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Question 1
Correct
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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: 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 2
Incorrect
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Which of the following has the shortest duration:
Your Answer: Atrial diastole
Correct Answer: Atrial systole
Explanation:Atrial systole: 0.1s
Atrial diastole: around 0.4s
Ventricular diastole: 0.4-0.53s
Ventricular systole: 0.27s
PR interval: 0.12-0.2 s
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 3
Incorrect
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A 27-year-old male is admitted after drinking engine coolant in an apparent suicide attempt. Lab investigations reveal:
- pH 7.1 (7.36-7.44)
- pO2 15.3 kPa (11.3-12.6)
- pCO2 3.2 kPa (4.7-6.0)
- Standard bicarbonate 2.2 mmol/L (20-28)
- Serum calcium 1.82 mmol/L (2.2-2.6)
Your Answer: Gastric lavage
Correct Answer: Fomepizole infusion
Explanation:The patient’s symptoms and lab results are indicative of ethylene glycol poisoning, commonly found in engine coolant. Ethylene glycol is metabolized to toxic metabolites, including glycolic acid and oxalic acid, which can cause metabolic acidosis (evidenced by the low pH and low bicarbonate levels) and can bind calcium, leading to hypocalcemia.
Fomepizole is an antidote that inhibits alcohol dehydrogenase, the enzyme that converts ethylene glycol into its toxic metabolites. This prevents further formation of the harmful substances, allowing time for the ethylene glycol to be excreted unchanged in the urine.
While haemodialysis is also an important treatment for severe ethylene glycol poisoning, especially in cases of significant acidosis or renal failure, the immediate administration of fomepizole is the most urgent intervention to prevent further toxicity. Haemodialysis can be considered if the patient does not respond adequately to fomepizole or if there are signs of severe toxicity.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 4
Incorrect
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Which of the following substances is involved in the respiratory burst by the neutrophil?
Your Answer: Myeloperoxidase converts br/i/cl to acids
Correct Answer: NADPh oxidase
Explanation:The respiratory burst is a rapid release of reactive oxygen species (ROS) from neutrophils and other phagocytes. This process is crucial for the destruction of pathogens. The key components and enzymes involved in the respiratory burst include:
- NADPH oxidase: This enzyme complex plays a central role in the respiratory burst by converting oxygen (O2) into superoxide anion (O2•-), a reactive oxygen species. This is the initial step in the production of various ROS.
- Superoxide dismutase (SOD): This enzyme converts superoxide anion (O2•-) into hydrogen peroxide (H2O2). While SOD is involved in the pathway, the respiratory burst is initiated by NADPH oxidase.
- Myeloperoxidase (MPO): This enzyme uses hydrogen peroxide (H2O2) to produce hypochlorous acid (HOCl) from chloride ions (Cl-), which is a potent antimicrobial agent. Myeloperoxidase also produces other reactive species using halide ions.
- Catalase: This enzyme degrades hydrogen peroxide (H2O2) into water (H2O) and oxygen (O2). While catalase helps to protect the cell from oxidative damage by breaking down H2O2, it is not involved in the generation of ROS during the respiratory burst.
- Adenylate cyclase: This enzyme is involved in the production of cyclic AMP (cAMP) from ATP and is not directly related to the respiratory burst.
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This question is part of the following fields:
- Immunology
- Medicine
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Question 5
Correct
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Absorption of protein antigens i.e. bacterial and viral proteins takes place in the:
Your Answer: Microfold cells (m cells) of the intestine
Explanation:M cells are specialized epithelial cells. They have a high capacity of transcytosis of microorganisms and macromolecules. They rapidly uptake antigens and present them to immune cells associated with the gut. In contrast to absorptive enterocytes, M cells do not exert direct defence mechanisms to antigens and pathogens in the intestinal cavity. Crypts of Lieberkühn are located mainly in the small intestine and large intestine and the main function is to replenish epithelial cells and to secrete intestinal enzymatic juice as well as mucous. Brunner’s glands empty into intestinal glands and their main function is to secrete mucin and to form a protective mucus layer on the duodenal epithelial cells to protect it from acidic chyme coming from the stomach. Islets of Langerhans are located in the pancreas and secrets insulin mainly. Mucosa associated lymphoid tissue plays a role in inducing immune response after presentation of antigens.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 6
Correct
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The motor speech area (Brocas Area) is:
Your Answer: Brodmann area 44
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 7
Correct
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Where is the most erythropoietin produced?
Your 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 8
Incorrect
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What is the blood supply to the liver?
Your Answer: Portal vein only
Correct Answer: Hepatic artery and hepatic portal vein
Explanation:The liver receives a dual blood supply from the hepatic portal vein and hepatic arteries. The hepatic portal vein delivers approximately 75% of the liver’s blood supply, and carries venous blood drained from the spleen, gastrointestinal tract, and its associated organs. The hepatic arteries supply arterial blood to the liver, accounting for the remaining quarter of its blood flow. Oxygen is provided from both sources; approximately half of the liver’s oxygen demand is met by the hepatic portal vein, and half is met by the hepatic arteries
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This question is part of the following fields:
- Hepatobiliary
- Medicine
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Question 9
Correct
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A 23 year old man presents with a painful right elbow and left Achilles tendon. He also gives history of dysuria, fever and conjunctivitis. Examination reveals macules and pustules on his hands. He has returned from a trip to Far East 3 weeks ago and admits to having unprotected sex. Which of the following is the most likely diagnosis?
Your Answer: Reactive arthritis
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. Other STDs including HIV, syphilis have different presentations. Psoriatic arthritis is not commonly associated with urethritis and conjunctivitis.
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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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If UA = concentration of A in urine, V = urine flow per unit time, and PA = arterial plasma level of A, renal clearance of A is equal to?
Your Answer: PA/(UA x V)
Correct Answer: (UA x V)/PA
Explanation:Renal clearance = [Urine concentration (UA) x Urine flow (V)]/[Plasma concentration (PA)]
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This question is part of the following fields:
- Medicine
- Renal
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Question 11
Incorrect
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What is the effect of vasopressin on the kidney?
Your Answer: Decrease collecting duct permeability to water
Correct Answer: Increase collecting duct permeability to water
Explanation:Vasopressin, also known as antidiuretic hormone or ADH, which increases water reabsorption in the kidney’s collecting ducts. It works by increasing water permeability in the collecting ducts and distal convoluted tubules. It induces the exocytosis of AQP-CD-laden vesicles, transferring water channels from intracellular vesicles to the apical plasma membrane, therefore allowing more water to be reabsorbed from the urine in the collecting ducts to the blood.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 12
Incorrect
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Which of the following are true with regard to autosomal recessive disorders:
Your Answer: These disorders only manifest themselves where an individual is homozygous for the disease allele
Correct Answer: All are true
Explanation:All are true for autosomal recessive disorders.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 13
Incorrect
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Which of the following drugs have the best gram positive cover?
Your Answer: Cephalosporin
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 14
Incorrect
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The complex twisting and folding of peptide chains describes which order of protein structure?
Your Answer: Functional unit
Correct Answer: Secondary structure
Explanation:Secondary Structure refers to the coiling or folding of a polypeptide chain that gives the protein its 3-D shape. There are two types of secondary structures: the alpha (α) helix and the beta (β) pleated sheet.
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This question is part of the following fields:
- Medicine
- Metabolism
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Question 15
Incorrect
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Regarding the cardiac muscle striations as viewed under the microscope, which areas are dark?
Your Answer: H band and i band
Correct Answer: A band and z line
Explanation:Dark bands: a, h. Dark line: z. Clear band: i, m
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 16
Incorrect
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Question 17
Incorrect
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Bone marrow barrier is important to:
Your Answer: All of the above
Correct Answer: Allow mature red blood cells to pass into circulation
Explanation:The blood vessels of the bone marrow constitute a barrier, inhibiting immature blood cells from leaving the marrow. Only mature blood cells contain the membrane proteins, such as aquaporin and glycophorin, that are required to attach to and pass the blood vessel endothelium.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 18
Correct
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A 53 year old female, longstanding case of rheumatoid arthritis comes for a review. Which of the following features are commonly associated with her condition?
Your Answer: Proximal interphalangeal joint involvement in the hands
Explanation:Rheumatoid arthritis is a polyarthritis that results in symmetrical pain and swelling of the affected joints (also at rest). It particularly affects the metacarpophalangeal joints (MCPJs) and proximal interphalangeal joints (PIPJs), not the distal interphalangeal joints (DIPs). Ulcerative colitis and IBD are associated with seronegative arthritides, not RA. The condition can also cause various extra-articular manifestations such as ocular symptoms, rheumatoid nodules and pulmonary fibrosis. Scleritis, episcleritis and keratoconjunctivitis sicca are more common than uveitis. Early intervention with disease-modifying antirheumatic drugs (DMARDs) plays a decisive role in successful treatment.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 19
Correct
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Question 20
Incorrect
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Nucleic acids are split into nucleotides in the:
Your Answer: Spleen
Correct Answer: Intestine
Explanation:The pancreas is the major source for all the digestive enzymes including nucleases which split nucleic acids into nucleotides primarily in the small intestine.
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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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Sequence of events in formation of speech are:
Your Answer: Insula---arcuate fasciculus---Wernicke's area---broca’s area---motor cortex---speech
Correct Answer: Wernicke’s area---arcuate fasciculus---broca’s area---insula---motor cortex---speech
Explanation:Wernicke’s area is located in the categorical hemisphere or left hemisphere in about 95% of right handed individuals and 60% of left handed individuals. It is involved in the comprehension or understanding of written and spoken language. In contrast Broca’s area is involved in production of language. Firstly, the language is accessed in the Wernicke’s area and these words are sent via the arcuate fasciculus to the Broca’s area, where instructions for articulation is generated. This is then sent from Broca’s are to the motor cortex for the articulation.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 22
Incorrect
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Stroke volume in a average sized man lying in supine position is about?
Your Answer: 85 ml
Correct Answer: 70 ml
Explanation:The stroke volume of an average sized man who is lying is the supine position is about 70 ml.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 23
Incorrect
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Which of the following skin conditions is not associated with diabetes mellitus?
Your Answer: Scleroderma
Correct Answer: Sweet's syndrome
Explanation:Diabetic dermadromes constitute a group of cutaneous conditions commonly seen in people with diabetes with longstanding disease. Conditions included in this group are:- Acral dry gangrene- Carotenosis- Diabetic dermopathy- Diabetic bulla- Diabetic cheiroarthropathy- Malum perforans- Necrobiosis lipoidica- Limited joint mobility- Scleroderma- Waxy skin is observed in roughly 50%. Sweet’s syndrome is also known as acute febrile neutrophilic dermatosis has a strong association with acute myeloid leukaemia. It is not associated with diabetes mellitus.
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This question is part of the following fields:
- Dermatology
- Medicine
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Question 24
Correct
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Glucose transport in the brain is mediated by:
Your 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 25
Incorrect
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In the jugular venous pressure wave…
Your Answer: Giant v wave occurs in tricuspid stenosis
Correct Answer: Consists of 3 peaks and 2 troughs
Explanation:The jugular venous pressure (JVP, sometimes referred to as jugular venous pulse) is the indirectly observed pressure over the venous system via visualization of the internal jugular vein. It can be useful in the differentiation of different forms of heart and lung disease. Classically three upward deflections (peaks) and two downward deflections (troughs) have been described:The upward deflections are the a (atrial contraction), c (ventricular contraction and resulting bulging of tricuspid into the right atrium during isovolumetric systole) and v = venous filling.The downward deflections of the wave are the x (the atrium relaxes and the tricuspid valve moves downward) and the y descent (filling of ventricle after tricuspid opening).
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 26
Incorrect
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Live active or attenuated vaccines:
Your Answer: Boosting is often required
Correct Answer: Side effect may be egg hypersensitivity
Explanation:Live attenuated vaccines consist of a weakened form of the virus itself and have both advantages and disadvantages. Although they can exert an excellent immune response, potential risks exist. One such concern is the risk of reversion to a more virulent strain of virus. They are easily damaged or destroyed by heat and light, making it even more important that they be stored and refrigerated with care. Live vaccines are not given to immunocompromised persons. A few live vaccines against viruses include: oral polio, measles, mumps, rubella, rota virus and yellow fever. Eggs are used to produce Measles- mumps- rubella vaccine (MMR) and thus hypersensitivity may occur.
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This question is part of the following fields:
- Infectious Diseases
- Medicine
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Question 27
Incorrect
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During which phase of the cell cycle does DNA synthesis occur?
Your Answer: G0
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
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This question is part of the following fields:
- Genetics
- Medicine
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Question 28
Correct
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A 50-year-old man is admitted with nausea and excessive drowsiness after taking an antihistamine tablet with grapefruit juice. Which of the following liver enzyme systems is affected by grapefruit juice causing the given side effect?
Your Answer: Cytochrome p450 3A4
Explanation:The cytochrome p450 3A4 enzyme system in the liver is affected by grapefruit juice. Patients taking antihistamines should be advised to avoid drinking grapefruit juice. This is because constituents of grapefruit juice such as naringin and bergamottin inhibit CYP3A4 in the liver, particularly at high doses, leading to decreased drug elimination via hepatic metabolism and can increase potential drug toxicities. Inhibition of this enzyme system leads to reduced metabolism of antihistamines leading to an increased incidence of side effects like excessive drowsiness and nausea as in this patient.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 29
Incorrect
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The Plateau phase in myocyte action potentials does all of the following except:
Your Answer: It is a refractory phase
Correct Answer: It allows early reactivation of the myocytes
Explanation:The presence of the plateau in the action potential causes ventricular contraction to last as much as 15 times longer in cardiac muscle as in skeletal muscle. The plateau phase which follows is unique to myocytes and results from a small, but sustained inward calcium current through L-type calcium channels lasting 200-400 ms. This calcium influx is caused by a combined increase in permeability of the cell and especially the sarcolemmal membranes to calcium. This plateau (refractory) phase prevents early reactivation of the myocytes and directly determines the strength of contraction.
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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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Which statement is correct about the clinical state of methemoglobinemia?
Your Answer: Is present when the iron in the haemoglobin is in the Fe2+ state
Correct Answer: May arise due to a hereditary deficiency of NADH.
Explanation:Methaemoglobin is a form of haemoglobin that contains ferric [Fe3+] iron and has a decreased ability to bind oxygen. Spontaneously formed methaemoglobin is normally reduced by protective enzyme systems, e.g., NADH methaemoglobin reductase, hence a deficiency of NADH may result in increased levels of methaemoglobin
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This question is part of the following fields:
- Haematology
- Medicine
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SESSION STATS - PERFORMANCE PER SPECIALTY
