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Question 1
Incorrect
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An exaggerated response to a noxious stimulus is called:
Your Answer: Hyperesthesia
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 2
Incorrect
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Where is thyroglobulin produced?
Your Answer:
Correct Answer: Thyrocytes
Explanation:Thyroglobulin, or Tg, is a protein that functions as the precursor to thyroid hormones. It is synthesized by thyrocytes and then secreted into the colloid. It also functions as a negative-feedback regulator of thyroid hormone biosynthesis.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 3
Incorrect
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Choose the correct answer: fibers in the superior cerebellar peduncle:
Your Answer:
Correct Answer: Are mainly ventral spinocerebellar tracts from the cerebellar nuclei to the thalamus and red nucleus
Explanation:There are three cerebellar peduncles with different connections and functions. The three are mainly, superior, middle and inferior. The superior cerebellar peduncle is also known as the “Brachium conjunctivum”. It predominantly contains efferent fibers from the cerebellar nuclei, as well as some afferents from the spinocerebellar tract. The efferent pathways include cerebellorubral, dentatothalamic, and fastigioreticular fibers. These are tracts projecting from the deep cerebellar nuclei to the thalamus and red nucleus. The middle cerebellar peduncle connects to the pontine nucleus and the dorsal spinocerebellar tracts run through the superior cerebellar peduncle.
The superior cerebellar peduncle contains vital afferent and efferent fibers including cerebellothalamic, cerebellorubral and ventrospinocerebellar tracts.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 4
Incorrect
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Which is NOT true of vitiligo?
Your Answer:
Correct Answer: A positive family history is not a risk factor
Explanation:The cause of Vitiligo is typically unknown. It is believed to be due to genetic susceptibility that is triggered by an environmental factor such that an autoimmune disease occurs. This results in the destruction of skin pigment cells. Risk factors include a family history of the condition or other autoimmune diseases, such as hyperthyroidism, alopecia areata, and pernicious anaemia. Vitiligo is classified into two main types: segmental and non-segmental. Most cases are non-segmental meaning they affect both sides and typically get worse with time. The prevalence of vitiligo is 0.5-1% of populations worldwide. Typical sites include backs of hands, wrists, knees, neck and around body orifices. The Koebner phenomenon refers to skin lesions appearing on lines of trauma. This occurs in vitiligo secondary to scratching.
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This question is part of the following fields:
- Dermatology
- Medicine
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Question 5
Incorrect
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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 6
Incorrect
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Among the following which is the beneficial effect of nitro-glycerine?
Your Answer:
Correct Answer: Dilation of systemic veins
Explanation:Dilation of systemic veins is a beneficial effect of nitro-glycerine.Administration of nitro-glycerine results in the dilation of systemic veins and decrease of myocardial wall tension and oxygen demand. Dilatation of systemic veins can cause reduced systemic vascular resistance leading to reduced cardiac workload thus reducing anginal symptoms secondary to demand ischemia.This is accompanied by vasodilation of large and medium-sized coronary arteries with increased coronary blood flow to the sub endocardium.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 7
Incorrect
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Question 8
Incorrect
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The areas of extensive series of sarcoplasmic folds known as intercalated discs always occur at what portion of the muscle fiber?
Your Answer:
Correct Answer: Z lines
Explanation:The muscle fibers of the heart branch and interdigitate, but one complete unit is surrounded by a cell membrane. The place where one muscle fiber abuts the other, the cell membrane of both the fibers run parallel to each other through a series of extensive folds. These areas always occur on the Z lines and are known as intercalated discs.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 9
Incorrect
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A 28 year old woman presents with painful genital ulceration. She reports that these attacks have been recurrent over the past 4 years. She has been treated previously with oral acyclovir but this has had little effect on the duration of her symptoms. Over the past year, she has noticed almost weekly attacks of mouth ulcers that heal slowly. Past medical history is significant for treatment of thrombophlebitis two years ago. Which of the following is the most likely diagnosis?
Your Answer:
Correct Answer: Behcet's syndrome
Explanation:Behçet disease is a rare vasculitic disorder that is characterized by a triple-symptom complex of recurrent oral aphthous ulcers, genital ulcers, and uveitis. The systemic manifestations can be variable. Ocular disease has the greatest morbidity, followed by vascular disease generally from active vasculitis. Cutaneous manifestations can occur in up 75% of patients with Behcet disease and can range from acneiform lesions, to nodules and erythema nodosum. GI manifestations can be severe. Differentiating Behçet disease from active inflammatory bowel disease can be clinically difficult. Herpes would have ideally responded to acyclovir. Sarcoidosis does not have genital and oral ulcerations.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 10
Incorrect
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Which of the following statements regarding psoriasis is incorrect?
Your Answer:
Correct Answer: Mediated by type 2 helper T cells
Explanation:Psoriasis is a long-lasting autoimmune disease characterized by patches of skin typically red, dry, itchy, and scaly. Psoriasis can affect the nails and produces a variety of changes in the appearance of finger and toe nails including pitting and onycholysis. Nail psoriasis occurs in 40–45% of people with psoriasis affecting the skin and has a lifetime incidence of 80–90% in those with psoriatic arthritis. Psoriasis is mediated by type 1 helper T cells which are involved in the cell mediated response.
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This question is part of the following fields:
- Dermatology
- Medicine
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Question 11
Incorrect
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A 50-year-old male was brought to the ER after the accidental consumption of 300 ml of diethylene glycol. Blood investigations were suggestive of metabolic acidosis and renal failure. What is the appropriate management in this patient?
Your Answer:
Correct Answer: Haemodialysis and oral ethanol
Explanation:Among the given options the most appropriate management in this patient would be ethanol and haemodialysis.Ethanol competes with ethylene glycol for alcohol dehydrogenase and thus, helps manage a patient with ethylene glycol toxicity.Ethylene glycol is a type of alcohol used as a coolant or antifreezeFeatures of toxicity are divided into 3 stages:Stage 1: (30 min to 12 hours after exposure) Symptoms similar to alcohol intoxication: confusion, slurred speech, dizziness (CNS depression)Stage 2: (12 – 48 hours after exposure) Metabolic acidosis with a high anion gap and high osmolar gap. Also tachycardia, hypertensionStage 3: (24 – 72 hours after exposure) Acute renal failureManagement has changed in recent times:Fomepizole, an inhibitor of alcohol dehydrogenase, is now used first-line in preference to ethanol.Ethanol has been used for many years works by competing with ethylene glycol for the enzyme alcohol dehydrogenase this limits the formation of toxic metabolites (e.g. glycolaldehyde and glycolic acid) which are responsible for the hemodynamic/metabolic features of poisoning.Haemodialysis has a role in refractory cases.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 12
Incorrect
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Regarding integrins, which option is false?
Your Answer:
Correct Answer: Play no role in cell signalling.
Explanation:Integrins are transmembrane receptors that facilitate cell-extracellular matrix (ECM) adhesion. Upon ligand binding, integrins activate signal transduction pathways that mediate cellular signals such as regulation of the cell cycle, organization of the intracellular cytoskeleton, and movement of new receptors to the cell membrane. Integrins are obligate heterodimers, meaning that they have two subunits: α (alpha) and β (beta). Integrins play an important role in cell signalling by modulating the cell signalling pathways of transmembrane protein kinases such as receptor tyrosine kinases (RTK).
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This question is part of the following fields:
- Cell Biology
- Medicine
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Question 13
Incorrect
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A 72 year old female, known with rheumatoid arthritis for last 17 years, presents with recurrent attacks of red eyes with a sensation of grittiness. Which of the following is most likely cause of the red eyes?
Your Answer:
Correct Answer: keratoconjunctivitis sicca
Explanation:Rheumatoid arthritis is an inflammatory systemic disease associated with some extraarticular manifestations. Keratoconjunctivitis sicca, episcleritis, scleritis, corneal changes, and retinal vasculitis are the most common ocular complications among extraarticular manifestations of RA. The overall prevalence of keratoconjunctivitis sicca also known as dry eye syndrome among patients of RA is 21.2% and is the most common with sense of grittiness in the eyes.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 14
Incorrect
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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 15
Incorrect
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Which of the following conditions is least likely to exhibit the Koebner phenomenon?
Your Answer:
Correct Answer: Lupus vulgaris
Explanation:The Koebner phenomenon refers to skin lesions appearing on lines of trauma, exposure to a causative agents including: molluscum contagiosum, warts and toxicodendron dermatitis or secondary to scratching rather than an infective or chemical cause include vitiligo, psoriasis, lichen planus, lichen nitidus, pityriasis rubra pilaris, and keratosis follicularis (Darier disease).
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This question is part of the following fields:
- Dermatology
- Medicine
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Question 16
Incorrect
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During bone growth-the epiphysis are separated from the diaphysis by actively proliferating cartilage known as:
Your Answer:
Correct Answer: Epiphysial plate
Explanation:The epiphysial plate, physis, or growth plate, is a hyaline cartilage plate located near the ends of long bones; it consists of growing tissue. It is found in children and teenagers; in adults, it is replaced by an epiphysial line or epiphysial closure. The epiphysial plate is divided into zones: zone of reserve, proliferation, maturation and hypertrophy, calcification, and ossification.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 17
Incorrect
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In which stage of mitosis are the chromosomes most obvious or prominent?
Your Answer:
Correct Answer: Metaphase
Explanation:Prophase begins when the nucleus envelope disintegrates and the chromosomes start to condense. The chromosomes consist of two sister chromatids that are joined at a constriction known as centromere. When the cell reaches the metaphase the chromosomes are completely condensed and ready to align on the equatorial plate.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 18
Incorrect
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Myocardial contractility is improved by:
Your Answer:
Correct Answer: Caffeine
Explanation:Caffeine and other theophyllines breakdown cAMP and have a positive ionotropic effect on the heart. Drugs like quinidine, procainamide and conditions like hypoxia and hypercapnia decreases the contractility of the heart.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 19
Incorrect
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What is the function of the macula densa, located in the wall of the thick ascending limb?
Your Answer:
Correct Answer: Tubuloglomerular feedback.
Explanation:Macula densa cells sense changes in sodium chloride level, and will trigger an autoregulatory response to increase or decrease reabsorption of ions and water to the blood (as needed) in order to alter blood volume and return blood pressure to normal. Tubuloglomerular feedback is one of several mechanisms the kidney uses to regulate glomerular filtration rate (GFR). It involves the concept of purinergic signalling, in which an increased distal tubular sodium chloride concentration causes a basolateral release of adenosine from the macula densa cells. This initiates a cascade of events that ultimately brings GFR to an appropriate level.
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This question is part of the following fields:
- Medicine
- Renal
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Question 20
Incorrect
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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 21
Incorrect
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Which hormone is associated with the temperature surge in hot flushes?
Your Answer:
Correct Answer: LH
Explanation:Luteinizing hormone or LH is a hormone produced by the anterior pituitary gland. Studies have shown surges in LH levels during menopausal hot flushes, suggesting that a pulsatile release of LH is responsible for increased hypothalamic norepinephrine activity, causing the hot flushes.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 22
Incorrect
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The oesophagus is lined by
Your Answer:
Correct Answer: Stratified squamous epithelium
Explanation:The wall of the oesophagus from the lumen outwards consists of mucosa, submucosa (connective tissue), layers of muscle fibers between layers of fibrous tissue, and an outer layer of connective tissue. The mucosa is a stratified squamous epithelium of around three layers of squamous cells, which contrasts to the single layer of columnar cells of the stomach. The transition between these two types of epithelium is visible as a zig-zag line. Most of the muscle is smooth muscle although striated muscle predominates in its upper two thirds.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 23
Incorrect
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In the Fick‘s method of measuring cardiac output, the arterial oxygen content can be measured in a sample obtained from
Your Answer:
Correct Answer: The pulmonary vein
Explanation:In Fick’s original method, the following variables are measured:VO2, oxygen consumption in ml of pure gaseous oxygen per minute. This may be measured using a spirometer within a closed rebreathing circuit incorporating a CO2 absorberCa, the oxygen concentration of blood taken from the pulmonary vein (representing oxygenated blood)Cv, the oxygen concentration of blood from an intravenous cannula (representing deoxygenated blood)From these values, we know that:VO2 = (CO x Ca) – (CO x Cv)where CO = Cardiac Output, Ca = Oxygen concentration of arterial blood and Cv = Oxygen concentration of mixed venous blood.This allows us to sayCO = VO2/{Ca – Cv}and hence calculate cardiac output.Note that (Ca – Cv) is also known as the arteriovenous oxygen difference.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 24
Incorrect
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Question 25
Incorrect
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A 40-year-old man is admitted to the Emergency Department in a confused state. He tells you that he consumed two bottles of antifreeze. On examination, his pulse is 120 bpm and blood pressure is 140/90 mmHg. An arterial blood gas analysis shows uncompensated metabolic acidosis. He is transferred to the high dependency unit and ethanol is given via a nasogastric tube. How does ethanol help this patient?
Your Answer:
Correct Answer: Competes with ethylene glycol for alcohol dehydrogenase
Explanation:Ethanol competes with ethylene glycol for alcohol dehydrogenase and thus, helps manage a patient with ethylene glycol toxicity.Ethylene glycol is a type of alcohol used as a coolant or antifreezeFeatures of toxicity are divided into 3 stages:Stage 1: (30 min to 12 hours after exposure) Symptoms similar to alcohol intoxication: confusion, slurred speech, dizziness (CNS depression)Stage 2: (12 – 48 hours after exposure) Metabolic acidosis with a high anion gap and high osmolar gap. Also tachycardia, hypertensionStage 3: (24 – 72 hours after exposure) Acute renal failureManagement has changed in recent times:Fomepizole, an inhibitor of alcohol dehydrogenase, is now used first-line in preference to ethanol.Ethanol has been used for many years works by competing with ethylene glycol for the enzyme alcohol dehydrogenase this limits the formation of toxic metabolites (e.g. glycolaldehyde and glycolic acid) which are responsible for the hemodynamic/metabolic features of poisoning.Haemodialysis has a role in refractory cases.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 26
Incorrect
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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 27
Incorrect
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Most of the venous blood returns to the heart through the:
Your Answer:
Correct Answer: Coronary sinus and anterior cardiac veins
Explanation:Most of the venous blood returns to the heart via the coronary sinus and the anterior cardiac veins which drain into the right atrium.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 28
Incorrect
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With regard to the endothelial structure, the epithelium constitute:
Your Answer:
Correct Answer: Simple squamous
Explanation:The single layer of squamous epithelium lining the heart and blood vessels is known as the endothelium.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 29
Incorrect
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Which of the following is a precursor to the tissue macrophage?
Your Answer:
Correct Answer: Monocyte
Explanation:Monocytes are a type of white blood cell, or leukocyte. They are the largest type of leukocyte and can differentiate into macrophages or dendritic cells.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 30
Incorrect
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Renin is secreted by which of the following cells?
Your Answer:
Correct Answer: Juxtaglomerular cells
Explanation:The juxtaglomerular cells are cells in the kidney that synthesize, store, and secrete the enzyme renin. They are specialized smooth muscle cells mainly in the walls of the afferent arterioles, and some in the efferent arterioles, that deliver blood to the glomerulus.
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This question is part of the following fields:
- Medicine
- Renal
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Question 31
Incorrect
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Choose the most correct answer, what reduces affinity for oxygen in haemoglobin?
Your Answer:
Correct Answer: All the options are true
Explanation:The strength with which oxygen binds to haemoglobin is affected by several factors. These factors shift or reshape the oxyhaemoglobin dissociation curve. A rightward shift indicates that the haemoglobin under study has a decreased affinity for oxygen. The causes of shift to right can be remembered using the mnemonic, CADET, face Right! for CO2 and CO, Acid (H+), 2,3-DPG, Exercise and Temperature.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 32
Incorrect
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Which of the following acute phase reactants increases the most dramatically in the first hour following injury?
Your Answer:
Correct Answer: C-reactive protein
Explanation:Measurement of acute-phase proteins, especially C-reactive protein, is a useful marker of inflammation. It correlates with the erythrocyte sedimentation rate (ESR), however not always directly. This is due to the ESR being largely dependent on elevation of fibrinogen, an acute phase reactant with a half-life of approximately one week. This protein will therefore remain higher for longer despite removal of the inflammatory stimuli. In contrast, C-reactive protein (with a half-life of 6-8 hours) rises rapidly and can quickly return to within the normal range if treatment is employed.
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This question is part of the following fields:
- Immunology
- Medicine
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Question 33
Incorrect
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Which of the following results in the resting membrane potential of a myocyte?
Your Answer:
Correct Answer: Activation of outward K+ channels
Explanation:Phase 0 is caused by the sodium current. Voltage gated sodium channels open leading to the influx of sodium into the cardiac muscle cell. Phase 1 is the rapid transient repolarization phase which is caused by the inactivation of the voltage gated sodium channels and opening of the voltage gated potassium channels along with opening of the slow calcium channels. Phase 2 which is the plateau is caused by opening of the slow calcium channels. Phase 4 is caused by closing of the slow calcium channels and opening of the potassium channels leading to efflux of potassium leading to the establishment of the resting membrane potential.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 34
Incorrect
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Which one of the following statements best describes a type II statistical error?
Your Answer:
Correct Answer: The null hypothesis is accepted when it is false
Explanation:In statistical hypothesis testing there are 2 types of errors:- type I: the null hypothesis is rejected when it is true – i.e. Showing a difference between two groups when it doesn’t exist, a false positive. – type II: the null hypothesis is accepted when it is false – i.e. Failing to spot a difference when one really exists, a false negative.
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This question is part of the following fields:
- Medicine
- Research Skills
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Question 35
Incorrect
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A 35-year-old male presented to the ER after being rescued from a house fire. He complained of feeling dizzy and having a worsening headache. On examination, he was dyspnoeic, drowsy and confused. There was no evidence of facial burns and no stridor. He was normotensive, tachycardic (pulse rate: 102 bpm), tachypnoeic (respiratory rate: 35/min) and had O2 saturation of 100% in room air. His venous blood gas results are given below: pH - 7.28pCO2 - 3.5 kPapO2 - 15.9 kPaNa+ - 139 mmol/LK+ - 4.5 mmol/LBicarbonate - 11 mmol/LChloride - 113 mmol/LLactate - 13.6 mmol/LKeeping in mind the likely diagnosis, which among the following is the most appropriate intervention for this patient?
Your Answer:
Correct Answer: Intravenous hydroxocobalamin
Explanation:The most appropriate intervention in this patient is intravenous hydroxocobalamin.The clinical scenario provided is suggestive of acute cyanide toxicity secondary to burning plastics in the house fire. Cyanide ions inhibit mitochondrial cytochrome oxidase, preventing aerobic respiration. This manifests in normal oxygen saturations, a high pO2 and flushing (or ‘brick red’ skin) brought on by the excess oxygenation of venous blood. In the question above it is important to note that the blood gas sample given is venous rather than arterial. His blood gas also demonstrates an increased anion gap, consistent with his high lactate (generated by anaerobic respiration due to the inability to use available oxygen).The recommended treatment for moderate cyanide toxicity in the UK is one of three options: sodium thiosulfate, hydroxocobalamin or dicobalt edetate. Among the options given is hydroxocobalamin and this is, therefore, the correct answer. Hydroxocobalamin additionally has the best side-effect profile and speed of onset compared with other treatments for cyanide poisoning.Other options:- Intubation would be appropriate treatment in the context of airway burns but this patient has no evidence of these, although close monitoring would be advised. – High-flow oxygen is the treatment for carbon monoxide poisoning – a sensible differential, but this man’s very high lactate and high venous pO2 fit better with cyanide toxicity. Intravenous dexamethasone would be another treatment for airway oedema once an endotracheal tube had been placed. – Intravenous sodium nitroprusside is a treatment for high blood pressure that can cause cyanide poisoning, and would, therefore, be inappropriate.Note:Cyanide may be used in insecticides, photograph development and the production of certain metals. Toxicity results from reversible inhibition of cellular oxidizing enzymesClinical presentation:Classical features: brick-red skin, the smell of bitter almondsAcute: hypoxia, hypotension, headache, confusionChronic: ataxia, peripheral neuropathy, dermatitisManagement:Supportive measures: 100% oxygenDefinitive: hydroxocobalamin (intravenously), also a combination of amyl nitrite (inhaled), sodium nitrite (intravenously), and sodium thiosulfate (intravenously).
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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 pontine tegmentum as part of the midbrain, contains which cranial nerve nuclei?
Your Answer:
Correct Answer: CN 5 to 8
Explanation:The pontine tegmentum also known as dorsal pons is located within the brain stem. Several cranial nerve nuclei are located in the pontine tegmentum. The nuclei of CN V, CN VI, CN VII and CNVIII are located in the pontine tegmentum.
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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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A 28 year old male arrives at the clinic complaining of fever, arthralgia and urethritis. On examination, the ankle is swollen and there is a pustular rash on the dorsal foot. What is the most likely diagnosis?
Your Answer:
Correct Answer: Disseminated gonorrhoea
Explanation:DGI presents as two syndromes: 1) a bacteremic form that includes a triad of tenosynovitis, dermatitis, and polyarthralgias without purulent arthritis and 2) a septic arthritis form characterized as a purulent arthritis without associated skin lesions. Many patients will have overlapping features of both syndromes. Time from infection to clinical manifestations may range from 1 day to 3 months. There is no travel history and the rash of Lyme disease is not purulent. Reactive arthritis presents with conjunctivitis, urethritis and arthritis usually with a red hot tender and swollen joint.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 38
Incorrect
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What is the most important way in which heat is lost from the body?
Your Answer:
Correct Answer: Radiation and conduction
Explanation:The body maintains a constant core temperature by balancing heat loss and heat gain. The mechanisms of heat loss are: radiation, evaporation, convection and conduction. Out of these mechanisms, the most important under normal conditions are radiation, through which body heat is given off to the surrounding atmosphere; and conduction, in which the body releases heat into the objects it comes into contact with.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 39
Incorrect
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Where in the gastrointestinal tract are valvulae conniventes?
Your Answer:
Correct Answer: Jejunum
Explanation:The circular folds (valves of Kerckring or valvulae conniventes) are large valvular flaps projecting into the lumen of the small intestine.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 40
Incorrect
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Regarding the formation of CSF, which of the following is true?
Your Answer:
Correct Answer: Its composition resembles that of brain ECF
Explanation:In normal adults CSF volume is around 125ml to 150ml. Turnover of entire volume of cerebrospinal fluid a day is about 3 to 4 times a day. Composition of CSF is similar to that of plasma except that CSF is nearly protein-free compared with plasma and has a different electrolyte level. About 80% of CSF is produced by the choroid plexus. It is also produced by a single layer of column shaped ependymal cells. The composition and rate of CSF generation depends on several factors and is influenced by hormones and the content and pressure of blood and CSF.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 41
Incorrect
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The pressure in the portal circulation is normally adjusted in the:
Your Answer:
Correct Answer: Sinusoids
Explanation:The pressure in the portal circulation depends on the pressure of the hepatic sinusoids mainly because the direction of transport of nutrients in the portal vein occurs from the portal vein to the hepatic sinusoids.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 42
Incorrect
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In the body what are fatty acids broken down to?
Your Answer:
Correct Answer: Acetyl Co A
Explanation:Fatty acids are broken down into acetyl Co A. The acetyl-CoA produced by beta oxidation enters the citric acid cycle in the mitochondrion by combining with oxaloacetate to form citrate.
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This question is part of the following fields:
- Cell Biology
- Medicine
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Question 43
Incorrect
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A 20-year-old female has been admitted with an acute infection. She gives a history suggestive of hypersensitivity to amoxicillin. After consultation with the allergy specialist, she has now been diagnosed with an IgE mediated penicillin allergy. Which of the following drugs should be avoided in this patient?
Your Answer:
Correct Answer: Cefalexin
Explanation:Cefalexin should be avoided in this patient.This patient is known to have a severe penicillin allergy. None of the above antibiotics are penicillin based. However, 0.5 – 6.5% of patients who are proven to have an IgE mediated penicillin allergy will also be allergic to cephalosporins, including cefalexin. Penicillin, cephalosporins, and carbapenems are all members of the beta-lactam group of antibiotics and share a common beta-lactam ring. There is, therefore, a small risk of allergy cross-over between all these antibiotics. The rates of allergy cross-over are lower with second and third-generation cephalosporins than first-generation cephalosporins such as cefalexin.It is important to question the patient carefully to ascertain what symptoms they had on exposure to penicillin. Symptoms such as an urticarial rash or itching make it more likely that they have an IgE mediated allergy.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 44
Incorrect
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Question 45
Incorrect
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A 72-year-old with varicose veins complains of swollen, red, itchy legs. Which is the most likely diagnosis?
Your Answer:
Correct Answer: Varicose eczema
Explanation:Varicose eczema is a common problem, particularly in elderly patients due to stasis or blood pooling from insufficient venous return; the alternative name of varicose eczema comes from a common cause of this being varicose veins. It is often mistaken for cellulitis, but cellulitis is rarely bilateral and is painful rather than itchy.
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This question is part of the following fields:
- Dermatology
- Medicine
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Question 46
Incorrect
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Pacemaker cells in the SA node and the AV node are connected by?
Your Answer:
Correct Answer: Gap junctions
Explanation:Gap junctions allows for rapid propagation of the action potential from one cell to the other. The cells of the heart are connected by gap junctions.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 47
Incorrect
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Telomerase is active in all of the following cells, except:
Your Answer:
Correct Answer: Certain liver cells
Explanation:Telomerase is an enzyme that adds repetitive nucleotide sequences to the ends of chromosomes (telomeres), preventing their shortening during cell division. Telomerase activity is crucial for cells that divide frequently and need to maintain their telomere length for continued proliferation. These include:
- Stem cells: They have high telomerase activity to maintain their long-term proliferative capacity.
- Germ cells: These cells also have active telomerase to ensure the stability of genetic material across generations.
- Certain white blood cells: Some immune cells, particularly those that need to proliferate in response to infection, show telomerase activity.
- Certain cancer cells: Many cancer cells reactivate telomerase, which contributes to their uncontrolled growth and immortality.
However, most somatic cells, including certain liver cells, do not exhibit significant telomerase activity. While some liver cells might show low levels of telomerase activity during regeneration, it is not generally active in normal, differentiated liver cells.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 48
Incorrect
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Which statement describes endogenous transmission the best?
Your Answer:
Correct Answer: Commensal flora that gain access to an inappropriate area
Explanation:All answers A, B, C, and D are examples of exogenous infections. Endogenous infection is an infection by organisms that normally reside in the body but have previously been dormant.
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This question is part of the following fields:
- Infectious Diseases
- Medicine
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Question 49
Incorrect
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Where does secretin work in the pancreas?
Your Answer:
Correct Answer: Pancreatic ducts
Explanation:Secretin, a hormone produced by the duodenal S cells in response to the stomach chyme containing high hydrogen atom concentration (high acidity), is released into the blood stream; upon return to the digestive tract, secretion decreases gastric emptying, increases secretion of the pancreatic ductal cells, as well as stimulating pancreatic acinar cells to release their zymogenic juice.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 50
Incorrect
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Which of the following are responsible for the 4th heart sound?
Your Answer:
Correct Answer: Ventricular hypertrophy
Explanation:The fourth heart sound is not normally audible in a normal adult. It occurs as a consequence of ventricular hypertrophy. It is caused by filling of the ventricle in atrial systole.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 51
Incorrect
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When the heart rate is increased (to pathological levels) which of the following is correct when comparing the duration of diastole to systole?
Your Answer:
Correct Answer: It is shortened to a greater degree
Explanation:The duration of systole is more fixed than the duration of diastole. When the heart rate increases the timing of the systole remains more or less the same however diastole decreases.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 52
Incorrect
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A 43 year old female presents with an array of symptoms including weakness, lethargy, dysphagia, dry mouth, gritty sensation in her eyes and increased photosensitivity. In order to confirm the suspected diagnosis, which of the following tests should be performed?
Your Answer:
Correct Answer: Labial gland biopsy
Explanation:To confirm the diagnosis, especially in patients with negative anti-Ro or anti-La antibodies, labial gland biopsy is done. In performing a labial biopsy, the surgeon typically makes a shallow 1/2 inch wide incision on either side of the inner lip after numbing the area with a local anaesthetic. Schirmer’s test determines whether the eye produces enough tears to keep it moist. This test can be done for ocular symptoms of Sjogren syndrome but is of no diagnostic importance as it can be positive with many other diseases.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 53
Incorrect
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What is the mechanism of action of sildenafil citrate?
Your Answer:
Correct 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 54
Incorrect
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What is the function of migrating motor complex
Your Answer:
Correct Answer: Clears the gut of luminal contents in preparation of the next meal
Explanation:Migrating motor complexes (MMC) are waves of electrical activity that sweep through the intestines in a regular cycle during fasting. These motor complexes trigger peristaltic waves, which facilitate transportation of indigestible substances such as bone, fiber, and foreign bodies from the stomach, through the small intestine, past the ileocecal sphincter, and into the colon. The MMC occurs every 90–120 minutes during the interdigestive phase (between meals), and is responsible for the rumbling experienced when hungry. It also serves to transport bacteria from the small intestine to the large intestine, and to inhibit the migration of colonic bacteria into the terminal ileum.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 55
Incorrect
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A 31 year old female complains of bilateral proximal muscle weakness. There is marked blanching of fingers especially in response to cold weather. Lab results are as follows: Anti Jo-1: positive ANA: positiveCK: 2000 U/LESR: 60mm/hrEMG: myopathic changesPresence of which of the following signifies the worst prognosis?
Your Answer:
Correct Answer: Interstitial lung disease
Explanation:Polymyositis is an inflammatory disorder causing symmetrical, proximal muscle weakness. It is thought to be a T-cell mediated cytotoxic process directed against muscle fibres. It may be idiopathic or associated with connective tissue disorders. It may also be associated with malignancy for example small cell lung carcinoma.Dermatomyositis is a variant of the disease where skin manifestations are prominent, for example a purple (heliotrope) rash on the cheeks and eyelids.It typically affects middle-aged, female: male 3:1. Features include proximal muscle weakness +/- tenderness, Raynaud’s phenomenon, respiratory muscle weakness, interstitial lung disease: e.g. fibrosing alveolitis or organising pneumonia, dysphagia, dysphonia. Investigations: elevated creatine kinase, other muscle enzymes (lactate dehydrogenase (LD), aldolase, AST and ALT) are also elevated in 85-95% of patients, EMG, muscle biopsy. Anti-Jo-1 antibodies are seen in pattern of disease associated with lung involvement, Raynaud’s and fever. Interstitial lung disease plays a major role in morbidity and mortality in patients with polymyositis and is considered a major risk factor for premature death in patients with myositis.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 56
Incorrect
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A 32 year old female is diagnosed with SLE based on her complaints of polyarthralgia, mouth ulcers and ANA positivity. Labs reveal normal urinalysis, urea and electrolytes. ESR is 90mm in the first hour. How will you manage this patient?
Your Answer:
Correct Answer: Hydroxychloroquine 200 mg/day
Explanation:Hydroxychloroquine is used in the management of SLE as it prevents disease progression and has relatively mild side effects, for instance headache, nausea etc. Its use reduces the usage of corticosteroids. It is particularly effective when the disease is less severe and there is no organ involvement. Cyclophosphamide and prednisolone are indicated in cases of renal, neurological and lung involvement.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 57
Incorrect
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Which mechanism of action does Penicillin use?
Your Answer:
Correct 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 58
Incorrect
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Which of the following is a product of D cells
Your Answer:
Correct Answer: Somatostatin
Explanation:Somatostatin is secreted by D cells, HCL and intrinsic factor secreted by parietal cells. Trefoil peptides are secreted by mucus secreting goblet cells and gastrin releasing peptide (grp) by post-ganglionic fibers of the vagus nerve (which innervate the G cells of the stomach).
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 59
Incorrect
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Which of the following statements is not true about mitochondrial chromosomes?
Your Answer:
Correct Answer: Mitochondrial chromosomes play no role in the transmission of disease from generation to generation.
Explanation:All the above mentioned statements are true except that mitochondrial DNA is passed from the mother to the child. If the child inherits the defective mitochondrial gene it will manifest some form of the disease. Commonly inherited diseases related to mitochondrial abnormality are Leber hereditary optic neuropathy and myoclonic epilepsy with ragged red fibers (MERRF).
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This question is part of the following fields:
- Genetics
- Medicine
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Question 60
Incorrect
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A 48-year-old male with a history of bipolar disorder presents with acute confusion. In-transit to hospital he had a generalized seizure which terminated spontaneously after around 30 seconds. On arrival to the emergency department, his GCS is 14/15 and he is noted to have a coarse tremor. Suspecting a diagnosis of lithium toxicity, intravenous access is obtained, a blood sample was drawn for investigations and a saline infusion is started. The blood investigations revealed:Lithium level: 4.2 mmol/lNa+: 136 mmol/lK+: 4.6 mmol/lUrea: 8.1 mmol/lCreatinine: 99 µmol/lBicarbonate: 18 mmol/lWhat is the most appropriate management for the patient?
Your Answer:
Correct Answer: Arrange haemodialysis
Explanation:The presentation of the patient is typical of chronic lithium toxicity (due to the presence of mainly neurological manifestations). Additional to the blood investigations mentioned, urine analysis, electrolyte levels, and renal function should also be performed. A low urine Anion gap and a low urine specific gravity are highly suggestive of lithium toxicity.ECG obtained in this patient is likely to show: nonspecific, diffuse ST segment depression with T wave inversion.Acute lithium toxicity presents with more GI manifestations while, the clinical features of chronic lithium toxicity are mainly neurological and can include:Coarse tremors (fine tremors are seen in therapeutic levels), hyperreflexia, acute confusion, seizures, and coma.The management of lithium toxicity is as follows:Immediate GI decontamination with gastric lavage (in case of acute intoxication)Saline Administrations: the goal of saline administration is to restore GFR, normalize urine output and enhance lithium clearance.Haemodialysis remains the mainstay treatment for lithium toxicity as lithium is readily dialyzed because of water solubility, low volume of distribution, and lack of protein binding.The Extracorporeal Treatments in Poisoning Workgroup (EXTRIP Workgroup) recommendations for dialysis (extracorporeal treatment) in lithium toxicity include:• Impaired kidney function and lithium levels > 4.0 mEq/L• Decreased consciousness, seizures, or life-threatening dysrhythmias, regardless of lithium levels• Levels are > 5.0 mEq/L, significant confusion is noted, or the expected time to reduce levels to < 1.0 mEq/L is more than 36 hoursAs post-dialysis rebound elevations in lithium levels have been documented, continuous veno-venous hemofiltration (CVVH) has been advocated.
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This question is part of the following fields:
- Medicine
- Pharmacology
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