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Question 1
Correct
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What is the mechanism of action of sildenafil citrate?
Your Answer: Inhibition of phosphodiesterase V
Explanation:Sildenafil citrate (Viagra) is the first oral drug to be widely approved for the treatment of erectile dysfunction. It is a potent and selective inhibitor of type-V phosphodiesterase, the primary form of the enzyme found in human penile erectile tissue, thereby preventing the breakdown of cyclic guanosine monophosphate (cGMP), the intracellular second messenger of nitric oxide.Uses:It is used for the treatment of erectile dysfunction, idiopathic pulmonary hypertension, premature ejaculation, high altitude illness, penile rehabilitation after radical prostatectomy, angina pectoris, and lower urinary tract symptoms.Adverse effects:Mild headache, flushing, dyspepsia, cyanopsia, back pain, and myalgias – due to a high concentration of PDE11 enzyme in skeletal muscle, which shows significant cross-reactivity with the use of tadalafil.It can also cause hypotension, dizziness, and rhinitis.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 2
Incorrect
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What is the most abundant hormone release by the thyroid?
Your Answer: T3
Correct Answer: T4
Explanation:T3 and T4 are the two tyrosine-based hormones produced and secreted by the thyroid gland. Although T3 is the active form of the hormone, and thus, it is much more potent; T4 is the most abundant hormone secreted by the thyroid (93% of the total thyroid secretion) and it also has a longer half life since it binds to proteins much more strongly.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 3
Correct
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How does pregnancy affect the cardiac output of a patient?
Your Answer: Increased cardiac output due to increase in heart rate and stroke volume
Explanation:Cardiac Output increases to a similar degree as the blood volume. During the first trimester cardiac output is 30-40% higher than in the non-pregnant state. Steady rises are shown on Doppler echocardiography, from an average of 6.7 litres/minute at 8-11 weeks to about 8.7 litres/minute flow at 36-39 weeks; they are due, primarily, to an increase in stroke volume (35%) and, to a lesser extent, to a more rapid heart rate (15%). There is a steady reduction in systemic vascular resistance (SVR) which contributes towards the hyperdynamic circulation observed in pregnancy
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 4
Incorrect
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Calcium is transported over the brush border in the gut, via which transporter / channel?
Your Answer: TRPV 5
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 5
Correct
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In the cardiac cycle, all of the following are true except:
Your Answer: Mitral valve is closed by contraction of papillary muscles
Explanation:Mitral valve is closed by contraction of papillary muscles: This statement is incorrect. The mitral valve closes due to the pressure difference between the left ventricle and the left atrium at the onset of ventricular systole. The papillary muscles contract to prevent prolapse of the valve into the atrium but do not cause the valve to close.
The left ventricular volume is maximal at the end of atrial systole: This statement is true. At the end of atrial systole, the atria have pushed the remaining blood into the ventricles, making the ventricular volume maximal (end-diastolic volume).
The left ventricular pressure is maximal just before the aortic valve opens: This statement is true. Left ventricular pressure peaks just before the aortic valve opens, as the ventricle contracts to overcome the pressure in the aorta.
The ejection fraction is about 55%: This statement is true. The ejection fraction, which is the percentage of blood ejected from the ventricles with each contraction, is typically around 55%.
The ‘a’ wave is due to atrial systole: This statement is true. The ‘a’ wave on the venous pressure curve corresponds to atrial systole, reflecting the increased pressure from atrial contraction.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 6
Correct
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All of the following constitute small intestinal brush border enzymes except:
Your Answer: Alpha-amylase
Explanation:The final step in digestion of carbohydrates, which is conversion of disaccharides to absorbable monosaccharides occurs on the small intestinal epithelial cells. The enzymes responsible for this final stage of digestion are not freely found in the intestinal lumen, but they are found as integral membrane proteins in the plasma membrane of the epithelial cell. The apical plasma membrane of the intestinal epithelial cell has numerous microvilli which extend from the cell known as the brush border. Thus, the enzymes embedded in those microvilli are referred to as brush border enzymes. All these enzymes except alfa amylase are brush border enzymes. Alfa amylase is secreted by pancreatic acinar cells.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 7
Incorrect
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Which one of the following is not part of the WHO diagnostic criteria for the metabolic syndrome?
Your Answer: Low HDL
Correct Answer: High LDL
Explanation:The World Health Organization 1999 criteria require the presence of any one of diabetes mellitus, impaired glucose tolerance, impaired fasting glucose or insulin resistance, AND two of the following:
- Blood pressure: ≥ 140/90 mmHg
- Dyslipidaemia: triglycerides (TG): ≥ 1.695 mmol/L and high-density lipoprotein cholesterol (HDL-C) ≤ 0.9 mmol/L (male), ≤ 1.0 mmol/L (female)
- Central obesity: waist: hip ratio > 0.90 (male); > 0.85 (female), or body mass index > 30 kg/m2
- Microalbuminuria: urinary albumin excretion ratio ≥ 20 µg/min or albumin: creatinine ratio ≥ 30 mg/g
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 8
Correct
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The lamina propria contains all of the following except:
Your 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 9
Correct
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A 25-year-old male presents to the emergency department with fever, sweating, hyperventilation and breathing difficulty. He also complains of a continuous ringing sensation in both his ears for the past couple of days. He admits to consuming a lot of over the counter painkillers for the past few days. Which of the following drugs is the most likely cause of these symptoms?
Your Answer: Aspirin
Explanation:The presence of tinnitus, fever and hyperventilation are clues for aspirin (salicylate) toxicity. Clinical Presentation of salicylate toxicity can include:• Pulmonary manifestations include: Hyperventilation, hyperpnea, severe dyspnoea due to noncardiogenic pulmonary oedema, fever and dyspnoea due to aspiration pneumonitis• Auditory symptoms caused by the ototoxicity of salicylate poisoning include: Hard of hearing and deafness, and tinnitus (commonly encountered when serum salicylate concentrations exceed 30 mg/dL).• Cardiovascular manifestations include: Tachycardia, hypotension, dysrhythmias – E.g., ventricular tachycardia, ventricular fibrillation, multiple premature ventricular contractions, asystole – with severe intoxication, Electrocardiogram (ECG) abnormalities – E.g., U waves, flattened T waves, QT prolongation may reflect hypokalaemia.• Neurologic manifestations include: CNS depression, with manifestations ranging from somnolence and lethargy to seizures and coma, tremors, blurring of vision, seizures, cerebral oedema – With severe intoxication, encephalopathy• GI manifestations include: Nausea and vomiting, which are very common with acute toxicity, epigastric pain, GI haemorrhage – More common with chronic intoxication, intestinal perforation, pancreatitis, hepatitis – Generally in chronic toxicity; rare in acute toxicity, Oesophageal strictures – Reported as a very rare delayed complication• Genitourinary manifestations include: Acute kidney injury (NSAID induced Nephropathy) is an uncommon complication of salicylate toxicity, renal failure may be secondary to multisystem organ failure.• Hematologic effects may include prolongation of the prothrombin and bleeding times and decreased platelet adhesiveness. Disseminated intravascular coagulation (DIC) may be noted with multisystem organ failure in association with chronic salicylate toxicity.• Electrolyte imbalances like: Dehydration, hypocalcaemia, acidaemia, Syndrome of inappropriate antidiuretic hormone secretion (SIADH), hypokalaemiaManagement of these patients should be done in the following manner:• Secure Airway, Breathing, and Circulation• Supportive therapy• GI decontamination• Urinary excretion and alkalization• Haemodialysis
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 10
Correct
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A 32 year old man presents with blistering and hyperpigmentation on his face and hands, after a beach holiday with friends. Tests reveal high levels of uroporphyrinogen in the urine. The most likely diagnosis is:
Your Answer: Porphyria cutanea tarda
Explanation:Porphyria cutanea tarda (PCT) is the most common of the porphyries. It is characterised by fragility and blistering of exposed skin. Typically, patients who are ultimately diagnosed with PCT first seek treatment following the development photosensitivities in the form of blisters and erosions on commonly exposed areas of the skin. This is usually observed in the face, hands, forearms, and lower legs. It heals slowly and with scarring. Though blisters are the most common skin manifestations of PCT, other skin manifestations like hyperpigmentation (as if they are getting a tan) and hypertrichosis (mainly on top of the cheeks) also occur. Risk factors for the development of PCT include alcohol and sun.
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This question is part of the following fields:
- Dermatology
- Medicine
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Question 11
Correct
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In Restriction Fragment Length Polymorphism (RFLP), the DNA fragments are separated by length through a process known as:
Your Answer: Gel electrophoresis
Explanation:Samples of DNA from individuals are broken into pieces by restriction enzymes and the fragments are separated according to their lengths via gel electrophoresis. Although now largely obsolete due to the rise of inexpensive DNA sequencing technologies, RFLP analysis was the first DNA profiling technique inexpensive enough to see widespread application.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 12
Correct
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Question 13
Incorrect
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With regard to the spleen which of the following has the correct match?
Your Answer: Malpighian corpuscle - red pulp
Correct Answer: Periarteriolar lymphoid sheets - T lymphocytes
Explanation:The spleen consists of:Red pulp – responsible for mechanical filtration of red blood cells. Red pulp contains sinusoids, which are filled with blood, splenic cords of reticular fibers and a marginal zoneWhite pulp – responsible for active immune response through humoral and cell-mediated pathways. Composed of nodules, called Malpighian corpuscles. These are composed of: lymphoid follicles, rich in B-lymphocytes and periarteriolar lymphoid sheaths, rich in T-lymphocytes
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This question is part of the following fields:
- Haematology
- Medicine
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Question 14
Correct
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Which mechanism of action does Penicillin use?
Your Answer: Inhibit cell wall synthesis
Explanation:Bacteria constantly remodel their peptidoglycan cell walls, simultaneously building and breaking down portions of the cell wall as they grow and divide. β-Lactam antibiotics inhibit the formation of peptidoglycan cross-links in the bacterial cell wall; this is achieved through binding of the four-membered β-lactam ring of penicillin to the enzyme DD-transpeptidase. As a consequence, DD-transpeptidase cannot catalyse formation of these cross-links, and an imbalance between cell wall production and degradation develops, causing the cell to rapidly die.
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This question is part of the following fields:
- Infectious Diseases
- Medicine
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Question 15
Correct
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If both the noradrenergic and the cholinergic systems are blocked in the heart, the rate will be approximately:
Your Answer: 100/min
Explanation:The normal heart beat is about 70/min. This is due to a predominant parasympathetic activity. If sympathetic activity was unopposed the heart rate would have been 150/min. When both the noradrenergic and cholinergic systems are blocked the heart rate is 100/min. This is the normal firing rate of the SA node.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 16
Correct
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Telomerase is active in the following cells except:
Your Answer: Certain osteoblasts
Explanation:Some cells have the ability to reverse telomere shortening by expressing telomerase, an enzyme that extends the telomeres of chromosomes. Telomerase is an RNA-dependent DNA polymerase, meaning an enzyme that can make DNA using RNA as a template.
Telomerase is not usually active in most somatic cells (cells of the body), but it’s active in germ cells (the cells that make sperm and eggs) and some adult stem cells. These are cell types that need to undergo many divisions, or, in the case of germ cells, give rise to a new organism with its telomeric “clock” reset.Interestingly, many cancer cells have shortened telomeres, and telomerase is active in these cells. If telomerase could be inhibited by drugs as part of cancer therapy, their excess division (and thus, the growth of the cancerous tumor) could potentially be stopped.A subset of liver cells with high levels of telomerase renews the organ during normal cell turnover and after injury. -
This question is part of the following fields:
- Genetics
- Medicine
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Question 17
Incorrect
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Regarding Southern Blotting and DNA probes, which answer is FALSE
Your Answer: DNA fragments are separated by gel electrophoresis and transferred onto membrane sheets in southern blotting
Correct Answer: RNA fragments are separated by gel electrophoresis and transferred onto membrane sheets in southern blotting
Explanation:Restriction enzymes always cut at different positions. There are different restriction endonucleases for different nucleotide sequences.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 18
Correct
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Question 19
Correct
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In addition to its role in digestion and absorption of fats, bile:
Your Answer: Is the major excretory route for lipid-soluble waste products
Explanation:The end product of haem metabolism is bilirubin and jaundice is caused by increased bilirubin levels in the blood. Gallstones are mainly caused by cholesterol and bile pigments. Bile is the main route of excretion for lipid soluble waste products whereas urine is the main route of excretion of water soluble waste products.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 20
Correct
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Which statement is incorrect?
Your Answer: Translation begins when the triplet (UGA) encoding for methionine is encountered.
Explanation:Translation being when the codon for methionine is encountered which is AUG not UGA. This process is known as initiation. All the other options are correct.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 21
Incorrect
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Which of the following features occurs very less frequently with drug induced lupus?
Your Answer: Pleurisy
Correct Answer: Glomerulonephritis
Explanation:Drug induced lupus typically presents with pulmonary involvement and no renal or neurological involvement. Hence glomerulonephritis would be highly unlikely in this case. Rash and arthralgias are classic presentations. Pleurisy can be present as pulmonary involvement may occur with DILE.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 22
Incorrect
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Which cell secretes parathyroid hormone?
Your Answer:
Correct Answer: Chief cells
Explanation:Parathyroid chief cells, also known as parathyroid principal cells or parathyroid cells, are the most prevalent type of cell in the parathyroid gland and the only ones present at birth. They secrete parathyroid hormone (PTH).
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 23
Incorrect
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Which lipoprotein is responsible for lowering of plasma lipids?
Your Answer:
Correct Answer: HDL
Explanation:High-density lipoproteins (HDL) are one of the five major groups of lipoproteins. Lipoproteins are complex particles composed of multiple proteins which transport all fat molecules (lipids) around the body within the water outside cells. Unlike the larger lipoprotein particles which deliver fat molecules to cells, HDL particles remove fat molecules from cells.
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This question is part of the following fields:
- Medicine
- Metabolism
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Question 24
Incorrect
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Question 25
Incorrect
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Which of the following skin coloration abnormalities occurs due to adrenal insufficiency due to primary adrenal disease?
Your Answer:
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 26
Incorrect
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A 43 year old man with hemochromatosis presents with a painful and swollen right knee. X-ray shows extensive chondrocalcinosis but no fracture. Given the most likely diagnosis, which of the following would be present in the joint fluid aspirate?
Your Answer:
Correct Answer: Positively birefringent rhomboid-shaped crystals
Explanation:Pseudogout is a paroxysmal joint inflammation due to calcium pyrophosphate crystal deposition (calcium pyrophosphate dihydrate). Arthrocentesis should be performed, especially in acute cases. Polarized light microscopy: detection of rhomboid-shaped, positively birefringent CPPD crystals. Synovial fluid findings: 10,000-50,000 WBCs/μL with > 90% neutrophils. X-ray findings: cartilage calcification of the affected joint (chondrocalcinosis). Fibrocartilage (meniscus, annulus fibrosus of intervertebral disc) and hyaline cartilage (joint cartilage) may be affected.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 27
Incorrect
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The ENaC Transporter occurs in which part of the renal tubule?
Your Answer:
Correct Answer: Collecting duct
Explanation:The epithelial sodium channel (ENaC) is a membrane-bound ion channel that is selectively permeable to Na+ ions. It is involved primarily in the reabsorption of sodium ions at the collecting ducts of the kidney’s nephrons.
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This question is part of the following fields:
- Medicine
- Renal
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Question 28
Incorrect
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With regard to carbohydrate absorption, which sodium-dependent glucose transporter (SGLT) is responsible for the uptake of dietary glucose from the gut?
Your Answer:
Correct Answer: SGLT 1
Explanation:SGLT- Sodium-dependent glucose cotransporter or sodium-glucose linked transporter are family of proteins of different types. SGLT1 transporter is found in the intestinal mucosa of the small intestine.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 29
Incorrect
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The following products of the vascular endothelium produce vasodilation except:
Your Answer:
Correct Answer: Endothelin
Explanation:Endothelin: This is incorrect in the context of vasodilation. Endothelin is actually a potent vasoconstrictor produced by the endothelium, leading to the narrowing of blood vessels and increased blood pressure.
Nitrous oxide (Nitric oxide): This is correct for vasodilation. Nitric oxide is a powerful vasodilator produced by the endothelium, which helps relax and widen blood vessels.
Prostacyclin: This is correct for vasodilation. Prostacyclin (PGI2) is a vasodilator and inhibits platelet aggregation, helping to maintain blood flow and reduce clot formation.
Endothelial-derived hyperpolarizing factor (EDHF): This is correct for vasodilation. EDHF causes vasodilation by hyperpolarizing the smooth muscle cells of blood vessels.
Vascular endothelial growth factor (VEGF): This is correct for vasodilation. VEGF primarily promotes the growth of new blood vessels but also has vasodilatory effects through nitric oxide production.
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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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An 18 year old girl presents with short history of marked, right hip pain and an associated limp. She has a history of acute lymphoblastic leukaemia for which she completed treatment for last six months.
Your Answer:
Correct Answer: Avascular necrosis of the femoral head
Explanation:Avascular necrosis (AVN) of the femoral head is a pathological process that results from disruption of the blood supply to the bone and occurs most commonly in the femoral epiphysis. Patients usually present with pain and limited joint motion. The mechanism involves impaired circulation to a specific area that ultimately becomes necrotic. AVN is most frequently associated with high doses of oral and intravenous corticosteroids and prolonged duration of therapy. Cancer patients receiving chemotherapy are usually also treated with corticosteroids.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 31
Incorrect
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What is the correct formula to calculate the positive predictive value?(TP = true positive; FP = false positive; TN = true negative; FN = false negative)
Your Answer:
Correct Answer: TP / (TP + FP)
Explanation:Positive predictive value is the probability that subjects with a positive screening test truly have the disease.Positive predictive value = true positive / ( true positive + false positive)
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This question is part of the following fields:
- Medicine
- Research Skills
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Question 32
Incorrect
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Which of the atrial pressure changes represents the a-wave of the JVP
Your Answer:
Correct Answer: Atrial systole
Explanation:The a-wave created on the venous pulse curve occurs as a result of atrial systole. Due to the pressure build-up in the atria, it causes a back pressure in the vena cava. This pressure is exerted on the valve and this back pressure is what causes a slight increase in the venous pressure.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 33
Incorrect
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The process whereby DNA fragments are separated by size and charge is called:
Your Answer:
Correct Answer: Gel electrophoresis
Explanation:Fragments of DNA of varying length can be separated on the basis of their charge and their size by a process called gel electrophoresis. Because DNA contains negatively charged phosphate groups, it will migrate in an electric field toward the positive electrode. Shorter chains migrate more rapidly through the pores of the gel, and thus separation depends on length. DNA bands in the gel can be visualized by various techniques including staining with dyes and autoradiography.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 34
Incorrect
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A 79-year-old woman has a waddling gait. History reveals enuresis and change in behaviour. What is the most likely diagnosis?
Your Answer:
Correct Answer: Normal pressure hydrocephalus
Explanation:The waddling gait and behaviour change are attributes of normal pressure hydrocephalus along with loss of bladder control which commonly happens with elder age.
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This question is part of the following fields:
- Geriatrics
- Medicine
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Question 35
Incorrect
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Which of the given adverse effects should be anticipated following the administration of an anticholinesterase?
Your Answer:
Correct Answer: Bradycardia and miosis
Explanation:Bradycardia and miosis should be anticipated following the administration of anticholinesterases.Anticholinesterase agents include the following medications:- Pyridostigmine, neostigmine, and edrophonium which play a significant role in the diagnosis and the management of myasthenia gravis.- Rivastigmine, galantamine and donepezil are cholinesterase inhibitors found to be significantly useful in the management of Alzheimer’s disease.Mechanism of action and pharmacological effects:Inhibition of cholinesterase increases the level and the duration of action of acetylcholine within the synaptic cleft. Thus, cholinergic effects such as a reduction in heart rate (bradycardia), miosis (pupillary constriction), increased secretions, increased gastrointestinal motility and reduction in BP may occur with anticholinesterases.Toxins such as organophosphates and carbamates also are primarily anticholinergic and cause the following typical SLUDGE symptoms:- Salivation- Lacrimation- Urination- Diaphoresis- Gastrointestinal upset- Emesis
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 36
Incorrect
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The inverse stretch reflex causing muscle relaxation when excessive force is applied to a muscle is mediated by which sensory organ?
Your Answer:
Correct Answer: Golgi tendon organ
Explanation:Both the muscle spindle and Golgi tendon body are proprioceptors. The Golgi tendon reflex is a normal component of the reflex arc of the peripheral nervous system. In a Golgi tendon reflex, skeletal muscle contraction causes the antagonist muscle to simultaneously lengthen and relax. This reflex is also called the inverse myotatic reflex, because it is the inverse of the stretch reflex.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 37
Incorrect
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Stem cell characteristics include the following except
Your Answer:
Correct Answer: Differentiation and proliferation into progenitor cells committed to multiple cell lines
Explanation:The classical definition of a stem cell requires that it possess two properties:Self-renewal: the ability to go through numerous cycles of cell division while maintaining the undifferentiated state.Potency: the capacity to differentiate into specialized cell types. In the strictest sense, this requires stem cells to be either totipotent or pluripotent to be able to give rise to any mature cell type
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This question is part of the following fields:
- Haematology
- Medicine
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Question 38
Incorrect
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A 75 year old man presented to hospital after suffering a stroke. The doctor admitted him and advised of the Barthel score index. During rehabilitation, which one of the following limitations are best described by Barthel score index?
Your Answer:
Correct Answer: Floor and ceiling effects
Explanation:Barthel scoring has floor and ceiling effects which is the most widely recognised limitation. Floor effect means that the patient who is bed bound can score initially low, whereas the ceiling effect shows that despite being bed bound, a patient can achieve a maximum score i.e. 100. The test is easy to perform and correlates well with other prognostic scales.
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This question is part of the following fields:
- Geriatrics
- Medicine
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Question 39
Incorrect
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Question 40
Incorrect
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The cells that secrete pepsinogen and gastric lipase are found in which part of the stomach?
Your Answer:
Correct Answer: Body and fundus
Explanation:Stomach can be divided in to different regions. Cardia, fundus, body, antrum and pylorus from proximal end to distal end respectively. Cells that secret the inactive form of pepsin or pepsinogen are chief cells and are abundant in the body (corpus) and the fundus region of the stomach.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 41
Incorrect
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To which of the following plasma proteins is T4 most bound in plasma?
Your Answer:
Correct Answer: Thyroxine-binding globulin
Explanation:Thyroxine-binding globulin, also known as TBG, is one of the three transport proteins responsible for carrying T4 and T3 through the circulatory system. It carries most of the T4 present in plasma, which it binds to strongly, shielding the hydrophobic hormones from the aqueous surroundings.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 42
Incorrect
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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:
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 43
Incorrect
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Which one of the following statements regarding epidemiological measures is correct?
Your Answer:
Correct 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 44
Incorrect
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Which one of the following antibiotics is safest to use in pregnancy?
Your Answer:
Correct Answer: Erythromycin
Explanation:Antibiotics that should be avoided in pregnancy are included in the mnemonic: Countless SAFe Moms Take Really Good Care -Clarithromycin, Sulphonamides, Aminoglycosides, Fluoroquinolones, Metronidazole, Tetracyclines, Ribavirin, Griseofulvin, Chloramphenicol
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 45
Incorrect
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During anaerobic glycolysis, the net production of ATP is:
Your Answer:
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 46
Incorrect
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The functional unit of the liver is called?
Your Answer:
Correct Answer: Acini
Explanation:From a metabolic perspective, the functional unit is the hepatic acinus (terminal acinus), each of which is centred on the line connecting two portal triads and extends outwards to the two adjacent central veins. The periportal zone I is nearest to the entering vascular supply and receives the most oxygenated blood, making it least sensitive to ischemic injury while making it very susceptible to viral hepatitis. Conversely, the centrilobular zone III has the poorest oxygenation, and will be most affected during a time of ischemia.
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This question is part of the following fields:
- Hepatobiliary
- Medicine
-
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Question 47
Incorrect
-
Which one of the following neurotransmitters is considered a monoamine?
Your Answer:
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 48
Incorrect
-
A 35-year-old female has been recently diagnosed with hypertension. She's sexually active and is not using any birth control other than barrier method. Which among the following antihypertensives is contraindicated in this patient?
Your Answer:
Correct Answer: Lisinopril
Explanation:Among the following hypertensives, lisinopril (an ACE inhibitor) is contraindicated in patients who are planning for pregnancy.Per the NICE guidelines, when treating the woman in question, she should be treated as if she were pregnant given the absence of effective contraception. ACE inhibitors such as lisinopril are known teratogens and most be avoided.Drugs contraindicated in pregnancy:AntibioticsTetracyclinesAminoglycosidesSulphonamides and trimethoprimQuinolonesOther drugs:ACE inhibitors, angiotensin II receptor antagonistsStatinsWarfarinSulfonylureasRetinoids (including topical)Cytotoxic agentsThe majority of antiepileptics including valproate, carbamazepine, and phenytoin are known to be potentially harmful.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 49
Incorrect
-
What is the mechanism of action of carbimazole?
Your Answer:
Correct Answer: Inhibition of the iodination of tyrosine
Explanation:Carbimazole is used to treat hyperthyroidism. Carbimazole is a pro-drug as after absorption it is converted to the active form, methimazole. Methimazole prevents thyroid peroxidase enzyme from coupling and iodinating the tyrosine residues on thyroglobulin, hence reducing the production of the thyroid hormones T3 and T4 (thyroxine).
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This question is part of the following fields:
- Medicine
- Pharmacology
-
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Question 50
Incorrect
-
Regarding carbohydrates absorption;
Your Answer:
Correct Answer: Intestinal absorption of sugars is inhibited by the drug phlorizin
Explanation:The main role of insulin is in the uptake of glucose from blood to tissues where it is metabolised. Glycose transporters in the intestines do not depend on the action of insulin. Phlorizin is a competitive inhibitor of SGLT1 and SGLT2 because it competes with glucose for the binding site, reducing intestinal and renal glucose transport.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 51
Incorrect
-
Where in the course of the gastrointestinal tract does the first significant digestion of fat begin in a normal human being?
Your Answer:
Correct Answer: Duodenum
Explanation:The enzyme lipase which is responsible for digestion of fat is secreted by the exocrine pancreas in the 2nd part of the duodenum at the point where the pancreatic duct opens. It opens together with the common bile duct which contains bile that emulsify fat aiding in digestion. The oesophagus, stomach and mouth do not contain enzymes related to fat digestion.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
-
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Question 52
Incorrect
-
The following play a role in regulation of intestinal iron absorption except:
Your Answer:
Correct Answer: Urinary iron excretion rate
Explanation:The human body’s rate of iron absorption appears to respond to a variety of interdependent factors, including total iron stores, dietary intake, the extent to which the bone marrow is producing new red blood cells, the concentration of haemoglobin in the blood, and the oxygen content of the blood. Classic examples of genetic iron overload includes hereditary hemochromatosis (HH) and the more severe disease juvenile hemochromatosis (JH).
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This question is part of the following fields:
- Haematology
- Medicine
-
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Question 53
Incorrect
-
Why does arterial blood pressure drop during pregnancy?
Your Answer:
Correct Answer: Progesterone relaxes vascular smooth muscle
Explanation:Progesterone relaxes vascular smooth muscle thus resulting In a decrease in total peripheral resistance. This accounts for the increase in the cardiac output.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 54
Incorrect
-
The direct determinants of cardiac output are
Your Answer:
Correct Answer: Stroke volume and heart rate
Explanation:Cardiac output is classically defined alongside stroke volume (SV) and the heart rate (HR) as:Cardiac Output [L/min] = Stroke Volume [L/beat] x Heart Rate [beats/min]
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This question is part of the following fields:
- Cardiovascular
- Medicine
-
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Question 55
Incorrect
-
VIP, GIP and somatostatin play an inhibitory role in gastric acid secretion by inactivating?
Your Answer:
Correct Answer: G cells
Explanation:Gastrin is secreted from the G cells. VIP, GIP and somatostatin all inhibit acid production by inhibiting the G cells.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
-
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Question 56
Incorrect
-
Which substance is produced by anterograde neurons?
Your Answer:
Correct Answer: Nitric oxide
Explanation:Nitric oxide is thought to act as an anterograde neurotransmitter. Classically in the peripheral nervous system, it diffuses from a presynaptic nerve ending to the post synaptic effecter cell which is mainly smooth muscle cells in the gastrointestinal, respiratory and urogenital tracts.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
-
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Question 57
Incorrect
-
In the event of an overdose, haemodialysis is ineffective as a treatment modality for which of the following drugs?
Your Answer:
Correct Answer: Tricyclics
Explanation:Tricyclic compounds can’t be cleared by haemodialysis.Drugs that can be cleared with haemodialysis include: (BLAST)- Barbiturate- Lithium- Alcohol (inc methanol, ethylene glycol)- Salicylates- Theophyllines (charcoal hemoperfusion is preferable)Drugs which cannot be cleared with haemodialysis include:- Tricyclics- Benzodiazepines- Dextropropoxyphene (Co-proxamol)- Digoxin- Beta-blockers
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This question is part of the following fields:
- Medicine
- Pharmacology
-
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Question 58
Incorrect
-
Which of the following foods do NOT contain high levels of folate?
Your Answer:
Correct Answer: Yellow vegetables
Explanation:Folate naturally occurs in a wide variety of foods, including vegetables (particularly dark green leafy vegetables), fruits and fruit juices, nuts, beans, peas, dairy products, poultry and meat, eggs, seafood, grains, and some beers. Avocado, beetroot, spinach, liver, yeast, asparagus, and Brussels sprouts are among the foods with the highest levels of folate
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This question is part of the following fields:
- Haematology
- Medicine
-
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Question 59
Incorrect
-
Select the CORRECT statement regarding bile salts…
Your Answer:
Correct Answer: Are necessary for any bile acid secretion by hepatocytes.
Explanation:Bile salts stimulate bile secretion by the liver. Bile salts do not have an enzymatic action on digestion of fat but rather emulsify fat for the action of enzymes secreted mainly by the pancreas. Bile salts are polar cholesterol derivatives and are not derived from amino acids.
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This question is part of the following fields:
- Hepatobiliary
- Medicine
-
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Question 60
Incorrect
-
An 80-year-old woman with advanced COPD has been admitted to the medicine ward in an unconscious state. She appears to have an acute lower respiratory tract infection. After consulting with an anaesthesiologist it was concluded that she was not a candidate for intensive care unit admission and thus, a decision was made to start the patient on doxapram therapy. Which of the following best fits the characteristics of doxapram?
Your Answer:
Correct Answer: It is contraindicated in hyperthyroidism
Explanation:The two statements that fit the characteristics of doxapram are, epilepsy is a contraindication for doxapram use and concurrent use with theophylline may increase agitation.Doxapram is a central respiratory stimulant. In clinical practice, doxapram is usually used for patients who have an acute exacerbation of chronic obstructive pulmonary disease (COPD) who are unsuitable for admission to the intensive therapy unit for ventilatory support. Doxapram infusion may buy an extra 24 h to allow for recovery.Contraindications include: ischaemic heart disease, epilepsy, cerebral oedema, acute stroke, asthma, hypertension, hyperthyroidism, and pheochromocytoma. The infusion may worsen agitation and dyspnoea and lead to hypertension, nausea, vomiting and urinary retention.Drug interactions:Concomitant administration of doxapram and aminophylline (theophylline) can cause increased skeletal muscle activity, agitation, and hyperactivity.
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This question is part of the following fields:
- Medicine
- Pharmacology
-
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Question 61
Incorrect
-
Which of the following intercellular connections is important in endothelial barrier function?
Your Answer:
Correct Answer: Tight junctions
Explanation:Tight junctions surround the apical margins of the epithelial cells such as in the intestinal mucosa and the choroid plexus. They are also important to the endothelial barrier function. They are made up of ridges that adhere to each other strongly at the cell junction, obliterating the space completely between the cells.
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This question is part of the following fields:
- Cardiovascular
- Medicine
-
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Question 62
Incorrect
-
The cells that secrete HCL are found in which part of the stomach?
Your Answer:
Correct Answer: Body
Explanation:The stomach can be divided in to different regions. Cardia, fundus, body, antrum and pylorus from proximal end to distal end respectively. Different cell types are distributed accordingly among the regions of the stomach. Cells that secret HCl in the gastric mucosa are known as parietal cells and are abundant in the gastric body region. They have receptors for acetylcholine stimulated via the vagus nerve, histamine receptors and gastrin receptors which stimulate gastric acid secretion. G cells that secret gastrin are abundant in the antrum.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
-
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Question 63
Incorrect
-
In the olfactory pathway: Mitral cells project to five regions of the olfactory cortex. Which one of the following is not one of the five regions?
Your Answer:
Correct Answer: Posterior olfactory nucleus
Explanation:The olfactory system contains peripheral and central divisions which are connected by transduction structures. Peripheral division consists mainly of the nostrils, ethmoid bone, nasal cavity, and the olfactory epithelium. Olfactory neurons are receptor cells in the epithelium that detect odour molecules dissolved in the mucus and transmit information about the odour to the brain in a process called sensory transduction. Olfactory nerves and fibers transmit information about odours from the peripheral olfactory system to the central olfactory system of the brain. The main olfactory bulb transmits pulses to both mitral and tufted cells, which help determine odour concentration. These cells also note differences between highly similar odours and use that data to aid in later recognition. The cells are different with the mitral having low firing-rates and being easily inhibited by neighbouring cells, while tufted have high rates of firing and are more difficult to inhibit. The uncus houses the olfactory cortex which includes the piriform cortex, amygdala, olfactory tubercle, and para-hippocampal gyrus. Entorhinal cortex is an area of middle temporal lobe that has connection with the para-hippocampal gyrus.
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This question is part of the following fields:
- Medicine
- Neurology
-
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Question 64
Incorrect
-
Question 65
Incorrect
-
Arterioles stemming from the coronary artery can also empty into the heart directly via the:
Your Answer:
Correct Answer: Arteriosinusoidal vessels
Explanation: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. They include arteriosinusoidal vessels, which connect the arterioles to the heart chambers. The thebesian veins drain the capillaries into the chambers and the arterioluminal vessels drain small arteries directly into the chambers.
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This question is part of the following fields:
- Cardiovascular
- Medicine
-
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Question 66
Incorrect
-
The midbrain, medulla and pons, contain the following cranial nerve nuclei?
Your Answer:
Correct Answer: CN 3 - 12
Explanation:The cranial nerves (with the exception of I and II) originate in the brainstem, which includes the midbrain, the pons, and the medulla.
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This question is part of the following fields:
- Medicine
- Neurology
-
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Question 67
Incorrect
-
Glucose transport in the brain is mediated by:
Your Answer:
Correct Answer: GLUT 1
Explanation:The facilitative glucose transporter mediates the transport of glucose from blood into neurons and glia in the brain. The primary isoforms in the brain are GLUT1 detected at high concentrations.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 68
Incorrect
-
Regarding the innervation of cerebral blood vessels, which of the following triggers a vasoconstrictor effect?
Your Answer:
Correct Answer: Neuropeptide-Y
Explanation:Substance P is a potent vasodilator, VIP or vasoactive intestinal peptide has vasodilator properties in the intestines. PHM 27 is a potent calcitonin receptor agonist; endogenous analogue of human VIP. CGRP or Calcitonin Gene-Related Peptide is a vasodilator which is found to play an important role in migraines. Neuropeptide Y is a strong vasoconstrictor.
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This question is part of the following fields:
- Medicine
- Neurology
-
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Question 69
Incorrect
-
A 67 year old man reports weight loss. Labs show a raised alkaline phosphatase at 290 U/L (normal range 35-120). Plain radiographs reveal sclerotic lesions of the bone. Which of the following is the most likely cause of these findings?
Your Answer:
Correct Answer: Prostate cancer
Explanation:Osteoblastic (or sclerotic) bony metastases, characterized by deposition of new bone, present in prostate cancer, carcinoid, small cell lung cancer, Hodgkin lymphoma or medulloblastoma. The other cancers listed in the options are osteolytic.
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This question is part of the following fields:
- Connective Tissue
- Medicine
-
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Question 70
Incorrect
-
On a mountain the atmospheric pressure is 700 mmHg and the humidity close to zero, the partial pressure of oxygen is:
Your Answer:
Correct Answer: 147 mmHg
Explanation:Natural air includes approximately 21% of oxygen. If humidity is zero, the partial pressure of oxygen is 700 × 21% = 147 mmHg
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This question is part of the following fields:
- Medicine
- Respiratory
-
-
Question 71
Incorrect
-
With regards to environmental temperature, for each degree Celsius of elevation, the metabolic rate rises?
Your Answer:
Correct Answer: 0.14
Explanation:An increase in body temperature is associated with a higher metabolic rate. Evidence suggests that an increase of 1°C in your body temperature increases your metabolism by 10 to 14%.
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This question is part of the following fields:
- Medicine
- Metabolism
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Question 72
Incorrect
-
The complete oxidation of 1 molecule of glucose to CO2 and H20 produces a total of __ATP.
Your Answer:
Correct Answer: 38
Explanation:Textbooks often state that 38 ATP molecules can be made per oxidised glucose molecule during cellular respiration (2 from glycolysis, 2 from the Krebs cycle, and about 34 from the electron transport system). However, this maximum yield is never quite reached because of losses due to leaky membranes as well as the cost of moving pyruvate and ADP into the mitochondrial matrix, and current estimates range around 29 to 30 ATP per glucose.
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This question is part of the following fields:
- Cell Biology
- Medicine
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Question 73
Incorrect
-
Which of the following pairs are correct concerning arteriolar tone?
Your Answer:
Correct Answer: Hormonal control: catecholamines affect the adrenergic receptors of the vascular smooth muscle
Explanation:Catecholamines released from the adrenal medulla act on the noradrenergic receptors of the vascular smooth muscles. In the skeletal muscles and liver it causes vasodilation whilst it causes vasoconstriction in the rest of the blood vessels of the body.
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This question is part of the following fields:
- Cardiovascular
- Medicine
-
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Question 74
Incorrect
-
Café-au-lait spots are seen in each of the following, except:
Your Answer:
Correct Answer: Friedreich's ataxia
Explanation:Café-au-lait spots are hyperpigmented lesions that vary in colour from light brown to dark brown, with borders that may be smooth or irregular.
Causes include:
- Neurofibromatosis type I
- McCune–Albright syndrome
- Legius syndrome
- Tuberous sclerosis
- Fanconi anaemia
- Idiopathic
- Ataxia-telangiectasia
- Basal cell nevus syndrome
- Benign congenital skin lesion
- Bloom syndrome
- Chediak-Higashi syndrome
- Congenital nevus
- Gaucher disease
- Hunter syndrome
- Maffucci syndrome
- Multiple mucosal neuroma syndrome
- Noonan syndrome
- Pulmonary Stenosis
- Silver–Russell syndrome
- Watson syndrome
- Wiskott–Aldrich syndrome
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This question is part of the following fields:
- Dermatology
- Medicine
-
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Question 75
Incorrect
-
The pyloric sphincter is largely made up of thickening of
Your Answer:
Correct Answer: The circular muscle layer
Explanation:The pyloric sphincter, or valve, is a strong ring of smooth muscle (circular muscle layer) at the end of the pyloric canal which lets food pass from the stomach to the duodenum. It controls the outflow of gastric contents into the duodenum. It receives sympathetic innervation from the celiac ganglion.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
-
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Question 76
Incorrect
-
Where is the majority of Mg2+ absorbed?
Your Answer:
Correct Answer: Thick ascending limb of loop of Henle.
Explanation:Although the majority of the filtered magnesium is reabsorbed within the ascending loop of Henle, it is now recognized that the distal tubule also plays an important role in magnesium conservation.
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This question is part of the following fields:
- Medicine
- Renal
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Question 77
Incorrect
-
Question 78
Incorrect
-
A 55 year old female presents with progressive dyspnoea, dry cough and fever. She started methotrexate therapy six weeks ago. The current regimen includes methotrexate 15 mg/ week, folic acid 5 mg/day and aspirin 75 mg/day. There is no history of any other chronic illness. Vitals are as follows: Temp: 37.8C, pulse: 100 beats/min, BP: 110/80mmHg and SaO2: 90% on air. Examination reveals synovitis in both wrists, and metacarpophalangeal joints. On auscultation, there are scattered crepitations. Blood test reports are given below:Haemoglobin: 13.1g/dl (13.0 – 18.0 g/dL)WBC: 8.2 x109/l (4 – 11 x 109/l)Neutrophils: 5.1×109/l (1.5 – 7 x 109/l)Platelets: 280 x109/l (150 – 400 x 109/L)ESR: 48 mm/hr (0 – 30 mm/1st hr)Urea, electrolytes and creatinine: normalCXR: patchy airspace shadows bilaterallyWhat is the most likely diagnosis?
Your Answer:
Correct Answer: Methotrexate pneumonitis
Explanation:Pneumonitis is a serious and unpredictable side-effect of treatment with methotrexate (MTX) that may become life-threatening. The typical clinical symptoms include progressive shortness of breath and cough, often associated with fever. Hypoxaemia and tachypnoea are always present and crackles are frequently audible. Chest radiography reveals a diffuse interstitial or mixed interstitial and alveolar infiltrate, with a predilection for the lower lung fields. Pulmonary function tests show a restrictive pattern with diminished diffusion capacity. Lung biopsy reveals cellular interstitial infiltrates, granulomas or a diffuse alveolar damage pattern accompanied by perivascular inflammation. Most patients present in the first few months of starting methotrexate. It is important that all patients receiving methotrexate be educated concerning this potential adverse reaction and instructed to contact their physicians should significant new pulmonary symptoms develop while undergoing therapy. If methotrexate pneumonitis is suspected, methotrexate should be discontinued, supportive measures instituted and careful examination for different causes of respiratory distress conducted. This may be treated with corticosteroids once underlying infection has been excluded.
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This question is part of the following fields:
- Connective Tissue
- Medicine
-
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Question 79
Incorrect
-
Vitamin B12 is transported from the enterocytes to the bone marrow by which factor?
Your Answer:
Correct Answer: Transcobalamin II (TC IIi)
Explanation:B12 must be attached to IF for it to be efficiently absorbed, as receptors on the enterocytes in the terminal ileum of the small bowel only recognize the B12-IF complex. Once the IF/B12 complex is recognized by specialized ileal receptors, it is transported into the portal circulation. The vitamin is then transferred to transcobalamin II (TC-II/B12), which serves as the plasma transporter.
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This question is part of the following fields:
- Haematology
- Medicine
-
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Question 80
Incorrect
-
The most resistant area in the brain to hypoxia is:
Your Answer:
Correct Answer: Brain stem
Explanation:The structures in the brainstem are more resistant to hypoxia than the cerebral cortex and the rest of the brain structures.
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This question is part of the following fields:
- Cardiovascular
- Medicine
-
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Question 81
Incorrect
-
What is the average life span of neutrophils?
Your Answer:
Correct Answer: 24 hours
Explanation:The average lifespan of inactivated human neutrophils in the circulation has been reported by different approaches to be between 5 and 90 hours.
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This question is part of the following fields:
- Haematology
- Medicine
-
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Question 82
Incorrect
-
Which of the following is true of the Natriuretic hormones?
Your Answer:
Correct Answer: They are released in response to hypervolemia
Explanation:Natriuretic hormones are vasodilators released in response to hypervolemia.
Natriuretic hormones (NH) include three groups of compounds: the natriuretic peptides NPs (ANP, BNP and CNP), the gastrointestinal peptides (guanylin and uroguanylin), and endogenous cardiac steroids. These substances induce the kidney to excrete sodium and therefore participate in the regulation of sodium and water homeostasis, blood volume, and blood pressure (BP). In addition to their peripheral functions, these hormones act as neurotransmitters or neuromodulators in the brain.
Atrial natriuretic peptide (ANP) plays a crucial role in blood pressure regulation by inducing natriuresis and diuresis in the kidney, inhibiting renin secretion, aldosterone production, and promoting vasorelaxation. Two paracrine factors derived from endothelial cells play important roles in modulating ANP secretion. Endothelin, a potent vasoconstrictor, stimulates ANP secretion and augments stretch induced ANP secretion. The dramatic increase in ANP release produced by cardiac ischemia appears to be mediated in part by endothelin. Nitric oxide (NO), an important vasodilator, is also produced by endothelial cells and inhibits ANP secretion.
Brain natriuretic peptide (BNP) shares ANP’s receptor but is primarily associated with antifibrotic effects in ventricular remodeling, serving as a biomarker for heart failure and myocardial infarction.
C-type natriuretic peptide (CNP) acts locally in an autocrine/paracrine manner, exerting potent cardiovascular effects, including vasorelaxation and vascular remodeling post-injury. NPs also demonstrate diverse effects beyond cardiovascular and renal systems, such as bronchodilation, anti-inflammatory actions, and metabolic effects on adipose tissue and long bones.
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This question is part of the following fields:
- Cardiovascular
- Medicine
-
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Question 83
Incorrect
-
When during the cell cycle do the centrioles replicate?
Your Answer:
Correct Answer: G1 phase
Explanation:During G1 phase the cell will prepare for cell division. All the organelles will start to duplicate in this phase and the cell will begin to grow whilst proteins are also synthesized.
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This question is part of the following fields:
- Genetics
- Medicine
-
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Question 84
Incorrect
-
Pendrin is a Cl-/I- exchanger whose function is:
Your Answer:
Correct Answer: Transfer of iodide across the thyrocyte apical membrane into the colloid
Explanation:Pendrin is an anion transporter present in the inner ear, thyroid and kidney. It regulates the entrance of iodide from the thyroid cell to the colloid space. It has been proposed that its role could be the maintenance of the ionic composition of the endolymph.
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This question is part of the following fields:
- Endocrinology
- Medicine
-
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Question 85
Incorrect
-
An 18-year-old young lady is brought to the ER by her mother. She was found, lying on the floor having consumed an unidentified quantity of her mother's prescription pills with alcohol. The patient's mother is a known hypertensive under treatment. On examination, the patient was found to be lethargic, hypotensive with a BP of 70/50 mmHg, and bradycardic with a pulse rate of 38 bpm. A finger prick glucose is 3.2 mmol/L. Which TWO among the following are the most appropriate steps for the initial management of this patient?
Your Answer:
Correct Answer: Glucagon and isoprenaline
Explanation:The most appropriate steps of initial management include iv glucagon and iv isoprenaline.The most likely diagnosis in the above scenario (decreased conscious level, profound hypertension, and bradycardia) is β-blocker toxicity/overdose. Bronchospasm rarely occurs in an overdose of β-blockers, except where there is a history of asthma.Immediate management is to give iv glucagons (50–150μg/kg) followed by infusion to treat hypotension and isoprenaline or atropine to treat bradycardia. Where patients fail to respond to these measures, temporary pacing may be required. If the patient is seen within the first 4 hours of the overdose, gastric lavage may be of value.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 86
Incorrect
-
Which of the following is false with regard to the following statement: Proto- oncogenes can be transformed to oncogenes in the following ways.
Your Answer:
Correct Answer: Inhibition of P53
Explanation:Proto oncogenes cannot be transformed into oncogenes due to inhibition of P53 gene. There has to be a mutation in the proto oncogene. All the other options are true.
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This question is part of the following fields:
- Genetics
- Medicine
-
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Question 87
Incorrect
-
During quiet breathing the diaphragm’s role accounts for what percent of respiration?
Your Answer:
Correct Answer: 75%
Explanation:The contraction of the diaphragm accounts for approximately 75% of the air movement during normal breathing.
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This question is part of the following fields:
- Medicine
- Respiratory
-
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Question 88
Incorrect
-
From which of the following can niacin be synthesized in humans
Your Answer:
Correct Answer: Tryptophan
Explanation:Niacin, is also known as vitamin B3. The liver can synthesize niacin from the essential amino acid tryptophan, requiring 60 mg of tryptophan to make one mg of niacin.
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This question is part of the following fields:
- Haematology
- Medicine
-
-
Question 89
Incorrect
-
Around 30 patients have been admitted to the hospital following a suspected chemical attack in the city. The patients are extremely unwell, with symptoms of excessive salivation, lacrimation, diarrhoea, and emesis. Sarin gas was suspected as the most likely agent used in the attack. What is the mechanism of action of this chemical agent?
Your Answer:
Correct Answer: Inhibition of acetylcholinesterase
Explanation:Sarin acts by inhibiting acetylcholinesterase.Sarin gas is a highly toxic synthetic organophosphorus compound which causes inhibition of the enzyme acetylcholinesteraseSarin gas is a highly toxic synthetic organophosphorus compound which causes inhibition of the enzyme acetylcholinesterase. This results in high levels of acetylcholine (ACh).The effects of excessive ACh can be remembered by the mnemonic DUMBELLS:DiarrhoeaUrinationMiosis/muscle weaknessBronchorrhea/BradycardiaEmesisLacrimationSalivation/sweatingOrganophosphate insecticide poisoning:One of the effects of organophosphate poisoning is inhibition of acetylcholinesteraseFeatures can be predicted by the accumulation of acetylcholine (mnemonic = SLUD)SalivationLacrimationUrinationDefecation/diarrhoeacardiovascular: hypotension, bradycardiamiosis, muscle fasciculation.Organophosphate poisoning is treated with the anti-muscarinic atropine.
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This question is part of the following fields:
- Medicine
- Pharmacology
-
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Question 90
Incorrect
-
A 55-year-old diabetic male presents with a feeling of generally being unwell. He also has a history of atrial fibrillation and epilepsy. His main complaint is a blue tinge to his vision. Which one of his medications is most likely to be responsible?
Your Answer:
Correct Answer: Sildenafil
Explanation:Blue tinge of vision/cyanopsia is caused due to the intake of sildenafil citrate.Sildenafil citrate (Viagra) is the first oral drug to be widely approved for the treatment of erectile dysfunction. It is a potent and selective inhibitor of type-V phosphodiesterase, the primary form of the enzyme found in human penile erectile tissue, thereby preventing the breakdown of cyclic guanosine monophosphate (cGMP), the intracellular second messenger of nitric oxide.Uses:It is used for the treatment of erectile dysfunction, idiopathic pulmonary hypertension, premature ejaculation, high altitude illness, penile rehabilitation after radical prostatectomy, angina pectoris, and lower urinary tract symptoms.Adverse effects:Mild headache, flushing, dyspepsia, cyanopsia, back pain, and myalgias – due to a high concentration of PDE11 enzyme in skeletal muscle, which shows significant cross-reactivity with the use of tadalafil.It can also cause hypotension, dizziness, and rhinitis.Note: Xanthopsia (yellow-green vision) may occur secondary to treatment with digoxin.
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This question is part of the following fields:
- Medicine
- Pharmacology
-
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Question 91
Incorrect
-
All valves are closed in which phase of the cardiac cycle?
Your Answer:
Correct 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 92
Incorrect
-
The enzyme responsible for telomeres maintaining their length after cell division is called:
Your Answer:
Correct Answer: Telomerase
Explanation:Telomerase is the enzyme responsible for maintenance of the length of telomeres by addition of guanine-rich repetitive sequences. Telomerase activity is exhibited in gametes and stem and tumor cells.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 93
Incorrect
-
Choose the correct statement. The cells of the liver…
Your Answer:
Correct Answer: Help to maintain the normal blood glucose level.
Explanation:Synthesis of vitamin D3 takes place in both the liver and in the kidneys. The liver is responsible for an intermediate step and final synthesis takes place in the kidneys. Immunoglobulins are manufactured by plasma cells in respective organs where there is antigen exposure. The liver plays a major role in maintaining blood glucose levels by converting excess glucose to glycogen and converting glycogen back to glucose in time of need. Hepatocytes have enzymes that can deactivate steroid hormones.
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This question is part of the following fields:
- Hepatobiliary
- Medicine
-
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Question 94
Incorrect
-
Which of the following stimulate the release of aldosterone from the adrenal cortex?
Your Answer:
Correct Answer: Angiotensin 2
Explanation:Angiotensin II also stimulates the secretion of the hormone aldosterone from the adrenal cortex. Aldosterone causes the renal tubules to increase the reabsorption of sodium and water into the blood, while at the same time causing the excretion of potassium (to maintain electrolyte balance).
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This question is part of the following fields:
- Medicine
- Renal
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Question 95
Incorrect
-
Which of the following structures of the cardiac conduction system is located in the right posterior portion of the interatrial septum?
Your Answer:
Correct Answer: AV node
Explanation:AV node is located at the right posterior portion of the interatrial septum.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 96
Incorrect
-
Transport of Iron into enterocytes occurs via which membrane transporter?
Your Answer:
Correct Answer: Divalent metal transporter 1(dmt1)
Explanation:To be absorbed, dietary iron can be absorbed as part of a protein such as haem protein or iron must be in its ferrous Fe2+ form. A ferric reductase enzyme on the enterocytes’ brush border, duodenal cytochrome B (Dcytb), reduces ferric Fe3+ to Fe2+. A protein called divalent metal transporter 1 (DMT1), which can transport several divalent metals across the plasma membrane, then transports iron across the enterocyte’s cell membrane into the cell.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 97
Incorrect
-
A 78 year old woman presents to the clinic complaining of left sided temporal headaches and jaw claudication that has been going on for a month. A left temporal artery biopsy is negative. Results show:Hb: 130g/lPlatelets: 359*109/lWBC: 10*109/lCRP: 89mg/lWhich of the following options would be the next best step in the management of this patient?
Your Answer:
Correct Answer: Commence prednisolone
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 98
Incorrect
-
Tunica intima is made up of?
Your Answer:
Correct Answer: Endothelial cells
Explanation:Tunica intima is a single cell thick lining of endothelial cells that lines the inside of the blood vessels. It is the inner most layer of the blood vessel.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 99
Incorrect
-
An 81-year-old male presented to the emergency department following a fall at home. He was diagnosed with osteoporosis about five years ago. He presently complains of significant low back pain. A lumbar spine X-ray was suggestive of a fractured lumbar vertebra. A subsequent MRI scan of the lumbosacral spine revealed a new L3 burst fracture with no evidence of cord compression. A neurosurgical consult was sought and conservative management was planned accordingly in the form of pain control, physiotherapy, and mobilization (as allowed by the pain). He also has been diagnosed with chronic renal disease (stage IV) with a creatinine clearance of 21ml/min, he was started on a Buprenorphine patch. Which of the following opioids would be safest to use for his breakthrough pain?
Your Answer:
Correct Answer: Oxycodone
Explanation:Oxycodone is a safer opioid to use in patients with moderate to end-stage renal failure.Active metabolites of morphine accumulate in renal failure which means that long-term use is contraindicated in patients with moderate/severe renal failure. These toxic metabolites can accumulate causing toxicity and risk overdose. Oxycodone is mainly metabolised in the liver and thus safer to use in patients with moderate to end-stage renal failure with dose reductions.Adverse effects:Constipation is the most common overall side effect. Others include: asthenia, dizziness, dry mouth, headache, nausea, pruritus, etc. Medications in renal failure:Drugs to be avoided in patients with renal failureAntibiotics: tetracycline, nitrofurantoinNSAIDsLithiumMetforminDrugs that require dose adjustment:Most antibiotics including penicillin, cephalosporins, vancomycin, gentamicin, streptomycinDigoxin, atenololMethotrexateSulphonylureasFurosemideOpioidsRelatively safe drugs:Antibiotics: erythromycin, rifampicinDiazepamWarfarin
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This question is part of the following fields:
- Medicine
- Pharmacology
-
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Question 100
Incorrect
-
During which phase of the cell cycle does transcription of DNA synthesis molecules occur?
Your Answer:
Correct Answer: S
Explanation:DNA synthesis occurs in the S phase of the cell cycle. In the G1 phase the cell prepares to divide. In G2 the cellular organelles divide and in the M phase mitosis occur. In the G0 phase the cell becomes quiescent and does not divide further.
Interphase is composed of G1 phase (cell growth), followed by S phase (DNA synthesis), followed by G2 phase (cell growth). At the end of interphase comes the mitotic phase, which is made up of mitosis and cytokinesis and leads to the formation of two daughter cells.
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This question is part of the following fields:
- Genetics
- Medicine
-
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Question 101
Incorrect
-
What catalyses the conversion of adenosine to inosine?
Your Answer:
Correct Answer: Adenosine deaminase
Explanation:Adenosine deaminase (ADA) is an enzyme involved in purine metabolism. It is needed for the breakdown of adenosine from food and for the turnover of nucleic acids in tissues. ADA irreversibly deaminates adenosine, converting it to the related nucleoside inosine by the substitution of the amino group for a keto group.
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This question is part of the following fields:
- Medicine
- Metabolism
-
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Question 102
Incorrect
-
Which of the toxin secretion pathways in the cell membrane of gram– bacteria delivers the toxin extracellular in a 2 stage process to the host?
Your Answer:
Correct Answer: II
Explanation:Gram negative bacteria contain two membranes and there are about six specialized secretion systems. The secreted proteins play a key role in pathogenesis. Type II secretion systems (T2SS) are conserved in most Gram-negative bacteria, where they transport proteins from the periplasm into the extracellular environment. Because the T2SS channel is only found in the outer membrane, proteins secreted through this apparatus must first be delivered to the periplasm via the Sec or Tat secretion pathways and then to the extracellular environment making it a two-stage process.
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This question is part of the following fields:
- Infectious Diseases
- Medicine
-
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Question 103
Incorrect
-
A 26-year-old student has been brought to the emergency department in a confused state. His friends report that he has been complaining of headaches for the past few weeks. He has a low-grade fever and on examination is noted to have abnormally pink mucosa. What is the most likely diagnosis?
Your Answer:
Correct Answer: Carbon monoxide poisoning
Explanation:Confusion and pink mucosae are typical features of CO poisoning.The patient often presents, most commonly with headaches, and other symptoms like malaise, nausea, and dizziness.Carbon monoxide (CO) poisoning, considered as the great imitator of other diseases as the patients present with a myriad of symptoms. The carbon monoxide diffuses rapidly across the pulmonary capillary membrane binding to the haem molecule with a very high affinity (240 times that of oxygen) forming carboxy-haemoglobin (COHb). Non-smokers have a baseline COHb of ,3% while smokers have a baseline COHb of 10-15%.Features of carbon monoxide toxicity- Headache: 90% of cases- Nausea and vomiting: 50%- Vertigo: 50%- Confusion: 30%- Subjective weakness: 20%- Severe toxicity: ‘pink’ skin and mucosae, hyperpyrexia, arrhythmias, extrapyramidal features, coma, deathTreatment:Use of Hyperbaric oxygen therapy (HBOT) for treating mild to moderate CO poisoning is not routine.The selection criteria for HBOT in cases of CO poisoning include:• COHb levels > 20-25%• COHb levels > 20% in pregnant patient • Loss of consciousness• Severe metabolic acidosis (pH <7.1)• Evidence of end-organ ischemia (e.g., ECG changes, chest pain, or altered mental status)
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 104
Incorrect
-
A 22 year old man who has recently returned from a trip to Far East presents with sore eyes and symmetrical joint pain in his knees, ankles and feet. Labs reveal an elevated ESR. The synovial fluid aspirate is sterile and has a high neutrophil count. What is the most likely diagnosis?
Your Answer:
Correct Answer: Reactive arthropathy
Explanation:Reactive arthritis, (formerly known as Reiter’s syndrome), is an autoimmune condition that occurs after a bacterial infection of the gastrointestinal or urinary tract. It is categorized as a seronegative spondylarthritis because of its association with HLA-B27. Reactive arthritis primarily affects young men and usually presents with musculoskeletal or extra‑articular symptoms. The characteristic triad consists of arthritis, conjunctivitis, and urethritis. Symmetric lower limb arthropathy and a sterile joint aspirate points towards reactive arthropathy.
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This question is part of the following fields:
- Connective Tissue
- Medicine
-
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Question 105
Incorrect
-
Which one of the following is able to move across cell membranes by passive diffusion?
Your Answer:
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 106
Incorrect
-
The blood supply to the greater curvature of the stomach is via the:
Your Answer:
Correct Answer: Right and left gastro-epiploic arteries
Explanation:The blood supply to the greater curvature of the stomach is via the left and the right gastro-epiploic arteries branching from the splenic artery near the hilum.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
-
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Question 107
Incorrect
-
The process where by DNA fragments are separated by size and charge is called:
Your Answer:
Correct Answer: Gel electrophoresis
Explanation:Fragments of DNA of varying length can be separated on the basis of their charge and their size by a process called gel electrophoresis. Because DNA contains negatively charged phosphate groups, it will migrate in an electric field toward the positive electrode. Shorter chains migrate more rapidly through the pores of the gel, and thus separation depends on length. DNA bands in the gel can be visualized by various techniques including staining with dyes and autoradiography.
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This question is part of the following fields:
- Genetics
- Medicine
-
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Question 108
Incorrect
-
Major supplies of glycogen are found in ….
Your Answer:
Correct Answer: Liver and skeletal muscle
Explanation:The two major sites of glycogen storage are the liver and skeletal muscle. The concentration of glycogen is higher in the liver than in muscle however more glycogen is stored in skeletal muscle due to its greater mass.
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This question is part of the following fields:
- Medicine
- Metabolism
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Question 109
Incorrect
-
The spinothalamic tracts are particularly concerned with:
Your Answer:
Correct Answer: Pain and temperature sensations
Explanation:The spinothalamic tracts are part of the anterolateral system in the spinal cord and are responsible for transmitting sensory information related to pain, temperature, and crude touch from the peripheral nervous system to the thalamus in the brain. This sensory information is then relayed to the cerebral cortex for processing. The spinothalamic tracts are divided into two main pathways:
- Lateral spinothalamic tract: Transmits pain and temperature sensations.
- Anterior spinothalamic tract: Transmits crude touch and pressure sensations.
Control of posture: The reticulospinal and vestibulospinal tracts are primarily involved in the control of posture and balance. These tracts originate in the brainstem and help maintain posture by influencing the motor neurons that control axial and proximal muscles.
Voluntary skilled movements: The corticospinal tracts (also known as the pyramidal tracts) are responsible for voluntary skilled movements. These tracts originate in the motor cortex and descend through the brainstem and spinal cord to synapse on motor neurons that control fine motor movements, especially of the distal limbs.
Muscular tone: Muscular tone is primarily regulated by several tracts, including the reticulospinal and vestibulospinal tracts. Additionally, the rubrospinal tract (originating from the red nucleus in the midbrain) also contributes to motor control and muscle tone, particularly of the upper limbs.
Visual input: The optic tracts and pathways (including the optic nerve, optic chiasm, optic tract, lateral geniculate nucleus, and optic radiations) are responsible for transmitting visual information from the retina to the primary visual cortex in the occipital lobe. This pathway processes visual input, including aspects such as color, motion, and depth perception.
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This question is part of the following fields:
- Medicine
- Neurology
-
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Question 110
Incorrect
-
With regard to cell membrane proteins:
Your Answer:
Correct Answer: Carriers are involved in facilitated diffusion
Explanation:Pumps use a source of free energy such as ATP to transport ions against a gradient and is an example of active transport. Unlike channel proteins which only transport substances through membranes passively, carrier proteins can transport ions and molecules either passively through facilitated diffusion, or via secondary active transport. Channels are either in open state or closed state. When a channel is opened, it is open to both extracellular and intracellular. Pores are continuously open to both environments, because they do not undergo conformational changes. They are always open and active.
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This question is part of the following fields:
- Cell Biology
- Medicine
-
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Question 111
Incorrect
-
The branche(s) of the left coronary artery include:
Your Answer:
Correct Answer: Left circumflex artery & anterior interventricular artery
Explanation:The left main coronary divides into branches:
1. The left anterior descending artery branches off the left coronary artery and supplies blood to the front of the left side of the heart.
2. The circumflex artery branches off the left coronary artery and encircles the heart muscle.
The anterior interventricular artery is otherwise known as the anterior descending branch. The posterior descending artery comes from Right coronary artery.
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This question is part of the following fields:
- Cardiovascular
- Medicine
-
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Question 112
Incorrect
-
Which one of the following is most likely to be seen in a patient with multiple endocrine neoplasia (MEN) type I?
Your Answer:
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 113
Incorrect
-
Choose the most correct missing words to complete the statement: A portion of circulating growth hormone is bound to the ____ receptor and activates the ____ pathway that mediates its effect.
Your Answer:
Correct Answer: Growth hormone receptor (extracellular domain), jak 2stat
Explanation:The growth hormone receptor is a transmembrane protein involved in the STATs, MAPK and PI3-kinase/Akt pathways. The JAK-STAT signalling pathway is activated by different ligands, such as growth hormone, interferon and interleukin. This pathway is involved in the expression of genes associated with oncogenesis, immunity, proliferation, differentiation and apoptosis. Errors in these pathways can produce leukaemia’s and other myeloproliferative disorders.
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This question is part of the following fields:
- Endocrinology
- Medicine
-
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Question 114
Incorrect
-
Which of the following drugs requires plasma level monitoring?
Your Answer:
Correct Answer: Vancomycin
Explanation:All patients require plasma-vancomycin measurement (after 3 or 4 doses if renal function normal, earlier if renal impairment). There is a risk of nephrotoxicity including renal failure, interstitial nephritis and ototoxicity.
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This question is part of the following fields:
- Medicine
- Pharmacology
-
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Question 115
Incorrect
-
During which phase of meiosis does exchange of genetic material occur accounting for genetic diversity between individuals:
Your Answer:
Correct 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 116
Incorrect
-
Drug-induced lupus erythematosus most often occurs after taking which of the following drugs?
Your Answer:
Correct Answer: Procainamide
Explanation:Many drugs are responsible for causing drug induced lupus. However, it is most commonly associated with hydralazine, procainamide and quinidine.
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This question is part of the following fields:
- Connective Tissue
- Medicine
-
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Question 117
Incorrect
-
Which of the following structures is not part of the conducting system of the heart?
Your Answer:
Correct Answer: Ventricular wall
Explanation:The conduction system of the heart consists of the SA node, AV node, internodal pathway between these two nodes, Bundle of His and the purkinje fibers
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This question is part of the following fields:
- Cardiovascular
- Medicine
-
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Question 118
Incorrect
-
A 22 year old nulliparous female presents with shortness of breath. She has a history of recurrent deep vein thrombosis. Complete blood count and clotting screen reveals the following results:Hb: 12.4 g/dl Plt: 137 WBC: 7.5*109/l PT: 14 secs APTT: 46 secs Which of the following would be the most likely diagnosis?
Your Answer:
Correct Answer: Antiphospholipid syndrome
Explanation:The combination of APTT and low platelets with recurrent DVTs make antiphospholipid syndrome the most likely diagnosis.
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This question is part of the following fields:
- Connective Tissue
- Medicine
-
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Question 119
Incorrect
-
G cells release which of the following substances
Your Answer:
Correct Answer: Gastrin
Explanation:The G cell is a type of cell in the stomach and duodenum that secretes gastrin. It works in conjunction with gastric chief cells and parietal cells. G cells are found deep within the pyloric glands of the stomach antrum, and occasionally in the pancreas and duodenum. Gastrin-releasing peptide, as well as the presence of amino acids in the stomach, stimulates the release of gastrin from the G cells. Gastrin stimulates enterochromaffin-like cells to secrete histamine. Gastrin also targets parietal cells by increasing the amount of histamine and the direct stimulation by gastrin, causing the parietal cells to increase HCl secretion in the stomach.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
-
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Question 120
Incorrect
-
Which of the following is an incorrect statement regarding the structure of DNA?
Your Answer:
Correct Answer: The two strands of DNA are held together by cysteine bonds.
Explanation:The two strands of DNA are held together by hydrogen bonds formed between the nucleotide bases.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 121
Incorrect
-
Which are the main hormones secreted by the posterior pituitary gland.
Your Answer:
Correct Answer: Oxytocin and vasopressin
Explanation:The posterior pituitary gland secretes oxytocin and vasopressin (antidiuretic hormone). These hormones are stored in Herring bodies before being secreted into the bloodstream.
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This question is part of the following fields:
- Endocrinology
- Medicine
-
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Question 122
Incorrect
-
Which enzyme deficiency can lead to ammonia intoxication?
Your Answer:
Correct Answer: Ornithine transcarbamylase
Explanation:Ornithine transcarbamylase deficiency also known as OTC deficiency is the most common urea cycle disorder in humans. Ornithine transcarbamylase, the defective enzyme in this disorder is the final enzyme in the proximal portion of the urea cycle, responsible for converting carbamoyl phosphate and ornithine into citrulline. OTC deficiency is inherited in an X-linked recessive manner, meaning males are more commonly affected than females.
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This question is part of the following fields:
- Medicine
- Metabolism
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Question 123
Incorrect
-
The liver is the principal site for?
Your Answer:
Correct Answer: Storage of iron
Explanation:The liver mainly synthesizes proteins including albumin, globulins and coalgulative factors. Vitamin B12 is taken in via the diet and stored by the liver. Vitamin C is not stored and excessive vitamin C is excreted via urine. Liver is the main site of iron storage, where it is stored in the form of ferritin.
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This question is part of the following fields:
- Hepatobiliary
- Medicine
-
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Question 124
Incorrect
-
Which of the following components regulate cardiac output?
Your Answer:
Correct Answer: All of the above
Explanation:Cardiac output is regulated by the autonomic nervous system with sympathetic nerves having a positive chronotropic and inotropic effect and parasympathetic nerves having the opposite effect. An increase in preload will increase cardiac output likewise an afterload increase will also increase cardiac output.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 125
Incorrect
-
The Wiebel-Palade body found in the endothelial cells is responsible for the production and release of which factor?
Your Answer:
Correct Answer: Von Willebrand factor
Explanation:Weibel-Palade bodies are the storage granules of endothelial cells, the cells that form the inner lining of the blood vessels and heart. They store and release two principal molecules, von Willebrand factor and P-selectin, and thus play a dual role in haemostasis and inflammation.
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This question is part of the following fields:
- Cardiovascular
- Medicine
-
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Question 126
Incorrect
-
Where would one normally find venous valves?
Your Answer:
Correct Answer: Saphenous vein
Explanation:The intima of the limb veins is folded at intervals to form venous valves that prevent retrograde flow. There are no valves present in the very small veins, the great veins, or the veins in the brain and viscera.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 127
Incorrect
-
Which of the following groups are purines?
Your Answer:
Correct Answer: Adenine, guanine, hypoxanthine
Explanation:There are many naturally occurring purines. They include the nucleobases, adenine and guanine. Other notable purines are hypoxanthine, xanthine), theobromine, caffeine, uric acid and isoguanine.
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This question is part of the following fields:
- Medicine
- Metabolism
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Question 128
Incorrect
-
The alpha amylases hydrolyse which linkages in the ingested polysaccharides?
Your Answer:
Correct Answer: 1:4α linkages
Explanation:Alfa amylase hydrolyses the α (1-4) glyosidic bonds in amylose and amylopectin and leave primarily maltose.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 129
Incorrect
-
In response to tissue injury, which of these cannot sensitize and activate nociceptors?
Your Answer:
Correct Answer: Calcium
Explanation:Histamine, serotonin, bradykinin and prostaglandin are all chemical mediators of inflammation with different distinct functions however all activate nociceptors. Calcium on the other hand cannot sensitize or activate nociceptors.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 130
Incorrect
-
A 22 year old man is being evaluated for chronic lower backache. Which of the following would most strongly point towards the diagnosis of ankylosing spondylitis?
Your Answer:
Correct Answer: Reduced lateral flexion of the lumbar spine
Explanation:Ankylosing spondylitis (spondylarthritis) is a chronic inflammatory disease of the axial skeleton that leads to partial or even complete fusion and rigidity of the spine. Males are disproportionately affected and upwards of 90% of patients are positive for the HLA-B27 genotype, which predisposes to the disease. The most characteristic early finding is pain and stiffness in the neck and lower back, caused by inflammation of the vertebral column and the sacroiliac joints. The pain typically improves with activity and is especially prominent at night. Other articular findings include tenderness to percussion and displacement of the sacroiliac joints (Mennell’s sign), as well as limited spine mobility, which can progress to restrictive pulmonary disease. The most common extra-articular manifestation is acute, unilateral anterior uveitis. Diagnosis is primarily based on symptoms and x-ray of the sacroiliac joints, with HLA-B27 testing and MRI reserved for inconclusive cases. There is no curative treatment, but regular physiotherapy can slow progression of the disease. Additionally, NSAIDs and/or tumour necrosis factor-α inhibitors may improve symptoms. In severe cases, surgery may be considered to improve quality of life. The spine adopts a bamboo shape, not lordosis. The pain usually improves as the day progresses. leg raise test causes pain in cases of meningitis etc not in this case.
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This question is part of the following fields:
- Connective Tissue
- Medicine
-
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Question 131
Incorrect
-
Which of the following is correctly paired?
Your Answer:
Correct Answer: F cells : pancreatic polypeptide
Explanation:Pancreatic polypeptide is secreted by F-cells, which represent the smallest proportion of islet cells in the pancreas. These cells establish the embryological origin of the pancreas. Pancreatic polypeptide regulates endocrine and exocrine activities by the pancreas.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 132
Incorrect
-
A 23 year old male presents with a history of lower back pain for the last one year. Presence of which of the following features most likely points towards ankylosing spondylitis?
Your Answer:
Correct Answer: Bilateral erosion of sacroiliac joints on X-ray
Explanation:Bilateral erosions of the sacroiliac joints on pelvic radiographs of patients with ankylosing spondylitis are an important feature of the modified New York classification criteria. Although HLA-B27 is commonly associated with AS, it can also be found in normal individuals. Back stiffness is worse in the morning and gets better as the day progresses. Tenderness and limited lumbar motion can be associated with other spine problems as well and is not characteristic of rheumatoid arthritis.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 133
Incorrect
-
A 27-year-old female diagnosed with rheumatoid arthritis has failed to respond to methotrexate and sulfasalazine. Her GP decides to start her on etanercept injections. Which one among the following is an adverse effect associated with the use of etanercept?
Your Answer:
Correct Answer: Reactivation of tuberculosis
Explanation:Among the give options, reactivation of tuberculosis may occur in a patient under treatment with etanercept.Etanercept is a biological TNF inhibit commonly used to control ankylosing spondylitis, juvenile idiopathic arthritis, plaque psoriasis, psoriatic arthritis, and rheumatoid arthritis.Etanercept is a soluble receptor that binds both TNF-alpha and TNF-beta to inhibit the inflammatory response in joints and skin that is characteristic of these autoimmune disorders.The most common adverse effects include infections (viral, bacterial, and fungal – mostly upper respiratory tract infections) and injection site reaction (erythema, itching, pain, swelling, bleeding, bruising).Rarely it can also cause, reactivation of hepatitis B and TB, pneumocystis pneumonia, congestive cardiac failure, Steven-Johnson syndrome, toxic epidermal necrolysis, etc.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 134
Incorrect
-
During strenuous exercise the following arterial change can take place in a fit athlete:
Your Answer:
Correct Answer: No change takes place
Explanation:The changes which occur in arterial pH, PO2 and PCO2 values during exercise are usually small. Arterial PO2 often rises slightly because of hyperventilation although it may eventually fall at high work rates. During vigorous exercise, when sufficient oxygen for flux through the Krebs cycle is not available, the increased reliance on glycolysis results in increased accumulation of lactic acid, which initially leads to an increase in PaCO2 . However, this is counteracted by the stimulation of ventilation and as a result PaCO2 is decreased. This provides some respiratory compensation for further lactic acid production and prevents a decline in blood pH, which remains nearly constant during moderate exercise.
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This question is part of the following fields:
- Medicine
- Respiratory
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Question 135
Incorrect
-
Question 136
Incorrect
-
An exaggerated response to a noxious stimulus is called:
Your Answer:
Correct Answer: Hyperalgesia
Explanation:Allodynia is the sensation of pain following non-painful stimulation.
Hyperalgesia is enhanced intensity of pain sensation.
Causalgia is a constant burning pain resulting from peripheral nerve injury.
Hyperesthesia is the abnormal increase in sensitivity to stimuli of sense.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 137
Incorrect
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A 30-year-old female was brought to the ER in a confused state. The patient works in a photograph development laboratory. On admission, she was hypoxic and hypotensive. A provisional diagnosis of cyanide poisoning was made. What is the definitive treatment?
Your Answer:
Correct Answer: Hydroxocobalamin
Explanation:Cyanide poisoning: Aetiology:Smoke inhalation, suicidal ingestion, and industrial exposure (specific industrial processes involving cyanide include metal cleaning, reclaiming, or hardening; fumigation; electroplating; and photo processing) are the most frequent sources of cyanide poisoning. Treatment with sodium nitroprusside or long-term consumption of cyanide-containing foods is a possible source.Cyanide exposure most often occurs via inhalation or ingestion, but liquid cyanide can be absorbed through the skin or eyes. Once absorbed, cyanide enters the blood stream and is distributed rapidly to all organs and tissues in the body. Pathophysiology:Inside cells, cyanide attaches itself to ubiquitous metalloenzymes, rendering them inactive. Its principal toxicity results from inactivation of cytochrome oxidase (at cytochrome a3), thus uncoupling mitochondrial oxidative phosphorylation and inhibiting cellular respiration, even in the presence of adequate oxygen stores.Presentation:• ‘Classical’ features: brick-red skin, smell of bitter almonds• Acute: hypoxia, hypotension, headache, confusion• Chronic: ataxia, peripheral neuropathy, dermatitisManagement:• Supportive measures: 100% oxygen, ventilatory assistance in the form of intubation if required.• Definitive: Hydroxocobalamin (iv) is considered the drug of choice and is approved by the FDA for treating known or suspected cyanide poisoning. • Coadministration of sodium thiosulfate (through a separate line or sequentially) has been suggested to have a synergistic effect on detoxification.Mechanism of action of hydroxocobalamin: • Hydroxocobalamin combines with cyanide to form cyanocobalamin (vitamin B-12), which is renally cleared.• Alternatively, cyanocobalamin may dissociate from cyanide at a slow enough rate to allow for cyanide detoxification by the mitochondrial enzyme rhodanese.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 138
Incorrect
-
What is the primary cause of ketoacidosis in Type 1 diabetes?
Your Answer:
Correct Answer: Lipolysis
Explanation:in type 1 diabetics the lack of insulin in the bloodstream prevents glucose absorption, thereby inhibiting the production of oxaloacetate (a crucial precursor to the β-oxidation of fatty acids) through reduced levels of pyruvate (a by-product of glycolysis), and can cause unchecked ketone body production (through fatty acid metabolism or lipolysis) potentially leading to dangerous glucose and ketone levels in the blood.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 139
Incorrect
-
Concerning surface anatomy, where is the mitral valve found?
Your Answer:
Correct Answer: Situated in the 4th intercostal space to the left of the sternum
Explanation:The mitral valve is situated in the left 4th intercostal space just beneath the sternum.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 140
Incorrect
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Question 141
Incorrect
-
A 24-year-old women presents following an overdose. Which one of the following would suggest anticholinergic syndrome?
Your Answer:
Correct Answer: Mydriasis occurs
Explanation:Anticholinergic syndrome results from the inhibition of muscarinic cholinergic neurotransmission. Clinical manifestations can be remembered by the mnemonic, red as a beet, dry as a bone, blind as a bat, mad as a hatter, hot as a hare, and full as a flask. The mnemonic refers to the symptoms of flushing, dry skin and mucous membranes, mydriasis (dilated pupil) with loss of accommodation, altered mental status, fever, and urinary retention, respectively.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 142
Incorrect
-
Which of the following cells are attracted to the surface of endothelium by selectins?
Your Answer:
Correct Answer: Neutrophils
Explanation:Selectins are expressed on the surface of the endothelium. P selectins are released from weibel-palade bodies and E selectins are induced by cytokines (TNF and IL-1). They bind to receptors on the neutrophils called saiyl lewis X.
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This question is part of the following fields:
- Immunology
- Medicine
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Question 143
Incorrect
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Question 144
Incorrect
-
An 82 year old man arrives at the clinic with painful right upper arm that he has been experiencing for the last few months. The pain is gradually worsening and often wakes him up at night. He is a known case of Paget's disease involving his lumbar spine and pelvis and is currently taking oral bisphosphonates. On examination, shoulder movements are intact. Which of the following is the most likely cause of his arm pain?
Your Answer:
Correct Answer: Osteosarcoma
Explanation:Paget’s accelerates the remodelling process with old bone breaking down more quickly which disrupts the normal growth process. New bone development eventually adjusts to the faster pace and speeds up on its own. The pace is too fast for healthy bone growth, and the regrowth ends up softer and weaker than normal. The effect of this accelerated process causes bone pain, fractures, and deformities. Since osteosarcoma is a type of bone cancer linked to abnormal bone growth, this makes it a rare but possible complication of Paget’s disease although the chances of developing osteosarcoma are minimal. Fractures are painful and restrict movement whereas this patients pain is gradually developing. Pain associated with osteoarthritis is usually mild to moderate and worsens as the day progresses.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 145
Incorrect
-
Which of the following stimuli increase growth hormone secretion?
Your Answer:
Correct 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 146
Incorrect
-
An 82 year old male woke up experiencing incoherent speech - he is also finding it difficult to find the right words to explain his thoughts. Doctors have examined him, and everything else appears to be normal. They have also found that his comprehension is good. From the list of options, choose the anatomical site which in this instance, is most likely affected.
Your Answer:
Correct Answer: Broca’s Area
Explanation:The combination of good comprehension but poor speech quality in this patient is consistent with damage to the Broca’s area. The Wernicke’s area is responsible for the understanding of speech, and so is not consistent with this patient.
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This question is part of the following fields:
- Geriatrics
- Medicine
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Question 147
Incorrect
-
In liver failure there is likely to be?
Your Answer:
Correct Answer: Bleeding disorders
Explanation:Liver failure can lead to several significant changes in the body’s physiology, but let’s review each option in the context of liver failure:
- Raised blood urea: This is not typical of liver failure. In liver failure, blood urea nitrogen (BUN) levels are often low because the liver is not effectively converting ammonia to urea.
- Increase in the albumin/globulin ratio in the blood: This is incorrect. In liver failure, albumin production decreases, leading to a lower albumin/globulin ratio.
- Bleeding disorders: This is possible, but it often fluctuates. Liver failure can lead to both bleeding tendencies due to decreased production of clotting factors and a hypercoagulable state due to the reduced synthesis of anticoagulant proteins like Protein C and S.
- Stable blood glucose level: This is incorrect. Liver failure often causes hypoglycemia because the liver’s ability to produce glucose via gluconeogenesis and glycogenolysis is impaired.
- Increased absorption of fat: This is incorrect. Liver failure can lead to decreased bile production, which is necessary for fat emulsification and absorption, resulting in decreased fat absorption.
Given these points, the most likely option related to liver failure would actually be issues related to bleeding complications.
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This question is part of the following fields:
- Hepatobiliary
- Medicine
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Question 148
Incorrect
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A 25-year-old female presents to the emergency department with severe breathlessness and tinnitus. She is under treatment for asthma and depression with albuterol and amitriptyline respectively.On examination, she seems agitated with a BP of 100/44, a pulse rate of 112 bpm, a respiratory rate of 30 cycles/min, and a temperature of 37.8'C.An arterial blood gas performed reveals:pH: 7.48 (7.36 – 7.44)pO2: 11.2 kPa (11.3 – 12.6 kPa)pCO2: 1.9 kPa (4.7 – 6.0 kPa)Bicarbonate: 13 mmol/l (20 – 28 mmol/L)What is the most probable diagnosis?
Your Answer:
Correct Answer: Salicylate poisoning
Explanation:The blood gas analysis provided above is suggestive of a mixed respiratory alkalosis and metabolic acidosis characteristic of salicylate overdose.Pathophysiology:The direct stimulation of the cerebral medulla causes hyperventilation and respiratory alkalosis.As it is metabolized, it causes an uncoupling of oxidative phosphorylation in the mitochondria. Lactate levels then increase due to the increase in anaerobic metabolism. This, along with a slight contribution from the salicylate metabolites result in metabolic acidosis.Tinnitus is characteristic and salicylate ototoxicity may produce deafness. Other neurological sequelae include encephalopathy and agitation, seizures and CNS depression and coma. Cardiovascular complications include tachycardia, hypotension, and dysrhythmias (VT, VF, and asystole).
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 149
Incorrect
-
Lipid- lowering drugs like Lovastatin reduce cholesterol synthesis by inhibiting which enzyme?
Your Answer:
Correct Answer: HMG-CoA reductase
Explanation:Statins, also known as HMG-CoA reductase inhibitors, are a class of lipid-lowering medications. Statins have been found to reduce cardiovascular disease (CVD) and mortality in those who are at high risk.
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This question is part of the following fields:
- Medicine
- Metabolism
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Question 150
Incorrect
-
When oxygen supply is restored, lactate formed during anaerobic metabolism is converted back to?
Your Answer:
Correct Answer: Pyruvate
Explanation:During intense exercise, when the rate of demand for energy is high, glucose is broken down and oxidized to pyruvate, and lactate is then produced from the pyruvate faster than the body can process it, causing lactate concentrations to rise. The resulting lactate can be used in two ways:1. Oxidation back to pyruvate by well-oxygenated muscle cells, heart cells, and brain cells. Pyruvate is then directly used to fuel the Krebs cycle2. Conversion to glucose via gluconeogenesis in the liver and release back into circulation.
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This question is part of the following fields:
- Medicine
- Metabolism
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Question 151
Incorrect
-
Carotid bodies...
Your Answer:
Correct Answer: Are located near the bifurcation of the carotid arteries bilaterally
Explanation:The carotid body is a small cluster of chemoreceptors and supporting cells located near the fork (bifurcation) of the carotid artery (which runs along both sides of the throat).The carotid body detects changes in the composition of arterial blood flowing through it, mainly the partial pressure of oxygen, but also of carbon dioxide. Furthermore, it is also sensitive to changes in pH and temperature. Carotid bodies trigger an action potential through the afferent fibers of the glossopharyngeal nerve,
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This question is part of the following fields:
- Medicine
- Respiratory
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Question 152
Incorrect
-
A 62 year old female has complained she feels unsteady when she is walking. She is examined and is found to have pyramidal weakness of her left lower leg. She also has reduced pain and temperature sensation on her right leg and right side of her torso up to the umbilicus. Her joint position sense is also impaired in her left big toe but is found to be normal elsewhere. She has definite left extensor plantar response, and the right plantar response is equivocal. Where is the lesion?
Your Answer:
Correct Answer: Left mid-thoracic cord
Explanation:In Brown-Sequard syndrome, there is paralysis and loss of proprioception, which occurs on the same (ipsilateral) side of the body, as the lesion. Loss of pain and temperature sensation, therefore, occurs on the opposite (contralateral) side of the body as the lesion.
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This question is part of the following fields:
- Geriatrics
- Medicine
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Question 153
Incorrect
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Question 154
Incorrect
-
What are the diagnostic criteria for an ST segment elevation type of acute myocardial infarction?
Your Answer:
Correct Answer: 1 mm ST elevation in 2 limb leads
Explanation:The current guidelines for the ECG diagnosis of the ST segment elevation type of acute myocardial infarction require at least 1 mm (0.1 mV) of ST segment elevation in the limb leads, and at least 2 mm elevation in the precordial leads. These elevations must be present in anatomically contiguous leads. (I, aVL, V5, V6 correspond to the lateral wall; V3-V4 correspond to the anterior wall ; V1-V2 correspond to the septal wall; II, III, aVF correspond to the inferior wall.)
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 155
Incorrect
-
Which of the following conditions is procoagulant?
Your Answer:
Correct Answer: Factor V Leiden
Explanation:Factor V Leiden is a genetic mutation of one of the clotting factors in the blood, Factor V. This mutation makes Factor V resistant to inactivation by activated Protein C, which normally helps to regulate clot formation. As a result, individuals with Factor V Leiden are at increased risk of developing abnormal blood clots (thrombophilia), making it a procoagulant condition.
The other conditions listed are associated with bleeding tendencies rather than increased clotting:
- Afibrinogenemia: A rare genetic disorder where there is a complete lack of fibrinogen, leading to bleeding problems.
- Hemophilia: A group of inherited bleeding disorders where blood does not clot properly due to the lack of sufficient blood-clotting proteins (factors VIII or IX).
- Hypothrombinemia: A condition characterized by low levels of prothrombin, leading to increased bleeding.
- Christmas disease (Hemophilia B): A form of hemophilia caused by a deficiency of factor IX, resulting in a bleeding tendency.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 156
Incorrect
-
Where is the aqueous humor normally reabsorbed?
Your Answer:
Correct Answer: Canal of schlemm
Explanation:Aqueous humor is a clear protein free fluid secreted by the ciliary body, it travels to the anterior chamber through the pupil and is absorbed through a network of trabeculae into the canal of schlemm
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This question is part of the following fields:
- Medicine
- Neurology
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Question 157
Incorrect
-
Which among the following antihypertensives is centrally acting?
Your Answer:
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 158
Incorrect
-
What type of intercellular connection found between cardiac muscle fibers allow for the spread of excitation from one cell to another?
Your Answer:
Correct Answer: Gap junctions
Explanation:The cardiac muscles have gap junctions in-between the cells. They form 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 159
Incorrect
-
A 36 year old man arrives at the clinic complaining of pain and swelling of the left knee, ankles and right hallux. He has acute conjunctivitis, and dysuria. He suffered from an episode of gastroenteritis two weeks back. Clinical examination shows left Achilles tendonitis and right plantar fasciitis. Radiological examination reveals left sacroiliitis, with evidence of enthesitis, joint erosions and periostitis. HLA-B27 is positive. Which of the following is the most likely diagnosis?
Your Answer:
Correct Answer: Reiter’s syndrome
Explanation:Reactive arthritis, (formerly known as Reiter’s syndrome), is an autoimmune condition that occurs after a bacterial infection of the gastrointestinal or urinary tract. It is categorized as a seronegative spondylarthritis because of its association with HLA-B27. Reactive arthritis primarily affects young men and usually presents with musculoskeletal or extra‑articular symptoms. The characteristic triad consists of arthritis, conjunctivitis, and urethritis. The diagnosis is based on clinical features such as patient history and physical examination; there are no specific tests for reactive arthritis. Treatment is primarily symptomatic and consists of the administration of NSAIDs, as most patients recover spontaneously. extraarticular dermatologic manifestations include skin lesions of the glans resembling psoriasis (balanitis circinata); hyperkeratinisation of the palms and soles (keratoderma blenorrhagicum), oral ulcers.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 160
Incorrect
-
A 30-year-old female presented with upper abdominal pain. She was diagnosed with an unknown coagulopathy and has a previous history of stroke. She has been on warfarin therapy for the past 4 months. Her international normalised ratio (INR) was stabilised between 2.5 and 3.0. Noticing abnormal coagulation results, her surgeon has requested a medical consult.Her blood investigations revealed:White cell count: 13 × 109/lHaemoglobin (Hb): 11 g/dlActivated partial thromboplastin time (APTT): NormalPlatelets: 140 × 109/lINR: 6.0Pancreatic enzymes and liver function tests were normal.Other investigations:An ultrasound of the abdomen was normal.An upper GI endoscopy revealed mild gastritis. What is the most appropriate step to be taken regarding warfarin therapy?
Your Answer:
Correct Answer: Stop warfarin and observe
Explanation:The most appropriate treatment in this patient would be to stop warfarin therapy and keep the patient under observation.The drugs that lead to enhanced potency of warfarin include: disulfiram, trimethoprim-sulphamethoxazole, metronidazole, phenylbutazone, aspirin, heparin, and clofibrate. Liver disease, thrombocytopenia, hyperthyroidism also increase the oral anticoagulant potency.If the patient has minor bleeding and the international normalized ratio (INR) is >6.0, warfarin should be stopped; the INR should be rechecked daily and in addition to the stoppage of warfarin, vitamin K 2.5 mg oral or 0.5 mg intravenously should also be administered.In a patient with INR of 2.0 or 3.0, it takes two or three times longer for that individual’s blood to clot than someone who is not taking any anticoagulants. Most patients on warfarin have an INR goal of 2 to 3.If there is major bleeding then prothrombin complex concentrates 50 u/kg or fresh-frozen plasma 15 ml/kg may be considered.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 161
Incorrect
-
Which of the following forms the language areas of the cerebral cortex?
Your Answer:
Correct Answer: All of the above
Explanation:Broca’s area, Wernicke’s area, the submarginal sulcus and the angular gyrus all form the language areas of the cerebral cortex.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 162
Incorrect
-
Which of the following prevents auto-digestion of the stomach by gastric secretions:
Your Answer:
Correct Answer: Trefoil peptides and mucus- bicarbonate layer.
Explanation:Pepsinogen is the inactive form of pepsin, a protein digesting enzyme. Bombesin is a peptide which stimulates gastrin secreting cells in the stomach increasing production of gastric acid. Ecl or enterochromaffin cells are neuroendocrine cells that aid in the production of gastric acid via the release of histamine. Oxyntic cells are also known as parietal cells and are the main cells secreting gastric hydrochloric acid (HCl). Gastric acid and pepsin are harmful agents for the gastric mucosa and can result in autodigestion. It is therefore protected by several agents including bicarbonate which neutralizes the acidity of gastric acid while Trefoil peptides are a component of gastric mucosa that form a gel like layer in the gastric epithelium protecting it from harmful agents.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 163
Incorrect
-
Which of the following with regard to DNA mutations does not fit:
Your Answer:
Correct Answer: All gene mutations cause clinical disease entities
Explanation:All gene mutations do not cause a clinical manifestation of the disease, some gene mutations are silent mutations. They are present but do not cause any disease.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 164
Incorrect
-
A patient with achalasia
Your Answer:
Correct Answer: Has decreased production of vasoactive intestinal polypeptide (VIP)
Explanation:Oesophageal achalasia is an oesophageal motility disorder involving the smooth muscle layer of the oesophagus and the lower oesophageal sphincter (LES). It is characterized by incomplete LES relaxation, increased LES tone, and lack of peristalsis of the oesophagus (inability of smooth muscle to move food down the oesophagus) in the absence of other explanations like cancer or fibrosis. In achalasia, there is loss of nitric oxide (NO) and vasoactive intestinal polypeptide (VIP) releasing inhibitory neurons.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 165
Incorrect
-
The small opening in the cochlea through which the upper scala vestibuli and lower scala tympani communicates is called the:
Your Answer:
Correct Answer: Helicotrema
Explanation:The helicotrema is the part of cochlear labyrinth where the scala tympani and the scala vestibuli meet.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 166
Incorrect
-
Cross-bridges between actin and myosin filaments contain:
Your Answer:
Correct Answer: Calcium ions
Explanation:At rest troponin I is bound to actin and tropomyosin and covers the site where the myosin head interacts with actin. When calcium enters into the muscle, it binds with troponin C and causes a structural change in troponin I which moves out of the myosin binding site and causes the cross bridges between the actin and myosin filaments to occur.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 167
Incorrect
-
In the presence of oxygen , lactate that was produced under anaerobic conditions is converted to:
Your Answer:
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
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Question 168
Incorrect
-
The energy needed for glycogen synthesis comes from which compound?
Your Answer:
Correct Answer: UTP
Explanation:Glycogen synthesis is, unlike its breakdown, endergonic—it requires the input of energy. Energy for glycogen synthesis comes from uridine triphosphate (UTP)
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This question is part of the following fields:
- Medicine
- Metabolism
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Question 169
Incorrect
-
Which of the following drugs have the best gram positive cover?
Your Answer:
Correct Answer: Glycopeptides
Explanation:Cephalosporin has a mixed coverage of gram positive and negative organisms. Aminoglycosides are active against gram negative aerobic bacteria. Quinolones mainly cover gram negative bacteria. Monobactams primarily cover infections caused by gram negative bacteria. Glycopeptides are antibiotics effective primarily against gram positive cocci.
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This question is part of the following fields:
- Infectious Diseases
- Medicine
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Question 170
Incorrect
-
The ATPase of parietal cells moves:
Your Answer:
Correct Answer: H+ into the gastric lumen in exchange for a k+
Explanation:ATPase of the parietal cell is also known as the proton pump, which moves H+ ions into the gastric lumen in exchange for K+ ions into the cell.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 171
Incorrect
-
A 20-year-old male presents to the emergency department about 4 hours after ingesting 20g of paracetamol. N-acetyl cysteine was started immediately. What is the mechanism of action of N-acetyl cysteine?
Your Answer:
Correct Answer: Replenishes glutathione
Explanation:N-acetylcysteine depletes glutathione reserves by providing cysteine, which is an essential precursor in glutathione production.Glutathione within the liver can normally detoxify these minuscule quantities of NAPQI and prevent tissue damage.N-acetylcysteine (NAC) is the mainstay of therapy for acetaminophen toxicity.Paracetamol overdose:The liver normally conjugates paracetamol with glucuronic acid/sulphate. During an overdose, the conjugation system becomes saturated leading to oxidation by cytochrome P450 (predominately CYP2E1) mixed-function oxidases. This produces a toxic metabolite N-acetyl-p-benzoquinone imine (NAPQI).Normally glutathione acts as a defence mechanism by conjugating with the toxin forming the non-toxic mercapturic acid. If glutathione stores run-out, the toxin forms covalent bonds with cell proteins, denaturing them and leading to cell death.Other uses: In COPD, cystic fibrosis, and other lung conditions, nebulized NAC has mucolytic, anti-inflammatory, and antioxidant properties.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 172
Incorrect
-
Coronary arteries fill up during
Your Answer:
Correct Answer: Diastole
Explanation:During contraction of the ventricular myocardium (systole), the subendocardial coronary vessels (the vessels that enter the myocardium) are compressed due to the high ventricular pressures. This compression results in momentary retrograde blood flow (i.e., blood flows backward toward the aorta) which further inhibits perfusion of myocardium during systole. However, the epicardial coronary vessels (the vessels that run along the outer surface of the heart) remain open. Because of this, blood flow in the sub endocardium stops during ventricular contraction. As a result, most myocardial perfusion occurs during heart relaxation (diastole) when the subendocardial coronary vessels are open and under lower pressure.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 173
Incorrect
-
Regarding glomus cells, which of the following is true?
Your Answer:
Correct Answer: Contain catecholamines
Explanation:The carotid body detects changes in the composition of arterial blood flowing through it, mainly the partial pressure of oxygen, but also of carbon dioxide. Furthermore, it is also sensitive to changes in pH and temperature.The carotid body is made up of two types of cells, called glomus cells: Glomus type I/chief cells release a variety of neurotransmitters, including acetylcholine, ATP, and dopamine that trigger EPSPs in synapsed neurons leading to the respiratory centre.Glomus type II/sustentacular cells resemble glia, express the glial marker S100 and act as supporting cells.
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This question is part of the following fields:
- Medicine
- Respiratory
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Question 174
Incorrect
-
Which one of the following is a risk factor for torsade de pointes?
Your Answer:
Correct Answer: Hypothermia
Explanation:The following is a list of factors associated with an increased tendency toward torsades de pointes:- Hypokalaemia (low blood potassium)- Hypomagnesemia (low blood magnesium)- Hypocalcaemia (low blood calcium)- Bradycardia (slow heartbeat)- Heart failure- Left ventricular hypertrophy- Hypothermia- Subarachnoid haemorrhage- Hypothyroidism
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 175
Incorrect
-
The main reason for the prolonged effect of the withdrawal reflex is:
Your Answer:
Correct Answer: Multiple connections between afferent and efferent neurons
Explanation:The withdrawal reflex is a spinal reflex that protects the body from harmful stimuli. Spinal reflexes are mostly monosynaptic and are mediated by a simple reflex arc. Withdrawal reflex is mediated by a polysynaptic reflex resulting in stimulation of many motor neurons in order to establish a quick and prolonged response.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 176
Incorrect
-
Where do the portal hypophysial vessels arise?
Your Answer:
Correct Answer: Median eminence
Explanation:The hypothalamic-hypophysial portal system connects the brain to the anterior pituitary. It is made up of two capillary beds, one in the median eminence and the other in the anterior pituitary. Blood from the plexus of the median eminence is carried by portal veins, draining into the cavernous and posterior intercavernous sinuses. This system delivers hypothalamic hormones to their target cells.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 177
Incorrect
-
In the clotting mechanism, activation of factor IX can occur through the direct actions of:
Your Answer:
Correct Answer: Factor VIIa & XIa
Explanation:Factor IX is processed to remove the signal peptide, glycosylated and then cleaved by factor XIa (of the contact pathway) or factor VIIa (of the tissue factor pathway). When activated into factor IXa, in the presence of Ca2+, membrane phospholipids, and a Factor VIII cofactor, it hydrolyses one arginine-isoleucine bond in factor X to form factor Xa. Factor IX is inhibited by antithrombin.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 178
Incorrect
-
The postextrasystolic potentiation of myocardial contractility is due to:
Your Answer:
Correct Answer: Increase in intracellular Ca2+
Explanation:The postextrasystolic potentiation of myocardial contractility Is not due to ventricular filling. It occurs in isolated locations in the heart and is due to increase availability of intracellular calcium.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 179
Incorrect
-
Where is the most erythropoietin produced?
Your Answer:
Correct Answer: Kidneys
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:
- Haematology
- Medicine
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Question 180
Incorrect
-
Cholinergic nerves from the vagus innervate the SA and AV nodes via which receptor in the heart?
Your Answer:
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 181
Incorrect
-
Regarding the surface anatomy of the orifices of the heart, where is the aortic valve located?
Your Answer:
Correct Answer: Opposite the left 3rd intercostal space to the left of the sternum
Explanation:The aortic valve is situated in the left 3rd intercostal space just beneath the sternum.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 182
Incorrect
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The primary auditory cortex is:
Your Answer:
Correct 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
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Question 183
Incorrect
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Depolarization spreads rapidly through cardiac muscle fibers because of the presence of:
Your Answer:
Correct 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 184
Incorrect
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The endothelium of the sinusoids has the following important function:
Your Answer:
Correct Answer: Highly fenestrated, large subendothelial spaces, many macrophages
Explanation:Substances absorbed in the intestines reach the liver via the portal vein and contain toxic substances that needs to be detoxified in hepatocytes. Thus, hepatic sinusoids are fenestrated and contain large spaces which allows passage of substances freely. These fenestrations are rich in Kupffer cells which are macrophages.
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This question is part of the following fields:
- Hepatobiliary
- Medicine
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Question 185
Incorrect
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Question 186
Incorrect
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Which of the following suggests the presence of mitral regurgitation as well as mitral stenosis?
Your Answer:
Correct Answer: Displaced apex beat
Explanation:Mitral stenosis on its own does not lead to left ventricular dilatation and hence a displaced apex beat. Thus a displaced apex beat is suggestive of mixed mitral disease. The other options occur in mitral stenosis.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 187
Incorrect
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A 22-year-old female comes to you for counselling regarding the initiation of combined oral contraceptive pill. Which of the following statements is correct?
Your Answer:
Correct Answer: She will still be protected against pregnancy if she takes amoxicillin for a lower respiratory tract infection while on the combined pill
Explanation:The true statement among the given options is that she will still be protected against pregnancy if she takes amoxicillin for a lower respiratory tract infection while on the combined pill.Other than enzyme-inducing antibiotics such as rifampicin, antibiotics do not reduce the efficacy of the combined oral contraceptive pill.It was previously advised that barrier methods of contraception should be used if taking an antibiotic while using the contraceptive pill, due to concerns that antibiotics might reduce the absorption of the pill. This is now known to be untrue. However, if the absorptive ability of the gut is compromised for another reason, such as severe diarrhoea or vomiting, or bowel disease, this may affect the efficacy of the pill.The exception to the antibiotic rule is that hepatic enzyme-inducing antibiotics such as rifampicin and rifaximin do reduce the efficacy of the pill. Other enzyme-inducing drugs, such as phenytoin, phenobarbital, carbamazepine or St John’s Wort can also reduce the effectiveness of the pill.Other options:The combined pill is often prescribed for women with heavy periods as it can make them lighter and less painful. There is no evidence that women on the combined pill put on any significant weight, although they may experience bloating at certain times in the course. Women on the pill require monitoring of their blood pressure. There are multiple different types of combined pills.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 188
Incorrect
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Mutation in RB can lead to the formation of which cancer?
Your Answer:
Correct 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 189
Incorrect
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Which ion channel does not contribute to the myocardial action potential?
Your Answer:
Correct Answer: Chloride channel
Explanation:The upstroke in the cardiac action potential is due to opening of the sodium channels and an influx of sodium into the cell. The initial repolarization phase is due to transient opening of the potassium channels along with calcium channels. Influx of calcium causes the prolonged plateau phase of the action potential. Delayed opening of the rectifier potassium channel and delayed closure of the calcium channel leads to the repolarization phase of cardiac action potential.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 190
Incorrect
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Where is the carotid sinus located?
Your Answer:
Correct Answer: After the bifurcation of the carotid artery, on the internal carotid
Explanation:The carotid sinus is a small dilation in the internal carotid artery just above its bifurcation into the external and internal carotid branch. Baroreceptors are present at this dilation.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 191
Incorrect
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A 42 year old female presents with morning stiffness that usually takes an hour to settle and a one year history of intermittent pain and swelling of the small joints of her hands. Examination reveals symmetric soft tissue swelling over the PIP and MCP joints and rheumatoid nodules on the elbows. There is also an effusion of both wrists. Lab results are positive for rheumatoid factor. X-ray of the wrists and hands shows erosions and bony decalcification. NSAIDs are started and the patient is referred to a rheumatologist for consideration of DMARD. Previous history is significant for TB. Which of the following should be avoided?
Your Answer:
Correct Answer: Infliximab
Explanation:Anti-TNF-α therapy is effective for patients with arthritis but it can oftentimes lead to the reactivation of latent TB. Hence it should be used with great caution in patients with a past history of TB or current infection.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 192
Incorrect
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An 80 year old female, previously diagnosed with polymyalgia rheumatica 18 months back, presents to the outpatient clinic with bilateral shoulder stiffness and generalized myalgia. The ESR was found to be 60mm/1st hour at the time of presentation. Prednisolone therapy was initiated at a daily dose of 15 mg along with Calcium and Vitamin supplementation. She reported resolution of her symptoms in one week. However the symptoms relapsed when the prednisolone dose was reduced below the current dose of 12.5 mg daily. How should she be ideally managed?
Your Answer:
Correct Answer: Continue the current dose of prednisolone and start methotrexate
Explanation:Polymyalgia rheumatica, a syndrome characterized by proximal muscle pain and stiffness in older persons, generally is treated with prednisone. Dosages of 15 to 25 mg of prednisone per day can reduce inflammation considerably, although many patients relapse when therapy is tapered. Long-term (18 to 36 months) steroid treatment has been recommended by several studies, but this can result in multiple side effects, including osteoporosis, hypertension, cataracts, and hyperglycaemia. Methotrexate has been used to reduce inflammation in rheumatoid arthritis, systemic vasculitis, and giant cell arteritis, and in some studies has been combined with prednisone to treat polymyalgia rheumatica, decreasing the duration of treatment.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 193
Incorrect
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Select the correct pairing regarding the surface of the cerebral hemispheres.
Your Answer:
Correct Answer: Parietal lobe : primary somatosensory cortex
Explanation:Parietal lobe: The primary somatosensory cortex is located in the postcentral gyrus of the parietal lobe. It is responsible for processing sensory information from the body.
Frontal lobe: The primary motor cortex is located in the precentral gyrus of the frontal lobe. The frontal lobe also contains the premotor cortex, which is involved in planning movements. The primary visual cortex is located in the occipital lobe, not the frontal lobe.
Temporal lobe: The primary auditory cortex is located in the superior temporal gyrus of the temporal lobe. The primary motor and premotor cortices are located in the frontal lobe, not the temporal lobe.
Occipital lobe: The primary visual cortex is located in the occipital lobe. The primary auditory cortex is located in the temporal lobe, not the occipital lobe.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 194
Incorrect
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An elderly man presents with fever of 38°C and a very severe headache. His BP is 85/50 mm Hg. He has neck stiffness and photophobia. What is the most appropriate management?
Your Answer:
Correct Answer: CT head
Explanation:In elderly patients, symptoms suggestive of meningitis could be due to an intracranial mass lesion (such as abscess, tumour or an intracerebral haematoma). Therefore elderly patients are increased risk of cerebral herniation from an LP. A CT head should be done before an LP to exclude a mass lesion.
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This question is part of the following fields:
- Geriatrics
- Medicine
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Question 195
Incorrect
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Antibiotic resistance may happen by:
Your Answer:
Correct Answer: By enzymes which inactivate the drug
Explanation:The three main mechanisms of antibiotic resistance are, enzymatic degradation of antibacterial drugs, alteration of bacterial proteins that are antimicrobial targets, and changes in membrane permeability to antibiotics.
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This question is part of the following fields:
- Infectious Diseases
- Medicine
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Question 196
Incorrect
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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:
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 197
Incorrect
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Which of the following vitamin deficiencies is associated with xerophthalmia?
Your Answer:
Correct 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
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Question 198
Incorrect
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Which of the following is the most common clinical feature of carbon monoxide poisoning?
Your Answer:
Correct Answer: Headache
Explanation:Carbon monoxide (CO) poisoning:It is considered as the great imitator of other diseases as the patients present with a myriad of symptoms. The carbon monoxide diffuses rapidly across the pulmonary capillary membrane binding to the haem molecule with a very high affinity (240 times that of oxygen) forming carboxy-haemoglobin (COHb). Non-smokers have a baseline COHb of ,3% while smokers have a baseline COHb of 10-15%.Clinical features of carbon monoxide toxicity:Headache: 90% of cases (most common clinical feature)Nausea and vomiting: 50%Vertigo: 50%Confusion: 30%Subjective weakness: 20%Severe toxicity: ‘pink’ skin and mucosa, hyperpyrexia, arrhythmias, extrapyramidal features, coma, deathCherry red skin is a sign of severe toxicity and is usually a post-mortem finding.Management• 100% oxygen• Hyperbaric oxygen therapy (HBOT)The use of Hyperbaric oxygen therapy (HBOT) for treatment mild to moderate CO poisoning is not routine.The selection criteria for HBOT in cases of CO poisoning include:• COHb levels > 20-25%• COHb levels > 20% in pregnant patient • Loss of consciousness• Severe metabolic acidosis (pH <7.1)• Evidence of end-organ ischemia (e.g., ECG changes, chest pain, or altered mental status)
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 199
Incorrect
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Which of the following pairing is correct:
Your Answer:
Correct Answer: Herpes simplex type I and herpes encephalitis
Explanation:Herpes simplex virus is likely the most common cause of Mollaret’s meningitis, and, in worse case scenarios, can lead to a potentially fatal case of herpes simplex encephalitis. The eighth human herpesvirus or HHV-8 causes Kaposi’s sarcoma and Herpes simplex type 2 is responsible for most primary genital herpes.
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This question is part of the following fields:
- Infectious Diseases
- Medicine
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Question 200
Incorrect
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A patient who has recently been diagnosed with SLE undergoes serum testing. A rise in which of the following antibodies would indicate severe systemic involvement?
Your Answer:
Correct Answer: Anti double-stranded DNA antibodies
Explanation:Anti ds-DNA antibodies are very specific for SLE and their presence most often indicates systemic spread of the disease. These antibodies are present in about 30 percent of the total cases of SLE.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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SESSION STATS - PERFORMANCE PER SPECIALTY
