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Question 1
Incorrect
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Question 2
Correct
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A 46 year old male, known with Rheumatoid Arthritis presents with a swollen and painful right ankle. No drug allergies are reported. On examination, the vitals are as follows: Temp: 38.8BP: 90/60 mmHgPulse: 110/min. Right ankle examination reveals tenderness, warmth, erythema and tense joint effusion. Blood samples including blood cultures are collected and fluid resuscitation is initiated. Which of the following interventions would be most appropriate for this man?
Your Answer: Administer i.v. flucloxacillin, and arrange joint aspiration urgently
Explanation:Although microscopic analysis of joint fluid aspirate and culture is the basis of septic arthritis diagnosis and should usually be collected before the administration of antibiotics, the patient is showing signs of septic shock. A delay in antibiotics might lead to worsening of symptoms so they are administered first.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 3
Correct
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The choroid plexus:
Your Answer: All are true
Explanation:The choroid plexus is a vascular structure found in all cerebral ventricles. The functional unit of the choroid plexus, composed of a capillary, enveloped by a layer of differentiated ependymal epithelium. Unlike the capillaries that form the blood-brain barrier, choroid plexus capillaries are fenestrated and have no tight junctions. The endothelium, therefore, does not form a barrier to the movement of small molecules. Instead, the blood-CSF barrier at the choroid plexus is formed by the epithelial cells and the tight junctions that link them.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 4
Correct
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Which of the following hormones cause negative feedback on the CRH/ACTH axis?
Your Answer: Cortisol
Explanation:The hypothalamic–pituitary–adrenal axis, also known as HPA axis is a set of interactions that regulate the secretion of several hormones through negative feedback. Cortisol, for example, is produced by the adrenal cortex, binds to its receptors in the hypothalamus and adenohypophysis and inhibits secretion of corticotropin releasing hormone (CRH) and adrenocorticotropic hormone (ACTH). The drop in CRH secretion leads to a decrease in ACTH secretion, which in turn causes less cortisol to be secreted.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 5
Correct
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The basic unit of contraction in myocytes is:
Your Answer: Sarcomere
Explanation:Sarcomere is the organelle where calcium is stored to be released during contraction of the muscle. It is the basic unit of contraction in striated muscle fibers. As myocytes are also striated muscles, sarcomeres also forms the basic unit of contraction. The impulses travel along the membrane and via its interaction with the dihydropyridine receptors it releases the stored calcium.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 6
Correct
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Which vitamin is found in NAD and NADP?
Your Answer: Vitamin B3
Explanation:In organisms, NAD can be synthesized from simple building-blocks (de novo) from the amino acids tryptophan or aspartic acid. In an alternative fashion, more complex components of the coenzymes are taken up from food as the vitamin called niacin (vitamin B3)
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This question is part of the following fields:
- Haematology
- Medicine
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Question 7
Incorrect
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What microscopic changes are visible in an active thyroid gland?
Your Answer: Colloid is abundant.
Correct Answer: Follicle lining cells are cuboid or columnar.
Explanation:Active follicles are lined by cuboidal or columnar cells; this is because active follicles are smaller and have less colloid. Their cells are tall because they are actively secreting hormones, whereas older follicles have a flat epithelium and are filled with more colloid.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 8
Incorrect
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The actions of thrombin result directly in the release of:
Your Answer: 6 pairs of polypeptides from each fibrinogen molecule
Correct Answer: Fibrin monomers
Explanation:Thrombin in turn acts as a serine protease that converts soluble fibrinogen into insoluble strands of fibrin, as well as catalysing many other coagulation-related reactions.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 9
Correct
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Which of the following enzymes is mainly responsible for the hydrolysis of polysaccharide 1:6a linkages?
Your Answer: Isomaltase
Explanation:Isomaltase is mainly responsible for hydrolysis of 1:6α linkages. Along with maltase and sucrase, it also breaks down maltotriose and maltose.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 10
Incorrect
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The only APCs that can activate naive T lymphocytes are:
Your Answer: Macrophages and monocytes
Correct Answer: Dendric cells
Explanation:Only professional antigen-presenting cells (macrophages, B lymphocytes, and dendritic cells) are able to activate a resting helper T-cell when the matching antigen is presented. However, macrophages and B cells can only activate memory T cells whereas dendritic cells can activate both memory and naive T cells, and are the most potent of all the antigen-presenting cells.
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This question is part of the following fields:
- Immunology
- Medicine
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Question 11
Incorrect
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Type 2 hypersensitivity is mediated by:
Your Answer: IgG only
Correct Answer: IgG, IgM & complement
Explanation:In type II hypersensitivity the antibodies, IgG and IgM bind to antigens to form complexes that activate the classical pathway of complement to eliminate cells presenting foreign antigens.
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This question is part of the following fields:
- Immunology
- Medicine
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Question 12
Correct
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A 75-year-old man has presented to the clinic with a complaint of disturbed sleep. The physician has prescribed temazepam. Which of the following best describes the mechanism of action of this drug?
Your Answer: Enhances the effect of gamma-aminobutyric acid
Explanation:Temazepam is an orally available benzodiazepine used in the therapy of insomnia. The soporific activity of the benzodiazepines is mediated by their ability to enhance gamma-aminobutyric acid (GABA) mediated inhibition of synaptic transmission through binding to the GABA-A receptor.The recommended initial dose for insomnia is 7.5 mg before bedtime, increasing as needed to a maximum dose of 30 mg. The most common side effects of temazepam are dose-related and include daytime drowsiness, lethargy, ataxia, dysarthria, and dizziness.Tolerance develops to these side effects, but tolerance may also develop to the effects on insomnia.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 13
Correct
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Colipase is secreted in an inactive form. Its activation in the intestinal lumen is by
Your Answer: Trypsin
Explanation:The enzyme trypsin exists in pancreatic juice in the inactive form trypsinogen, it is activated by the intestinal enterokinase in intestinal juice. Trypsin can then activate other protease enzymes and catalyse the reaction pro-colipase → colipase. Colipase is necessary, along with bile salts, to enable lipase function.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 14
Incorrect
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Neurons that are inactive during quiet breathing, become active when the respiratory drive for increased ventilation becomes greater than normal. These are located in the:
Your Answer: Pneumotaxic centre
Correct Answer: Ventral respiratory group
Explanation:The mechanism of control of ventilation is an interplay of multiple regions in the brain. Medullary respiratory centre sets the basic rhythm of breathing. The dorsal respiratory group integrates input from the stretch receptors and the chemoreceptors in the periphery and is composed mainly of inspiratory neurons which controls the basic rhythm of breathing. The ventral respiratory group generates breathing rhythm and integrates data coming in to the medulla. It contains both inspiratory and expiratory neurons. They are primarily active in exercise and stress.
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This question is part of the following fields:
- Medicine
- Respiratory
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Question 15
Correct
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Which of the following are true when it comes to tumour suppressor genes:
Your Answer: All of the options are true
Explanation:All of the above mentioned statements are true regarding tumour suppressor genes. Tumour suppressor genes generally follow the two-hit hypothesis, which implies that both alleles that code for a particular protein must be affected before an effect is manifested.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 16
Correct
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The Cellular Theory of Ageing involves?
Your Answer: Loss of telomeres
Explanation:Cellular theories of aging propose that human aging is the result of cellular aging, whereby an increasing proportion of cells reach senescence, a terminal stage at which cells will cease to divide. This will limit the body’s ability to regenerate and to respond to injury or stress. Telomeres are bits of DNA on the ends of chromosomes that protect chromosomes from sticking to each other or tangling, which could cause DNA to abnormally function. As cells replicate, telomeres shorten at the end of chromosomes, and this process correlates to senescence or cellular aging.
Other theories include:
- The Free Radical Theory: Implicates the gradual accumulation of oxidative cellular damage as a fundamental driver of cellular aging. This theory has evolved over time to emphasize the role of free radical induced mitochondrial DNA (mtDNA) mutations and the accumulation of mtDNA deletions. Given the proximity of mtDNA to the electron transport chain, a primary producer of free radicals, it postulates that the mutations would promote mitochondrial dysfunction and concomitantly increase free radical production in a positive feedback loop. It is known that diet, lifestyle, drugs (e.g. tobacco and alcohol) and radiation etc., are all accelerators of free radical production within the body.
- Error theory: based on the idea that errors can occur in the transcription of the synthesis of DNA. These errors are perpetuated and eventually lead to systems that do not function at the optimum level. The organism’s aging and death are attributable to these events (Sonneborn, 1979).
- The Cross-Linking Theory: also referred to as the Glycosylation Theory of Aging. In this theory it is the binding of glucose (simple sugars) to protein, (a process that occurs under the presence of oxygen) that causes various problems. Once this binding has occurred the protein becomes impaired and is unable to perform as efficiently. Living a longer life is going to lead to the increased possibility of oxygen meeting glucose and protein and known cross-linking disorders include senile cataract and the appearance of tough, leathery and yellow skin.
- The Neuroendocrine Theory First proposed by Professor Vladimir Dilman and Ward Dean MD, this theory elaborates on wear and tear by focusing on the neuroendocrine system. This system is a complicated network of biochemicals that govern the release of hormones which are altered by the walnut sized gland called the hypothalamus located in the brain. The hypothalamus controls various chain-reactions to instruct other organs and glands to release their hormones etc. The hypothalamus also responds to the body hormone levels as a guide to the overall hormonal activity. But as we grow older the hypothalamus loses it precision regulatory ability and the receptors which uptake individual hormones become less sensitive to them. Accordingly, as we age the secretion of many hormones declines and their effectiveness (compared unit to unit) is also reduced due to the receptors down-grading
- The Membrane Theory of Aging: According to this theory it is the age-related changes of the cell’s ability to transfer chemicals, heat and electrical processes that impair it. As we grow older the cell membrane becomes less lipid (less watery and more solid). This impedes its efficiency to conduct normal function and in particular there is a toxic accumulation
- The Decline Theory: The mitochondria are the power producing organelles found in every cell of every organ. Their primary job is to create Adenosine Triphosphate (ATP) and they do so in the various energy cycles that involve nutrients such as Acetyl-L-Carnitine, CoQ10 (Idebenone), NADH and some B vitamins etc. Enhancement and protection of the mitochondria is an essential part of preventing and slowing aging. Enhancement can be achieved with the above mention nutrients, as well as ATP supplements themselves.
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This question is part of the following fields:
- Cell Biology
- Medicine
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Question 17
Incorrect
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Where does control of self-reactive T cells (self-tolerance) initially occur?
Your Answer: Lymph node
Correct Answer: Thymus
Explanation:The thymus provides an inductive environment for development of T cells from hematopoietic progenitor cells. In addition, thymic stromal cells allow for the selection of a functional and self-tolerant T cell repertoire. Therefore, one of the most important roles of the thymus is the induction of central tolerance.
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This question is part of the following fields:
- Immunology
- Medicine
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Question 18
Correct
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Which of the following drugs is NOT bacteriostatic?
Your Answer: Penicillin
Explanation:Bactericidal antibiotics kill bacteria directly whereas bacteriostatic antibiotics slow their growth or reproduction. Tetracycline is a bacteriostatic antibiotic. Erythromycin which is a macrolide is mainly a bacteriostatic antibiotic but can show bactericidal action depending on the dose. Sulphonamides are mainly bacteriostatic. Penicillin inhibits cell wall synthesis therefore it is considered as bactericidal. Chloramphenicol is primarily a bacteriostatic antibiotic which inhibits protein synthesis and can exhibit bactericidal action in high concentrations.
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This question is part of the following fields:
- Infectious Diseases
- Medicine
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Question 19
Correct
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Which of the following features occurs very less frequently with drug induced lupus?
Your Answer: Glomerulonephritis
Explanation:Drug induced lupus typically presents with pulmonary involvement and no renal or neurological involvement. Hence glomerulonephritis would be highly unlikely in this case. Rash and arthralgias are classic presentations. Pleurisy can be present as pulmonary involvement may occur with DILE.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 20
Incorrect
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Which of the given adverse effects should be anticipated following the administration of an anticholinesterase?
Your Answer: Tachycardia and diarrhoea
Correct Answer: Bradycardia and miosis
Explanation:Bradycardia and miosis should be anticipated following the administration of anticholinesterases.Anticholinesterase agents include the following medications:- Pyridostigmine, neostigmine, and edrophonium which play a significant role in the diagnosis and the management of myasthenia gravis.- Rivastigmine, galantamine and donepezil are cholinesterase inhibitors found to be significantly useful in the management of Alzheimer’s disease.Mechanism of action and pharmacological effects:Inhibition of cholinesterase increases the level and the duration of action of acetylcholine within the synaptic cleft. Thus, cholinergic effects such as a reduction in heart rate (bradycardia), miosis (pupillary constriction), increased secretions, increased gastrointestinal motility and reduction in BP may occur with anticholinesterases.Toxins such as organophosphates and carbamates also are primarily anticholinergic and cause the following typical SLUDGE symptoms:- Salivation- Lacrimation- Urination- Diaphoresis- Gastrointestinal upset- Emesis
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 21
Incorrect
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Which of the following predominate in the adrenal medulla?
Your Answer: Norepinephrine secreting cells
Correct Answer: Epinephrine secreting cells
Explanation:Chromaffin cells, also known as pheochromocytes, are cells located in the adrenal medulla which specialize in the synthesis, storage, and secretion of catecholamines: 80% epinephrine and 20% norepinephrine is released into the bloodstream. For this reason, they are considered to be neuroendocrine cells.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 22
Incorrect
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A 28 year old male arrives at the clinic complaining of fever, arthralgia and urethritis. On examination, the ankle is swollen and there is a pustular rash on the dorsal foot. What is the most likely diagnosis?
Your Answer: Reactive arthritis
Correct Answer: Disseminated gonorrhoea
Explanation:DGI presents as two syndromes: 1) a bacteremic form that includes a triad of tenosynovitis, dermatitis, and polyarthralgias without purulent arthritis and 2) a septic arthritis form characterized as a purulent arthritis without associated skin lesions. Many patients will have overlapping features of both syndromes. Time from infection to clinical manifestations may range from 1 day to 3 months. There is no travel history and the rash of Lyme disease is not purulent. Reactive arthritis presents with conjunctivitis, urethritis and arthritis usually with a red hot tender and swollen joint.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 23
Incorrect
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What is the function of migrating motor complex
Your Answer: Mixing contents of the gut
Correct Answer: Clears the gut of luminal contents in preparation of the next meal
Explanation:Migrating motor complexes (MMC) are waves of electrical activity that sweep through the intestines in a regular cycle during fasting. These motor complexes trigger peristaltic waves, which facilitate transportation of indigestible substances such as bone, fiber, and foreign bodies from the stomach, through the small intestine, past the ileocecal sphincter, and into the colon. The MMC occurs every 90–120 minutes during the interdigestive phase (between meals), and is responsible for the rumbling experienced when hungry. It also serves to transport bacteria from the small intestine to the large intestine, and to inhibit the migration of colonic bacteria into the terminal ileum.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 24
Correct
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Growth hormone deficiency causes?
Your Answer: Decreased epiphyseal growth
Explanation:Growth hormone deficiency is caused by conditions affecting the pituitary gland, such as tumours. Its effects depend on the age of the patient: in infancy and childhood, growth failure is most likely to occur. The epiphyseal plate is the area in long bones where growth occurs, and it is the area affected by growth hormone deficiency. Poor growth/shortness is the main symptom of GH deficiency in children, usually resulting in growth at about half the usual rate for age.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 25
Correct
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In DNA cloning and sequencing, the bases in nucleotides chains are bound together by:
Your Answer: Hydrogen bonding.
Explanation:Nucleotides will always bind together via hydrogen bonds. There are two hydrogen bonds present between thymine and adenine and three hydrogen bonds present between guanine and cytosine.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 26
Correct
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Which of the following best describes the cardiac muscle?
Your Answer: Striated and involuntary
Explanation:Cardiac muscle (heart muscle) is an involuntary, striated muscle that is found in the walls and histological foundation of the heart, specifically the myocardium. Cardiac muscle is one of three major types of muscle, the others being skeletal and smooth muscle.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 27
Correct
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The extrinsic coagulation pathway is initiated by activation of which clotting factor?
Your Answer: Factor VII
Explanation:The tissue factor pathway (extrinsic) begins following damage to the blood vessel. FVII leaves the circulation and comes into contact with tissue factor (TF) expressed on tissue-factor-bearing cells (stromal fibroblasts and leukocytes), forming an activated complex (TF-FVIIa).
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This question is part of the following fields:
- Haematology
- Medicine
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Question 28
Incorrect
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Psoriatic arthropathy most commonly presents with which of the following types of arthritis?
Your Answer: Psoriatic spondylitis
Correct Answer: Peripheral asymmetric oligoarthropathy
Explanation:Most patients with psoriatic arthritis present with monoarthritis or asymmetric oligoarthritis. The most common form of the disease is the one involving a few joints of the peripheral skeleton with a distinct asymmetry of symptoms. Involvement of the smaller joints of the hands and feet, especially distal interphalangeal joints, seems to be a characteristic feature. Arthritis mutilans is a rare and severe complication of psoriatic arthritis.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 29
Incorrect
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Adrenergic stimulation will lead to myocyte relaxation via the following mechanisms
Your Answer: Down regulation of phospholambin
Correct Answer: Increased phosphorylation of phosholamban
Explanation:Phosphorylation of phospholamban, which increases calcium ATPase activity and sequestration of calcium in the sarcoplasmic reticulum. An increased rate of relaxation is explained because cAMP also activates the protein phospholamban, situated on the membrane of the SR, that controls the rate of uptake of calcium into the SR. The latter effect explains enhanced relaxation (lusitropic effect).
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 30
Correct
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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: 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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SESSION STATS - PERFORMANCE PER SPECIALTY
