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Question 1
Correct
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A 25 year old man has sustained a fracture to the surgical neck of the humerus after falling from his bike. Examination suggests an axillary nerve injury. The clinical features expected to be seen in this patient are:
Your Answer: Weakness of shoulder abduction
Explanation:Axillary nerve injury results in:
1. weakness of arm abduction (paralysis of deltoid),
2. weakness of lateral rotation of the arm (paralysis of teres minor)
3. loss of sensation over the regimental badge area. -
This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 2
Correct
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Which of these immunoglobulin molecules can cross the placenta?
Your Answer: IgG
Explanation:An important mechanism that provides protection to the foetus is placental transfer of maternal IgG antibodies while his/her humoral response is inefficient. The only antibody class that significantly crosses the human placenta is IgG.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 3
Correct
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Which of the following neurotransmitter and receptor combinations is present at the neuromuscular junction:
Your Answer: Acetylcholine acting at nicotinic receptors
Explanation:At the neuromuscular junction, acetylcholine is released from the prejunctional membrane which acts on cholinergic nicotinic receptors on the postjunctional membrane.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 4
Correct
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You review a sick patient in resus who has been prescribed mannitol as part of his treatment protocol.
Which SINGLE statement regarding mannitol is true?Your Answer: It is irritant to veins and causes phlebitis
Explanation: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).
Mannitol is primarily used to reduce the pressure and volume of cerebrospinal fluid (CSF). It decreases the volume of CSF by:
Decreasing the rate of CSF formation,and;
Withdrawing extracellular fluid from the brain across the BBB
Other uses of mannitol include:
Short-term management of glaucoma
Treatment of rhabdomyolysis
Preserve renal function in peri-operative jaundiced patients
To initiate diuresis in transplanted kidneys
Bowel preparation prior to colorectal procedures
The recommended dose of mannitol for the reduction of CSF pressure/cerebral oedema is 0.25-2g/kg as an intravenous infusion over 30-60 minutes. This can be repeated 1-2 times after 4-8 hours if needed.
Circulatory overload and rebound increases in intracranial pressure may occur following the use of mannitol. It is irritant to tissues and veins and can cause inflammation and phlebitis.
Mannitol causes an expansion of the extracellular fluid space, which may worsen congestive cardiac failure. Contraindications to the use of mannitol include:
Anuria
Intracranial bleeding (except during craniotomy)
Severe cardiac failure
Severe dehydration
Severe pulmonary oedema -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 5
Correct
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A 29 year old man presents to ED followed an alleged assault whilst out drinking. He received blunt trauma to his right axilla. He is complaining of difficulty abducting his right arm above the level of his shoulder, and on inspection, the inferior angle of his right scapula protrudes more than that of his left scapula. Which of the following nerves has most likely been affected:
Your Answer: Long thoracic nerve
Explanation:Damage to the long thoracic nerve results in weakness/paralysis of the serratus anterior muscle causing difficulty abducting the upper limb above 90 degrees and giving a ‘winged ‘ scapula appearance where the medial border, particularly the inferior angle, of the scapula moves laterally and posteriorly away from the thoracic wall (this becomes more pronounced if the patient presses the upper limb against a wall).
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 6
Correct
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Which of the following clinical features is most suggestive of a lesion of the temporal lobe:
Your Answer: Receptive dysphasia
Explanation:Damage to the Wernicke’s speech area in the temporal lobe can result in a receptive dysphasia. Hemispatial neglect is most likely to occur in a lesion of the parietal lobe. Homonymous hemianopia is most likely to occur in a lesion of the occipital lobe. Expressive dysphasia is most likely to occur in a lesion of the Broca speech area in the frontal lobe. Conjugate eye deviation towards the side of the lesion is most likely to occur in a lesion of the frontal lobe.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 7
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: Tibial 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. -
This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 8
Correct
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In the extrinsic pathway of the coagulation cascade, the tenase complex is:
Your Answer: Factor VIIa-tissue factor complex
Explanation:The extrinsic pathway for initiating the formation of prothrombin activator begins with a traumatized vascular wall or traumatized extravascular tissues that come in contact with the blood. Exposed and activated by vascular injury, with plasma factor VII. The extrinsic tenase complex, factor VIIa-tissue factor complex, activates factor X to factor Xa.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 9
Correct
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A 70-year-old man has a resting tremor, rigidity, bradykinesia, and a shuffling gait. Parkinson's disease is caused by one of the following mechanisms:
Your Answer: Loss of dopaminergic neurons in the substantia nigra
Explanation:Parkinson’s disease (PD) is one of the most common neurologic disorders, affecting approximately 1% of individuals older than 60 years and causing progressive disability that can be slowed but not halted, by treatment. The 2 major neuropathologic findings in Parkinson’s disease are loss of pigmented dopaminergic neurons of the substantia nigra pars compacta and the presence of Lewy bodies and Lewy neurites. See the images below.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 10
Correct
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Regarding the abductor digiti minimi, which of the following statements is false?
Your Answer: It assists with flexion of the fifth finger at the middle phalanx
Explanation:Abductor digiti minimi is a short intrinsic muscle of the hand. It belongs to the group of muscles collectively called hypothenar muscles due to their acting on the 5th finger. Besides abductor digiti minimi, other hypothenar muscles include flexor digiti minimi brevis and opponens digiti minimi.
The main function of abductor digiti minimi involves abduction of the 5th finger, as well as flexion of its proximal phalanx. Along with other hypothenar muscles, this muscle forms the hypothenar eminence on the medial side of the palm.
Like other hypothenar muscles, abductor digiti minimi receives nervous supply from the deep branch of the ulnar nerve, derived from root values C8 and T1.
Abductor digiti minimi receives arterial blood supply from the palmar branch of ulnar artery, palmar digital artery, as well as branches of the ulnar side of the superficial palmar arch. The venous blood from the muscle is drained via the venous networks of the palm into the deep veins of the arm (vv. ulnares).
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 11
Correct
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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: 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 12
Correct
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Regarding airway resistance, which of the following statements is INCORRECT:
Your Answer: In the lower respiratory tract, airway resistance is mostly determined by the smallest bronchioles.
Explanation:Airway resistance is primarily determined by the airway radius according to Poiseuille’s law, and whether the flow is laminar or turbulent. The major site of airway resistance is the medium-sized bronchi. The smallest airways would seem to offer the highest resistance, but they do not because of their branching parallel arrangement.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 13
Correct
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A 20-year-old male who is a known patient of sickle cell disease presents to the Emergency Room with a sustained erection that is extremely painful.
Out of the following clinical syndromes, which one does this patient most likely have?Your Answer: Priapism
Explanation:Sickling of red blood cells can lead to several different clinical syndromes. If the sickling occurs in the corpora cavernosa, it can lead to a sustained, painful erection of the penis, referred to as priapism. One of the complications is long-term impotence. It is important to seek a urological opinion immediately in this case, but in the interim, treat with perineal ice packs and walk up and down the stairs.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 14
Correct
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You examine a 79-year-old woman who has had hypertension and atrial fibrillation in the past. Her most recent blood tests show that she has severe renal impairment.
Which medication adjustments should you make in this patient's case?Your Answer: Reduce dose of digoxin
Explanation:Digoxin is excreted through the kidneys, and impaired renal function can lead to elevated digoxin levels and toxicity.
The patient’s digoxin dose should be reduced in this case, and their digoxin level and electrolytes should be closely monitored. -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 15
Correct
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A man suffered from a back injury due to a fall from a ladder. Significant bruising was found to be overlying his latissimus dorsi muscle.
Which of the following statements regarding the latissimus dorsi muscle is considered correct?Your Answer: It raises the body towards the arm during climbing
Explanation:The latissimus dorsi muscle is a broad, flat muscle that occupies the majority of the lower posterior thorax. The muscle’s primary function is of the upper extremity but is also considered to be a respiratory accessory muscle.
Latissimus dorsi is a climbing muscle. With the arms fixed above the head, it can raise the trunk upwards, together with the help of pectoralis major.
Functionally, the latissimus dorsi muscle belongs to the muscles of the scapular motion. This muscle is able to pull the inferior angle of the scapula in various directions, producing movements on the shoulder joint (internal rotation, adduction and extension of the arm). It is innervated by the thoracodorsal nerve (C6 – C8) from the posterior cord of the brachial plexus, which enters the muscle on its deep surface.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 16
Incorrect
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When treating diabetic ketoacidosis (DKA), which of the following should be given if the systolic blood pressure is initially less than 90 mmHg:
Your Answer: 1 L sodium chloride 0.9% intravenous infusion over 10 - 15 minutes
Correct Answer: 500 mL sodium chloride 0.9% intravenous infusion over 10 - 15 minutes
Explanation:If SBP is less than 90 mmHg , 500 mL sodium chloride 0.9 percent should be administered intravenously over 10–15 minutes, and repeated if SBP remains less than 90 mmHg. When SBP is greater than 90 mmHg, sodium chloride infusion must be maintained at a rate that replaces the deficit.
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This question is part of the following fields:
- Endocrine
- Pharmacology
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Question 17
Incorrect
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A patient presents with severe vomiting. They take a maintenance dose of 12.5 mg of prednisolone daily for their COPD. They are unable to swallow or keep down tablets at present, and you plan on converting them to IV hydrocortisone.
What dose of hydrocortisone is equivalent to this dose of prednisolone? Select ONE answer only.Your Answer: 25 mg
Correct Answer: 50 mg
Explanation:Prednisolone is four times more potent than hydrocortisone, and therefore, a dose of 12.5 mg would be equivalent to 50 mg of hydrocortisone.
The following table summarises the relative potency of the main corticosteroids compared with hydrocortisone:
Corticosteroid
Potency relative to hydrocortisone
Prednisolone
4 times more potent
Triamcinolone
5 times more potent
Methylprednisolone
5 times more potent
Dexamethasone
25 times more potent -
This question is part of the following fields:
- Endocrine Pharmacology
- Pharmacology
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Question 18
Correct
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A 68-year-old man with multiple myeloma presents with complaints of abdominal pain and malaise. A series of blood tests is done and his calcium level is 2.96 mmol/l.
What effect will this blood test result have on gastric secretions?
Your Answer: Stimulate the release of gastrin
Explanation:Hypercalcaemia stimulates the release of gastrin from the G-cells in the pyloric antrum of the stomach, the duodenum and the pancreas.
Gastrin is also released in response to:
Stomach distension
Vagal stimulation
The presence of amino acids.Gastrin release is inhibited by the presence of acid and somatostatin.
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This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 19
Correct
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A foot drop is a sign of damage to which of the following nerves?
Your Answer: Deep fibular nerve
Explanation:The deep fibular nerve was previously referred to as the anterior tibial nerve.
It starts at the common fibular nerve bifurcation, between the fibula and the proximal part of the fibularis longus. Damage to this nerve can cause foot drop or loss of dorsiflexion since this nerve controls the anterior leg muscles.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 20
Correct
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A 58-year-old woman presents with symptoms of increase in weight, proximal muscular weakening and withering, easy bruising, and acne. You notice that she has a full, plethoric aspect to her face, as well as significant supraclavicular fat pads, when you examine her. She has previously been diagnosed with Cushing's syndrome.
Cushing's syndrome is most commonly caused by which of the following?Your Answer: Iatrogenic administration of corticosteroids
Explanation:Cushing’s syndrome is a group of symptoms and signs brought on by long-term exposure to high amounts of endogenous or exogenous glucocorticoids. Cushing’s syndrome affects about 10-15 persons per million, and it is more common in those who have had a history of obesity, hypertension, or diabetes.
Iatrogenic corticosteroid injection is the most prevalent cause of Cushing’s syndrome. Cushing’s illness is the second most prevalent cause of Cushing’s syndrome. Cushing’s disease is distinct from Cushing’s syndrome in that it refers to a single cause of the illness, a pituitary adenoma that secretes high quantities of ACTH, which raises cortisol levels.
Cushing’s syndrome has several endogenous sources, including:
Cushing’s disease is caused by a pituitary adenoma.
Adrenal adenoma Ectopic corticotropin syndrome, e.g. small cell cancer of the lung
Adrenal carcinoma is a cancer of the adrenal gland.
Hyperplasia of the adrenal glands -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 21
Correct
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You have been called to review a patient and his management in the resuscitation room. A very sick patient has been started on mannitol in his treatment protocol.
Out of the following, what is NOT an FDA-recognized indication for the use of mannitol?
Your Answer: Congestive cardiac failure
Explanation:Mannitol is the most widely used osmotic diuretic that is most commonly used to reduce cerebral oedema and intracranial pressure.
Mannitol has four FDA approved uses clinically:
1. Reduction of intracranial pressure and brain mass
2. reduce intraocular pressure if this is not achievable by other means
3. promote diuresis for acute renal failure to prevent or treat the oliguric phase before irreversible damage
4. promote diuresis to promote the excretion of toxic substances, materials, and metabolitesIt can be used in rhabdomyolysis-induced renal failure, especially in crush injuries. Mannitol reduces osmotic swelling and oedema in the injured muscle cells and helps restore skeletal muscle function.
It is a low molecular weight compound and can be freely filtered at the glomerulus and not reabsorbed. This way 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).
Mannitol causes an expansion of the extracellular fluid space, which may worsen congestive cardiac failure. Contraindications to the use of mannitol include:
1. Anuria due to renal disease
2. Acute intracranial bleeding (except during craniotomy)
3. Severe cardiac failure
4. Severe dehydration
5. Severe pulmonary oedema or congestion
6. Known hypersensitivity to mannitol -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 22
Incorrect
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Which of the following accurately describes the extensor pollicis brevis muscle?
Your Answer: Its tendon forms the medial border of the anatomical snuffbox
Correct Answer: It lies on the medial side of abductor pollicis longus
Explanation:Extensor pollicis brevis is a short and slender muscle located in the posterior compartment of the forearm, extending from the posterior surface of radius to the proximal phalanx of thumb. It is one of the deep extensors of the forearm, together with supinator, abductor pollicis longus, extensor pollicis longus and extensor indicis muscles.
Extensor pollicis brevis is a deep extensor of the thumb that lies deep to extensor digitorum muscle. It sits directly medial to abductor pollicis longus and posterolateral to extensor pollicis longus muscle. Just above the wrist, extensor pollicis brevis obliquely crosses the tendons of extensor carpi radialis brevis and extensor carpi radialis longus muscles.
Extensor pollicis brevis is innervated by posterior interosseous nerve which is a continuation of a deep branch of radial nerve (root value C7 and C8).
Extensor pollicis brevis receives its blood supply by posterior interosseous artery and perforating branches from the anterior interosseous artery, which are the branches of common interosseous artery. The common interosseous artery arises immediately below the tuberosity of radius from the ulnar artery.
Together with extensor pollicis longus, extensor pollicis brevis is in charge of extension of the thumb in the first metacarpophalangeal joint. It also extends the thumb in the carpometacarpal joint of the thumb. This movement is important in the anatomy of the grip, as it enables letting go of an object. As it crosses the wrist, extensor pollicis brevis also participates in the extension and abduction of this joint.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 23
Incorrect
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You review an 83-year-old woman who has stage 5 chronic kidney disease. She has a number of electrolyte problems.
Which ONE of the following decreases the renal reabsorption of phosphate?Your Answer: Renin
Correct Answer: Parathyroid hormone
Explanation:Parathyroid hormone (PTH) is a polypeptide containing 84 amino acids. It is the principal controller of free calcium in the body.
The main actions of parathyroid hormone are:
Increases plasma calcium concentration
Decreases plasma phosphate concentration
Increases osteoclastic activity (increasing calcium and phosphate resorption from bone)
Increases renal tubular reabsorption of calcium
Decreases renal phosphate reabsorption
Increases renal conversion of 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol (via stimulation of 1-alpha hydroxylase)
Increases calcium and phosphate absorption in the small intestine (indirectly via increased 1,25-dihydroxycholecalciferol) -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 24
Incorrect
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Which of these drugs may reduce the efficacy of contraception?
Your Answer: Lamotrigine
Correct Answer: Carbamazepine
Explanation:Antiepileptic medications such as carbamazepine (Tegretol), topiramate (Topamax), and phenytoin (Dilantin) are widely known for reducing the contraceptive effectiveness of OCPs.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 25
Correct
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A 16-year old boy is brought to the emergency room after suffering a traffic accident. Upon examination, there is noted ipsilateral loss of proprioception and vibration, ipsilateral motor loss, and contralateral loss of pain and temperature sensation. A spinal cord injury is given as a diagnosis.
Which of the following is the most probable cause of this manifestation?Your Answer: Brown-Séquard syndrome
Explanation:Brown-Sequard Hemicord Syndrome consists of ipsilateral weakness (corticospinal tract) and loss of joint position and vibratory sense (posterior column), with contralateral loss of pain and temperature sense (spinothalamic tract) one or two levels below the lesion. Segmental signs, such as radicular pain, muscle atrophy, or loss of a deep tendon reflex, are unilateral. Partial forms are more common than the fully developed syndrome.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 26
Correct
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Which of the following side effects is most likely caused by erythromycin:
Your Answer: QT - prolongation
Explanation:The side effects of erythromycin include abdominal pain, anaphylaxis,
cholestatic hepatitis, confusion,
diarrhoea, dyspepsia, fever, flatulence, hallucinations, hearing loss,
headache, hypertrophic pyloric stenosis, hypotension, Interstitial
nephritis, mild allergic reactions, nausea, nervous system effects,
including seizures, pain, pruritus, pseudomembranous colitis,
QT prolongation, rash, skin eruptions, tinnitus, urticaria,
ventricular arrhythmias, ventricular tachycardia, vertigo, vomiting -
This question is part of the following fields:
- Infections
- Pharmacology
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Question 27
Correct
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The medial and lateral pterygoid muscles are innervated by which of the following nerves:
Your Answer: Mandibular division of the trigeminal nerve
Explanation:Both the medial and lateral pterygoids are innervated by the mandibular division of the trigeminal nerve.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 28
Correct
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A 62-year-old woman is brought to the Emergency Department as she is acutely unwell. Her attendants inform you that she was recently started on lithium as a mood stabilizer.
You instantly send a blood sample to check for lithium levels.
What is the usual therapeutic range for lithium?Your Answer: 0.4-0.8 mmol/l
Explanation:Lithium is the drug of choice for recurrent bipolar illness but should be carefully monitored as it has a very low therapeutic index. The normal therapeutic range is 0.4-0.8 mmol/l.
The lower end of the range is usually the target for the elderly and as maintenance therapy. Toxicity is usually seen at levels >1.5 mmol/l. Samples should be taken 12 hours after the dose, and levels should be checked one week after starting therapy and one week after every change in dosage.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 29
Correct
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Regarding gas gangrene, which of the following statements is CORRECT:
Your Answer: Infection is characterised by rapidly spreading tissue myonecrosis with crepitus.
Explanation:Gas gangrene usually occurs within 3 days of injury, and is characterised by pain, rapidly spreading oedema, myositis, necrosis, palpable crepitus and systemic toxicity. Diagnosis is clinical and laboratory confirmation should not delay urgent surgical intervention. Hyperbaric oxygen therapy can be considered in addition to surgery and antibiotic therapy, to stop toxin production and inhibit bacteria from replicating and spreading (as Clostridium spp. are obligate anaerobes).
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 30
Correct
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A patient presents to your clinic with fever of unknown origin. His blood results shows a markedly elevated C-Reactive Protein (CRP) level.
Which of these is responsible for mediating the release of CRP?
Your Answer: IL-6
Explanation:C-reactive protein (CRP) is an acute phase protein produced by the liver hepatocytes. Its production is regulated by cytokines, particularly interleukin 6 (IL-6) and it can be measured in the serum as a nonspecific marker of inflammation.
Although a high CRP suggest an acute infection or inflammation, it does not identify the cause or location of infection.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 31
Correct
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A 40-year-old woman presents with retrosternal central chest pain that she has been complaining about for the past two days. Upon deep inspiration and while lying flat, the pain worsens but relieved by sitting forwards. The pain radiates to both of her shoulders. The result of her ECG shows widespread concave ST-elevation and PR depression. A diagnosis of pericarditis is suspected.
Which of the following nerves is responsible for the pattern of her pain?Your Answer: Phrenic nerve
Explanation:Pericarditis is inflammation of the pericardial sac and is the most common pathologic process involving the pericardium. Frequently, pericardial inflammation can be accompanied by increased fluid accumulation within the pericardial sac forming a pericardial effusion, which may be serous, hemorrhagic or purulent depending on aetiology.
The classic presentation is with chest pain that is central, severe, pleuritic (worse on deep inspiration) and positional (improved by sitting up and leaning forward). The pain may also be radiating and may involve the ridges of the trapezius muscle if the phrenic nerve is inflamed as it traverses the pericardium.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 32
Correct
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A 23-year-old male presents to his family physician with the complaint of repeated episodes of abdominal pain and the passage of dark coloured urine every morning. He also reports increasing fatigue over the past several months. On examination, there are raised, painful red nodules over the skin of the back. Laboratory workup shows haemolytic anaemia, leukopenia and thrombocytopenia.
Which one of the following disorders is this patient most likely to have?Your Answer: Paroxysmal nocturnal haemoglobinuria
Explanation:Paroxysmal nocturnal haemoglobinuria is an acquired genetic disorder that causes a decrease in red blood cells due to a membrane defect that allows increased complement binding to RBCs, causing haemolysis. Patients complain of dark-coloured urine first in the morning due to haemoglobinuria secondary to lysis of red blood cells overnight.
Thrombosis occurs, which affects hepatic, abdominal, cerebral and subdermal veins. Thrombosis of hepatic veins can lead to Budd-Chiari syndrome, thrombosis of subdermal veins can lead to painful nodules on the skin, and thrombosis of cerebral vessels can lead to stroke. The presence of dark urine in the morning only and at no other time differentiates this condition from other conditions.
Multiple myeloma would present with bone pain, signs of radiculopathy if there were nerve root compression and a history of repeated infections.
Patients with Non-Hodgkin Lymphoma would complain of enlarged lymph nodes, fatigue, fever, weight loss and a history of repeated infections.
Acute lymphoblastic leukaemia presents more commonly in children than in adults. The patient would complain of bone pain, and on examination, there would be hepatosplenomegaly.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 33
Correct
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What is the mechanism of action of penicillin antibiotics:
Your Answer: Inhibition of bacterial cell wall synthesis
Explanation:Penicillins and the other ß-lactam antibiotics are bactericidal. They produce their antimicrobial action by preventing cross-linkage between the linear peptidoglycan polymer chains that make up the bacterial cell wall. They, therefore, inhibit cell wall synthesis.
The integrity of the ß-lactam ring is essential for antimicrobial activity. Many bacteria (including most Staphylococci) are resistant to benzylpenicillin and phenoxymethylpenicillin because they produce enzymes (penicillinases, ß-lactamases) that open the ß-lactam ring. -
This question is part of the following fields:
- Infections
- Pharmacology
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Question 34
Correct
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A 7-year old boy is referred to the Paediatrics Department due to slurred speech. Upon further examination, the attending physician noted the presence of dysdiadochokinesia, intention tremors, and nystagmus. An MRI is taken, which revealed a brain tumour.
Which of the following options is the most probable diagnosis given the clinical features of the patient?Your Answer: Astrocytoma of cerebellum
Explanation:Pilocytic astrocytoma (PCA), previously known as cystic cerebellar astrocytoma or juvenile pilocytic astrocytoma, was first described in 1931 by Harvey Cushing, based on a case series of cerebellar astrocytomas; though he never used these terms but rather described a spongioblastoma. They are low-grade, and usually well-circumscribed tumours, which tend to occur in young patients. By the World Health Organization (WHO) classification of central nervous system tumours, they are considered grade I gliomas and have a good prognosis.
PCA most commonly occurs in the cerebellum but can also occur in the optic pathway, hypothalamus, and brainstem. They can also occur in the cerebral hemispheres, although this tends to be the case in young adults. Presentation and treatment vary for PCA in other locations. Glial cells include astrocytes, oligodendrocytes, ependymal cells, and microglia. Astrocytic tumours arise from astrocytes and are the most common tumour of glial origin. The WHO 2016 categorized these tumours as either diffuse gliomas or other astrocytic tumours. Diffuse gliomas include grade II and III diffuse astrocytomas, grade IV glioblastoma, and diffuse gliomas of childhood. The other astrocytic tumours group include PCA, pleomorphic xanthoastrocytoma, subependymal giant cell astrocytoma, and anaplastic pleomorphic xanthoastrocytoma.
PCA can present with symptoms secondary to the posterior fossa mass effect. This may include obstructive hydrocephalus, with resultant headache, nausea and vomiting, and papilledema. If hydrocephalus occurs before the fusion of the cranial sutures (<18-months-of-age), then an increase in head circumference will likely occur. Lesions of the cerebellar hemisphere result in peripheral ataxia, dysmetria, intention tremor, nystagmus, and dysarthria. In contrast, lesions of the vermis cause a broad-based gait, truncal ataxia, and titubation. Posterior fossa lesions can also cause cranial nerve palsies. Diplopia may occur due to abducens palsy from the stretching of the nerve. They may also have blurred vision due to papilledema. Seizures are rare with posterior fossa lesions.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 35
Incorrect
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Which of the following is NOT a side effect of phenytoin:
Your Answer: Acne and hirsutism
Correct Answer: Ototoxicity
Explanation:Adverse effects of phenytoin include:
Nausea and vomiting
Drowsiness, lethargy, and loss of concentration
Headache, dizziness, tremor, nystagmus and ataxia
Gum enlargement or overgrowth
Coarsening of facial features, acne and hirsutism
Skin rashes
Blood disorders -
This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 36
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 37
Correct
-
Adenosine has a half-life of approximately:
Your Answer: 8 - 10 seconds
Explanation:Adenosine stimulates A1-adenosine receptors and opens acetylcholine sensitive K+ channels, increasing K+ efflux. This hyperpolarises the cell membrane in the atrioventricular node and, by inhibiting the calcium channels, slows conduction in the AVN. As it has a very short duration of action (half-life only about 8 – 10 seconds), most side effects are short lived.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 38
Correct
-
You review a 56-year-old man who has recently been prescribed antibiotics for a chest infection. He suffers from COPD and is currently prescribed salbutamol and Seretide inhalers, and Phyllocontin continus. Since starting the antibiotics, he has been experiencing nausea, vomiting and abdominal pain.
Which of the following antibiotics is he MOST LIKELY to have been prescribed for his chest infection? Select ONE answer only .Your Answer: Levofloxacin
Explanation:Phyllocontin continus contains aminophylline (a mixture of theophylline and ethylenediamine), a bronchodilator used in the management of COPD and asthma.
This patient is exhibiting symptoms of theophylline toxicity, which may have been triggered by the prescription of the antibiotic. Quinolone antibiotics, such as ciprofloxacin and levofloxacin, and macrolide antibiotics, such as erythromycin, increase the plasma concentration of theophyllines and can lead to toxicity.
The drugs that commonly affect the half-life and the plasma concentration of theophylline are summarised in the table below:
Drugs increasing plasma concentration of theophylline
Drugs decreasing plasma concentration of theophylline
Calcium channel blockers, e.g. Verapamil
Cimetidine
Fluconazole
Macrolides, e.g. erythromycin
Quinolones, e.g. ciprofloxacin
Methotrexate
Barbiturates
Carbamazepine
Phenobarbitol
Phenytoin (and fosphenytoin)
Rifampicin
St. John’s wort -
This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 39
Correct
-
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: 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) / r
Where:
T = Wall tension
w = Wall thickness
r = The radius
A 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 solution
Poiseuille’s law is used to calculate volume of flow rate in laminar flow
Darcy’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 40
Correct
-
Where is angiotensin I primarily converted to angiotensin II:
Your Answer: Lungs
Explanation:Angiotensin I is converted to angiotensin II by the removal of two C-terminal residues by the enzyme angiotensin-converting enzyme (ACE). This primarily occurs in the lungs, although it does also occur to a lesser degree in endothelial cells and renal epithelial cells.
The main actions of angiotensin II are:
Vasoconstriction of vascular smooth muscle (resulting in increased blood pressure)
Vasoconstriction of the efferent arteriole of the glomerulus (resulting in an increased filtration fraction and preserved glomerular filtration rate)
Stimulation of aldosterone release from the zona glomerulosa of the adrenal cortex
Stimulation of anti-diuretic hormone (vasopressin) release from the posterior pituitary
Stimulation of thirst via the hypothalamus
Acts on the Na+/H+ exchanger in the proximal tubule of the kidney to stimulate Na+reabsorption and H+excretion -
This question is part of the following fields:
- Physiology
- Renal
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Question 41
Correct
-
A 26-year-old woman is currently 9 weeks pregnant. Upon interview and history taking, she mentioned that she visited a friend whose child had just been diagnosed with slapped cheek disease.
If the mother contracts an illness during pregnancy, which among the following is not known to cause fetal abnormalities?Your Answer: Hepatitis A
Explanation:Hepatitis A usually doesn’t pose a special risk to a pregnant woman or her baby. Maternal infection doesn’t result in birth defects, and a mother typically doesn’t transmit the infection to her baby. HAV is almost always transmitted by the faecal-oral route and is usually acquired through close personal contact or via contaminated food.
When a woman has chickenpox in the first 20 weeks of pregnancy, there is a 1 in 50 chance for the baby to develop a set of birth defects. This is called the congenital varicella syndrome. It includes scars, defects of muscle and bone, malformed and paralyzed limbs, small head size, blindness, seizures, and intellectual disability.
TORCH Syndrome refers to infection of a developing foetus or newborn by any of a group of infectious agents. “TORCH” is an acronym meaning (T)toxoplasmosis, (O)ther Agents, (R)ubella (also known as German Measles), (C)ytomegalovirus, and (H)erpes Simplex.
Infection with any of these agents may cause a constellation of similar symptoms in affected newborns. These may include fever; difficulties feeding; small areas of bleeding under the skin, causing the appearance of small reddish or purplish spots; enlargement of the liver and spleen (hepatosplenomegaly); yellowish discoloration of the skin, whites of the eyes, and mucous membranes (jaundice); hearing impairment; abnormalities of the eyes; and other symptoms and findings. -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 42
Incorrect
-
By which of the following is mean arterial pressure (MAP) primarily determined?
Your Answer: Total peripheral resistance and heart rate
Correct Answer: Total peripheral resistance and cardiac output
Explanation:Mean arterial pressure (MAP) = Cardiac output (CO) x Total peripheral resistance (TPR).
Cardiac output is dependent on the central venous pressure (CVP). CVP, in turn, is highly dependent on the blood volume.
Any alterations of any of these variables will likely change MAP. -
This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 43
Correct
-
Elevation of the mandible is produced primarily by which of the following muscles:
Your Answer: Temporalis, masseter and medial pterygoid
Explanation:Elevation of the mandible is generated by the temporalis, masseter and medial pterygoid muscles.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 44
Correct
-
A 32-year-old woman diagnosed with hyperthyroidism has her T 4 levels grossly elevated and she is started on carbimazole.
A release of which of the following from the hypothalamus is inhibited by increase in T4 levels?Your Answer: Thyrotropin-releasing hormone
Explanation:A negative feedback mechanism involving the hypothalamic-pituitary-thyroid axis controls the release of T3 and T4 into the bloodstream.
When metabolic rate is low or serum T3 and/or T4 levels are decrease, this triggers the secretion of thyrotropin-releasing hormone (TRH) from the hypothalamus.
TRH goes to the anterior pituitary gland and stimulates secretion of thyroid-stimulating hormone (TSH).
An increased serum level of T3 and T4 inhibits the release of TRH.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 45
Correct
-
A 59-year-old man presents to the emergency room with chest pain. He was recently released from the hospital after receiving abciximab during coronary angioplasty.
Which of the following is abciximab (ReoPro) mechanism of action?Your Answer: Antagonism of the glycoprotein IIb/IIIa receptor
Explanation:Abciximab (ReoPro) is a glycoprotein IIb/IIIa receptor antagonist that is a chimeric monoclonal antibody. It is primarily used during and after coronary artery procedures such as angioplasty to inhibit platelet aggregation.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 46
Correct
-
Which of the following side effects has limited the use of etomidate as an intravenous induction agent:
Your Answer: Adrenocortical suppression
Explanation:Etomidate causes the least cardiovascular depression of the intravenous induction agents, with only a small reduction in the cardiac output and blood pressure. In the past, etomidate was widely used to induce anaesthesia in the shocked, elderly or cardiovascularly unstable patient. However, more recently it has become less popular as a single induction dose blocks the normal stress-induced increase in adrenal cortisol production for 4 – 8 hours, and up to 24 hours in elderly and debilitated patients. Although no increase in mortality has been identified following a single dose during induction of anaesthesia, the use of etomidate has declined due to a perceived potential morbidity.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 47
Incorrect
-
The proximal convoluted tubule (PCT) is the first part of the renal tubule and lies in the renal cortex. The bulk of reabsorption of solute occurs is the PCT and 100% of glucose is reabsorbed here.
Which of the following is the mechanism of glucose reabsorption in the PCT?Your Answer: Facilitated diffusion
Correct Answer: Secondary active transport
Explanation:Glucose reabsorption occurs exclusively in the proximal convoluted tubule by secondary active transport through the Na.Glu co-transporters, driven by the electrochemical gradient for sodium.
The co-transporters transport two sodium ions and one glucose molecule across the apical membrane, and the glucose subsequently crosses the basolateral membrane by facilitated diffusion. -
This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 48
Correct
-
Which of the following medications can block the effect of adrenaline?
Your Answer: Beta-blockers
Explanation:Beta-blockers may reduce the response to adrenaline in the treatment of anaphylactic reactions.
Noncardioselective beta-blockers in particular can antagonize the broncho dilating and cardio stimulatory effects of adrenaline by blocking beta-2 adrenergic receptors in the smooth muscles of the bronchial tree and in the heart muscles.
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 49
Correct
-
Regarding beta-thalassaemia, which of the following statements is CORRECT:
Your Answer: Beta-thalassaemia trait is associated with a raised HbA2.
Explanation:Beta-thalassaemia major is caused by a complete or almost complete failure of β-globin chain synthesis, severe imbalance of α:β-chains with deposition of α-chains in erythroblasts, ineffective erythropoiesis and extramedullary haemopoiesis. The severe anaemia becomes apparent at 3 – 6 months when the switch from γ-chain to β-chain synthesis normally occurs. Beta-thalassaemia minor is a variable syndrome, milder than thalassaemia major, with later onset and characterised by moderate hypochromic microcytic anaemia with raised haemoglobin A2. Beta-thalassaemia trait is characterised by mild hypochromic, microcytic anaemia with raised red cell count and raised haemoglobin A2.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 50
Correct
-
Salivary glands produce saliva which is mostly water, but it also contains a range of essential chemicals such as mucus, electrolytes, antibiotic agents, and enzymes.
Which of the following is a carbohydrate-digesting enzyme found in saliva?
Your Answer: Amylase
Explanation:The acinar cells of the parotid and submandibular glands release amylase. Amylase begins starch digestion before food is even eaten, and it works best at a pH of 7.4.
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This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 51
Correct
-
A 42-year-old man presented to the emergency room after an incident of slipping and falling onto his back and left hip. Upon physical examination, it was noted that he has pain on hip adduction, but normal hip flexion.
Which of the following muscles was most likely injured in this case?Your Answer: Pectineus
Explanation:The hip adductors are a group of five muscles located in the medial compartment of the thigh. These muscles are the adductor longus, adductor brevis, adductor magnus, gracilis, and pectineus.
The hip flexors consist of 5 key muscles that contribute to hip flexion: iliacus, psoas, pectineus, rectus femoris, and sartorius.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 52
Correct
-
A 4-year old boy is taken to the emergency room after a sudden onset of coughing and wheezing. Further investigation reveals that he was drawing quietly in his room, when suddenly, he became anxious and started coughing. The parents also noted that the eraser on top of the pencil was missing.
A plain radiographic chest imaging is conducted, and confirmed foreign body aspiration.
Which of the following areas in the tracheobronchial tree is the most probable location of the aspirated eraser?Your Answer: Right main bronchus
Explanation:In foreign body aspiration, the foreign body is more likely to enter the right main bronchus because it is shorter, wider and more vertical than the left main bronchus. In a patient who is standing or sitting, the foreign body tends to become lodged in the posterobasal segment of the inferior lobe of the right lung.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 53
Correct
-
Oculomotor (CN III) palsy with sparing of the pupillary reflex is most likely caused by which of the following:
Your Answer: Diabetes mellitus
Explanation:Compressive causes of CN III palsy cause early pupillary dilatation because the parasympathetic fibres run peripherally in the nerve and are easily compressed. In diabetes mellitus the lesions are ischaemic rather than compressive and therefore typically affect the central fibres resulting in pupillary sparing.
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This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
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Question 54
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 55
Correct
-
What is the main mechanism of action of dopamine as an inotropic sympathomimetic:
Your 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 56
Correct
-
You are examining the lower limbs of a 54 year old man who presented after falling from a ladder at home. During your neurological assessment you note a weakness of hip flexion. Which of the following nerves is the most important for flexion of the thigh at the hip joint:
Your Answer: Femoral nerve
Explanation:Flexion of the thigh at the hip joint is produced by the sartorius, psoas major, iliacus and pectineus muscles, assisted by the rectus femoris muscle, all innervated by the femoral nerve (except for the psoas major, innervated by the anterior rami of L1 – 3).
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 57
Incorrect
-
Fracture of the medial epicondyle would result to the following, except
Your Answer: Weakness of adduction of the fingers
Correct Answer: Weakness of abduction of the thumb
Explanation:Thumb abduction is mediated by the abductor pollicis longus and brevis, which are innervated by the radial and median nerves, respectively.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 58
Incorrect
-
Since the fluid that enters the loop of Henle is isotonic, what is its estimated osmolality?
Your Answer: 400 mOsm
Correct Answer: 300 mOsm
Explanation:The loop of Henle connects the proximal tubule to the distal convoluted tubule and lies parallel to the collecting ducts. It is consists of three major segments, the thin descending limb, the thin ascending limb, and the thick ascending limb.
The segments are differentiated based on structure, anatomic location, and function. The main action of the loop of Henle is to recover water and sodium chloride from urine. The liquid entering the loop of Henle is a solution of salt, urea, and other substances traversed along by the proximal convoluted tubule, from which most of the dissolved components are needed by the body, particularly glucose, amino acids, and sodium bicarbonate that have been reabsorbed into the blood.
This fluid is isotonic. Isotonic fluids generally have an osmolality ranging from 270 to 310 mOsm/L. With the fluid that enters the loop of Henle, it is estimated to be 300 mOsm/L. However, after passing the loop, fluid entering the distal tubule is hypotonic to plasma since it has been diluted during its passage.
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 59
Correct
-
A 36-year-old man presented to the emergency room after an incident of slipping and falling onto his back and left hip. Upon physical examination, it was noted that he has pain on hip extension, but normal hip abduction.
Which of the following muscles was most likely injured in this case?Your Answer: Gluteus maximus
Explanation:The primary hip extensors are the gluteus maximus and the hamstrings such as the long head of the biceps femoris, the semitendinosus, and the semimembranosus. The extensor head of the adductor magnus is also considered a primary hip extensor.
The hip abductor muscle group is located on the lateral thigh. The primary hip abductor muscles include the gluteus medius, gluteus minimus, and tensor fasciae latae.
The secondary hip abductors include the piriformis, sartorius, and superior fibres of the gluteus maximus. -
This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 60
Correct
-
The following statements about leukotrienes as chemical mediators of the acute inflammatory response are all true EXCEPT?
Your Answer: They decrease vascular permeability
Explanation:Leukotrienes increases (not decrease) vascular permeability during acute inflammation.
All the other statements are correct
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 61
Correct
-
Nifedipine commonly causes which of the following adverse effects?
Your Answer: Ankle oedema
Explanation:Most common adverse effects of Nifedipine include:
Peripheral oedema (10-30%)
Dizziness (23-27%)
Flushing (23-27%)
Headache (10-23%)
Heartburn (11%)
Nausea (11%) -
This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 62
Correct
-
As a result of a cardiovascular drug she was prescribed, a 67-year-old woman develops corneal microdeposits.
Which of the following drugs is the MOST LIKELY cause?Your Answer: Amiodarone
Explanation:Corneal microdeposits are almost universally present (over 90%) in people who have been taking amiodarone for more than six months, especially at doses above 400 mg/day. Although these deposits usually cause no symptoms, about 10% of patients report seeing a ‘bluish halo.’ This goes away once the treatment is stopped, and it rarely causes vision problems.
Other effects of amiodarone on the eye are much rarer, occurring in only 1-2 percent of patients:
Optic neuropathy is a condition that affects the eyes.
Non-arteritic anterior ischaemic optic neuropathy (N-AION)
Swelling of the optic disc -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 63
Correct
-
A 23-year-old man is discovered to have an infection from Helicobacter pylori.
Which of the following types of cancer is mostly associated with Helicobacter pylori infection?Your Answer: Gastric cancer
Explanation:H. pylori is recognized as a major cause of type B gastritis, a chronic condition formerly associated primarily with stress and chemical irritants. In addition, the strong association between long-term H. pylori infection and gastric cancer has raised more questions regarding the clinical significance of this organism. There is speculation that long-term H. pylori infection resulting in chronic gastritis is an important risk factor for gastric carcinoma resulting in H. pylori being classified as a carcinogen.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 64
Correct
-
A 24-year-old male presents to the Emergency Department with a three-day history of high-grade fever, headache and rash along with neck stiffness. On examination, Kernig's sign is positive, and you note a petechial rash over the trunk and limbs. Her vital signs show tachycardia and hypotension. Based on these findings, you diagnose sepsis secondary to meningitis.
Which one of the following definitions of sepsis is currently accepted?Your Answer: Life-threatening organ dysfunction caused by a dysregulated host response to infection
Explanation:In 2016 the SOFA guideline was introduced, also called the Sepsis-related Organ Failure Assessment, to make a sepsis diagnosis easier and prevent mortality.
According to this guideline, sepsis was defined as a life-threatening organ dysfunction due to a dysregulated host response to infection.
Septic shock was defined as a subset of sepsis in which the circulatory and metabolic abnormalities would lead to a greater risk of mortality than sepsis alone. Patients with septic shock would be clinically identified by a need for vasopressors to maintain MAP greater than 65 mmHg and serum lactate greater than two mmol/L.
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This question is part of the following fields:
- Pathology
- Pathology Of Infections
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Question 65
Correct
-
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: 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 66
Incorrect
-
Which of the following data types does a pain-scoring system represent?
Your Answer: Discrete
Correct Answer: Ordinal
Explanation:Pain scoring systems are processes for assessing pain and the severity of illnesses that have been scientifically designed and tested. An example of ordinal categorical data is a pain scoring system.
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 67
Correct
-
Regarding aspirin at analgesic doses, which of the following statements is CORRECT:
Your Answer: It is contraindicated in patients with severe heart failure.
Explanation:Aspirin (at analgesic doses) is contraindicated in severe heart failure. Aspirin irreversibly inhibits cyclooxygenase (COX) enzymes resulting in decreased production of prostaglandins (which can lead to irritation of the gastric mucosa). The analgesic dose is greater than the antiplatelet dose, and taken orally it has a duration of action of about 4 hours. Clinical features of salicylate toxicity in overdose include hyperventilation, tinnitus, deafness, vasodilatation, and sweating.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 68
Correct
-
A patient with a diagnosis of HIV presents with a fever, sore throat, and general malaise and you are concerned the patient may have an AIDS defining illness.
Which one of these, according to the CDC definition, would mean a patient infected with HIV has AIDS?
Your Answer: CD4 T-cell percentage of total lymphocytes of less than 15%
Explanation:According to the CDC definition, a patient co-infected with HIV can be diagnosed with AIDS if he or she has:
A CD4 T-cell count of less than 200 cells/mm3 or;
A CD4 T-cell percentage of total lymphocytes of less than 15% or;
An AIDS defining infectionA Streptococcal throat infection is not an AIDS defining infection.
A normal CD4 count ranges from 500-1000 cells/mm3. A CD4 (not CD8) count of less than 200 cells/mm3 is AIDS defining.
The CD4 count can vary from day to day and depending upon the time that the blood test is taken. It can also be affected by the presence of other infections or illnesses. Treatment with anti-retroviral therapy should be considered at CD4 count of less than 350 cells/mm3.
Serum concentrations of the p24 antigen (the viral protein that makes up most of the core of the HIV) 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.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 69
Correct
-
Which of the following study designs is considered the most appropriate to safely determine whether an association exists between a well-established, commonly used, anti-hypertensive medication and causing type II diabetes mellitus?
Your Answer: A meta-analysis
Explanation:Evidence-based medicine may be defined as the systematic, quantitative, preferentially experimental approach to obtaining and using medical information. Therefore, meta-analysis, a statistical procedure that integrates the results of several independent studies, plays a central role in evidence-based medicine.
Meta-analysis is a quantitative, formal, epidemiological study design used to systematically assess previous research studies to derive conclusions about that body of research. Outcomes from a meta-analysis may include a more precise estimate of the effect of treatment or risk factor for disease, or other outcomes, than any individual study contributing to the pooled analysis.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 70
Incorrect
-
A 19-year-old woman presents with dysuria and vaginal discharge. A swab was taken for culture. Culture results showed the presence of Neisseria gonorrhoeae infection. Treatment of azithromycin and doxycycline was started.
Which of the following statements is considered correct regarding Neisseria gonorrhoeae?Your Answer: Vaginal discharge is present in around 90% of infected women
Correct Answer: Throat swabs can be used for diagnosis
Explanation:Neisseria gonorrhoeae is a Gram-negative diplococcus that causes gonorrhoea. Gonorrhoea is an acute pyogenic infection of nonciliated columnar and transitional epithelium; infection can be established at any site where these cells are found. Gonococcal infections are primarily acquired by sexual contact and occur primarily in the urethra, endocervix, anal canal, pharynx, and conjunctiva.
In men, acute urethritis, usually resulting in purulent discharge and dysuria (painful urination), is the most common manifestation. The endocervix is the most common site of infection in women. Symptoms of infection, when present, include dysuria, cervical discharge, and lower abdominal pain. Some cases in women may be asymptomatic leading to complications such as pelvic inflammatory disease. Blood-borne dissemination occurs in less than 1% of all infections, resulting in purulent arthritis and rarely septicaemia. Fever and a rash on the extremities can also be present. Other conditions associated with N. gonorrhoeae include anorectal and oropharyngeal infections. Infections in these sites are more common in men who have sex with men but can also occur in women.
Pharyngitis is the chief complaint in symptomatic oropharyngeal infections, whereas discharge, rectal pain, or bloody stools may be seen in rectal gonorrhoea. Approximately 30% to 60% of women with genital gonorrhoea have concurrent rectal infection. Newborns can acquire ophthalmia neonatorum, a gonococcal eye infection, during vaginal delivery through an infected birth canal.
Specimens collected for the recovery of N. gonorrhoeae may come from genital sources or from other sites, such as the rectum, pharynx, and joint
fluid. According to the 2010 STD Treatment guidelines, cephalosporins (e.g., ceftriaxone, cefixime) are currently recommended treatments. -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 71
Correct
-
You are about to give an antimuscarinic agent to a 55 year-old male patient. Which of the following conditions will make you with stop the administration, since it is a contraindication to antimuscarinic agents?
Your Answer: Prostatic enlargement
Explanation:Antimuscarinic medications may impair the contractility of bladder smooth muscle, resulting in acute urine retention in men with BPH, and should be avoided or used with caution.
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This question is part of the following fields:
- Gastrointestinal
- Pharmacology
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Question 72
Correct
-
A patient noticed ankle swelling and has passed very little urine over the past 24 hours. He also has nausea and vomiting, reduced urine output and his blood results reveal a sudden rise in his creatinine levels over the past 48 hours. You make a diagnosis of acute kidney injury (AKI).
Which one of these is a prerenal cause of AKI?
Your Answer: Cardiac failure
Explanation:The causes of AKI can be divided into pre-renal, intrinsic renal and post-renal causes. Majority of AKI developing in the community is due to a pre-renal causes (90% of cases).
Pre-renal causes: Haemorrhage, severe vomiting or diarrhoea, burns, cardiac failure, liver cirrhosis, nephrotic syndrome, hypotension, severe cardiac failure, NSAIDs, COX-2 inhibitors, ACE inhibitors or ARBs, Abdominal aortic aneurysm, renal artery stenosis, hepatorenal syndrome,
Intrinsic (renal) causes:
Eclampsia, glomerulonephritis, thrombosis, haemolytic-uraemic syndrome, acute tubular necrosis (ATN), acute interstitial nephritis, drugs ( NSAIDs), infection or autoimmune diseases, vasculitis, polyarteritis nodosa, thrombotic microangiopathy, cholesterol emboli, renal vein thrombosis, malignant hypertensionPost-renal causes: Renal stones, Blood clot, Papillary necrosis, Urethral stricture, Prostatic hypertrophy or malignancy, Bladder tumour, Radiation fibrosis, Pelvic malignancy, Retroperitoneal fibrosis
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 73
Correct
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A patient presents with haemoptysis, weight loss, and night sweats. You suspect he may have tuberculosis. He works at an asylum seeker hostel, and has not received a BCG vaccination. In which of the following patient groups would the BCG vaccine be safe to administer?
Your Answer: The patient is asplenic
Explanation:Persons with chronic diseases. Persons with chronic renal disease or undergoing dialysis, and those with hyposplenism or asplenia, may receive BCG vaccine if indicated.
Only 2 absolute contraindications apply to all vaccines:
- anaphylaxis following a previous dose of the relevant vaccine
- anaphylaxis following any component of the relevant vaccine
2 further contraindications apply to live vaccines (both parenteral and oral):
- People who are significantly immunocompromised should not receive live vaccines. This is regardless of whether the immunocompromising condition is caused by disease or treatment.
- Pregnant women should not receive live vaccines, in general. Women should be advised not to become pregnant within 28 days of receiving a live vaccine.
Use of live vaccines in people who are immunocompromised:
People who are immunocomprised are at risk of adverse events or vaccine-related disease if they receive a live vaccine.Live vaccines include:
BCG (bacille Calmette–Guérin) vaccine
oral cholera vaccine (Vaxchora)
Some Japanese encephalitis virus vaccines
MMR (measles-mumps-rubella) vaccine
rotavirus vaccine
oral typhoid vaccine
varicella vaccine
yellow fever vaccine
zoster vaccine (Zostavax) -
This question is part of the following fields:
- Immunological Products & Vaccines
- Pharmacology
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Question 74
Correct
-
Regarding cellular respiration, which of the following statements is CORRECT:
Your 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 75
Correct
-
Regarding paracetamol, which of the following statements is CORRECT:
Your Answer: It has anti-pyretic action.
Explanation:Paracetamol is a non-opioid analgesic, similar in efficacy to aspirin, with antipyretic properties but no anti-inflammatory properties. It is well absorbed orally and does not cause gastric irritation. Paracetamol is a suitable first-line choice for most people with mild-to-moderate pain, and for combination therapy.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 76
Incorrect
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A 20-year-old male patient lives in a travelling community and has never received any vaccinations. He presents to you with fever.
Which of these statements concerning indications and contraindications for vaccination is FALSE?
Your Answer: Vaccination should be avoided during times of acute febrile illness
Correct Answer: Premature infants should have the their immunisation schedule adjusted for gestational age
Explanation:All vaccines are contraindicated in individuals with:
A confirmed anaphylactic reaction to a previous dose of the vaccine or a vaccine containing the same antigens.
A confirmed anaphylactic reaction to a component in the vaccine e.g. neomycinLive attenuated vaccines are contraindicated in pregnancy except in cases where risk of infection is more than the risks of vaccination.
During times of acute febrile illness, vaccination should be avoided.
12 weeks should elapse after a dose of human immunoglobulin before a live vaccine is administered.
The normal times recommended for immunization of full-term babies should also be applied to premature infants and correction for gestational age should NOT be implemented.
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 77
Incorrect
-
Regarding Clostridium perfringens, which of the following statements is CORRECT:
Your Answer: It has endotoxin-mediated effects in tissue causing severe tissue damage.
Correct Answer: It can cause exotoxin-mediated food poisoning.
Explanation:Clostridium perfringens is an obligate anaerobe and has exotoxin mediated effects. It is the most common cause of gas gangrene. C. perfringens is also implicated in food poisoning, cellulitis, enteritis necrotican (life-threatening infection involving ischaemic necrosis of the jejunum), and rarely, CNS infections such as meningitis and encephalitis.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 78
Incorrect
-
A 29-year-old volunteer returns from a recent trip to the middle east with profuse watery diarrhoea. You make a diagnosis of cholera and organize a hospital admission for rehydration with intravenous fluids.
What is the mechanism of action of cholera toxin?
Your Answer: Inhibition of adenyl cyclase
Correct Answer: ADP-ribosylation of the G regulatory protein
Explanation:Cholera is caused by Vibrio cholerae, a motile, Gram-negative, curved bacillus. It is transmitted through water and food (especially seafood) and is primarily a disease seen in developing countries where there is poor sanitation and lack of safe water supplies.
The cholera toxin leads to stimulation of adenyl cyclase, ADP-ribosylation of the G regulatory protein, inactivation of GTPase leading to active outpouring of NaCl.
The cholera toxin consists of an A (the toxin) and B subunit. The B subunit attaches to the gut mucosa and presents the A subunit to the cell. The toxin stimulates adenyl cyclase by irreversible ADP-ribosylation of the GTP binding domain of adenyl cyclase leading to the opening of chloride channels resulting in an outpouring of NaCl and water into the lumen of the gut and causing secretory diarrhoea.
Incubation period is between 2 and 5 days, but can be as short as just a few hours.
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 79
Correct
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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 80
Correct
-
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 81
Correct
-
Which of the following movements is controlled by the pectoralis major muscle?
Your Answer: Flexion, adduction and medial rotation of the humerus
Explanation:The pectoralis major is a muscle that runs across the top of the chest and connects to a ridge on the back of the humerus (the bone of the upper arm).
Adduction, or lowering, of the arm (opposed to the deltoideus muscle) and rotation of the arm forward around the axis of the body are two of its main functions.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 82
Incorrect
-
All of the following statements are considered true regarding L'Abbe plots, except:
Your Answer: Data on the upper left side of the plot indicates that experimental treatment is better than the control
Correct Answer: Treatment group results are plotted on the horizontal axis
Explanation:A L’Abbé plot is a scatter plot with the risk in the control group on the x-axis and the risk in the experimental group on the y-axis. It can be used to evaluate heterogeneity in meta-analysis. Furthermore, this plot can aid to choose a summary measure (odds ratio, risk ratio, risk difference) that will result in more consistent results.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 83
Correct
-
Regarding atracurium, which of the following statements is CORRECT:
Your 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 84
Correct
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A 59-year-old otherwise well woman presents with a history of polydipsia and polyuria. There is a past history of kidney stones, and blood tests done reveal the following:
Na: 147 mmol/L (135-147 mmol/L)
K: 4.0 mmol/L (3.5-5.5 mmol/L)
Urea: 7.3 mmol/L (2.0-6.6 mmol/L)
Creatinine: 126 mmol/L (75-125 mmol/L)
Fasting blood glucose: 5.0 mmol/L (3.4-5.5 mmol/L)
Corrected calcium: 3.21 mmol/L (2.05-2.60 mmol/L)
Phosphate: 0.70 mmol/L (0.8-1.4 mmol/L)
Parathyroid hormone: 189 ng/L (10-60 ng/L)
The most likely diagnosis is?Your Answer: Primary hyperparathyroidism
Explanation:Primary hyperparathyroidism the commonest cause of hypercalcaemia. It is commonest in women aged 50 to 60.
The commonest cause of primary hyperparathyroidism is a solitary adenoma of the parathyroid gland (approximately 85% of cases).Primary hyperparathyroidism may present with features of hypercalcaemia such as polyuria, polydipsia, renal stones, bone and joint pain, constipation, and psychiatric disorders.
In primary Hyperparathyroidism:
PTH is elevated
Calcium is elevated
Phosphate is loweredIn secondary Hyperparathyroidism:
PTH is elevated
Calcium is low or low-normal
Phosphate is raised in CRFIn tertiary Hyperparathyroidism:
PTH is elevated
Calcium is elevated
Phosphate is lowered in CRF -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 85
Correct
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A 77 year old lady presents to ED with her left leg shortened and externally rotated following slipping and falling on a wet bathroom floor. There is an intracapsular fracture of the neck of femur seen on imaging studies. She is at risk of avascular necrosis of the head of femur.
This is caused by lack of blood supply from which of these arteries?
Your Answer: Medial circumflex artery
Explanation:The primary blood supply to the head of the femur is from branches of the medial femoral circumflex artery.
The superior and inferior gluteal arteries supply the hip joint but not the head of femur.
The lateral circumflex artery anastomoses with the medial femoral circumflex artery and assists in supplying the head of femur.
The obturator artery is an important source of blood supply in children up to about 8 years. It gives rise to the artery of the head of femur which runs in the ligamentum teres and is insufficient to supply the head of femur in adults.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 86
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 87
Correct
-
Glucagon may be used as an antidote for overdose with which of the following:
Your Answer: Beta blockers
Explanation:Glucagon is a peptide hormone that is produced and secreted by alpha cells of the islets of Langerhans, which are located in the endocrine portion of the pancreas. The main physiological role of glucagon is to stimulate hepatic glucose output, thereby leading to increases in glycaemia. It provides the major counter-regulatory mechanism to insulin in maintaining glucose homeostasis.
Hypoglycaemia is the principal stimulus for the secretion of glucagon but may also be used as an antidote in beta-blocker overdose and in anaphylaxis in patients on beta-blockers that fail to respond to adrenaline.
Glucagon then causes:
Glycogenolysis
Gluconeogenesis
Lipolysis in adipose tissue
The secretion of glucagon is also stimulated by:
Adrenaline
Cholecystokinin
Arginine
Alanine
Acetylcholine
The secretion of glucagon is inhibited by:
Insulin
Somatostatin
Increased free fatty acids
Increased urea productionGlycolysis is the metabolic pathway that converts glucose into pyruvate. The free energy released by this process is used to form ATP and NADH. Glycolysis is inhibited by glucagon, and glycolysis and gluconeogenesis are reciprocally regulated so that when one cell pathway is activated, the other is inactive and vice versa.
Glucagon has a minor effect of enhancing lipolysis in adipose tissue. Lipolysis is the breakdown of lipids and involves the hydrolysis of triglycerides into glycerol and free fatty acids. It makes fatty acids available for oxidation.
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This question is part of the following fields:
- Endocrine
- Pharmacology
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Question 88
Correct
-
Regarding basophils, which of the following statements is INCORRECT:
Your Answer: They are the second most common type of granulocyte.
Explanation:Basophils are only occasionally seen in normal peripheral blood comprising < 1% of circulating white cells. However, they are the largest type of granulocyte. They have many dark cytoplasmic granules which overlie the nucleus and contain heparin and histamine. They have immunoglobulin E (IgE) attachment sites and their degranulation is associated with histamine release. Basophils are very similar in both appearance and function to mast cells.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 89
Correct
-
The resting membrane potential of a neurone is usually about:
Your Answer: -70 mV
Explanation:In most neurones the resting potential has a value of approximately -70 mV. The threshold potential is generally around -55 mV. Initial depolarisation occurs as a result of a Na+influx through ligand-gated Na+channels. Action potential is an all or nothing response; because the size of the action potential is constant, the intensity of the stimulus is coded by the frequency of firing of a neuron. Repolarisation occurs primarily due to K+efflux.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 90
Correct
-
The patients listed below have been diagnosed with a variety of ailments.
In which of the following situations would aspirin be an effective treatment option?Your Answer: A 36-year-old with an acute migraine (dose of 900-1000 mg)
Explanation:A study published in the Cochrane Database of Systematic Reviews in 2010 found that a single 1000-mg dose of aspirin is effective in treating acute migraine. It was discovered that 24 percent of aspirin users were pain-free after two hours, compared to 11 percent of placebo users. Because the BNF recommends a maximum dose of 900 mg for analgesia and most non-proprietary aspirin comes in a dose of 300 mg, a dose of 900 mg is frequently prescribed in the UK.
Because aspirin is not recommended for children under the age of 16 due to the risk of Reye’s syndrome, it would be inappropriate to give it to the 12-year-old with the viral URTI.
For uncomplicated dental pain, aspirin is an acceptable option, but not for patients who are taking warfarin. The combination of aspirin’s antiplatelet action and warfarin’s anticoagulation properties puts the patient at high risk of bleeding. Furthermore, aspirin can deplete the therapeutic levels of warfarin by displacing it from plasma proteins. It would be better to use another NSAID or analgesic.
In gout, aspirin should be avoided because it reduces urate clearance in the urine and interferes with the action of uricosuric agents. Naproxen, diclofenac, and indomethacin are better options.
Although aspirin is useful for inflammatory pains, the dose of aspirin required for an adequate analgesic effect in severe pain is associated with significant side effects. Naproxen would be a better first-line treatment option.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 91
Correct
-
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 92
Correct
-
Which of the following best describes an intention to treat analysis:
Your Answer: All patients are included in the analysis according to the group into which they were randomised even if they are withdrawn from the study.
Explanation:An intention to treat (ITT) analysis is one in which all patients are included in the analysis, classified according to the group into which they were randomised, even if they were withdrawn from the study and did not actually receive the treatment, did not comply with treatment or drop-out. Intention to treat analysis is a more reliable estimate of true treatment effectiveness by replicating what happens in the ‘real world’ (e.g. noncompliance and protocol violations commonly affect therapies).
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This question is part of the following fields:
- Evidence Based Medicine
- Study Methodology
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Question 93
Correct
-
Which of the following antibiotics may be used for malaria prophylaxis:
Your Answer: Doxycycline
Explanation:Doxycycline may be used for malaria prophylaxis and as an adjunct to quinine in the treatment of Plasmodium falciparum malaria.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 94
Correct
-
A 70-year-old patient diagnosed with Cushing's syndrome and has a history of weight gain, hypertension, and easy bruising.
Which of these assertions about Cushing's syndrome is correct?Your Answer: Diagnosis can be confirmed by a dexamethasone suppression test
Explanation:Cushing’s syndrome is a group of symptoms and signs brought on by long-term exposure to high amounts of endogenous or exogenous glucocorticoids.
Iatrogenic corticosteroid injection is the most prevalent cause of Cushing’s syndrome. Cushing’s illness is the second most prevalent cause of Cushing’s syndrome. Cushing’s disease is distinct from Cushing’s syndrome in that it refers to a single cause of the illness, a pituitary adenoma that secretes high quantities of ACTH, which raises cortisol levels.
Because cortisol enhances the vasoconstrictive impact of endogenous adrenaline, patients with Cushing’s syndrome are usually hypertensive.
Hyperglycaemia (due to insulin resistance) rather than hypoglycaemia is a common symptom.
Cortisol levels fluctuate throughout the day, with the greatest levels occurring around 0900 hours and the lowest occurring at 2400 hrs during sleep. The diurnal swing of cortisol levels is lost in Cushing’s syndrome, and levels are greater throughout the 24-hour period. In the morning, levels may be normal, but they may be high at night-time, when they are generally repressed.A dexamethasone suppression test or a 24-hour urine free cortisol collection can both be used to establish the existence of Cushing’s syndrome.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 95
Correct
-
All of the following statements are considered true regarding nominal variables, except:
Your Answer: The central tendency of a nominal variable is given by its median
Explanation:A nominal variable is a type of variable that is used to name, label or categorize particular attributes that are being measured. It takes qualitative values representing different categories, and there is no intrinsic ordering of these categories.
A nominal variable is one of the 2 types of categorical variables and is the simplest among all the measurement variables. Some examples of nominal variables include gender, name, phone, etc.A nominal variable is qualitative, which means numbers are used here only to categorize or identify objects. They can also take quantitative values. However, these quantitative values do not have numeric properties. That is, arithmetic operations cannot be performed on them. If the variable is nominal, the mode is the only measure of central tendency to use.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 96
Correct
-
Swelling of the lips, tongue, and face is observed in a 59-year-old African-American woman. In the emergency room, she is given intramuscular adrenaline, but her symptoms do not improve. Her GP recently started her on a new medication.
Which of the following drugs is most likely to have caused her symptoms?Your Answer: Ramipril
Explanation:Angiotensin-converting enzyme (ACE) inhibitors are the most common cause of drug-induced angioedema in the United Kingdom and the United States, owing to their widespread use.
Angioedema is caused by ACE inhibitors in 0.1 to 0.7 percent of patients, with data indicating a persistent and relatively constant risk year after year. People of African descent have a five-fold higher chance of contracting the disease.
Swelling of the lips, tongue, or face is the most common symptom, but another symptom is episodic abdominal pain due to intestinal angioedema. Itching and urticaria are noticeably absent.
The mechanism appears to be activated complement or other pro-inflammatory cytokines like prostaglandins and histamine, which cause rapid vasodilation and oedema.
Other medications that are less frequently linked to angioedema include:
Angiotensin-receptor blockers (ARBs)
Nonsteroidal anti-inflammatory drugs (NSAIDs)
Bupropion (e.g. Zyban and Wellbutrin)
Beta-lactam antibiotics
Statins
Proton pump inhibitorsThe majority of these reactions are minor and can be treated by stopping the drug and prescribing antihistamines.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 97
Correct
-
Which of the following statements about vitamin B12 absorption is TRUE:
Your Answer: On ingestion, vitamin B12 is bound to R protein which protects it from digestion in the stomach.
Explanation:The substance intrinsic factor,
essential for absorption of vitamin B12 in the ileum, is
secreted by the parietal cells along with the secretion of
hydrochloric acid. When the acid-producing parietal
cells of the stomach are destroyed, which frequently
occurs in chronic gastritis, the person develops not only
achlorhydria (lack of stomach acid secretion) but often
also pernicious anaemia because of failure of maturation
of the red blood cells in the absence of vitamin B12 stimulation of the bone marrow. -
This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 98
Correct
-
Regarding control of hospital acquired infection (HAI), which of the following statements is CORRECT:
Your Answer: Chlorhexidine is an anti-staphylococcal agent.
Explanation:Chlorhexidine is an anti-staphylococcal agent. Cleaning is the removal of foreign material from areas or objects to a point at which they are visually free from debris. Disinfection is the reduction in the number of infectious particles. Isopropyl alcohol is not effective against C. difficile spores. Autoclaving is a method of sterilisation.
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This question is part of the following fields:
- Microbiology
- Principles
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Question 99
Correct
-
Which of the following laboratory findings is NOT typical of Hodgkin lymphoma:
Your Answer: Basophilia
Explanation:Features may include:Normochromic normocytic anaemia is most common; bone marrow failure involvement is unusual in early disease, but if it occurs bone marrow failure may develop with leucoerythroblastic anaemiaOne-third of patients have a neutrophilia; eosinophilia is frequentAdvanced disease is associated with lymphopenia and loss of cell-mediated immunityPlatelet count is normal or increased in early disease and reduced in later stagesESR and CRP are usually raised (ESR is useful in monitoring disease progress)Serum LDH is raised initially in 30-40% of casesDiagnosis is made by histological examination of an excised lymph nodeThe distinctive multinucleate polypoid RS cell is central to the diagnosis of the four classic types of HL (95% of cases)
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This question is part of the following fields:
- Haematology
- Pathology
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Question 100
Correct
-
An elderly man presents with bilateral lower facial swelling around the mandible and upper neck. A CT scan of his neck was performed and the results were conclusive with Ludwig's angina.
Which of the following spaces is most likely affected based on the case presented?Your Answer: Submandibular space
Explanation:Ludwig’s angina is life-threatening cellulitis of the soft tissue involving the floor of the mouth and neck. It involves three compartments of the floor of the mouth: the sublingual, submental, and submandibular.
Ludwig’s angina usually originates as a dental infection of the second or third mandibular molars. The infection begins in the subgingival pocket and spreads to the musculature of the floor of the mouth. It progresses below the mylohyoid line, indicating that it has moved to the sublingual space. As the roots of the second and third mandibular molars lie below this line, infection of these teeth will predispose to Ludwig’s angina. The infection spreads lingually rather than buccally because the lingual aspect of the tooth socket is thinner. It initially spreads to the sublingual space and progresses to the submandibular space.
The disease is usually polymicrobial, involving oral flora, both aerobes, and anaerobes. The most common organisms are Staphylococcus, Streptococcus, Peptostreptococcus, Fusobacterium, Bacteroides, and Actinomyces.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 101
Incorrect
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A 40-year-old woman was rushed to the Emergency Department due to an anaphylactic reaction after being stung by a bee. She responded well to initial treatment but developed anaphylactic symptoms after 6 hours. Her symptoms were resolved after a further dose of adrenaline. Her family threatened legal action as they thought she had not received adequate treatment but withdrew their accusation after the attending physician explained that the woman had suffered a biphasic reaction.
What is the approximate percentage of people who suffer this type of reaction?Your Answer: 10%
Correct Answer: 20%
Explanation:Anaphylactic reactions are Type 1 hypersensitivity reactions IgE-mediated and can be potentially life-threatening if not treated promptly. There are four well-recognized patterns of anaphylaxis:
1) Uniphasic
2) Biphasic
3) Protracted
4) RefractoryBiphasic reactions occur in 20% of the population, although their mechanism is poorly understood. The symptoms of anaphylaxis recur within 4-6 hours, although they may also recur up to 72 hours later. All patients discharged from the hospital after an anaphylactic shock must:
1) Be warned to return to the hospital immediately if symptoms recur
2) Have a treatment plan in place
3) Have a follow-up appointment
4) Be considered for an adrenaline auto-injector
5) Referred to an allergy clinic -
This question is part of the following fields:
- General Pathology
- Pathology
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Question 102
Incorrect
-
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 103
Correct
-
Regarding loop diuretics, which of the following statements is INCORRECT:
Your Answer: The risk of hypokalaemia is greater with loop diuretics than with an equipotent dose of a thiazide diuretic.
Explanation:Hypokalaemia can occur with both thiazide and loop diuretics. The risk of hypokalaemia depends on the duration of action as well as the potency and is thus greater with thiazides than with an equipotent dose of a loop diuretic. Hypokalaemia is dangerous in severe cardiovascular disease and in patients also being treated with cardiac glycosides. Often the use of potassium-sparing diuretics avoids the need to take potassium supplements. In hepatic failure, hypokalaemia caused by diuretics can precipitate encephalopathy, particularly in alcoholic cirrhosis.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 104
Correct
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Question 105
Correct
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A 32-year-old woman suffers a deep wound to her thigh while she was climbing over a barbed wire fence. As a consequence of her injury, the nerve that was severed innervates the gracilis muscle.
In which of the following nerves is the gracilis muscle innervated by?Your Answer: Anterior branch of the obturator nerve
Explanation:The gracilis muscles is innervated by the anterior branch of the obturator nerve (L2-L4).
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 106
Correct
-
Which of the following muscles is least likely to be involved in forceful expiration:
Your Answer: External intercostal muscles
Explanation:Forceful expiration is primarily produced by the deeper thoracic muscles (internal and innermost intercostal muscles, subcostals and transversus thoracis) aided by contraction of the abdominal wall muscles which increase intra-abdominal pressure thus further reducing the volume of the thorax.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 107
Correct
-
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 in the Ticagrelor group.Your Answer: 0.1
Explanation:The absolute risk (AR) is the probability or chance of an event. It is computed as the number of events in treated or control groups, divided by the number of people in that group.
AR = 30/300 = 0.1
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This question is part of the following fields:
- Evidence Based Medicine
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Question 108
Incorrect
-
You examine a 78-year-old man who has been diagnosed with chronic lymphocytic leukaemia (CLL).
What is the MAIN contributory factor in this condition's immunodeficiency?Your Answer: Neutropenia
Correct Answer: Hypogammaglobulinemia
Explanation:Immunodeficiency is present in all patients with chronic lymphocytic leukaemia (CLL), though it is often mild and not clinically significant. Infections are the leading cause of death in 25-50 percent of CLL patients, with respiratory tract, skin, and urinary tract infections being the most common.
Hypogammaglobulinemia is the most common cause of immunodeficiency in CLL patients, accounting for about 85 percent of all cases.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 109
Correct
-
A 6-year-old girl is brought to the nephrology clinic by her mother due to facial oedema. Her lab workup shows proteinuria of 7 g/24 hours and serum albumin levels of 15 g/L. A diagnosis of Nephrotic Syndrome is made, and corticosteroid therapy is initiated.
Which one of the following is the most likely cause of nephrotic syndrome in this patient?Your Answer: Minimal change disease
Explanation:Minimal Change Disease is the most common cause of Nephrotic Syndrome in the paediatric population. It may be caused by NSAID use. Electron microscopy shows the fusion of foot processes while light microscopy will appear normal.
Focal segmental glomerulosclerosis causes Nephrotic Syndrome in adults. It is associated with Heroin use and HIV infection. There is a limited response to steroids, and the disease progresses to end-stage renal failure in 5-10 years.
Diabetic nephropathy occurs after a long period of diabetes due to the deposition of amyloid protein leading to a decrease in glomerular filtration.
There is no history of Hepatitis B in this patient and no symptoms of liver disease such as jaundice.
Membranous glomerulonephritis would present with features of Nephritic Syndrome. These would be oedema, haematuria; red blood cell casts in the urine and hypertension.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 110
Correct
-
What proportion of peripheral blood leukocytes are monocytes?
Your Answer: 5 - 10%
Explanation:Monocytes account for around 5 to 10% of peripheral white cells. Monocytes in peripheral blood are generally bigger than other leukocytes and feature a large central oval or indented nucleus with clumped chromatin. The abundant cytoplasm staining blue and containing numerous fine vacuoles gives the appearance of ground glass. Cytoplasmic granules are another type of granule.
Monocytes evolve from the granulocyte-macrophage progenitor to become monoblasts, promonocytes, monocytes, and tissue macrophages (in increasing order of maturity). Monocytes only stay in the bone marrow for a short time before exiting to circulate in the bloodstream for 20-40 hours before becoming macrophages.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 111
Correct
-
A 63-year-old man complains of chest pain and syncope on occasion. His heart rate is 37 beats per minute, and he has a second-degree heart block, according to his rhythm strip.
Which of the following would be the most appropriate next step in his management, according to the ALS bradycardia algorithm?Your Answer: Give atropine 500 mcg
Explanation:Atropine is used to treat bradycardia (sinus, atrial, or nodal) or AV block when the patient’s haemodynamic condition is compromised by the bradycardia.
If any of the following adverse features are present, the ALS bradycardia algorithm recommends a dose of atropine 500 mcg IV:
Shock
Syncope
Myocardial ischemia
Insufficiency of the heartIf this does not work, give additional 500 mcg doses at 3-5 minute intervals until a maximum dose of 3 mg is reached. The heart rate can be slowed paradoxically if the dose is higher than 3 mg.
The ALS bradycardia algorithm also suggests the following interim measures:
Transcutaneous pacing
Isoprenaline infusion 5 mcg/min
Adrenaline infusion 2-10 mcg/minutes
Alternative drugs (aminophylline, dopamine, glucagon, glycopyrrolate) -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 112
Correct
-
Which of the following is NOT a typical feature of lithium toxicity:
Your Answer: Miosis
Explanation:Features of toxicity include:
Increasing gastrointestinal disturbances (vomiting, diarrhoea, anorexia)
Visual disturbances
Polyuria and incontinence
Muscle weakness and tremor
Tinnitus
CNS disturbances (dizziness, confusion and drowsiness increasing to lack of coordination, restlessness, stupor)
Abnormal reflexes and myoclonus
Hypernatraemia
With severe overdosage (serum-lithium concentration > 2 mmol/L) seizures, cardiac arrhythmias (including sinoatrial block, bradycardia and first-degree heart block), blood pressure changes, electrolyte imbalance, circulatory failure, renal failure, coma and sudden death may occur. -
This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 113
Correct
-
Compliance is greater in all but which one of the following:
Your Answer: Pulmonary oedema
Explanation:Compliance changes at different lung volumes. Initially at lower lung volumes the compliance of the lung is poor and greater pressure change is required to cause a change in volume. This occurs if the lungs become collapsed for a period of time. At functional residual capacity (FRC) compliance is optimal since the elastic recoil of the lung tending towards collapse is balanced by the tendency of the chest wall to spring outwards. At higher lung volumes the compliance of the lung again becomes less as the lung becomes stiffer. At all volumes, the base of the lung has a greater compliance than the apex. Patients with emphysema have increased compliance. Compliance is affected by a person’s age, sex and height.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 114
Correct
-
Regarding acute lymphoblastic leukaemia (ALL), which of the following statements is CORRECT:
Your Answer: 75% of cases occur before the age of 6 years.
Explanation:Acute lymphoblastic leukaemia (ALL) is caused by an accumulation of lymphoblasts in the bone marrow and is the most common malignancy of childhood. The incidence of ALL is highest at 3 – 7 years, with 75% of cases occurring before the age of 6. 85% of cases are of B-cell lineage. Haematological investigations reveal a normochromic normocytic anaemia with thrombocytopenia in most cases. There is great variation in the chance of individual patients achieving a long-term cure based on a number of biological variables. Approximately 25% of children relapse after first-line therapy and need further treatment but overall 90% of children can expect to be cured. The cure rate in adults drops significantly to less than 5% over the age of 70 years.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 115
Correct
-
Red cell protein expression is induced by which of the following pathogens:
Your Answer: Plasmodium falciparum
Explanation:Plasmodium falciparum induces the expression of red cell protein, making cerebral malaria more severe. Bacteria may invade a host passively through micro traumata or macro traumata in the skin or mucosa. On the other hand, bacteria that invade
through intact mucosa first, adhere to this anatomical barrier, then actively
breach it. -
This question is part of the following fields:
- Microbiology
- Principles
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Question 116
Correct
-
A 47-year old male comes to the out-patient department for a painful, right-sided groin mass. Medical history reveals a previous appendectomy 10 years prior. On physical examination, the mass can be reduced superiorly. Also, the mass extends to the scrotum. The initial diagnosis is a hernia.
Among the types of hernia, which is the most likely diagnosis of the case above?Your Answer: Indirect inguinal hernia
Explanation:Inguinal hernias can present with an array of different symptoms. Most patients present with a bulge in the groin area, or pain in the groin. Some will describe the pain or bulge that gets worse with physical activity or coughing. Symptoms may include a burning or pinching sensation in the groin. These sensations can radiate into the scrotum or down the leg. It is important to perform a thorough physical and history to rule out other causes of groin pain. At times an inguinal hernia can present with severe pain or obstructive symptoms caused by incarceration or strangulation of the hernia sac contents. A proper physical exam is essential in the diagnosis of an inguinal hernia. Physical examination is the best way to diagnose a hernia. The exam is best performed with the patient standing. Visual inspection of the inguinal area is conducted first to rule out obvious bulges or asymmetry in groin or scrotum. Next, the examiner palpates over the groin and scrotum to detect the presence of a hernia. The palpation of the inguinal canal is completed last. The examiner palpates through the scrotum and towards the external inguinal ring. The patient is then instructed to cough or perform a Valsalva manoeuvre. If a hernia is present, the examiner will be able to palpate a bulge that moves in and out as the patient increases intra abdominal pressure through coughing or Valsalva.
Groin hernias are categorized into 2 main categories: inguinal and femoral.
Inguinal hernias are further subdivided into direct and indirect. An indirect hernia occurs when abdominal contents protrude through the internal inguinal ring and into the inguinal canal. This occurs lateral to the inferior epigastric vessels. The hernia contents may extend into the scrotum, and can be reduced superiorly then superolaterally. A direct inguinal hernia is protrusion of abdominal contents through the transversalis fascia within Hesselbach’s triangle. The borders of Hesselbach’s triangle are the inferior epigastric vessels superolaterally, the rectus sheath medially, and inguinal ligament inferiorly.
A femoral hernia is a protrusion into the femoral ring. The borders of the femoral ring are the femoral vein laterally, Cooper’s ligament posteriorly, the iliopubic tract/inguinal ligament anteriorly and lacunar ligament medially.
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This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 117
Correct
-
Cefotaxime (or ceftriaxone) is used first line for which of the following infections:
Your Answer: Blind treatment of suspected bacterial meningitis
Explanation:Cefotaxime (or ceftriaxone) are indicated first line in:
– Blind treatment of meningitis in patients > 3 months (with amoxicillin if patient > 50 years)
– Meningitis caused by meningococci
– Meningitis caused by pneumococci
– Meningitis caused by H. influenzae
– Severe or invasive salmonellosis
– Typhoid fever
– Gonorrhoea
– Gonococcal arthritis
– Haemophilus influenzae epiglottitis -
This question is part of the following fields:
- Infections
- Pharmacology
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Question 118
Correct
-
The least likely feature of anaemia is:
Your Answer: Narrow pulse pressure
Explanation:Non-specific signs of anaemia include:
1. pallor of mucous membranes or nail beds (if Hb < 90 g/L),
2. tachycardia
3. bounding pulse
4. wide pulse pressure
5. flow murmurs
6. cardiomegaly
7. signs of congestive cardiac failure (in severe cases) -
This question is part of the following fields:
- Haematology
- Pathology
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Question 119
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 120
Correct
-
Clostridium difficile primarily causes which of the following infectious diseases:
Your 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 121
Correct
-
Which of the following types of food is most commonly implicated in anaphylactic reactions:
Your Answer: Nuts
Explanation:Anaphylaxis can be triggered by any of a very broad range of triggers, but those most commonly identified include food, drugs, latex and venom. Of foods, nuts are the most common cause; muscle relaxants, antibiotics, NSAIDs and aspirin are the most commonly implicated drugs. Food is the commonest trigger in children and drugs the commonest in adults. A significant number of cases are idiopathic. Most reactions occur over several minutes; rarely, reactions may be slower in onset. The speed of onset of the reaction depends on the trigger e.g. intravenous medications will cause a more rapid onset than stings which in turn will cause a more rapid onset than ingestion of food.
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 122
Correct
-
A 56-year-old female presents at the hospital with a diabetic foot ulcer that has become infected. She has a longstanding history of type 2 diabetes mellitus and diabetic polyneuropathy. She has trouble controlling her blood sugar levels, and recently, she was converted to a new insulin regimen that includes intermediate-acting insulin.
Out of the following, which one is the intermediate-acting insulin?Your Answer: Isophane insulin
Explanation:Insulin is used mainly in type 1 diabetes, where the pancreas makes no insulin and can sometimes be prescribed in type 1 diabetes. There are different types of insulin categorized by their onset of action:
1. Intermediate-acting insulins (isophane insulin NPH):
– intermediate duration of action, designed to mimic the effect of endogenous basal insulin
– starts their action in 1 to 4 hours
– peaks in 4 to 8 hours
– dosing is usually twice a day and helps maintain blood sugar throughout the day
– Isophane insulin is a suspension of insulin with protamine2. Short-acting insulins (regular insulin)
– starts the action in 30 to 40 minutes
– peaks in 90 to 120 minutes
– duration of action is 6 to 8 hours
– taken before meals, and food is necessary within 30 minutes after its administration to avoid hypoglycaemia3. Long-acting insulins (glargine, detemir, degludec)
– start action in 1 to 2 hours
– plateau effect over 12 to 24 hours
– Dosing is usually during the night-time after meals. Their long duration of action helps in reducing the frequency of dosing throughout the day.4. Rapid-acting insulins (lispro, aspart, glulisine)
– start their action in 5 to 15 minutes
– peak in 30 minutes
– The duration of action is 3 to 5 hours
– generally used before meals and always used along with short-acting or long-acting insulins to control sugar levels throughout the day. -
This question is part of the following fields:
- Endocrine Pharmacology
- Pharmacology
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Question 123
Correct
-
Which of these cell types in the stomach releases pepsinogen?
Your 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 124
Correct
-
A 39-year-old guy comes to the emergency room with a persistent nasal bleed. You suspect the bleeding is coming from Little's area based on your examination. Which of the blood vessels listed below is most likely to be involved:
Your Answer: Sphenopalatine and superior labial arteries
Explanation:The Kiesselbach plexus is a vascular network formed by five arteries that supply oxygenated blood to the nasal septum, which refers to the wall separating the right and left sides of the nose. The five arteries that form the Kiesselbach plexus: the sphenopalatine artery, which branches from the maxillary artery originating behind the jawbone; the anterior ethmoidal artery, which branches from the ophthalmic artery behind the eye; the posterior ethmoidal artery, which also branches from the ophthalmic artery; the septal branch of the superior labial artery, which is a branch of the facial artery supplying blood to all of the superficial features of the face; and finally, the greater palatine artery, which is a terminal branch of the maxillary artery.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 125
Correct
-
Bile acids are essential for the digestion and absorption of which of the following:
Your Answer: Lipids and fat-soluble vitamins
Explanation:Bile acids are synthesised from cholesterol by hepatocyte and excreted into bile. Bile acids are essential for lipid digestion and absorption. 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. Many of the bile salts are reabsorbed unaltered, some are converted by intestinal bacteria into secondary bile acids (deoxycholic acid and lithocholic acid) and then reabsorbed and a small proportion escapes reabsorption and is excreted in the faeces.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 126
Correct
-
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. -
This question is part of the following fields:
- Haematology
- Pathology
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Question 127
Incorrect
-
External haemorrhoids may cause anal pain. When explaining to your patient why it does so, which of the following nerves will you point out as being affected?
Your Answer: Pelvic splanchnic nerve
Correct Answer: Pudendal nerve
Explanation:The pain associated with external haemorrhoids is carried by a branch of the pudendal nerve, specifically the somatic fibres (S2-S4).
It innervates the external anal sphincter and most of the skin over the perineum.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 128
Correct
-
Gastrin release from antral G-cells is inhibited by all but which one of the following:
Your Answer: Vagal stimulation
Explanation:Gastrin secretion is inhibited by:
Low gastric pH (negative feedback mechanism)
Somatostatin
Secretin
Gastric inhibitory polypeptide (GIP)
Cholecystokinin -
This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 129
Correct
-
Which of the following is NOT a typical side effect of opioid analgesics:
Your Answer: Diarrhoea
Explanation:All opioids have the potential to cause:
Gastrointestinal effects – Nausea, vomiting, constipation, difficulty with micturition (urinary retention), biliary spasm
Central nervous system effects – Sedation, euphoria, respiratory depression, miosis
Cardiovascular effects – Peripheral vasodilation, postural hypotension
Dependence and tolerance -
This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 130
Correct
-
A novel anti-tuberculosis medicine was compared to standard treatment and shown to cut the risk of death from 30 to 10 per 1000 people. How many patients would need to be treated (number need to treat (NNT)) in order to prevent 10 additional tuberculosis deaths:
Your Answer: 500
Explanation:The risk of mortality in the control group (usual therapy) minus the risk of death in the treatment group equals the absolute risk reduction (ARR) of treatment.
30/1000 minus 10/1000 = 20/1000 = 0.02NNT = 1/ARR = 1/0.02 = 50
As a result, 50 people would need to be treated in order to prevent one additional fatality, and 500 people would need to be treated in order to avoid 10 additional deaths. -
This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 131
Correct
-
Which of the following statements is correct regarding the neuronal action potential?
Your Answer: Initial depolarisation occurs as a result of a Na + influx.
Explanation:The resting potential in most neurons has a value of approximately -70 mV.
The threshold potential is generally around -55 mV.
Initial depolarisation when there is Na+influx through ligand-gated Na+channels.
Action potential is an all or nothing response. The size of the action potential is constant and so, the intensity of the stimulus is coded by the frequency of firing of a neuron.
K+efflux is responsible for repolarisation. -
This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 132
Correct
-
Which of the following is the most abundant immunoglobulin in plasma:
Your Answer: IgG
Explanation:IgA is the major Ig in secretions, particularly from the gastrointestinal tract (but also in saliva, tears, sweat and breast milk).
IgE is important for mast cell degranulation in allergic and antiparasitic response. In the allergic response, the plasma cell produces IgE-antibodies, which, like antibodies of other immunoglobulin isotypes, are capable of binding a specific allergen via its Fab portion.
IgG is the most abundant in plasma (comprising 80% of normal serum immunoglobulin) and the main circulatory Ig for the secondary immune response. -
This question is part of the following fields:
- Immune Responses
- Pathology
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Question 133
Correct
-
In which of the following would you NOT typically see a neutropaenia:
Your Answer: Asplenism
Explanation:Causes of neutropaenia:
Drug-induced (e.g. chemotherapy, chloramphenicol, co-trimoxazole, phenytoin, carbamazepine, carbimazole, furosemide, chloroquine, clozapine, some DMARDs)
Benign (racial or familial)
Cyclical
Immune (e.g. SLE, Felty’s syndrome, hypersensitivity and anaphylaxis)
Leukaemia
Infections (e.g. HIV, hepatitis, fulminant bacterial infection)
General Pancytopaenia
Hypersplenism, aplastic anaemia, malignant infiltration of bone marrow, megaloblastic anaemia, chemotherapy, myelodysplasia -
This question is part of the following fields:
- Immune Responses
- Pathology
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Question 134
Correct
-
A 67-year-old man complains of chest pain and goes to the emergency room. He takes several medications, including amiodarone.
Which of the following is amiodarone mechanism of action?Your Answer: Blocks Na + and K + channels and beta-adrenoreceptors in the heart
Explanation:Amiodarone is an anti-arrhythmic medication that can be used to treat both ventricular and atrial arrhythmias. It’s a class III anti-arrhythmic that works by blocking a variety of channels, including Na+ and K+ channels, as well as beta-adrenoreceptors. As a result, it slows conduction through the SA and AV nodes and prolongs phase 3 of the cardiac action potential (slowing repolarisation).
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 135
Correct
-
C3 deficiency leads to particular susceptibility of infection with which of the following:
Your Answer: Encapsulated bacteria
Explanation:Macrophages and neutrophils have C3b receptors and they phagocytose C3b-coated cells. C3 deficiency thus leads to increased susceptibility of infection with encapsulated organisms (e.g. S. pneumoniae, H. influenzae).The early stages of the complement cascade leading to coating of the cells with C3b can occur by two different pathways:The classical pathway usually activated by IgG or IgM coating of cellsThe alternative pathway which is more rapid and activated by IgA, endotoxin and other factors
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 136
Correct
-
Clostridium tetani causes which of the following infectious diseases:
Your Answer: Tetanus
Explanation:Clostridium tetani causes tetanus.
Scarlet fever is caused by Streptococcus pyogenes.
Toxic shock syndrome is caused by Staphylococcus aureus or Streptococcus pyogenes.
Gas gangrene is primarily caused by Clostridium perfringens.
Pseudomembranous colitis is commonly caused by Clostridium difficile. -
This question is part of the following fields:
- Microbiology
- Pathogens
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Question 137
Incorrect
-
A tumour compresses the jugular foramen of a 50-year-old patient. Compression of several nerves in the jugular foramen will result in which of the following complications?
Your Answer: Loss of sensation over the face
Correct Answer: Loss of gag reflex
Explanation:The glossopharyngeal nerve, which is responsible for the afferent pathway of the gag reflex, the vagus nerve, which is responsible for the efferent pathway of the gag reflex, and the spinal accessory nerve all exit the skull through the jugular foramen. These nerves are most frequently affected if the jugular foramen is compressed. As a result, the patient’s gag reflex is impaired.
The vestibulocochlear nerve is primarily responsible for hearing. The trigeminal nerve provides sensation in the face. The facial nerve innervates the muscles of face expression (including those responsible for closing the eye). Tongue motions are controlled mostly by the hypoglossal nerve.
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This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
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Question 138
Correct
-
Regarding acute idiopathic thrombocytopaenic purpura (ITP), which of the following statements is CORRECT:
Your Answer: Over 80% of children recover without treatment.
Explanation:Acute ITP is most common in children. In approximately 75% of cases, the episode follows vaccination or infection such as chicken pox or glandular fever. Most cases are caused by non-specific immune complex attachment to platelets. Acute ITP usually has a very sudden onset and the symptoms usually disappear in less than 6 months (often within a few weeks). It is usually a self-limiting condition and over 80% of children recover without treatment; in 5 – 10% of cases a chronic form of the disease develops.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 139
Correct
-
A 30-year-old man present to the ED with abdominal pain, nausea and vomiting. It has been present for the past two days.
Which of the following statements regarding diarrhoea and vomiting is true?
Your Answer: E.Coli can cause diarrhoea and renal failure
Explanation:Escherichia coli strain 0157 causes enterohaemorrhagic diarrhoea and can lead to renal failure, haemolytic anaemia and thrombocytopenia.
Norwalk virus is an RNA virus.
Although transmission of rotavirus is primarily through the faeco-oral route, airborne spread has been seen in some cases.
Cryptosporidium are protozoa with acid fast walls and are resistant to both chlorine treatment and conventional filtering methods.
There is no therapy effective in treating cryptosporidium diarrhoea as the protozoa is not susceptible to antibiotics.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 140
Incorrect
-
Which of the following hormones regulates Na+reabsorption in the proximal tubule:
Your Answer: Atrial natriuretic peptide
Correct Answer: Angiotensin II
Explanation:Angiotensin II increases 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 141
Correct
-
A 22-year-old man comes to the emergency department with a human bite injury to his hand received from a punch during a fight 3 hours earlier outside a bar. On closer inspection, you discover bite marks on his first and second knuckles. Which of the following is the best treatment option for this patient:
Your Answer: Oral co-amoxiclav for 7 days
Explanation:Even if there is no evidence of infection, prophylactic antibiotics should be administered for all human bite wounds that are less than 72 hours old. The first-line therapy is 7 days of co-amoxiclav. In penicillin-allergic people, metronidazole + doxycycline is an option. Streptococcus spp., Staphylococcus aureus, Haemophilus spp., Eikenella corrodens, Bacteroides spp., and other anaerobes are the most prevalent organisms found in human bites.
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This question is part of the following fields:
- Infections
- Microbiology
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Question 142
Correct
-
Which of the following nerves is most important for eversion of the foot:
Your Answer: Superficial fibular nerve
Explanation:Eversion of the foot is primarily produced by the fibularis longus and fibularis brevis, both innervated by the superficial fibular nerve. The fibularis tertius, innervated by the deep fibular nerve, also assists in this action.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 143
Correct
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What kind of function loss do you anticipate in a 22-year-old guy who had a laceration to his arm, resulting in nerve damage in the antecubital fossa?
Your Answer: Opposition of thumb
Explanation:The symptoms of median nerve injury include tingling or numbness in the forearm, thumb, and three adjacent fingers, as well as gripping weakness and the inability to move the thumb across the palm.
Because the thenar muscles and the flexor pollicis longus are paralyzed, flexion, abduction, and opposition of the thumb at the MCPJ and IPJ are gone.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 144
Correct
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A 40-year-old man has been admitted for alcohol detoxification. You are asked to review the patient's treatment chart and notice that he has been prescribed Pabrinex by one of your colleagues.
Out of the following, which vitamin is not found in Pabrinex?Your Answer: Vitamin B12
Explanation:Pabrinex is indicated in patients that require rapid therapy for severe depletion or malabsorption of water-soluble vitamins B and C, particularly in alcoholism detoxification.
Pabrinex has the following:
1. Thiamine (vitamin B1)
2. Riboflavin (vitamin B2)
3. Nicotinamide (Vitamin B3, niacin and nicotinic acid)
4. Pyridoxine (vitamin B6)
5. Ascorbic acid (vitamin C)
6. GlucoseSuspected or established Wernicke’s encephalopathy is treated by intravenous infusion of Pabrinex/ The dose is 2-3 pairs three times a day for three to five days, followed by one pair once daily for an additional three to five days or for as long as improvement continues.
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This question is part of the following fields:
- Fluids & Electrolytes
- Pharmacology
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Question 145
Correct
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Most of the lymph from vessels that drain the breast is collected in which of the following lymph nodes?
Your Answer: Axillary nodes
Explanation:Lymph is the fluid that flows through the lymphatic system.
Axillary lymph nodes are near the breasts. They are often the first location to which breast cancer spreads if it moves beyond the breast tissue. They receive approximately 75% of lymph drainage from the breast via lymphatic vessels, laterally and superiorly.
The lymph usually first drains to the anterior axillary nodes, and from here, through the central axillary, apical, and supraclavicular nodes in sequence.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 146
Incorrect
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Which of the following microbes adheres to the genital mucosa using fimbriae:
Your Answer: Chlamydia trachomatis
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 147
Correct
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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: 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. -
This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 148
Correct
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Regarding the human cell, which of the following cell organelles is responsible for the production of ATP:
Your Answer: Mitochondria
Explanation:Mitochondria are membrane-bound organelles that are responsible for the production of the cell’s supply of chemical energy. This is achieved by using molecular oxygen to utilise sugar and small fatty acid molecules to generate adenosine triphosphate (ATP). This process is known as oxidative phosphorylation and requires an enzyme called ATP synthase. ATP acts as an energy-carrying molecule and releases the energy in situations when it is required to fuel cellular processes. Mitochondria are also involved in other cellular processes, including Ca2+homeostasis and signalling. Mitochondria contain a small amount of maternal DNA.
Mitochondria have two phospholipid bilayers, an outer membrane and an inner membrane. The inner membrane is intricately folded inwards to form numerous layers called cristae. The cristae contain specialised membrane proteins that enable the mitochondria to synthesise ATP. Between the two membranes lies the intermembrane space, which stores large proteins that are required for cellular respiration. Within the inner membrane is the perimitochondrial space, which contains a jelly-like matrix. This matrix contains a large quantity of ATP synthase.
Mitochondrial disease, or mitochondrial disorder, refers to a group of disorders that affect the mitochondria. When the number or function of mitochondria in the cell are disrupted, less energy is produced and organ dysfunction results. -
This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 149
Correct
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After collapsing in his nursing home, a 70-year-old man is brought into the ER. He has diabetes mellitus and is on medication for it. An RBS of 2.0 mmol/L (3.9-5.5 mmol/L) is recorded in the ER.
Out of the following, which medication for diabetes mellitus is LEAST likely responsible for his hypoglycaemic episode?Your Answer: Metformin
Explanation:Metformin is a biguanide used as the first-line to treat type 2 diabetes mellitus. It has a good reputation as it has an extremely low risk of causing hypoglycaemia compared to the other agents for diabetes. It does not affect the insulin secreted by the pancreas or increase insulin levels. Toxicity with metformin can, however, cause lactic acidosis with associated hypoglycaemia.
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This question is part of the following fields:
- Endocrine Pharmacology
- Pharmacology
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Question 150
Correct
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A 13-year-old male presents to the Emergency Department with a heavy nosebleed. His medical record shows that he was diagnosed with Haemophilia B as a child.
What is the mode of inheritance of this disease?Your Answer: X-linked recessive
Explanation:Deficiency of Factor IX causes Haemophilia B, and like the other Haemophilia’s, it has an X-linked recessive pattern of inheritance, affecting males born to carrier mothers.
Haemophilia B is the second commonest form of haemophilia and is rarer than haemophilia A. Haemophilia B is similar to haemophilia A but is less severe. You can distinguish the two disorders by specific coagulation factor assays.
The incidence of Haemophilia B is one-fifth of that of haemophilia A.
In laboratory findings, you get prolonged APTT, normal PT and low factor IX for Haemophilia B.
There is also a variation called Leyden, in which factor IX levels are below 1% until puberty, when they rise, potentially reaching as high as 40-60% of normal. This is thought to be due to the effects of testosterone at puberty.
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This question is part of the following fields:
- Haematology
- Pathology
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SESSION STATS - PERFORMANCE PER SPECIALTY
