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Question 1
Incorrect
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Aplastic crises in sickle cell anaemia is classically precipitated by which of the following infections:
Your Answer: Cytomegalovirus
Correct Answer: Parvovirus B19
Explanation:A serious complication in sickle cell disease (SCD) is the aplastic crisis. This may be caused by infection with Parvovirus B-19 (B19V). This virus causes fifth disease, a normally benign childhood disorder associated with fever, malaise, and a mild rash. This virus infects RBC progenitors in bone marrow, resulting in impaired cell division for a few days. Healthy people experience, at most, a slight drop in hematocrit, since the half-life of normal erythrocytes in the circulation is 40-60 days. In people with SCD, however, the RBC lifespan is greatly shortened (usually 10-20 days), and a very rapid drop in Hb occurs. The condition is self-limited, with bone marrow recovery occurring in 7-10 days, followed by brisk reticulocytosis.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 2
Correct
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Regarding bile, which of the following statements is CORRECT:
Your Answer: Bile passes into the duodenum through the ampulla of Vater.
Explanation:Bile is synthesised in the liver. Bile functions to eliminate endogenous and exogenous substances from the liver, to neutralise gastric acid in the small intestine, and to emulsify fats in the small intestine and facilitate their digestion and absorption. Bile is stored and concentrated in the gallbladder. Bile passes out of the gallbladder via the cystic duct. Bile passes into the duodenum through the ampulla of Vater regulated by the sphincter of Oddi.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 3
Correct
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Question 4
Correct
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If a patient dislocated his right shoulder and has been referred to the orthopaedic outpatient department for a follow-up after a successful reduction, which of the following is the most important position for him to avoid holding his arm in until he is seen in the clinic?
Your Answer: Arm at 90 degrees to side with palm up
Explanation:The arm should be placed in a poly-sling that should be worn for about two weeks. A physiotherapist may give gentle movements for the arm to help in reducing stiffness and in relieving the pain. It is important that the patient must avoid positions that could cause re-dislocation.The most important position to avoid is the arm being held out at 90 degrees to the side with the palm facing upwards, especially if a force is being applied.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 5
Incorrect
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A 19-year-old student that has presented with a headache and a petechial rash is diagnosed with meningitis caused by Neisseria meningitidis.Which SINGLE statement regarding Neisseria meningitidis is true?
Your Answer: It is a Gram-negative rod
Correct Answer: Lipo-oligosaccharide activates complement activation and cytokine release
Explanation:Neisseria meningitidisis is a Gram-negative diplococcusc that can cause meningococcal meningitis.Carriage of Neisseria meningitidisis very common and it exists in the normal flora in the nasopharynx in 5 – 15% of adults. Actual disease only develops in a very small percentage of individuals. Infection is most common in the winter months and epidemics tend to occur about once every 10 years.Most invasive infections are caused by serotypes A, B or C. In the UK, most cases of meningococcal septicaemia are caused byNeisseria meningitidisgroup B. The vaccination programme forNeisseria meningitidisgroup C has made this type much less common. A vaccine for group B disease has now been initiated in children.The main determinant of the pathogenicity of Neisseria meningitidisis the antiphagocytic polysaccharide capsule. Meningococci cross mucosal epithelium by endocytosis and the capsule allows survival in the bloodstream. Lipo-oligosaccharide activates complement activation and cytokine release, resulting in shock and disseminated intravascular coagulation (DIC).Theclinical featuresof meningococcal meningitis include:Non-blanching rashNeck stiffnessHeadachePhotophobiaAltered mental state (drowsiness, confusion)Focal neurological deficitsSeizuresSeptic shockThe diagnosis is usually made clinically and confirmed by culture of blood, aspirate from the rash and CSF. Rapid antigen detection or nucleic acid amplification testing (NAAT) on blood and CSF are both sensitive and reliable.Due to the potentially life-threatening nature of the disease treatment should not wait for laboratory confirmation and antibiotics should be started immediately. In the hospital setting IV ceftriaxone (2 g adult; 80 mg/kg child) or IV cefotaxime (2 g adult; 80 mg/kg child) are the preferred agents. IM benzylpenicillin can be given as an alternative in the pre-hospital setting and chloramphenicol is a suitable alternative if there is a history of anaphylaxis to cephalosporins. Treatment does not eradicate carriage and the patient should be given ‘prophylaxis’ following recovery.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 6
Incorrect
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Which of the following hormones regulates Na+reabsorption in the proximal tubule:
Your Answer: Aldosterone
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 7
Incorrect
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What is the mechanism of action of penicillin antibiotics:
Your Answer: Inhibition of bacterial protein synthesis
Correct 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.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 8
Incorrect
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Regarding antiemetics, which of the following statements is INCORRECT:
Your Answer: Metoclopramide acts on the chemoreceptor trigger zone.
Correct Answer: Of the antiemetics, cyclizine is most commonly associated with acute dystonic reactions.
Explanation:Cyclizine acts by inhibiting histamine pathways and cholinergic pathways involved in transmission from the vestibular apparatus to the vomiting centre. Metoclopramide is a dopamine-receptor antagonist which acts both peripherally in the GI tract and centrally within the chemoreceptor trigger zone. Prochlorperazine is a dopamine-D2 receptor antagonist and acts centrally by blocking the chemoreceptor trigger zone. Metoclopramide and prochlorperazine are both commonly associated with extrapyramidal effects, such as acute dystonic reaction. Cyclizine may rarely cause extrapyramidal effects.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 9
Correct
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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 10
Correct
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Which of the following is the most common cause of hyperthyroidism:
Your Answer: Graves disease
Explanation:Graves disease is the most common cause of hyperthyroidism. It is an autoimmune disease in which autoantibodies against TSH receptors are produced. These antibodies bind to and stimulate these TSH receptors leading to an excess production of thyroid hormones. Therefore, the signs and symptoms of Graves disease are the same as those of hyperthyroidism, reflecting the actions of increased circulating levels of thyroid hormones: increased heat production, weight loss, increased 02 consumption and cardiac output and exophthalmos (bulging eyes, not drooping eyelids). TSH levels will be decreased (not increased) as a result of the negative feedback effect of increased T3 levels on the anterior pituitary.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 11
Correct
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During swallowing, which of the following structures primarily closes the tracheal opening:
Your Answer: Epiglottis
Explanation:The vocal cords of the larynx are stronglyapproximated, and the larynx is pulled upwardand anteriorly by the neck muscles. These actions,combined with the presence of ligaments thatprevent upward movement of the epiglottis, causethe epiglottis to swing back over the openingof the larynx. All these effects acting togetherprevent the passage of food into the nose andtrachea. Most essential is the tight approximationof the vocal cords, but the epiglottis helps toprevent food from ever getting as far as the vocalcords. Destruction of the vocal cords or of themuscles that approximate them can causestrangulation.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 12
Correct
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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 13
Correct
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Monoamine oxidase is primarily involved in the degradation of which of the following:
Your Answer: Noradrenaline
Explanation:Catecholamines are broken down extracellularly and in the liver by catechol-O-methyltransferase (COMT) and intracellularly by monoamine oxidase (MAO).
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 14
Incorrect
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Na+ is reabsorbed via the Na+/K+/2Cl-symporter in which part of the loop of Henle?
Your Answer: Thin ascending and descending limbs
Correct Answer: Thick ascending limb
Explanation:In the thick ascending limb is the part of the loop of Henle in which there is active reabsorption of Na+and Cl- ions from the tubular fluid. This occurs via the Na+/K+/2Cl-symporter on the apical membrane. This mechanism is by:1. Na+ions are transported across the basolateral membrane by Na+pumps and the Cl-ions by diffusion. 2. K+leaks back into the tubular fluid via apical ROMK K+channels which creates a positive charge. 3. This positive charge drives the reabsorption of cations (Na+, K+, Ca2+, Mg2+) through paracellular pathways. 4. Due to the thick ascending limb being impermeable to water, the tubular fluid osmolality is reduced by ion reabsorption, the interstitial fluid osmolality is increased, and an osmotic difference is created.
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This question is part of the following fields:
- Physiology
- Renal
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Question 15
Correct
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Glucagon is secreted by which of the following pancreatic cell types:
Your Answer: α cells
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:GlycogenolysisGluconeogenesisLipolysis in adipose tissueThe secretion of glucagon is also stimulated by:AdrenalineCholecystokininArginineAlanineAcetylcholineThe secretion of glucagon is inhibited by:InsulinSomatostatinIncreased free fatty acidsIncreased 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
- Physiology
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Question 16
Correct
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A 26-year-old female cuts her hand on a knife while preparing dinner but the bleeding stops within a few minutes. Which one of the following cells will be among the first to be present at the wound site to be involved in haemostasis?
Your Answer: Platelets
Explanation:Platelets are the first cells to be attracted to the wound site due to the release of the Von Willebrand factor from the damaged endothelium. Platelets, in turn, release cytokines such as platelet-derived growth factor, which will attract other inflammatory cells to the wound site.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 17
Incorrect
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An 80-year-old male has presented with chest pain characteristic of angina pectoris. Before initiating treatment with Glyceryl nitrate, you examine the patient and find a murmur. The patient reveals that he has a heart valve disorder, and you immediately put a hold on the GTN order.Which of the following valve disorders is an absolute contraindication to the use of GTN?
Your Answer: Mitral valve prolapse
Correct Answer: Mitral stenosis
Explanation:Angina pectoris is the most common symptom of ischemic heart disease and presents with chest pain relieved by rest and nitro-glycerine. Nitrates are the first-line treatment to relieve chest pain caused by angina. The commonly used nitrates are: 1. Nitro-glycerine (NTG) – angina pectoris (treatment/prophylaxis), acute coronary syndrome, heart failure, hypertension2. Isosorbide mononitrate (ISMN) – chronic angina pectoris (treatment)3. Isosorbide dinitrate (ISDN) – angina pectoris (treatment/prophylaxis)The nitrate drugs cause vasodilation via the action of nitric oxide. The contraindications to the use of nitrate are the following: 1. Allergy to nitrates2. Concomitant use of phosphodiesterases (PDE) inhibitors such as tadalafil and sildenafil3. Right ventricular infarction4. Hypertrophic cardiomyopathy5. Cardiac tamponade6. Constrictive pericarditis7. Hypotensive conditions8. Hypovolaemia9. Marked anaemia10. Mitral stenosis11. Raised intracranial pressure due to cerebral haemorrhage or head trauma12. Toxic pulmonary oedema
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 18
Incorrect
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Which of the following statements about sickle cell disease is TRUE:
Your Answer: Sickle cell is inherited in an autosomal dominant pattern.
Correct Answer: Hand-foot syndrome is frequently a first presentation of the disease.
Explanation:Hand-foot syndrome in children is typically the first symptom of the disease, produced by infarction of the metaphysis of small bones. The disease is inherited as an autosomal recessive trait. By adulthood, the spleen has usually infarcted. Infection with the B19 parvovirus is usually followed by an aplastic crisis. Thrombocytopenia is caused by splenic sequestration.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 19
Correct
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The neurotransmitter in the synaptic cleft is either eliminated or deactivated after the postsynaptic cell responds to the neurotransmitter.Which of the following enzymes catalyses the breakdown of noradrenaline?
Your Answer: Catechol-O-methyltransferase (COMT)
Explanation:The neurotransmitter in the synaptic cleft is either eliminated or deactivated after the post-synaptic cell responds to the neurotransmitter. This can be accomplished in a variety of ways:Re-uptakeBreakdownDiffusionSerotonin is an example of a neurotransmitter that is uptake. Serotonin is absorbed back into the presynaptic neuron via the serotonin transporter (SERT), which is found in the presynaptic membrane. Re-uptake neurotransmitters are either recycled by repackaging into vesicles or broken down by enzymes.Specific enzymes found in the synaptic cleft can also break down neurotransmitters. The following enzymes are examples of these enzymes:Acetylcholinesterase (AChE) catalyses the acetylcholine breakdown (ACh)The enzyme catechol-O-methyltransferase (COMT) catalyses the breakdown of catecholamines like adrenaline , dopamine and noradrenaline. The breakdown of catecholamines, as well as other monoamines like serotonin, tyramine, and tryptamine, is catalysed by monoamine oxidases (MOA).Diffusion of neurotransmitters into nearby locations can also be used to eliminate them.
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 20
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 21
Incorrect
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You've been summoned to the resuscitation area to assist a patient who is having a seizure. As part of the treatment protocol, a benzodiazepine dose is given.Which of the following statements about the use of benzodiazepines in seizures is correct?
Your Answer: Benzodiazepines have low lipid solubility
Correct Answer: Lorazepam can be given by the rectal route
Explanation:A single dose of IV benzodiazepine will terminate the seizure in 60 to 80 percent of patients who present with seizures.Because benzodiazepines are lipid-soluble, they cross the blood-brain barrier quickly. This explains their quick onset of action.As a first-line treatment, IV lorazepam should be given. If IV lorazepam is not available, IV diazepam can be used instead, and buccal midazolam can be used if intravenous access cannot be established quickly. Lorazepam can be administered via the rectal route, but it is less reliable and has a lower absorption rate and bioavailability.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 22
Correct
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Which of the following statements is correct about the extensor digitorum muscle?
Your Answer: It extends the medial four digits at the metacarpophalangeal joints
Explanation:Extensor digitorum is a long muscle located in the posterior compartment of the forearm. Together with the extensor carpi ulnaris and extensor digiti minimi, extensor carpi radialis longus and brevis as well as the brachioradialis, it belongs to the group of superficial extensors of the forearm. These muscles can be easily palpated in the lateral aspect of the posterior forearm, especially during the extension of hand when they are contracted.Extensor digitorum runs from the lateral epicondyle of humerus to the medial four phalanges of the hand. In this way, it generates the pull for the extension of the four medial fingers in their metacarpophalangeal and both interphalangeal joints. Extensor digitorum also participates in the extension of the wrist.Extensor digitorum is innervated by posterior interosseous nerve which is a continuation of a deep branch of radial nerve (root value C7 and C8).Extensor digitorum is vascularized by the branches of three different arteries: (1) posterior interosseous artery, (2) radial recurrent artery, and (3) anterior interosseous artery. Anterior and posterior interosseous arteries are the branches of the common interosseous artery that arises from the ulnar artery. The radial recurrent artery is a branch of the radial artery.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 23
Correct
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Cardiac myocytes are connected to each other by which of the following:
Your Answer: Intercalated discs
Explanation:Adjacent cardiac myocytes are connected to each other by intercalated discs. The intercalated discs provide both a structural attachment by ‘glueing’ cells together at desmosomes and an electrical contact made up of proteins called connexons, called a gap junction, which essentially creates a low-resistance pathway between cells.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 24
Incorrect
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Which of the following nerves provides sensory innervation to the anteromedial and anterosuperior aspects of the external ear?
Your Answer: Great auricular nerve
Correct Answer: Auriculotemporal nerve
Explanation:Sensory innervation to the external ear is supplied by both cranial and spinal nerves. Branches of the trigeminal, facial, and vagus nerves (CN V, VII, X) are the cranial nerve components, while the lesser occipital (C2, C3) and greater auricular (C2, C3) nerves are the spinal nerve components involved. The lateral surface of the tympanic membrane, the external auditory canal, and the external acoustic meatus are all innervated by nervus intermedius (a branch of CN VII), the auriculotemporal nerve (CN V3), and the auricular branch of the vagus nerve. The concha receives split innervation from nervus intermedius, the auricular branch of the vagus nerve, and the greater auricular (spinal) nerve. Beyond the concha, the anteromedial and anterosuperior parts of the pinna are innervated by the auriculotemporal nerve, and a portion of the lateral helix by the lesser occipital nerve. The greater auricular nerve provides innervation to the area of the pinna inferolateral to the lobule.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 25
Incorrect
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In the emergency department, a 50-year-old female appears with a lack of sensation over the front two-thirds of her tongue. Taste and salivation are both present. The patient might have damage which of her nerves?
Your Answer: Chorda tympani nerve
Correct Answer: Lingual nerve
Explanation:The lingual nerve, a branch of the mandibular nerve, transmits sensation to the anterior two-thirds of the tongue. The chorda tympani, a branch of the facial nerve, transmits taste to the front two-thirds of the tongue as well as secretomotor innervation to the submandibular and sublingual glands. As a result, any damage to the lingual nerve can cause changes in salivary secretion on the affected side, as well as a loss of taste in the anterior two-thirds of the tongue and temporary or permanent sensory changes in the anterior two-thirds of the tongue and the floor of the mouth.
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This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
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Question 26
Incorrect
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A 45-old woman is on several medications and being treated for epilepsy and bipolar disorder. In the ward rounds, you are asked to examine her in detail and discover she has a noticeable tremor. You believe that one of her medications may be responsible for this new onset tremor. Which of the following medications is least likely to be responsible for this tremor?
Your Answer: Lithium
Correct Answer: Carbamazepine
Explanation:The only medication that does not commonly cause tremors is carbamazepine.The other drugs present with the following types of tremors as a side effect to their usage:1. Sodium valproate – Postural tremor is most common, but a resting tremor can also occur. Approximately 25% of patients taking sodium valproate are found to develop a tremor within 12 months of starting therapy.2. Lithium – fine hand tremor is very commonly seen and reported in as many as 50% of patients during the first week of therapy. The tremor tends to reduce with time and is only present in around 5% of patients taking the medication two years or longer.3. Atypical antipsychotics, such as olanzapine and quetiapine – tremor and limb shakiness.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 27
Correct
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The risk of renal impairment in a patient on ACE inhibitor therapy is increased by concomitant treatment with which of the following drug classes:
Your Answer: NSAIDs
Explanation:Concomitant treatment with NSAIDs increases the risk of renal damage, and with potassium-sparing diuretics (or potassium-containing salt substitutes) increases the risk of hyperkalaemia. Hyperkalaemia and other side effects of ACE inhibitors are more common in the elderly and in those with impaired renal function and the dose may need to be reduced.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 28
Correct
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A patient sustains an injury to the proximal median nerve after falling through a glass door. Which of the following muscles would you not expect to be affected:
Your Answer: Flexor carpi ulnaris
Explanation:All of the muscles in the anterior forearm are innervated by the median nerve, except for the flexor carpi ulnaris and the medial half of the flexor digitorum profundus which are innervated by the ulnar nerve.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 29
Correct
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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 30
Correct
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The common bile duct drains into the duodenum in which of the following regions:
Your Answer: Second part of the duodenum
Explanation:As the common bile duct descends, it passes posterior to the first part of the duodenum before joining with the pancreatic duct from the pancreas, forming the hepatopancreatic ampulla (ampulla of Vater) at the major duodenal papilla, located in the second part of the duodenum. Surrounding the ampulla is the sphincter of Oddi, a collection of smooth muscle which can open to allow bile and pancreatic fluid to empty into the duodenum.
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This question is part of the following fields:
- Abdomen
- Anatomy
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