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Question 1
Correct
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Which of the following nerves has been damaged when a patient presents with a foot drop?
Your Answer: Common peroneal nerve
Explanation:The common peroneal nerve often referred to as the common fibular nerve, is a major nerve that innervates the lower extremity. It is one of the two major branches off the sciatic nerve and receives fibres from the posterior divisions of L4 through S2 nerve roots. The common peroneal nerve separates from the sciatic nerve in the distal posterior thigh proximal to the popliteal fossa. After branching off of the sciatic nerve, it continues down the thigh, running posteroinferior to the biceps femoris muscle, and crosses laterally to the head of the lateral gastrocnemius muscle through the posterior intermuscular septum. The nerve then curves around the fibular neck before dividing into two branches, the superficial peroneal nerve (SPN) and the deep peroneal nerve (DPN). The common peroneal nerve does not have any motor innervation before dividing; however, it provides sensory innervation to the lateral leg via the lateral sural nerve.
The superficial peroneal nerve innervates the lateral compartment of the leg, and the deep peroneal nerve innervates the anterior compartment of the leg and the dorsum of the foot. These two nerves are essential in the eversion of the foot and dorsiflexion of the foot, respectively. The superficial and deep peroneal nerves provide both motor and sensory innervation.
The most common presentation with common peroneal nerve injury or palsy is acute foot drop, although symptoms may be progressive and can include sensory loss or pain. Weakness in foot eversion may occur if the superficial peroneal nerve component is involved.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 2
Correct
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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 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 3
Incorrect
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Diagnosis of HIV is predominantly made through which of the following:
Your Answer: Viral PCR
Correct Answer: Antibody detection
Explanation:Diagnosis of HIV is predominantly made through detection of HIV antibody and p24 antigen. Viral load (viral PCR) and CD4 count are used to monitor progression of disease.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 4
Correct
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On his stool culture, a patient with a diarrhoeal illness grows Escherichia coli.
What SINGLE statement about Escherichia coli is true?
Your Answer: Most serotypes are harmless
Explanation:Escherichia coli is a Gram-negative, non-spore forming, facultative anaerobic, rod-shaped bacterium.
Although some can cause serious food poisoning, most serotypes are harmless.
Escherichia coli is transmitted via the faeco-oral route.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 5
Correct
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Naloxone is a reversal agent for which of the following groups of drugs:
Your Answer: Opioids
Explanation:Naloxone is a specific antagonist of mu(μ)-opioid receptors, the specific antidote for opioid overdose and will reverse respiratory depression and coma if given at sufficient dosage. The initial dose is usually 0.8 mg (2 mL) intravenously (the dose range suggested by BNF is 0.4-2 mg). It can also be given by intramuscular injection if the intravenous route is not feasible.
As naloxone has a shorter duration of action than most opioids, close monitoring and repeated injections are necessary according to the respiratory rate and depth of coma. The dose is generally repeated every 2-3 minutes to a maximum of 10 mg. When repeated doses are needed, naloxone may be given by a continuous infusion adjusted according to the vital signs. Initially, the infusion rate can be set at 60% of the initial resuscitative IV dose per hour.
In opioid addicts, naloxone administration may precipitate a withdrawal syndrome with abdominal cramps, nausea and diarrhoea, but these usually settle within 2 hours. -
This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 6
Correct
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You assess a patient that has suffered a nerve injury that has paralysed her left latissimus dorsi muscle.
Latissimus dorsi receives its innervation from which of the following nerves? Select ONE answer only.Your Answer: Thoracodorsal nerve
Explanation:Latissimus dorsi originates from the lower part of the back, where it covers a wide area. It lies underneath the inferior fibres of trapezius superiorly, and trapezius is the most superficial back muscle.
Superficial muscles of the back showing latissimus dorsi (from Gray’s Anatomy)
Latissimus dorsi has a broad origin, arising from the spinous processes of T6-T12, the thoracolumbar fascia, the iliac crest and the inferior 3 or 4 ribs. The fibres converge into a tendon that inserts into the intertubercular groove of the humerus.
Latissimus dorsi is innervated by the thoracodorsal nerve.
Latissimus dorsi acts to extend, adduct and medially rotate the humerus. It, therefore, raises the body towards the arm during climbing. -
This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 7
Incorrect
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Regarding bronchiolitis, which of the following statements is CORRECT:
Your Answer: It occurs most commonly from infection with parainfluenza virus.
Correct Answer: Chest x-ray may show hyperinflation and increased peribronchial markings.
Explanation:Acute bronchiolitis is caused most commonly by respiratory syncytial virus, occurring mostly in children aged 6 months to 2 years. Children with bronchiolitis are febrile and tachypnoeic with a dry cough and difficulty feeding. Examination may reveal chest hyperinflation, respiratory distress, wheezing and fine end-inspiratory crepitations. Chest x-ray may show hyperinflation and increased peribronchial markings (although CXR should only performed if there is diagnostic uncertainty or an atypical course). Treatment is usually supportive, aerosolized ribavirin is reserved for severely ill or immunocompromised patients.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 8
Incorrect
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A 20-year-old patient had sustained a supracondylar fracture due to falling from a skateboard. The frequency of acute nerve injuries accompanying supracondylar humeral fractures ranges from 10 to 20%. The most common complication is injury to which nerve?
Your Answer: Ulnar nerve
Correct Answer: Median nerve
Explanation:According to various studies, the frequency of acute nerve damage associated with supracondylar humeral fractures in children ranges from 10% to 20%.
Median nerve injury and anterior interosseous nerve injury are the most common consequences.
Damage to this nerve indicated weakening or abnormal extension of the index finger’s distal interphalangeal joint and the thumb’s interphalangeal joint. The absence of sensibility is a distinguishing attribute.
A surgical neck humerus fracture may cause injury to the axillary nerve. A midshaft humerus fracture might cause injury to the radial nerve. A medial epicondylar fracture might cause injury to the ulnar nerve.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 9
Correct
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The term cardiac output refers to the amount of blood pumped by the heart in one minute. The rate in women is around 5 L/min, whereas in men is somewhat higher, around 5.5 L/min.
Which of the equations below best describes cardiac output?
Your Answer: Stroke volume x heart rate
Explanation:Cardiac output (CO) is calculated by multiplying stroke volume (SV) by heart rate (HR):
CO = HR x SVAs a result, both stroke volume and heart rate are exactly proportional to cardiac output. There will be an increase in cardiac output if the stroke volume or heart rate increases, and a reduction in cardiac output if the stroke volume or heart rate lowers.
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This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
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Question 10
Correct
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Flumazenil is a reversal agent for which of the following groups of drugs:
Your Answer: Benzodiazepines
Explanation:Flumazenil is a benzodiazepine antagonist used for the reversal of the sedative effects of benzodiazepines after anaesthesia, sedation and similar procedures.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 11
Correct
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Which of the following best describes the order in which blood passes through the nephron?
Your Answer: Afferent arteriole→Glomerular capillary→Efferent arteriole→Peritubular capillary→Vasa recta
Explanation:The nephron’s blood flow is as follows:
Afferent arteriole – Glomerular capillary – Efferent arteriole – Peritubular capillary – Vasa recta – Afferent arteriole – Glomerular capillary – Efferent arteriole – Peritubular capillary – Vasa rectaThe kidney is the only vascular network in the body with two capillary beds. With arterioles supplying and draining the glomerular capillaries, higher hydrostatic pressures at the glomerulus are maintained, allowing for better filtration. A second capillary network at the tubules enables for secretion and absorption in the tubules, as well as concentrating urine.
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 12
Correct
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A 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: 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 13
Incorrect
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A 29-year-old man is diagnosed with a severe case of asthma.
In the treatment of acute asthma in adults, which of the following is NOT recommended?Your Answer: IV salbutamol
Correct Answer: Nebulised magnesium
Explanation:There is no evidence to support the use of nebulized magnesium sulphate in the treatment of adults at this time.
In adults with acute asthma, the following medication dosages are recommended:
By using an oxygen-driven nebuliser, you can get 5 milligrams of salbutamol.
500 mcg ipratropium bromide in an oxygen-driven nebuliser
Oral prednisolone 40-50 mg
100 mg hydrocortisone intravenous
1.2-2 g magnesium sulphate IV over 20 minutes
When inhaled treatment is ineffective, intravenous salbutamol (250 mcg IV slowly) may be explored (e.g. a patient receiving bag-mask ventilation).Following senior counsel, current ALS recommendations propose that IV aminophylline be explored in severe or life-threatening asthma. If utilized, a loading dose of 5 mg/kg should be administered over 20 minutes, then a 500-700 mcg/kg/hour infusion should be given. To avoid toxicity, serum theophylline levels should be kept below 20 mcg/ml.
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This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 14
Correct
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Which of the following nerves is most likely associated with an anterior shoulder dislocation?
Your Answer: Axillary nerve
Explanation:In an anterior dislocation, the arm is an abducted and externally rotated position. In the externally rotated position, the posterosuperior aspect of the humeral head abuts and drives through the anteroinferior aspect of the glenoid rim. This can damage the humeral head, glenoid labrum, or both. An associated humeral head compression fracture is described as a Hill Sach’s lesion. If large enough, it can lead to locked dislocations that may require open reduction. The glenoid labrum is a fibrocartilaginous structure that rings the circumference of the glenoid fossa. Bankart lesions are injuries to the anteroinferior glenoid labrum complex and the most common capsulolabral injury. A bony Bankart lesion refers to an associated fracture of the glenoid rim. These capsulolabral lesions are risk factors for recurrent dislocation.
Axillary nerve injury is identified in about 42% of acute anterior shoulder dislocations. Nerve transection is rare, and traction injuries are more common. Arterial injury has also been described. The subclavian artery becomes the axillary artery after passing the first rib. The distal portion of the axillary artery is anatomically fixed and, therefore, susceptible to injury in anterior dislocations. Ischemic injury, including pseudoaneurysm and arterial laceration, is rare but carries marked morbidity if not quickly identified.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 15
Correct
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Which of the following is NOT one of the cardinal features of acute inflammation:
Your Answer: Discharge
Explanation:Classic signs:
Rubor (redness)
Calor (heat)
Dolour (pain)
Tumour (swelling)
Functio laesa (loss of function)
These classic signs are produced by a rapid vascular response and cellular events. The main function of these events is to bring elements of the immune system to the site of injury and prevent further tissue damage. -
This question is part of the following fields:
- Inflammatory Responses
- Pathology
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Question 16
Incorrect
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Which of the following classes of drugs may predispose to lithium toxicity:
Your Answer: Theophylline
Correct Answer: Thiazide diuretics
Explanation:Excretion of lithium may be reduced by thiazide diuretics, NSAIDs, and ACE inhibitors thus predisposing to lithium toxicity. Loop diuretics also cause lithium retention but are less likely to result in lithium toxicity.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 17
Incorrect
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An injury to which nerve affects innervation to the adductor portion of the adductor magnus?
Your Answer: Anterior branch of the obturator nerve
Correct Answer: Posterior branch of the obturator nerve
Explanation:The nerves that supply the adductor magnus muscle have an embryologic origin from the anterior divisions of the lumbosacral plexus and include the obturator nerve, posterior division (L2-4), and the tibial portion of the sciatic nerve (L4). It is innervated by the posterior division of the obturator nerve.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 18
Correct
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Question 19
Incorrect
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The ECG of a patient presenting with a history of intermittent palpitations has a prolonged QT interval.
Which of these can cause prolongation of the QT interval on the ECG?Your Answer: Hyperkalaemia
Correct Answer: Hypomagnesaemia
Explanation:The causes of a prolonged QT interval include:
Hypomagnesaemia
Hypothermia
Hypokalaemia
Hypocalcaemia
Hypothyroidism
Jervell-Lange-Nielsen syndrome (autosomal dominant)
Romano Ward syndrome (autosomal recessive)
Ischaemic heart disease
Mitral valve prolapse
Rheumatic carditis
Erythromycin
Amiodarone
Quinidine
Tricyclic antidepressants
Terfenadine
Methadone
Procainamide
Sotalol -
This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
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Question 20
Incorrect
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Regarding the partial pressure of gases, which of the following statements is INCORRECT:
Your Answer: The total pressure exerted by the atmosphere at sea level is 760 mmHg (101 kPa).
Correct Answer: At high altitude, the oxygen fraction is reduced.
Explanation:At altitude, the oxygen fraction is unaltered but the barometric pressure and thus partial pressure of oxygen is reduced.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 21
Correct
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The risk of renal impairment in a patient on ACE inhibitor therapy is increased by concomitant treatment with which of the following drug classes:
Your Answer: NSAIDs
Explanation:Concomitant treatment with NSAIDs increases the risk of renal damage, and with potassium-sparing diuretics (or potassium-containing salt substitutes) increases the risk of hyperkalaemia. Hyperkalaemia and other side effects of ACE inhibitors are more common in the elderly and in those with impaired renal function and the dose may need to be reduced.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 22
Correct
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Which of the following muscles acts as an extensor of the shoulder joint?
Your Answer: Teres major
Explanation:The glenohumeral joint possesses the capability of allowing an extreme range of motion in multiple planes.
Flexion – Defined as bringing the upper limb anterior in the sagittal plane. The usual range of motion is 180 degrees. The main flexors of the shoulder are the anterior deltoid, coracobrachialis, and pectoralis major. Biceps brachii also weakly assists in this action.
Extension—Defined as bringing the upper limb posterior in a sagittal plane. The normal range of motion is 45 to 60 degrees. The main extensors of the shoulder are the posterior deltoid, latissimus dorsi, and teres major.
Internal rotation—Defined as rotation toward the midline along a vertical axis. The normal range of motion is 70 to 90 degrees. The internal rotation muscles are the subscapularis, pectoralis major, latissimus dorsi, teres major, and the anterior aspect of the deltoid.
External rotation – Defined as rotation away from the midline along a vertical axis. The normal range of motion is 90 degrees. Primarily infraspinatus and teres minor are responsible for the motion.
Adduction – Defined as bringing the upper limb towards the midline in the coronal plane. Pectoralis major, latissimus dorsi, and teres major are the muscles primarily responsible for shoulder adduction.
Abduction – Defined as bringing the upper limb away from the midline in the coronal plane. The normal range of motion is 150 degrees. Due to the ability to differentiate several pathologies by the range of motion of the glenohumeral joint in this plane of motion, it is essential to understand how different muscles contribute to this action.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 23
Correct
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All of the following statements are considered true regarding likelihood ratios, except:
Your Answer: A likelihood ratio less than 1 indicates that the result is associated with the presence of the disease
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 24
Incorrect
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A 56-year-old man presents with pneumonia 8 days after being admitted for an open fracture of his tibia and fibula. Upon history taking and observation, it was established that he has no known drug allergies, has coarse left basal crackles and evidence of consolidation in the left lower lobe based on his chest X-ray.
Which of the following antibacterial agents would be the most appropriate to prescribe according to the latest NICE guidelines?Your Answer: Co-amoxiclav
Correct Answer: Ciprofloxacin
Explanation:The current NICE guidelines for hospital-acquired pneumonia are as follow:
– First-choice oral antibiotic if non‑severe symptoms or signs, and not at higher risk of resistance (guided by microbiological results when available): co-amoxiclav– Alternative oral antibiotics if non‑severe symptoms or signs, and not at higher risk of resistance, for penicillin allergy or if co‑amoxiclav unsuitable (based on specialist microbiological advice and local resistance data): doxycycline, cefalexin, co-trimoxazole, levofloxacin
– First-choice intravenous antibiotics if severe symptoms or signs (for example, symptoms or signs of sepsis) or at higher risk of resistance (based on specialist microbiological advice and local resistance data): piperacillin with tazobactam, ceftazidime, ceftriaxone, cefuroxime, meropenem, ceftazidime with avibactam, levofloxacin
– Antibiotics to be added if suspected or confirmed methicillin-resistant Staphylococcus aureus infection (dual therapy with a first-choice intravenous antibiotic): vancomycin, teicoplanin, linezolid
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 25
Correct
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Regarding aciclovir, which of the following statements is INCORRECT:
Your Answer: Aciclovir eradicates herpes simplex virus from the body.
Explanation:Aciclovir is active against herpesviruses but does not eradicate latent virus.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 26
Correct
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You're evaluating a male patient who's having a lung function test done. In calculating the patient’s functional residual capacity, what parameters should you add to derive the functional residual capacity volume?
Your Answer: Expiratory reserve volume + residual volume
Explanation:The volume of air that remains in the lungs after a single breath is known as functional residual capacity (FRC). It is calculated by combining the expiratory reserve volume and residual volume.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 27
Incorrect
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A 5-year-old girl is brought into the Paediatric ER for acute seizures. She has been convulsing for the past 18 minutes now and was already two doses of lorazepam in the ambulance. Now, you prepare a phenytoin infusion to abolish the seizures.
According to the APLS algorithm, what dose of phenytoin is advised for a convulsing child at this stage?Your Answer: 100 mg/kg over 20 minutes
Correct Answer: 20 mg/kg over 20 minutes
Explanation:Advanced paediatric life support (APLS) recommends phenytoin as the first choice for second-line anticonvulsant in a patient that continues to seize ten minutes after the second dose of the first-line anticonvulsant (benzodiazepine). (step 3 of the APLS algorithm)
The recommended dose of phenytoin infusion is up at 20 mg/kg over 20 minutes. If the patient has already taken phenytoin as maintenance therapy or is allergic to phenytoin, then a phenobarbitone infusion should be set up at 20 mg/kg over 30-60 minutes.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 28
Correct
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Which of the following statements is correct regarding anti-D immunoglobulin?
Your Answer: It is administered as part of routine antenatal care for rhesus-negative mothers.
Explanation:In all non-sensitised pregnant women who are RhD-negative, it is recommended that routine antenatal anti-D prophylaxis is offered. Even if there is previous anti-D prophylaxis, use of routine antenatal anti-D prophylaxis should be given for a sensitising event early in the same pregnancy. Postpartum anti-D prophylaxis should also be given even if there has been previous routine antenatal anti-D prophylaxis or antenatal anti-D prophylaxis for a sensitising event in the same pregnancy.
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This question is part of the following fields:
- Immunoglobulins And Vaccines
- Pharmacology
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Question 29
Correct
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A 30-year old male is taken to the emergency room after suffering a blunt trauma to the abdomen. He is complaining of severe abdominal pain, however all his other vital signs remain stable. A FAST scan is performed to assess for hemoperitoneum.
If hemoperitoneum is present, it is most likely to be observed in which of the following areas?Your Answer: Liver
Explanation:The Focused Assessment with Sonography in Trauma (FAST) is an ultrasound protocol developed to assess for hemoperitoneum and hemopericardium. Numerous studies have demonstrated sensitivities between 85% to 96% and specificities exceeding 98%.
The FAST exam evaluates four regions for pathologic fluid: (1) the right upper quadrant, (2) the subxiphoid (or subcostal) view, (3) the left upper quadrant, and (4) the suprapubic region.
The right upper quadrant (RUQ) visualizes the hepatorenal recess, also known as Morrison’s pouch, the right paracolic gutter, the hepato-diaphragmatic area, and the caudal edge of the left liver lobe. The probe is positioned in the sagittal orientation along the patient’s flank at the level of the 8 to 11 rib spaces. The hand is placed against the bed to ensure visualization of the retroperitoneal kidney. The RUQ view is the most likely to detect free fluid with an overall sensitivity of 66%. Recent retrospective evidence suggests the area along the caudal edge of the left lobe of the liver has the highest sensitivity, exceeding 93%.
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This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 30
Correct
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Regarding alteplase, which of the following statements is INCORRECT:
Your Answer: Alteplase is commonly associated with hypotensive effects.
Explanation:Alteplase is a recombinant tissue-type plasminogen activator (tPA), a naturally occurring fibrin-specific enzyme that has selectivity for activation of fibrin-bound plasminogen. It has a short half-life of 3 – 4 minutes and must be given by continuous intravenous infusion but is not associated with antigenic or hypotensive effects, and can be used in patients when recent streptococcal infections or recent use of streptokinase contraindicates the use of streptokinase.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 31
Correct
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Which of the following microbes binds strongly to CD4 antigen:
Your 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. -
This question is part of the following fields:
- Microbiology
- Principles
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Question 32
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 / ΔP
Where:
ΔV is the change in volume
ΔP 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 33
Correct
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A 35 year old patient presents to ED having sustained an injury to his right hand whilst playing cricket. He is unable to fully straighten his right middle finger as the distal phalanx remains flexed. Which of the following structures within the digit was most likely injured:
Your Answer: Insertion of terminal extensor digitorum tendon
Explanation:Damage to the insertion of the terminal extensor digitorum tendon would result in loss of extension at the distal interphalangeal joint causing a fixed flexion deformity, called the Mallet deformity.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 34
Incorrect
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Compliance is decreased by all but which one of the following:
Your Answer: Atelectasis
Correct Answer: Aging
Explanation:Factors increasing compliance:
Old age
EmphysemaFactors decreasing compliance:
Pulmonary fibrosis
Pulmonary oedema
Atelectasis
Extremes of lung volumes (at higher lung volumes the compliance of the lung becomes less as the lung becomes stiffer) -
This question is part of the following fields:
- Physiology
- Respiratory
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Question 35
Incorrect
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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: ELISA antibody 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 36
Correct
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What is the approximate lifespan of the mature erythrocyte:
Your 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 37
Correct
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An ambulance transports a 72-year-old woman to the Emergency Department. She is confused, has been vomiting and having stomach pains. Digoxin is one of her medications.
Which of the following claims about digoxin is correct?Your Answer: Therapeutic plasma levels are between 1.0-1.5 nmol/l
Explanation:Digoxin is a cardiac glycoside that is used to treat atrial fibrillation and flutter, as well as congestive heart failure. In cardiac myocytes, it works by inhibiting the membrane Na/K ATPase. Through Na/Ca exchange, this raises intracellular sodium concentration and indirectly increases intracellular calcium availability. Increased intracellular calcium levels have both a positive inotropic and negative chronotropic effect.
Digoxin therapeutic plasma levels are typically between 1.0 and 1.5 nmol/l, though higher concentrations may be required, and the value varies between laboratories. At concentrations greater than 2 nmol/l, the risk of toxicity increases dramatically.
In patients with normal renal function, digoxin has a long plasma half-life of 36 to 48 hours. This can take up to 5 days in patients with impaired renal function.
Hypokalaemia, rather than hyperkalaemia, has been shown to increase the risk of digoxin toxicity.
In the treatment of persistent and permanent atrial fibrillation, digoxin is no longer widely used. Beta-blockers, also known as rate-limiting calcium channel blockers, are now the first-line treatment for this condition.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 38
Incorrect
-
Which of the following is true regarding respiration?
Your Answer: The ‘pump handle’ action of the ribs increases the transverse diameter of the chest
Correct Answer: The diaphragm is responsible for abdominal breathing
Explanation:The following are the mechanisms of breathing during inspiration and expiration, whether normal or forced.
Normal inspiration is an active process, with the diaphragm as the main muscle. The diaphragm descends, ribs move upward and outward, and the lungs become wider and taller.
In forced inspiration, which commonly occurs during exercise, the external intercostals and accessory muscles, such as the sternocleidomastoid, anterior serrati, scalenes, alae nasi, genioglossus and arytenoid are involved. The ribs move upward and outward, and the abdominal contents move downward.
Normal expiration is a passive process, while in forced expiration, the internal intercostals and abdominal muscles, such as the rectus abdominis, internal and external obliques and transversus abdominis are involved. The ribs move downward and inward, and the abdominal contents move upward.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 39
Correct
-
Which of the following is diagnostic for acute hepatitis B infection:
Your Answer: anti-HBc IgM
Explanation:Anti-HBc IgM antibodies are diagnostic for acute hepatitis B infection. Anti-HBc IgG antibodies indicate previous exposure, either chronic state or cleared infection. HBsAg is also positive in acute infection but is not diagnostic as this remains positive in chronic infection.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 40
Correct
-
Regarding endothelin-1, which of the following statements is INCORRECT:
Your Answer: Endothelin-1 release is inhibited by noradrenaline.
Explanation:Endothelin-1 (ET-1) is an extremely potent vasoconstrictor peptide which is released from the endothelium in the presence of many other vasoconstrictors, including angiotensin II, antidiuretic hormone (ADH) and noradrenaline, and may be increased in disease and hypoxia.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 41
Incorrect
-
Regarding cross-sectional studies, which of the following statements is CORRECT:
Your Answer: They are useful for considering trends over time.
Correct Answer: They are particularly suitable for estimating point prevalence.
Explanation:Cross-sectional studies aim to provide data about population health, normal ranges of biological parameters, and disease prevalence or severity by observing the entire population, or a representative subset, at a single point in time. Cross-sectional studies are relatively simple and quick to perform and can be used to study multiple outcomes, but are subject to confounding and recall bias and are not suitable for studying rare diseases. Cross-sectional studies cannot be used to assess causation or to consider trends over time.
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This question is part of the following fields:
- Evidence Based Medicine
- Study Methodology
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Question 42
Correct
-
A 60-year-old man with trauma to his cervical spine suffers from damage to the ansa cervicalis, resulting to paresis of his infrahyoid muscles.
All of the following are considered infrahyoid muscles, except:Your Answer: Mylohyoid
Explanation:Infrahyoid muscles are also known as “strap muscles” which connect the hyoid, sternum, clavicle and scapula. They are located below the hyoid bone on the anterolateral surface of the thyroid gland and are involved in movements of the hyoid bone and thyroid cartilage during vocalization, swallowing and mastication. They are composed of four paired muscles, organized into two layers.
Superficial layer consists of the sternohyoid and omohyoid
Deep layer consists of the sternothyroid and thyrohyoid. -
This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 43
Correct
-
At which opioid receptors do opioid analgesics act primarily?
Your Answer: Mu
Explanation:Opioid receptors are widely distributed throughout the central nervous system. Opioid analgesics mimic endogenous opioid peptides by causing prolonged activation of these receptors, mainly the mu(μ)-receptors which are the most highly concentrated in brain areas involved in nociception.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 44
Correct
-
The blood test reports of a 56-year-old female are sent for your review. She seems acutely sick and has had multiple infections over the past few months. Her complete blood count report shows neutropenia.
Which one of the following options is true with regards to neutropenia?Your Answer: It can be caused by both radiotherapy and chemotherapy
Explanation:A total neutrophil count of less than 2 x 109/L is defined as neutropenia. It can be caused by the following:
1. viral infections
2. SLE
3. RA
4. hypersplenism
5. chemo- and radiotherapy
6. vitamin B12 and folate deficiency
7. drug reactions -
This question is part of the following fields:
- Haematology
- Pathology
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Question 45
Incorrect
-
A 45-year-old man, a known case of epilepsy, visits his neurologist with complaints of red, swollen gums.
Which of the following medications is most likely responsible for his symptoms?Your Answer: Lamotrigine
Correct Answer: Phenytoin
Explanation:Phenytoin is a commonly used antiepileptic drug. A well-recognized side-effect of phenytoin is gingival enlargement and occurs in about 50% of patients receiving phenytoin. It is believed that reduced folate levels may cause this, and evidence suggests that folic acid supplementation may help prevent this in patients starting phenytoin.
As evidence suggests, drug-induced gingival enlargement may also improve by substituting with other anticonvulsant drugs and reinforcing a good oral hygiene regimen. Surgical excision of hyperplastic gingiva is often necessary to correct the aesthetic and functional impairment associated with this condition to manage it successfully.
Phenytoin is also the only anticonvulsant therapy associated with the development of Dupuytren’s contracture.
Other side effects are:
1. Ataxia
2. Drug-induced lupus
3. Hirsutism
4. Pruritic rash
5. Megaloblastic anaemia
6. Nystagmus -
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 46
Correct
-
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 47
Incorrect
-
You are reviewing a patient following a fall from a horse. You suspect they may have an Erb's palsy as a result of a brachial plexus injury. Regarding Erb's palsy, which one of the following statements is CORRECT:
Your Answer: Erb's palsy characteristically results in Waiter's tip deformity where the arm is held in lateral rotation.
Correct Answer: Erb's palsy may result in loss of sensation of the regimental badge area.
Explanation:Erb’s palsy is caused by damage to the C5 and C6 nerve roots and thus primarily involves the musculocutaneous, suprascapular and axillary nerves. It commonly result from an excessive increase in the angle between the neck and the shoulder e.g. a person thrown from a motorbike or horseback or during a difficult birth. There is loss or weakness of abduction, lateral rotation and flexion of the arm and flexion and supination of the forearm and loss of sensation on the lateral arm. A characteristic ‘Waiter’s tip’ deformity may be present where the limb hangs limply by the side, medially rotated by the unopposed action of pectoralis major with the forearm pronated due to paralysis of the biceps brachii.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 48
Incorrect
-
An analytical study is conducted to compare the risk of stroke between Ticagrelor therapy and Warfarin therapy among patients with atrial fibrillation. The following is obtained from the study:
No. of patients who took Ticagrelor: 300
No. of patients who took Ticagrelor and suffered a stroke: 30
No. of patients who took Warfarin: 500
No. of patients who took Warfarin and suffered a stroke: 20
Compute for the absolute risk reduction of a stroke, with Warfarin as the standard of treatment.Your Answer: 0.06
Correct Answer: -0.06
Explanation:Absolute risk reduction (ARR) is computed as the difference between the absolute risk in the control group (ARC) and the absolute risk in the treatment group (ART).
Since Warfarin is the standard of treatment, Warfarin is considered as the control group.
ARR = ARC-ART
ARR = (20/500) – (30/300)
ARR = -0.06This means that there is increased risk of stroke in the treatment group, which is the Ticagrelor group.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 49
Correct
-
A patient presents with a gastrointestinal infection. Which of the following microbes attaches to gut mucosa via a specialised sucking disc:
Your Answer: Giardia lamblia
Explanation:Giardia lambliainfection occurs through the ingestion of dormant microbial cysts in contaminated water, food or via faceo-oral transmission via poor hygiene.
Following ingestion of the cysts, the trophozoite emerges to an active state of feeding and motility. After the feeding stage they undergo asexual replication through longitudinal binary fission.
They attach to the intestinal wall via a specialised sucking disc. The mechanism for diarrhoea in giardiasis remains unknown but could possibly be due to direct cytotoxicity.
Giardial trophozoites and cysts pass through the digestive system in the faeces and are excreted. While the trophozoites may be found in the faeces, only the cysts are adapted for long-term survival outside the host. -
This question is part of the following fields:
- Microbiology
- Principles
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Question 50
Correct
-
All of the following statements are correct regarding the management of acute asthma in adults except:
Your Answer: Intravenous aminophylline has been shown to result in significant additional bronchodilation compared to standard care.
Explanation:There usually isn’t any additional bronchodilation with intravenous (IV) aminophylline compared to standard care with inhaled bronchodilators and steroids. IV aminophylline may cause side effects such as arrhythmias and vomiting. However, some additional benefit may be gained in patients with near-fatal asthma or life-threatening asthma with a poor response to initial therapy (5 mg/kg loading dose over 20 minutes unless on maintenance oral therapy, then continuous infusion of 0.5 – 0.7 mg/kg/hr).
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 51
Correct
-
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: 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) Malignancy
3) Pericarditis
4) 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 52
Correct
-
During her pregnancy, a 28-year-old lady was given an antibiotic. The neonate is born with bilateral deafness as a result of this.
From the following antibiotics, which one is most likely to cause this side effect?Your Answer: Gentamicin
Explanation:Aminoglycosides cross the placenta and are linked to poisoning of the 8th cranial nerve in the foetus, as well as permanent bilateral deafness.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 53
Correct
-
Digoxin is predominantly used for which of the following:
Your Answer: Rate control in persistent and permanent atrial fibrillation
Explanation:Digoxin is most useful for controlling the ventricular response in persistent and permanent atrial fibrillation and atrial flutter. Digoxin is usually only effective for controlling the ventricular rate at rest, and should therefore only be used as monotherapy in predominantly sedentary patients with non-paroxysmal atrial fibrillation. It is now rarely used for rapid control of heart rate, as even with intravenous administration, response may take many hours. Digoxin is reserved for patients with worsening or severe heart failure due to left ventricular systolic dysfunction refractory to combination therapy with first-line agents. Digoxin is contraindicated in supraventricular arrhythmias associated with accessory conduction pathways e.g. Wolff-Parkinson-White syndrome.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 54
Correct
-
Contraction of the diaphragm results in which of the following effects:
Your Answer: Increased vertical dimension of the thorax
Explanation:Contraction of the diaphragm (as in inspiration) results in flattening (depression) of the diaphragm with an increase in vertical dimension of the thorax. This results in decreased intrathoracic pressure and increased intra-abdominal pressure.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 55
Correct
-
Which of the following corticosteroids has the most potent mineralocorticoid effect:
Your 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 56
Correct
-
A 24-year-old athlete drinks a 500 ml hypertonic sports drink before an endurance event he participates in.
Which of the following effects will this cause?Your Answer: The interstitial fluid becomes more concentrated
Explanation:Osmosis is the passive movement of water across a semipermeable membrane from a region of low solute concentration to a region of higher solute concentration.
When hypertonic fluid is ingested:
The plasma becomes CONCENTRATED.The cells lose water and shrink
The intracellular fluid becomes more concentrated.
Water and ions move freely from the plasma into the interstitial fluid and the interstitial fluid becomes more concentrated.
The increased osmotic potential draws water out of the cells. -
This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 57
Correct
-
Which of the following is NOT a common effect of etomidate:
Your Answer: Significant hypotension
Explanation:Etomidate causes less hypotension than thiopental sodium and propofol during induction. However, it is associated with a high incidence of extraneous muscle movements, which can be minimised by an opioid analgesic or a short-acting benzodiazepine given prior to induction. Pain on injection is common and there is a high rate of thrombophlebitis in the postoperative period. Postoperative nausea and vomiting commonly occur. Etomidate suppresses adrenocortical function, particularly during continuous administration, and it should not be used for maintenance of anaesthesia. It should be used with caution in patients with underlying adrenal insufficiency, for example, those with sepsis.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 58
Incorrect
-
Which of the following statements is correct with regards to heparin-induced thrombocytopaenia (HIT)?
Your Answer: Further anticoagulation should be avoided until HIT has resolved.
Correct Answer: HIT typically develops 5-10 days after starting heparin.
Explanation:Heparin-induced thrombocytopenia (HIT) is a prothrombotic disorder caused by antibodies that recognize complexes of platelet factor 4 (PF4) and heparin. HIT is frequently considered in the differential diagnosis of thrombocytopenia occurring in patients on heparin therapy. HIT is a challenging diagnosis because of routine heparin use in hospitalized patients, the common occurrence of thrombocytopenia. The process of heparin dependent IgG antibodies binding to heparin/platelet factor 4 complexes activates platelets and produces a hypercoagulable state. This syndrome typically develops 5-10 days (range 4-15 days) after heparin is commenced. It can occur with unfractionated heparin, low molecular weight heparin, or, rarely, fondaparinux. The diagnosis of HIT requires the combination of a compatible clinical picture and laboratory confirmation of the presence of heparin dependent platelet activating HIT antibodies. Discontinuation of heparin alone or initiation of a vitamin K antagonist alone like warfarin, is not sufficient to stop the development of thrombosis in patients with acute HIT. If there is moderate clinical suspicion for HIT, all sources of heparin must be discontinued and there must be consideration of anticoagulant treatment with a non-heparin drug.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 59
Correct
-
In the Emergency Department, a 35-year-old woman actively seizing is brought in. She is quickly shifted into the resuscitation room and is administered a dose of benzodiazepine. The seizure is quickly terminated.
Once the patient is stable, she tells you she is a known case of epilepsy and takes phenytoin to control it.
Which of the following is the primary mechanism of action of phenytoin?Your Answer: Sodium channel blocker
Explanation:Phenytoin is in the anticonvulsants class of drugs and is used in the management and treatment of the following:
1. epilepsy
2. generalized tonic-clonic seizures
3. complex partial seizures
4. status epilepticus.It works by inactivating the voltage-gated sodium channels responsible for increasing the action potential. It is non-specific and targets almost all voltage-gated sodium channel subtypes. More specifically, phenytoin prevents seizures by inhibiting the positive feedback loop that results in neuronal propagation of high-frequency action potentials.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 60
Incorrect
-
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: Clarithromycin
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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Question 61
Incorrect
-
What is the interquartile range of the following data set: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70
Your Answer: 20
Correct Answer: 30
Explanation:5, 10, 15 /20, 25, 30 /35, 40, 45 /50, 60, 70
Sample size (n) = 12
Median = [(n+1)/2]th value
= (12+1)/2 = 6.5
= halfway between 6th and 7th value
= (30 +35)/2 = 32.5
The lower (first) quartile = halfway between 15 and 20
= 17.5
The upper (third) quartile = halfway between 45 and 50
= 47.5
The interquartile range is the difference between the upper quartile and lower quartile
= 47.5 – 17.5 = 30 -
This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 62
Incorrect
-
The average BP reading on ambulatory blood pressure monitoring for a 59-year-old Caucasian man is 152/96 mmHg (ABPM).
The first-line drug treatment for this patient would be which of the following? Please only choose ONE answer.Your Answer: Ramipril
Correct Answer: Amlodipine
Explanation:An ambulatory blood pressure reading of >150/95 is classified as stage 2 hypertension, according to the NICE care pathway for hypertension, and the patient should be treated with an antihypertensive drug.
A calcium-channel blocker, such as amlodipine, would be the most appropriate medication for a 59-year-old Caucasian man.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 63
Incorrect
-
Regarding the refractory period, which of the following statements is INCORRECT:
Your Answer: Action potentials cannot occur in the absolute refractory period.
Correct Answer: Action potentials can occur in the relative refractory period but the amplitude of the action potential is smaller.
Explanation:Following the action potential, Na+channels remain inactive for a time in a period known as the absolute refractory period where they cannot be opened by any amount of depolarisation. Following this there is a relative refractory period where the temporary hyperpolarisation (due to delayed closure of rectifier K+channels) makes the cell more difficult to depolarise and an action potential can be generated only in response to a larger than normal stimulus. The refractory period limits the frequency at which action potentials can be generated, and ensures that, once initiated, an action potential can travel only in one direction. An action potential is an all or nothing response so the amplitude of the action potential cannot be smaller.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 64
Correct
-
You are treating a patient with a Clostridium difficile infection. His condition was found to be antibiotic-associated. Which of the following pieces of advice on preventing the spread of this disease should you give this patient?
Your Answer: Washing hands with soap and water
Explanation:Clostridium difficile (C. diff) can cause colitis, or inflammation of the colon.
To prevent its spread, one should practice good hand hygiene, regularly clean areas of the home that may become contaminated with C. difficile, practice good hand hygiene, and clean surfaces, spills, and accidents.
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This question is part of the following fields:
- Microbiology
- Principles
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Question 65
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: 99%
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 66
Incorrect
-
Which of the following is a physiological function that is mediated by a hormone released by the posterior pituitary:
Your Answer: Milk production
Correct Answer: Water retention
Explanation:Antidiuretic hormone (ADH), released by the posterior pituitary, acts on the kidneys to increase water permeability in the distal nephron allowing greater water reabsorption and concentration of urine. Prolactin, from the anterior pituitary, is responsible for milk production. The thyroid hormones, from the thyroid gland, are responsible for an increase in basal metabolic rate (stimulated by TSH from the anterior pituitary). FSH/LH, from the anterior pituitary, are responsible for maturation of egg and sperm. Calcitonin, from the thyroid gland, is responsible for decreasing calcium levels.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 67
Incorrect
-
An 11-year-old presented to a GP with a history of headache, neck stiffness and photophobia. On examination, HR is 122, BP is 87/42, RR is 28, SaO 2 is 95%, temperature is 39.4 o C. There is a recent petechial rash on legs and arms. The GP administered a dose of antibiotics in the prehospital setting before transferring to the Emergency Department. Which of these would the GP have administered?
Your Answer: IM benzylpenicillin 600 mg
Correct Answer: IM benzylpenicillin 1.2 g
Explanation:General Practitioners are advised to give a single injection of benzylpenicillin by intravenous or intramuscular injection before transferring the patient urgently to the ED when bacterial meningitis is suspected.
The recommended doses are:
Infants under 1 year: 300 mg
Children ages 1 to 9 years: 600 mg
Children aged 10 years and over: 1.2g
Adults: 1.2g -
This question is part of the following fields:
- Infections
- Pharmacology
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Question 68
Correct
-
Which of the following clinical features is a feature of a chronic extravascular haemolytic anaemia:
Your Answer: Gallstones
Explanation:Clinical features of haemolytic anaemia include:
Anaemia
Jaundice (caused by unconjugated bilirubin in plasma, bilirubin is absent from urine)
Pigment gallstones
Splenomegaly
Ankle ulcers
Expansion of marrow with, in children, bone expansion e.g. frontal bossing in beta-thalassaemia major
Aplastic crisis caused by parvovirus -
This question is part of the following fields:
- Haematology
- Pathology
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Question 69
Incorrect
-
A patient is referred for lung function tests on account of a history of breathlessness and cough.
Which statement about lung volumes is correct?
Your Answer: The tidal volume is the volume of air in the lungs after a maximum expiration
Correct Answer: The tidal volume is the volume of air drawn in and out of the lungs during normal breathing
Explanation:The tidal volume(TV) is the amount of air that moves in and out of the lungs with each respiratory cycle. In a healthy male, the usual volume is 0.5 L (,7 ml/kg body mass).
The vital capacity(VC) is the maximum amount of air that can be exhaled following maximal inspiration. The usual volume in a healthy male is 4.5 L.
The residual volume(RV) is the amount of air remaining in the lungs after maximum expiration. The usual volume in a healthy male is 1.0 L.
The inspiratory reserve volume(IRV) is the maximum amount of air that can be breathed in forcibly after normal inspiration. The usual volume in a healthy male is 3.0 L.
The expiratory reserve volume(ERV) is the volume of air that can be breathed out forcibly after normal expiration. The usual volume in a healthy male is 1.0 L.
Total lung capacity(TLC) is the volume of air the lungs can accommodate. TLC = RV+VC. The usual volume in a healthy male is 5.5 L.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 70
Correct
-
Regarding calcium channel blockers, which of the following statements is CORRECT:
Your Answer: Calcium channel blockers inhibit L-type voltage-sensitive calcium channels in arterial smooth muscle causing vasodilation.
Explanation:Calcium channel blockers inhibit L-type voltage-sensitive calcium channels in arterial smooth muscle, causing relaxation and vasodilation (reduction in peripheral vascular resistance). They also block calcium channels within the myocardium and conducting tissues of the heart which produces a negative inotropic effect by reducing calcium influx during the plateau phase of the action potential.
They have a variety of uses, including:
Hypertension
Angina
Atrial fibrillation
Migraine
Calcium channel blockers have been found to be moderately useful in the prevention of migraines. The best evidence is for this is with verapamil. This may be due to the prevention of the arteriolar constriction that is associated with migraine. They are commonly used for this elsewhere in the world but are not currently licensed for this use in the UK.
The following are common side effects of all calcium-channel blockers:
Abdominal pain
Dizziness
Drowsiness
Flushing
Headache
Nausea and vomiting
Palpitations
Peripheral oedema
Skin reactions
Tachycardia
Verapamil is highly negatively inotropic and reduces cardiac output, slows the heart rate and may impair atrioventricular conduction. It may precipitate heart failure, exacerbate conduction disorders, and cause hypotension at high doses and should not be used with beta-blockers. Nifedipine has less myocardial effects than verapamil and has no antiarrhythmic properties but has more influence on the vessels. Nimodipine is used solely for the prevention and treatment of vascular spasm following aneurysmal subarachnoid haemorrhage. -
This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 71
Incorrect
-
Which of the following best describes the main sites of constriction of the ureters:
Your Answer: At the ureteropelvic junction and where the ureter is crossed by the ductus deferens
Correct Answer: At the ureteropelvic junction, at the pelvic brim and where the ureters enter the bladder
Explanation:At three points along their course, the ureters are constricted denoting the most likely areas for renal calculi to lodge:the first point is at the ureteropelvic junction (where the renal pelvis becomes continuous with the ureter)the second point is where the ureter crosses the common iliac vessels at the pelvic brimthe third point is at the vesicoureteric junction (where the ureter enters the wall of the bladder)
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 72
Incorrect
-
As a response to low blood pressure, the baroreceptor reflex will facilitate vasoconstriction by activating which receptor?
Your Answer: Beta1
Correct Answer: Alpha1
Explanation:The rate of baroreceptor firing slows down when blood pressure falls too low. This causes an increase in sympathetic stimulation of the heart, resulting in an increase in cardiac output. It also causes vasoconstriction by activating alpha 1 receptors in smooth muscle, which causes sympathetic stimulation of peripheral vessels.
Alpha2 receptors can be found in both the brain and the peripheral nervous system. They control sympathetic outflow in the brain stem.
Beta1 receptors, which are found on the cell membrane of cardiac muscle cells, stimulate heart rate and myocardial contractility. The smooth muscle cell membrane contains beta2 receptors, which promote smooth muscle relaxation in the lungs causing bronchodilation, GI tract, and peripheral blood vessels.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 73
Correct
-
A patient presents to ED with heartburn for which they already take regular antacids. Which of the following drugs can be affected if taken with antacids:
Your Answer: Digoxin
Explanation:Antacids should preferably not be taken at the same time as other drugs since they may affect absorption. When antacids are taken with acidic drugs (e.g. digoxin, phenytoin, chlorpromazine, isoniazid) they cause the absorption of the acidic drugs to be decreased, which causes low blood concentrations of the drugs, which ultimately results in reduced effects of the drugs. Antacids taken with drugs such as pseudoephedrine and levodopa increase absorption of the drugs and can cause toxicity/adverse events due to increased blood levels of the drugs. Antacids that contain magnesium trisilicate and magnesium hydroxide when taken with some other medications (such as tetracycline) will bind to the drugs, and reduce their absorption and effects.
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This question is part of the following fields:
- Gastrointestinal
- Pharmacology
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Question 74
Incorrect
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In patients who are not at risk of hypercapnic respiratory failure but are requiring oxygen, the oxygen saturations should be maintained at which of the following?
Your Answer: 92 - 96%
Correct Answer: 94 - 98%
Explanation:Oxygen saturation should be 94 – 98% in most acutely ill patients with a normal or low arterial carbon dioxide (PaCO2). In some clinical situations, however, like cardiac arrest and carbon monoxide poisoning, it is more appropriate to aim for the highest possible oxygen saturation until the patient is stable.
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 75
Incorrect
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Regarding Campylobacter gastroenteritis, which of the following statements is INCORRECT:
Your Answer: It is associated with the subsequent development of Reiter's syndrome.
Correct Answer: Infection usually requires antibiotic treatment.
Explanation:Campylobacter jejuni is the primary human pathogen, typically causing dysentery (bloody diarrhoea illness) following ingestion of contaminated meat, especially poultry. Infection is typically self-limiting and does not require antibiotic therapy. Campylobacter gastroenteritis is associated with the immune-mediated complications of Guillain-Barre syndrome, reactive arthritis and Reiter’s syndrome.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 76
Correct
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Regarding the glomerular filtration barrier, which of the following statements is CORRECT:
Your Answer: The main factor determining whether a substance is filtered or not is molecular weight.
Explanation:Molecular weight is the main factor in determining whether a substance is filtered or not – molecules < 7 kDa in molecular weight are filtered freely e.g. glucose, amino acids, urea, ions but larger molecules are increasingly restricted up to 70 kDa, above which filtration is insignificant. Negatively charged molecules are further restricted, as they are repelled by negative charges, particularly in the basement membrane. Albumin has a molecular weight of 69 kDa and is negatively charged, thus only very small amounts are filtered (and all of the filtered albumin is reabsorbed in the proximal tubule), whereas small molecules such as ions, glucose, amino acids and urea pass the filter without hindrance. This means that ultrafiltrate is virtually protein free, but otherwise has an identical composition of that of plasma. The epithelial lining of the Bowman's capsule consists of a single layer of cells called podocytes. The glomerular capillary endothelium is perforated by pores (fenestrations) which allow plasma components with a molecular weight of < 70 kDa to pass freely.
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This question is part of the following fields:
- Physiology
- Renal
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Question 77
Correct
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A patient suffers an injury to his thigh that damages the nerve that innervates pectineus.
Which of the following nerves has been damaged in this case? Select ONE answer only.Your Answer: Femoral nerve
Explanation:Pectineus is innervated by the femoral nerve. It may also receive a branch from the obturator nerve.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 78
Incorrect
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Which of the following comprises a negative feedback mechanism?
Your Answer: Detectors, attenuators, comparators, a 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 79
Incorrect
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Compression of this nerve can cause weakness in the left leg while walking and thigh adduction weakness at the hip joint.
Your Answer: Superior gluteal nerve
Correct Answer: Obturator nerve
Explanation:The obturator nerve is a sensory and motor nerve that emerges from the lumbar plexus and innervates the thigh.
This nerve supplies motor innervation to the medial compartment of the thigh, making it necessary for thigh adduction.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 80
Incorrect
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A 55-year-old woman with a known history of bronchiectasis has lung function testing carried out and is found to have significant airways obstruction.
Which of the following lung volumes or capacities is LEAST likely to be decreased in this case? Select ONE answer only.Your Answer: Inspiratory capacity
Correct Answer: Functional residual capacity
Explanation:Obstructive lung disorders are characterised by airway obstruction. Many obstructive diseases of the lung result from narrowing of the smaller bronchi and larger bronchioles, often because of excessive contraction of the smooth muscle itself.
In obstructive lung disease, FEV1is reduced to <80% of normal and FVC is usually reduced but to a lesser extent than FEV1. The FEV1/FVC ratio is reduced to <0.7.
Types of obstructive lung disorders include:
Chronic obstructive pulmonary disease (COPD)
Asthma
Bronchiectasis
The following table outlines the effects of obstructive lung disease on the various lung volumes and capacities:
Increased by obstructive lung disease
Decreased in obstructive lung disease
Total lung capacity (TLC)
Residual volume (RV)
Functional residual capacity (FRC) Residual volume/total lung capacity (RV/TLC) ratio
Vital capacity (VC)
Inspiratory capacity (IC)
Inspiratory reserve volume (IRV) Expiratory reserve volume (ERV)
According to the latestNICE guidelines(link is external), airflow obstruction is defined as follows:
Mild airflow obstruction = an FEV1of >80% in the presence of symptoms
Moderate airflow obstruction = FEV1of 50-79%
Severe airflow obstruction = FEV1of 30-49%
Very severe airflow obstruction = FEV1<30%. -
This question is part of the following fields:
- Physiology
- Respiratory Physiology
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SESSION STATS - PERFORMANCE PER SPECIALTY
