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Question 1
Correct
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Which is the primary lymphoid organ?
Your Answer: Thymus
Explanation:Lymphoid organs consist of lymph nodes, the thymus, spleen and tonsils. The thymus is the primary lymphoid organ as it is the organ in which the T cells mature.
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This question is part of the following fields:
- Immunology
- Medicine
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Question 2
Correct
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Myelin sheath in the CNS is produced by?
Your Answer: Oligodendrocytes
Explanation:CNS myelin is produced by special cells called oligodendrocytes. PNS myelin is produced by Schwann cells. The two types of myelin are chemically different, but they both perform the same function — to promote efficient transmission of a nerve impulse along the axon.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 3
Correct
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Regarding cardiac output, an increased ejection fraction results from increases in which of the following?
Your Answer: Strength of contraction without increase in muscle fiber length
Explanation:When the strength of contraction increases without an increase in fiber length, the EF increases.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 4
Correct
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Myocardial contractility is improved by:
Your Answer: Caffeine
Explanation:Caffeine and other theophyllines breakdown cAMP and have a positive ionotropic effect on the heart. Drugs like quinidine, procainamide and conditions like hypoxia and hypercapnia decreases the contractility of the heart.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 5
Incorrect
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Which of the following is a function of Vitamin C?
Your Answer: Iron transport across the enterocytes
Correct Answer: Hydroxylation of proline to hydroxyproline for collagen synthesis
Explanation:Vitamin C acts as an electron donor for eight different enzymes: Three enzymes (prolyl-3-hydroxylase, prolyl-4-hydroxylase, and lysyl hydroxylase) that are required for the hydroxylation of proline and lysine in the synthesis of collagen.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 6
Incorrect
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What does a deficiency of adenosine deaminase lead to?
Your Answer: Lesch-Nyhan syndrome
Correct Answer: SCID
Explanation:Severe combined immunodeficiency, SCID, also known as alymphocytosis, Glanzmann–Riniker syndrome, severe mixed immunodeficiency syndrome, and thymic alymphoplasia,[1] is a rare genetic disorder characterized by the disturbed development of functional T cells and B cells. Most cases of SCID are due to mutations in the gene encoding the common gamma chain (γc), a protein that is shared by the receptors for interleukins. The second most common form of SCID after X-SCID is caused by a defective enzyme, adenosine deaminase (ADA), necessary for the breakdown of purines.
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This question is part of the following fields:
- Medicine
- Metabolism
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Question 7
Incorrect
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Erythropoietin is synthesized by which cells of the nephron?
Your Answer: Afferent arteriolar cells
Correct Answer: Tubular interstitial cells
Explanation:Erythropoietin is produced by interstitial fibroblasts in the kidney in close association with peritubular capillary and proximal convoluted tubule. It is also produced in perisinusoidal cells in the liver. While liver production predominates in the fetal and perinatal period, renal production is predominant during adulthood.
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This question is part of the following fields:
- Medicine
- Renal
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Question 8
Correct
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Which inhibitor of gastric enzyme secretion is released by the presence of fat in the jejunum?
Your Answer: Peptide yy
Explanation:Peptide yy is secreted from the jejunum due to the presence of fat. It inhibits gastric acid secretion and motility.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 9
Incorrect
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What is the name of the area that indicates the site of active B lymphocyte proliferation?
Your Answer: Cortex
Correct Answer: Germinal centre
Explanation:The cortex of the lymph node consists of the lymphoid nodules and sinusoids and posses a germinal centre from which B cells proliferate.
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This question is part of the following fields:
- Immunology
- Medicine
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Question 10
Correct
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All of the following features may suggest malignant changes in a melanocytic naevi, EXCEPT?
Your Answer: Decrease in size
Explanation:Melanocytic naevi are skin tumours produced by melanocytes. They usually present in childhood but increase during puberty. The mnemonic A-B-C-D, is used by institutions to assess for suspicion of malignancy. The letters stand for asymmetry, border, colour, and diameter. If a mole starts changing in size, colour, shape or, especially, if the border of a mole develops ragged edges or becomes larger than a pencil eraser, it would be an appropriate time to consult with a physician. Other warning signs include if it begins to crust over, bleed, itch, or become inflamed.
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This question is part of the following fields:
- Dermatology
- Medicine
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Question 11
Correct
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The inverse stretch reflex causing muscle relaxation when excessive force is applied to a muscle is mediated by which sensory organ?
Your Answer: Golgi tendon organ
Explanation:Both the muscle spindle and Golgi tendon body are proprioceptors. The Golgi tendon reflex is a normal component of the reflex arc of the peripheral nervous system. In a Golgi tendon reflex, skeletal muscle contraction causes the antagonist muscle to simultaneously lengthen and relax. This reflex is also called the inverse myotatic reflex, because it is the inverse of the stretch reflex.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 12
Correct
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An 87-year-old woman had to double up her dosage of morphine 60mg into 120mg twice a day, in addition to another 10mg oral Morphine 6 times a day. What is the best method of management?
Your Answer: Subcutaneous morphine infusion
Explanation:Stable dose of Morphine is essential for chronic cases of pain that are non-malignant in origin. Using the SC route avoids having to intravenously cannulate a patient and allows for a continuous infusion of drugs over a calculated period of time providing constant dosing A significant advantage is that plasma levels of a drug are much more stable, and appropriate symptom control can be achieved without the toxic effects of the peaks and troughs resulting from episodic drug administration.
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This question is part of the following fields:
- Geriatrics
- Medicine
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Question 13
Correct
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What are the three main structures in the portal triad (portal space)?
Your Answer: Branch of hepatic artery, branch of portal vein, bile ductules
Explanation:A portal triad (also known as portal field, portal area, or portal tract) is a distinctive arrangement in the liver. It is a component of the hepatic lobule. It consists of the following five structures:
- Proper hepatic artery
- Hepatic portal vein
- Common bile duct
- Lymphatic vessels
- Branch of the vagus nerve
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This question is part of the following fields:
- Hepatobiliary
- Medicine
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Question 14
Correct
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The predominant site in the lymph node where B lymphocytes are found is:
Your Answer: Cortex
Explanation:The cortex of the lymph node consists of the lymphoid nodules and sinusoids and posses a germinal centre from which B cells proliferate. The cortex of the lymph node predominately consists of B cells.
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This question is part of the following fields:
- Immunology
- Medicine
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Question 15
Correct
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Absorption of fructose is via:
Your Answer: Facilitated diffusion
Explanation:Dietary fructose may be ingested as a monosaccharide or as a disaccharide. Sucrose is hydrolysed by sucrase to produce equal amounts of glucose and fructose and in this form, is usually completely absorbed. Fructose is mostly absorbed in the small intestine through GLUT-5 transporter mediated facilitative diffusion. This is an energy independent process.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 16
Incorrect
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Closure of the tricuspid valve is marked by which of the following features of the jugular venous waveform?
Your Answer: a wave
Correct Answer: c wave
Explanation:The jugular venous pressure (JVP) classically has three upward deflections and two downward deflections. The upward deflections are the a (atrial contraction), c (ventricular contraction and resulting bulging of tricuspid into the right atrium during isovolumetric systole) and v = venous filling. The downward deflections of the wave are the x (the atrium relaxes and the tricuspid valve moves downward) and the y descent (filling of ventricle after tricuspid opening).
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 17
Incorrect
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Synthesis of haem for haemoglobin occurs in the?
Your Answer: None of the above
Correct Answer: Mitochondria of the red blood cells
Explanation:Haemoglobin (Hb) is synthesized in a complex series of steps. The haem part is synthesized in a series of steps in the mitochondria and the cytosol of immature red blood cells, while the globin protein parts are synthesized by ribosomes in the cytosol.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 18
Incorrect
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Where is the aqueous humor normally reabsorbed?
Your Answer: Pupil
Correct Answer: Canal of schlemm
Explanation:Aqueous humor is a clear protein free fluid secreted by the ciliary body, it travels to the anterior chamber through the pupil and is absorbed through a network of trabeculae into the canal of schlemm
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This question is part of the following fields:
- Medicine
- Neurology
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Question 19
Incorrect
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The enzyme located on the brush border of the small intestine activating the proteolytic enzymes for further digestion of proteins is called?
Your Answer: Trypsin
Correct Answer: Enterokinase
Explanation:Enterokinase is a brush border enzyme of the duodenum that activates proteolytic enzymes for further digestion of proteins. Trypsinogen is converted to trypsin by the action of enterokinase. Trypsin and chymotrypsin are secreted by the pancreatic acinar cells and are enzymes that aid in protein digestion. Pepsin is secreted by chief cells of the gastric mucosa. Procarboxydase is the inactive form of carboxypeptidase which is converted to its active form by trypsin and is secreted by pancreatic acinar cells.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 20
Incorrect
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Sequence of events in formation of speech are:
Your Answer: Broca’s area---motor cortex---insula---arcuate fasciculus---Wernicke's area---speech
Correct Answer: Wernicke’s area---arcuate fasciculus---broca’s area---insula---motor cortex---speech
Explanation:Wernicke’s area is located in the categorical hemisphere or left hemisphere in about 95% of right handed individuals and 60% of left handed individuals. It is involved in the comprehension or understanding of written and spoken language. In contrast Broca’s area is involved in production of language. Firstly, the language is accessed in the Wernicke’s area and these words are sent via the arcuate fasciculus to the Broca’s area, where instructions for articulation is generated. This is then sent from Broca’s are to the motor cortex for the articulation.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 21
Incorrect
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Question 22
Incorrect
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A 26 year old male presents with right sided elbow and wrist pain and left sided knee and ankle pain that has persisted for about two weeks. He recently returned from a trip to Thailand that last for two weeks. The patient admits to having unprotected sex while on holiday. Examination reveals swelling and tenderness of tendons around joints but no inflammation of the joints. A vesiculopustular skin rash is also observed. What is the most likely cause?
Your Answer: Reactive arthritis
Correct Answer: Gonococcal arthritis
Explanation:Patients with disseminated gonococcal arthritis may present with dermatitis-arthritis syndrome (60%) of with localized septic arthritis. (40%). Arthritis-dermatitis syndrome includes the classic triad of dermatitis, tenosynovitis, and migratory polyarthritis. Gout usually involves a singe joint and does not cause vesicopustular skin rash. Reactive arthritis has ocular symptoms (conjunctivitis), urethritis, and arthritis. Fungal arthritis occurs rarely and it may occur after a surgical infection or fungal spread hematogenously. it presents with tender, red, hot and swollen joint with loss of range of motion.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 23
Correct
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Medullary chemoreceptors
Your Answer: Monitor H+ concentration of the CSF
Explanation:Central chemoreceptors of the central nervous system, located on the ventrolateral medullary surface in the vicinity of the exit of the 9th and 10th cranial nerves, are sensitive to the pH of their environment. These act to detect the changes in pH of nearby cerebral spinal fluid (CSF) that are indicative of altered oxygen or carbon dioxide concentrations available to brain tissues.
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This question is part of the following fields:
- Medicine
- Respiratory
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Question 24
Correct
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A 42 year old female with a history of SLE presents with an exacerbation of wrist pain. Which of the following markers would be the most suitable for monitoring disease activity?
Your Answer: Anti-dsDNA titres
Explanation:A high level of anti-dsDNA in the blood is strongly associated with lupus and is often significantly increased during or just prior to a flare-up. When the anti-dsDNA is positive and the person tested has other clinical signs and symptoms associated with lupus, it means that the person tested likely has lupus. This is especially true if an anti-Sm test is also positive.In the evaluation of someone with lupus nephritis, a high level (titre) of anti-dsDNA is generally associated with ongoing inflammation and damage to the kidneys.A very low level of anti-dsDNA is considered negative but does not exclude a diagnosis of lupus. Only about 65-85% of those with lupus will have anti-dsDNA.Low to moderate levels of the autoantibody may be seen with other autoimmune disorders, such as Sjögren syndrome and mixed connective tissue disease (MCTD).
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 25
Correct
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Cells responsible for completely renewing the epithelium of the intestine are located:
Your Answer: At the base of the crypts
Explanation:Epithelial cells are renewed every 4-5 days through a process of renewal and migration. Renewal relies on proliferative cells or stem cells that reside at the crypt base of the intestinal glands. Crypts are epithelial invasions into the underlying connective tissue.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 26
Correct
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Protein digestion starts in the stomach by which enzyme?
Your Answer: Pepsin
Explanation:Pepsinogen is the inactive form of pepsin which is secreted by gastric chief cells and is converted to pepsin, in the presence of gastric HCL. Pepsin is a peptidase that breaks down proteins into smaller peptides.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 27
Correct
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The process by which RNA fragments are separated by gel electrophoresis and transferred onto a membrane sheet is called:
Your Answer: Northern blotting
Explanation:Blots of the gel can be made from using nitrocellulose paper. Northern blots are produced when a fragment of radioactive DNA hybridize with RNA on a nitrocellulose blot of a gel and southern blots are produced when DNA hybrize with DNA on a nitrocellulose blot of the gel.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 28
Correct
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Which ion channel does not contribute to the myocardial action potential?
Your Answer: Chloride channel
Explanation:The upstroke in the cardiac action potential is due to opening of the sodium channels and an influx of sodium into the cell. The initial repolarization phase is due to transient opening of the potassium channels along with calcium channels. Influx of calcium causes the prolonged plateau phase of the action potential. Delayed opening of the rectifier potassium channel and delayed closure of the calcium channel leads to the repolarization phase of cardiac action potential.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 29
Incorrect
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A 25-year-old woman presented to the ED with carbon monoxide poisoning. High-flow oxygen was administered immediately. She had a GCS of 15 and her vitals were stable. Which one of the following is not an indication for hyperbaric oxygen therapy in this scenario?
Your Answer: Extrapyramidal features
Correct Answer: A carboxyhaemoglobin concentration of 16%
Explanation:Carbon monoxide (CO) poisoning, considered as the great imitator of other diseases, as the patients present with a myriad of symptoms. The carbon monoxide diffuses rapidly across the pulmonary capillary membrane binding to the haem molecule with a very high affinity (240 times that of oxygen) forming carboxy-haemoglobin (COHb). Non-smokers have a baseline COHb of ,3% while smokers have a baseline COHb of 10-15%.Use of Hyperbaric oxygen therapy (HBOT) for treatment of mild to moderate CO poisoning is not routine.The selection criteria for HBOT in cases of CO poisoning include:• COHb levels > 20-25%• COHb levels > 20% in pregnant patient • Loss of consciousness• Severe metabolic acidosis (pH <7.1)• Evidence of end-organ ischemia (e.g., ECG changes, chest pain, or altered mental status)Principle of HBOT:Exposing patients to 100 percent oxygen under supra-atmospheric conditions results in a decrease in the half-life (t1/2) of COHb, from , 90 min in atmospheric air to , 30 minutes. The amount of oxygen dissolved in the blood also rises from , 0.3 to 6 mL/dL, increasing the delivery of non-haemoglobin-bound oxygen to the tissues.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 30
Correct
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Vasodilatation of coronary arteries is caused by:
Your Answer: Hypoxia
Explanation:The heart is highly metabolically active and boasts the highest oxygen consumption by mass of any organ. This demand for oxygen is met by the coronary circulation, which is responsible for delivering blood to the myocardium and represents approximately 5% of cardiac output. Vasodilation may be due to the local effect of hypoxia on coronary vessels, or local metabolic vasodilation, or the activation of β-adrenoceptors or some combination of these mechanisms.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 31
Incorrect
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A 82-year-old woman admitted following a fractured neck of femur has been discharged. On review, she is making good progress but consideration is given to secondary prevention of further fractures. What is the most appropriate step in the prevention of further fractures?
Your Answer:
Correct Answer: Start oral bisphosphonate
Explanation:In such a clinical scenario, NICE guidelines support initiating treatment with bisphosphonates without waiting for a DEXA scan.Osteoporosis is defined as low bone mineral density caused by altered bone microstructure ultimately predisposing patients to low-impact, fragility fractures.Management:Vitamin D and calcium supplementation should be offered to all women unless the clinician is confident they have adequate calcium intake and are vitamin D repleteAlendronate is the first-line treatment. Around 25% of patients cannot tolerate alendronate, usually due to upper gastrointestinal problems. These patients should be offered risedronate or etidronate.Strontium ranelate and raloxifene are recommended if patients cannot tolerate bisphosphonates.Other medications that are useful in the treatment of osteoporosis are denosumab, teriparatide, raloxifene, etc.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 32
Incorrect
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The residual cleft of the intermediate lobe of the pituitary is lined by follicles resembling which human gland?
Your Answer:
Correct Answer: Thyroid
Explanation:The cells located between the two main pituitary lobes form what is known as the intermediate pituitary. This area secretes melanocyte-stimulating hormone and it is only a few cell layers thick. It is rich in follicles filled with colloid, and lined by basophilic cells. This configuration resembles that of another important gland: the thyroid.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 33
Incorrect
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The a-wave is created by:
Your Answer:
Correct Answer: Regurgitation of some blood to the great veins when the atria contracts in atrial systole
Explanation:The a-wave created on the venous pulse curve occurs as a result of atrial systole. Due to the pressure build-up in the atria, it causes a back pressure in the vena cava. This pressure is exerted on the valve and this back pressure is what causes a slight increase in the venous pressure.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 34
Incorrect
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Bile contains:
Your Answer:
Correct Answer: Bile acids, phosphatidylcholine, cholesterol
Explanation:The main components of bile include bile acids or bile salts, phospholipids; mainly phosphatidylcholine, cholesterol, bilirubin, inorganic salts; potassium, sodium and bicarbonate.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 35
Incorrect
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Question 36
Incorrect
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The cells that secrete pepsinogen and gastric lipase are found in which part of the stomach?
Your Answer:
Correct Answer: Body and fundus
Explanation:Stomach can be divided in to different regions. Cardia, fundus, body, antrum and pylorus from proximal end to distal end respectively. Cells that secret the inactive form of pepsin or pepsinogen are chief cells and are abundant in the body (corpus) and the fundus region of the stomach.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 37
Incorrect
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Where is the myenteric plexus (Auerbach’s plexus) located in the GIT?
Your Answer:
Correct Answer: Between the outer longitudinal and middle circular muscle layers.
Explanation:A part of the enteric nervous system, the myenteric plexus exists between the longitudinal and circular layers of muscularis externa in the gastrointestinal tract. It is found in the muscles of the oesophagus, stomach, and intestine.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 38
Incorrect
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Which of the following antiarrhythmic drugs may be used in the treatment of long QT syndrome?
Your Answer:
Correct Answer: Atenolol
Explanation:Beta-blockers are the mainstay of treatment in long QT syndrome. Implantable cardioverter-defibrillators are the most effective treatment in genotypes with a high risk of recurrence.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 39
Incorrect
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Question 40
Incorrect
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Afferent A δ fibers from nociceptors terminate primarily on neurons in which lamina:
Your Answer:
Correct Answer: I and V
Explanation:Nociceptors are receptors of pain sensation. There are 2 primary afferent/sensory pain fibers which transmit impulses from the receptor to the CNS, specifically to the dorsal horn of the spinal cord. The two fibers are A δ and C fibers. The dorsal horn of the spinal cord is the relay centre for sensory information converging from the periphery. Grey matter of the dorsal horn is subdivided in to laminae based on cytoarchitecture. C fibers terminate in lamina II the substantia gelatinosa. A δ fibers terminate primarily in lamina I but some project more deeply to terminate in lamina V.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 41
Incorrect
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Which of the following foods contain Vitamin B 12?
Your Answer:
Correct Answer: Liver, meat
Explanation:No fungi, plants, nor animals (including humans) are capable of producing vitamin B12. Only bacteria and archaea have the enzymes needed for its synthesis. Proved food sources of B12 are animal products (meat, fish, dairy products).
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This question is part of the following fields:
- Haematology
- Medicine
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Question 42
Incorrect
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Cross-bridges between actin and myosin filaments contain:
Your Answer:
Correct Answer: Calcium ions
Explanation:At rest troponin I is bound to actin and tropomyosin and covers the site where the myosin head interacts with actin. When calcium enters into the muscle, it binds with troponin C and causes a structural change in troponin I which moves out of the myosin binding site and causes the cross bridges between the actin and myosin filaments to occur.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 43
Incorrect
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Which of the following drug can cause galactorrhoea?
Your Answer:
Correct Answer: Metoclopramide
Explanation:Metoclopramide causes extrapyramidal effects (especially in children and young adults), hyperprolactinaemia, and occasionally tardive dyskinesia on prolonged administration. Also reported are drowsiness, restlessness, diarrhoea, depression, neuroleptic malignant syndrome, rashes, pruritus, oedema.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 44
Incorrect
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Which substance is produced by anterograde neurons?
Your Answer:
Correct Answer: Nitric oxide
Explanation:Nitric oxide is thought to act as an anterograde neurotransmitter. Classically in the peripheral nervous system, it diffuses from a presynaptic nerve ending to the post synaptic effecter cell which is mainly smooth muscle cells in the gastrointestinal, respiratory and urogenital tracts.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 45
Incorrect
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What is the function of the macula densa, located in the wall of the thick ascending limb?
Your Answer:
Correct Answer: Tubuloglomerular feedback.
Explanation:Macula densa cells sense changes in sodium chloride level, and will trigger an autoregulatory response to increase or decrease reabsorption of ions and water to the blood (as needed) in order to alter blood volume and return blood pressure to normal. Tubuloglomerular feedback is one of several mechanisms the kidney uses to regulate glomerular filtration rate (GFR). It involves the concept of purinergic signalling, in which an increased distal tubular sodium chloride concentration causes a basolateral release of adenosine from the macula densa cells. This initiates a cascade of events that ultimately brings GFR to an appropriate level.
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This question is part of the following fields:
- Medicine
- Renal
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Question 46
Incorrect
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Corticospinal tracts are located in the ___ of the white matter.
Your Answer:
Correct Answer: Anterior and lateral funiculi
Explanation:The corticospinal tract is a descending or a motor tract which projects nerve fibers from the cortex of the cerebrum down to different levels of the spinal cord. The descending corticospinal tract descends from the origin, through the corona radiata, posterior half of the lateral ventricle, and enters the midbrain through the cerebral peduncle. In the medulla they form the medullary pyramids on either side of midline as lateral and anterior fibers.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 47
Incorrect
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What is the function of gap junctions?
Your Answer:
Correct Answer: Diffusion of small molecules between neighbouring cells
Explanation:Gap junctions are a specialized intercellular connection between a multitude of cell-types. They directly connect the cytoplasm of two cells, which allows various molecules, ions and electrical impulses to directly pass through a regulated gate between cells.
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This question is part of the following fields:
- Cell Biology
- Medicine
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Question 48
Incorrect
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According to the Vaughan William's classification of antiarrhythmic agents, lidocaine is a:
Your Answer:
Correct Answer: Class Ib agent
Explanation:Lidocaine is an example of class IB antiarrhythmics.The Vaughan-Williams classification of antiarrhythmicsI: Membrane stabilizing agentsIA: Quinidine, Procainamide, DisopyramideIB: Lidocaine, MexiletineIC: Propafenone, Flecainide II: β blockers – Propranolol, EsmololIII: Agents widening AP – Amiodarone, Dronedarone, Dofetilide, Ibutilide, SotalolIV: Calcium channel blockers – Verapamil, DiltiazemV: Miscellaneous – Digoxin, adenosine, magnesium
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 49
Incorrect
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The conversion of haem to bilirubin is catalysed by which of these enzymes?
Your Answer:
Correct Answer: Biliverdin reductase
Explanation:Bilirubin is created by the activity of biliverdin reductase on biliverdin, a green tetrapyrrolic bile pigment that is also a product of haem catabolism.
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This question is part of the following fields:
- Hepatobiliary
- Medicine
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Question 50
Incorrect
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Which neurotransmitter is made from hydroxylation and decarboxylation of tryptophan?
Your Answer:
Correct Answer: Serotonin
Explanation:Serotonin is synthesized from the essential amino acid tryptophan. The rate-limiting step is the conversion of the amino acid to 5-hydroxytryptophan by tryptophan hydroxylase. This is then converted to serotonin by the aromatic L-amino acid decarboxylase.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 51
Incorrect
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Translation usually begins at which codon?
Your Answer:
Correct Answer: AUG
Explanation:The start codon is the first codon of a messenger RNA (mRNA) transcript translated by a ribosome. The start codon always codes for methionine in eukaryotes and the most common start codon is AUG.
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This question is part of the following fields:
- Medicine
- Metabolism
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Question 52
Incorrect
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What is the effect of oxytocin on the breast?
Your Answer:
Correct Answer: Milk ejection
Explanation:Oxytocin is a peptide hormone and neuropeptide, produced by the hypothalamus and released by the posterior pituitary. It causes the milk ejection or let-down reflex, causing the milk to be transported to the subareolar sinuses, allowing it to be released through the nipple. This response is initiated by the act of suckling by the baby, but it can be conditioned to be triggered by different stimuli.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 53
Incorrect
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A 28 year old female presents to the rheumatology clinic for review. She has a history of adult onset Still's disease and complains of joint pains and persistent skin rash despite undergoing treatment with methotrexate and etanercept. On examination, an erythematous macular rash and active synovitis is noted. CRP is high (95 mg/dl). Which of the following interventions would be most appropriate?
Your Answer:
Correct Answer: Anakinra
Explanation:Adult onset Still’s disease (AOSD) is an uncommon systemic inflammatory disease on the clinical spectrum of autoinflammatory disorders. Its presentation and clinical course may result in several well-differentiated phenotypes: from a systemic and highly symptomatic pattern to a chronic articular pattern. Overproduction of numerous pro-inflammatory cytokines is observed in AOSD. Anakinra, a human interleukin (IL)-1R antagonist, has recently been approved in the treatment of AOSD. Denosumab is a RANK ligand inhibitor used in the treatment of osteoporosis. Mepolizumab is used in the treatment of severe asthma with elevated eosinophils. There is some evidence to support the use of tocilizumab, an anti-IL6 monoclonal antibody in adult onset Still’s, but there is stronger data favouring the use of tocilizumab in the treatment of rheumatoid arthritis. Rituximab is usually reserved for patients who are unresponsive to anakinra.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 54
Incorrect
-
The end product of trehalase action on oligosaccharides is
Your Answer:
Correct Answer: Two glucose molecules
Explanation:Disaccharides are glycoside hydrolases, enzymes that break down certain types of sugars called disaccharides into simpler sugars called monosaccharides.Examples of disaccharides:Lactase (breaks down lactose into glucose and galactose)Maltase (breaks down maltose into 2 glucoses)Sucrase (breaks down sucrose into glucose and fructose)Trehalase (breaks down trehalose into 2 glucoses)
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 55
Incorrect
-
The immunoglobulin found in the highest concentration in humans is
Your Answer:
Correct Answer: IgG
Explanation:Representing approximately 75% of serum antibodies in humans, IgG is the most common type of antibody found in the circulation. IgG molecules are created and released by plasma B cells.
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This question is part of the following fields:
- Immunology
- Medicine
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Question 56
Incorrect
-
The chief cells of the stomach secrete which of the following?
Your Answer:
Correct Answer: Pepsinogens
Explanation:A gastric chief cell (or peptic cell, or gastric zymogenic cell) is a type of cell in the stomach that releases pepsinogen and gastric lipase.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 57
Incorrect
-
The main efferent input of the posterior pituitary gland comes from:
Your Answer:
Correct Answer: Paracrine hormones secreted from the hypothalamus via axons.
Explanation:The posterior pituitary or neurohypophysis consists of a collection of axonal projections emerging from the hypothalamus. It releases hormones directly from these axonal endings into circulation; these hormones are oxytocin and vasopressin.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 58
Incorrect
-
Which of the following normally has a slow depolarizing “prepotential”?
Your Answer:
Correct Answer: Sinoatrial node
Explanation:There are 2 main types of action potentials (AP) in the heart, the slow response and the fast response:The slow response is initiated by the slow calcium-sodium channels, found in the SA node (which is the natural pacemaker of the heart) and the conduction fibers of the AV node.The fast response occurs in the atrial and ventricles muscle cells and the purkinje fibers.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 59
Incorrect
-
The action of progesterone on different organs/systems includes:
Your Answer:
Correct Answer: Breasts: stimulation of lobular and alveolar development
Explanation:Progesterone is a sex hormone which affects mainly the reproductive system. In the breasts, it mediates the lobuloalveolar maturation to allow for milk production; this is done in conjunction with prolactin. It acts to maintain female reproductive and sex characteristics.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 60
Incorrect
-
Calcium needed for cardiac muscle contraction is made available during which phase of the action potential?
Your Answer:
Correct Answer: 2
Explanation:It is made available during the plateau phase of the action potential i.e. phase 2. During the plateau phase of the action potential, Calcium from the extracellular fluid enters through the L type of calcium channels. This entry triggers the release of more calcium from the sarcoplasmic reticulum via the ryanodine receptors.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 61
Incorrect
-
The complex twisting and folding of peptide chains describes which order of protein structure?
Your Answer:
Correct Answer: Secondary structure
Explanation:Secondary Structure refers to the coiling or folding of a polypeptide chain that gives the protein its 3-D shape. There are two types of secondary structures: the alpha (α) helix and the beta (β) pleated sheet.
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This question is part of the following fields:
- Medicine
- Metabolism
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Question 62
Incorrect
-
A 20-year-old male presented to the clinic with a long term history of pins and needles sensation in both hands. He also has prognathism. He also gives a history of recent onset right upper quadrant pain after being started on a new medication for his condition. Which of the following medications acting on his endocrine system can be responsible for this adverse effect?
Your Answer:
Correct Answer: Octreotide
Explanation:The patient (known case of acromegaly) seems to have developed cholelithiasis (presenting with right upper quadrant pain) probably due to octreotide.It is a long-acting analogue of somatostatin which is released from D cells of the pancreas and inhibits the release of growth hormone, glucagon, and insulin.Uses- Acute treatment of variceal haemorrhage- Acromegaly- Carcinoid syndrome- Prevent complications following pancreatic surgery- VIPomas- Refractory diarrhoeaAdverse effectsGallstones (secondary to biliary stasis)Other options:- Bromocriptine – a dopamine agonist with side effects arising from its stimulation of the brain vomiting centre.- Desmopressin – predominantly used in patients with diabetes insipidus by increasing the presence of aquaporin channels in the distal collecting duct to increase water reabsorption from the kidneys. The main side effects include headache and facial flushing due to hypertension.- Metformin – mainly reduces hepatic gluconeogenesis in patients with type 2 diabetes, common side effects include diarrhoea, vomiting, and lactic acidosis- Levothyroxine – synthetic thyroxine used in patients with hypothyroidism, common side effects result from incorrect dosing and mimic the symptoms of hyperthyroidism.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 63
Incorrect
-
Stimulation of the carotid sinus results in:
Your Answer:
Correct Answer: Drop in blood pressure
Explanation:Stimulation of the carotid sinus will result in an increase in the baroreceptor discharge. This will travel via the afferent nerves to the medulla. Signals will pass through the vagus nerve to decrease the sympathetic outflow to the heart and the blood vessels. This inhibition will result in vasodilation of the blood vessels, venodilation and bradycardia hence decreasing the total peripheral resistance and lowering the blood pressure.
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This question is part of the following fields:
- Cardiovascular
- Medicine
-
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Question 64
Incorrect
-
A 70-year-old male with advanced COPD currently on treatment with salbutamol (as required) presents for review. After a complete history and examination, you conclude that he requires to be stepped up in his inhalational therapy. The decision to add tiotropium bromide to his regime was taken. Which of the following best describe the mechanism of action of tiotropium?
Your Answer:
Correct Answer: It is a long-acting anticholinergic agent
Explanation:Tiotropium is a specific long-acting antimuscarinic agent indicated as maintenance therapy for patients with COPD (chronic obstructive pulmonary disease). It should be used cautiously in patients with narrow-angle glaucoma, prostatic hyperplasia or bladder neck obstruction.The most frequently encountered adverse effects of tiotropium include pharyngitis, bronchitis, sinusitis, dry mouth, cough, and headaches. Paradoxical bronchospasm may also occur as a rare side-effect. Dry mouth occurs in up to 14% of patients taking tiotropium, in keeping with its anticholinergic profile. Rarer side-effects include tachycardia, blurred vision, urinary retention, and constipation.
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This question is part of the following fields:
- Medicine
- Pharmacology
-
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Question 65
Incorrect
-
A 43 year old man with hemochromatosis presents with a painful and swollen right knee. X-ray shows extensive chondrocalcinosis but no fracture. Given the most likely diagnosis, which of the following would be present in the joint fluid aspirate?
Your Answer:
Correct Answer: Positively birefringent rhomboid-shaped crystals
Explanation:Pseudogout is a paroxysmal joint inflammation due to calcium pyrophosphate crystal deposition (calcium pyrophosphate dihydrate). Arthrocentesis should be performed, especially in acute cases. Polarized light microscopy: detection of rhomboid-shaped, positively birefringent CPPD crystals. Synovial fluid findings: 10,000-50,000 WBCs/μL with > 90% neutrophils. X-ray findings: cartilage calcification of the affected joint (chondrocalcinosis). Fibrocartilage (meniscus, annulus fibrosus of intervertebral disc) and hyaline cartilage (joint cartilage) may be affected.
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This question is part of the following fields:
- Connective Tissue
- Medicine
-
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Question 66
Incorrect
-
Choose the standard method for comparing distributions in data sets (such as between the expected frequency of an event and the observed frequency of an event) from the list of options.
Your Answer:
Correct Answer: Chi squared (X²) test
Explanation:The Chi-squared test evaluates if two variables are related. The other statistical tests mentioned do not perform this function.
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This question is part of the following fields:
- Medicine
- Research Skills
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Question 67
Incorrect
-
In a 70 kg male, the approximate volumes (litres) of water in the different compartments mentioned (intracellular, interstitial, vascular) are:
Your Answer:
Correct Answer: 28l, 14l, 3.5l
Explanation:In a 70kg male, approximately 60% (42 L) of the total body weight is composed of water divided proportionally in the following compartments:Intracellular fluid (ICF) – Around 67% (28 L) of total body water.Extracellular fluid (ECF) – Approximately 33% (14 L) of the total body fluid. The fluid in the intravascular compartment is about 3 L and is generally about 25% of the volume of ECF.
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This question is part of the following fields:
- Medicine
- Renal
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Question 68
Incorrect
-
A 68 year old man presents with acute symptoms of gout on his first metatarsophalangeal joint. Which option best explains the underlying mechanism of gout?
Your Answer:
Correct Answer: Decreased renal excretion of uric acid
Explanation:Primary gout is related more often to underexcretion of uric acid or overproduction.
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This question is part of the following fields:
- Connective Tissue
- Medicine
-
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Question 69
Incorrect
-
The Wiebel-Palade body found in the endothelial cells is responsible for the production and release of which factor?
Your Answer:
Correct Answer: Von Willebrand factor
Explanation:Weibel-Palade bodies are the storage granules of endothelial cells, the cells that form the inner lining of the blood vessels and heart. They store and release two principal molecules, von Willebrand factor and P-selectin, and thus play a dual role in haemostasis and inflammation.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 70
Incorrect
-
Wernicke’s area:
Your Answer:
Correct Answer: Is concerned with comprehension of auditory and visual information
Explanation:Wernicke’s area is located in the categorical hemisphere or left hemisphere in about 95% of right handed individuals and 60% of left handed individuals. It is involved in the comprehension or understanding of written and spoken language. In contrast Broca’s area is involved in production of language.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 71
Incorrect
-
Which vitamin plays a major role in the metabolism of many amino acids?
Your Answer:
Correct Answer: Vitamin B6
Explanation:Vitamin B6 is part of the vitamin B group, and its active form, pyridoxal 5′-phosphate (PLP) serves as a coenzyme in many enzyme reactions in amino acid, glucose, and lipid metabolism.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 72
Incorrect
-
A 35-year-old male was brought to you in a confused state. Although not your patient, you can make out that the man has a history of schizophrenia, and has recently had his medications altered. Clinically, you find evidence of a lower respiratory tract infection, and blood investigations indicate a neutropenic picture.What is the most likely drug causing the neutropenia?
Your Answer:
Correct Answer: Clozapine
Explanation:Clozapine can cause neutropenia or agranulocytosis.Clozapine is an atypical antipsychotic used in the treatment of schizophrenia, and in patients who are intolerant to, or unresponsive to other antipsychotics. It is a weak D2-receptor and D1-receptor blocking activity, with noradrenolytic, anticholinergic, and antihistaminic properties.Many antipsychotic drugs can occasionally cause bone marrow depression, but agranulocytosis is particularly associated with clozapine.Other side effects include:Hypotension, tachycardiaFever, sedation, seizures (with high doses)Appetite increaseConstipationHeartburnWeight gainExtrapyramidal symptomsAgranulocytosisNeuroleptic malignant syndrome
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This question is part of the following fields:
- Medicine
- Pharmacology
-
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Question 73
Incorrect
-
Which of the following does not contribute to increased stroke volume during exercise?
Your Answer:
Correct Answer: Increased length of filling time during diastole
Explanation:Prolonged aerobic exercise training may also increase stroke volume, which frequently results in a lower (resting) heart rate. Reduced heart rate prolongs ventricular diastole (filling), increasing end-diastolic volume, and ultimately allowing more blood to be ejected.
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This question is part of the following fields:
- Cardiovascular
- Medicine
-
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Question 74
Incorrect
-
Which of the following causes the closure of the ductus arteriosus during birth?
Your Answer:
Correct Answer: Reduced levels of prostaglandins
Explanation:Ductus arteriosus is kept open by the prostaglandin E2 which is a vasodilator. At birth the high levels of cyclooxygenase blocks the production of prostaglandins which results in the closure of the ductus arteriosus.
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This question is part of the following fields:
- Cardiovascular
- Medicine
-
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Question 75
Incorrect
-
Hyperkalaemia [K+ =7meq/l] can lead to the following ECG changes [Ca++ normal]
Your Answer:
Correct Answer: Peaked T waves
Explanation:Hyperkalaemia causes the formation of tall tented T waves due to altered repolarization.
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This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 76
Incorrect
-
What is the most common cause of primary hyperaldosteronism?
Your Answer:
Correct Answer: Bilateral idiopathic adrenal hyperplasia
Explanation:Primary aldosteronism, also known as primary hyperaldosteronism or Conn’s syndrome, is excess production of the hormone aldosterone by the adrenal glands resulting in low renin levels. Primary hyperaldosteronism has a number of causes. About 66% of cases are due to enlargement of both adrenal glands and 33% of cases are due to an adrenal adenoma that produces aldosterone. Other uncommon causes include adrenal cancer and an inherited disorder called familial hyperaldosteronism
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This question is part of the following fields:
- Endocrinology
- Medicine
-
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Question 77
Incorrect
-
Histamine, acetylcholine and gastrin act by way of which second messengers in the release of acid by parietal cells:
Your Answer:
Correct Answer: A and D
Explanation:Acetylcholine, Histamine and Gastrin receptors are located on the basolateral membrane of the parietal cell and control its activity. Stimulation of these receptors modulates the levels of protein kinases in the cell and brings about the changes from a resting to stimulated structure. Protein kinase catalyses conversion of ATP to cyclic AMP which activates the proton pump. Calcium ions increase gastric acid secretion elicited by gastrin released through a vagal mechanism, and also by a direct effect on parietal cells.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
-
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Question 78
Incorrect
-
Restriction Enzymes...
Your Answer:
Correct Answer: Cut DNA sequences at specific sites
Explanation:Restriction endonucleases are enzymes that recognise short sequences of double stranded DNA and cut them at specific nucleotide points or sequences. These sequences differ for different restriction endonucleases.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 79
Incorrect
-
Where is thyroglobulin produced?
Your Answer:
Correct Answer: Thyrocytes
Explanation:Thyroglobulin, or Tg, is a protein that functions as the precursor to thyroid hormones. It is synthesized by thyrocytes and then secreted into the colloid. It also functions as a negative-feedback regulator of thyroid hormone biosynthesis.
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This question is part of the following fields:
- Endocrinology
- Medicine
-
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Question 80
Incorrect
-
The net effect of active Vitamin D on calcium and phosphate homeostasis is?
Your Answer:
Correct Answer: Increase in Ca, increase in phosphate
Explanation:Bone and its metabolism are regulated by several hormones, amongst which is vitamin D. It is heavily involved in the metabolism and homeostasis of calcium and phosphate through several processes. Vitamin D works in the intestine, kidney, bone and parathyroid glands to maintain levels of calcium and phosphate, promoting its absorption, bone resorption, and proper functioning of the parathyroid to maintain adequate serum calcium levels.
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This question is part of the following fields:
- Endocrinology
- Medicine
-
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Question 81
Incorrect
-
Efferent innervation of the muscle spindle is supplied by which type of motor neuron?
Your Answer:
Correct Answer: Gama – motor neuron
Explanation:The muscle spindle is supplied by both sensory and motor nerves. Sensory supply is via Type Ia fibers whereas the motor supply is via gamma motor neurons.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 82
Incorrect
-
Carotid bodies...
Your Answer:
Correct Answer: Are located near the bifurcation of the carotid arteries bilaterally
Explanation:The carotid body is a small cluster of chemoreceptors and supporting cells located near the fork (bifurcation) of the carotid artery (which runs along both sides of the throat).The carotid body detects changes in the composition of arterial blood flowing through it, mainly the partial pressure of oxygen, but also of carbon dioxide. Furthermore, it is also sensitive to changes in pH and temperature. Carotid bodies trigger an action potential through the afferent fibers of the glossopharyngeal nerve,
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This question is part of the following fields:
- Medicine
- Respiratory
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Question 83
Incorrect
-
The liver is the principal site for?
Your Answer:
Correct Answer: Storage of iron
Explanation:The liver mainly synthesizes proteins including albumin, globulins and coalgulative factors. Vitamin B12 is taken in via the diet and stored by the liver. Vitamin C is not stored and excessive vitamin C is excreted via urine. Liver is the main site of iron storage, where it is stored in the form of ferritin.
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This question is part of the following fields:
- Hepatobiliary
- Medicine
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Question 84
Incorrect
-
Endothelial cells are attached to adjacent cells by adherent junctions via:
Your Answer:
Correct Answer: Cadherins
Explanation:Cadherins are calcium dependant molecules that mediate cell to cell adhesions in epithelial and endothelial cells among others.
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This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 85
Incorrect
-
Eosinophils provide immunity against
Your Answer:
Correct Answer: Multi cellular parasites
Explanation:Eosinophils, are a variety of white blood cells and one of the immune system components responsible for combating multicellular parasites and certain infections in vertebrates.
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This question is part of the following fields:
- Immunology
- Medicine
-
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Question 86
Incorrect
-
A 79-year-old woman has a waddling gait. History reveals enuresis and change in behaviour. What is the most likely diagnosis?
Your Answer:
Correct Answer: Normal pressure hydrocephalus
Explanation:The waddling gait and behaviour change are attributes of normal pressure hydrocephalus along with loss of bladder control which commonly happens with elder age.
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This question is part of the following fields:
- Geriatrics
- Medicine
-
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Question 87
Incorrect
-
Which of the following substances inhibits pancreatic secretion?
Your Answer:
Correct Answer: Pancreatic polypeptide
Explanation:Number of hormones and neurotransmitters can stimulate and inhibit pancreatic exocrine secretion. Cholecystokinin, secretin, vasoactive intestinal peptide and substance P stimulate pancreatic secretion. Pancreatic polypeptide, somatostatin inhibit pancreatic secretion.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
-
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Question 88
Incorrect
-
A 47-year-old woman diagnosed with oestrogen receptor positive breast cancer three months ago was started on treatment with tamoxifen. Which of the following is most likely a complaint of this patient during her review today?
Your Answer:
Correct Answer: Hot flushes
Explanation:The most likely complaint of this patient would be hot flushes.
Alopecia and cataracts are listed as possible side-effects, however they are not as prevalent as hot flushes, which are very common in pre-menopausal women.
Tamoxifen is a Selective Oestrogen Receptor Modulator (SERM) which acts as an oestrogen receptor antagonist and partial agonist. It is used in the management of oestrogen receptor-positive breast cancer
Adverse effects:
- Menstrual disturbance: vaginal bleeding, amenorrhoea
- Hot flushes – 3% of patients stop taking tamoxifen due to climacteric side-effects.
- Venous thromboembolism.
- Endometrial cancer (although antagonistic with respects to breast tissue, tamoxifen may serve as an agonist at other sites. Therefore the risk of endometrial cancer is increased). Raloxifene is a pure oestrogen receptor antagonist and carries a lower risk of endometrial cancer.
Tamoxifen is typically used for 5 years following the removal of the tumour.
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This question is part of the following fields:
- Medicine
- Pharmacology
-
-
Question 89
Incorrect
-
The celiac trunk consists of which arteries?
Your Answer:
Correct Answer: Left gastric, common hepatic, splenic
Explanation:The celiac trunk is the first major branch of the abdominal aorta. It is 1.25 cm in length. Branching from the aorta at thoracic vertebra 12 (T12). There are three main divisions of the celiac artery:- left gastric artery- common hepatic artery- splenic artery
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This question is part of the following fields:
- Cardiovascular
- Medicine
-
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Question 90
Incorrect
-
Which of the following involving the scalp may produce alopecia (hair loss)?
Your Answer:
Correct Answer: Discoid lupus erythematosus
Explanation:Causes of hair loss include:
- Dissecting cellulitis
- Fungal infections (such as tinea capitis)
- Folliculitis
- Secondary syphilis
- Demodex folliculorum
- Lupus erythematosus (hair loss may be permanent due to scarring of the hair follicles).
Psoriasis and seborrheic dermatitis commonly involve the scalp but do not produce hair loss.
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This question is part of the following fields:
- Dermatology
- Medicine
-
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Question 91
Incorrect
-
Which of the following is not innervated by the parasympathetic nerve supply?
Your Answer:
Correct Answer: Radial muscle of iris
Explanation:The sphincter pupillae is supplied by the parasympathetic fibers from the Edinger Westphal nucleus of the oculomotor nerve. The dilator pupillae (radial muscle) is supplied by the postganglionic fibers of the superior cervical sympathetic ganglion. The parasympathetic nerve supply to the salivary glands originate in the parasympathetic nucleus of the facial nerve (superior salivatory nucleus) and the glossopharyngeal nerve (inferior salivatory nucleus). The parasympathetic preganglionic fibers originate in the dorsal nucleus of the vagus nerve and descend into the thorax in the vagus nerve. The fibers terminate by synapsing with postganglionic neurons in the cardiac plexuses. Postganglionic fibers terminate on the sinoatrial and atrioventricular nodes and on the coronary arteries Parasympathetic supply to the stomach is via the vagus nerve.
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This question is part of the following fields:
- Medicine
- Neurology
-
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Question 92
Incorrect
-
The oesophagus is lined by
Your Answer:
Correct Answer: Stratified squamous epithelium
Explanation:The wall of the oesophagus from the lumen outwards consists of mucosa, submucosa (connective tissue), layers of muscle fibers between layers of fibrous tissue, and an outer layer of connective tissue. The mucosa is a stratified squamous epithelium of around three layers of squamous cells, which contrasts to the single layer of columnar cells of the stomach. The transition between these two types of epithelium is visible as a zig-zag line. Most of the muscle is smooth muscle although striated muscle predominates in its upper two thirds.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
-
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Question 93
Incorrect
-
Currents caused by opening of which of the following channels contribute to the repolarization phase of the action potential of the ventricular muscle fibers?
Your Answer:
Correct Answer: Potassium channels
Explanation:Depolarization occurs due to opening of the voltage gated sodium channels. Repolarization occurs due to opening of the voltage gates potassium channels causing an out flux of potassium ions, decreasing the membrane potential towards resting potential.
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This question is part of the following fields:
- Cardiovascular
- Medicine
-
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Question 94
Incorrect
-
A 22 year old man is being evaluated for chronic lower backache. Which of the following would most strongly point towards the diagnosis of ankylosing spondylitis?
Your Answer:
Correct Answer: Reduced lateral flexion of the lumbar spine
Explanation:Ankylosing spondylitis (spondylarthritis) is a chronic inflammatory disease of the axial skeleton that leads to partial or even complete fusion and rigidity of the spine. Males are disproportionately affected and upwards of 90% of patients are positive for the HLA-B27 genotype, which predisposes to the disease. The most characteristic early finding is pain and stiffness in the neck and lower back, caused by inflammation of the vertebral column and the sacroiliac joints. The pain typically improves with activity and is especially prominent at night. Other articular findings include tenderness to percussion and displacement of the sacroiliac joints (Mennell’s sign), as well as limited spine mobility, which can progress to restrictive pulmonary disease. The most common extra-articular manifestation is acute, unilateral anterior uveitis. Diagnosis is primarily based on symptoms and x-ray of the sacroiliac joints, with HLA-B27 testing and MRI reserved for inconclusive cases. There is no curative treatment, but regular physiotherapy can slow progression of the disease. Additionally, NSAIDs and/or tumour necrosis factor-α inhibitors may improve symptoms. In severe cases, surgery may be considered to improve quality of life. The spine adopts a bamboo shape, not lordosis. The pain usually improves as the day progresses. leg raise test causes pain in cases of meningitis etc not in this case.
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This question is part of the following fields:
- Connective Tissue
- Medicine
-
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Question 95
Incorrect
-
VIP, GIP and somatostatin play an inhibitory role in gastric acid secretion by inactivating?
Your Answer:
Correct Answer: G cells
Explanation:Gastrin is secreted from the G cells. VIP, GIP and somatostatin all inhibit acid production by inhibiting the G cells.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
-
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Question 96
Incorrect
-
A cohort study is being designed to look at the relationship between smoking and prostate cancer. What is the usual outcome measure in a cohort study?
Your Answer:
Correct Answer: Relative risk
Explanation:A cohort study is a particular form of longitudinal study that samples a cohort (a group of people who share a defining characteristic, typically those who experienced a common event in a selected period, such as birth or graduation), performing a cross-section at intervals through time. The relative risk (RR) or risk ratio is the ratio of the probability of an outcome in an exposed group to the probability of an outcome in an unexposed group. Relative risk is used in the statistical analysis of the data of experimental, cohort and cross-sectional studies, to estimate the strength of the association between treatments or risk factors, and outcomes.
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This question is part of the following fields:
- Medicine
- Research Skills
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Question 97
Incorrect
-
A 33-year-old electrical technician presents following an overdose. Anticholinergic syndrome is suspected. Which of the following is true?
Your Answer:
Correct Answer: Mydriasis occurs
Explanation:Anticholinergic syndrome occurs following overdose with drugs that have prominent anticholinergic activity including tricyclic antidepressants, antihistamines and atropine. Features include dry, warm, flushed skin, urinary retention, tachycardia, mydriasis (dilated pupils) and agitation.
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This question is part of the following fields:
- Medicine
- Pharmacology
-
-
Question 98
Incorrect
-
Question 99
Incorrect
-
Endolymph in the inner ear is rich in:
Your Answer:
Correct Answer: K
Explanation:Cochlear fluids namely endolymph and perilymph have different compositions. Perilymph is a typical extracellular fluid, with ionic composition comparable to plasma or cerebrospinal fluid. The main cation is sodium. Endolymph is a totally unique extracellular fluid, with an ion composition unlike that which is found anywhere else in the body. The major cation in the endolymph is potassium and there is virtually no sodium.
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This question is part of the following fields:
- Medicine
- Neurology
-
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Question 100
Incorrect
-
Number of cases that are infected at a specific point in time
Your Answer:
Correct Answer: Prevalence
Explanation:Prevalence in epidemiology is the proportion of a population found to have a condition (typically a disease or a risk factor such as smoking or seat-belt use). It is arrived at by comparing the number of people found to have the condition with the total number of people studied, and is usually expressed as a fraction, as a percentage or as the number of cases per 10,000 or 100,000 people. Point prevalence is the proportion of a population that has the condition at a specific point in time. Period prevalence is the proportion of a population that has the condition at some time during a given period (e.g., 12 month prevalence), and includes people who already have the condition at the start of the study period as well as those who acquire it during that period. Lifetime prevalence (LTP) is the proportion of a population that at some point in their life (up to the time of assessment) have experienced the condition
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This question is part of the following fields:
- Infectious Diseases
- Medicine
-
SESSION STATS - PERFORMANCE PER SPECIALTY
