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Question 1
Incorrect
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Calcium is transported over the brush border in the gut, via which transporter / channel?
Your Answer: Calcium / K+ exchanger
Correct Answer: TRPV 6
Explanation:Transient Receptor Potential Vanilloid 6 or TRPV 6 is a calcium channel located in the cell membrane which is present in a variety of organs, including small intestine, oesophagus, stomach, colon, placenta, kidney, and uterus. In the intestine, it is located in the apical brush-border membrane of the enterocyte, regulating the entry of calcium into the cell.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 2
Incorrect
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Where is the normal upper border of the liver situated?
Your Answer: 6th rib midclavicular line on left
Correct Answer: 6th rib midclavicular line on right
Explanation:Assessment of liver margins is important clinically to determine the size of the liver and is done via percussion during the physical examination. The liver typically extends from the fifth intercostal space or 6th rib to the right costal margin in the midclavicular line and the 10th rib on anterior axillary line.
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This question is part of the following fields:
- Hepatobiliary
- Medicine
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Question 3
Incorrect
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As assessed by immunocytochemistry and electron microscopy, the anterior pituitary gland contains how many different types of cells?
Your Answer: 7
Correct Answer: 5
Explanation:The pituitary is divided into three sections
-the anterior lobe which constitute the majority of the pituitary mass and is composed primarily of five hormone-producing cell types (thyrotropes, lactotropes, corticotropes, somatotropes and gonadotropes) each secreting thyrotropin, prolactin, ACTH, growth hormone and gonadotropins (FSH and LH) respectively.
There is also a sixth cell type in the anterior lobe -the non-endocrine, agranular, folliculostellate cells.
The intermediate lobe produces melanocyte-stimulating hormone and endorphins, whereas the posterior lobe secretes anti-diuretic hormone (vasopressin) and oxytocin.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 4
Incorrect
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What is the function of the macula densa, located in the wall of the thick ascending limb?
Your Answer: Increased solute absorption in the DCT.
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 5
Incorrect
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Which of the following skin coloration abnormalities occurs due to adrenal insufficiency due to primary adrenal disease?
Your Answer: Hypopigmentation
Correct Answer: Hyperpigmentation
Explanation:Addison’s disease, also known as primary adrenal insufficiency, or hypocortisolism is an endocrine disorder. Hyperpigmentation is one of its most common signs; it occurs as a result of an increase in pro-opiomelanocortin to produce more ACTH in response to the decreased levels of cortisol. Pro-opiomelanocortin is a precursor of melanocyte stimulating hormone (MSH), which stimulates melanocytes, causing darkening of the skin.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 6
Incorrect
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Question 7
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: v 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 8
Incorrect
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The hyperpolarization phase of pacemaker cells is dominated by ____ current.
Your Answer: H+
Correct Answer: K+
Explanation:The hyperpolarization phase is a continuation of the repolarization phase but the membrane potential dips below the resting membrane potential. This results due to the fact that the K+ channels take a longer time to close than the Na+ channels. Hence efflux of the K+ will result in hyperpolarization.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 9
Incorrect
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Which one of the following conditions is least likely to be associated with pyoderma gangrenosum?
Your Answer: Myelocytic leukaemia
Correct Answer: Syphilis
Explanation:The following are conditions commonly associated with pyoderma gangrenosum:
Inflammatory bowel disease:
- Ulcerative colitis
- Crohn’s disease
Arthritides:
- Rheumatoid arthritis
- Seronegative arthritis
Haematological disease:
- Myelocytic leukaemia
- Hairy cell leukaemia
- Myelofibrosis
- Myeloid metaplasia
- Monoclonal gammopathy
Autoinflammatory disease:
- Pyogenic sterile arthritis, pyoderma gangrenosum, and acne syndrome (PAPA syndrome)
- Granulomatosis with polyangiitis
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This question is part of the following fields:
- Dermatology
- Medicine
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Question 10
Incorrect
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What percentage of blood to the liver is supplied by hepatic artery?
Your Answer: 100%
Correct Answer: 25%
Explanation:The liver receives a dual blood supply from the hepatic portal vein and hepatic arteries. The hepatic portal vein delivers approximately 75% of the liver’s blood supply, and carries venous blood drained from the spleen, gastrointestinal tract, and its associated organs. The hepatic arteries supply arterial blood to the liver, accounting for the remaining quarter of its blood flow.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 11
Incorrect
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In the urea cycle, which substance is formed in the mitochondria?
Your Answer: Aspartate
Correct Answer: Carbamoyl phosphate
Explanation:Before the urea cycle begins ammonia is converted to carbamoyl phosphate in the mitochondria.
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This question is part of the following fields:
- Medicine
- Metabolism
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Question 12
Incorrect
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A 73-year-old female is being reviewed in the osteoporosis clinic. She had a fracture of her left hip 5 years ago and was started on alendronate. Following the development of persistent musculoskeletal pain, alendronate was replaced with risedronate, which was also stopped for similar reasons. Strontium ranelate was therefore started but was also stopped due to the development of deep vein thrombosis in the right leg. Her current T-score is -4.1. A decision is made to start a trial of denosumab. What is the mechanism of action of denosumab?
Your Answer: Pyrophosphate analogue which inhibits osteoclast activity
Correct Answer: Inhibits RANK ligand, which in turn inhibits the maturation of osteoclasts
Explanation:The principal mechanism by which strontium inhibits osteoclast activity is by enhancing the secretion of osteoprotegerin (OPG) and by reducing the expression of the receptor activator of nuclear factor κB ligand (RANKL) in osteoblasts.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 13
Incorrect
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In a 70 kg male, the approximate volumes (litres) of water in the different compartments mentioned (intracellular, interstitial, vascular) are:
Your Answer: 32l, 6l, 4l
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 14
Incorrect
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Select the correct statement regarding cholecystokinin (CCK):
Your Answer: It is inhibited by secretin.
Correct Answer: It causes gallbladder contraction and pancreatic enzyme secretion.
Explanation:CCK has a primary action of increasing the motility of the gallbladder by contracting the muscles in the mucosa of the gall bladder. Apart from this, it augments the action of secretin, resulting in the production of an alkaline pancreatic juice. It increases the synthesis of enterokinase, inhibits gastric emptying and may also enhance the motility of the small intestine and colon. It is released (secreted) by your small intestine during the digestive process. It’s sometimes called pancreozymin.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 15
Incorrect
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The reticular formation occupies which area of the brain?
Your Answer: Pre-frontal cortex
Correct Answer: Medulla and midbrain
Explanation:The reticular formation is a set of interconnected nuclei that are located along the brainstem.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 16
Incorrect
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Which one of the following is most likely to be seen in a patient with multiple endocrine neoplasia (MEN) type I?
Your Answer: Pheochromocytoma
Correct Answer: Insulinoma
Explanation:Multiple endocrine neoplasia type 1 (MEN-1 syndrome) or Wermer’s syndrome is part of a group of disorders, the multiple endocrine neoplasias, that affect the endocrine system through development of neoplastic lesions in the ‘three P’s’:Parathyroid (>90%): hyperparathyroidism due to parathyroid hyperplasiaPituitary (15-42%)Pancreas (60-70%, e.g. insulinoma, gastrinoma)
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 17
Correct
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The process in which tissue thromboplastin activates factor VII is best known as:
Your Answer: The extrinsic pathway
Explanation:In the tissue factor pathway (extrinsic), 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 18
Correct
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There will be a proportion of people in a population who have the given condition, disease or attribute at a specified point in time or over a specified period of time. Which of following is the best term which can describe the above?
Your Answer: Prevalence
Explanation:Prevalence refers to the total number of cases of a particular disease or condition present in a population at a specific point in time or over a specified period. It provides a measure of how widespread the disease or condition is within the population.
Specificity and sensitivity are terms used to describe the accuracy of diagnostic tests.
Probability refers to the likelihood of an event occurring.
Incidence is a measure of how commonly or frequently a disease occurs in a specified population over a period by providing a quick measurement of new disease diagnoses.
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This question is part of the following fields:
- Medicine
- Research Skills
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Question 19
Correct
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A 70-year-old male presents with chest pain. His past medical history includes hypertension and angina. He continues to smoke about 20 cigarettes per day despite being advised about lifestyle modifications.Blood investigations obtained in the emergency department show:Na+: 133 mmol/lK+: 3.3 mmol/lUrea: 4.5 mmol/lCreatinine: 90 μmol/lWhich among the following is the most likely explanation for the abnormalities seen in the above investigations?
Your Answer: Bendroflumethiazide therapy
Explanation:The blood investigations in this patient reveal hyponatremia as well as hypokalaemia. Among the options provided, Bendroflumethiazide therapy can cause the above presentation with the electrolyte disturbances. Note:- Spironolactone is a potassium-sparing diuretic that is associated with hyperkalaemia.- Enalapril therapy can cause side effects of dizziness, hypotension, cough, and rarely a rash.- Felodipine therapy can cause side effects of dizziness, headache, cough, and palpitations.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 20
Incorrect
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In which organ will you find extremely porous sinusoidal capillaries, with discontinuous endothelium?
Your Answer: Kidneys
Correct Answer: Liver
Explanation:The liver is the organ which contains sinusoidal capillaries with discontinuous endothelium. The brain, lungs and the intestine all contain continuous capillaries, however the kidney contains fenestrated capillaries to aid in filtration.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 21
Correct
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Which of the following cells secrete glucagon?
Your Answer: A cells
Explanation:Glucagon counteracts hypoglycaemia and opposes insulin by promoting gluconeogenesis and glycogenolysis. It also decreases fatty acid synthesis in the liver and adipose tissue, and promotes lipolysis. It is secreted by the pancreatic islet α-cells. Its production is regulated by the insulin produced in β-cells.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 22
Correct
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A 60 year old male presents with one month history of generalized headache, fever and malaise. He also complains of scalp sensitivity while combing his hair. In order to confirm the diagnosis, which of the following would be the definite test?
Your Answer: Temporal artery biopsy
Explanation:Temporal arteritis is a chronic large- and medium-sized vessel vasculitis that typically involves the temporal arteries. Classical symptoms include temporal headaches, jaw claudication, amaurosis fugax. Physical exam shows scalp tenderness, palpation of the temporal area may demonstrate an absent pulse, knot-like swelling, and vision loss. Lab results reveal an increased erythematous sedimentation rate and C-reactive protein. Temporal artery biopsy confirms the diagnosis. Management approach: high-dose systemic corticosteroids should be promptly administered even before the diagnosis is established. Temporal artery biopsy confirms the diagnosis. Inability to manage this or administer glucocorticoids might lead to development of blindness.
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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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Amongst the following cells, which is responsible for the secretion of defensins?
Your Answer: Monocytes
Correct Answer: Neutrophils
Explanation:Eosinophils are phagocytic and they are directed against helminths. Basophils are involved in allergic reactions and contain histamine and vasoactive granules in their cytoplasm. Mast cells are similar to basophils. Monocytes differentiate into macrophages in the tissue, secret interleukins and are phagocytic. Neutrophils are phagocytic but are also responsible for secreting defensins.
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This question is part of the following fields:
- Immunology
- Medicine
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Question 24
Incorrect
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Cholinergic nerves from the vagus innervate the SA and AV nodes via which receptor in the heart?
Your Answer: B1 receptor
Correct Answer: M2 receptor
Explanation:M2 receptor is found in the heart. M3 and M4 are associated with smooth muscle.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 25
Correct
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What is the function of basic electrical rhythm
Your Answer: To coordinate peristalsis and other motor activity
Explanation:The basal or basic electrical rhythm (BER) or electrical control activity (ECA) determines the frequency of the contractions in the gastrointestinal (GI) tract, thus acting to coordinate peristalsis.
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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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Role of bile salts in digestion of fats include
Your Answer: Reduce surface tension, emulsification and transportation
Explanation:Bile acts to some extent as a surfactant reducing surface tension, helping to emulsify the lipids in food. Bile salt anions are hydrophilic on one side and hydrophobic on the other side; consequently, they tend to aggregate around droplets of lipids (triglycerides and phospholipids) to form micelles, with the hydrophobic sides towards the fat and hydrophilic sides facing outwards. The hydrophilic sides are negatively charged, and this charge prevents fat droplets coated with bile from re-aggregating into larger fat particles.
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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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Which one of the following is true about bone marrow?
Your Answer: At birth the bone marrow is entirely red marrow and is converted to yellow marrow with age
Explanation:The two types of bone marrow are red marrow, which consists mainly of hematopoietic tissue, and yellow marrow, which is mainly made up of fat cells. Red blood cells, platelets, and most white blood cells arise in red marrow. Both types of bone marrow contain numerous blood vessels and capillaries. At birth, all bone marrow is red. With age, more and more of it is converted to the yellow type; only around half of adult bone marrow is red.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 28
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 29
Correct
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Which one of the following is a cause of a soft second heart sound?
Your Answer: Aortic stenosis
Explanation:Second heart sound (S2) forms the dub of lub-dub and is composed of components A2 and P2. • loud: hypertension• soft: AS• fixed split: physiological split (normally occurs during inhalation), right bundle branch block, pulmonary stenosis, and atrial septal defect.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 30
Incorrect
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Empagliflozin was found to reduce the risk of cardiovascular deaths, non-fatal myocardial infarction and non-fatal stroke when added to standard treatment plans in patients with type 2 diabetes mellitus. This information was shared in 2015 by The New England Journal of Medicine and the results were expressed per 1000 patient years. In fact, empagliflozin had an event rate of 37.3/1000 patient years and placebo an event rate of 43.9/1000 patient years. How many patients who are at high cardiovascular risk need to be treated with empagliflozin to prevent a cardiovascular death, a non-fatal myocardial infarction or a non-fatal stroke?
Your Answer: 50
Correct Answer: 150
Explanation:The number needed to treat (NNT) is an absolute effect measure that has been used to assess beneficial and harmful effects of medical interventions. In this case the NNT can be calculated as follows: NNT = 1/ Absolute risk reduction (ARR). ARR=(Control event rate expressed per 1000 patient years) – (Experimental event rate expressed per 1000 patient years) = 43.9-37.3 = 6.6/1000 patient yearsNNT=(Patient years)/ARR = 1000/ 6.6 = 151.5. The closest to 151.5 is 150, thus it is the correct answer.
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This question is part of the following fields:
- Medicine
- Research Skills
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Question 31
Correct
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Depolarization spreads rapidly through cardiac muscle fibers because of the presence of:
Your Answer: Gap junctions
Explanation:The cardiac muscles have gap junctions in between the cells. They allow for the formation of low resistance passages, which allow ions to diffuse through every muscle fiber rapidly and result in the cardiac muscles functioning as a syncytium, without any protoplasmic bridges involved.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 32
Correct
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One function of the liver is synthesis and storage of protein. Which of the following will result in hypoalbuminemia?
Your Answer: All of the above
Explanation:Both trauma and sepsis cause an acute inflammatory response causing plasma leakage of albumin. Nephropathy causes leakage of albumin from glomeruli and excretion of albumin in urine known as albuminuria. A hypercatabolic state is characterized by increased circulating catabolic hormones and increase break down of proteins.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 33
Correct
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The coronary sinus drains into the:
Your Answer: Right atrium
Explanation:The coronary sinus drains into the right atrium. Most of the venous blood returns to the heart via the coronary sinus and the anterior cardiac veins. Apart from these there are other vessels that drain directly into the heart chambers.
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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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In a 60kg adult male with normal mean arterial pressure and oxygen consumption, what proportion of the cardiac output at rest goes to the brain?
Your Answer: 15-20%
Correct Answer: 10-15%
Explanation:The rate of cerebral blood flow in the adult is typically 750 millilitres per minute, which is 10-15% of the cardiac output. On average around 13.9% of cardiac output is distributed to the brain.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 35
Incorrect
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Erythropoietin is synthesized by which cells of the nephron?
Your Answer: Principal cells in collecting ducts
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 36
Incorrect
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Which intestinal cells play a major role in secretory immunity?
Your Answer: T cells
Correct Answer: M cells
Explanation:M cells are specialized epithelial cells of the MALT or mucosa-associated lymphoid tissues. They transport antigens from the intestinal lumen to cells of the immune system, thereby initiating an immune response. T and B cells are lymphocytes found in blood. Mucous cells secrete mucous and can be considered as a part of innate immunity. Chief cells in the gastric mucosa secret pepsin.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 37
Correct
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A 28 year old man presents to the clinic with fatigue, exertional dyspnoea, abdominal discomfort, xerophthalmia and xerostomia. Examination reveals enlargement of the parotid glands bilaterally, hepatomegaly and peripheral motor neuropathy. Lab results are negative for RF, ANA, SS-A and SS-B antibodies. What is the most likely diagnosis?
Your Answer: Diffuse infiltrative lymphocytic syndrome (DILS)
Explanation:The Diffuse Infiltrative Lymphocytosis Syndrome (DILS) is a rare multisystemic syndrome described in HIV-infected patients. It is characterised by CD8(+) T-cell lymphocytosis associated with a CD8(+) T-cell infiltration of multiple organs. DILS is usually seen in uncontrolled or untreated HIV infection but can also manifest itself independently of CD4(+) T-cell counts. The syndrome may present as a Sjögren-like disease that generally associates sicca signs with bilateral parotiditis, lymphadenopathy, and extra glandular organ involvement. The latter may affect the lungs, nervous system, liver, kidneys, and digestive tract. Anomalies of the respiratory system are often identified as lymphocytic interstitial pneumonia. Facial nerve palsy, aseptic meningitis or polyneuropathy are among the more frequent neurological features. Hepatic lymphocytic infiltration, lymphocytic interstitial nephropathy and digestive tract lymphocytic infiltration account for more rarely noted complications. Sicca syndrome, organomegaly and/or organ dysfunction associated with polyclonal CD8(+) T-cell organ-infiltration are greatly suggestive of DILS in people living with HIV.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 38
Correct
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The basic taste “umami” is mediated by glutamate acting on a metabotropic receptor named:
Your Answer: mGluR4
Explanation:Umami taste or savoury taste is one of the five basic tastes described as meaty or brothy. Umami taste receptors typically respond to Glutamate. Biochemical studies have identified the taste receptors responsible for the sense of umami as modified forms of mGluR4, mGluR1 and taste receptor type 1 (T1R1), all of which have been found in all regions of the tongue bearing taste buds.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 39
Correct
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The hepatic portal vein:
Your Answer: Carries mainly nutrients from the GIT.
Explanation:The portal vein contains oxygen as any other vein in the body does. The hepatic veins are responsible for venous drainage of the liver. The main function of the portal vein is to carry absorbed nutrients in the gut for metabolism and detoxification.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 40
Correct
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In Argyll Robertson pupils…
Your Answer: All of the options given
Explanation:Argyll Robertson pupils are bilaterally small pupils that accommodate or reduce in size near an object but do not react to light. They do not constrict when exposed to bright light. They are a highly specific sign of neurosyphilis but may be seen in diabetic neuropathy as well.
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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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Presence of which of the following indicates a worse prognosis in rheumatoid arthritis?
Your Answer: Being a smoker
Correct Answer: Anti-CCP antibodies
Explanation:Rheumatoid arthritis is both common and chronic, with significant consequences for multiple organ systems. Anti-cyclic citrullinated peptide (anti-CCP) antibody testing is particularly useful in the diagnosis of rheumatoid arthritis, with high specificity, presence early in the disease process, and ability to identify patients who are likely to have severe disease and irreversible damage. However, its sensitivity is low, and a negative result does not exclude disease. Anti-CCP antibodies have not been found at a significant frequency in other diseases to date, and are more specific than rheumatoid factor for detecting rheumatoid arthritis. The other factors that are mentioned do not play a key prognostic role.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 42
Incorrect
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The choroid plexus:
Your Answer: One of its main functions is to produce CSF
Correct 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 43
Correct
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With regard to X linked disorders which of the following are true
Your Answer: X linked recessive disorders usually present in males and only very rarely present in homozygous females
Explanation:All are true for autosomal recessive disorders. Dominance rules for sex-linked gene loci are determined by their behaviour in the female: because the male has only one allele (except in the case of certain types of Y chromosome aneuploidy), that allele is always expressed regardless of whether it is dominant or recessive.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 44
Incorrect
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Ventricular depolarization plus ventricular repolarization is shown by the _____ interval
Your Answer: ST
Correct Answer: QT
Explanation:The QT interval represents ventricular depolarization as well as ventricular repolarization.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 45
Correct
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Where in the gastrointestinal tract are Brunner glands?
Your Answer: Duodenum
Explanation:Brunner’s glands (or duodenal glands) are compound tubular submucosal glands found in that portion of the duodenum which is above the hepatopancreatic sphincter (aka sphincter of Oddi). The main function of these glands is to produce a mucus-rich alkaline secretion (containing bicarbonate) in order to:- protect the duodenum from the acidic content of chyme (which is introduced into the duodenum from the stomach);- provide an alkaline condition for the intestinal enzymes to be active, thus enabling absorption to take place; lubricate the intestinal walls.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 46
Incorrect
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Which of the following portocaval anastomoses can cause problems in preterm infants?
Your Answer: Paraumbilical
Correct Answer: Patent ductus venosus.
Explanation:The ductus venosus is open at the time of the birth and closes during the first week of life in most full-term neonates; however, it may take much longer to close in pre-term neonates. After it closes, the remnant is known as ligamentum venosum. If the ductus venosus fails to occlude after birth, it remains patent (open), and the individual is said to have a patent ductus venosus and thus an intrahepatic portosystemic shunt (PSS).
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This question is part of the following fields:
- Hepatobiliary
- Medicine
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Question 47
Correct
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In Hirschsprung disease which one is incorrect
Your Answer: Due to congenital absence of myenteric and submucosal plexuses
Explanation:During normal prenatal development, cells from the neural crest migrate into the large intestine (colon) to form the networks of nerves called the myenteric plexus (Auerbach plexus) (between the smooth muscle layers of the gastrointestinal tract wall) and the submucosal plexus (Meissner plexus) (within the submucosa of the gastrointestinal tract wall). In Hirschsprung’s disease, the migration is not complete and part of the colon lacks these nerve bodies that regulate the activity of the colon. The affected segment of the colon cannot relax and pass stool through the colon, creating an obstruction.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 48
Incorrect
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Where is retinol mainly stored?
Your Answer: Eyes
Correct Answer: Liver
Explanation:Vitamin A is a group of unsaturated nutritional organic compounds that includes retinol, retinal, retinoic acid, and several provitamin A carotenoids (most notably beta-carotene). The liver stores a multitude of substances, including glucose (in the form of glycogen), vitamin A (1–2 years’ supply), vitamin D (1–4 months’ supply), vitamin B12 (3–5 years’ supply), vitamin K, iron, and copper.
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This question is part of the following fields:
- Haematology
- Medicine
-
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Question 49
Correct
-
When is the blood pressure at its lowest during pregnancy?
Your Answer: Second trimester
Explanation:It is lowest during the second trimester.
Previous studies have reported changes in blood pressure (BP) throughout pregnancy, and it was generally accepted that in clinically healthy pregnant women, BP falls gradually at first trimester, reaching the lowest around 22–24 weeks, rising again from 28 weeks, and reaching preconception levels by 36 weeks of gestation
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This question is part of the following fields:
- Cardiovascular
- Medicine
-
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Question 50
Incorrect
-
A 27-year-old male is admitted after drinking engine coolant in an apparent suicide attempt. Lab investigations reveal:
- pH 7.1 (7.36-7.44)
- pO2 15.3 kPa (11.3-12.6)
- pCO2 3.2 kPa (4.7-6.0)
- Standard bicarbonate 2.2 mmol/L (20-28)
- Serum calcium 1.82 mmol/L (2.2-2.6)
Your Answer: Haemodialysis
Correct Answer: Fomepizole infusion
Explanation:The patient’s symptoms and lab results are indicative of ethylene glycol poisoning, commonly found in engine coolant. Ethylene glycol is metabolized to toxic metabolites, including glycolic acid and oxalic acid, which can cause metabolic acidosis (evidenced by the low pH and low bicarbonate levels) and can bind calcium, leading to hypocalcemia.
Fomepizole is an antidote that inhibits alcohol dehydrogenase, the enzyme that converts ethylene glycol into its toxic metabolites. This prevents further formation of the harmful substances, allowing time for the ethylene glycol to be excreted unchanged in the urine.
While haemodialysis is also an important treatment for severe ethylene glycol poisoning, especially in cases of significant acidosis or renal failure, the immediate administration of fomepizole is the most urgent intervention to prevent further toxicity. Haemodialysis can be considered if the patient does not respond adequately to fomepizole or if there are signs of severe toxicity.
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This question is part of the following fields:
- Medicine
- Pharmacology
-
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Question 51
Incorrect
-
Where is thyroglobulin produced?
Your Answer: Colloid
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 52
Incorrect
-
A 32 year old complains of pain in her hands bilaterally. Which of the following symptoms would point towards an inflammatory joint disease such as rheumatoid arthritis?
Your Answer: Swelling of the finger joints
Correct Answer: Marked stiffness for more than an hour in the mornings
Explanation:In rheumatoid arthritis (RA), clinical symptoms of joint stiffness, pain, and functional disability are commonly most severe in the early morning. These symptoms closely follow the circadian rhythm of the pro-inflammatory cytokine, interleukin (IL)-6. In RA, the increase in nocturnal anti-inflammatory cortisol secretion is insufficient to suppress ongoing inflammation, resulting in the morning symptoms characteristic of RA. Established diagnostic criteria for RA include prolonged morning stiffness that could last up to an hour. Loss of joint mobility, pain, malaise and swelling of finger joints are features that are not specific to rheumatoid arthritis, and are found in many other conditions.
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This question is part of the following fields:
- Connective Tissue
- Medicine
-
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Question 53
Incorrect
-
Consanguinity shows a strong association with which pattern of inheritance?
Your Answer: X linked recessive
Correct Answer: Autosomal recessive
Explanation:Consanguinity involves being from the same kinship as another person. It is a common feature of an autosomal recessive mode of inheritance
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This question is part of the following fields:
- Genetics
- Medicine
-
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Question 54
Correct
-
Question 55
Incorrect
-
Which of the following provides the sympathetic nervous supply to the stomach?
Your Answer: Splanchnic plexus
Correct Answer: Coeliac plexus
Explanation:Parasympathetic innervation to the stomach is from the vagus nerve and the sympathetic innervation is from the coeliac plexus.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
-
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Question 56
Correct
-
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: 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 57
Incorrect
-
An important enzyme in renal tissue responsible for the conversion of glutamine to glutamate and the subsequent production of NH4 is called?
Your Answer: Glutamic dehydrogenase
Correct Answer: Glutaminase
Explanation:Glutaminase catalyses the following reaction:Glutamine + H2O → Glutamate + NH3
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This question is part of the following fields:
- Medicine
- Renal
-
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Question 58
Correct
-
Where are the cell bodies of preganglionic neurons located?
Your Answer: Lateral column
Explanation:The cell bodies of the preganglionic neurons are located in the lateral grey column of the spinal cord and in the motor nuclei of the 3rd, 7th, 9th and 10th cranial nerves.
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This question is part of the following fields:
- Medicine
- Neurology
-
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Question 59
Correct
-
A cohort study is developed to assess the correlation between blood pressure and working long hours. After 10 years of follow-up and for the 1050 individuals working less than 40 hours per week, 1000 patients had normal blood pressure and 50 patients were diagnosed with hypertension. For the 660 patients working more than 40 hours per week, 600 patients had normal blood pressure and 60 patients were diagnosed with hypertension. If you work more than 40 hours per week, what is the odds ratio of developing hypertension compared to the individuals working less than 40 hours per week?
Your Answer: 2
Explanation:An odds ratio (OR) is a measure of the association between an exposure and an outcome. The OR represents the odds that an outcome will occur given a particular exposure, compared to the odds of the outcome occurring in the absence of that exposure. Odds ratios are most commonly used in case-control studies, however they can also be used in cross-sectional and cohort study designs as well (with some modifications and/or assumptions). Wherea = Number of exposed casesb = Number of exposed non-casesc = Number of unexposed casesd = Number of unexposed non-casesOR=(a/c) / (b/d) = ad/bc
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This question is part of the following fields:
- Medicine
- Research Skills
-
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Question 60
Correct
-
Question 61
Correct
-
Mutation in RB can lead to the formation of which cancer?
Your Answer: Retinoblastoma
Explanation:Patients with a history of autosomal dominant familial retinoblastoma have at least one mutated copy of the RB gene. This predisposes the patient to develop retinoblastoma in one or both the eyes. Patients with a family history should be screened properly so that it can be detected and treated as early as possible.
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This question is part of the following fields:
- Genetics
- Medicine
-
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Question 62
Correct
-
Which one of the following statements regarding epidemiological measures is correct?
Your Answer: Cross-sectional surveys can be used to estimate the prevalence of a condition in the population
Explanation:The incidence rate is the number of new cases per population at risk in a given time period. For example, if a population initially contains 1,000 non-diseased persons and 28 develop a condition over two years of observation, the incidence proportion is 28 cases per 1,000 persons per two years, i.e. 2.8% per two years.Prevalence is the proportion of a particular population found to be affected by a medical condition (typically a disease or a risk factor such as smoking or seat-belt use). It is derived 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.Incidence should not be confused with prevalence, which is the proportion of cases in the population at a given time rather than rate of occurrence of new cases. Thus, incidence conveys information about the risk of contracting the disease, whereas prevalence indicates how widespread the disease is.
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This question is part of the following fields:
- Medicine
- Research Skills
-
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Question 63
Incorrect
-
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: Arrange DEXA scan + start strontium ranelate if T-score < -2.5 SD
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 64
Correct
-
Question 65
Correct
-
Which of the following associations is false?
Your Answer: Mandibular nerve – foramen lacerum
Explanation:– The olfactory nerves pass through the cribriform plate- The maxillary division of the trigeminal nerve passes through the foramen rotundum- The facial nerve passes through the stylomastoid foramen- The mandibular division of the trigeminal nerve pass through the foramen ovale- The glossopharyngeal nerve passes through the jugular foramen.
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This question is part of the following fields:
- Medicine
- Neurology
-
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Question 66
Correct
-
The ependyma fuse with which of the following to from the choroid plexus?
Your Answer: Tela choroidea
Explanation:The choroid plexus produces the cerebrospinal fluid (CSF) in the ventricles of the brain. It consists of modified ependymal cells. Tela choroidea is a region of pia mater of the meninges and underlying ependyma that’s a part of the choroid plexus. It is a very thin layer of the connective tissue of pia mater that overlies and covers the ependyma.
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This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 67
Incorrect
-
Which clotting factor is responsible for stabilization of the fibrin clot by formation of covalent cross-linkages?
Your Answer: Factor VIII
Correct Answer: Factor XIIIa
Explanation:Factor XIII or fibrin stabilizing factor is an enzyme of the blood coagulation system that crosslinks fibrin. Deficiency of this factor (FXIIID) affects clot stability.
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This question is part of the following fields:
- Haematology
- Medicine
-
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Question 68
Correct
-
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 69
Incorrect
-
Which of the following cells will degranulate and release histamine when binding to IgE?
Your Answer: Eosinophils
Correct Answer: Basophils
Explanation:Basophils have protein receptors on their cell surface that bind IgE, an immunoglobulin involved in microparasite defence and allergy. When activated, basophils degranulate to release histamine, proteoglycans (e.g. heparin and chondroitin), and proteolytic enzymes (e.g. elastase and lysophospholipase).
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This question is part of the following fields:
- Haematology
- Medicine
-
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Question 70
Incorrect
-
The lamina propria contains all of the following except:
Your Answer: Plasma cells
Correct Answer: Neutrophils
Explanation:The connective tissue of the lamina propria is very loose, allowing it to be very cell rich. The cell population of the lamina propria is variable and can include, for example, fibroblasts, lymphocytes, plasma cells, macrophages, eosinophilic leukocytes, and mast cells. It provides support and nutrition to the epithelium, as well as the means to bind to the underlying tissue.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
-
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Question 71
Correct
-
The intestine is lined by:
Your Answer: Simple columnar epithelium
Explanation:In the small intestine, epithelium is simple columnar and specialised for absorption. The epithelium is arranged into villi, creating a brush border and increasing the area for absorption. The epithelium is simple columnar with microvilli.In the colon, epithelium is simple columnar and without villi. Goblet cells, which secrete mucous, are also present.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
-
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Question 72
Correct
-
The primary auditory cortex is:
Your Answer: Brodmann area 41
Explanation:A Brodmann area in the brain is defined by cytoarchitecture, histology and organization of cells:Primary Sensory 3,1,2Primary Motor 4Premotor 6Primary Visual 17Primary Auditory 41Brocas 44
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This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 73
Incorrect
-
Which one of the following statements regarding the normal distribution is correct?
Your Answer: Is also referred to as the binomial distribution
Correct Answer: Mean = mode = median
Explanation:Normal distribution, also known as the Gaussian distribution, is a probability distribution that is symmetric about the mean. The normal distribution has the following properties:- It is symmetric around the mode, the median and the mean of the distribution.- It is unimodal- The area under the curve and over the x-axis is unity (i.e. equal to one).- Its density has two inflection points.- Its density is log-concave.The standard deviation (SD) is a measure of how much dispersion exists from the mean. SD = square root (variance)
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This question is part of the following fields:
- Medicine
- Research Skills
-
-
Question 74
Incorrect
-
Select a factor which stimulates glucagon secretion.
Your Answer: Somatostatin
Correct Answer: Protein meal
Explanation:Several studies have shown that glucagon levels are increased in individuals with a high protein diet. It is still debated, however, whether this type of diet affects insulin levels as well.
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This question is part of the following fields:
- Endocrinology
- Medicine
-
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Question 75
Correct
-
Which one of the following nerve fibers has the fastest conduction velocity?
Your Answer: α fiber
Explanation:α nerve fibers are characterized by being highly myelinated, which confers them with fast conduction properties. They innervate extrafusal skeletal muscle fibers, and their conduction velocity is between 80-120 m/s.
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This question is part of the following fields:
- Medicine
- Neurology
-
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Question 76
Incorrect
-
The nucleus tractus solitaries is medullary nucleus that processes the following inputs except:
Your Answer: Taste from the anterior 2/3 of the tongue (CN VII)
Correct Answer: Sensory input from the semi-circular canal (CN VIII)
Explanation:Located in the brain stem is a series of purely sensory nuclei known as tractus solitaries. Inputs of the nucleus tractus solitaries include:Taste information from the facial nerve (anterior 2/3 of the tongue), glossopharyngeal nerve (posterior 1/3) and vagus nerve (small area on the epiglottis).Sensory information from the ear (auricular branch of the vagus nerve).Chemoreceptors and mechanoreceptors of the general visceral afferent pathway (GVA) in the carotid body via glossopharyngeal nerve, aortic bodies, and the sinoatrial node, via the vagus nerve.Chemically and mechanically sensitive neurons of the general visceral afferent pathway (GVA) with endings located in the heart, lungs, airways, gastrointestinal system, pharynx, and liver via the glossopharyngeal and vagus nerves.
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This question is part of the following fields:
- Medicine
- Neurology
-
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Question 77
Correct
-
With regard to X-linked disorders which of the following are true:
Your Answer: X linked recessive disorders usually present in males and only very rarely present in homozygous females
Explanation:X linked disorders are more common in males as they only need one mutated copy of the X chromosome to manifest the disease with full severity while the females need two X chromosomes to manifest the disease, even with one defected X chromosome the severity is less than that seen in males.
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This question is part of the following fields:
- Genetics
- Medicine
-
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Question 78
Correct
-
Question 79
Correct
-
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 80
Incorrect
-
Troponin I is inhibited by calcium binding to:
Your Answer: Tropomyosin
Correct Answer: Troponin c
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 cause 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 81
Correct
-
Regarding cardiac contractility, catecholamines exert their inotropic effect via:
Your Answer: Β1-adrenergic receptors and gs
Explanation:Catecholamines exert their inotropic effect on the heart via the B1 adrenergic receptors and Gs, stimulating adenyl cyclase and increasing the production of cAMP.
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This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 82
Incorrect
-
Regarding the formation of CSF, which of the following is true?
Your Answer: The rate of formation always depends on intraventricular pressure
Correct Answer: Its composition resembles that of brain ECF
Explanation:In normal adults CSF volume is around 125ml to 150ml. Turnover of entire volume of cerebrospinal fluid a day is about 3 to 4 times a day. Composition of CSF is similar to that of plasma except that CSF is nearly protein-free compared with plasma and has a different electrolyte level. About 80% of CSF is produced by the choroid plexus. It is also produced by a single layer of column shaped ependymal cells. The composition and rate of CSF generation depends on several factors and is influenced by hormones and the content and pressure of blood and CSF.
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This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 83
Correct
-
Which of the following vitamin deficiencies is associated with xerophthalmia?
Your Answer: Vitamin A
Explanation:Xerophthalmia caused by a severe vitamin A deficiency is described by pathologic dryness of the conjunctiva and cornea. The conjunctiva becomes dry, thick and wrinkled. If untreated, it can lead to corneal ulceration and ultimately to blindness as a result of corneal damage.
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This question is part of the following fields:
- Haematology
- Medicine
-
-
Question 84
Incorrect
-
In the presence of oxygen , lactate that was produced under anaerobic conditions is converted to:
Your Answer: Acetyl- CoA
Correct Answer: Pyruvate
Explanation:Lactate can be used in two ways:Oxidation back to pyruvate by well-oxygenated muscle cells, heart cells, and brain cells. Pyruvate is then directly used to fuel the Krebs cycle orConversion to glucose via gluconeogenesis in the liver and release back into circulation.
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This question is part of the following fields:
- Cell Biology
- Medicine
-
-
Question 85
Incorrect
-
Question 86
Incorrect
-
Bone marrow barrier is important to:
Your Answer: All of the above
Correct Answer: Allow mature red blood cells to pass into circulation
Explanation:The blood vessels of the bone marrow constitute a barrier, inhibiting immature blood cells from leaving the marrow. Only mature blood cells contain the membrane proteins, such as aquaporin and glycophorin, that are required to attach to and pass the blood vessel endothelium.
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This question is part of the following fields:
- Haematology
- Medicine
-
-
Question 87
Incorrect
-
The main efferent input of the posterior pituitary gland comes from:
Your Answer: Paracrine hormones secreted from the hypothalamus via pituitary portal veins
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
-
-
Question 88
Correct
-
Free radicals are best defined by which of the following statements.
Your Answer: Atoms or molecules with unpaired electrons
Explanation:Free radicals form when one of weak bond between electrons is broken and an uneven number of electrons remain. This means the electron is unpaired, making it chemically reactive and attempt to steal an electron from a neighbouring molecule to stabilize itself.
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This question is part of the following fields:
- Cell Biology
- Medicine
-
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Question 89
Incorrect
-
Question 90
Correct
-
A 35 year old female, known case of anti phospholipid syndrome, arrives at the clinic due to a swollen and painful left leg. Doppler ultrasonography confirms the diagnosis of a deep vein thrombosis. She was previously diagnosed with DVT 4 months back and was on warfarin therapy (target INR 2-3) when it occurred. How should her anticoagulation be managed?
Your Answer: Life-long warfarin, increase target INR to 3 - 4
Explanation:If the INR in the range of 2-3 has still resulted in thrombosis, the target INR is increased to 3-4. However, because the risk of bleeding increases as the INR rises, the INR is closely monitored and adjustments are made as needed to maintain the INR within the target range.
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This question is part of the following fields:
- Connective Tissue
- Medicine
-
-
Question 91
Correct
-
What is the function of secondary messengers?
Your Answer: Communication from extracellular to intracellular signalling pathways
Explanation:First messengers may not physically cross the phospholipid bilayer to initiate changes within the cell directly. This functional limitation necessitates the cell to devise signal transduction mechanisms to transduce first messenger into second messengers, so that the extracellular signal may be propagated intracellularly. Second messengers are intracellular signalling molecules released by the cell to trigger physiological changes such as proliferation, differentiation, migration, survival, and apoptosis. Secondary messengers are therefore one of the initiating components of intracellular signal transduction cascades.
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This question is part of the following fields:
- Cell Biology
- Medicine
-
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Question 92
Correct
-
The ability of the SA node cells to allow ionic flow through channels activated in a hyperpolarized state is known as:
Your Answer: Pace maker potential
Explanation:Rhythmically discharging cells have a membrane potential that, after each impulse, declines to the firing level. Thus this prepotential or Pacemaker potential triggers the next impulse. The inherent leakiness of the sinus nodal fibers to Na+ and Ca2+ causes their self excitation.
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This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 93
Incorrect
-
Which neuron secretes glutamate as its neurotransmitter?
Your Answer: Stellate
Correct Answer: A delta and C pain fibers
Explanation:A delta and C fibers use glutamate as their primary neurotransmitter where it acts as a fast acting localized neurotransmitter.
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This question is part of the following fields:
- Medicine
- Neurology
-
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Question 94
Correct
-
The transport of the di- and tri-peptides into enterocytes is by:
Your Answer: H+ dependent peptide transporter 1
Explanation:Peptides longer that four amino acids are not absorbed. There is abundant absorption of di and tri peptidases in the small intestine. They are absorbed into the epithelial cell of the small intestine via a transporter called Peptide Transporter 1 by co transport with H+ ions.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 95
Correct
-
One of the cells of the bone marrow that are responsible for forming the various forms of differentiated blood cells are called?
Your Answer: Hematopoietic stem cell
Explanation:Hematopoietic stem cells (HSCs) or hemocytoblasts are the stem cells that give rise to all the other blood cells through the process of haematopoiesis. They are derived from mesoderm and located in the red bone marrow, which is contained in the core of most bones.
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This question is part of the following fields:
- Haematology
- Medicine
-
-
Question 96
Incorrect
-
Which of the following proteins are NOT synthesized in the liver?
Your Answer: Y-globulin
Correct Answer: Steroid
Explanation:Human steroidogenesis occurs in a number of locations:- Corticosteroids are produced in the adrenal cortex.- Oestrogen and progesterone are made primarily in the ovary and the placenta during pregnancy, and testosterone in the testes.- Testosterone is also converted to oestrogen to regulate the supply of each in females and males.- Some neurons and glia in the central nervous system (CNS) express the enzymes required for the local synthesis of pregnant neurosteroids, de novo or from peripheral sources.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 97
Incorrect
-
After eating a meal containing a moderate amount of fat, which percentage of fat is likely to be absorbed from the GIT in an adult?
Your Answer: 75%
Correct Answer: 95%
Explanation:About 95% of dietary fat is absorbed.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 98
Incorrect
-
What is the most abundant cell type in the central nervous system called?
Your Answer: Neuron
Correct Answer: Astrocyte
Explanation:Astrocytes are the supporting cells of the central nervous system. There are two types; the fibrous type is found in the white matter and the protoplasmic type in the grey matter. They are the most abundant cell type in the CNS.
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This question is part of the following fields:
- Medicine
- Neurology
-
-
Question 99
Incorrect
-
Question 100
Correct
-
Somatostatin is responsible for?
Your Answer: Decreased gastrin release
Explanation:Somatostatin is an inhibitory hormone secreted from the D cells of the Pancreatic Islets. It causes the inhibition of gastrin (decreasing stomach acid production), CCK (decreasing gallbladder motility), gastrin inhibitory peptide and secretin. Gastrin production is also inhibited by secretin, GIP, VIP, glucagon and calcitonin.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
-
-
Question 101
Correct
-
In the functional unit of the liver (acinus), the oxygenation…
Your Answer: Reduces towards the centre
Explanation:Cells located close to the portal triad or peripheral zone which consist of arterioles from the hepatic artery are the most oxygenated cells. Cells in the central zone are least oxygenated and mainly receive blood supply from the central vein which is a branch of the hepatic vein.
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This question is part of the following fields:
- Hepatobiliary
- Medicine
-
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Question 102
Correct
-
Regarding blood supply to the heart;
Your Answer: Coronary arteries fill as the heart relaxes
Explanation:The heart muscles acts like the skeletal muscle in the fact that it also compress the vessels during contraction. As the pressure in the ventricle is slightly greater than in the aorta the coronary vessels collapse during systole. Blood flows through them during the diastole phase of contraction.
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This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 103
Correct
-
What is the name of the area that indicates the site of active B lymphocyte proliferation?
Your 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 104
Incorrect
-
Activation of nitric oxide synthesis by endothelial cells is triggered by:
Your Answer: Bradykinin
Correct Answer: All of the above
Explanation:Acetylcholine, histamine, bradykinin, vasoactive intestinal peptide (VIP) and shear stress on the endothelial cells causing the release of NO. NO is formed from arginine and causes vasodilatation of the blood vessels.
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This question is part of the following fields:
- Cardiovascular
- Medicine
-
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Question 105
Correct
-
Coronary flow is reduced during
Your Answer: Tachycardia
Explanation:Maximum amount of blood flow in the coronary arteries occur during diastole. When the heart rate increases which is also called tachycardia the duration of diastole decreases. Hence the amount of blood flow to the cardiac muscle also decreases.
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This question is part of the following fields:
- Cardiovascular
- Medicine
-
-
Question 106
Correct
-
Which of the following stimuli increase growth hormone secretion?
Your Answer: Ghrelin
Explanation:Ghrelin is a hormone which serves as an endogenous ligand for the growth hormone secretagogue receptor. It acts on the pituitary and the hypothalamus by affecting the vagus nerve. It acts on the somatotrophs of the anterior pituitary, GHRH-secreting neurons, and on GHIH-secreting neurons in the hypothalamus, causing a time-dependent and pulsatile stimulation over the secretion of growth hormone.
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This question is part of the following fields:
- Endocrinology
- Medicine
-
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Question 107
Incorrect
-
The mitochondrial chromosome is a circular DNA molecule. They encode for proteins needed for ATP production. These proteins are also essential for:
Your Answer: Krebs cycle
Correct Answer: Apoptotic cell death
Explanation:The intrinsic pathway or the mitochondrial pathway of apoptosis is activated due to the loss of BCL-2 and other antiapoptotic proteins. This loss results in the increased membrane permeability and release of cytochrome C which activates caspases downstream resulting in apoptosis.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 108
Incorrect
-
A 18-year-old girl is brought to A&E having ingested at least 16 tablets of paracetamol 8 hours earlier. What should her immediate management consist of?
Your Answer: Plasma paracetamol concentration estimation
Correct Answer: Intravenous N-acetylcysteine
Explanation:Activated charcoal is useful if given within one hour of the paracetamol overdose. Liver function tests, INR and prothrombin time will be normal, as liver damage may not manifest until 24 hours or more after ingestion.The antidote of choice is intravenous N-acetylcysteine, which provides complete protection against toxicity if given within 10 hours of the overdose.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 109
Incorrect
-
What is the function of cytotoxic T cells?
Your Answer: Attack and destroy cells that have the antigen which deactivated them
Correct Answer: Kill by inserting perforins and by initiating apoptosis
Explanation:Cytotoxic T cells, once activated, approach the infected cell, insert perforins and release granzymes inducing apoptosis.
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This question is part of the following fields:
- Immunology
- Medicine
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Question 110
Incorrect
-
A 45 year old man presents with fever, malaise, weight loss and myalgias that have been occurring for a month. You suspect polyarteritis nodosa and arrange for some lab investigations. Which of the following abnormality would most likely be present?
Your Answer: Positive ANCA
Correct Answer: Elevated creatinine
Explanation:People with polyarteritis nodosa often exhibit anaemia of chronic disease. Leucocytosis and eosinophilia may also be present. ANCA is only rarely positive. As polyarteritis nodosa affects the kidneys as well, the creatinine is elevated in most cases.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 111
Correct
-
Where does most fat digestion begin?
Your Answer: Duodenum
Explanation:Digestion of some fats can begin in the mouth where lingual lipase breaks down some short chain lipids into diglycerides. However fats are mainly digested in the small intestine (in the duodenum). The presence of fat in the small intestine produces hormones that stimulate the release of pancreatic lipase from the pancreas and bile from the liver which helps in the emulsification of fats for absorption of fatty acids.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 112
Incorrect
-
A 56-year-old male presents to the emergency department with confusion and agitation for the past four hours. He is a known alcoholic who has abstained from drinking for the past three days.On examination, he is sweating, agitated and disorientated. His temperature is 37.7°C, pulse 112 bpm regular and blood pressure is 150/76 mmHg. Blood investigations performed in the emergency department reveal:FBC: NormalU&E: NormalPlasma glucose: 4.6 mmol/l (3.6-6)Which of the following medications would be the most appropriate treatment for this man?
Your Answer: Oral diazepam
Correct Answer: Oral lorazepam
Explanation:The most probable diagnosis for this patient is delirium tremens due to alcohol withdrawal, which should be treated as a medical emergency. Delirium tremens is a hyperadrenergic state and is often associated with tachycardia, hyperthermia, hypertension, tachypnoea, tremor, and mydriasis.Treatment:- The most common and validated treatment for alcohol withdrawal is benzodiazepine: first-line treatment includes oral lorazepam. – If the symptoms persist, or the medication is refused, parenteral lorazepam, haloperidol or olanzapine should be given.- Central-acting, alpha-2 agonists such as clonidine and dexmedetomidine should not be used alone for the treatment of alcohol withdrawal.- It is also recommended to avoid using alcohol, antipsychotics, anticonvulsants, beta-adrenergic receptor blockers, and baclofen for the treatment of alcohol withdrawal as there are not enough studies to support the safety of these.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 113
Correct
-
The coronary arteries fill during?
Your Answer: Diastole
Explanation:During systole the coronary arteries collapse as a result of the pressure due to contraction that is exerted on them. During diastole the heart muscle relaxes and the pressure on the coronary vessels is relieved allowing blood to flow through them to the subendocardium.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 114
Correct
-
Near the transcription site of a gene, the site at which RNA polymerase and its cofactors bind is known as the:
Your Answer: Promotor
Explanation:Transcription will begin when the RNA polymerase II binds to the promotor. The promotor is a sequence of 25 nucleotides found upstream from the start site of transcription. This promotor sequence is known as the TATA box. Transcription factors also bond along with RNA polymerase to this site to form a complex. However some may bind to regulatory elements proximal to the promotor site.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 115
Incorrect
-
Which of the following drugs would be the safest to prescribe in a 22 year old man with seropositive rheumatoid arthritis who is planning to start a family?
Your Answer: Methotrexate
Correct Answer: Prednisolone
Explanation:Prednisolone although has many undesirable side effects it may be considered relatively safe compared to the drugs that are provided here. Prolonged treatment with sulphasalazine may depress semen quality and cause irreversible infertility. Methotrexate and leflunomide both inhibit purine/pyrimidine synthesis (the former by inhibiting folate metabolism) and are contraindicated in pregnancy or while trying to conceive. In males, a temporary or permanent decrease in sperm count may occur with cyclophosphamide. Because the recovery of fertility after cyclophosphamide therapy is variable, sperm banking should be considered before treatment is begun.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 116
Incorrect
-
Which among the following antihypertensives is centrally acting?
Your Answer: Hydralazine
Correct Answer: Moxonidine
Explanation:Moxonidine and alpha-methyl dopa are centrally acting antihypertensives and modify blood pressure through modifying sympathetic activity.Other options:Verapamil is a calcium antagonist.Minoxidil and hydralazine are both vasodilators.Phenoxybenzamine is an alpha-blocker.Adverse effects:Dry mouth and somnolence were the most frequently reported adverse events, followed by headache, dizziness, nausea and allergic skin reactions.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 117
Correct
-
In most somatic cells telomeres progressively shorten as:
Your Answer: The cell divides
Explanation:Telomere length shortens with age. Progressive shortening of telomeres leads to senescence, apoptosis, or oncogenic transformation of somatic cells, affecting the health and lifespan of an individual. Telomeres prevent the chromosomes from shortening and prevent the coding portion of the DNA from being lost, thus allowing the cell to replicate indefinitely. During replication telomeres may be lost resulting in cell death.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 118
Correct
-
What does a deficiency of adenosine deaminase lead to?
Your 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 119
Incorrect
-
Which statement is incorrect regarding nociceptor C fibers…
Your Answer: Activity in the fiber activates a slow pain response
Correct Answer: They are thinly myelinated
Explanation:Group C nerve fibers are unmyelinated and have a small diameter, which means they conduct impulses at a low velocity. They carry sensory information and nociception.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 120
Correct
-
Question 121
Correct
-
The right border of the heart corresponds to which line on the surface of the chest?
Your Answer: Line drawn from the 3rd right costal cartilage to the 6th right costal cartilage
Explanation:The right border corresponds to a line drawn from the 3rd right costal cartilage to the 6th right costal cartilage; this border is slightly convex to the right.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 122
Correct
-
The HIV virus:
Your Answer: P24 is a core protein
Explanation:HIV is different in structure from other retroviruses. It is roughly spherical with a diameter of about 120 nm, around 60 times smaller than a red blood cell. It is composed of two copies of positive single-stranded RNA that codes for the virus’s nine genes enclosed by a conical capsid composed of 2,000 copies of the viral protein p24. The single-stranded RNA is tightly bound to nucleocapsid proteins, p7, and enzymes needed for the development of the virion such as reverse transcriptase, proteases, ribonuclease and integrase. A matrix composed of the viral protein p17 surrounds the capsid ensuring the integrity of the virion particle. Reverse transcriptase copies the viral single stranded RNA genome into a double-stranded viral DNA.
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This question is part of the following fields:
- Infectious Diseases
- Medicine
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Question 123
Correct
-
Pancreatic juice is usually?
Your Answer: Alkaline
Explanation:Pancreatic juice is alkaline in nature and has a high amount of bicarbonate ions. About 1500 ml is secreted every day. It also contains a large quantity of enzymes in the inactive form.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 124
Correct
-
Compact/cortical bone makes up
Your Answer: The outer layer of most bones and accounts for 80% of bone in the body
Explanation:Cortical, lamellar, or compact bone, is more dense than spongy bone and it forms the rigid, outer layer of bones, also called cortex. It consists of packed osteons, with a central osteonic canal surrounded by concentric rings. Spaces called lacunae are filled with osteocytes, and channels called canaliculi go from the lacunae to the osteonic canal. The strength of cortical bone allows it to support the body and protect organs. It also stores different elements, such as calcium.
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This question is part of the following fields:
- Endocrinology
- Medicine
-
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Question 125
Correct
-
What is the structure of nucleosomes?
Your Answer: Strands of double strand DNA + histones
Explanation:DNA is packed and condensed by binding to histone proteins. The double stranded DNA forms a complex with histone proteins which is called a nucleosome. There are 8 histone proteins contained in one core of nucleosome.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 126
Incorrect
-
Which one of the following neurotransmitters is considered a monoamine?
Your Answer: Glutamate
Correct Answer: Dopamine
Explanation:Monoamines are a class of neurotransmitters that include:
- Dopamine: A neurotransmitter involved in reward, motivation, and motor control.
- Norepinephrine: A neurotransmitter involved in arousal, attention, and stress responses.
- Serotonin: Although not listed in the options, it is another key monoamine involved in mood regulation.
The other neurotransmitters listed are not monoamines:
- Acetylcholine: This is a different type of neurotransmitter involved in muscle activation and various brain functions.
- GABA (gamma-aminobutyric acid): This is the main inhibitory neurotransmitter in the central nervous system.
- Glutamate: This is the main excitatory neurotransmitter in the central nervous system.
- Glycine: An inhibitory neurotransmitter in the central nervous system.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 127
Correct
-
What is the primary problem of achalasia
Your Answer: Deficiency of myenteric plexus at the lower oesophageal sphincter
Explanation:Oesophageal achalasia is an oesophageal motility disorder involving the smooth muscle layer of the oesophagus is characterized by the failure of the lower oesophageal sphincter (LES) relaxation and aperistalsis, caused primarily by the loss of the inhibitory innervation of the oesophageal myenteric plexus.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 128
Correct
-
Which factor produced by the endothelium is responsible for the regulation of vascular cell growth?
Your Answer: Vascular endothelial growth factor (VEGF)
Explanation:VEGF is produced by the endothelial cells and is the major growth factor responsible for causing vasculogenesis. Some isoforms of this growth factor also have a prominent role in formation of lymphatic vessels.
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This question is part of the following fields:
- Cardiovascular
- Medicine
-
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Question 129
Correct
-
Type 2 hypersensitivity is mediated by:
Your 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 130
Correct
-
Which cells produce the immunoglobulin proteins involved in mediating humoral immunity?
Your Answer: Differentiated forms of B lymphocytes known as plasma cells
Explanation:After the B cells have been activated by a certain antigens, they transform into plasma cells. These plasma cells are responsible for the generation of antibodies (or immunoglobulins Ig) which are also known as regulators of humoral immunity. There are fives classes of Ig: IgA, IgG, IgM, IgE and IgD
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This question is part of the following fields:
- Immunology
- Medicine
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Question 131
Incorrect
-
Intermediate filaments achieve cell to cell contact via:
Your Answer: Hemidesmosomes
Correct Answer: Desmosomes
Explanation:At the plasma membrane, some keratins interact with desmosomes (cell-cell adhesion) and hemidesmosomes (cell-matrix adhesion) via adapter proteins.
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This question is part of the following fields:
- Cell Biology
- Medicine
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Question 132
Incorrect
-
Where is the lower border of the liver usually found?
Your Answer: 10th rib midclavicular line on right
Correct Answer: 10th rib anterior axillary line on right
Explanation:Assessment of liver margins is important clinically to determine the size of the liver and is done via percussion during the physical examination. The liver typically extends from the fifth intercostal space or 6th rib to the right costal margin in the midclavicular line and the 10th rib on anterior axillary line.
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This question is part of the following fields:
- Hepatobiliary
- Medicine
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Question 133
Correct
-
Question 134
Correct
-
During which phase of meiosis does exchange of genetic material occur accounting for genetic diversity between individuals:
Your Answer: Prophase 1
Explanation:Prophase 1 has been divided into five different stages ( laptotene, zygotene, pachytene, diplotene ans diakinesis). In prophase 1 chromosomes are going to condense to become visible, each chromosome will contain two chromatids that are joined at the centromere. the nucleolus and nuclear envelope are going to disintegrate. the homologous chromosomes will form tetrad and crossing over will occur between the chromosomes (random exchange of genes), the point of exchange is known as the chiasmata, this increases genetic diversity.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 135
Correct
-
β-blockers are used in the treatment of angina because they have which one of the following properties?
Your Answer: Decrease the heart rate and myocardial contractility
Explanation:The cardiovascular effects of β-adrenoceptor block result from reduction of the sympathetic drive which includes reduced heart rate (automaticity) and reduced myocardial contractility (rate of rise of pressure in the ventricle). This will lead to reduced cardiac output and an overall fall in oxygen consumption.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 136
Correct
-
Which one of these features is typical of dermatomyositis?
Your Answer: Gottron's papules over knuckles of fingers
Explanation:Dermatomyositis is a long-term inflammatory disorder which affects muscles. Its symptoms are generally a skin rash and worsening muscle weakness in the proximal muscles (for example, the shoulders and thighs) over time. These may occur suddenly or develop over months. Other symptoms may include weight loss, fever, lung inflammation, or light sensitivity. Complications may include calcium deposits in muscles or skin.The skin rash may manifest as aheliotrope (a purplish color) or lilac, but may also be red. It can occur around the eyes along with swelling, as well as the upper chest or back ( shawl sign) or V-sign above the breasts and may also occur on the face, upper arms, thighs, or hands. Another form the rash takes is called Gottron’s sign which are red or violet, sometimes scaly, slightly raised papules that erupt on any of the finger joints (the metacarpophalangeal joints or the interphalangeal joints)
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This question is part of the following fields:
- Dermatology
- Medicine
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Question 137
Correct
-
Which statement about X linked dominant disorders is FALSE?
Your Answer: Heterozygous females tend to have the disease more severely than affected males.
Explanation:Women who have the affected X chromosome will be affected, but the severity will be less than that in males as they have a normal X chromosome to counter the effect of the mutated X chromosome. Affected males will pass on the defect to their daughters 100% of the time but not to their sons.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 138
Correct
-
“Ploidy” is a term used to refer to the number of chromosomes in cells. Cancer cells are commonly:
Your Answer: Aneuploidy
Explanation:Cancer cells most commonly undergo disordered cell growth and cell division. This results in an additional number of chromosomes called aneuploidy. This is a characteristic of cancer cells along with variation in differentiation of the cells.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 139
Incorrect
-
Vagotomy leads to the following:
Your Answer: Indigestion
Correct Answer: Irregular and chaotic peristalsis
Explanation:The Vagus nerve is primarily responsible for autonomic regulation involved in heart, lung and gastrointestinal function. The gastric branches supply the stomach. The right branch joins the celiac plexus and supplies the intestines. Vagotomy involves cutting of the vagus nerve or its branches which is a now-obsolete therapy that was performed for peptic ulcer disease. Vagotomy causes a decrease in peristalsis and a change in the emptying patterns of the stomach.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
-
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Question 140
Incorrect
-
During anaerobic glycolysis, the net production of ATP is:
Your Answer: 6
Correct Answer: 2
Explanation:Anaerobic glycolysis is the transformation of glucose to lactate when limited amounts of oxygen (O2) are available. Anaerobic glycolysis is only an effective means of energy production during short, intense exercise, providing energy for a period ranging from 10 seconds to 2 minutes. It produces 2 ATP molecules per glucose molecule.
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This question is part of the following fields:
- Medicine
- Metabolism
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Question 141
Incorrect
-
Regarding cardiac muscle contractility, the afterload refers to:
Your Answer: The degree of myocardial stretch before contraction
Correct Answer: The resistance against which blood is expected
Explanation:The afterload for the left ventricle is the aortic pressure. Hence it is this pressure that offers resistance against which the blood is to be expelled from the heart.
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This question is part of the following fields:
- Cardiovascular
- Medicine
-
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Question 142
Correct
-
All valves are closed in which phase of the cardiac cycle?
Your Answer: Isovolumetric relaxation
Explanation:The cardiac cycle refers to a complete heartbeat from its generation to the beginning of the next beat, and so includes the diastole, the systole, and the intervening pause.The first stage, diastole, is when the semilunar valves (the pulmonary valve and the aortic valve) close, the atrioventricular (AV) valves (the mitral valve and the tricuspid valve) open, and the whole heart is relaxed. The second stage, atrial systole, is when the atrium contracts, and blood flows from atrium to the ventricle.The third stage, isovolumic contraction is when the ventricles begin to contract, the AV and semilunar valves close, and there is no change in volume. The fourth stage, ventricular ejection, is when the ventricles are contracting and emptying, and the semilunar valves are open. During the fifth stage, isovolumic relaxation time, pressure decreases, no blood enters the ventricles, the ventricles stop contracting and begin to relax, and the semilunar valves close due to the pressure of blood in the aorta.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 143
Correct
-
Which of the following is least recognised as a potential complication of acromegaly?
Your Answer: Mental retardation
Explanation:Acromegaly is a condition that results from excess growth hormone (GH) after the growth plates have closed. It is typically due to the pituitary gland producing too much growth hormone. In more than 95% of people the excess production is due to a benign tumour, known as a pituitary adenoma. The condition is not inherited.Complications:Severe headacheArthritis and carpal tunnel syndromeEnlarged heartLiver fibrosis and bile duct hyperplasiaHypertensionDiabetes mellitus (excess of GH leads to insulin resistance)Heart failureKidney failureColorectal cancerCompression of the optic chiasm leading to loss of vision in the outer visual fields (typically bitemporal hemianopia.)Increased palmar sweating and sebum production over the face (seborrhoea) are clinical indicators of active GH-producing pituitary tumours.hypertensiondiabetes (>10%)cardiomyopathycolorectal cancer
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This question is part of the following fields:
- Endocrinology
- Medicine
-
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Question 144
Correct
-
Which of the following treatments would you advise for a young, 21 year old student who has ankylosing spondylitis and complains of worsening back pain and morning stiffness?
Your Answer: Oral NSAIDs
Explanation:NSAIDs are considered as the first line of treatment for managing pain and stiffness associated with ankylosing spondylitis. Other useful medications include TNF-alpha inhibitors. Other drugs like paracetamol, colchicine, and steroids are not routinely used. Bilateral total hip replacement might be indicated in advanced disease contrary to complicated spinal surgery.
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This question is part of the following fields:
- Connective Tissue
- Medicine
-
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Question 145
Incorrect
-
A case-control study is developed to assess passive smoking as a risk factor for the development of asthma in children. The total number of patients recruited for this study is 200. 40 out of the 200 patients report at least one parent smoking in the house when they were younger. 200 more people without asthma are recruited and 20 out of them report that at least one parent smoked in the house when they were younger. What is the odds ratio of patients with asthma having been exposed to passive smoking during their childhood?
Your Answer: 0.5
Correct Answer: 2.25
Explanation:An odds ratio (OR) is a measure of association between an exposure and an outcome. The OR represents the odds that an outcome will occur given a particular exposure, compared to the odds of the outcome occurring in the absence of that exposure. Odds ratios are most commonly used in case-control studies, however they can also be used in cross-sectional and cohort study designs as well (with some modifications and/or assumptions). Wherea = Number of exposed casesb = Number of exposed non-casesc = Number of unexposed casesd = Number of unexposed non-casesOR=(a/c) / (b/d) = ad/bc
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This question is part of the following fields:
- Medicine
- Research Skills
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Question 146
Correct
-
Interruption of the left optic tract will result in which visual field defect?
Your Answer: Right homonymous hemianopia
Explanation:Right homonymous hemianopia is due to a lesion or pressure on the left optic tract. Total blindness of the left eye is due to a complete occlusion of the left optic nerve. Bipolar hemianopia is due to a midline chiasmal lesion. Left nasal hemianopia due to a lesion involving the left perichiasmal area. Right homonymous inferior quadrantanopia is due to involvement of the lower left optic radiations.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 147
Incorrect
-
Which of the following results in the resting membrane potential of a myocyte?
Your Answer: Activation of fast Na channels
Correct Answer: Activation of outward K+ channels
Explanation:Phase 0 is caused by the sodium current. Voltage gated sodium channels open leading to the influx of sodium into the cardiac muscle cell. Phase 1 is the rapid transient repolarization phase which is caused by the inactivation of the voltage gated sodium channels and opening of the voltage gated potassium channels along with opening of the slow calcium channels. Phase 2 which is the plateau is caused by opening of the slow calcium channels. Phase 4 is caused by closing of the slow calcium channels and opening of the potassium channels leading to efflux of potassium leading to the establishment of the resting membrane potential.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 148
Incorrect
-
Which one of the following is able to move across cell membranes by passive diffusion?
Your Answer: Glucose
Correct Answer: CO2
Explanation:The cell membrane is permeable to water molecules and a few other small, uncharged, molecules like oxygen (O2) and carbon dioxide (CO2). Larger molecules like glucose or charged ions are unable to cross passively.
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This question is part of the following fields:
- Cell Biology
- Medicine
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Question 149
Correct
-
Peristalsis is an example of:
Your Answer: Enteric nervous system
Explanation:Peristalsis is a type of contraction where radial symmetrical contraction and relaxation of muscles propagates food in a downward wave through the gut. The enteric nervous system is one of the main divisions of the nervous system and consists of a mesh-like system of neurons that controls the function of the gastrointestinal tract. It has an independent reflex activity. The neurons of this system re collected into two types of ganglia: myenteric (or Auerbach’s) and submucosal (or Meissner’s plexuses). Myenteric plexuses are located between the inner and outer layers of the muscularis externa, while submucosal plexuses are located in the submucosa.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 150
Incorrect
-
Which of the following is not a feature of Liddle’s syndrome?
Your Answer:
Correct Answer: Autosomal recessive inheritance
Explanation:Liddle’s syndrome is a rare autosomal dominant condition characterized by early, and frequently severe, high blood pressure associated with low plasma renin activity, metabolic alkalosis, low blood potassium, and normal to low levels of aldosterone. Liddle syndrome involves abnormal kidney function, with excess reabsorption of sodium and loss of potassium from the renal tubule, and is treated with a combination of low sodium diet and potassium-sparing diuretic drugs (e.g., amiloride).
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This question is part of the following fields:
- Endocrinology
- Medicine
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SESSION STATS - PERFORMANCE PER SPECIALTY
