphoma andHelicobacter pyloricolonization.The most reliable method for testing for colonization withHelicobacter pyloriis by biopsy during endoscopy and histological examination.Typically eradication requires a 14-day course of triple therapy with amoxicillin, clarithromycin and a proton pump inhibitor. Metronidazole is also often used as an alternative antibiotic in a triple therapy regime.Serum antibody levels fall slowly and therefore cannot be used to accurately assess eradication. Either of the 13C-urea breath test or the stool antigen test are viable options for assessing successful eradication.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 9
Incorrect
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Mast cells play a significant part in which of the following?
Your Answer: Killing tumour cells
Correct Answer: Allergic disease
Explanation:Mast cells play a central role in the response to allergen challenges. The activation of mast cells results in both an early and a delayed phase of inflammation. Mast cells have been implicated in both physiologic and pathogenic processes. Mast cells are important in defence against some bacteria and viruses and contribute to defence against parasites. They are key effector cells in both innate and acquired immunity and are capable of inducing and amplifying both types of responses. Specifically, mast cells are capable of detecting microbial products through surface pattern recognition receptors, and they are involved in the recruitment of other leukocytes, containment of bacterial infections, and tissue repair.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 10
Incorrect
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Common causes of exudates are infection, pericarditis, and malignancy.Which one statement about exudates is true?
Your Answer: The fluid protein: serum protein ratio is usually < 0.5
Correct Answer: LDH levels are usually high
Explanation:An exudate is an inflammatory fluid emanating from the intravascular space due to changes in the permeability of the surrounding microcirculation.Exudates are cloudy. It has high LDH levels, serum protein ratio >0.5, protein content >2.9g/dl, specific gravity of >1.020 and a serum-ascites albumin gradient (SAAG) of <1.2g/dl.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 11
Incorrect
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Which of the following intravenous induction drugs results in the highest drop in blood pressure:
Your Answer: Midazolam
Correct Answer: Propofol
Explanation:Propofol’s most frequent side effect is hypotension, which affects 17% of paediatric patients and 26% of adults. This is attributable to systemic vasodilation as well as a decrease in preload and afterload. Propofol has a little negative inotropic impact as well. The drop in blood pressure is dosage-dependent and is more noticeable in the elderly, thus this should be expected.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 12
Correct
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Regarding propofol, which of the following statements is INCORRECT:
Your Answer: A lower induction dose of propofol is required in children.
Explanation:Elderly patients have a reduced volume of distribution and slower clearance of the drug. They are therefore more sensitive to the effects of propofol and the drug wears off more slowly. They need less of the drug, which should be injected slowly, monitoring its effect on the patient. The opposite is true in children, who need larger doses of propofol. This is particularly so in children under three years of age. Propofol is not recommended for induction of anaesthesia in children under one month of age or for maintenance of anaesthesia in children under three years old.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 13
Incorrect
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Mannitol is primarily indicated for which of the following:
Your Answer: Hypertension
Correct Answer: Cerebral oedema
Explanation:Mannitol is an osmotic diuretic that can be used to treat cerebral oedema and raised intraocular pressure. Mannitol is a low molecular weight compound and is, therefore, freely filtered at the glomerulus and is not reabsorbed. It, therefore, increases the osmolality of the glomerular filtrate and tubular fluid, increasing urinary volume by an osmotic effect. It also does not cross the blood-brain-barrier (BBB).
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 14
Incorrect
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Blood flows from the left atrium into the left ventricle via:
Your Answer: The semilunar valves
Correct 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
Incorrect
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The juxtacapillary receptors, or J receptors, are sensory cells that play an important role in the control of respiration.At which of the following anatomical sites are the J receptors located? Select ONE answer only.
Your Answer: The aorta
Correct Answer: The alveolar walls
Explanation:Juxtacapillary receptors (J receptors) are sensory cells that are located within the alveolar walls in juxtaposition to the pulmonary capillaries of the lung.The J receptors are innervated by the vagus nerve and are activated by physical engorgement of the pulmonary capillaries or increased pulmonary interstitial volume, for example, in the presence of pulmonary oedema, pulmonary embolus, pneumonia and barotraumas. They may also be stimulated by hyperinflation of the lung.Stimulation of the J receptors causes a reflex increase in breathing rate and is also thought to be involved in the sensation of dyspnoea. The reflex response that is produced is apnoea, followed by rapid breathing, bradycardia, and hypotension.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 16
Incorrect
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Intrinsic factor is secreted by which of the following cell types in the stomach:
Your Answer: Enterochromaffin-like cell
Correct Answer: Parietal cells
Explanation:Intrinsic factor is essential for the absorption of the small amounts of vitamin B12 normally present in the diet from the terminal ileum. The parietal cells of the stomach produce intrinsic factor, and following a gastrectomy, the absorption of vitamin B12 will be markedly reduced, and a deficiency state will exist.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 17
Incorrect
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Regarding oral rehydration therapy, which of the following statements is INCORRECT:
Your Answer: Diarrhoea is the most common indication for fluid and electrolyte replacement worldwide.
Correct Answer: Oral rehydration solutions should be slightly hyperosmolar.
Explanation:Oral rehydration therapy (ORT) is a fluid replacement strategy used to prevent or treat dehydration. It is less invasive than other strategies for fluid replacement and has successfully lowered the mortality rate of diarrhoea in developing countries. Oral rehydration solutions should be slightly hypo-osmolar (about 250 mmol/litre) to prevent the possible induction of osmotic diarrhoea.ORT contains glucose (e.g. 90 mmol/L in dioralyte). The addition of glucose improves sodium and water absorption in the bowel and prevents hypoglycaemia. It also contains essential mineral salts.Current NICE guidance recommends that 50 ml/kg is given over 4 hours for the treatment of mild dehydration.Once rehydrated, a child should continue with their usual daily fluid intake plus 200 ml ORT after each loose stool. In an infant, give ORT at 1-1.5 x the normal feed volume and in an adult, give 200-400 ml after each loose stool.
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This question is part of the following fields:
- Fluids And Electrolytes
- Pharmacology
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Question 18
Incorrect
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Which of the following microbes binds strongly to CD4 antigen:
Your Answer: Epstein-Barr virus
Correct Answer: HIV
Explanation:HIV mainly infects CD4+ T helper cells. Viral replication results in progressive T-cell depletion and impaired cell-mediated immunity with subsequent secondary opportunistic infections and increased risk of malignancy. B-cell function is also reduced as a result of lack of T-cell stimulation.HIV is not a notifiable disease.
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This question is part of the following fields:
- Microbiology
- Principles
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Question 19
Incorrect
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Where does angiotensin II directly act on the renal nephron:
Your Answer: Thin descending limb
Correct Answer: Proximal tubule
Explanation:Angiotensin II acts to directly increase Na+reabsorption from the proximal tubule (by activating Na+/H+antiporters).
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This question is part of the following fields:
- Physiology
- Renal
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Question 20
Incorrect
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Which of the following is an ECG change typically associated with hyperkalaemia:
Your Answer: T wave inversion
Correct Answer: Wide QRS complex
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
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Question 21
Incorrect
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Regarding probability distribution, which of the following statements is CORRECT:
Your Answer: In skewed data the mean is usually equal to the mode.
Correct Answer: In a negative skew, the mass of distribution is concentrated on the right.
Explanation:Distribution of data is usually unimodal (one peak) but may be bimodal (two peaks) or uniform (no peaks, each value equally likely). The normal distribution is a symmetrical bell-shaped curve. The mean, median, and mode of a normal distribution are equal. In a positive skew, the right tail is longer and the mass of distribution is concentrated on the left; mean > median > mode. In a negative skew, the left tail is longer and the mass of distribution is concentrated on the right; mean < median < mode.
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 22
Correct
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After collapsing at home, a 62-year-old man is transported in an ambulance. He is now awake, but he is experiencing palpitations and chest pain. He is rushed to resuscitation and placed on a cardiac monitor, which reveals ventricular tachycardia. An amiodarone infusion is set up.Which of these statements about amiodarone is correct?
Your Answer: It is expressed in breast milk
Explanation:Antiarrhythmic drug amiodarone is used to treat both ventricular and atrial arrhythmias. It’s a class III antiarrhythmic that works by prolonging the repolarization phase of the cardiac action potential, where potassium permeability is normally high and calcium permeability is low.Dronedarone is sometimes used instead of amiodarone in certain situations. Although amiodarone is more effective than dronedarone, dronedarone has fewer side effects.Grapefruit juice inhibits the metabolism of amiodarone.The plasma half-life of amiodarone is very long, ranging from 2 weeks to 5 months. The half-life is about 2 months on average.Because amiodarone is excreted in breast milk, it should be avoided by breastfeeding mothers.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 23
Incorrect
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A 27-year-old man presents with a laceration of his forearm that severed the nerve that innervates flexor carpi radialis.Which of the following nerves has been damaged in this case? Select ONE answer only.
Your Answer: The anterior interosseous nerve
Correct Answer: The median nerve
Explanation:Flexor carpi radialis is innervated by the median nerve.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 24
Incorrect
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The most important nerves for inversion of the foot are:
Your Answer: Common peroneal nerve
Correct Answer: Tibial and deep fibular nerve
Explanation:Inversion of the foot is achieved by the tibialis anterior which is innervated by the deep fibular nerves, and the tibialis posterior muscles which is innervated by the tibial nerve respectively.
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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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Glomerular filtration rate can be calculated using any substance that:
Your Answer: is not filtered by the nephron
Correct Answer: is freely filtered and neither reabsorbed nor secreted by the nephron
Explanation:Clearance of a substance can provide an accurate estimate of the glomerular filtration rate (GFR) provided that the substance is:freely filterednot reabsorbed in the nephronnot secreted in the nephronnot synthesised or metabolised by the kidney
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This question is part of the following fields:
- Physiology
- Renal
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Question 26
Incorrect
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Among the following microorganisms, which is considered to be transmitted by invasion of intact skin?
Your Answer: Escherichia coli
Correct Answer: Leptospira spp.
Explanation:Rodents and domestic animals are the primary reservoirs for the Leptospira spp, although other animals, including cows, horses, mongooses, and frogs, can also harbour the leptospires. Humans may be directly infected from animal urine or indirectly by contact with soil or water that is contaminated with urine from infected animals. Infected humans can shed leptospires in urine for up to 11 months, infected cows for 3.5 months, infected dogs for 4 years, and infected rodents possibly for their entire lifetime.The organisms enter the host through mucous membranes or abraded skin. The incubation period ranges from 5 to 14 days.
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 27
Incorrect
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Which of the following is NOT an effect of cytokine activity:
Your Answer: Induction of the acute phase response
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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Question 28
Incorrect
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Which of the following clinical features would you NOT expect to see in a tibial nerve palsy:
Your Answer: Loss of plantarflexion of the foot
Correct Answer: Weakened eversion of the foot
Explanation:Damage to the tibial nerve results in loss of plantarflexion of the ankle and weakness of inversion of the foot resulting in a shuffling gait, clawing of the toes and loss of sensation in its cutaneous distribution.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 29
Correct
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A 1-year-old male is brought to the paediatrician by his mother due to swelling of the right knee after a minor fall. On examination, the right knee is swollen, fluctuant and tender. Ultrasound-guided aspiration reveals a massive hemarthrosis. Family history shows that his older brother also has a bleeding disorder. Which one of the following conditions does the patient most likely have?
Your Answer: Haemophilia A
Explanation:A diagnosis of Haemophilia is supported in this patient by the family history and the presence of hemarthrosis-both characteristics of Haemophilia. Haemophilia A is caused by Factor VIII deficiency, leading to impaired coagulation. This disease typically presents after six months when the child starts crawling. Von Willebrand disease presents with nosebleeds and hematomas. Idiopathic thrombocytopenic purpura presents with bruises that resemble a rash. Glucose-6-phosphate dehydrogenase (G6PD) deficiency presents with haemolytic anaemia induced by specific drugs or foods. Factor V Leiden mutation causes blood clotting rather than bleeding.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 30
Incorrect
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Contraction of the diaphragm results in which of the following effects:
Your Answer: Increased intrathoracic pressure
Correct Answer: Increased vertical dimension of the thorax
Explanation:Contraction of the diaphragm (as in inspiration) results in flattening (depression) of the diaphragm with an increase in vertical dimension of the thorax. This results in decreased intrathoracic pressure and increased intra-abdominal pressure.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 31
Correct
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A 32 year old woman presents with episodes of flushing, headaches and palpitations. On examination her blood pressure is significantly elevated. Which of the following is the most likely diagnosis:
Your Answer: Pheochromocytoma
Explanation:Phaeochromocytomas are catecholamine-secreting tumours which occur in about 0.1% of patients with hypertension. In about 90% of cases they arise from the adrenal medulla. The remaining 10%, which arise from extra-adrenal chromaffin tissue, are termed paragangliomas. Common presenting symptoms include one or more of headache, sweating, pallor and palpitations. Less commonly, patients describe anxiety, panic attacks and pyrexia. Hypertension, whether sustained or episodic, is present in at least 90% of patients. Left untreated phaeochromocytoma can occasionally lead to hypertensive crisis, encephalopathy, hyperglycaemia, pulmonary oedema, cardiac arrhythmias, or even death.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 32
Incorrect
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Which of the following is NOT a common side effect of amiodarone:
Your Answer: Pulmonary fibrosis
Correct Answer: Blue/green teeth discolouration
Explanation:Common side effects of amiodarone include: Bradycardia, Nausea and vomiting, Thyroid disorders – hypothyroidism and hyperthyroidism, Persistent slate grey skin discoloration, Photosensitivity, Pulmonary toxicity (including pneumonitis and fibrosis), Hepatotoxicity, Corneal microdeposits (sometimes with night glare), Peripheral neuropathy and Sleep disorders.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 33
Incorrect
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What does the correlation coefficient r = 0 indicate with regards to linear relationships between two variables?
Your Answer: The two variables are directly proportional
Correct Answer: There is no correlation between two variables
Explanation:r = 0 if there is no correlation between two variables. The closer that r is to 0, the weaker the correlation.
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 34
Incorrect
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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: Cefalexin
Correct 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 35
Incorrect
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Which of the following is NOT an advantage of a case-control study used to identify past exposure to a risk factor in patients with a disease:
Your Answer: Particularly suitable for studying association between an exposure and an outcome when the outcome is uncommon
Correct Answer: Can directly measure absolute and relative risk of a disease
Explanation:Advantages:relatively quickrelatively cheap and easy to performparticularly suitable for studying associations between an exposure and an outcome when the outcome is uncommon or if the outcome occurs decades after exposurea wide range of risk factors can be investigated in each studyDisadvantages:subject to recall biasunlike in a whole population study, absolute risk cannot be quantifiedtemporal relationship between exposure and outcome can be difficult to establishunsuitable for rare risk factorsprone to confounding
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This question is part of the following fields:
- Evidence Based Medicine
- Study Methodology
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Question 36
Incorrect
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A 32-year-old asthmatic patient on theophylline as part of her asthma management presents to the Emergency Department with an unrelated medical condition.Which of these drugs should be avoided?
Your Answer: Amitriptyline
Correct Answer: Clarithromycin
Explanation:Macrolide antibiotics (e.g. clarithromycin and erythromycin) are cytochrome P450 enzyme inhibitors. They increase blood levels of theophylline leading to hypokalaemia, and potentially increasing the risk of Torsades de pointes when they are prescribed together. Co-prescription with theophylline should be avoided.Factors that enhance theophylline clearance include cigarette smoking, carbamazepine, phenobarbital, phenytoin, primidone, and rifampin. Medications that inhibit clearance include ethanol, ciprofloxacin, erythromycin, verapamil, propranolol, ticlopidine, tacrine, allopurinol, and cimetidine.
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This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 37
Correct
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The following statements concerning lung compliance is true EXCEPT?
Your Answer: Lung compliance is described by the equation: C = ∆ P/ ∆V, where C = compliance, P = pressure, and V = volume
Explanation:Lung compliance is the change in volume per unit change in distending pressure. It is calculated using the equation:Lung compliance = ΔV / ΔPWhere:ΔV is the change in volumeΔP is the change in pleural pressure.Lung compliance is inversely proportional to stiffness and elastance. It comprises static (no airflow) and dynamic (during continuous breathing) components. It is the slope of the pressure-volume curve.Lung compliance describes the distensibility of the lungs and the chest wall.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 38
Incorrect
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Which of the following statements about sickle cell disease is TRUE:
Your Answer: Sickle cell is inherited in an autosomal dominant pattern.
Correct Answer: Hand-foot syndrome is frequently a first presentation of the disease.
Explanation:Hand-foot syndrome in children is typically the first symptom of the disease, produced by infarction of the metaphysis of small bones. The disease is inherited as an autosomal recessive trait. By adulthood, the spleen has usually infarcted. Infection with the B19 parvovirus is usually followed by an aplastic crisis. Thrombocytopenia is caused by splenic sequestration.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 39
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 40
Incorrect
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All of the following predisposes to lithium toxicity in patients taking long-term therapy EXCEPT:
Your Answer: Dehydration
Correct Answer: Hypernatraemia
Explanation:A common complication of long term lithium therapy results in most cases of lithium intoxication. It is caused by reduced excretion of the drug which can be due to several factors including deterioration of renal function, dehydration, hyponatraemia, infections, and co-administration of diuretics or NSAIDs or other drugs that may interact.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 41
Incorrect
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Which of the following risk ratios indicates no difference in risk between two groups:
Your Answer: ∞
Correct Answer: 1
Explanation:A risk ratio of 1 indicates no difference in risk between groups.If the risk ratio of an event is > 1, the rate of that event is increased in the exposed group compared to the control group.If the risk ratio is < 1, the rate of that event is reduced in the exposed group compared to the control group.
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 42
Incorrect
-
When there is the presence of distended and engorged veins in the umbilical area, which of the following portosystemic anastomoses has most likely occurred?
Your Answer: Para-umbilical veins and left gastric vein
Correct Answer: Para-umbilical veins and inferior epigastric vein
Explanation:Caput medusae is a condition that consists of collateral veins radiating from the umbilicus and results from recanalization of the umbilical vein.Under normal conditions, the portal venous blood traverses the liver and drains into the inferior vena cava of the systemic venous circulation by way of the hepatic veins. This is the direct route. However, other, smaller communications exist between the portal and systemic systems, and they become important when the direct route becomes blocked. These communications are as follows:At the lower third of the oesophagus, the oesophageal branches of the left gastric vein (portal tributary) anastomose with the oesophageal veins draining the middle third of the oesophagus into the azygos veins (systemic tributary).Halfway down the anal canal, the superior rectal veins (portal tributary) draining the upper half of the anal canal anastomosis with the middle and inferior rectal veins (systemic tributaries), which are tributaries of the internal iliac and internal pudendal veins, respectively.The paraumbilical veins connect the left branch of the portal vein with the superficial veins of the anterior abdominal wall (systemic tributaries). The paraumbilical veins travel in the falciform ligament and accompany the ligamentum teres.The veins of the ascending colon, descending colon, duodenum, pancreas, and liver (portal tributary) anastomose with the renal, lumbar, and phrenic veins (systemic tributaries).
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This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 43
Incorrect
-
Regarding the varicella zoster virus, which of the following statements is CORRECT:
Your Answer: Childhood chickenpox should be treated with oral antiviral medication.
Correct Answer: Contracting chickenpox infection while pregnant is associated with a higher risk of developing varicella pneumonitis.
Explanation:Chickenpox infection in neonates, adults/adolescents and pregnant women is associated with more severe disease. Varicella zoster pneumonitis typically occurs in pregnant women or immunocompromised individuals and is associated with a high mortality. A live attenuated-virus vaccine is available and recommended for non-immune healthcare workers but is not part of the routine childhood immunisation schedule. Antiviral treatment is not typically recommended in childhood chickenpox but is indicated for shingles.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 44
Incorrect
-
The movement of molecules across the cell membrane relies greatly on active transport.Which of the following statements about active transport is correct?
Your Answer: Primary active transport involves the use of an electrochemical gradient
Correct Answer: Active transport occurs in glucose absorption from the gut
Explanation:The movement of a material against a concentration gradient, i.e. from a low to a high concentration, is known as active transport. Primary active transport is defined as active transport that involves the use of chemical energy, such as adenosine triphosphate (ATP). Secondary active transport occurs when an electrochemical gradient is used.The sodium-potassium pump, calcium ATPase pump, and proton pump are all key active transport systems that use ATP. An electrochemical gradient is used by the sodium-calcium co-transporter, which is an example of secondary active transport.The sodium-dependent hexose transporter SGLUT-1 transports glucose and galactose into enterocytes. Secondary active transport is exemplified here.
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 45
Incorrect
-
A 40-year-old man who has a history of asthma arrives at the emergency department complaining of palpitations that have been going on for 5 days. Which of the following beta-blockers is the safest for an asthmatic patient?
Your Answer: Propranolol
Correct Answer: Atenolol
Explanation:Atenolol is a beta blocker, which is a type of medication that works by preventing certain natural substances in the body, such as epinephrine, from acting on the heart and blood vessels. This effect reduces heart rate, blood pressure, and cardiac strain. Atenolol, bisoprolol fumarate, metoprolol tartrate, nebivolol, and (to a lesser extent) acebutolol have a lower action on beta2 (bronchial) receptors and are thus cardio selective but not cardiac specific. They have a lower effect on airway resistance, although they are not without this adverse effect.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 46
Correct
-
During bedside rounds, an 82-year old female in the Medicine Ward complains of pain and tingling of all fingers of the right hand. The attending physician is considering carpal tunnel syndrome.Which of the following is expected to undergo atrophy in carpal tunnel syndrome?
Your Answer: The thenar eminence
Explanation:Carpal tunnel syndrome (CTS) is an entrapment neuropathy caused by compression of the median nerve as it travels through the wrist’s carpal tunnel. It is the most common nerve entrapment neuropathy, accounting for 90% of all neuropathies. Early symptoms of carpal tunnel syndrome include pain, numbness, and paraesthesia’s. These symptoms typically present, with some variability, in the thumb, index finger, middle finger, and the radial half (thumb side) of the ring finger. Pain also can radiate up the affected arm. With further progression, hand weakness, decreased fine motor coordination, clumsiness, and thenar atrophy can occur.The muscles innervated by the median nerve can be remembered using the mnemonic ‘LOAF’:L– lateral two lumbricalsO– Opponens pollicisA– Abductor pollicisF– Flexor pollicis brevisIn the early presentation of the disease, symptoms most often present at night when lying down and are relieved during the day. With further progression of the disease, symptoms will also be present during the day, especially with certain repetitive activities, such as when drawing, typing, or playing video games. In more advanced disease, symptoms can be constant.Typical occupations of patients with carpal tunnel syndrome include those who use computers for extended periods of time, those who use equipment that has vibration such as construction workers, and any other occupation requiring frequent, repetitive movement.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 47
Correct
-
A 42-year-old patient with worsening epigastric pain has been referred to you by a GP. The patient has been taking omeprazole for a month, but her symptoms are getting worse.Which of the following is NOT a well-known side effect of proton pump inhibitor treatment?
Your Answer: Pelvic fracture
Explanation:Proton pump inhibitors (PPIs) have a variety of side effects, including:Vomiting and nauseaPain in the abdomenFlatulenceDiarrhoeaConstipationHeadachePPIs have been linked to a significant increase in the risk of focal tachyarrhythmias (link is external).Low serum magnesium and sodium levels have been linked to long-term use of PPIs, according to the US Food and Drug Administration (link is external).Long-term PPI use has also been linked to an increased risk of fracture, according to epidemiological evidence (link is external). Observational studies have discovered a slight link between hip, wrist, and spine fractures. However, there is no link between the two and an increased risk of pelvic fracture. For this reason, the MHRA recommends that patients at risk of osteoporosis who take PPIs maintain an adequate calcium and vitamin D intake.
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This question is part of the following fields:
- Gastrointestinal Pharmacology
- Pharmacology
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Question 48
Incorrect
-
The action potential is generated by excitable tissues, which are specialized tissues that can generate a meaningful electrical signal. Local currents transport action potentials down the axons of neurons.Which of the following claims about the action potential's conduction is correct?Â
Your Answer: There are periodic gaps along a myelinate axon called Bouchard’s nodes
Correct Answer: The areas of the membrane that have recently depolarised will not depolarise again due to the refractory period
Explanation:Local currents propagate action potentials down the axons of neurons. Following depolarization, this local current flow depolarizes the next axonal membrane, and when this region crosses the threshold, more action potentials are formed, and so on. Due to the refractory period, portions of the membrane that have recently depolarized will not depolarize again, resulting in the action potential only being able to go in one direction.The square root of axonal diameter determines the velocity of the action potential; the axons with the biggest diameter have the quickest conduction velocities. When a neuron is myelinated, the speed of the action potential rises as well.The myelin sheath is an insulating coating that surrounds certain neural axons. By increasing membrane resistance and decreasing membrane capacitance, the myelin coating increases conduction. This enables faster electrical signal transmission via a neuron, making them more energy-efficient than non-myelinated neuronal axons.Nodes of Ranvier are periodic holes in a myelinate axon when there is no myelin and the axonal membrane is exposed. There are no gated ion channels in the portion of the axon covered by the myelin sheath, but there is a high density of ion channels in the Nodes of Ranvier. Action potentials can only arise at the nodes as a result of this.Electrical impulses are quickly transmitted from one node to the next, causing depolarization of the membrane above the threshold and triggering another action potential, which is then transmitted to the next node. An action potential is rapidly conducted down a neuron in this manner. Saltatory conduction is the term for this.
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 49
Correct
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You examine a 73-year-old patient who is experiencing a worsening of his chronic heart failure. Bumetanide was recently prescribed for him.Which of the following statements about bumetanide is correct?
Your Answer: It has better intestinal absorption than furosemide
Explanation:Bumetanide is a loop diuretic that inhibits sodium, chloride, and potassium reabsorption by acting on the Na.K.2Cl co-transporter in the ascending loop of Henlé. This reduces the osmotic gradient that forces water out of the collecting duct system and prevents the formation of a hypertonic renal medulla. This has a strong diuretic effect on the body.It’s primarily used in patients with heart failure who aren’t responding to high doses of furosemide. Bumetanide and furosemide differ primarily in terms of bioavailability and pharmacodynamic potency.In the intestine, furosemide is only partially absorbed, with a bioavailability of 40-50 percent. Bumetanide, on the other hand, is almost completely absorbed in the intestine and has a bioavailability of about 80%. Bumetanide is 40 times more potent than furosemide, and one milligram is roughly equivalent to 40 milligrams of furosemide.Bumetanide also lowers the concentration of neuronal chloride, making GABA’s action more depolarizing. In the neonatal period, it is being studied as an antiepileptic.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 50
Incorrect
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You are instructed by a senior to administer Mannitol to an RTA patient with increased intracranial pressure. Mannitol is a low molecular weight compound that freely filters at the glomerulus and is not reabsorbed.Out of the following, which is a contraindication to the use of mannitol?
Your Answer: Jaundice
Correct Answer: Severe pulmonary oedema
Explanation:Mannitol is the most widely used osmotic diuretic that is most commonly used to reduce cerebral oedema and intracranial pressure. It is recommended to use mannitol for the reduction of CSF pressure/cerebral oedema in a dose of 0.25-2 g/kg as an intravenous infusion over 30-60 minutes. This can be repeated 1-2 times after 4-8 hours if needed.Mannitol has several contraindications and some of them are listed below:1. Anuria due to renal disease2. Acute intracranial bleeding (except during craniotomy)3. Severe cardiac failure4. Severe dehydration5. Severe pulmonary oedema or congestion6. Known hypersensitivity to mannitol
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 51
Incorrect
-
Which of the following vitamins is not paired correctly with its deficiency syndrome:
Your Answer: Vitamin D - Osteomalacia
Correct Answer: Vitamin B12 - Wernicke-Korsakoff syndrome
Explanation:Clinical Effects of vitamin deficiency include:Vitamin C – ScurvyThiamine (Vitamin B1) – Beriberi/Wernicke-Korsakoff syndromeVitamin B12 – Megaloblastic anaemia/Subacute combined degeneration of spinal cordFolate – Megaloblastic anaemiaVitamin D – Osteomalacia/RicketsVitamin K – Defective clottingVitamin A – Blindness
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 52
Incorrect
-
Adrenocorticotropic hormone release from the anterior pituitary is stimulated by which of the following:
Your Answer: Thyrotropin-releasing hormone
Correct Answer: Corticotropin-releasing hormone
Explanation:ACTH secretion is stimulated by corticotropin-releasing hormone (CRH) from the hypothalamus.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 53
Incorrect
-
A 18-year-old man returns from a trip to Ibiza with a severely painful left eye. He has copious mucopurulent discharge, is febrile and has left-sided tender preauricular lymphadenopathy. He attends the local eye casualty and is diagnosed with hyperacute conjunctivitis.What is the SINGLE most likely causatiave organism?
Your Answer: Chlamydia trachomatis
Correct Answer: Neisseria gonorrhoeae
Explanation:Hyperacute bacterial conjunctivitis is a severe, sight-threatening ocular infection that warrants immediate ophthalmic work-up and management. The infection has an abrupt onset and is characterized by a copious yellow-green purulent discharge that reaccumulates after being wiped away. Typically caused by infection with Neisseria gonorrhoeae.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 54
Incorrect
-
Which of these is NOT a lithium side effect:
Your Answer: Muscle weakness
Correct Answer: Peptic ulcer disease
Explanation:Adverse Effects of lithium IncludeLeucocytosis (most patients)Polyuria/polydipsia (30-50%)Dry mouth (20-50%)Hand tremor (45% initially, 10% after 1 year of treatment)Confusion (40%)Decreased memory (40%)Headache (40%)Muscle weakness (30% initially, 1% after 1 year of treatment)Electrocardiographic (ECG) changes (20-30%)Nausea, vomiting, diarrhoea (10-30% initially, 1-10% after 1-2 years of treatment)Hyperreflexia (15%)Muscle twitch (15%)Vertigo (15%)Extrapyramidal symptoms, goitre (5%)Hypothyroidism (1-4%)Acne (1%)Hair thinning (1%)
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 55
Incorrect
-
A patient complains of headache and visual loss. CT scan demonstrates a lesion of the temporal lobe. What type of visual field defect would you most expect to see in this patient:
Your Answer: Homonymous hemianopia with macular sparing
Correct Answer: Contralateral homonymous superior quadrantanopia
Explanation:Axons from the lateral geniculate nucleus (LGN) carry visual information, via the upper and lower optic radiations, to the visual cortex in the occipital lobe:The upper optic radiation carries fibres from the superior retinal quadrants (corresponding to the inferior visual field quadrants) and travels through the parietal lobe to reach the visual cortex. The lower optic radiation carries fibres from the inferior retinal quadrants (corresponding to the superior visual field quadrants) and travels through the temporal lobe to reach the visual cortex of the occipital lobe.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 56
Correct
-
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 57
Incorrect
-
In a 7-year-old child with chickenpox, which of the following would you advise the mother NOT to do?
Your Answer: Use anti-histamines to help ease the itching
Correct Answer: Give ibuprofen for the fever
Explanation:Chickenpox (varicella zoster) is a highly contagious airborne disease and has an incubation period of between 7-21 days. It often has a prodromal phase when there is a fever, aches and headaches, dry cough, and sore throat before onset of rash.Some recognized complications of chickenpox are:OrchitisHepatitisPneumoniaEncephalitisInfected spotsOtitis mediaMyocarditisGlomerulonephritisAppendicitisPancreatitisTreatment is symptomatic and includes using paracetamol to manage fever. There is a link between use of ibuprofen in patients with chicken-pox and necrotizing fasciitis so Ibuprofen should NOT be used. An emollient and antihistamine can be used to ease the itchy rash and oral hydration is encouraged.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 58
Incorrect
-
Which of the following drugs used in the management of hyperkalaemia does not affect serum potassium levels:
Your Answer: Salbutamol
Correct Answer: Calcium gluconate
Explanation:Calcium gluconate is given to antagonise cardiac cell membrane excitability to reduce the risk of arrhythmias. It has no effect on serum potassium levels unlike the alternative drugs listed above.
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This question is part of the following fields:
- Fluids And Electrolytes
- Pharmacology
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Question 59
Incorrect
-
Regarding saliva, which of the following statements is CORRECT:
Your Answer: At rest, saliva is predominantly produced by the parotid gland.
Correct 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 60
Incorrect
-
You review a 50-year-old man that is requesting the seasonal influenza vaccination.Which of the following single clinical risk groups is NOT eligible to receive the seasonal influenza vaccination? Select ONE answer only.
Your Answer: All pregnant women
Correct Answer: Patients over the age of 50
Explanation:Patients with hypertension are only eligible for the seasonal influenza vaccination if they have co-existent cardiac complications.The UK national policy is that the seasonal influenza vaccine should be offered to the following groups:All those aged 65 years and olderChildren aged 2 to 15 yearsResidents of nursing and residential homes for the elderly (and other long-stay facilities)Carers of persons whose welfare may be at risk if the carer falls illAll those aged 6 months or older in a clinical risk groupThe following table outlines the clinical risk groups that are considered eligible for the vaccine:CategoryExamples of eligible groupsRespiratory diseaseCOPDInterstitial lung diseaseCystic fibrosisAsthma (requiring oral or inhaled steroids)Heart diseaseCongenital heart diseaseChronic heart failureCoronary heart disease (requiring medication and/or follow-up)Hypertension with cardiac complicationsKidney diseaseChronic kidney diseaseNephrotic syndromeRenal transplant patientsLiver diseaseLiver cirrhosisChronic hepatitisBiliary atresiaNeurological diseaseCerebrovascular accidentTransient ischaemic attackEndocrine diseaseType 1 and 2 diabetesImmunosuppressionPatients undergoing chemotherapyPatients taking immunosuppressive drug therapy (including systemic steroids)Asplenia or splenic dysfunctionHIV infectionPregnancyAll pregnant women
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 61
Incorrect
-
Which of the following cytokines is important for the maintenance of granulomatous inflammation:
Your Answer: IL- 10
Correct Answer: TNF-alpha
Explanation:Granulomatous inflammation is a distinctive pattern of chronic inflammation that is encountered in a limited number of infectious and some non-infectious conditions. Briefly, a granuloma is a cellular attempt to contain an offending agent that is difficult to eradicate. In this attempt, there is often strong activation of T lymphocytes leading to macrophage activation, which can cause injury to normal tissues. IL-1 is important in initiating granuloma formation, IL-2 can cause them to enlarge and TNF-α maintains them.
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This question is part of the following fields:
- Inflammatory Responses
- Pathology
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Question 62
Incorrect
-
Pressure across the wall of a flexible tube (the transmural pressure) increases wall tension and extends it.Which law best describes transmural pressure?
Your Answer: Fick’s law
Correct Answer: Laplace’s law
Explanation:The transmural pressure (pressure across the wall of a flexible tube) can be described by Laplace’s law which states that:Transmural pressure = (Tw) / rWhere:T = Wall tensionw = Wall thicknessr = The radiusA small bubble with the same wall tension as a larger bubble will contain higher pressure and will collapse into the larger bubble if the two meet and join.Fick’s law describes the rate of diffusion in a solutionPoiseuille’s law is used to calculate volume of flow rate in laminar flowDarcy’s law describes the flow of a fluid through a porous medium.Starling’s law describes cardiac haemodynamics as it relates to myocyte contractility and stretch.
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 63
Correct
-
You see a patient in the Emergency Department with features consistent with a diagnosis of type I diabetes mellitus.Which of these is MOST suggestive of type I diabetes mellitus?
Your Answer: History of recent weight loss
Explanation:A history of recent weight loss is very suggestive of an absolute deficiency of insulin seen in type I diabetes mellitus.An age of onset of less than 20 years makes a diagnosis of type I diabetes mellitus more likely. However, an increasing number of obese children and young people are being diagnosed with type II diabetes.Microalbuminuria, peripheral neuropathy, and retinopathy all occur in both type I and type II diabetes mellitus. They are not more suggestive of type I DM.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 64
Incorrect
-
Which of the following comprises a negative feedback mechanism?
Your Answer: Detectors, amplifiers, comparators, a fixed set point and effectors
Correct Answer: Detectors, comparators, a variable set point and effectors
Explanation:Negative feedback loops, also known as inhibitory loops, play a crucial role in controlling human health. It is a self-regulating mechanism of some sort. A negative feedback system is made up of three main components: a detector (often neural receptor cells) that measures the variable in question and provides input to the comparator; a comparator (usually a neural assembly in the central nervous system) that receives input from the detector, compares the variable to the variable set point, and determines whether or not a response is required. The comparator activates an effector (typically muscular or glandular tissue) to conduct the appropriate reaction to return the variable to its set point.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 65
Correct
-
The following are all examples of type III hypersensitivity EXCEPT for:
Your Answer: Goodpasture's syndrome
Explanation:Examples of type III reactions include:Extrinsic allergic alveolitisSystemic lupus erythematosus (SLE)Post-streptococcal glomerulonephritisReactive arthritisRheumatoid arthritis
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 66
Incorrect
-
A 25 year old woman who is a known diabetic is brought to the ED with diabetic ketoacidosis. She promptly received an insulin infusion. Which of the following are expected to increase upon infusion of insulin?
Your Answer: Respiratory rate
Correct Answer: Blood pH
Explanation:Ketoacidosis is characterized by hyperglycaemia, glycosuria, hyperkalaemia, and metabolic acidosis with respiratory compensation. An insulin infusion would be able to address these by lowering blood glucose through increased insulin-mediated cellular uptake, lowering urine glucose concentration as cellular glucose uptake is increased, decreasing K+ in her blood by shifting it into cells, and increasing blood ph by addressing the metabolic acidosis. The metabolic acidosis is addressed by the reduction of ketoacids production thereby returning her blood ph to normal and reducing the need for compensatory hyperventilation.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 67
Incorrect
-
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: Absent P waves
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 68
Incorrect
-
The Meissner’s plexus acts as the main control for gastrointestinal secretion and local blood flow within the gut.The Meissner’s plexus lies in which layer of the gut wall?
Your Answer: Subserosa
Correct Answer: Submucosa
Explanation:The Meissner’s plexus (submucosal plexus), an enteric nervous plexus, acts as the main control for gastrointestinal secretion and local blood flow within the gut.It is located in the submucosal layer on the inner surface of the muscularis externa.
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This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 69
Incorrect
-
An analytical cohort study aimed to determine a relationship between intake of dietary calcium and incidence of hip fractures among post-menopausal women. The following are the data obtained from the study:No. of post-menopausal women who took Calcium: 500No. of post-menopausal women who took Calcium and suffered a hip fracture: 10No. of post-menopausal women who took placebo: 500No. of post-menopausal women who took placebo and suffered a hip fracture: 25Compute for the risk ratio of a hip fracture.
Your Answer: 0.03
Correct Answer: 0.4
Explanation:Relative risk (RR) is a ratio of the probability of an event occurring in the exposed group versus the probability of the event occurring in the non-exposed group.RR can be computed as the absolute risk of events in the treatment group (ART), divided by the absolute risk of events in the control group (ARC).RR = ART/ARCRR = (10/500) / (25/500)RR = 0.4Recall that:If RR < 1, then the intervention reduces the risk of the outcome.If RR = 1, then the treatment has no effect on the outcome.If RR > 1, then the intervention increases the risk of the outcome.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 70
Incorrect
-
A 40-year-old woman presents with a red, scaly, itchy rash around her navel that occurred after contact with a nickel belt buckle. A diagnosis of allergic contact dermatitis is made. Which type of hypersensitivity reaction is this?
Your Answer: Type II hypersensitivity reaction
Correct Answer: Type IV hypersensitivity reaction
Explanation:A type IV hypersensitivity reaction occurred in this patient. Allergic contact dermatitis is an inflammatory skin reaction occurring in response to an external stimulus, acting either as an allergen or an irritant, caused by a type IV or delayed hypersensitivity reaction. They usually take several days to develop.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 71
Incorrect
-
You review a 37-year-old man with a history of intravenous drug abuse who admits to sharing needles in the past. He has a flu-like illness and a rash. Concerned he may be experiencing an HIV seroconversion illness, you order a test.Which of these tests is most reliably used to diagnose HIV at this stage?
Your Answer: ‘Rapid HIV test’
Correct Answer: p24 antigen test
Explanation:Serum concentrations of the p24 antigen are usually high in the first few weeks after human immunodeficiency virus (HIV) infection and testing for p24 antigen is therefore a useful way of diagnosing very early infection. P24 is the viral protein that makes up most of the core of the HIV.ELISA and other antibody tests, though a very sensitive way of detecting the presence of HIV, cannot be used in the early stages of the disease. This is because of the window period of 6-12 weeks before antibodies are produced. These tests will be negative during a seroconversion illness.The ‘rapid HIV test’ is an HIV antibody test. It will also be negative during the ‘window period’ since it takes time for antibodies to be produced. It is called the ‘rapid test’ as it can detect antibodies in blood or saliva much quicker than the other antibody tests and results are often back within 20 minutes.CD4 and CD8 counts are usually normal in the early stages of the HIV infection and cannot be used in this case.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 72
Incorrect
-
A patients had a left Colles' fracture, which you were able to repair. It was their second fragility fracture this year, and you'd like to provide them some tips on how to keep their bones healthy.What percentage of the calcium in the body is kept in the bones? Only ONE response is acceptable.
Your Answer: 25%
Correct Answer: 99%
Explanation:Calcium is stored in bones for nearly all of the body’s calcium, but it is also found in some cells (most notably muscle cells) and the blood. The average adult diet comprises roughly 25 mmol of calcium per day, of which the body absorbs only about 5 mmol.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 73
Incorrect
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All of the following statements are considered true regarding likelihood ratios, except:
Your Answer: The likelihood ratio for a positive test = sensitivity / (1-specificity)
Correct Answer: If less than one, indicates that the information increases the likelihood of the suspected diagnosis
Explanation:The Likelihood Ratio (LR) is the likelihood that a given test result would be expected in a patient with the target disorder compared to the likelihood that that same result would be expected in a patient without the target disorder.The LR is used to assess how good a diagnostic test is and to help in selecting an appropriate diagnostic tests or sequence of tests. They have advantages over sensitivity and specificity because they are less likely to change with the prevalence of the disorder, they can be calculated for several levels of the symptom/sign or test, they can be used to combine the results of multiple diagnostic test and they can be used to calculate post-test probability for a target disorder.A LR greater than 1 produces a post-test probability which is higher than the pre-test probability. An LR less than 1 produces a post-test probability which is lower than the pre-test probability. When the pre-test probability lies between 30 and 70 per cent, test results with a very high LR (say, above 10) rule in disease. An LR below 1 produces a post-test probability les than the pre-test probability. A very low LR (say, below 0.1) virtually rules out the chance that the patient has the disease.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 74
Incorrect
-
A suspicious growth on the posterior tongue of a 40-year-old man was discovered by his dentist and was immediately referred for possible oral cancer. The lymph from the posterior tongue will drain to which of the following nodes?
Your Answer: Inferior cervical nodes
Correct Answer: Deep cervical nodes
Explanation:Lymph from the medial anterior two thirds of the tongue travels to the deep cervical lymph nodes.Lymph from the lateral anterior tongue goes to the submandibular nodes.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 75
Incorrect
-
An analytical study is conducted to compare the risk of stroke between Ticagrelor therapy and Warfarin therapy among patients with atrial fibrillation. The following is obtained from the study:No. of patients who took Ticagrelor: 300No. of patients who took Ticagrelor and suffered a stroke: 30No. of patients who took Warfarin: 500No. of patients who took Warfarin and suffered a stroke: 20Compute for the risk ratio of a stroke.
Your Answer: -0.06
Correct Answer: 2.5
Explanation:Relative risk (RR) is a ratio of the probability of an event occurring in the exposed group versus the probability of the event occurring in the non-exposed group.RR can be computed as the absolute risk of events in the treatment group (ART), divided by the absolute risk of events in the control group (ARC).RR = ART/ARCRR = (30/300) / (20/500)RR = 2.5Recall that:If RR < 1, then the intervention reduces the risk of the outcome.If RR = 1, then the treatment has no effect on the outcome.If RR > 1, then the intervention increases the risk of the outcome.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 76
Correct
-
Regarding defaecation, which of the following statements is CORRECT:
Your Answer: Colonic mass movement occurs shortly after a meal due to distension of the stomach and duodenum.
Explanation:Colonic mass movement describes the intense contraction that begins halfway along the transverse colon and pushes the intestinal contents in the proximal colon towards the rectum. It occurs shortly after a meal due to distension of the stomach and duodenum as part of the gastrocolic reflex and if faeces is present in the rectum, stimulates the urge to defecate. Distention of the rectum causes firing of afferent cholinergic parasympathetic fibres. The internal sphincter is made up of circular smooth muscle innervated by the autonomic fibres, and the more distal external sphincter is composed of striated muscle innervated by motor fibres from the pudendal nerve. During defaecation, relaxation of pelvic muscles straightens the rectum.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 77
Incorrect
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Question 78
Correct
-
Which of the following is the most likely causative organism of acute epiglottitis in a 6 year old?
Your Answer: Streptococcus pneumoniae
Explanation:Since the introduction of the HIB vaccine, most cases of acute epiglottitis are now caused by Streptococcus spp. The condition is now rare in children.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 79
Incorrect
-
Regarding tapeworm, which of the following statements is CORRECT:
Your Answer: Humans may be infected by pork tapeworm or poultry tapeworm.
Correct Answer: Diagnosis is by direct visualisation of characteristic eggs in the stool.
Explanation:Diagnosis of tapeworm is by direct visualisation of characteristic eggs in stool. Humans may be infected by pork or beef tapeworm. Treatment is with praziquantel or niclosamide. Specialist advice should be sought for the management of neurocysticercosis.Iron-deficiency anaemia is typically seen in hookworm infection. Threadworms migrate from the intestine at night to lay eggs on the perianal skin. Mebendazole is first line treatment for threadworms.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 80
Incorrect
-
A 35-year-old man, who was feeling unwell after his return from a business trip, was diagnosed with a disease that is known to be transmitted by a vector. Among the following microorganisms, which of the following has a mode of transmission of being vector-borne?
Your Answer: Mycobacterium tuberculosis
Correct Answer: Plasmodium falciparum
Explanation:Plasmodium falciparum is a parasite that is vector-borne which is transmitted by the female Anopheles mosquito.Bordetella pertussis is transmitted through the respiratory tract, via respiratory droplets or direct contact with infectious secretions.Mycobacterium tuberculosis is transmitted via inhalation of infected respiratory droplets.HIV may be transmitted via sexual contact, vertical transmission from mothers to infants, and among injection drug users sharing infected needles, as well as through transfusion of infected blood products.Treponema pallidum transmission normally occurs during direct sexual contact with an individual who has an active primary or secondary syphilitic lesion.
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 81
Incorrect
-
A 45-old woman is on several medications and being treated for epilepsy and bipolar disorder. In the ward rounds, you are asked to examine her in detail and discover she has a noticeable tremor. You believe that one of her medications may be responsible for this new onset tremor. Which of the following medications is least likely to be responsible for this tremor?
Your Answer: Quetiapine
Correct Answer: Carbamazepine
Explanation:The only medication that does not commonly cause tremors is carbamazepine.The other drugs present with the following types of tremors as a side effect to their usage:1. Sodium valproate – Postural tremor is most common, but a resting tremor can also occur. Approximately 25% of patients taking sodium valproate are found to develop a tremor within 12 months of starting therapy.2. Lithium – fine hand tremor is very commonly seen and reported in as many as 50% of patients during the first week of therapy. The tremor tends to reduce with time and is only present in around 5% of patients taking the medication two years or longer.3. Atypical antipsychotics, such as olanzapine and quetiapine – tremor and limb shakiness.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 82
Incorrect
-
A patient in a high-dependency unit complains of severe and painful muscle cramps. His total corrected plasma calcium level is 1.90 mmol/L.What is the most likely underlying cause?
Your Answer: Lithium
Correct Answer: Rhabdomyolysis
Explanation:Hypocalcaemia occurs when there is abnormally low level of serum calcium ( >2.2 mmol/l) after correction for the serum albumin concentration.Rhabdomyolysis causes hyperphosphatemia, and this leads to a reduction in ionised calcium levels.Patients with rhabdomyolysis are commonly cared for in a high dependency care setting. Addison’s disease, hyperthyroidism, thiazide diuretics and lithium all cause hypercalcaemia.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 83
Incorrect
-
A trauma victim who has been intubated is tachycardic, hypotensive, and has a poor urine output. You feel she is dehydrated and decide to use a central venous catheter to help you manage her. As part of this, you keep an eye on the waveform of central venous pressure (CVP).Which of the following cardiac cycle phases corresponds to the CVP waveform's 'a wave'?Â
Your Answer: Early diastole
Correct Answer: End diastole
Explanation:The pressure measured in the right atrium or superior vena cava is known as central venous pressure (CVP). In a spontaneously breathing subject, the usual CVP value is 0-8 cmH2O (0-6 mmHg).The structure of the CVP waveform is as follows:The CVP’s components are listed in the table below:Component of the waveformThe cardiac cycle phase.mechanical eventmechanical event Diastole Atrial contractiona wave C  wave v waveEarly systoleThe tricuspid valve closes and bulges Late Systole Filling of the atrium with systolic blood x descenty descentMid systoleRelaxation of the atrium Early diastoleFilling of the ventricles at an early stage
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This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
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Question 84
Correct
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Regarding linear relationships between two variables, what does a positive correlation coefficient indicate:
Your Answer: The two variables are directly proportional
Explanation:A positive correlation coefficient means that the two variables are directly proportional e.g. height and weight in healthy growing children.
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 85
Incorrect
-
Regarding haemoglobin, which of the following statements is CORRECT:
Your Answer: Foetal haemoglobin remains the primary haemoglobin in infants up until about 1 year of age.
Correct Answer: In degradation of haemoglobin, the haem group is split from the haemoglobin and converted to biliverdin and ultimately to bilirubin.
Explanation:Haemoglobin is composed of four polypeptide globin chains each with its own iron containing haem molecule. Haem synthesis occurs largely in the mitochondria by a series of biochemical reactions commencing with the condensation of glycine and succinyl coenzyme A under the action of the key rate-limiting enzyme delta-aminolevulinic acid (ALA) synthase. The globin chains are synthesised by ribosomes in the cytosol. Haemoglobin synthesis only occurs in immature red blood cells.There are three types of haemoglobin in normal adult blood: haemoglobin A, A2 and F:- Normal adult haemoglobin (HbA) makes up about 96 – 98 % of total adult haemoglobin, and consists of two alpha (α) and two beta (β) globin chains. – Haemoglobin A2 (HbA2), a normal variant of adult haemoglobin, makes up about 1.5 – 3.5 % of total adult haemoglobin and consists of two α and two delta (δ) globin chains.- Foetal haemoglobin is the main Hb in the later two-thirds of foetal life and in the newborn until approximately 12 weeks of age. Foetal haemoglobin has a higher affinity for oxygen than adult haemoglobin. Red cells are destroyed by macrophages in the liver and spleen after , 120 days. The haem group is split from the haemoglobin and converted to biliverdin and then bilirubin. The iron is conserved and recycled to plasma via transferrin or stored in macrophages as ferritin and haemosiderin. An increased rate of haemoglobin breakdown results in excess bilirubin and jaundice.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 86
Incorrect
-
Regarding Clostridium difficile, which of the following statements is CORRECT:
Your Answer: It has endotoxin-mediated effects causing profuse watery diarrhoea.
Correct Answer: It is normally found in gut flora.
Explanation:C. difficile is normally found in the gut flora but its growth is normally suppressed by more dominant anaerobes. It has exotoxin-mediated effects causing profuse diarrhoea. Oral clindamycin (a broad spectrum antibiotic) is commonly implicated in precipitating C. difficile colitis; first line treatment is with oral metronidazole. Tetanolysin is a toxin produced by Clostridium tetani bacteria.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 87
Incorrect
-
Which of the following microbes produces exotoxin:
Your Answer: Mycoplasma tuberculosis
Correct Answer: Clostridium tetani
Explanation:Clostridium tetani (causing tetanus) produces the exotoxin tetanospasmin which causes its neurotoxic effects.
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This question is part of the following fields:
- Microbiology
- Principles
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Question 88
Incorrect
-
Regarding antacids, which of the following statements is CORRECT:
Your Answer: Antacids are best taken regularly each morning for maximum symptom control.
Correct Answer: Antacids are contraindicated in hypophosphataemia.
Explanation:Antacids are contraindicated in hypophosphataemia. Liquid preparations are more effective than tablet preparations. Magnesium-containing antacids tend to be laxative whereas aluminium-containing antacids tend to be constipating. Antacids are best taken when symptoms occur or are expected, usually between meals and at bedtime. Antacids should preferably not be taken at the same time as other drugs since they may impair absorption.
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This question is part of the following fields:
- Gastrointestinal
- Pharmacology
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Question 89
Incorrect
-
A 62-year-old man complains of chest pain and goes to the emergency room. You diagnose him with an acute coronary syndrome and prescribe enoxaparin as part of his treatment plan.Enoxaparin inactivates which of the following?
Your Answer: Factor VII
Correct Answer: Thrombin
Explanation:Enoxaparin is a low molecular weight heparin (LMWH) that works in the same way as heparin by binding to and activating the enzyme inhibitor antithrombin III. Antithrombin III inactivates thrombin by forming a 1:1 complex with it. Factor Xa and a few other clotting proteases are also inhibited by the heparin-antithrombin III complex.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 90
Correct
-
Beta cells of the endocrine pancreas produce which of the following hormones:
Your Answer: Insulin
Explanation:Insulin is produced by beta cells, located centrally within the islets of Langerhans, in the endocrine tissues of the pancreas. Insulin is a polypeptide hormone consisting of two short chains (A and B) linked by disulphide bonds. Proinsulin is synthesised as a single-chain peptide. Within storage granules, a connecting peptide (C peptide) is removed by proteases to yield insulin. Insulin release is stimulated initially during eating by the parasympathetic nervous system and gut hormones such as secretin, but most output is driven by the rise in plasma glucose concentration that occurs after a meal. The effects of insulin 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 91
Incorrect
-
What is the main mechanism of action of dopamine as an inotropic sympathomimetic:
Your Answer: Alpha1-receptor agonist
Correct Answer: Beta1-receptor agonist
Explanation:Dopamine is a neurotransmitter and a metabolic precursor of the catecholamines. It acts on beta1-receptors in cardiac muscle increasing cardiac contractility, and increases renal perfusion by stimulating dopamine receptors in the renal vasculature. This is of benefit in cardiogenic shock where deterioration of renal function is common.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 92
Incorrect
-
A 20-year-old male receives a small cut over his hand while climbing a fence causing it to bleed. Upon applying pressure for a few minutes, the bleeding stops. Which one of the following physiological components of the blood is responsible for the primary haemostasis reaction, such as in this case?
Your Answer: Activation of factor X
Correct Answer: Platelet plug formation
Explanation:Haemostasis is your body’s defence against an injury that causes bleeding. It stops bleeding in three main steps: 1) Primary haemostasis – formation of a weak platelet plug- The primary reaction of the body is to cause local vasoconstriction at the site of injury and decrease blood flow to the affected area- the release of cytokines and inflammatory markers lead to adhesion of platelets and aggregation at the site of injury forming a platelet plug- the injured vessel wall has exposed subendothelial collagen that releases von Willebrand factor Any damage to the vessel wall causes the release of the Von Willebrand factor, which is necessary for platelet adhesion. Tissue Thromboplastin is also released, which activates the coagulation pathway, a component of secondary haemostasis. The coagulation cascade ultimately results in the conversion of fibrinogen to fibrin.2) Secondary haemostasis 3) Fibrinolysis
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 93
Incorrect
-
A patient is sent in by her GP with suspected ectopic pregnancy. Tubal ectopic pregnancies occur most commonly in which part of the uterine tube:
Your Answer: Fimbriae
Correct Answer: Ampulla
Explanation:Ectopic pregnancy most commonly occurs in the ampulla (70% of cases).
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 94
Correct
-
An ambulance transports a 37-year-old woman who is having a seizure. She is moved to resuscitation and given a benzodiazepine dose, which quickly ends the seizure. You later learn that she has epilepsy and is usually treated with carbamazepine to control her seizures.What is carbamazepine's main mechanism of action?
Your Answer: Sodium channel blocker
Explanation:Carbamazepine is primarily used to treat epilepsy, and it is effective for both focal and generalised seizures. It is not, however, effective in the treatment of absence or myoclonic seizures. It’s also commonly used to treat neuropathic pain, as well as a second-line treatment for bipolar disorder and as a supplement for acute alcohol withdrawal.Carbamazepine works as a sodium channel blocker that preferentially binds to voltage-gated sodium channels in their inactive state. This prevents an action potential from firing repeatedly and continuously.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 95
Incorrect
-
Regarding the extensor carpi ulnaris muscle, which of the following statements is true?
Your Answer: It lies within the anterior compartment of the forearm
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 96
Incorrect
-
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: Metronidazole
Correct 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 97
Incorrect
-
Antidiuretic hormone (ADH) levels are found to be increased in a young lady with unexplained hyponatraemia.Which of the following is a result of the release of ADH?
Your Answer: Small volumes of dilute urine
Correct Answer: Small volumes of concentrated urine
Explanation:ADH, or antidiuretic hormone, is a hormone that regulates water and electrolyte balance. It is released in response to a variety of events, the most important of which are higher plasma osmolality or lower blood pressure. ADH increases plasma volume and blood pressure via acting on the kidneys and peripheral vasculature.ADH causes extensive vasoconstriction by acting on peripheral V1 Receptors.ADH binds to B2 Receptors in the terminal distal convoluted tubule and collecting duct of the kidney, increasing transcription and aquaporin insertion in the cells that line the lumen. Aquaporins are water channels that allow water to pass through the tubule and into the interstitial fluid via osmosis, lowering urine losses.The permeability of the distal collecting duct (the section within the inner medulla) to urea is likewise increased by ADH. More urea travels out of the tubule and into the peritubular fluid, contributing to the counter current multiplier, which improves the Loop of Henle’s concentrating power.Overall, there is enhanced urea and water reabsorption in the presence of ADH, resulting in modest amounts of concentrated urine. There is minimal urea and water reabsorption in the absence of ADH, resulting in huge amounts of dilute urine.
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 98
Correct
-
Dexamethasone would be most useful for which of the following conditions:
Your Answer: Raised intracranial pressure secondary to malignancy
Explanation:Dexamethasone has a very high glucocorticoid activity in conjunction with insignificant mineralocorticoid activity. This makes it particularly suitable for high-dose therapy in conditions where fluid retention would be a disadvantage such as in the management of raised intracranial pressure or cerebral oedema secondary to malignancy. Dexamethasone also has a long duration of action and this, coupled with its lack of mineralocorticoid action makes it particularly suitable for suppression of corticotropin secretion in congenital adrenal hyperplasia. In most individuals a single dose of dexamethasone at night, is sufficient to inhibit corticotropin secretion for 24 hours. This is the basis of the ‘overnight dexamethasone suppression test’ for diagnosing Cushing’s syndrome.
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This question is part of the following fields:
- Endocrine
- Pharmacology
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Question 99
Incorrect
-
Which of the following microbes adheres to the genital mucosa using fimbriae:
Your Answer: Treponema pallidum
Correct Answer: Neisseria gonorrhoeae
Explanation:Infection of the genital mucosa by Neisseria gonorrhoeae involves attachment to and invasion of epithelial cells. Initial adherence of gonococci to columnar epithelial cells is mediated by type IV pili assembled from pilin subunit PilE proteins and pilus tip-associated PilC proteins, it then invades the epithelial layer, triggering a local acute inflammatory response.
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This question is part of the following fields:
- Microbiology
- Principles
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Question 100
Correct
-
Where: Capillary hydrostatic pressure is (P c) Hydrostatic pressure in the interstices is (P I )Plasma oncotic pressure is (π p) Interstitial oncotic pressure is (π i)Which of the following formulas best represents fluid flow at the capillary bed?
Your Answer: Volume / min = (P c - P i ) - (π p - π i )
Explanation:Starling’s equation for fluid filtration describes fluid flow at the capillary bed.Filtration forces (capillary hydrostatic pressure and interstitial oncotic pressure) stimulate fluid movement out of the capillary, while resorption forces promote fluid movement into the capillary (interstitial hydrostatic pressure and plasma oncotic pressure). Although the forces fluctuate along the length of the capillary bed, overall filtration is achieved.At the capillary bed, there is fluid movement.The reflection coefficient (σ), the surface area accessible (S), and the hydraulic conductance of the wall (Lp) are frequently used to account for the endothelium’s semi-permeability, yielding:Volume / min = LpS [(Pc- Pi) –  σ(Ï€p– Ï€i)]Volume /min = (Pc-Pi) – (Ï€p–πi) describes the fluid circulation at the capillaries.Where:Pc= capillary hydrostatic pressurePi= interstitial hydrostatic pressureÏ€p= plasma oncotic pressureÏ€i= interstitial oncotic pressure
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This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
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Question 101
Incorrect
-
A 34-year-old man presents with loss of vision in his left eye due to an episode of optic neuritis. Upon history taking, it was noted that he has a history of multiple sclerosis. Which of the following anatomical points in the visual pathway has the lesion occurred?
Your Answer: Upper optic radiation
Correct Answer: Optic nerve
Explanation:A lesion in the optic nerve causes ipsilateral monocular visual loss.Optic neuritis is an inflammatory demyelination of the optic nerve that is highly associated with multiple sclerosis. The two most common symptoms of optic neuritis are vision loss and eye pain.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 102
Incorrect
-
Which of the following nerves is responsible for the symptoms of a patient who presented with ophthalmic herpes zoster and a few vesicles on the nose?
Your Answer: Facial nerve
Correct Answer: Trigeminal nerve
Explanation:Hutchinson sign relates to involvement of the tip of the nose from facial herpes zoster. It implies involvement of the external nasal branch of the nasociliary nerve which is a branch of the ophthalmic division of the trigeminal nerve. The nasociliary branch of the trigeminal nerve innervates the apex and lateral aspect of the nose, as well as the cornea. Therefore, lesions on the side or tip of the nose should raise suspicion of ocular involvement.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 103
Incorrect
-
Loop diuretics primarily act on which Na+ transporter?
Your Answer: Na + /Cl - symporter
Correct Answer: Na + /K + /2Cl - symporter
Explanation:The most potent diuretics are loop diuretics e.g. furosemide. They work by inhibiting the Na+/K+/2Cl-symporter in the thick ascending limb of the loop of Henle, which inhibits sodium, potassium, and chloride reabsorption. As a result, there is diuresis with loss of these electrolytes. There is a reduction in transcellular voltage difference, paracellular calcium and magnesium reabsorption.The medullary interstitium becomes more concentrated by salt reabsorption in the ascending limb. Loop diuretics block this process and reduce the ability of the kidney to concentrate urine. In the collecting duct, there is increased sodium delivery to the principal cells, which increases potassium secretion in return for sodium reabsorption.
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This question is part of the following fields:
- Physiology
- Renal
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Question 104
Incorrect
-
Which of the following corticosteroids has the most potent mineralocorticoid effect:
Your Answer: Betamethasone
Correct Answer: Fludrocortisone
Explanation:Fludrocortisone has the most potent mineralocorticosteroid activity, making it ideal for mineralocorticoid replacement in adrenal insufficiency.
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This question is part of the following fields:
- Endocrine
- Pharmacology
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Question 105
Incorrect
-
A type II error occurs when:
Your Answer: The alternative hypothesis is accepted when it is false.
Correct Answer: The null hypothesis is accepted when it is false.
Explanation:A type II error occurs when the null hypothesis is wrongly accepted when it is actually false and we conclude that there is no evidence of a difference in effect when one really exists (a false negative result).
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 106
Correct
-
A 25-year old male is brought to the emergency room after a traffic accident. Upon examination, there was tenderness and erythema on the right acromioclavicular joint, with notable step deformity. On radiographic imaging, there is a superior elevation of the clavicle, a twice than normal coracoclavicular distance, and absence of fracture.Which of the following structure/s is/are likely to have ruptured?
Your Answer: Acromioclavicular ligament, coracoclavicular ligament and joint capsule
Explanation:Acromioclavicular joint injuries account for more than forty percent of all shoulder injuries. Mild injuries are not associated with any significant morbidity, but severe injuries can lead to significant loss of strength and function of the shoulder. Acromioclavicular injuries may be associated with a fractured clavicle, impingement syndromes, and more rarely neurovascular insults.The AC joint is a diarthrodial joint defined by the lateral process of the clavicle articulating with the acromion process as it projects anteriorly off the scapula. The joint is primarily stabilized by the acromioclavicular ligament, which is composed of an anterior, posterior, inferior, and superior component. Of note, the superior portion of the AC ligament is the most important component for the stability of the AC joint. Supporting structures include two coracoclavicular ligaments (trapezoid and conoid ligaments), which provide vertical stability, as well as the coracoacromial ligament.Patients with an AC joint injury typically present with anterosuperior shoulder pain and will describe a mechanism of injury of blunt trauma to the abducted shoulder or landing on an outstretched arm, suggestive of this type of injury. They may describe pain radiating to the neck or shoulder, which is often worse with movement or when they try to sleep on the affected shoulder. On examination, the clinician may observe swelling, bruising, or a deformity of the AC joint, depending on the degree of injury. The patient will be tender at that location. They may have a restriction in the active and passive range of motion secondary to pain. Piano key sign may be seen, with an elevation of the clavicle that rebounds after inferior compression.Standard X-rays are adequate to make a diagnosis of acromioclavicular joint injury and should be used to evaluate for other causes of traumatic shoulder pain.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 107
Incorrect
-
A patient presents with a rash for dermatological examination. A large area of purplish discolouration of the skin that measures 2 cm in diameter and does not blanch when pressure is applied is seen .What is the best description of this rash that you have found on examination?
Your Answer: Petechiae
Correct Answer: Ecchymoses
Explanation:Ecchymosis are discolouration of the skin or mucous membranes caused by extravasation of blood. They are usually red or purple in colour and measure greater than 1 cm in diameter and do not blanch on applying pressure. A macule is a flat, well circumscribed area of discoloured skin less than 1 cm in diameter with no changes in the thickness or texture of the skin. Petechiae are discolouration of the skin measuring less than 3 mm in diameterPurpura are discolouration of the skin measuring between 0.3 cm and 1 cm in diameter.Erythema is redness of the skin or mucous membranes caused by hyperaemia of superficial capillaries caused by skin injury, infection or inflammation. Erythema blanches when pressure is applied whereas ecchymosis, purpura and petechiae do not.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 108
Incorrect
-
What is the approximate lifespan of the mature erythrocyte:
Your Answer: 90 days
Correct Answer: 120 days
Explanation:Erythrocytes have a normal lifespan of about 120 days. Mature erythrocytes are biconcave discs with no nucleus, ribosomes or mitochondria but with the ability to generate energy as ATP by the anaerobic glycolytic pathway. The red cell membrane consists of a bipolar lipid layer with a membrane skeleton of penetrating and integral proteins anchoring carbohydrate surface antigens. The shape and flexibility of red cells allows them to deform easily and pass through capillaries.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 109
Incorrect
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What is the main mechanism of action of metoclopramide:
Your Answer: Serotonin-5HT3 antagonist
Correct Answer: Dopamine antagonist
Explanation:Metoclopramide is a dopamine-receptor antagonist. Blockade of inhibitory dopamine receptors in the GI tract may allow stimulatory actions of ACh at muscarinic synapses to predominate. Metoclopramide also blocks dopamine D2-receptors within the chemoreceptor trigger zone (CTZ). At high doses, it is also thought to have some 5-HT3antagonist activity.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 110
Incorrect
-
Which of the following is NOT a common side effect of adenosine:
Your Answer: Dyspnoea
Correct Answer: Yellow vision
Explanation:Common side effects of adenosine include:ApprehensionDizziness, flushing, headache, nausea, dyspnoeaAngina (discontinue)AV block, sinus pause and arrhythmia (discontinue if asystole or severe bradycardia occur)
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 111
Incorrect
-
A man presents to the emergency department with a hand laceration that has damaged the opponens digiti minimi muscle.All of the following statements regarding the opponens digiti minimi muscle is considered correct, except:
Your Answer: It is a triangular-shaped muscle in the hand
Correct Answer: It is innervated by the superficial branch of the ulnar nerve
Explanation:Opponens digiti minimi (ODM) is an intrinsic muscle of the hand. It’s a triangular muscle that extends between the hamate bone (carpal bone) and the 5th metacarpal bone. It forms the hypothenar muscle group together with the abductor digiti minimi and flexor digiti minimi brevis, based on the medial side of the palm (hypothenar eminence). These muscles act together in moving the little finger. The opponens digiti minimi is responsible for flexion, lateral rotation and opposition of the little finger.Its origin is the hook of hamate and flexor retinaculum. It inserts into the medial border of 5th metacarpal bone. It is innervated by the deep branch of the ulnar nerve, which stems from the brachial plexus (C8, T1 spinal nerves).Its blood supply is by the deep palmar branch of ulnar artery and deep palmar arch, which is the terminal branch of the radial artery.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 112
Incorrect
-
A patient complains of stomach ache. You see a midline scar in the epigastric area when you examine the abdomen. Upon further interrogation, the patient reveals that she had a subtotal gastrectomy for recurring stomach ulcers several years ago. The stomach mucosa secretes a variety of vital compounds, and her ability to secrete some of these molecules has been harmed as a result of his surgery.The stomach G-cells are responsible for which of the following?Â
Your Answer: Digestion of proteins
Correct Answer: Secretion of gastrin
Explanation:G-cells are a type of cell found in the stomach’s pyloric antrum, duodenum, and pancreas. The secretion of the peptide hormone gastrin is their major function.The table below summarizes the many cell types found in the stomach, as well as the substances secreted by each cell type and the function of the secretion:Cell type/ Substance secreted/ Function of secretionParietal cells/ Hydrochloric acid/ Kills microbes and activates pepsinogenParietal cells/ Intrinsic factor/Binds to vitamin B12 and facilitates its absorptionChief cells/ Pepsinogen/ Protein digestionChief cells/ Gastric lipase/ Fat digestionG-cells/ Gastrin/ Stimulates gastric acid secretionEnterochromaffin-like cells (ECL cells) /Histamine/ Stimulates gastric acid secretionMucous-neck cells/ Mucous and bicarbonate/ Protects stomach epithelium from acidD-cells/ Somatostatin/ Inhibits gastric acid secretion
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This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 113
Incorrect
-
A 22-year-old with a history of brittle asthma is brought to the ED by her partner. She is wheezing and very short of breath and her condition is deteriorating rapidly. Following a series of nebulisations, hydrocortisone and IV magnesium sulphate, she is taken to resus and the intensive care team is called to review her. She is severely hypoxic and confused and a decision is made to intubate her.Which of these drugs is ideal as an induction agent in this patient?
Your Answer: Diazepam
Correct Answer: Ketamine
Explanation:Only about 2% of asthma attacks requires intubation and most severe cases are managed with non-invasive ventilation techniques.Though life-saving in the crashing asthmatic, intubation in asthmatic patients is associated with significant morbidity and mortality and is risky. Indications for intubation in asthmatic patients include:Severe hypoxiaAltered mental stateRespiratory or cardiac arrestFailure to respond to medicationsKetamine (1-2 mg/kg) is the preferred induction agent. It has bronchodilatory properties and does not cause hypotension. Propofol poses a risk of hypotension but can also be used.
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This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 114
Incorrect
-
Regarding drug interactions with erythromycin, which of the following statements is INCORRECT:
Your Answer: Erythromycin increases plasma levels of carbamazepine.
Correct Answer: Erythromycin decreases plasma levels of warfarin.
Explanation:Erythromycin and clarithromycin inhibit cytochrome P450-mediated metabolism of warfarin, phenytoin and carbamazepine and may lead to accumulation of these drugs. There is an increased risk of myopathy (due to cytochrome P450 enzyme CYP3A4 inhibition) if erythromycin or clarithromycin is taken with atorvastatin or simvastatin. Erythromycin increases plasma concentrations of theophylline, and theophylline may also reduce absorption of oral erythromycin. All macrolides can prolong the QT-interval and concomitant use of drugs that prolong the QT interval is not recommended.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 115
Incorrect
-
Gastrin release from antral G-cells is stimulated by all but which one of the following:
Your Answer: Small peptides and amino acids in chyme
Correct Answer: Secretin
Explanation:Gastrin secretion is stimulated by: The presence of small peptides and amino acids in chymeGastric distensionVagal stimulation directly via acetylcholine and indirectly via gastrin-releasing peptide (GRP)Raised gastric pH
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 116
Incorrect
-
Regarding the power of a study, which of the following statements is INCORRECT:
Your Answer: A study power set at 80% accepts the likelihood of a 1 in 5 chance of missing a statistically significant difference where one exists.
Correct 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 117
Incorrect
-
A 35 year old man presents with a deep laceration to the proximal part of the forearm. On further assessment, the patient is unable to flex the metacarpophalangeal joints and interphalangeal joints of the index, middle finger and the thumb. The ring and little fingers are intact but there is weakness at the proximal interphalangeal joint.There is also loss of sensation over the lateral palm and the palmar surface of the lateral three and a half fingers. Which of these nerve(s) has most likely been affected?
Your Answer: Ulnar nerve
Correct Answer: Median nerve
Explanation:A median nerve injury affecting the extrinsic and intrinsic muscles of the hand will present with:Loss of sensation to the lateral palm and the lateral three and a half fingers.Weakness of flexion at the metacarpophalangeal joints of the index and middle finger. This is because of paralysis of the lateral two lumbricals. Weakness of flexion of the proximal interphalangeal joints of all four fingers due to paralysis of the flexor digitorum superficialisWeakness of flexion at the distal interphalangeal joints of the index and middle finger following paralysis of the lateral half of the flexor digitorum profundus.Weakness of thumb flexion, abduction and opposition due to paralysis of the flexor pollicis longus and thenar muscles
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 118
Correct
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You examine a 43-year-old woman who was referred to you by a friend. She suffers from a variety of medical conditions and takes a variety of medications, including amitriptyline.Which of the following is NOT a contraindication to amitriptyline treatment?
Your Answer: Breastfeeding
Explanation:Amitriptyline is a tricyclic antidepressant (TCA) that is most commonly used to treat depression, but it can also be used to treat anxiety disorders, chronic pain, and attention deficit hyperactivity disorder (ADHD). It inhibits reuptake, raising serotonin and noradrenaline levels while also inhibiting acetylcholine action.TCAs have a number of drawbacks, including:Acute PorphyriaArrhythmiasDuring bipolar disorder’s manic phaseHeart blockAfter a myocardial infarction, there is an immediate recovery period.TCA levels in breast milk are too low to be harmful, and use can be continued while breastfeeding.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 119
Incorrect
-
A 49-year-old woman has a history of hypertension and persistent hypokalaemia and is diagnosed with hyperaldosteronism.Which of these is the commonest cause of hyperaldosteronism?
Your Answer: Diuretic usage
Correct Answer: Adrenal adenoma
Explanation:When there are excessive circulating levels of aldosterone, hyperaldosteronism occurs. There are two main types of hyperaldosteronism:Primary hyperaldosteronism (,95% of cases)Secondary hyperaldosteronism (,5% of cases)Primary causes of hyperaldosteronism include:Adrenal adenoma (Conn’s syndrome) Adrenal hyperplasiaAdrenal cancerFamilial aldosteronismSecondary causes of hyperaldosteronism include:DrugsObstructive renal artery disease Renal vasoconstrictionOedematous disorders syndrome Adrenal adenoma is the commonest cause of hyperaldosteronism (seen in ,80% of all cases).
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 120
Correct
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A 26-year-old female cuts her hand on a knife while preparing dinner but the bleeding stops within a few minutes. Which one of the following cells will be among the first to be present at the wound site to be involved in haemostasis?
Your Answer: Platelets
Explanation:Platelets are the first cells to be attracted to the wound site due to the release of the Von Willebrand factor from the damaged endothelium. Platelets, in turn, release cytokines such as platelet-derived growth factor, which will attract other inflammatory cells to the wound site.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 121
Correct
-
Regarding bile acids, which of the following statements is INCORRECT:
Your Answer: The main primary bile acids are deoxycholic acid and lithocholic acid.
Explanation:Bile acids have a hydrophobic and a hydrophilic end and in aqueous solution, bile salts orient themselves around droplets of lipid forming micelles to keep the lipid droplets dispersed. The principal primary bile acids are cholic acid and chenodeoxycholic acid. They are made more soluble by conjugation with taurine or glycine in the liver. Of the bile acids excreted into the intestine, about 95% are reabsorbed into the portal circulation by active transport mechanisms in the distal ileum and recycled by the liver.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 122
Incorrect
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You see a 63-year-old man with a history of melaena and epigastric discomfort. For a few months, he's been taking aspirin.Which of the following statements about aspirin's mechanism of action is correct?
Your Answer: COX-1 inhibition is primarily responsible for its anti-inflammatory effects
Correct Answer: It inhibits both COX-1 and COX-2 at medium to high doses (500-5000 mg per day)
Explanation:Aspirin inhibits cyclo-oxygenase irreversibly by covalently acetylating the cyclo-oxygenase active site in both COX-1 and COX-2. The production of prostaglandin and thromboxane is reduced as a result. As a result, platelet activation and aggregation are reduced. A single dose of aspirin has a half-life of 7-10 days, which is the time it takes for the bone marrow to produce new platelets.Aspirin only inhibits COX-1, the enzyme that produces thromboxane A2, at low doses (75 mg per day), and thus has a primarily anti-thrombotic effect.Aspirin inhibits both COX-1 and COX-2 at medium to high doses (500-5000 mg per day). COX-2 is involved in the production of prostaglandins, so it has an anti-inflammatory effect at these concentrations.Aspirin, when used as an antipyretic for a viral illness in children, can cause Reye’s syndrome. Reye’s syndrome is a potentially fatal liver disease that causes encephalopathy and liver failure.The inability of aspirin to reduce platelet production of thromboxane A2, and thus platelet activation and aggregation, is known as aspirin resistance. Although the exact frequency and mechanism of aspirin resistance are unknown, it is thought to affect about 1% of users. Women are more likely than men to experience this phenomenon.According to new research, taking aspirin on a regular basis lowers the risk of colorectal cancer. It may also protect against cancers of the breast, bladder, prostate, and lungs.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 123
Correct
-
Which of the following statements regarding forest plots is true? Select ONE answer only.Which of the following statements regarding forest plots is true? Select ONE answer only.
Your Answer: Larger studies are associated with smaller horizontal lines
Explanation:Forest plots are graphical displays designed to illustrate the relative strength of treatment effects in multiple individual studies addressing the same question.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 124
Incorrect
-
Flumazenil is a reversal agent for which of the following groups of drugs:
Your Answer: Depolarising muscle relaxants.
Correct Answer: Benzodiazepines
Explanation:Flumazenil is a benzodiazepine antagonist used for the reversal of the sedative effects of benzodiazepines after anaesthesia, sedation and similar procedures.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 125
Incorrect
-
A fracture on which of the following structures is associated with a posterior elbow dislocation?
Your Answer: Olecranon
Correct Answer: Radial head
Explanation:Fracture dislocations of the elbow appear extremely complex, and identification of the basic injury patterns can facilitate management. The simplest pattern of elbow fracture dislocation is posterior dislocation of the elbow with fracture of the radial head. Addition of a coronoid fracture, no matter how small, to elbow dislocation and radial head fracture is called the terrible triad of the elbow.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 126
Incorrect
-
Which of the following is NOT a function of antibodies:
Your Answer: Stimulate degranulation of mast cells
Correct Answer: Act as antigen receptors on T lymphocytes
Explanation:Antibodies: Neutralise toxins and prevent attachment of pathogensTarget, opsonise or agglutinate (clump together) antigens for phagocytosisActivate the complement cascade (leading to lysis or opsonisation of the pathogen)Act as antigen receptors on B lymphocytesActivate antibody-dependent cell-mediated cytotoxicity by natural killer (NK) cells or T cytotoxic cellsProvide mucosal immunity (IgA-mediated)Stimulate degranulation of mast cells (IgE and IgG mediated)Provide passive immunity to the newborn (through transplacental passage of IgG and secretion of IgA in breast milk)
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 127
Incorrect
-
A patient was diagnosed with Erb's palsy as a result of a brachial plexus injury sustained in a car accident and, as a result, suffers from left arm paralysis. The following muscles are affected by the injury, except
Your Answer: Supraspinatus
Correct Answer: Trapezius
Explanation:Damage to the C5 and C6 nerve roots causes Erb’s palsy. The spinal accessory nerve (CN XI) innervates the trapezius muscle, thus you would not expect this muscle to be impacted. The trapezius is a muscle that runs from the base of the neck across the shoulders and into the centre of the back.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 128
Incorrect
-
Carbon dioxide is transported in the blood approximately:
Your Answer: 60% as bicarbonate ions, 20% as carbamino compounds and 20% dissolved in plasma
Correct Answer: 60% as bicarbonate ions, 30% as carbamino compounds and 10% dissolved in plasma.
Explanation:Carbon dioxide is transported in the blood from tissues to the lungs in three ways as bicarbonate ions (60%), as carbamino compounds with proteins (30%) or simply dissolved in plasma (10%).
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 129
Incorrect
-
Regarding atracurium, which of the following statements is CORRECT:
Your Answer: Atracurium should be avoided in hepatic impairment.
Correct Answer: Effects such as flushing, tachycardia and hypotension can occur due to significant histamine release.
Explanation:Cardiovascular effects such as flushing, tachycardia, hypotension and bronchospasm are associated with significant histamine release; histamine release can be minimised by administering slowly or in divided doses over at least 1 minute. Atracurium undergoes non-enzymatic metabolism which is independent of liver and kidney function, thus allowing its use in patients with hepatic or renal impairment. Atracurium has no sedative or analgesic effects. All non-depolarising drugs should be used with care in patients suspected to be suffering with myasthenia gravis or myasthenic syndrome, as patients with these conditions are extremely sensitive to their effects and may require a reduction in dose.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 130
Incorrect
-
A 42-year-old woman presents with face swelling prominently affecting her upper lip and hands. She has previously been diagnosed with hereditary angioedema.Which of these is the most appropriate management option for this acute attack?
Your Answer: C1 esterase infusion
Correct Answer: Fresh frozen plasma
Explanation:Hereditary angioedema is inherited as an autosomal dominant disorder and is caused by deficiency of C1 esterase inhibitor, a protein that forms part of the complement system.Attacks can be precipitated by stress and minor surgical procedures. Clinical features of hereditary angioedema include oedema of the skin and mucous membranes commonly affecting the face, tongue and extremities.Angioedema and anaphylaxis due to a deficiency of C1 esterase inhibitor are resistant to adrenaline, steroids and antihistamines. Treatment is with fresh frozen plasma or C1 esterase inhibitor concentrate, which contains C1 esterase inhibitor.Short-term prophylaxis for events that may precipitate angioedema attack is achieved with C1 esterase inhibitor or fresh frozen plasma infusions before the event while long-term prophylaxis can be achieved with antifibrinolytic drugs (tranexamic acid) or androgenic steroids.
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This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 131
Incorrect
-
While studying fluid homeostasis in the body, you encounter the term exudate. Exudate is a fluid that leaks out of the intravascular space due to changes in the permeability of the microcirculation secondary to inflammation. Which ONE of the following conditions would not be listed among the causes of an exudate?
Your Answer: Rheumatoid arthritis
Correct Answer: Myxoedema
Explanation:An exudate is an inflammatory fluid that leaks out of the intravascular space due to increased vascular permeability and intravascular pressure. It is mostly caused by local processes and can occur in the following conditions:1) Infection (e.g. pneumonia)2) Malignancy3) Pericarditis4) Collagen vascular diseases, e.g., Rheumatoid ArthritisMyxoedema is a state of severe hypothyroidism in which deposition of mucopolysaccharides occurs in the dermis. This causes a transudative effusion, typically in the pretibial region.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 132
Incorrect
-
A 68-year-old patient shows Low calcium levels and is on dialysis for chronic kidney disease.What percentage of total serum calcium is in the form of free or ionised Ca 2+?
Your Answer: 10%
Correct Answer: 50%
Explanation:Approximately half of total serum calcium is in the free or ionised Ca2+ state, 40% is attached to plasma proteins (mostly albumin), and the remaining 10% is in complexes with organic ions like citrate and phosphate. The ionized form is the only one that works.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 133
Correct
-
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 134
Incorrect
-
Regarding V/Q mismatch, which of the following statements is CORRECT:
Your Answer: The V/Q ratio in a normal, healthy lung is uniform throughout the lung.
Correct Answer: In a true shunt, increasing inspired oxygen has no effect on improving hypoxaemia.
Explanation:Both ventilation and perfusion increase towards the lung base, because of the effects of gravity, but the gravitational effects are greater on perfusion than ventilation and therefore there is a regional variation in V/Q ratio from lung apex (high V/Q) to lung base (low V/Q). In a pure shunt, there is normal perfusion but absent ventilation and the V/Q ratio = 0. In a true shunt increasing oxygen fraction has no effect because the oxygen-enriched air fails to reach the shunted blood. An increased A-a gradient is seen in V/Q mismatch.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 135
Incorrect
-
The big toe of a 59-year-old female is red, hot, and swollen. The patient is diagnosed with acute gout. You intend to start her on a nonsteroidal anti-inflammatory medicine (NSAID). Her husband was diagnosed with a peptic ulcer, and she is apprehensive about the potential adverse effects of NSAIDs.Which of the following NSAIDs has the lowest chance of causing side effects?Â
Your Answer: Diclofenac
Correct Answer: Ibuprofen
Explanation:Non-steroidal anti-inflammatory medications (NSAIDs) have slight differences in anti-inflammatory activity, but there is a lot of diversity in individual response and tolerance to these treatments. Approximately 60% of patients will respond to any NSAID; those who do not respond to one may well respond to another. Pain relief begins soon after the first dose, and a full analgesic effect should be achieved within a week, whereas an anti-inflammatory effect may take up to three weeks to achieve (or to be clinically assessable). If the desired results are not reached within these time frames, another NSAID should be attempted.By inhibiting the enzyme cyclo-oxygenase, NSAIDs limit the generation of prostaglandins. They differ in their selectivity for inhibiting various types of cyclo-oxygenase; selective inhibition of cyclo-oxygenase-2 is linked to reduced gastrointestinal discomfort. Susceptibility to gastrointestinal effects is influenced by a number of different parameters, and an NSAID should be chosen based on the frequency of side effects.Ibuprofen is an anti-inflammatory, analgesic, and antipyretic propionic acid derivative. Although it has fewer side effects than other non-selective NSAIDs, its anti-inflammatory properties are less effective. For rheumatoid arthritis, daily doses of 1.6 to 2.4 g are required, and it is contraindicated for illnesses characterized by inflammation, such as acute gout.Because it combines strong efficacy with a low incidence of adverse effects, Naproxen is one of the top choices. It is more likely to cause negative effects than ibuprofen.Similar to ibuprofen, ketoprofen and diclofenac have anti-inflammatory characteristics, however they have additional negative effects.Indomethacin has a similar or better effect to naproxen, however it comes with a lot of side effects, such as headaches, dizziness, and gastrointestinal problems.
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This question is part of the following fields:
- Musculoskeletal Pharmacology
- Pharmacology
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Question 136
Incorrect
-
Which of the following statements is correct with regards to Klebsiella spp?
Your Answer: They are obligate anaerobes.
Correct Answer: They are typically associated with nosocomial infection.
Explanation:Klebsiella is a type of bacteria commonly found in nature. In humans, the bacteria are often present in parts of the digestive tract and respiratory flora, where they do not generally cause problems. They are anaerobic Gram-negative rods. They are usually opportunistic pathogens which cause nosocomial infections, the most common ones being pneumonia and UTI.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 137
Incorrect
-
A 35-year-old man is feeling unwell following his return from a business trip. He is diagnosed with a vector transmitted disease.Which of these organisms is commonly spread by vector-borne transmission?
Your Answer: Vibrio cholerae
Correct Answer: Borrelia burgdorferi
Explanation:Borrelia burgdorferiis, primarily spread by ticks and lice, is a zoonotic, vector-borne organism that causes Lyme disease.Neisseria meningitidis and Bordetella pertussis are droplet borne infections (airborne particle > 5 µm)Vibrio cholerae and Ascaris lumbricoides are spread by the faeco-oral route
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 138
Incorrect
-
Regarding amoxicillin, which of the following statements is INCORRECT:
Your Answer: Amoxicillin absorption is not affected by the presence of food in the stomach.
Correct Answer: It is used first line for bacterial tonsillitis.
Explanation:Amoxicillin is a derivative of ampicillin and has a similar antibacterial spectrum. It is better absorbed than ampicillin when given orally, producing higher plasma and tissue concentrations; unlike ampicillin, absorption is not affected by the presence of food in the stomach. The adverse effects of amoxicillin are mainly gastrointestinal and mild and include nausea, vomiting and diarrhoea. Amoxicillin is used first line for low to moderate severity community acquired pneumonia, exacerbations of chronic bronchitis, for acute otitis media, for acute sinusitis, for oral infections/dental abscess, for Listeria meningitis (in combination with another antibiotic), for infective endocarditis (in combination with another antibiotic) and for H. Pylori eradication (in combination with metronidazole/clarithromycin and a PPI). Penicillin V is used first line for bacterial tonsillitis; amoxicillin should be avoided in blind treatment of a sore throat as there is a high risk of a rash if glandular fever is present.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 139
Correct
-
Fusidic acid is primarily indicated for infections caused by which of the following microorganisms:
Your Answer: Staphylococcal infections
Explanation:Fusidic acid is a narrow spectrum antibiotic used for staphylococcal infections, primarily topically for minor staphylococcal skin (impetigo) or eye infection. It is sometimes used orally for penicillin-resistant staphylococcal infection, including osteomyelitis or endocarditis, in combination with other antibacterials.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 140
Incorrect
-
A 22 year old male has been stabbed and is brought to the ED with a stab wound to his upper limb. On examination, the patient is unable to flex the distal interphalangeal joints of the ring and little finger. However, the proximal interphalangeal joint is intact. The most likely affected nerve is which of the following, and at which level is this occurring?
Your Answer: Median nerve at elbow
Correct Answer: Ulnar nerve at elbow
Explanation:The medial half of the flexor digitorum profundus is innervated by the ulnar nerve. Paralysis of this muscle results in loss of flexion at the distal interphalangeal joint of the ring and little finger. Flexion at the proximal interphalangeal joint is preserved as this is a function of the flexor digitorum superficialis which is innervated by the median nerve. The ulnar nerve is not correct as ulnar nerve injury at the wrist would not affect the long flexors, and the injury must have been more proximal.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 141
Incorrect
-
A 22-year-old student presents with a painful, red and itchy right eye. On examination, there is mild erythema of palpebral conjunctiva, and follicles are visible on eversion of the eyelid. Lid oedema is evident, and you can also see a few petechial subconjunctival haemorrhages. The eye appears watery, and there is no purulent discharge. He has recently recovered from a mild upper respiratory tract infection.Which of these is the most likely causative organism?
Your Answer: Respiratory syncytial virus
Correct Answer: Adenovirus
Explanation:The most frequent cause of red eye is conjunctivitis. It is caused by inflammation of the conjunctiva which can be infective or allergic and accounts for about 35% of all eye problems presenting to general practice.Viral conjunctivitis is commonly caused by adenoviruses and it is the most common infectious conjunctivitis.The common bacterial causes of conjunctivitis are Haemophilus influenzae, Streptococcus pneumoniae, and Staphylococcus aureus.The clinical features of infective conjunctivitis include:Acute onset of conjunctival erythemaFeeling ‘grittiness’, ‘foreign body’ or ‘burning’ sensation in the eye.Watering and discharge which may cause transient blurring of visionFeatures of viral conjunctivitis include: watery and non-purulent eye discharge, lid oedema, follicles present on eyelid eversion, petechial subconjunctival haemorrhages and pseudomembranes may be seen on the tarsal conjunctival surfaces.This patients features are consistent with a viral aetiology, and the most likely causative organism is adenovirus,
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 142
Incorrect
-
A patient who shows symptoms of infection and is admitted under supervision of the medical team. The organism which caused this, is a Gram-negative bacterium, according to the culture. A penicillin therapy is suggested by the microbiologist.Which of the penicillins listed below is the most effective against Gram-negative bacteria?Â
Your Answer: Phenoxymethylpenicillin
Correct Answer: Amoxicillin
Explanation:Amoxicillin and Ampicillin are more hydrophilic (broad-spectrum)Â penicillins than benzylpenicillin and phenoxymethylpenicillin. Because they may penetrate through gaps in the outer phospholipid membrane, they are effective against Gram-negative bacteria. Amoxicillin and Ampicillin are resistant to penicillinase-producing microbes.Community-acquired pneumonia, otitis media, sinusitis, oral infections, and urinary tract infections are among the most prevalent conditions for which they are prescribed. The normal adult oral dose of Amoxicillin is 500 mg three times/day, which can be increased to 1 g three times/day if necessary. Ampicillin is given to adults in doses of 0.5-1 g every 6 hours.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 143
Correct
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Which of the following is the most common cause of megaloblastic anaemia:
Your Answer: Vitamin B12 deficiency
Explanation:Megaloblastic anemia results from inhibition of DNA synthesis during red blood cell production. When DNA synthesis is impaired, the cell cycle cannot progress from the growth stage to the mitosis stage. This leads to continuing cell growth without division, which presents as macrocytosis, with an increase in mean corpuscular volume (MCV). The defect in red cell DNA synthesis is most often due to hypovitaminosis, specifically vitamin B12 deficiency or folate deficiency.Folate is an essential vitamin found in most foods, especially liver, green vegetables and yeast. The normal daily diet contains 200 – 250 μg, of which about 50% is absorbed. Daily adult requirements are about 100 μg. Absorption of folate is principally from the duodenum and jejunum. Stores of folate are normally only adequate for 4 months and so features of deficiency may be apparent after this time.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 144
Incorrect
-
Atrial natriuretic peptide (ANP) is primarily produced in response to:
Your Answer: A decrease in Na+ concentration
Correct Answer: An increase in intravascular fluid volume
Explanation:Atrial natriuretic peptide (ANP) is released from cardiac atrial muscle cells in response to atrial stretch caused by an increase in intravascular fluid volume and is also produced in collecting duct cells.Atrial natriuretic peptide acts to inhibit sodium reabsorption in the distal nephron.
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This question is part of the following fields:
- Physiology
- Renal
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Question 145
Correct
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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 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 146
Incorrect
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A 26-year-old man is involved in a motorcycle accident that results in an open fracture of his tibia and fibula. The nerve that innervates peroneus tertius is damaged as a consequence of his injuries.Peroneus tertius receives its innervation from which of the following nerves? Select ONE answer only.
Your Answer: Femoral nerve
Correct Answer: Deep peroneal nerve
Explanation:Peroneus brevis is innervated by the superficial peroneal nerve.Peroneus longus is innervated by the superficial peroneal nerve.Peroneus tertius is innervated by the deep peroneal nerve.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 147
Incorrect
-
You examine a 50-year-old female who has a swollen, painful right big toe. She has a history of gout, and this discomfort is identical to prior relapses, according to her. She is currently taking 200 mg of allopurinol per day and has been for the last year. This is her second round of acute gout within this time period. She has no prior medical history to speak of and does not take any other medications. She doesn't have any known drug allergies.Which of the following management options is the SINGLE MOST APPROPRIATE?Â
Your Answer: Switch the allopurinol to febuxostat
Correct Answer: Continue with the allopurinol and commence naproxen
Explanation:Allopurinol should not be started during an acute gout episode because it can both prolong and trigger another acute attack. Allopurinol should be continued in patients who are currently taking it, and acute attacks should be treated as usual with NSAIDs or colchicine, as needed.Non-steroidal anti-inflammatory medications (NSAIDs), such as naproxen, are the first-line treatment for acute gout attacks. Colchicine can be used in situations where NSAIDs are contraindicated, such as in patients with hypertension or those who have had a history of peptic ulcer disease. Because there is no reason for this patient to avoid NSAIDs, naproxen would be the medicine of choice from the list above.It would be reasonable to titrate up the allopurinol dose once the acute episode has subsided, targeting <6 mg/dl (<360 µmol/l) plasma urate levels .Febuxostat (Uloric) is a drug that can be used instead of allopurinol to treat persistent gout.
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This question is part of the following fields:
- Musculoskeletal Pharmacology
- Pharmacology
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Question 148
Correct
-
Regarding forest plots, which of the following is the purpose of this graph?
Your Answer: To graphically display the relative strength of multiple studies attempting to answer the same question
Explanation:The results of meta-analysis are often displayed graphically in a forest plot. A properly constructed forest plot is the most effective way to graphically display the relative strength of multiple studies attempting to answer the same question. A typical meta-analysis consists of three main objectives that include estimation of effect sizes from individual studies and a pooled summary estimate with their confidence intervals (CIs), heterogeneity among the studies, and any publication bias. The forest plot illustrates the first two of these objectives. Forest plots visualize the effect measure and CI of individual studies, which provide the raw data for the meta-analysis, as well the pooled-effect measure and CI. The individual studies also can be grouped in the forest plot by some of their characteristics for ease of interpretation such as by study size or year of publication. When comparing the outcomes between an intervention and a control group, dichotomous outcome variables are expressed as ratios (i.e. odds ratios, ORs or risk ratios, RRs), while for continuous outcomes, a weighted mean difference is reported.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 149
Incorrect
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A young male has presented to the Emergency Department with a sudden onset of severe palpitations, shortness of breath, and chest pain. A 12-lead ECG is recorded, and it shows a narrow complex tachycardia that points to a diagnosis of supraventricular tachycardia. Vagal manoeuvres are attempted but are unsuccessful in eliminating the arrhythmia. The next action plan is to use a drug to revert to sinus rhythm. Out of the following, which is the first-line treatment for supraventricular tachycardia?
Your Answer: Flecainide
Correct Answer: Adenosine
Explanation:Paroxysmal supraventricular tachycardia is an intermittent tachycardia (HR > 100 bpm) and has the following characteristics:1. Sudden onset/offset (Contrast with sinus tachycardia)2. Electrical activity originates above the ventricle (Contrast with ventricular tachycardia)3. Produces narrow QRS complex (<120ms) The most common cause of PSVT is Atrioventricular nodal re-entrant tachycardia (AVNRT), most common in young women with a mean age onset of 32 years old. There are recurrent episodes of palpitations, and most of the episodes spontaneously. Sometimes, some vagal manoeuvres are required:1. Valsalva manoeuvre2. immersing the face in ice-cold water3. carotid sinus massage.If PSVT keeps persisting or is causing severe symptoms, the treatment of choice is intravenous adenosine. The patient’s ECG should be continuously monitored throughout the treatment. The recommended doses in adults are as follows:- Initial dose of adenosine is 6 mg by rapid IV bolus- If unsuccessful, give another dose of adenosine 12 mg by rapid IV bolus- If unsuccessful, give a further dose of adenosine 12 mg by rapid IV bolusThe latest ALS guidelines advocate 18 mg for the third dose, whereas the BNF/NICE guidelines advocate 12 mg.If adenosine fails or is contraindicated, intravenous verapamil can be used as an alternative, but it should be avoided in patients recently treated with beta-blockers.Synchronized electrical cardioversion will be necessary with signs of hemodynamic instability or if drug treatment has failed to restore sinus rhythm.Recurrent episodes of paroxysmal supraventricular tachycardia can be treated by catheter ablation or prevented with drugs such as flecainide, sotalol, diltiazem, or verapamil.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 150
Incorrect
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Urine flow rate = 2 ml/minUrine concentration of creatinine = 18 mg/ml Plasma concentration of creatinine = 0.25 mg/ml What is the estimated glomerular filtration rate (eGFR)?
Your Answer: 40 ml/min
Correct Answer: 144 ml/min
Explanation:GFR can be estimated by:GFR = UCr x V / PCrWhere:UCr = urine concentration of creatininePCr = plasma concentration of creatinineV = rate of urine flowIn this case GFR = (18 x 2) / 0.25 = 144 ml/minNote: Creatinine is used to estimate GFR because it is an organic base naturally produced by muscle breakdown, it is freely filtered at the glomerulus, it is not reabsorbed from the nephron, it is not produced by the kidney, it is not toxic, and it doesn’t alter GFR.
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 151
Incorrect
-
Regarding the UK routine childhood immunisation schedule which of the following vaccines is NOT given at 12 months:
Your Answer: Meningococcal group C
Correct Answer: Polio
Explanation:At 12 months the following vaccines are given:Hib (4th dose) and Meningococcal group CPneumococcal (13 serotypes) (2nd dose)Measles, mumps and rubellaMeningococcal group B (3rd dose)
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This question is part of the following fields:
- Immunoglobulins And Vaccines
- Pharmacology
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Question 152
Correct
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Regarding hypernatraemia, which of the following statements is INCORRECT:
Your 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 153
Incorrect
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In all of the following conditions, lymphocytosis typically occurs except for:
Your Answer: Infectious mononucleosis
Correct 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 154
Incorrect
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Regarding fat digestion, which of the following statements is CORRECT:
Your Answer: Chylomicrons are formed in the rough endoplasmic reticulum of the enterocyte.
Correct Answer: Chylomicrons consist of a cholesterol and triglyceride core with a phospholipid coat studded with apolipoproteins.
Explanation:Dietary fat is chiefly composed of triglycerides. In the duodenum fat is emulsified by bile acids, a process where larger lipid droplets are broken down into much smaller droplets providing a greater surface area for enzymatic digestion. Once inside the epithelial cell, lipid is taken into the smooth endoplasmic reticulum where much of it is re esterified. Dietary and synthesised lipids are then incorporated into chylomicrons in the Golgi body, which are exocytosed from the basolateral membrane to enter lacteals. Chylomicrons consist mainly of triglyceride with small amounts of cholesterol and cholesteryl esters in the centre with a phospholipid coat studded with apolipoproteins. Fat-soluble are absorbed into enterocytes from micelles by simple diffusion together with the products of fat digestion.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 155
Incorrect
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Regarding Clostridium tetani, which of the following statements is CORRECT:
Your Answer: Infection is usually endogenous.
Correct Answer: Infection is predominantly derived from animal faeces and soil.
Explanation:Clostridium tetaniis a Gram positive, rod shaped, obligate anaerobic bacterium.The incubation period is quoted as anywhere between 4-21 days and can occur after several months but symptoms usually occur within the first 7 days after exposure.Approximately 80% of patients develop generalised tetanus. The commonest presenting feature of generalised tetanus is trismus (lockjaw), occurring in approximately 75% of affected individuals. Other clinical features include:Facial spasms (risus sardonicus)Opisthotonus (characteristic body shape during spasms)Neck stiffnessDysphagiaCalf and pectoral muscle rigidityFeverHypertensionTachycardiaSpasms can occur frequently and last for several minutes, they can continue to occur for up to 4 weeks. Current mortality rates are between 10 and 15%.Tetanic spasms are caused by the exotoxin tetanospasmin. The effects of tetanolysin are not fully understood but it is not believed to have clinical significance.Localised tetanus is a rare form of the disease, occurring in around 1% of affected individuals. Patients have persistent contraction of muscles in the same anatomic area as the injury. It may precede generalised tetanus.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 156
Incorrect
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A 62 year old man has sustained a penetrating injury to the submandibular triangle. On examination, his tongue is weak and when protruded deviates to the left. Which of the following nerves has most likely been injured:
Your Answer: Right glossopharyngeal nerve
Correct Answer: Left hypoglossal nerve
Explanation:Damage to the hypoglossal nerve results in weakness of the tongue, with deviation of the tongue towards the weak side on protrusion.
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This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
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Question 157
Incorrect
-
Continuous capillaries are typically found where in the body:
Your Answer: Endocrine glands
Correct Answer: Blood-brain barrier
Explanation:Continuous capillaries, found in the skin, lungs, muscles and CNS, are the most selective with low permeability, as junctions between the endothelial cells are very tight, restricting the flow of molecules with MW > 10,000.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 158
Correct
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An elderly man with chronic heart and lung disease develops Legionnaires' Disease. By what route was the infection most likely to have been acquired:
Your Answer: Inhalation of aerosolised contaminated water
Explanation:Legionella pneumophilais a Gram negative bacterium that is found in natural water supplies and in the soil, transmitted predominantly via inhalation of aerosols generated from contaminated water (direct person-to-person spread of infected patients does not occur). It is the cause of Legionnaires’ disease. Outbreaks of Legionnaires’ disease have been linked to poorly maintained air conditioning systems, whirlpool spas and hot tubs.The clinical features of the pneumonic form of Legionnaires’ disease include:Mild flu-like prodrome for 1-3 daysCough (usually non-productive and occurs in approximately 90%)Pleuritic chest painHaemoptysisHeadacheNausea, vomiting and diarrhoeaAnorexiaLegionella pneumophilainfections can be successfully treated with macrolide antibiotics, such as erythromycin, or quinolones, such as ciprofloxacin. Tetracyclines, such as doxycycline, can also be used.The syndrome of inappropriate antidiuretic hormone secretion (SIADH) can occur with Legionnaires’ disease and will result in hyponatraemia as is seen in this case.Legionella pneumophilainfections are resistant to amoxicillin but can be successfully treated with macrolide antibiotics, such as erythromycin, or quinolones, such as ciprofloxacin. Tetracyclines, such as doxycycline, can also be used. The majority of cases of Legionnaires’ disease are caused by Legionella pneumophila, however many other species of Legionella have been identified.Legionella longbeachae is another less commonly encountered species that has also been implicated in outbreaks. It is predominantly found in soil and potting compost, and has caused outbreaks of Pontiac fever, the non-respiratory and less severe variant of Legionnaires’ disease.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 159
Correct
-
A 20-year-old female presents with painful wrist following a fall while skating. X-rays shows fracture of the ulna.The initial phase of bone healing is?
Your Answer: Haematoma at the fracture site
Explanation:Haemorrhage occurs into the fracture site from the ruptured vessels in the bone marrow and those supplying the periosteum immediately after fracture. This hematoma formation is the first phase of bone healing.The 4 stages of bone healing are:Haematoma at the fracture site (provides a framework for healing)Callus formationLamellar bone formationRemodelling
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 160
Incorrect
-
A 6-year-old child presents with profuse watery diarrhoea and dehydration. Which of the following statements is considered correct regarding infective diarrhoea?
Your Answer: There is no vaccination available for rotavirus
Correct Answer: E.Coli can cause diarrhoea and renal failure
Explanation:E. coli may cause several different gastrointestinal syndromes. Based on virulence factors, clinical manifestation, epidemiology, and different O and H serotypes, there are five major categories of diarrheagenic E. coli, enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC), enteropathogenic E. coli (EPEC), enterohemorrhagic E. coli (EHEC), and enteroadherent, which includes diffusely adherent E. coli (DAEC) and enteroaggregative E. coli (EAEC). These five categories are sometimescollectively referred to as enterovirulent E. coli or diarrheagenic E. coli.Norwalk virus is part of the Caliciviridae family of viruses which are single-stranded RNA viruses and are the most common cause of infectious gastroenteritis in the US.Rotaviruses are the most common cause of viral gastroenteritisin infants and children. With the introduction in 2006 of a human-bovine rotavirus vaccine (RV5; RotaTeq, Merck), a delay in the onset of rotavirusseason was seen. RotaTeq is a series of three oral vaccines beginning at 6 to 12 weeks of age. A second vaccine, Rotarix (RV1; GlaxoSmithKline, Middlesex, England), was approved in June 2008.Cryptosporidium causes an illness characterized by abdominal cramping, watery diarrhoea, vomiting, fever, and anorexia. This organism is resistant to chlorine, so public swimming pools can be the source of an outbreak.G. lamblia has a worldwide distribution and has frequently been identified as the causative agent of outbreaks of gastroenteritis and traveller’s diarrhoea.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 161
Incorrect
-
A 62-year-old female complains of pain in her right upper quadrant. An abdominal ultrasound is conducted, and a big gallstone is discovered. The radiologist who performs the scan speaks with you about the physiology of the gallbladder and biliary tract.During a 24-hour period, how much bile does the gallbladder produce?
Your Answer: 1200-1500 ml
Correct Answer: 400-800 ml
Explanation:The gallbladder stores and concentrates bile, which is produced by the liver. In a 24-hour period, around 400 to 800 mL of bile is generated. The breakdown of fats into fatty acids, the removal of waste materials, and cholesterol homeostasis are all crucial functions of bile.Bile is created on a constant basis, however it is only necessary after a meal has been consumed. The elimination of water and ions concentrates bile in the gallbladder, which is subsequently stored for later use. Food induces the release of the hormone cholecystokinin from the duodenum, the contraction of the gallbladder, and the relaxation of the sphincter of Oddi. The bile then enters the duodenum.Bile acids have a hydrophobic and hydrophilic area, making them amphipathic. Bile acids’ amphipathic nature allows them to perform the following crucial functions:Emulsification of lipid aggregates increases the surface area of fat and makes it easier for lipases to digest it.Lipid solubilization and transport: solubilizes lipids by creating micelles, which are lipid clumps that float in water.
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This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 162
Incorrect
-
The muscles of the soft palate (other than the tensor veli palatini) are innervated by which of the following nerves:
Your Answer: Glossopharyngeal nerve
Correct Answer: Vagus nerve
Explanation:All of the muscles of the soft palate are innervated by the vagus nerve (from the pharyngeal plexus), except for the tensor veli palatini, which is innervated by a branch of the mandibular nerve.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 163
Incorrect
-
Arterial baroreceptors are located primarily in which of the following:
Your Answer: Internal jugular vein
Correct Answer: Carotid sinus and aortic arch
Explanation:Arterial baroreceptors are located in the carotid sinus and aortic arch, and detect the mean arterial pressure (MAP). A decrease in MAP (such as in postural hypotension, or haemorrhage) reduces arterial stretch and decreases baroreceptor activity, resulting in decreased firing in afferent nerves travelling via the glossopharyngeal nerve (carotid sinus) and vagus nerve (aortic arch) to the medulla where the activity of the autonomic nervous system is coordinated. Sympathetic nerve activity consequently increases, causing an increase in heart rate and cardiac contractility, peripheral vasoconstriction with an increase in TPR, and venoconstriction with an increase in CVP and thus an increase in cardiac output and blood pressure. Parasympathetic activity (vagal tone) decreases, contributing to the rise in heart rate.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 164
Incorrect
-
Regarding cellular respiration, which of the following statements is CORRECT:
Your Answer: Cellular respiration is the process by which cells obtain energy in the form of AMP.
Correct Answer: When fats are used as the primary energy source, an excess of acetyl-CoA is produced.
Explanation:Cellular respiration is the process by which cells obtain energy in the form of adenosine triphosphate (ATP). ATP transfers chemical energy from the energy rich substances in the cell to the cell’s energy requiring reactions e.g. active transport, DNA replication and muscle contraction.Cellular respiration is essentially a three step process: 1) Glycolysis, 2)The Krebs cycle, 3)The electron transfer system.The main respiratory substrate used by cells is 6-carbon glucose. Fats and proteins can also be used as respiratory substrates. When fats are being used as the primary energy source, in the absence of glucose, an excess amount of acetyl-CoA is produced, and is converted into acetone and ketone bodies. This can occur in starvation, fasting or in diabetic ketoacidosis. Proteins are used as an energy source only if protein intake is very high, or if glucose and fat sources are depleted.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 165
Correct
-
A 54-year-old man who is acutely unwell has his blood sent for test and the results come back with a CRP of 115.Which of these statements about C-reactive protein is FALSE?
Your Answer: It is produced in the bone marrow
Explanation:C-reactive protein(CRP) is synthesized in the liver in response to increased interleukin-6 (IL-6) secretion by macrophages and T-cells. Some conditions that cause CRP levels to a rise include: bacterial infection, fungal infection, severe trauma, autoimmune disease, Organ tissue necrosis, malignancy and surgery.It is useful in the clinical setting as a marker of inflammatory activity and can be used to monitor infections. CRP levels start to rise 4-6 hours after an inflammatory trigger and reaches peak levels at 36-50 hours.In the absence of a disease process, the normal plasma concentration is less than 5 mg/l.CRP is useful for monitoring inflammatory conditions (e.g. rheumatoid arthritis and malignancy), can be used as a prognostic marker in acute pancreatitis, and serial measurement can be used to recognize the onset of nosocomial infections in the intensive care settling.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 166
Incorrect
-
Which of these cell types in the stomach releases pepsinogen?
Your Answer: Mucous-neck cells
Correct Answer: Chief cells
Explanation:The gastric chief cells in the stomach wall releases pepsinogen. Pepsinogen is a proenzyme. It mixes with hydrochloric acid in the stomach and is converted to pepsin. Pepsin breaks down proteins into peptides aiding protein digestion.
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This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 167
Incorrect
-
Pancreatic ductal alkaline fluid secretion is mainly stimulated by which of the following hormones:
Your Answer: Somatostatin
Correct 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 168
Incorrect
-
Which of the following is NOT a benefit of low molecular weight heparin (LMWH) over unfractionated heparin therapy:
Your Answer: It has a greater ability to inhibit factor Xa directly rather than inhibit antithrombin III.
Correct Answer: Its effects can be rapidly and completely reversed with protamine sulfate.
Explanation:Advantages of LMWHGreater ability to inhibit factor Xa directly, interacting less with platelets and so may have a lesser tendency to cause bleedingGreater bioavailability and longer half-life in plasma making once daily subcutaneous administration possibleMore predictable dose response avoiding the need for routine anticoagulant monitoringLower associated risk of heparin-induced thrombocytopenia or of osteoporosis
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 169
Correct
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One of your patients has been infected by an obligate pathogen and presents with features of this condition.Which of these is an example of an obligate pathogen?
Your Answer: Trepenoma pallidum
Explanation:Treponema pallidum is an obligate pathogen. Obligate pathogens are almost always associated with disease and usually cannot survive outside of the body for long periods of time. Examples include and HIV.Staphylococcus aureus and Bacteroides fragilis are conditional pathogens. These are pathogens that usually cause disease only if certain conditions are met.Pneumocystis jiroveci and Pseudomonas aeruginosa, are opportunistic pathogens. These are pathogens that can only cause disease in an immunocompromised host or under unusual circumstances.
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 170
Incorrect
-
The renin-angiotensin-aldosterone system (RAAS) controls blood pressure and fluid balance.Which of the following sites produces the most angiotensinogen?Â
Your Answer: The lungs
Correct Answer: The liver
Explanation:Angiotensinogen is an alpha-2-globulin generated predominantly by the liver and released into the blood. Renin, which cleaves the peptide link between the leucine and valine residues on angiotensinogen, converts it to angiotensin I.Angiotensinogen levels in the blood are raised by:Corticosteroid levels have risen.Thyroid hormone levels have risen.Oestrogen levels have risen.Angiotensin II levels have risen.
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 171
Incorrect
-
A 18 year old male presents to the GP with painless asymmetrical cervical lymphadenopathy. Histological examination of a biopsied lymph node demonstrates Reed-Sternberg cells. What is the most likely diagnosis:
Your Answer: Acute myeloid leukaemia
Correct Answer: Hodgkin lymphoma
Explanation:Hodgkin’s lymphoma is a malignant tumour of the lymphatic system that is characterised histologically by the presence of Reed-Sternberg cells (multinucleated giant cells). The annual incidence of Hodgkin’s lymphoma in the UK is approximately 3 per 100,000 per year. The peak incidence is in young adults aged 20-35, and there is a slight male predominance.The following are recognised risk factors for Hodgkin’s lymphoma:Male genderAge 20-35Positive family historyEpstein-Barr virus infectionImmunosuppression including HIV infectionProlonged use of human growth hormoneMost patients present with an enlarged, but otherwise asymptomatic lymph node. The most commonly affected lymph nodes are in the supraclavicular and lower cervical areas. Other common clinical features include shortness of breath and chest discomfort secondary to mediastinal mass. Mediastinal masses are sometimes discovered as incidental findings on routine chest X-rays. Approximately 30% of patients with Hodgkin’s lymphoma develop splenomegaly.‘B’ symptoms occur in approximately 25% of patients. The ‘B’ symptoms of Hodgkin’s lymphoma are:Fever (>38ºC)Night sweatsWeight loss (>10% over 6 months)Pain after alcohol consumption is a pathognomonic sign of Hodgkin’s lymphoma, it is, however, not a ‘B’ symptom. It is rare though, only occurring in 2-3% of patients with Hodgkin’s lymphoma.The Ann Arbour clinical staging is as follows:Stage I: one involved lymph node groupStage II two involved lymph node groups on one side of the diaphragmStage III: lymph node groups involved on both sides of the diaphragmStage IV: Involvement of extra-nodal tissues, such as the liver or bone marrowDiagnosis is made by lymph node biopsy, which should be taken from a sufficiently large specimen or excisional biopsy, as opposed to a fine needle biopsy. The Reed-Sternberg cell is the most useful diagnostic feature. This is a giant cell with twin mirror-image nuclei and prominent ‘owl’s eye’ nucleoli.The Reed-Sternberg cell of Hodgkin’s LymphomaHistological typing depends upon the other cells within the diseased tissue. Nodular sclerosing is the most common type of Hodgkin’s lymphoma. Lymphocyte-depleted and lymphocyte-predominant are rare subtypes.The majority of cases can be successfully treated, and unlike many other malignancies even if the first-line treatment fails, a cure can often be achieved with second-line therapies. Stage 1 Hodgkin’s lymphoma is usually treated with radiotherapy alone, but more advanced stages require combination chemotherapy. In localised disease treated with irradiation, there is a 5-year survival rate of greater than 80%. In disseminated disease treated with chemotherapy, the 5-year survival falls to around 50%. Overall, a 5-year survival of >70% should be achieved.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 172
Incorrect
-
A 26-year-old male presents to your clinic with the complaint of recurrent fevers over the past three months. On documentation of the fever, it is noted that the fever increases and decreases in a cyclical pattern over a 1-2 week period. After the appropriate investigations, a diagnosis of Pel-Ebstein fever is made. Which ONE of the following conditions is most likely to cause this patient's fever?
Your Answer: Glandular fever
Correct Answer: Hodgkin lymphoma
Explanation:The release of cytokines from Reed-Sternberg cells can cause fever in patients with Hodgkin lymphoma, which increases and decreases in a cyclical pattern of 1 to 2 weeks. This is called Pel-Ebstein or Ebstein-Cardarelli fever, specifically seen in Hodgkin lymphoma. The fever is always high grade and can reach 40 degrees or higher.Cyclical fever in other conditions is common but is not termed as Pel-Ebstein fever. This term is reserved only with Hodgkin lymphoma.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 173
Incorrect
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A 5-year-old girl is brought into the Paediatric ER for acute seizures. She has been convulsing for the past 18 minutes now and was already two doses of lorazepam in the ambulance. Now, you prepare a phenytoin infusion to abolish the seizures. According to the APLS algorithm, what dose of phenytoin is advised for a convulsing child at this stage?
Your Answer: 5 mg/kg over 20 minutes
Correct Answer: 20 mg/kg over 20 minutes
Explanation:Advanced paediatric life support (APLS) recommends phenytoin as the first choice for second-line anticonvulsant in a patient that continues to seize ten minutes after the second dose of the first-line anticonvulsant (benzodiazepine). (step 3 of the APLS algorithm)The recommended dose of phenytoin infusion is up at 20 mg/kg over 20 minutes. If the patient has already taken phenytoin as maintenance therapy or is allergic to phenytoin, then a phenobarbitone infusion should be set up at 20 mg/kg over 30-60 minutes.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 174
Incorrect
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A 27 year old woman presents to ED having sustained a deep laceration to the dorsum of her ring finger whilst cooking. Her proximal interphalangeal joint is fixed in flexion and the distal interphalangeal joint is hyperextended. Which of the following structures in the digit has most likely been injured:
Your Answer: Insertion of the flexor digitorum profundus
Correct Answer: Insertion of the central slip of the extensor tendon
Explanation:Damage to the central slip of the extensor digitorum tendon would result in loss of extension at the proximal interphalangeal joint resulting in a fixed flexion deformity of this joint, and hyperextension of the distal interphalangeal joint due to a loss of balancing forces. This is called the Boutonniere deformity.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 175
Incorrect
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A patient suffers a stab wound to the neck. The entry point of the blade is situated within the posterior triangle of the neck.Which of the following muscles is most likely to be involved? Select ONE answer only.
Your Answer: Trapezius
Correct Answer: Anterior scalene
Explanation:The anterior triangle is the triangular area of the neck found anteriorly to the sternocleidomastoid muscle. It is formed by the anterior border of sternocleidomastoid laterally, the median line of the neck medially and by the inferior border of the mandible superiorly. The apex of the anterior triangle extends towards the manubrium sterni. The anterior triangle contains:Muscles: thyrohyoid, sternothyroid, sternohyoid musclesOrgans: thyroid gland, parathyroid glands, larynx, trachea, esophagus, submandibular gland, caudal part of the parotid glandArteries: superior and inferior thyroid, common carotid, external carotid, internal carotid artery (and sinus), facial, submental, lingual arteriesVeins: anterior jugular veins, internal jugular, common facial, lingual, superior thyroid, middle thyroid veins, facial vein, submental vein, lingual veinsNerves: vagus nerve (CN X), hypoglossal nerve (CN XII), part of sympathetic trunk, mylohyoid nerveThe posterior triangle is a triangular area found posteriorly to the sternocleidomastoid muscle. It has three borders; anterior, posterior and inferior borders. The anterior border is the posterior margin of the sternocleidomastoid muscle. The posterior border is the anterior margin of the trapezius muscle, while the inferior border is the middle one-third of the clavicle. The investing layer of deep cervical fascia and integument forms the roof of the space, while the floor is covered with the prevertebral fascia along with levator scapulae, splenius capitis and the scalene muscles. The inferior belly of omohyoid subdivides the posterior triangle into a small supraclavicular, and a large occipital, triangle.Contents:Vessels: the third part of the subclavian artery, suprascapular and transverse cervical branches of the thyrocervical trunk, external jugular vein, lymph nodesNerves: accessory nerve (CN XI), the trunks of the brachial plexus, fibers of the cervical plexusOf the muscles listed in the options, only the anterior scalene is situated within the posterior triangle of the neck.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 176
Incorrect
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A patient is found to be anaemic. Which one of the following blood results would favour a diagnosis of anaemia of chronic disease rather than iron deficiency:
Your Answer: MCV < 80 fL
Correct Answer: Low total iron binding capacity (TIBC)
Explanation:Anaemia of chronic disease is one of the most common causes of normocytic anaemia. The anaemia is usually mild (Hb > 90 g/L) and non-progressive. Anaemia of chronic disease is usually associated with low serum iron, low transferrin saturation, and a low total iron binding capacity (TIBC) with normal or raised ferritin which differentiates it from iron deficiency anaemia.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 177
Incorrect
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Regarding the brachioradialis muscle, which of the following statements is true?
Your Answer: It assists with the extension of the forearm at the elbow
Correct Answer: It assists with supination of the forearm at the radioulnar joints
Explanation:Brachioradialis is a fusiform muscle located in the lateral part of the posterior forearm. Along with extensor carpi radialis brevis and extensor carpi radialis longus, it comprises the radial group of forearm muscles, which belong to the superficial layer of posterior forearm muscles. Although anatomically part of the posterior forearm muscles, which are known to be forearm extensors, brachioradialis’ fibre orientation enables it to rather flex the forearm, and aids in supination of the forearm at the radioulnar joint.The brachioradialis muscle originates from the upper two-thirds of the lateral supracondylar ridge of humerus and the anterior surface of the lateral intermuscular septum of the arm. It slides over the lateral surface of the elbow joint, entering the anterolateral cubital area. The muscle fibres course inferiorly down the radial part of the anterior forearm, forming a thick tendon in approximately the middle of the forearm. This tendon then traverses the remainder of the forearm, inserting near the wrist, just proximal to the styloid process of radius.Brachioradialis is innervated by the radial nerve (from the root values C5-C6) that stems from the posterior cord of the brachial plexus. Blood supply to the brachioradialis muscle comes from branches of the radial artery, radial recurrent artery and the radial collateral branch of the deep brachial artery.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 178
Incorrect
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Regarding skeletal muscle contraction, which of the following statements is CORRECT:
Your Answer: The force of contraction of a muscle is controlled by increasing the number of contracting muscle fibres.
Correct Answer: The force of contraction of a muscle can be controlled by increasing recruitment of motor units.
Explanation:Each motor unit contracts in an all or nothing fashion, i.e. if a motor unit is excited, it will stimulate all of its muscle fibres to contract. The force of contraction of a muscle is controlled by varying the motor unit recruitment (spatial summation), and by varying the firing rate of the motor units (temporal summation). During a gradual increase in contraction of a muscle, the first units start to discharge and increase their firing rate, and, as the force needs to increase, new units are recruited and, in turn, also increase their firing rate. For most motor units, the firing rate for a steady contraction is between 5 and 8 Hz. Because the unitary firing rates for each motor unit are different and not synchronised, the overall effect is a smooth force profile from the muscle. Increasing the firing rate of motor units is temporal summation where the tension developed by the first action potential has not completely decayed when the second action potential and twitch is grafted onto the first and so on. If the muscle fibres are stimulated repeatedly at a faster frequency, a sustained contraction results where it is not possible to detect individual twitches. This is called tetanus.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 179
Incorrect
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Clostridium difficile primarily causes which of the following infectious diseases:
Your Answer: Tetanus
Correct Answer: Pseudomembranous colitis
Explanation:Clostridium difficile causes pseudomembranous colitis, an acute inflammatory diarrhoeal disease and an important cause of morbidity and mortality in hospitals. Gas gangrene is primarily caused by Clostridium perfringens. Tetanus is caused by Clostridium tetani. Toxic shock syndrome may be caused by Staphylococcus aureus or Streptococcus pyogenes. Necrotising fasciitis is most commonly caused by Streptococcus pyogenes but has a multitude of causes.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 180
Incorrect
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A 23 year old student presents to ED with a widespread maculopapular rash. She recently had a sore throat and was started on a course of antibiotics. The most likely antibiotic that she was prescribed is:
Your Answer:
Correct Answer: Amoxicillin
Explanation:Maculopapular rashes are commonly seen with ampicillin and amoxicillin. However they are not usually related to true penicillin allergy. Very often, they occur in patients with glandular fever and so, broad-spectrum penicillins should not be used blindly, for management and treatment of a sore throat. There is also an increased risk of rash 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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SESSION STATS - PERFORMANCE PER SPECIALTY
