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Question 1
Correct
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Regarding propofol, which of the following statements is INCORRECT:
Your Answer: A lower induction dose of propofol is required in children.
Explanation:Elderly patients have a reduced volume of distribution and slower clearance of the drug. They are therefore more sensitive to the effects of propofol and the drug wears off more slowly. They need less of the drug, which should be injected slowly, monitoring its effect on the patient. The opposite is true in children, who need larger doses of propofol. This is particularly so in children under three years of age. Propofol is not recommended for induction of anaesthesia in children under one month of age or for maintenance of anaesthesia in children under three years old.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 2
Correct
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Which statement regarding skeletal muscle is true?
Your Answer: Myosin is the major constituent of the thick filament
Explanation:Myosin is the major constituent of the thick filament. Actin is the major constituent of the THIN filament. Thin filaments consist of actin, tropomyosin and troponin in the ratio 7:1:1.
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 3
Correct
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Dehydration causes a significant increase in the amount of this hormone?
Your Answer: Antidiuretic hormone
Explanation:Antidiuretic hormone induces the kidneys to release less water, resulting in reduced urine production. In the case of dehydration, ADH levels rise, resulting in a considerable decrease in urine output as well as an increase in plasma protein, blood Hct, and serum osmolality.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 4
Correct
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What is the primary route of transmission of Norovirus?
Your Answer: Oral-faecal route
Explanation:Norovirus is spread primarily by faecal-oral contact, but it can also be spread through contact with an infected person, ingestion of contaminated food or water, or contact with contaminated surfaces or items.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 5
Correct
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A patient complains of stomach ache. You see a midline scar in the epigastric area when you examine the abdomen. Upon further interrogation, the patient reveals that she had a subtotal gastrectomy for recurring stomach ulcers several years ago. The stomach mucosa secretes a variety of vital compounds, and her ability to secrete some of these molecules has been harmed as a result of his surgery.The stomach G-cells are responsible for which of the following?Â
Your Answer: Secretion of gastrin
Explanation:G-cells are a type of cell found in the stomach’s pyloric antrum, duodenum, and pancreas. The secretion of the peptide hormone gastrin is their major function.The table below summarizes the many cell types found in the stomach, as well as the substances secreted by each cell type and the function of the secretion:Cell type/ Substance secreted/ Function of secretionParietal cells/ Hydrochloric acid/ Kills microbes and activates pepsinogenParietal cells/ Intrinsic factor/Binds to vitamin B12 and facilitates its absorptionChief cells/ Pepsinogen/ Protein digestionChief cells/ Gastric lipase/ Fat digestionG-cells/ Gastrin/ Stimulates gastric acid secretionEnterochromaffin-like cells (ECL cells) /Histamine/ Stimulates gastric acid secretionMucous-neck cells/ Mucous and bicarbonate/ Protects stomach epithelium from acidD-cells/ Somatostatin/ Inhibits gastric acid secretion
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This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 6
Incorrect
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Platelet alpha granules release which of the following?
Your Answer: Thromboxane A2
Correct Answer: Von Willebrand factor (VWF)
Explanation:There are three types of storage granules contained in platelets. These are dense granules which contain the following:-ATP -ADP -serotonin and calcium alpha granules containing clotting factors-von Willebrand factor (VWF)-platelet-derived growth factor (PDGF)- other proteins lysosomes containing hydrolytic enzymes.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 7
Correct
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Carbamazepine is contraindicated in which of the following:
Your Answer: Atrioventricular block
Explanation:Carbamazepine is contraindicated in:- People with known hypersensitivity to carbamazepine or structurally related drugs- People with atrioventricular block (may suppress AV conduction and ventricular automaticity)- People with a history of bone marrow depression (risk of agranulocytosis and aplastic anaemia)- People with a history of acute porphyrias- People taking a monoamine oxidase inhibitor (risk of serotonin syndrome)
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 8
Correct
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A 38-year-old man returns from an overseas business trip with a fever and a headache. Following investigations a diagnosis of Plasmodium falciparum malaria is made.Which of the following statements regarding Plasmodium falciparum malaria is true? Select ONE answer only.
Your Answer: There may be a continuous fever
Explanation:Plasmodium falciparum malaria is transmitted by female of the Anopheles genus of mosquito. The Aedes genus is responsible for transmitting diseases such as dengue fever and yellow fever.Plasmodium falciparumis found globally but is mainly found in sub-Saharan Africa.The incubation period of Plasmodium falciparum malaria is 7-14 days.Sporozoites invade hepatocytes. Within the hepatocyte asexual reproduction occurs producing merozoites, which are released into the blood stream and invade the red blood cells of the host.Artesunate is the drug treatment of choice for Plasmodium falciparum malaria. Quinine can still be used where artesunate is not available. Often combination therapy with drugs such as doxycycline or fansidar is also required.The classic symptom of malaria is the malarial paroxysm, a cyclical occurrence of a cold phase, where the patient experiences intense chills, a hot stage, where the patient feels extremely hot and finally a sweating stage, where the fever declines and the patient sweats profusely. There may also, however, be a continuous fever.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 9
Incorrect
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Which of the following statements is correct with regards to Klebsiella spp?
Your Answer: They are obligate anaerobes.
Correct Answer: They are typically associated with nosocomial infection.
Explanation:Klebsiella is a type of bacteria commonly found in nature. In humans, the bacteria are often present in parts of the digestive tract and respiratory flora, where they do not generally cause problems. They are anaerobic Gram-negative rods. They are usually opportunistic pathogens which cause nosocomial infections, the most common ones being pneumonia and UTI.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 10
Correct
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Which of the following is a well recognised adverse effect of prochlorperazine:
Your Answer: Acute dystonic reaction
Explanation:Adverse actions include anticholinergic effects such as drowsiness, dry mouth, and blurred vision, extrapyramidal effects, and postural hypotension. Phenothiazines can all induce acute dystonic reactions such as facial and skeletal muscle spasms and oculogyric crises; children (especially girls, young women, and those under 10 kg) are particularly susceptible.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 11
Correct
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Regarding the trachea, which of the following statements is INCORRECT:
Your Answer: A cricothyrotomy involves making an opening in the neck inferior to the cricoid cartilage.
Explanation:A cricothyrotomy involves making an opening in the median cricothyroid ligament (the medial part of the cricothyroid membrane), between the cricoid cartilage below and the thyroid cartilage above.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 12
Incorrect
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Which of the following nerves is responsible for the symptoms of a patient with history of recurrent herpes simplex outbreaks on his face and presents with ophthalmic herpes zoster and a painful vesicle on the tip of his nose?
Your Answer: Infraorbital nerve
Correct Answer: Nasociliary nerve
Explanation:Hutchinson sign relates to involvement of the tip of the nose from facial herpes zoster. It implies involvement of the external nasal branch of the nasociliary nerve which is a branch of the ophthalmic division of the trigeminal nerve. The nasociliary branch of the trigeminal nerve innervates the apex and lateral aspect of the nose, as well as the cornea. Therefore, lesions on the side or tip of the nose should raise suspicion of ocular involvement.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 13
Correct
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If the ejection fraction increases, there will be a decrease in:
Your Answer: End-systolic volume
Explanation:An increase in ejection fraction means that a higher fraction of the end-diastolic volume is ejected in the stroke volume (e.g. because of the administration of a positive inotropic agent). When this situation occurs, the volume remaining in the ventricle after systole, the end-systolic volume, will be reduced. Cardiac output, stroke volume, and mean arterial pressure will be increased.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 14
Correct
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Which statement concerning aerosol transmission is true?
Your Answer: They can be spread via ventilation systems in hospitals
Explanation:Aerosols are airborne particles less than 5 µm in size containing infective organisms. They usually cause infection of both the upper and/or lower respiratory tract.The organisms can remain suspended in the air for long periods and also survive outside the body. They can be transmitted through the ventilation systems and can spread over great distances. Some examples of organisms transmitted by the aerosol route include: Varicella zoster virus, Mycobacterium tuberculosis and measles virus
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 15
Incorrect
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Which of the following is NOT an adverse effect associated with warfarin therapy:
Your Answer: Pancreatitis
Correct Answer: Neutropenia
Explanation:Adverse effects of warfarin:The most common adverse effect of warfarin is bleedingOther common adverse effects of warfarin include nausea, vomiting, diarrhoea, jaundice, hepatic dysfunction, pancreatitis, pyrexia, alopecia, purpura, and rashSkin necrosis is a rare but serious adverse effect of warfarin; treatment with warfarin should be stopped if warfarin related skin necrosis is suspectedCalciphylaxis is a rare, but a very serious condition that causes vascular calcification and cutaneous necrosis
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 16
Correct
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A 25 year old woman who is a known diabetic is brought to the ED with diabetic ketoacidosis. She promptly received an insulin infusion. Which of the following are expected to increase upon infusion of insulin?
Your Answer: Blood pH
Explanation:Ketoacidosis is characterized by hyperglycaemia, glycosuria, hyperkalaemia, and metabolic acidosis with respiratory compensation. An insulin infusion would be able to address these by lowering blood glucose through increased insulin-mediated cellular uptake, lowering urine glucose concentration as cellular glucose uptake is increased, decreasing K+ in her blood by shifting it into cells, and increasing blood ph by addressing the metabolic acidosis. The metabolic acidosis is addressed by the reduction of ketoacids production thereby returning her blood ph to normal and reducing the need for compensatory hyperventilation.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 17
Correct
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Regarding the UK routine childhood immunisation schedule which of the following vaccines is NOT given at 2 months:
Your Answer: Meningococcal group C
Explanation:At 2 months the following vaccines are given: Diphtheria, tetanus, pertussis, polio, Haemophilus influenzae type b (Hib) and hepatitis BRotavirus gastroenteritisMeningococcal group B
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This question is part of the following fields:
- Immunoglobulins And Vaccines
- Pharmacology
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Question 18
Correct
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All of the following are physiological effects of thyroid hormones except:
Your Answer: Increased glycogenesis
Explanation:Thyroid hormones have multiple physiological effects on the body. These include:1. Heat production (thermogenesis)2. Increased basal metabolic rate3. Metabolic effects: (a) Increase in protein turnover (both synthesis and degradation are increased, although overall effect is catabolic)(b) Increase in lipolysis(c)Increase in glycogenolysis and gluconeogenesis4. Enhanced catecholamine effect – Increase in heart rate, stroke volume and thus cardiac output5. Important role in growth and development
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 19
Incorrect
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For the treatment of his atrial fibrillation, a 67-year-old man is about to begin taking warfarin. He also takes a number of other medications.Which of the following medications will prevent warfarin from working?
Your Answer: Clarithromycin
Correct Answer: Phenytoin
Explanation:Many medications, including warfarin, require cytochrome P450 enzymes for their metabolism. When co-prescribing cytochrome p450 enzyme inducers and inhibitors with warfarin, it’s critical to be cautious.Inhibitors of the cytochrome p450 enzyme inhibit the effects of warfarin, resulting in a lower INR. To remember the most commonly encountered cytochrome p450 enzyme inducers, use the mnemonic PC BRASS:P– PhenytoinC– CarbamazepineB– BarbituratesR– RifampicinA– Alcohol (chronic ingestion)S– SulphonylureasS– Smoking
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 20
Correct
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Regarding gas exchange at the alveolar-capillary membrane, which of the following statements is CORRECT:
Your Answer: The rate of diffusion in lungs can be estimated by measuring the diffusing capacity of the lungs for carbon monoxide.
Explanation:Gas exchange between alveolar air and blood in the pulmonary capillaries takes place by diffusion across the alveolar-capillary membrane. Diffusion occurs from an area of high partial pressure to an area of low partial pressure, thus the driving force for diffusion is the alveolar-capillary partial pressure gradient. Diffusion occurs across a membrane and is therefore governed by Fick’s law. Although CO2is larger than O2, it is is much more soluble and diffuses 20 times more rapidly. The diffusing capacity for oxygen (DLO2) cannot be measured directly but the rate of diffusion in the lungs can be estimated by measuring the diffusing capacity of the lungs for carbon monoxide (DLCO).
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 21
Incorrect
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The second generation antihistamine, cetirizine is a less-sedating antihistamine than the older antihistamine, chlorphenamine because:
Your Answer: It is selective for H1-receptors.
Correct Answer: It is less lipid-soluble so less able to cross the blood brain barrier.
Explanation:All older antihistamines such as chlorphenamine cause sedation. The newer antihistamines e.g. cetirizine cause less sedation and psychomotor impairment than the older antihistamines because they are much less lipid soluble and penetrate the blood brain barrier only to a slight extent.
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 22
Correct
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A 30-year-old male presents with easy bruising and bleeding gums, feeling very tired lately, and recurrent chest infections over the past few months. He had glandular fever approximately 6 months ago and feels that his symptoms started after that. His full blood count today is as follows: Hb 6.3 g/dl (11.5-14 g/dl) MCV 90 fl (80-100 fl) WCC 2.0 x 10 9 /l (4-11 x 10 9 /l) Platelets 15 x 10 9 /l (150-450 x 10 9 /l)The SINGLE most likely diagnosis is?
Your Answer: Aplastic anaemia
Explanation:Aplastic anaemia is a life-threatening failure of haemopoiesis characterised by pancytopenia and hypocellular bone marrow. It is rare and patients present with features of recurrent infections secondary to (leukocytopenia), increased bleeding tendency (secondary to thrombocytopenia) and anaemia. In aplastic anaemia, there is damage to the bone marrow and the haematopoietic stems cells leading to pancytopenia.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 23
Correct
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Question 24
Incorrect
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A 32-year-old asthmatic patient on theophylline as part of her asthma management presents to the Emergency Department with an unrelated medical condition.Which of these drugs should be avoided?
Your Answer: Metronidazole
Correct Answer: Clarithromycin
Explanation:Macrolide antibiotics (e.g. clarithromycin and erythromycin) are cytochrome P450 enzyme inhibitors. They increase blood levels of theophylline leading to hypokalaemia, and potentially increasing the risk of Torsades de pointes when they are prescribed together. Co-prescription with theophylline should be avoided.Factors that enhance theophylline clearance include cigarette smoking, carbamazepine, phenobarbital, phenytoin, primidone, and rifampin. Medications that inhibit clearance include ethanol, ciprofloxacin, erythromycin, verapamil, propranolol, ticlopidine, tacrine, allopurinol, and cimetidine.
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This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 25
Correct
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An 80-year-old patient with a history of chronic heart failure presents to you. Examination reveals widespread oedema.Which statement about plasma oncotic pressure (Ï€ p ) is true?
Your Answer: The influence of π p on fluid movement is negligible if the capillary reflection co-efficient is 0.1
Explanation:Plasma oncotic pressure (πp) is typically 25-30 mmHg. 70% of π p is generated by albumin so Hypoalbuminemia will decrease π pThe osmotic power of albumin is enhanced by the Gibbs-Donnan effect.The influence of π p on fluid movement is negligible if the capillary reflection coefficient is 0.1. Another way of saying a vessel is highly permeable is saying the reflection coefficient is close to 0.
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This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
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Question 26
Correct
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A 6-year-old female is brought to the Ophthalmology Clinic by her mother with the complaint of itching, redness, and a watery discharge of the right eye. Past medical history revealed an upper respiratory tract infection one week ago. On examination of the right eye, there is mild erythema of the palpebral conjunctiva and visible follicles seen on eversion of the eyelid, lid oedema, and subconjunctival petechial haemorrhages. The discharge is watery and not purulent. You diagnose her with viral conjunctivitis. According to the current NICE guidelines, which ONE of the following management options would NOT be included for this patient?
Your Answer: The child should be excluded from school until the infection has resolved
Explanation:The NICE guidelines do NOT recommend isolating a patient with viral conjunctivitis from others or skipping school or work. The disease is contagious, but the spread of the disease can be controlled by maintaining good hygiene practices such as:1. frequent hand washing2. use of separate flannels and towels3. Avoid close contact with othersAntibiotic prescriptions are not part of the NICE guidelines for viral conjunctivitis as they will not affect the course of the disease. Most cases of viral conjunctivitis are self-limiting and resolve within one to two weeks.The NICE guidelines recommend that symptoms may be eased with self-care measures such as:1. Bathing/cleaning the eyelids with cotton wool soaked in sterile saline or boiled and cooled water to remove any discharge2. Cool compresses applied gently around the eye area3. Use of lubricating drops or artificial tears
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 27
Incorrect
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You examine a 78-year-old man who has been diagnosed with chronic lymphocytic leukaemia (CLL).What is the MAIN contributory factor in this condition's immunodeficiency?
Your Answer: Lymphopenia
Correct Answer: Hypogammaglobulinemia
Explanation:Immunodeficiency is present in all patients with chronic lymphocytic leukaemia (CLL), though it is often mild and not clinically significant. Infections are the leading cause of death in 25-50 percent of CLL patients, with respiratory tract, skin, and urinary tract infections being the most common.Hypogammaglobulinemia is the most common cause of immunodeficiency in CLL patients, accounting for about 85 percent of all cases.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 28
Correct
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What is the recommended dosing regime for amiodarone in the treatment of a stable regular broad-complex tachycardia:
Your Answer: 300 mg IV over 10 - 60 minutes, followed by an IV infusion of 900 mg over the next 24 hours
Explanation:A ventricular tachycardia (or broad-complex tachycardia of uncertain origin) should be treated with amiodarone 300 mg IV over 10 – 60 min, followed by an infusion of 900 mg over the next 24 hours.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 29
Correct
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Which of the following hormones is dysfunctional in diabetes insipidus:
Your Answer: Antidiuretic hormone
Explanation:Diabetes insipidus (DI) may result from a deficiency of ADH secretion (cranial DI) or from an inappropriate renal response to ADH (nephrogenic DI). As a result, fluid reabsorption at the kidneys is impaired, resulting in large amounts of hypotonic, dilute urine being passed with a profound unquenchable polydipsia.The biochemical hallmarks of DI are:High plasma osmolality (> 295 mOsm/kg)Low urine osmolality (< 300 mOsm/kg)Hypernatraemia (> 145 mmol/L)High urine volume
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 30
Correct
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Which of the following anatomical structures is most likely the cause of oedema and erythema of the arm in a patient who underwent modified radical mastectomy and radiotherapy?
Your Answer: Axillary lymph nodes
Explanation:Arm oedema is one of the sequelae after breast cancer surgery and radiation therapy. Arm oedema in the breast cancer patient is caused by interruption of the axillary lymphatic system by surgery or radiation therapy, which results in the accumulation of fluid in subcutaneous tissue in the arm, with decreased distensibility of tissue around the joints and increased weight of the extremity. Chronic inflammatory changes result in both subcutaneous and lymph vessel fibrosis.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 31
Correct
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In ventricular myocytes, the plateau phase of the action potential comes about through which of the following:
Your Answer: Opening of voltage-gated Ca 2+ channels
Explanation:After the intial upstroke of the action potential, Na+channels and currents rapidly inactivate, but in cardiac myocytes, the initial depolarisation activates voltage-gated Ca2+channels (slow L-type channels, threshold approximately – 45 mV) through which Ca2+floods into the cell. The resulting influx of Ca2+prevents the cell from repolarising and causes a plateau phase, that is maintained for about 250 ms until the L-type channels inactivate. The cardiac AP is thus much longer than that in nerve or skeletal muscle.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 32
Incorrect
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Regarding likelihood ratios, which of the following statements is INCORRECT:
Your Answer: A test with a low negative likelihood ratio is good at increasing certainty about the absence of a disorder.
Correct Answer: Likelihood ratios, like predictive values, are affected by the prevalence of the disease in the population.
Explanation:A likelihood ratio is a measure of the diagnostic value of a test. Likelihood ratios show how many times more likely patients with a disease are to have a particular test result than patients without the disease. Likelihood ratios are more useful than predictive values because they are calculated from sensitivity and specificity and therefore remain constant even when the prevalence of the disorder changes.
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 33
Correct
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A 24-year-old man goes to the emergency department with a fever, headache, and swollen parotid glands that are excruciating. You have a suspicion that it is mumps. Which of the following nerves is causing the discomfort the patient is experiencing:
Your Answer: Auriculotemporal nerve
Explanation:The auriculotemporal nerve is irritated by mumps, which results in significant discomfort due to inflammation and swelling of the parotid gland, as well as the stretching of its capsule. Compression caused by swallowing or chewing exacerbates pain.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 34
Correct
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What kind of function loss do you anticipate in a 22-year-old guy who had a laceration to his arm, resulting in nerve damage in the antecubital fossa?
Your Answer: Opposition of thumb
Explanation:The symptoms of median nerve injury include tingling or numbness in the forearm, thumb, and three adjacent fingers, as well as gripping weakness and the inability to move the thumb across the palm. Because the thenar muscles and the flexor pollicis longus are paralyzed, flexion, abduction, and opposition of the thumb at the MCPJ and IPJ are gone.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 35
Correct
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For which of the following class of drugs can neostigmine be used as a reversal agent?
Your Answer: Non-depolarising muscle relaxants
Explanation:Neostigmine is used specifically for reversal of nondepolarizing (competitive) blockade and is anticholinesterase. It acts within one minute of intravenous injection, and the effects last for 20 to 30 minutes. After this time period, a second dose may then be necessary.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 36
Correct
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A patient suffered from a chest injury while working out in the gym. As a consequence of his injury, his pectoralis minor muscle was damaged.Which of the following statements regarding the pectoralis minor muscle is considered correct?
Your Answer: It stabilises the scapula
Explanation:The pectoralis minor, in comparison to the pectoralis major, is much thinner and triangular in shape and resides below the major. It originates from the margins of the third to fifth ribs adjacent to the costochondral junction. The fibres consequently pass upward and laterally to insert into the medial border and superior surface of the coracoid process. It is crucial in the stabilization of the scapula by pulling it downward and anteriorly against the thoracic wall.Arterial supply to the pectoralis minor also derives from the pectoral branch of the thoracoacromial trunk. Nerve supply of the pectoralis minor is a function of the lateral pectoral nerve and the medial pectoral nerve.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 37
Correct
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Which JVP waveform correlates to atrial systole?
Your Answer: The a wave
Explanation:JVP Waveform in Cardiac Cycle Physiology: a wave Right atrial contraction causes atrial systole (end diastole). the c wave During right isovolumetric ventricular contraction, the tricuspid valve bulges into the right atrium, resulting in isovolumetric contraction (early systole). descent by x Rapid ventricular ejection (mid systole) is caused by a combination of right atrial relaxation, tricuspid valve downward movement during right ventricular contraction, and blood ejection from both ventricles. the v-wave Ventricular ejection and isovolumetric relaxation (late systole) occur as a result of venous return filling the right atrium. y lineage Ventricular filling occurs when the tricuspid valve opens, allowing blood to flow rapidly from the right atrium to the right ventricle.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 38
Correct
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What is the primary function of the mitochondria?
Your Answer: The production of the cell's supply of chemical energy
Explanation:The mitochondria is responsible for the production of the cell’s supply of chemical energy. It does this by using molecular oxygen, sugar and small fatty acid molecules to generate adenosine triphosphate (ATP) by a process ss known as oxidative phosphorylation. An enzyme called ATP synthase is required. Transcription of ribosomal RNA occurs in the nucleolusProduction of messenger RNA occur in the nucleusProduction of lysosome occurs in the Golgi apparatusThe post-translational processing of newly made proteins occurs in the endoplasmic reticulum
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 39
Incorrect
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Excessive gastric acid output is detected in a patient with a history of recurrent stomach ulcers. It's possible that the patient has Zollinger-Ellison syndrome.Which of the following statements about stomach acid is correct?
Your Answer: The hydrogen ion concentration is roughly 1000 times higher than in blood
Correct Answer: The proton pump located in the canalicular membrane is vital to its secretion
Explanation:The stomach produces gastric acid, which is a digesting fluid. The stomach secretes about 2-3 litres every day. It is involved in tissue breakdown, the conversion of pepsinogen to active pepsin, and the creation of soluble salts with calcium and iron, and has a pH range of 1.5-3.5. It also serves as an immune system by destroying microbes.The following substances are found in gastric acid:WaterAcid hydrochloridePepsinogenmucous Intrinsic factorThe parietal cells in the proximal 2/3 (body) of the stomach release gastric acid. The concentration of hydrogen ions in parietal cell secretions is 1-2 million times that of blood. Chloride is released against both a concentration and an electric gradient, and active transport is required for the parietal cell to produce acid.The following is how stomach acid is secreted:1. Gastric acid secretion is dependent on the H+/K+ ATPase (proton pump) situated in the canalicular membrane. The breakdown of water produces hydrogen ions within the parietal cell. The hydroxyl ions produced in this reaction mix quickly with carbon dioxide to generate bicarbonate ions. Carbonic anhydrase is the enzyme that catalyses this process.2. In return for chloride, bicarbonate is carried out of the basolateral membrane. The ‘alkaline tide’ occurs when bicarbonate is released into the bloodstream, resulting in a modest rise in blood pH. The parietal cell’s intracellular pH is maintained by this procedure. Conductance channels carry chloride and potassium ions into the lumen of canaliculi.3. Through the action of the proton pump, hydrogen ions are pushed out of the cell and into the lumen in exchange for potassium; potassium is thus efficiently recycled.4. The canaliculi accumulate osmotically active hydrogen ions, which creates an osmotic gradient across the membrane, allowing water to diffuse outward.
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This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 40
Incorrect
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A 66-year-old female presents to the Emergency Department with a nose bleed. She says that she has been having frequent episodes of nose bleeds over the past four months, along with increasing fatigue and some weight loss. On examination, she has a diffuse petechial rash and hypertrophy of the gingiva. Which one of the following conditions is this patient most likely to have?
Your Answer: Chronic myeloid leukaemia (CML)
Correct Answer: Acute myeloid leukaemia (AML)
Explanation:The history of nosebleeds and fatigue, and gingival hyperplasia presents a typical picture of acute myeloid leukaemia. Leukemic infiltrates within the gingiva cause hypertrophy and distinguish this condition from other types of leukaemia. The fatigue is secondary to anaemia, while the nosebleeds are caused by thrombocytopenia secondary to leukemic infiltration of bone marrow. Patients may also report frequent infections secondary to neutropenia and hepatosplenomegaly.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 41
Correct
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When calculating the ventilation over perfusion ratio of a male patient, you should remember the ideal V/Q ratio for this patient to compare with his results. What is the approximate ventilation value for a healthy male patient?
Your Answer: 5 L/min
Explanation:The ventilation/perfusion ratio (V/Q ratio) is a ratio used to assess the efficiency and adequacy of the matching ventilation and perfusion. The ideal V/Q ratio is 1. In an average healthy male, the ventilation value is approximately 5 L/min and the perfusion value is approximately 5 L/min. Any mismatch between ventilation and perfusion will be evident in the V/Q ratio. If perfusion is normal but ventilation is reduced, the V/Q ratio will be less than 1, whereas if ventilation is normal but perfusion is reduced, the V/Q ratio will be greater than 1. If the alveoli were ventilated but not perfused at all, then the V/Q ratio would be infinity.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 42
Incorrect
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You evaluate a 80-year-old man who has a history of persistent heart failure and discover that he has generalised oedema.Which of the following claims regarding capillary hydrostatic pressure (P c) is false?
Your Answer: P c is the main driver for pushing fluid out of the capillary bed
Correct Answer: P c increases along the length of the capillary, from arteriole to venule
Explanation:The capillary hydrostatic pressure (Pc) is normally between 15 and 30 millimetres of mercury. Pc Decreases along the capillary’s length, mirroring the arteriolar and venule pressures proximally and distally.Pc is determined by the ratio of arteriolar resistance (RA) to venular resistance (RV).When the RA/RV ratio is high, the pressure drop across the capillary is modest, and Pcis is close to venule pressure.When the ratio of RA/RV is low, the pressure drop across the capillary is considerable, and Pcis is close to arteriolar pressure.Pcis closer to the venule pressure and thus more responsive to changes in venous pressure than arteriolar pressure when RA/RV is high.Pcis the major force behind fluid pushing out of the capillary bed and into the interstitium.It is also the most variable of the forces affecting fluid transport at the capillary, partly because sympathetic-mediated arteriolar vasoconstriction varies.
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This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
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Question 43
Correct
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Fenestrated capillaries are typically found where in the body:
Your Answer: Renal glomeruli
Explanation:Fenestrated capillaries, found in renal glomeruli, endocrine glands and intestinal villi, are more permeable than continuous capillaries with less tight junctions, and the endothelial cells are also punctured by pores which allow large amounts of fluids or metabolites to pass.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 44
Correct
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A 45-year-old man had a painless superficial inguinal lymphadenopathy. It was later found to be malignant. Which of the following parts of the body is most likely the origin of this cancerous lymph node?
Your Answer: Anal canal
Explanation:A cancer of the anal canal below the pectinate line would spread to the superficial inguinal lymph nodes. Anal cancer often spreads through lymphatic drainage to the internal iliac lymph nodes in lesions above the pectinate line and to the superficial inguinal lymph nodes in lesions below the pectinate line.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 45
Correct
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A 26 year old male presents to emergency room with a 2 day history of burning pain when passing urine, accompanied by a green urethral discharge. Gonorrhoea is suspected. The first line antibiotic for this condition is which of the following?
Your Answer: Ceftriaxone
Explanation:When there is a high suspicion of gonorrhoea from clinical features, empiric treatment should be commenced whilst waiting for laboratory confirmation. The first line treatment for uncomplicated anogenital and pharyngeal disease includes ceftriaxone 500 mg IM (single dose) + azithromycin 1 g orally as a single dose. This covers concomitant chlamydia infection. For all people who have been treated for gonorrhoea, a test of cure is recommended
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 46
Incorrect
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Regarding nitrous oxide, which of the following statements is CORRECT:
Your Answer: Prolonged or repeated exposure may result in a microcytic anaemia.
Correct Answer: Nitrous oxide may be used for maintenance of anaesthesia where its use allows reduced dosage of other agents.
Explanation:For anaesthesia, nitrous oxide is commonly used in a concentration of around 50 – 66% in oxygen in association with other inhalation or intravenous agents. Nitrous oxide cannot be used as the sole anaesthetic agent due to lack of potency, but is useful as part of a combination of drugs since it allows reduction in dosage of other agents. Exposure to nitrous oxide for prolonged periods, either by continuous or by intermittent administration, may result in megaloblastic anaemia as a result of interference with the action of vitamin B12. Nitrous oxide increases cerebral blood flow and should be avoided in patients with, or at risk of, raised intracranial pressure. Nitrous oxide may be administered by any trained personnel experienced in its use.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 47
Correct
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Which of the following vitamins is not paired correctly with its deficiency syndrome:
Your Answer: Vitamin B12 - Wernicke-Korsakoff syndrome
Explanation:Clinical Effects of vitamin deficiency include:Vitamin C – ScurvyThiamine (Vitamin B1) – Beriberi/Wernicke-Korsakoff syndromeVitamin B12 – Megaloblastic anaemia/Subacute combined degeneration of spinal cordFolate – Megaloblastic anaemiaVitamin D – Osteomalacia/RicketsVitamin K – Defective clottingVitamin A – Blindness
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 48
Incorrect
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A 71-year-old woman is treated with co-amoxiclav for a chest infection but she returns 1 week later. Her chest infection has resolved but she developed a profuse, offensive smelling diarrhoea and abdominal cramps. You suspect Clostridium difficile associated diarrhoea (CDAD).ONE of these statements is true concerning this diagnosis.
Your Answer: Clostridium difficile is a Gram-negative bacteria
Correct Answer: The gold standard for the diagnosis of Clostridium difficile colitis is cytotoxin assay
Explanation:Clostridium difficile, a Gram-positive, anaerobic, spore forming bacteria is present in the gut of approximately 3% of healthy adults (2012 UK HPA estimates). Following use of broad spectrum antibiotics, which alter normal gut flora, Clostridium difficile associated diarrhoea (CDAD) occurs.Alcohol hand gel is not effective against Clostridium Difficile spores. Hand washing with soap and water is very essential for healthcare workers who come in contact with it.Currently, the gold standard for the diagnosis of Clostridium difficile colitis is cytotoxin assay. Stool culture to detect Clostridium difficile is not specific for pathogenic strains, is expensive and therefore not specific for a diagnosis of CDAD
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 49
Incorrect
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Which of the following is NOT an adverse effect associated with statin therapy:
Your Answer: Interstitial lung disease
Correct Answer: Aplastic anaemia
Explanation:Adverse effects of statins include:, Headache, Epistaxis, Gastrointestinal disorders (such as constipation, flatulence, dyspepsia, nausea, and diarrhoea), Musculoskeletal and connective tissue disorders (such as myalgia, arthralgia, pain in the extremity, muscle spasms, joint swelling, and back pain), Hyperglycaemia and diabetes, Myopathy and rhabdomyolysis, Interstitial lung disease and Hepatotoxicity
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 50
Incorrect
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Which patients are particularly susceptible to infection with herpes simplex, those with:
Your Answer: Asplenia
Correct Answer: T-cell deficiency
Explanation:Cell-mediated immunity, especially the action of cytotoxic T-cells, is essential in the control of herpesvirus infections and patients with T-cell deficiency are at particular risk of reactivation and severe infection. T-cell deficiency may follow HIV infection, chemotherapy, corticosteroid therapy or organ transplantation.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 51
Correct
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Hepatitis A is transmitted by which of the following routes:
Your Answer: Faecal-oral route
Explanation:Hepatitis A transmission is by the faecal-oral route; the virus is excreted in bile and shed in the faeces of infected people.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 52
Incorrect
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A 40-year-old man with episodes of blood in urine and flank pain that are recurrent presents for management. He has a history of hypertension that is difficult to control and recurrent urinary tract infections. Other findings are: bilateral masses in his flanks and haematuria (3+ on dipstick).What is the most likely diagnosis?
Your Answer: Renal artery stenosis
Correct Answer: Polycystic kidney disease
Explanation:Autosomal dominant polycystic kidney disease (ADPKD) presents with abdominal or loin discomfort due to the increasing size of the kidneys, acute loin pain with or without haematuria, hypertension, and male infertility. It is the most common cause of serious renal disease and the most common inherited cause of renal failure in adults. Alport syndrome has hearing loss and eye abnormalities in addition to symptoms of kidney disease.Renal cell carcinoma presents with additional features of unexplained weight loss, loss of appetite, fever of unknown origin and anaemia.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 53
Incorrect
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Which of the following is NOT mainly characterised by intravascular haemolysis:
Your Answer: Thrombotic thrombocytopenic purpura
Correct Answer: Beta-Thalassaemia
Explanation:Causes of intravascular haemolysis:Haemolytic transfusion reactionsG6PD deficiencyRed cell fragmentation syndromesSome severe autoimmune haemolytic anaemiasSome drug-and infection-induced haemolytic anaemiasParoxysmal nocturnal haemoglobinuria
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This question is part of the following fields:
- Haematology
- Pathology
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Question 54
Incorrect
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Which of the following nerves supplies the abductor pollicis brevis?
Your Answer: The radial nerve
Correct Answer: The recurrent branch of the median nerve
Explanation:Abductor pollicis brevis is innervated by the recurrent (thenar) branch of median nerve (root value C8 and T1).
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 55
Correct
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Fusidic acid is primarily indicated for infections caused by which of the following microorganisms:
Your Answer: Staphylococcal infections
Explanation:Fusidic acid is a narrow spectrum antibiotic used for staphylococcal infections, primarily topically for minor staphylococcal skin (impetigo) or eye infection. It is sometimes used orally for penicillin-resistant staphylococcal infection, including osteomyelitis or endocarditis, in combination with other antibacterials.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 56
Correct
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A patient has suffered a nerve injury that has caused weakness of the pectoralis minor muscle.Pectoralis minor receives its innervation from which of the following nerves? Select ONE answer only.
Your Answer: Medial pectoral nerve
Explanation:Pectoralis minor is a thin, triangular muscle that is situated in the upper chest. It is thinner and smaller than pectoralis major. It is innervated by the medial pectoral nerve.The origin of pectoralis minor is the 3rdto the 5thribs, near the costal cartilages. It inserts into the medial border and superior surface of the coracoid process of the scapula.The main action of pectoralis minor is to draw the scapula inferiorly and anteriorly against the thoracic wall. This serves to stabilise the scapula.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 57
Incorrect
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In which of the following would you NOT typically see a neutropaenia:
Your Answer: Chloramphenicol therapy
Correct Answer: Asplenism
Explanation:Causes of neutropaenia:Drug-induced (e.g. chemotherapy, chloramphenicol, co-trimoxazole, phenytoin, carbamazepine, carbimazole, furosemide, chloroquine, clozapine, some DMARDs)Benign (racial or familial)CyclicalImmune (e.g. SLE, Felty’s syndrome, hypersensitivity and anaphylaxis)LeukaemiaInfections (e.g. HIV, hepatitis, fulminant bacterial infection)General PancytopaeniaHypersplenism, aplastic anaemia, malignant infiltration of bone marrow, megaloblastic anaemia, chemotherapy, myelodysplasia
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 58
Incorrect
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The QRS duration of a broad-complex tachyarrhythmia is:
Your Answer: Greater than 0.12 s
Correct Answer: Greater than or equal to 0.12 s
Explanation:It’s a broad-complex tachycardia if the QRS duration is 0.12 seconds or more. It’s a narrow-complex tachycardia if the QRS complex is shorter than 0.12 seconds. The QRS duration should be examined if the patient with tachyarrhythmia is stable. Â
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 59
Correct
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You examine a resuscitated patient who has been diagnosed with ventricular tachycardia. The patient's hemodynamics are normal. You intended to prescribe amiodarone to him, but you can't because he has a contraindication.In these circumstances, which of the following is a contraindication to using amiodarone?
Your Answer: Sinus node disease
Explanation:Amiodarone is an anti-arrhythmic medication that can be used to treat both ventricular and atrial arrhythmias.The use of amiodarone is contraindicated in the following situations:Conduction disturbances that are severe (unless pacemaker fitted)Sinus node disease is a condition that affects the lymph nodes in (unless pacemaker fitted)Sensitivity to iodineBlockage of the Sino-atrial heart valve (except in cardiac arrest)Bradycardia in the sinuses (except in cardiac arrest)Thyroid disorders
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 60
Incorrect
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A 40-year-old man with reduced urine output, nausea, and confusion also has a 150% rise of creatinine from baseline over the past 7 days. A diagnosis of acute kidney injury (AKI) is made after more tests are done.His AKI stage is?
Your Answer: Stage 3
Correct Answer: Stage 2
Explanation:This patient with a 150% rise of creatinine above baseline within 7 days has stage 2 Acute kidney injury (AKI).AKI stages are as follows:Stage 1Creatinine rise of 26 micromole/L or more within 48 hours, orCreatinine rise of 50-99% from baseline within 7 days (1.5-1.99 x baseline),orUrine output <0.5 mL/kg/hour for more than 6 hoursStage 2Creatinine rise of 100-199% from baseline within 7 days (2.0-2.99 x baseline),orUrine output <0.5 mL/kg/hour for more than 12 hoursStage 3Creatinine rise of 200% or more from baseline within 7 days (3.0 or more x baseline), orCreatinine rise to 354 micromole/L or more with acute rise of 26 micromole/L or more within 48 hours or 50% or more rise within 7 days, orUrine output <0.3 mL/kg/hour for 24 hours or anuria for 12 hours
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 61
Correct
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Which of the following is characterised by passive carrier-mediated transport down a chemical concentration gradient:
Your Answer: Facilitated diffusion
Explanation:Facilitated diffusion is the process of spontaneous passive transport of molecules or ions down their concentration gradient across a cell membrane via specific transmembrane transporter (carrier) proteins. The energy required for conformational changes in the transporter protein is provided by the concentration gradient rather than by metabolic activity.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 62
Correct
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A young male has presented to you with respiratory depression and small pupils on examination. You diagnose opioid overdose and immediately start therapy with Naloxone.Which of the following statements is TRUE regarding naloxone?
Your Answer: It can be given by a continuous infusion if repeated doses are required
Explanation:Naloxone is a short-acting, specific antagonist of mu(μ)-opioid receptors. It is used to reverse the effects of opioid toxicity. It can be given by a continuous infusion if repeated doses are required and the infusion rate is adjusted according to the vital signs. Initially, the infusion rate can be set at 60% of the initial resuscitative IV dose per hour.Naloxone has a shorter duration of action (6-24 hours) than most opioids and so close monitoring according to the respiratory rate and depth of coma and repeated injections are necessary. When repeated doses are needed in opioid addicts, naloxone administration may precipitate a withdrawal syndrome with abdominal cramps, nausea and diarrhoea, but these usually settle within 2 hours.An initial dose of 0.4 to 2 mg can be given intravenously and can be repeated at 2 to 3-minute intervals to a maximum of 10mg. If the intravenous route is inaccessible, naloxone can be administered via an IO line, subcutaneously (SQ), IM, or via the intranasal (IN) route.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 63
Incorrect
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Regarding cross-sectional studies, which of the following statements is CORRECT:
Your Answer: They are particularly suitable for estimating incidence of a disease.
Correct Answer: They are particularly suitable for estimating point prevalence.
Explanation:Cross-sectional studies aim to provide data about population health, normal ranges of biological parameters, and disease prevalence or severity by observing the entire population, or a representative subset, at a single point in time. Cross-sectional studies are relatively simple and quick to perform and can be used to study multiple outcomes, but are subject to confounding and recall bias and are not suitable for studying rare diseases. Cross-sectional studies cannot be used to assess causation or to consider trends over time.
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This question is part of the following fields:
- Evidence Based Medicine
- Study Methodology
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Question 64
Correct
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A patient complains of stomach ache. You see a midline scar in the epigastric area when you examine the abdomen. Upon further interrogation, the patient reveals that she had a subtotal gastrectomy for recurring stomach ulcers several years ago. The stomach mucosa secretes a variety of vital compounds, and her ability to secrete some of these molecules has been harmed as a result of his surgery.The stomach mucous neck cells secrete which of the following substances?
Your Answer: Bicarbonate
Explanation:Foveolar cells, also known as gastric mucous-neck cells, are cells that line the stomach mucosa and are found in the necks of the gastric pits. Mucus and bicarbonate are produced by these cells, which prevent the stomach from digesting itself. At pH 4, the mucous allows the acid to penetrate the lining, while below pH 4, the acid is unable to do so. Viscous fingering is the term for this procedure.The table below summarizes the many cell types found in the stomach, as well as the substances secreted by each cell type and the function of the secretion:Cell type/ Substance secreted/ Function of secretionParietal cells/ Hydrochloric acid/ Kills microbes and activates pepsinogenParietal cells/ Intrinsic factor/Binds to vitamin B12 and facilitates its absorptionChief cells/ Pepsinogen/ Protein digestionChief cells/ Gastric lipase/ Fat digestionG-cells/ Gastrin/ Stimulates gastric acid secretionEnterochromaffin-like cells (ECL cells) /Histamine/ Stimulates gastric acid secretionMucous-neck cells/ Mucous and bicarbonate/ Protects stomach epithelium from acidD-cells/ Somatostatin/ Inhibits gastric acid secretion
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This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 65
Correct
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An elderly female with a diagnosed psychiatric illness was prescribed prochlorperazine for her complaints of dizziness and nausea. Two days later, she returned to the clinic with no improvement in the symptoms. Which one of the following is the mechanism of action of prochlorperazine?
Your Answer: Dopamine receptor antagonism
Explanation:Prochlorperazine is a phenothiazine drug as it is categorized as a first-generation antipsychotic. It mainly blocks the D2 (dopamine 2) receptors in the brain. Along with dopamine, it also blocks histaminergic, cholinergic, and noradrenergic receptors.It exerts its antiemetic effect via dopamine (D2) receptor antagonist. It is used to treat nausea and vomiting of various causes, including labyrinthine disorders.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 66
Incorrect
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Which of the following is NOT a typical electrolyte disturbance caused by furosemide:
Your Answer: Hypochloraemia
Correct Answer: Hypercalcaemia
Explanation:Adverse effects of loop diuretics include:Mild gastrointestinal disturbances, pancreatitis and hepatic encephalopathyHyperglycaemiaAcute urinary retentionWater and electrolyte imbalanceHyponatraemia, hypocalcaemia, hypokalaemia, hypomagnesaemia, hypochloraemiaHypotension, hypovolaemia, dehydration, and venous thromboembolismMetabolic alkalosisHyperuricaemiaBlood disorders (bone marrow suppression, thrombocytopenia, and leucopenia)Visual disturbance, tinnitus and deafnessHypersensitivity reactions
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 67
Correct
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A 10-year-old girl that appears systemically well presents with a honey-crusted scab close to the corner of her mouth and states that the area is slightly itchy but not painful. The diagnosis given was impetigo.What is most likely the mode of transmission of the causative agent of the said diagnosis?
Your Answer: Direct contact
Explanation:Impetigo is a common pyoderma that is most often seen in children. Historically, most cases were caused by group A streptococci (GAS; Streptococcus pyogenes), although S. aureus has become the predominant pathogen over the last 15 years.A bullous form of impetigo accounts for approximately 10% of cases. It is caused by strains of S. aureus that produce exfoliative toxins leading to the formation of bullae, which quickly rupture and form a transparent, light brown crust.Impetigo is spread mainly by person-to-person contact; it is rapidly spread through direct transmission. The diagnosis of impetigo can be made from a Gram stain and culture of the vesicular contents.
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 68
Correct
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Which of the following intravenous induction drugs results in the highest drop in blood pressure:
Your Answer: Propofol
Explanation:Propofol’s most frequent side effect is hypotension, which affects 17% of paediatric patients and 26% of adults. This is attributable to systemic vasodilation as well as a decrease in preload and afterload. Propofol has a little negative inotropic impact as well. The drop in blood pressure is dosage-dependent and is more noticeable in the elderly, thus this should be expected.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 69
Correct
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The patient is a 66-year-old woman who has troublesome bilateral ankle swelling. This has been happening since she began taking a new antihypertensive medication a few weeks ago.Which of the following medications is most likely to be the cause of this adverse reaction?
Your Answer: Amlodipine
Explanation:Amlodipine is a calcium-channel blocker that is frequently used to treat hypertension. Ankle swelling is a very common side effect of calcium-channel blockers, and it occurs quite frequently.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 70
Correct
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A patient complains of stomach ache. You see a midline scar in the epigastric area when you examine the abdomen. Upon further interrogation, the patient reveals that she had a subtotal gastrectomy for recurring stomach ulcers several years ago. The stomach mucosa secretes a variety of vital compounds, and her ability to secrete some of these molecules has been harmed as a result of his surgery.The gastric ECL cells secrete which of the following substances?
Your Answer: Histamine
Explanation:Enterochromaffin-like cells (ECL cells) are a type of neuroendocrine cell located beneath the epithelium in the stomach glands. They’re most typically located near the parietal cells of the stomach. The ECL cells’ primary role is to produce histamine, which stimulates the formation of stomach acid by the parietal cells.The table below summarizes the many cell types found in the stomach, as well as the substances secreted by each cell type and the function of the secretion:Cell type/ Substance secreted/ Function of secretionParietal cells/ Hydrochloric acid/ Kills microbes and activates pepsinogenParietal cells/ Intrinsic factor/Binds to vitamin B12 and facilitates its absorptionChief cells/ Pepsinogen/ Protein digestionChief cells/ Gastric lipase/ Fat digestionG-cells/ Gastrin/ Stimulates gastric acid secretionEnterochromaffin-like cells (ECL cells) /Histamine/ Stimulates gastric acid secretionMucous-neck cells/ Mucous and bicarbonate/ Protects stomach epithelium from acidD-cells/ Somatostatin/ Inhibits gastric acid secretion
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This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 71
Correct
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A 39-year-old guy comes to the emergency room with a persistent nasal bleed. You suspect the bleeding is coming from Little's area based on your examination. Which of the blood vessels listed below is most likely to be involved:
Your Answer: Sphenopalatine and superior labial arteries
Explanation:The Kiesselbach plexus is a vascular network formed by five arteries that supply oxygenated blood to the nasal septum, which refers to the wall separating the right and left sides of the nose. The five arteries that form the Kiesselbach plexus: the sphenopalatine artery, which branches from the maxillary artery originating behind the jawbone; the anterior ethmoidal artery, which branches from the ophthalmic artery behind the eye; the posterior ethmoidal artery, which also branches from the ophthalmic artery; the septal branch of the superior labial artery, which is a branch of the facial artery supplying blood to all of the superficial features of the face; and finally, the greater palatine artery, which is a terminal branch of the maxillary artery.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 72
Correct
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Caseous necrosis is typically seen in which of the following:
Your Answer: Tuberculosis
Explanation:Caseous necrosis is most commonly seen in tuberculosis. Histologically, the complete loss of normal tissue architecture is replaced by amorphous, granular and eosinophilic tissue with a variable amount of fat and an appearance reminiscent of cottage cheese.
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This question is part of the following fields:
- Inflammatory Responses
- Pathology
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Question 73
Correct
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All of the following cause bronchoconstriction, EXCEPT for:
Your Answer: Adrenaline
Explanation:Factors causing bronchoconstriction:Via muscarinic receptorsParasympathetic stimulationStimulation of irritant receptorsInflammatory mediators e.g. histamine, prostaglandins, leukotrienesBeta-blockers
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 74
Correct
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Which of the following statements concerning the facial nerve is INCORRECT?
Your Answer: Forehead sparing in facial nerve palsy is indicative of a lower motor neuron lesion.
Explanation:In facial nerve palsy, LMN damage will involve the forehead and there will be an inability to close the eyes due to paralysis of the orbicularis oculi or raise the eyebrows due to paralysis of the occipitofrontalis muscle.UMN damage causes sparing of the forehead as the occipitofrontalis and orbicularis oculi muscles have bilateral cortical representation.
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This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
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Question 75
Correct
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A 54-year-old man returns from a recently holiday on a cruise ship with a dry cough and a fever. Today he has also had several episodes of diarrhoea and has developed bilateral pleuritic chest pain. He states that he is short of breath, most notably on exertion. He had been prescribed amoxicillin by the cruise ship doctor a few days earlier but has not seen any improvement.Which of the following is the most likely causative organism? Select ONE answer only.
Your Answer: Legionella pneumophila
Explanation:Legionella pneumophilais a Gram negative bacterium that is found in natural water supplies and in the soil, transmitted predominantly via inhalation of aerosols generated from contaminated water (direct person-to-person spread of infected patients does not occur). It is the cause of Legionnaires’ disease. Outbreaks of Legionnaires’ disease have been linked to poorly maintained air conditioning systems, whirlpool spas and hot tubs.The clinical features of the pneumonic form of Legionnaires’ disease include:Mild flu-like prodrome for 1-3 daysCough (usually non-productive and occurs in approximately 90%)Pleuritic chest painHaemoptysisHeadacheNausea, vomiting and diarrhoeaAnorexiaLegionella pneumophilainfections can be successfully treated with macrolide antibiotics, such as erythromycin, or quinolones, such as ciprofloxacin. Tetracyclines, such as doxycycline, can also be used.The syndrome of inappropriate antidiuretic hormone secretion (SIADH) can occur with Legionnaires’ disease and will result in hyponatraemia as is seen in this case.Legionella pneumophilainfections are resistant to amoxicillin but can be successfully treated with macrolide antibiotics, such as erythromycin, or quinolones, such as ciprofloxacin. Tetracyclines, such as doxycycline, can also be used. The majority of cases of Legionnaires’ disease are caused by Legionella pneumophila, however many other species of Legionella have been identified.Legionella longbeachae is another less commonly encountered species that has also been implicated in outbreaks. It is predominantly found in soil and potting compost, and has caused outbreaks of Pontiac fever, the non-respiratory and less severe variant of Legionnaires’ disease.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 76
Correct
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Which one these is an example of a cause of an exudate?
Your Answer: Subphrenic abscess
Explanation:An exudate is an inflammatory fluid emanating from the intravascular space due to changes in the permeability of the surrounding microcirculation.Some common causes of exudates are: pneumonia, empyema, lung cancer, breast cancer, cancer of the pleura, SLE, rheumatoid arthritis, pericarditis, subphrenic abscess, chylothorax.Myxoedema, nephrotic syndrome, congestive cardiac failure, and liver cirrhosis all cause TRANSUDATE.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 77
Incorrect
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In a ward round, you come across a patient's treatment chart prescribed an antibiotic to fight his infection. This antibiotic is an inhibitor of cell wall synthesis. Which of the following antimicrobial drugs is prescribed to this patient?
Your Answer: Tetracycline
Correct Answer: Benzylpenicillin
Explanation:Penicillins and cephalosporins are the major antibiotics that inhibit bacterial cell wall synthesis. They inactivate transpeptidases that help cross-link peptidoglycans in cell walls. Isoniazid decreases the synthesis of mycolic acids in mycobacterium.Clarithromycin binds to the 50S subunit of ribosomes and inhibits protein synthesis. Metronidazole and the other 5-nitroimidazole agents inhibit nucleic acid synthesis by forming toxic free radical metabolites in the bacterial cell that damage DNA. Tetracycline bind to 30S and prevent attachment of aminoacyl-tRNA.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 78
Correct
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Regarding gas exchange at the alveolar-capillary membrane, which of the following statements is CORRECT:
Your Answer: Transfer of oxygen is usually perfusion-limited.
Explanation:Gas exchange between alveolar air and blood in the pulmonary capillaries takes place by diffusion across the alveolar-capillary membrane. Diffusion occurs from an area of high partial pressure to an area of low partial pressure, thus the driving force for diffusion is the alveolar-capillary partial pressure gradient. Diffusion occurs until equilibrium is reached, but random movement of particles continues to occur and this is known as dynamic equilibrium. The diffusing capacity for oxygen (DLO2) cannot be measured directly but the rate of diffusion in the lungs can be estimated by measuring the diffusing capacity of the lungs for carbon monoxide (DLCO), not by measuring total lung capacity. The rate of transfer of a gas may be diffusion or perfusion limited; carbon monoxide transfer is diffusion-limited, oxygen transfer is usually perfusion-limited.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 79
Correct
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1-alpha-hydroxylase is a cytochrome p450 enzyme that is involved in the production of vitamin D's hormonally active metabolite.Which of the following promotes the activity of 1-alpha-hydroxylase?
Your Answer: Parathyroid hormone
Explanation:1-alpha-hydroxylase converts 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol in the kidney.The key regulatory point in the formation of 1,25-dihydroxycholecalciferol is 1-alpha-hydroxylase, which is promoted by parathyroid hormone or hypophosphatemia.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 80
Incorrect
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Lidocaine's antiarrhythmic mode of action is as follows:
Your Answer: Blocks open Na+ channels
Correct Answer: Blocks inactivated Na+ channels
Explanation:Lidocaine is a class 1B antidysrhythmic; combines with fast Na channels and thereby inhibits recovery after repolarization, resulting in decreasing myocardial excitability and conduction velocity. However, in ischaemic areas, where anoxia causes depolarisation and arrhythmogenic activity, many Na+ channels are inactivated and therefore susceptible to lidocaine.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 81
Incorrect
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All of the following statements are considered true regarding randomized control trials, except:
Your Answer: They can help to overcome ‘publication bias’
Correct Answer: They can eliminate the need for further studies
Explanation:Meta-analysis is a quantitative, formal, epidemiological study design used to systematically assess previous research studies to derive conclusions about that body of research. Outcomes from a meta-analysis may include a more precise estimate of the effect of treatment or risk factor for disease, or other outcomes, than any individual study contributing to the pooled analysis. The examination of variability or heterogeneity in study results is also a critical outcome.The benefits of meta-analysis include a consolidated and quantitative review of a large, and often complex, sometimes apparently conflicting, body of literature. The specification of the outcome and hypotheses that are tested is critical to the conduct of meta-analyses, as is a sensitive literature search.Important medical questions are typically studied more than once, often by different research teams in different locations. In many instances, the results of these multiple small studies of an issue are diverse and conflicting, which makes the clinical decision-making difficult. The need to arrive at decisions affecting clinical practise fostered the momentum toward evidence-based medicine. Evidence-based medicine may be defined as the systematic, quantitative, preferentially experimental approach to obtaining and using medical information. Therefore, meta-analysis, a statistical procedure that integrates the results of several independent studies, plays a central role in evidence-based medicine.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 82
Correct
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A 58-year-old woman presents with symptoms of increase in weight, proximal muscular weakening and withering, easy bruising, and acne. You notice that she has a full, plethoric aspect to her face, as well as significant supraclavicular fat pads, when you examine her. She has previously been diagnosed with Cushing's syndrome.Cushing's syndrome is most commonly caused by which of the following?
Your Answer: Iatrogenic administration of corticosteroids
Explanation:Cushing’s syndrome is a group of symptoms and signs brought on by long-term exposure to high amounts of endogenous or exogenous glucocorticoids. Cushing’s syndrome affects about 10-15 persons per million, and it is more common in those who have had a history of obesity, hypertension, or diabetes.Iatrogenic corticosteroid injection is the most prevalent cause of Cushing’s syndrome. Cushing’s illness is the second most prevalent cause of Cushing’s syndrome. Cushing’s disease is distinct from Cushing’s syndrome in that it refers to a single cause of the illness, a pituitary adenoma that secretes high quantities of ACTH, which raises cortisol levels.Cushing’s syndrome has several endogenous sources, including:Cushing’s disease is caused by a pituitary adenoma.Adrenal adenoma Ectopic corticotropin syndrome, e.g. small cell cancer of the lungAdrenal carcinoma is a cancer of the adrenal gland.Hyperplasia of the adrenal glands
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 83
Correct
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While studying fluid homeostasis in the body, you encounter the term exudate. Exudate is a fluid that leaks out of the intravascular space due to changes in the permeability of the microcirculation secondary to inflammation. Which ONE of the following conditions would not be listed among the causes of an exudate?
Your Answer: Myxoedema
Explanation:An exudate is an inflammatory fluid that leaks out of the intravascular space due to increased vascular permeability and intravascular pressure. It is mostly caused by local processes and can occur in the following conditions:1) Infection (e.g. pneumonia)2) Malignancy3) Pericarditis4) Collagen vascular diseases, e.g., Rheumatoid ArthritisMyxoedema is a state of severe hypothyroidism in which deposition of mucopolysaccharides occurs in the dermis. This causes a transudative effusion, typically in the pretibial region.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 84
Correct
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Which of the following statements is correct regarding the lymphatic system?
Your Answer: Lymphatic vessels contain both smooth muscle and unidirectional valves.
Explanation:Fluid filtration out of the capillaries is usually slightly greater than fluid absorption into the capillaries. About 8 L of fluid per day is filtered by the microcirculation and returns to the circulation by the lymphatic system. Lymphatic capillaries drain into collecting lymphatics, then into larger lymphatic vessels. Both of these containing smooth muscle and unidirectional valves. From this point, lymph is propelled by smooth muscle constriction and vessel compression by body movements into afferent lymphatics. It then goes to the lymph nodes where phagocytes remove bacteria and foreign materials. It is here that most fluid is reabsorbed by capillaries, and the remainder returns to the subclavian veins via efferent lymphatics and the thoracic duct. The lymphatic system has a major role to play in the body’s immune defence and also has a very important role in the absorption and transportation of fats.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 85
Correct
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Which of the following laboratory findings are suggestive of functional hyposplenism:
Your Answer: Howell-Jolly bodies
Explanation:Functional hyposplenism is characterised by the blood film findings of Howell-Jolly bodies or siderotic granules on iron staining. The most frequent cause is surgical removal of the spleen e.g. after traumatic rupture, but hyposplenism can also occur in sickle cell anaemia, gluten-induced enteropathy, amyloidosis and other conditions.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 86
Incorrect
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A patient is diagnosed as having a glucagonoma. Her blood serum glucagon concentration is 1246 pg/mL.Glucagon INHIBITS which of the following processes? Select ONE answer only.
Your Answer: Gluconeogenesis
Correct Answer: Glycolysis
Explanation:Glucagon is a peptide hormone that is produced and secreted by alpha cells of the islets of Langerhans, which are located in the endocrine portion of the pancreas. The main physiological role of glucagon is to stimulate hepatic glucose output, thereby leading to increases in glycaemia. It provides the major counter-regulatory mechanism to insulin in maintaining glucose homeostasis.Hypoglycaemia is the principal stimulus for the secretion of glucagon but may also be used as an antidote in beta-blocker overdose and in anaphylaxis in patients on beta-blockers that fail to respond to adrenaline. Glucagon then causes:GlycogenolysisGluconeogenesisLipolysis in adipose tissueThe secretion of glucagon is also stimulated by:AdrenalineCholecystokininArginineAlanineAcetylcholineThe secretion of glucagon is inhibited by:InsulinSomatostatinIncreased free fatty acidsIncreased urea productionGlycolysis is the metabolic pathway that converts glucose into pyruvate. The free energy released by this process is used to form ATP and NADH. Glycolysis is inhibited by glucagon, and glycolysis and gluconeogenesis are reciprocally regulated so that when one cell pathway is activated, the other is inactive and vice versa.Glucagon has a minor effect of enhancing lipolysis in adipose tissue. Lipolysis is the breakdown of lipids and involves the hydrolysis of triglycerides into glycerol and free fatty acids. It makes fatty acids available for oxidation.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 87
Correct
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Polyuria and polydipsia develop in a patient with a history of affective disorders illness who has been on long-term lithium. She has a fluid deprivation test because she is suspected of having nephrogenic diabetic insipidus.Which of the following urine osmolality findings would be the most reliable in confirming the diagnosis?Â
Your Answer: After fluid deprivation <300 mosmol/kg, after IM desmopressin <300 mosmol/kg
Explanation:The inability to produce concentrated urine is a symptom of diabetes insipidus. Excessive thirst, polyuria, and polydipsia are all symptoms of this condition. There are two forms of diabetes insipidus: Nephrogenic diabetes insipidus and cranial (central) diabetes insipidus.A lack of ADH causes cranial diabetic insipidus. Patients with cranial diabetes insipidus can have a urine output of up to 10-15 litres per 24 hours, however most patients can maintain normonatraemia with proper fluid consumption. Thirty percent of cases are idiopathic, while another thirty percent are caused by head injuries. Neurosurgery, brain tumours, meningitis, granulomatous disease (e.g. sarcoidosis), and medicines like naloxone and phenytoin are among the other reasons. There is also a very rare hereditary type that is linked to diabetes, optic atrophy, nerve deafness, and bladder atonia.Renal resistance to the action of ADH causes nephrogenic diabetes insipidus. Urine output is significantly increased, as it is in cranial diabetes insipidus. Secondary polydipsia can keep serum sodium levels stable or raise them. Chronic renal dysfunction, metabolic diseases (e.g., hypercalcaemia and hypokalaemia), and medications, such as long-term lithium use and demeclocycline, are all causes of nephrogenic diabetes insipidus.The best test to establish if a patient has diabetes insipidus vs another cause of polydipsia is the water deprivation test, commonly known as the fluid deprivation test. It also aids in the distinction between cranial and nephrogenic diabetes insipidus. Weight, urine volume, urine osmolality, and serum osmolality are all measured after patients are denied water for up to 8 hours. At the end of the 8-hour period, 2 micrograms of IM desmopressin is given, and measures are taken again at 16 hours.The following are the way results are interpreted:Urine osmolality after fluid deprivation : Urine osmolality after IM desmopressinCranial diabetes insipidus800 mosmol/kgNephrogenic diabetes insipidus<300 mosmol/kg : 800 mosmol/kg : >800 mosmol/kg
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 88
Correct
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Which of the following is an example of continuous data:
Your Answer: Height
Explanation:Continuous data is data where there is no limitation on the numerical value that the variable can take e.g. weight, height.
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 89
Incorrect
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Ipratropium bromide should be used with caution in patients with which of the following conditions:
Your Answer: Convulsive disorders
Correct Answer: Prostatic hyperplasia
Explanation:Ipratropium bromide is an antimuscarinic drug used in the management of acute asthma and COPD. It can provide short-term relief in chronic asthma, but short-acting β2agonists act more quickly and are preferred.The BTS guidelines recommend that nebulised ipratropium bromide (0.5 mg 4-6 hourly) can be added to β2agonist treatment for patients with acute severe or life-threatening asthma or those with a poor initial response to β2 agonist therapy.The aerosol inhalation of ipratropium can be used for short-term relief in mild chronic obstructive pulmonary disease in patients who are not already using a long-acting antimuscarinic drug (e.g. tiotropium).Its maximum effect occurs 30-60 minutes after use; its duration of action is 3-6 hours, and bronchodilation can usually be maintained with treatment three times per day.The commonest side effect of ipratropium bromide is dry mouth. It can also trigger acute closed-angle glaucoma in susceptible patients. Tremor is commonly seen with β2agonists but not with antimuscarinics. Ipratropium bromide should be used with caution in: Men with prostatic hyperplasia and bladder-outflow obstruction (worsened urinary retention has been reported in elderly men), People with chronic kidney disease (CKD) stages 3 and above (because of the risk of drug toxicity), People with angle-closure glaucoma (nebulised mist of antimuscarinic drugs can precipitate or worsen acute angle-closure glaucoma)
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 90
Correct
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Which of the following is the site of secretion of intrinsic factor:
Your Answer: Stomach
Explanation:Intrinsic factor is essential for the absorption of the small amounts of vitamin B12 normally present in the diet from the terminal ileum. The parietal cells of the stomach produce intrinsic factor, and following a gastrectomy, the absorption of vitamin B12 will be markedly reduced, and a deficiency state will exist.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 91
Incorrect
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On her most recent blood tests, a 55 year-old female with a history of hypertension was discovered to be hypokalaemic. She  is diagnosed with primary hyperaldosteronism.Which of the following is a direct action of aldosterone?
Your Answer: Reabsorption of Na + into the proximal convoluted tubule
Correct Answer: Secretion of H + into the distal convoluted tubule
Explanation:Aldosterone is a steroid hormone produced in the adrenal cortex’s zona glomerulosa. It is the most important mineralocorticoid hormone in the control of blood pressure. It does so primarily by promoting the synthesis of Na+/K+ATPases and the insertion of more Na+/K+ATPases into the basolateral membrane of the nephron’s distal tubules and collecting ducts, as well as stimulating apical sodium and potassium channel activity, resulting in increased sodium reabsorption and potassium secretion. This results in sodium conservation, potassium secretion, water retention, and a rise in blood volume and blood pressure.Aldosterone is produced in response to the following stimuli:Angiotensin II levels have risen.Potassium levels have increased.ACTH levels have risen.Aldosterone’s principal actions are as follows:Na+ reabsorption from the convoluted tubule’s distal endWater resorption from the distal convoluted tubule (followed by Na+)Cl is reabsorbed from the distal convoluted tubule.K+ secretion into the convoluted distal tubule’s H+ secretion into the convoluted distal tubule’sÂ
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 92
Correct
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A new chemotherapy drug is being tested. The intervention reduces the risk of death from 10 in 1000 to 5 in 1000. What is the number needed to treat to prevent one death:
Your Answer: 200
Explanation:Absolute risk reduction (ARR) of treatment = risk of death in control group – risk of death in treatment groupARR = (10/1000) – (5/1000) = 5/1000 = 0.005Number needed to treat (NNT) = 1/ARR = 1/0.005 = 200Therefore 200 people would need to be treated to prevent one extra death.
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 93
Incorrect
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Calcium-channel blockers can be divided into two categories: dihydropyridines and non-dihydropyridines. The basic chemical structure of these two classes differs, as does their relative selectivity for cardiac versus vascular L-type calcium channels. The phenylalkylamine class and the benzothiazepine class are two subgroups of non-dihydropyridines.A phenylalkylamine calcium-channel blocker is, for example, which of the following?
Your Answer: Diltiazem
Correct Answer: Verapamil
Explanation:Calcium-channel blockers, also known as calcium antagonists, stop calcium from entering cells through the L-type calcium channel. This causes vascular smooth muscle in vessel walls to relax, resulting in a decrease in peripheral vascular resistance. They can be used for a variety of things, including:HypertensionAnginaAtrial fibrillationMigraineCalcium-channel blockers can be divided into two categories: dihydropyridines and non-dihydropyridines. The basic chemical structure of these two classes differs, as does their relative selectivity for cardiac versus vascular L-type calcium channels.Dihydropyridines have a high vascular selectivity and lower systemic vascular resistance and blood pressure. As a result, they’re frequently used to treat hypertension. Modified release formulations are also used to treat angina, but their powerful systemic vasodilator and pressure-lowering effects can cause reflex cardiac stimulation, resulting in increased inotropy and tachycardia, which can counteract the beneficial effects of reduced afterload on myocardial oxygen demand.The suffix -dpine distinguishes dihydropyridines from other pyridines. Examples of dihydropyridines that are commonly prescribed include:AmlodipineFelodipineNifedipineNimodipineThe phenylalkylamine class and the benzothiazepine class are two subgroups of non-dihydropyridines.Phenylalkylamines are less effective as systemic vasodilators because they are relatively selective for the myocardium. This group of drugs lowers myocardial oxygen demand and reverses coronary vasospasm, making them useful in the treatment of angina. They are also occasionally used to treat arrhythmias. A phenylalkylamine calcium-channel blocker like verapamil is an example.In terms of selectivity for vascular calcium channels, benzothiazepines fall somewhere between dihydropyridines and phenylalkylamines. They can lower arterial pressure without producing the same level of reflex cardiac stimulation as dihydropyridines because they have both cardiac depressant and vasodilator effects. Diltiazem is the only benzothiazepine currently in clinical use.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 94
Correct
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A 55-year-old woman with mild dyspepsia seeks advice from her pharmacist on how to deal with her symptoms. In the first instance, the pharmacist advises her to take an over-the-counter antacid. She buys an antacid that contains aluminium hydroxide, which relieves her symptoms but has a negative side effect.She's most likely to have developed which of the following side effects?
Your Answer: Constipation
Explanation:Aluminium hydroxide is a common antacid that is used to treat ulcer dyspepsia and non-erosive gastro-oesophageal reflux disease.When antacids containing aluminium salts are given to patients with renal impairment, there is a risk of accumulation and aluminium toxicity. If renal function is normal, aluminium accumulation does not appear to be a risk.Because it reduces gastrointestinal phosphate absorption, aluminium hydroxide can also be used to treat hyperphosphatemia in patients with renal failure.Magnesium-based antacids are generally laxative, whereas aluminium-based antacids can be constipating. Renal impairment, angioedema, and anaphylaxis are not significantly increased.
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This question is part of the following fields:
- Gastrointestinal Pharmacology
- Pharmacology
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Question 95
Incorrect
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A 30-year old male is taken to the emergency room after suffering a blunt trauma to the abdomen. He is complaining of severe abdominal pain, however all his other vital signs remain stable. A FAST scan is performed to assess for hemoperitoneum.If hemoperitoneum is present, it is most likely to be observed in which of the following areas?
Your Answer: Para-colic
Correct Answer: Liver
Explanation:The Focused Assessment with Sonography in Trauma (FAST) is an ultrasound protocol developed to assess for hemoperitoneum and hemopericardium. Numerous studies have demonstrated sensitivities between 85% to 96% and specificities exceeding 98%.The FAST exam evaluates four regions for pathologic fluid: (1) the right upper quadrant, (2) the subxiphoid (or subcostal) view, (3) the left upper quadrant, and (4) the suprapubic region.The right upper quadrant (RUQ) visualizes the hepatorenal recess, also known as Morrison’s pouch, the right paracolic gutter, the hepato-diaphragmatic area, and the caudal edge of the left liver lobe. The probe is positioned in the sagittal orientation along the patient’s flank at the level of the 8 to 11 rib spaces. The hand is placed against the bed to ensure visualization of the retroperitoneal kidney. The RUQ view is the most likely to detect free fluid with an overall sensitivity of 66%. Recent retrospective evidence suggests the area along the caudal edge of the left lobe of the liver has the highest sensitivity, exceeding 93%.
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This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 96
Correct
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Question 97
Correct
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Which of the following is required for vitamin B12 absorption:
Your Answer: Intrinsic factor
Explanation:Intrinsic factor is essential for the absorption of the small amounts of vitamin B12 normally present in the diet from the terminal ileum. The parietal cells of the stomach produce intrinsic factor, and following a gastrectomy, the absorption of vitamin B12 will be markedly reduced, and a deficiency state will exist.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 98
Correct
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A 58-year-old man with a long history of depression presents with a deliberate overdose of verapamil tablets, which he is prescribed for a heart condition.What is verapamil's mechanism of action?
Your Answer: L-type calcium channel blockade
Explanation:Overdosing on calcium-channel blockers should always be taken seriously and regarded as potentially fatal. Verapamil and diltiazem are the two most lethal calcium channel blockers in overdose. These work by binding the alpha-1 subunit of L-type calcium channels, preventing calcium from entering the cell. In cardiac myocytes, vascular smooth muscle cells, and islet beta-cells, these channels play an important role.The standard ABC approach should be used to resuscitate all patients as needed. If life-threatening toxicity is expected, intubation and ventilation should be considered early on. If hypotension and shock are developing, early invasive blood pressure monitoring is recommended.The primary goal of specific treatments is to support the cardiovascular system. These are some of them:1. Fluid resuscitation: Give up to 20 mL of crystalloid per kilogramme of body weight.2. Calcium supplementationThis can be a good way to raise blood pressure and heart rate temporarily.via central venous access: 10% calcium gluconate 60 mL IV (0.6-1.0 mL/kg in children) or 10% calcium chloride 20 mL IV (0.2 mL/kg in children)Boluses can be given up to three times in a row.To keep serum calcium >2.0 mEq/L, consider a calcium infusion.3. Atropine: 0.6 mg every 2 minutes up to 1.8 mg is an option, but it is often ineffective.4. HIET (high-dose insulin-euglycemic therapy):The role of HIET in the step-by-step management of cardiovascular toxicity has changed.5. Vasoactive infusions:This was once thought to be a last-ditch measure, but it is now widely recommended that it be used sooner rather than later.Insulin with a short half-life 50 mL of 50 percent glucose IV bolus plus 1 U/kg bolus (unless marked hyperglycaemia present)Short-acting insulin/dextrose infusions should be continued.Glucose should be checked every 20 minutes for the first hour, then hourly after that.Regularly check potassium levels and replace if they fall below 2.5 mmol/L.Titrate catecholamines to effect (inotropy and chronotropy); options include dopamine, adrenaline, and/or noradrenaline infusions.6. Sodium bicarbonate: Use 50-100 mEq sodium bicarbonate (0.5-1.0 mEq/kg in children) in cases where a severe metabolic acidosis develops.7. Cardiac pacing: It can be difficult to achieve electrical capture, and it may not improve overall perfusion.Bypass AV blockade with ventricular pacing, which is usually done at a rate of less than 60 beats per minute.8. Intralipid transportCalcium channel blockers are lipid-soluble agents, so they should be used in refractory cases.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 99
Incorrect
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A 52-year-old man presents to the emergency room with chest pain. He was recently released from the hospital after receiving abciximab during coronary angioplasty.Which of the following is NOT a contraindication to abciximab (ReoPro) treatment?
Your Answer: Stroke within the last 2 years
Correct Answer: Major surgery within the last 6 months
Explanation:Abciximab (ReoPro) is a glycoprotein IIb/IIIa receptor antagonist that is a chimeric monoclonal antibody. It is primarily used during and after coronary artery procedures such as angioplasty to inhibit platelet aggregation.The use of abciximab is contraindicated in the following situations:Internal bleeding is present.Within the last two months, you’ve had major surgery, intracranial surgery, or trauma.Stroke in the previous two yearsIntracranial tumourAneurysm or arteriovenous malformationHaemorrhagic diathesis is a type of haemorrhagic diathesis.VasculitisRetinopathy caused by hypertension
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 100
Correct
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A 33-year-old woman who is investigated for recurrent renal stones is discovered to have a markedly elevated parathyroid hormone (PTH) level.Which of the following would stimulate PTH release under normal circumstances? Select ONE answer only.
Your Answer: Decreased plasma calcium concentration
Explanation:Parathyroid hormone (PTH) is a polypeptide containing 84 amino acids. It is the principal controller of free calcium in the body.PTH is synthesised by and released from the chief cells of the four parathyroid glands that are located immediately behind the thyroid gland.PTH is released in response to the following stimuli:Decreased plasma calcium concentrationIncreased plasma phosphate concentration (indirectly by binding to plasma calcium and reducing the calcium concentration)PTH release is inhibited by the following factors:Normal/increased plasma calcium concentrationHypomagnesaemiaThe main actions of PTH are:Increases plasma calcium concentrationDecreases plasma phosphate concentrationIncreases osteoclastic activity (increasing calcium and phosphate resorption from bone)Increases renal tubular reabsorption of calciumDecreases renal phosphate reabsorptionIncreases renal conversion of 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol (via stimulation of 1-alpha hydroxylase)Increases calcium and phosphate absorption in the small intestine (indirectly via increased 1,25-dihydroxycholecalciferol)
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 101
Correct
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Regarding the lacrimal apparatus, which of the following statements is CORRECT:
Your Answer: Lacrimal fluid is drained from the eyeball through the lacrimal punctum.
Explanation:Lacrimal fluid is drained from the eyeball through the lacrimal punctum.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 102
Correct
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Pancreatic ductal alkaline fluid secretion is mainly stimulated by which of the following hormones:
Your Answer: Secretin
Explanation:Pancreatic exocrine secretion is controlled by:Parasympathetic stimulation which enhances secretion of both the enzyme and aqueous componentsSympathetic stimulation which inhibits pancreatic secretionSecretin which stimulates secretion of the alkaline-rich fluid from ductal cellsCholecystokinin which stimulates secretion of the enzyme-rich fluid from acinar cellsSomatostatin which inhibits secretion from both acinar and ductal cellsGastrin which stimulates pancreatic acinar cells to secrete digestive enzymes
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 103
Correct
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An elderly patient presents to ED following a fall after feeling light headed when standing up. You are reviewing his medication and note that he is taking a high dose of furosemide. Loop diuretics act primarily at which of the following sites in the nephron:
Your Answer: Thick ascending limb
Explanation:Loop diuretics inhibit the Na+/K+/2Cl- symporter on the luminal membrane in the thick ascending limb of the loop of Henle, thus preventing reabsorption of NaCl and water. These agents reduce reabsorption of Cl- and Na+ and increase Ca2+ excretion and loss of K+ and Mg2+.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 104
Correct
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Adrenocorticotropic hormone release from the anterior pituitary is stimulated by which of the following:
Your Answer: Corticotropin-releasing hormone
Explanation:ACTH secretion is stimulated by corticotropin-releasing hormone (CRH) from the hypothalamus.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 105
Correct
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A 67-year-old woman arrives at the Emergency Department with chest pain. Flecainide is one of the medications she is taking.Which of the following statements about flecainide mechanism of action is correct?
Your Answer: Blocks Na+ channels in the heart
Explanation:Flecainide is an antiarrhythmic drug of class Ic that works by blocking the Nav1.5 sodium channel in the heart, prolonging the cardiac action potential and slowing cardiac impulse conduction. It has a significant impact on accessory pathway conduction, particularly retrograde conduction, and significantly reduces ventricular ectopic foci.Many different arrhythmias can be treated with flecainide, including:Pre-excitation syndromes (e.g. Wolff-Parkinson-White)Acute atrial arrhythmiasVentricular arrhythmiasChronic neuropathic painThe use of flecainide is contraindicated in the following situations:Abnormal left ventricular functionAtrial conduction defects (unless pacing rescue available)Bundle branch block (unless pacing rescue available)Distal block (unless pacing rescue available)Haemodynamically significant valvular heart diseaseHeart failureHistory of myocardial infarctionLong-standing atrial fibrillation where conversion to sinus rhythm not attemptedSecond-degree or greater AV block (unless pacing rescue available)Sinus node dysfunction (unless pacing rescue available)Flecainide should only be used in people who don’t have a structural heart problem. The CAST trial found a significant increase in sudden cardiac death and all-cause mortality in patients with an ejection fraction of less than 40% after a myocardial infarction, where it tended to be pro-arrhythmic.Anti-arrhythmic drugs have a limited and ineffective role in the treatment of atrial flutter. It’s important to keep in mind that flecainide shouldn’t be used by itself to treat atrial flutter. When used alone, there is a risk of inducing 1:1 atrioventricular conduction, which results in an increase in ventricular rate that is paradoxical. As a result, it should be used in conjunction with a beta-blocker or a calcium channel blocker with a rate-limiting effect.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 106
Correct
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Which of the following is NOT a typical side effect of opioid analgesics:
Your Answer: Diarrhoea
Explanation:All opioids have the potential to cause:Gastrointestinal effects – Nausea, vomiting, constipation, difficulty with micturition (urinary retention), biliary spasmCentral nervous system effects – Sedation, euphoria, respiratory depression, miosisCardiovascular effects – Peripheral vasodilation, postural hypotensionDependence and tolerance
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 107
Incorrect
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A 27-year-old man presents with a laceration of his forearm that severed the nerve that innervates flexor carpi radialis.Which of the following nerves has been damaged in this case? Select ONE answer only.
Your Answer: The radial nerve
Correct Answer: The median nerve
Explanation:Flexor carpi radialis is innervated by the median nerve.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 108
Correct
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Which of the following is NOT a typical clinical feature of diabetic ketoacidosis:
Your Answer: Cheyne–Stokes respiration
Explanation:Clinical features of DKA: Symptoms: Polyuria, polydipsia, thirst, lethargy, weight loss, nausea, vomiting, anorexia, abdominal pain, dehydration, headache, altered mental stateSigns: Dry mucous membranes, ketotic breath, tachycardia, hypotension, Kussmaul breathing, focal signs of precipitant e.g. infection
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 109
Incorrect
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A 25-year-old female arrives at the emergency room with a severe case of asthma. When she doesn't seem to be improving after initial treatment, you decide to start an aminophylline infusion.From the options below, which is Aminophylline's main mechanism of action?Â
Your Answer: Anti-muscarinic effects
Correct Answer: Phosphodiesterase inhibition
Explanation:Theophylline and Ethylenediamine are combined in a 2:1 ratio to form Aminophylline. Its solubility is improved by the addition of Ethylenediamine. It has a lower potency and a shorter duration of action than Theophylline.It is used to treat the following conditions: Heart failureIt is used to treat the following conditions: COPDBradycardiasAminophylline has the following properties:Phosphodiesterase inhibitor that increases intracellular cAMP and relaxes smooth muscle in the bronchial airways and pulmonary blood vessels.Mast cell stabilization is achieved by using a non-selective adenosine receptor antagonist.It has slight positive inotropic and chronotropic effects, increasing cardiac output and decreasing systemic vascular resistance, lowering arterial blood pressure. It has been used historically in the treatment of refractory heart failure and is indicated by the current ALS guidelines as a substitute treatment for bradycardia. The daily oral dose for adults is 900 mg, divided into 2-3 doses. For severe asthma or COPD, a loading dosage of 5 mg/kg over 10-20 minutes is given, followed by a continuous infusion of 0.5 mg/kg/hour. The therapeutic range is small (10-20 microgram/ml), hence assessments of aminophylline plasma concentrations are useful during long-term treatment.
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This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 110
Correct
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A 45-year old man presented to the emergency room with complains of chest pain and breathlessness. Upon history taking and examination, it was discovered that he had a right-sided spontaneous pneumothorax and had a failed attempt at pleural aspiration. The pneumothorax is still considerable in size, but he remains breathless. A Seldinger chest drain was inserted but it started to drain frank blood shortly after. Which of the following complications is most likely to have occurred?
Your Answer: Intercostal artery laceration
Explanation:Injury to the intercostal artery (ICA) is an infrequent but potentially life-threatening complication of all pleural interventions. Traditional anatomy teaching describes the ICA as lying in the intercostal groove, protected by the flange of the rib. This is the rationale behind the recommendation to insert needles just above the superior border of the rib. Current recommendations for chest drain insertion suggest that drains should be inserted in the ‘safe triangle’ in order to avoid the heart and the mediastinum and be above the level of the diaphragm. The safe triangle is formed anteriorly by the lateral border of the pectoralis major, laterally by the lateral border of the latissimus dorsi, inferiorly by the line of the fifth intercostal space and superiorly by the base of the axilla. Imaging guidance also aids in the safety of the procedure.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 111
Correct
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The following statements are not true of the flexor digiti minimi brevis, except?
Your Answer: It is situated on the radial border of abductor digiti minimi
Explanation:Flexor digiti minimi brevis muscle is located on the ulnar side of the palm, lying on the radial border of the abductor digiti minimi. Together with the abductor digiti minimi and opponens digiti minimi muscles, it forms the hypothenar eminence. The muscle is situated inferior and lateral to adductor digiti minimi muscle and superior and medial to opponens digiti minimi muscle. The proximal parts of flexor digiti minimi brevis and abductor digiti minimi muscles form a gap through which deep branches of the ulnar artery and ulnar nerve pass.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 112
Correct
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Regarding folate requirements, which of the following statements is CORRECT:
Your Answer: Dietary folate is found particularly in leafy green vegetables and liver.
Explanation:Megaloblastic anemia results from inhibition of DNA synthesis during red blood cell production. When DNA synthesis is impaired, the cell cycle cannot progress from the growth stage to the mitosis stage. This leads to continuing cell growth without division, which presents as macrocytosis, with an increase in mean corpuscular volume (MCV). The defect in red cell DNA synthesis is most often due to hypovitaminosis, specifically vitamin B12 deficiency or folate deficiency.Folate is an essential vitamin found in most foods, especially liver, green vegetables and yeast. The normal daily diet contains 200 – 250 μg, of which about 50% is absorbed. Daily adult requirements are about 100 μg. Absorption of folate is principally from the duodenum and jejunum. Stores of folate are normally only adequate for 4 months and so features of deficiency may be apparent after this time.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 113
Correct
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Which of the following terms describes the proportion of individuals with a negative test result who actually do not have a disease:
Your Answer: Negative predictive value
Explanation:Negative predictive value (NPV) is the proportion of individuals with a negative test result who do not have the disease.NPV = d/(c+d)
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 114
Incorrect
-
In the Kaplan-Meier plot, which of the following labels should be applied to the X-axis?
Your Answer: Number of study participants
Correct Answer: Time in years
Explanation:Kaplan-Meier estimate is one of the best options to be used to measure the fraction of subjects living for a certain amount of time after treatment. In clinical trials or community trials, the effect of an intervention is assessed by measuring the number of subjects survived or saved after that intervention over a period of time. The time starting from a defined point to the occurrence of a given event, for example death, is called as survival time and the analysis of group data as survival analysis. The graph plotted between estimated survival probabilities/estimated survival percentages (on Y axis) and time past after entry into the study (on X axis) consists of horizontal and vertical lines.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 115
Correct
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A 27-year-old athlete presents with buttock pain after tearing his gluteus maximus muscle.In which of the following nerves is the gluteus maximus muscle innervated by?
Your Answer: Inferior gluteal nerve
Explanation:The gluteal muscles are a group of muscles that make up the buttock area. These muscles include: gluteus maximus, gluteus medius. and gluteus minimus.The gluteus maximus is the most superficial as well as largest of the three muscles and makes up most of the shape and form of the buttock and hip area. It is a thick, fleshy muscle with a quadrangular shape. It is a large muscle and plays a prominent role in the maintenance of keeping the upper body erect.The innervation of the gluteus maximus muscle is from the inferior gluteal nerve.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 116
Correct
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Despite taking the oral contraceptive pill, a 29-year-old woman becomes pregnant. During a medication review, you discover that she is epileptic and that her antiepileptic therapy has recently been changed.Which of the following antiepileptics is most likely to impair the oral contraceptive pill's effectiveness?
Your Answer: Carbamazepine
Explanation:The metabolism of ethinyl oestradiol and progestogens has been shown to be increased by enzyme-inducing antiepileptics. The oral contraceptive pill (OCP) is less effective in preventing pregnancy as a result of this increased breakdown.Antiepileptic drugs that induce enzymes include:CarbamazepinePhenytoinPhenobarbitalTopiramateAntiepileptics that do not induce enzymes are unlikely to affect contraception. Non-enzyme-inducing anticonvulsants include the following:ClonazepamGabapentinLevetiracetamPiracetamSodium valproate is a type of valproate that is used toLamotrigine is an antiepileptic drug that does not cause the production of enzymes. It does, however, require special consideration, unlike other non-enzyme-inducing antiepileptics. The OCP does not appear to affect epilepsy directly, but it does appear to lower lamotrigine levels in the blood. This could result in a loss of seizure control and the occurrence of seizures.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 117
Correct
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The Frank-Starling curve is shifted downhill in heart failure due to which of the following?
Your Answer: Decrease in contractility
Explanation:The Frank–Starling mechanism states that the left ventricle can increase its force of contraction and hence stroke volume in response to increases in venous return and thus preload. Changes in afterload or inotropy cause the Frank–Starling curve to rise or fall. In heart failure, the Frank–Starling curve is shifted downward (flattened), requiring higher venous return and filling pressure to enhance contractility and stroke volume.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 118
Incorrect
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In the resus area of your Emergency Department, you are called to a VF cardiac arrest.During an adult VF arrest, which of the following points should be treated with adrenaline?
Your Answer: As soon as circulatory access is obtained
Correct Answer: After the 3 rd shock, once chest compressions have been resumed
Explanation:In non-shockable (PEA/asystole) cardiac arrests, adrenaline should be given as soon as circulatory access is gained. The dose is 1 mg via IV or IO (10 mL of 1:10,000 or 1 mL of 1:1000).Once chest compressions have been resumed after the third shock in a shockable (Vf/pVT) cardiac arrest, adrenaline should be administered. The dosage is one milligram (10 mL of 1:10,000 or 1 mL of 1:1000)It should be given every 3-5 minutes after that (i.e. alternate loops) and without interrupting chest compressions.Systemic vasoconstriction is caused by the alpha-adrenergic effects of adrenaline, which raises coronary and cerebral perfusion pressures.Adrenaline’s beta-adrenergic effects are inotropic (increased myocardial contractility) and chronotropic (increased heart rate), and they can increase coronary and cerebral blood flow. However, concomitant increases in myocardial oxygen consumption and ectopic ventricular arrhythmias (especially in the absence of acidaemia), transient hypoxemia due to pulmonary arteriovenous shunting, impaired microcirculation, and increased post-cardiac arrest myocardial dysfunction may offset these benefits.Although there is no evidence of long-term benefit from its use in cardiac arrest, the improved short-term survival reported in some studies justifies its use.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 119
Correct
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You investigated a patient with a chest infection and want to start antibiotics right away. The patient says they she can't take cephalosporins when you ask about allergies.Choose the 'second-generation' cephalosporin from the following choices?Â
Your Answer: Cefuroxime
Explanation:Cephalosporins of the first generation include cephalexin, cefradine, and cefadroxil. Urinary tract infections, respiratory tract infections, otitis media, and skin and soft-tissue infections are all treated with them.Second-generation cephalosporins include cefuroxime, cefaclor, and cefoxitin. These cephalosporins are less vulnerable to beta-lactamase inactivation than the ‘first-generation’ cephalosporins. As a result, they’re effective against germs that are resistant to other antibiotics, and they’re especially effective against Haemophilus influenzae.Cephalosporins of the third generation include cefotaxime, ceftazidime, and ceftriaxone. They are more effective against Gram-negative bacteria than second generation’ cephalosporins. They are, however, less effective against Gram-positive bacteria such Staphylococcus aureus than second-generation cephalosporins.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 120
Correct
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Question 121
Incorrect
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A 57-year-old male presents to the orthopaedic clinic complaining of pain and swelling in the left knee joint. On examination, the left knee is swollen, tender and erythematous. The patient is booked for joint aspiration, and a diagnosis of pseudogout is made following the aspiration. Which types of crystals would be seen in the joint aspirate to lead to this diagnosis?
Your Answer: Positively birefringent needle-shaped crystals
Correct Answer: Positively birefringent brick-shaped crystals
Explanation:Gout and pseudogout are both characterised by crystal deposition in the affected joints. The deposition of urate crystals causes gout, while calcium pyrophosphate crystals cause pseudogout. The crystals can be distinguished microscopically because urate crystals are negatively birefringent needle-shaped crystals, whilst calcium pyrophosphate crystals are positively birefringent brick-shaped crystals.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 122
Incorrect
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A 62-year-old woman has reduced urine output, nausea, and confusion. Renal function tests and other investigations done leads to a diagnosis of acute kidney injury (AKI).Which one of these is consistent with a diagnosis of AKI?
Your Answer: A 25% increase in serum creatinine within the preceding seven days
Correct Answer: A rise in serum creatinine of 30 μmol/L within 48 hours
Explanation:AKI is diagnosed based on an acutely rising serum creatinine and/or reduction in urine output.
AKI can often be non-oliguric.
AKI is present if any one or more of the following criteria is met:
- A rise in serum creatinine of ≥26 micromol/L (≥0.3 mg/dL) within 48 hours
- A rise in serum creatinine to ≥1.5 times baseline, which is known or presumed to have occurred within the past 7 days (in practice you can use the lowest value from the past 3 months as the baseline for the patient)
- Urine volume <0.5 ml/kg/hour for at least 6 hours.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 123
Correct
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Which one of the listed cells are typically found in a granuloma?
Your Answer: Epithelioid cells
Explanation:Typically, granuloma has Langhan’s cells (large multinucleated cells ) surrounded by epithelioid cell aggregates, T lymphocytes and fibroblasts.Antigen presenting monocytic cells found in the skin are known as Langerhan’s cells.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 124
Correct
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Which of the following blood groups is the least common in the UK:
Your Answer: AB
Explanation:Blood group O is the most common in the UK (46 %), followed by group A (42 %), group B (9 %) and finally group AB (3 %).Blood group O has no antigens, but both anti-A and anti-B antibodies and thus is the universal donor. Blood group AB has both A and B antigens but no antibodies and thus is the universal recipient.Blood group A has A antigens and anti-B antibodies and blood group B has B antigens and anti-A antibodies.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 125
Incorrect
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In adult advanced life support, which of the following best describes the correct administration of adrenaline for a non-shockable rhythm:
Your Answer: Give 1 mg of adrenaline after 2 minutes of compressions and every 3 - 5 minutes thereafter
Correct Answer: Give 1 mg of adrenaline as soon as intravenous access is achieved and every 3 - 5 minutes thereafter
Explanation:IV adrenaline 1 mg (10 mL of 1:10,000 solution) should be given after 3 shocks and every 3 – 5 minutes/after alternate shocks thereafter.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 126
Correct
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A patient is diagnosed as having a glucagonoma. Her blood serum glucagon concentration is 1246 pg/mL.Glucagon is produced in which of the following cells? Select ONE answer only.
Your Answer: Alpha-cells in the pancreas
Explanation:Glucagon is a peptide hormone that is produced and secreted by alpha cells of the islets of Langerhans, which are located in the endocrine portion of the pancreas. The main physiological role of glucagon is to stimulate hepatic glucose output, thereby leading to increases in glycaemia. It provides the major counter-regulatory mechanism to insulin in maintaining glucose homeostasis.Hypoglycaemia is the principal stimulus for the secretion of glucagon but may also be used as an antidote in beta-blocker overdose and in anaphylaxis in patients on beta-blockers that fail to respond to adrenaline. Glucagon then causes:GlycogenolysisGluconeogenesisLipolysis in adipose tissueThe secretion of glucagon is also stimulated by:AdrenalineCholecystokininArginineAlanineAcetylcholineThe secretion of glucagon is inhibited by:InsulinSomatostatinIncreased free fatty acidsIncreased urea productionGlycolysis is the metabolic pathway that converts glucose into pyruvate. The free energy released by this process is used to form ATP and NADH. Glycolysis is inhibited by glucagon, and glycolysis and gluconeogenesis are reciprocally regulated so that when one cell pathway is activated, the other is inactive and vice versa.Glucagon has a minor effect of enhancing lipolysis in adipose tissue. Lipolysis is the breakdown of lipids and involves the hydrolysis of triglycerides into glycerol and free fatty acids. It makes fatty acids available for oxidation.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 127
Incorrect
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One of your patients has been infected by an obligate pathogen and presents with features of this condition.Which of these is an example of an obligate pathogen?
Your Answer: Pneumocystis jiroveci
Correct Answer: Trepenoma pallidum
Explanation:Treponema pallidum is an obligate pathogen. Obligate pathogens are almost always associated with disease and usually cannot survive outside of the body for long periods of time. Examples include and HIV.Staphylococcus aureus and Bacteroides fragilis are conditional pathogens. These are pathogens that usually cause disease only if certain conditions are met.Pneumocystis jiroveci and Pseudomonas aeruginosa, are opportunistic pathogens. These are pathogens that can only cause disease in an immunocompromised host or under unusual circumstances.
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 128
Correct
-
The cutaneous circulation's principal role is thermoregulation. This process is aided by the existence of arteriovenous anastomoses.Which of the following anatomical areas has the greatest number of arteriovenous anastomoses?Â
Your Answer: Pinna of the ear
Explanation:Short vessels called arteriovenous anastomoses (AVAs) link tiny arteries and veins. They have a large lumen diameter. The strong and muscular walls allow AVAs to completely clog the vascular lumen, preventing blood flow from artery to vein (acting like a sphincter). When the AVAs open, they create a low-resistance connection between arteries and veins, allowing blood to flow into the limbs’ superficial venous plexuses. There is no diffusion of solutes or fluid into the interstitium due to their strong muscle walls.AVAs are densely innervated by adrenergic fibres from the hypothalamic temperature-regulation centre. High sympathetic output occurs at normal core temperatures, inducing vasoconstriction of the AVAs and blood flow through the capillary networks and deep plexuses. When the temperature rises, sympathetic output decreases, producing AVA vasodilation and blood shunting from the artery to the superficial venous plexus. Heat is lost to the environment as hot blood rushes near to the skin’s surface.AVAs are a specialized anatomical adaptation that can only be found in large quantities in the fingers, palms, soles, lips, and pinna of the ear.
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This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
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Question 129
Incorrect
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A 55-year-old woman with a known history of bronchiectasis has lung function testing carried out and is found to have significant airways obstruction.Which of the following lung volumes or capacities is LEAST likely to be decreased in this case? Select ONE answer only.
Your Answer: Inspiratory reserve volume
Correct Answer: Functional residual capacity
Explanation:Obstructive lung disorders are characterised by airway obstruction. Many obstructive diseases of the lung result from narrowing of the smaller bronchi and larger bronchioles, often because of excessive contraction of the smooth muscle itself.In obstructive lung disease, FEV1is reduced to <80% of normal and FVC is usually reduced but to a lesser extent than FEV1. The FEV1/FVC ratio is reduced to 80% in the presence of symptomsModerate airflow obstruction = FEV1of 50-79%Severe airflow obstruction = FEV1of 30-49%Very severe airflow obstruction = FEV1<30%.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 130
Correct
-
The 'bucket handle' movement of the thoracic wall describes which of the following movements:
Your Answer: The middles of the shafts of the ribs moving upwards and laterally
Explanation:Because the middles of the shafts of the ribs are lower than either the anterior or posterior end, elevation of the ribs also moves the middles of the shafts laterally. This ‘bucket handle’ upwards and lateral movement increases the lateral dimensions of the thorax.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 131
Correct
-
Which of the following statements about neutrophils is TRUE:
Your Answer: Neutrophils are typically the first immune cell to arrive to a site of injury.
Explanation:Neutrophils are the most numerous peripheral blood leukocytes, accounting for 50-70 percent of all circulating white cells. Neutrophils have a compact nucleus with two to five lobes and a pale cytoplasm with an irregular shape containing numerous fine pink-blue or grey-blue granules. The granules are classified as primary, which emerges during the promyelocyte stage, and secondary, which develop at the myelocyte stage and predominate in the mature nucleus.The lifespan of neutrophils in the blood is only 6 – 10 hours. In response to tissue damage, cytokines and complement proteins, neutrophils migrate from the bloodstream to the site of insult within minutes, where they destroy pathogens by phagocytosis.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 132
Correct
-
How is measles primarily transmitted:
Your Answer: Respiratory droplet route
Explanation:Measles belongs to the paramyxoviridae group of viruses. The incubation period is 7-18 days (average 10) and it is spread by airborne or droplet transmission. The classical presentation is of a high fever with coryzal symptoms and photophobia with conjunctivitis often being present. The rash that is associated is a widespread erythematous maculopapular rash. Koplik spots are pathognomonic for measles, and are the presence of white lesions on the buccal mucosa.Differential diagnoses would include:RubellaRoseola infantum (exanthem subitom)Scarlet feverKawasaki diseaseErythema infectiosum (5thdisease)EnterovirusInfectious mononucleosisDiagnosis can be confirmed by the following means:Salivary swab for measles specific IgMSerum sample for measles specific IgMSalivary swab for RNA detectionPossible complications include:Otitis mediaFebrile convulsionsPneumoniaBronchiectasisDiarrhoeaMeningitisEncephalitisImmunosuppressionSubacute sclerosing panencephalitisDeath
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 133
Correct
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A 40-year-old man who has a history of asthma arrives at the emergency department complaining of palpitations that have been going on for 5 days. Which of the following beta-blockers is the safest for an asthmatic patient?
Your Answer: Atenolol
Explanation:Atenolol is a beta blocker, which is a type of medication that works by preventing certain natural substances in the body, such as epinephrine, from acting on the heart and blood vessels. This effect reduces heart rate, blood pressure, and cardiac strain. Atenolol, bisoprolol fumarate, metoprolol tartrate, nebivolol, and (to a lesser extent) acebutolol have a lower action on beta2 (bronchial) receptors and are thus cardio selective but not cardiac specific. They have a lower effect on airway resistance, although they are not without this adverse effect.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 134
Correct
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A 29-year-old female with chronic anaemia secondary to sickle cell disease is being transfused. A few minutes after starting the blood transfusion, she develops widespread itching with urticarial rash, wheezing, nausea and chest pain. Her BP reduces to 60/40 mmHg.What is the most appropriate treatment?
Your Answer: Stop the transfusion and administer adrenaline
Explanation:Anaphylaxis transfusion reaction occurs when an individual has previously been sensitized to an allergen present in the blood and, on re-exposure, releases IgE or IgG antibodies. Patients with anaphylaxis usually develop laryngospasm, bronchospasm, abdominal pain, nausea, vomiting, hypotension, shock, and loss of consciousness. The transfusion should be stopped immediately and the patient should be treated with adrenaline, oxygen, corticosteroids, and antihistamines.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 135
Correct
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Question 136
Correct
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Question 137
Correct
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Which of the following clinical features is most suggestive of a lesion of the occipital lobe:
Your Answer: Homonymous hemianopia
Explanation:Homonymous hemianopia is a visual field defect involving either the two right or the two left halves of the visual fields of both eyes. It is caused by lesions of the retrochiasmal visual pathways, ie, lesions of the optic tract, the lateral geniculate nucleus, the optic radiations, and the cerebral visual (occipital) cortex
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 138
Correct
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A patient presents with an adducted eye at rest which cannot abduct past the midline, which of the following cranial nerves is most likely to be affected:
Your Answer: Abducens nerve
Explanation:Abducens nerve palsies result in a convergent squint at rest (eye turned inwards) with inability to abduct the eye because of unopposed action of the rectus medialis. The patient complains of horizontal diplopia when looking towards the affected side. With complete paralysis, the eye cannot abduct past the midline.
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This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
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Question 139
Correct
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An injury to the brachial plexus can cause Erb's palsy. The following is expected to happen to a patient suffering from this condition, except for which one:
Your Answer: Weakness of medial rotation of the arm
Explanation:Erb’s palsy can be caused by a traumatic force downward on the upper arm and shoulder that damages the upper root of the brachial plexus. The patient will lose shoulder abduction (deltoid, supraspinatus), shoulder external rotation (infraspinatus), and elbow flexion as a result of this condition (biceps, brachialis).
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 140
Correct
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Which of the following movements is controlled by the pectoralis major muscle?
Your Answer: Flexion, adduction and medial rotation of the humerus
Explanation:The pectoralis major is a muscle that runs across the top of the chest and connects to a ridge on the back of the humerus (the bone of the upper arm). Adduction, or lowering, of the arm (opposed to the deltoideus muscle) and rotation of the arm forward around the axis of the body are two of its main functions.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 141
Correct
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Which coronary artery is mostly likely affected if an ECG shows ST segment elevation in leads II, III and aVF, and ST segment depression in V1-V3?
Your Answer: Right coronary artery
Explanation:A posterior wall MI occurs when posterior myocardial tissue (now termed inferobasilar), usually supplied by the posterior descending artery — a branch of the right coronary artery in 80% of individuals — acutely loses blood supply due to intracoronary thrombosis in that vessel. This frequently coincides with an inferior wall MI due to the shared blood supply.The ECG findings of an acute posterior wall MI include the following:1. ST segment depression (not elevation) in the septal and anterior precordial leads (V1-V4). This occurs because these ECG leads will see the MI backwards; the leads are placed anteriorly, but the myocardial injury is posterior.2. A R/S wave ratio greater than 1 in leads V1 or V2.3. ST elevation in the posterior leads of a posterior ECG (leads V7-V9). Suspicion for a posterior MI must remain high, especially if inferior ST segment elevation is also present.4. ST segment elevation in the inferior leads (II, III and aVF) if an inferior MI is also present.The following ECG leads determine the location and vessels involved in myocardial infarction:ECG Leads Location Vessel involvedV1-V2 Septal wall Left anterior descendingV3-V4 Anterior wall Left anterior descendingV5-V6 Lateral wall Left circumflex arteryII, III, aVF Inferior wall Right coronary artery (80%) or Left circumflex artery (20%)I, aVL High lateral wall Left circumflex arteryV1, V4R Right ventricle Right coronary arteryV7-V9 Posterior wall Right coronary artery
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 142
Correct
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A 64-year-old woman with a history of chronic breathlessness is referred for lung function testing.Which of the following statements regarding lung function testing is FALSE? Select ONE answer only.
Your Answer: In restrictive lung disease, the FVC is increased
Explanation:In restrictive lung disorders there is a reduction in the forced vital capacity (FVC) and the forced expiratory volume in one second (FEV1). The decline in the FVC is greater than that of the FEV1, resulting in preservation of the FEV1/FVC ratio (>0.7%).In obstructive lung disease, FEV1is reduced to <80% of normal and FVC is usually reduced but to a lesser extent than FEV1. The FEV1/FVC ratio is reduced to 80% in the presence of symptomsModerate airflow obstruction = FEV1 of 50-79%Severe airflow obstruction = FEV1 of 30-49%Very severe airflow obstruction = FEV1<30%.Spirometry is a poor predictor of durability and quality of life in COPD but can be used as part of the assessment of severity.COPD can only be diagnosed on spirometry if the FEV1 is <80% and FEV1/FVC ratio is < 0.7.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 143
Incorrect
-
Which of the following risk ratios indicates no difference in risk between two groups:
Your Answer: 0
Correct Answer: 1
Explanation:A risk ratio of 1 indicates no difference in risk between groups.If the risk ratio of an event is > 1, the rate of that event is increased in the exposed group compared to the control group.If the risk ratio is < 1, the rate of that event is reduced in the exposed group compared to the control group.
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 144
Correct
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A 67-year-old woman complains of general malaise, nausea, and vomiting. She is perplexed and declares that everything 'looks yellow.' Her potassium level is 6.8 mmol/l, according to a blood test.Which of the drugs listed below is most likely to be the cause of her symptoms?
Your Answer: Digoxin
Explanation:Because digoxin has a narrow therapeutic index, it can cause toxicity both during long-term therapy and after an overdose. Even when the serum digoxin concentration is within the therapeutic range, it can happen.Acute digoxin toxicity usually manifests itself within 2-4 hours of an overdose, with serum levels peaking around 6 hours after ingestion and life-threatening cardiovascular complications following 8-12 hours.Chronic digoxin toxicity is most common in the elderly or those with impaired renal function, and it is often caused by a coexisting illness. The clinical signs and symptoms usually appear gradually over days to weeks.The following are characteristics of digoxin toxicity:Nausea and vomitingDiarrhoeaAbdominal painConfusionTachyarrhythmias or bradyarrhythmiasXanthopsia (yellow-green vision)Hyperkalaemia (early sign of significant toxicity)Some precipitating factors are as follows:Elderly patientsRenal failureMyocardial ischaemiaHypokalaemiaHypomagnesaemiaHypercalcaemiaHypernatraemiaAcidosisHypothyroidismSpironolactoneAmiodaroneQuinidineVerapamilDiltiazem
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 145
Correct
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Question 146
Correct
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A 70-year-old patient is diagnosed with Cushing's disease. She has a history of weight gain, hypertension, and easy bruising.In this patient, which of the following is the MOST LIKELY UNDERLYING CAUSE?
Your Answer: Pituitary adenoma
Explanation:Cushing’s syndrome is a collection of symptoms and signs caused by prolonged exposure to elevated levels of either endogenous or exogenous glucocorticoids.The most common cause of Cushing’s syndrome is the iatrogenic administration of corticosteroids. The second most common cause of Cushing’s syndrome is Cushing’s disease.Cushing’s disease should be distinguished from Cushing’s syndrome and refers to one specific cause of the syndrome, an adenoma of the pituitary gland that secretes large amounts of ACTH and, in turn, elevates cortisol levels. This patient has a diagnosis of Cushing’s disease, and this is, therefore, the underlying cause in this case.The endogenous causes of Cushing’s syndrome include:Pituitary adenoma (Cushing’s disease)Ectopic corticotropin syndrome, e.g. small cell carcinoma of the lungAdrenal hyperplasiaAdrenal adenomaAdrenal carcinoma
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 147
Correct
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Regarding bicarbonate handling by the proximal tubule, which of the following statements is CORRECT:
Your Answer: For each H + secreted into the lumen, one Na + and one HCO 3 - is reabsorbed into the plasma.
Explanation:About 80% of bicarbonate is reabsorbed in the proximal tubule. HCO3-is not transported directly, tubular HCO3-associates with H+secreted by epithelial Na+/H+antiporters to form carbonic acid (H2CO3) which readily dissociates to form carbon dioxide and water in the presence of carbonic anhydrase. CO2and water diffuse into the tubular cells, where they recombine to form carbonic acid which dissociates to H+and HCO3-. This HCO3-is transported into the interstitium largely by Na+/HCO3-symporters on the basolateral membrane (and H+is secreted back into the lumen). For each H+secreted into the lumen, one Na+and one HCO3-are reabsorbed into the plasma. H+is recycled so there is little net secretion of H+at this stage.
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This question is part of the following fields:
- Physiology
- Renal
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Question 148
Incorrect
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Which of the following is NOT a common side effect of amiodarone:
Your Answer: Slate grey skin discolouration
Correct Answer: Blue/green teeth discolouration
Explanation:Common side effects of amiodarone include: Bradycardia, Nausea and vomiting, Thyroid disorders – hypothyroidism and hyperthyroidism, Persistent slate grey skin discoloration, Photosensitivity, Pulmonary toxicity (including pneumonitis and fibrosis), Hepatotoxicity, Corneal microdeposits (sometimes with night glare), Peripheral neuropathy and Sleep disorders.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 149
Correct
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A 36-year-old man who works in a farm presents with a deep laceration over the palm of his hand. A median nerve block was performed at his wrist to facilitate wound exploration and closure.Which of the following statements regarding median nerve blocks at the wrist is considered correct?
Your Answer: The needle should be inserted approximately 2.5 cm proximal to flexor retinaculum
Explanation:A median nerve block is a simple, safe, and effective method of obtaining anaesthesia to the palmar aspect of the thumb, index finger, middle finger, radial portion of the palm and ring finger. The median nerve lies deep to the flexor retinaculum and about one centimetre under the skin of the volar wrist.The palmaris longus tendon lies superficial to the retinaculum and is absent in up to 20% of patients.The median nerve is located slightly lateral (radial) to the palmaris longus tendon and medial (ulnar) to the flexor carpi radialis tendon.The procedure is as follows:- Check sensation and motor function of the median nerve. Wear gloves and use appropriate barrier precautions.- Locate the flexor carpi radialis and palmaris longus tendons, which become prominent when the patient flexes the wrist against resistance. The palmaris longus tendon is usually the more prominent of the two tendons.- Needle-entry site: The needle will be inserted adjacent to the radial (lateral) border of the palmaris longus tendon just proximal to the proximal wrist crease. If the palmaris longus tendon is absent, the needle-entry site is about 1 cm ulnar to the flexor carpi radialis tendon.- Cleanse the site with antiseptic solution. Place a skin wheal of anaesthetic, if one is being used, at the needle-entry site.- Insert the needle perpendicularly through the skin and advance it slowly until a slight pop is felt as the needle penetrates the flexor retinaculum. When paraesthesia in the distribution of the median nerve confirms proper needle placement, withdraw the needle 1 to 2 mm.- Aspirate to exclude intravascular placement and then slowly (i.e., over 30 to 60 seconds) inject about 3 mL of anaesthetic. If the patient does not feel paraesthesia, redirect the needle in an ulnar direction, under the palmaris longus tendon. If paraesthesia is still not felt, slowly inject 3 to 5 mL of anaesthetic in the proximity of the nerve 1 cm deep to the tendon.- Allow about 5 to 10 minutes for the anaesthetic to take effect.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 150
Correct
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After a work-related accident, a 33-year old male is taken to the emergency room with difficulty in adduction and flexion of his left arm at the glenohumeral joint. The attending physician is suspects involvement of the coracobrachialis muscle.The nerve injured in the case above is?
Your Answer: The musculocutaneous nerve
Explanation:The coracobrachialis muscle is innervated by the musculocutaneous nerve (C5-C7) a branch of the lateral cord of the brachial plexus.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 151
Correct
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An outbreak of acute pneumonia occurs in military recruits living in one barrack and only in those persons located near the air conditioner. Epidemiologic surveillance results in isolation of the causal organism from the patients and from the drip pans of the air conditioner. The organism is weakly Gram-negative. The most likely organism is:
Your Answer: Legionella pneumophila
Explanation:Legionella pneumophilais a Gram negative bacterium that is found in natural water supplies and in the soil, transmitted predominantly via inhalation of aerosols generated from contaminated water (direct person-to-person spread of infected patients does not occur). It is the cause of Legionnaires’ disease. Outbreaks of Legionnaires’ disease have been linked to poorly maintained air conditioning systems, whirlpool spas and hot tubs.The clinical features of the pneumonic form of Legionnaires’ disease include:Mild flu-like prodrome for 1-3 daysCough (usually non-productive and occurs in approximately 90%)Pleuritic chest painHaemoptysisHeadacheNausea, vomiting and diarrhoeaAnorexiaLegionella pneumophilainfections can be successfully treated with macrolide antibiotics, such as erythromycin, or quinolones, such as ciprofloxacin. Tetracyclines, such as doxycycline, can also be used.The syndrome of inappropriate antidiuretic hormone secretion (SIADH) can occur with Legionnaires’ disease and will result in hyponatraemia as is seen in this case.Legionella pneumophilainfections are resistant to amoxicillin but can be successfully treated with macrolide antibiotics, such as erythromycin, or quinolones, such as ciprofloxacin. Tetracyclines, such as doxycycline, can also be used. The majority of cases of Legionnaires’ disease are caused by Legionella pneumophila, however many other species of Legionella have been identified.Legionella longbeachae is another less commonly encountered species that has also been implicated in outbreaks. It is predominantly found in soil and potting compost, and has caused outbreaks of Pontiac fever, the non-respiratory and less severe variant of Legionnaires’ disease.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 152
Incorrect
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Which of the following statements is incorrect regarding the electron transfer system?
Your Answer: The electron transfer system results in the production of water.
Correct Answer: The electron transfer system occurs in anaerobic respiration.
Explanation:The electron transfer system is responsible for most of the energy produced during respiration. The is a system of hydrogen carriers located in the inner mitochondrial membrane. Hydrogen is transferred to the electron transfer system via the NADH2molecules produced during glycolysis and the Krebs cycle. As a result, a H+ion gradient is generated across the inner membrane which drives ATP synthase. The final hydrogen acceptor is oxygen and the H+ions and O2 combine to form water.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 153
Correct
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A 34-year-old male is brought into the Emergency Department by the paramedics after a road traffic accident. After a quick triage, you establish that he will need to be intubated, and you ask for some ketamine to be prepared. Which one of the following options regarding this drug is true?
Your Answer: It is the only anaesthetic agent available that has analgesic, hypnotic, and amnesic properties
Explanation:Ketamine is a dissociative anaesthetic with analgesic, amnesic, and hypnotic effects. It is the only anaesthetic agent which causes all three of these effects.Ketamine exerts its action by non-competitive antagonism at the NMDA (N-methyl-D-aspartate) receptor. Due to its analgesic property, Ketamine is given so that patients do not retain memories of short term procedures. Ketamine is used for the induction and maintenance of anaesthesia in general surgery and for treating burn wounds, battlefield injuries, and children who cannot tolerate other anaesthetic or analgesic agents.It can be given by both intravenous and intramuscular routes. Ketamine causes cardiac stimulation by increasing the sympathetic tone. The major side effect is increased intracranial pressure as an increase in the sympathetic tone causes vasoconstriction and an increase in the MAP.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 154
Correct
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Capillaries are designed with a small diffusion distance for nutrition and gaseous exchange with the tissues they serve. Capillaries come in a variety of shapes and sizes, each with its own function in transcapillary exchange.Which of the following types of capillaries is the least permeable in the human body?
Your Answer: Continuous capillaries
Explanation:Capillaries are designed with a small diffusion distance for nutrition and gaseous exchange with the tissues they serve. Because oxygen and carbon dioxide are both highly soluble in lipids (lipophilic), they can easily diffuse along a concentration gradient across the endothelial lipid bilayer membrane. In contrast, glucose, electrolytes, and other polar, charged molecules are lipid-insoluble (hydrophilic). These chemicals are unable to pass through the lipid bilayer membrane directly and must instead travel through gaps between endothelial cells.Capillaries are divided into three types: continuous, fenestrated, and sinusoidal. Each of these capillary types contains different sized gaps between the endothelial cells that operate as a filter, limiting which molecules and structures can pass through.The permeability of capillaries is affected by the wall continuity, which varies depending on the capillary type.Skeletal muscle, myocardium, skin, lungs, and connective tissue all have continuous capillaries. These capillaries are the least permeable. They have a basement membrane and a continuous layer of endothelium. The presence of intercellular spaces allows water and hydrophilic molecules to pass across. Tight connections between the cells and the glycocalyx inhibit passage via these gaps, making diffusion 1000-10,000 times slower than for lipophilic compounds. The diffusion of molecules larger than 10,000 Da, such as plasma proteins, is likewise prevented by this narrow pore system. These big substances can pass through the capillary wall, but only very slowly, because endothelial cells have enormous holes.The kidneys, gut, and exocrine and endocrine glands all have fenestrated capillaries. These are specialized capillaries that allow fluid to be filtered quickly. Water, nutrients, and hormones can pass via windows or fenestrae in their endothelium, which are connected by a thin porous membrane. They are ten times more permeable than continuous capillaries due to the presence of these fenestrae. Fenestrated capillaries have a healthy basement membrane.The spleen, liver, and bone marrow all have sinusoidal capillaries, also known as discontinuous capillaries. Their endothelium has huge gaps of >100 nm, and their basement membrane is inadequate. They are highly permeable as a result, allowing red blood cells to travel freely.
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This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
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Question 155
Incorrect
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A 25-year old male is brought to the emergency room after a traffic accident. Upon examination, there was tenderness and erythema on the right acromioclavicular joint, with notable step deformity. On radiographic imaging, there is a superior elevation of the clavicle, a twice than normal coracoclavicular distance, and absence of fracture.Which of the following structure/s is/are likely to have ruptured?
Your Answer: Acromioclavicular ligament only
Correct Answer: Acromioclavicular ligament, coracoclavicular ligament and joint capsule
Explanation:Acromioclavicular joint injuries account for more than forty percent of all shoulder injuries. Mild injuries are not associated with any significant morbidity, but severe injuries can lead to significant loss of strength and function of the shoulder. Acromioclavicular injuries may be associated with a fractured clavicle, impingement syndromes, and more rarely neurovascular insults.The AC joint is a diarthrodial joint defined by the lateral process of the clavicle articulating with the acromion process as it projects anteriorly off the scapula. The joint is primarily stabilized by the acromioclavicular ligament, which is composed of an anterior, posterior, inferior, and superior component. Of note, the superior portion of the AC ligament is the most important component for the stability of the AC joint. Supporting structures include two coracoclavicular ligaments (trapezoid and conoid ligaments), which provide vertical stability, as well as the coracoacromial ligament.Patients with an AC joint injury typically present with anterosuperior shoulder pain and will describe a mechanism of injury of blunt trauma to the abducted shoulder or landing on an outstretched arm, suggestive of this type of injury. They may describe pain radiating to the neck or shoulder, which is often worse with movement or when they try to sleep on the affected shoulder. On examination, the clinician may observe swelling, bruising, or a deformity of the AC joint, depending on the degree of injury. The patient will be tender at that location. They may have a restriction in the active and passive range of motion secondary to pain. Piano key sign may be seen, with an elevation of the clavicle that rebounds after inferior compression.Standard X-rays are adequate to make a diagnosis of acromioclavicular joint injury and should be used to evaluate for other causes of traumatic shoulder pain.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 156
Correct
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A 22-year-old student presents with severe headache accompanied with nausea and vomiting. Upon observation and examination, it was noted that he is febrile and Kernig's sign is positive. A diagnosis of meningitis was suspected and a lumbar puncture was to be performed.Which of the following statements regarding meningitis is true?
Your Answer: The dura mater is the outermost layer
Explanation:Meningitis is defined as the inflammation of the meninges due to an infection caused by a bacteria or a virus. Symptoms usually include stiffness of the neck, headache, and fever. There are 3 meningeal layers that surround the spinal cord and they are the dura mater, arachnoid matter, and pia mater. The dura mater is the outermost and thickest layer out of all the 3 layers. The arachnoid atter is the middle layer, and is very thin.The third and deepest meningeal layer is the pia mater that is bound tightly to the surface of the spinal cord.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 157
Correct
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Which lobe of the prostate gland is most commonly affected in benign prostatic hypertrophy?
Your Answer: Median
Explanation:Benign enlargement of the prostate is common in men older than 50 years. The cause is possibly an imbalance in the hormonal control of the gland. The median lobe of the gland enlarges upward and encroaches within the sphincter vesicae, located at the neck of the bladder. The leakage of urine into the prostatic urethra causes an intense reflex desire to micturate. The enlargement of the median and lateral lobes of the gland produces elongation and lateral compression and distortion of the urethra so that the patient experiences difficulty in passing urine and the stream is weak. Back-pressure effects on the ureters and both kidneys are a common complication. The enlargement of the uvula vesicae (owing to the enlarged median lobe) results in the formation of a pouch of stagnant urine behind the urethral orifice within the bladder. The stagnant urine frequently becomes infected, and the inflamed bladder (cystitis) adds to the patient’s symptoms.In all operations on the prostate, the surgeon regards the prostatic venous plexus with respect. The veins have thin walls, are valveless, and are drained by several large trunks directly into the internal iliac veins. Damage to these veins can result in a severe haemorrhage.
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This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 158
Correct
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A 59-year-old man is complaining of pain in his perineal area, a recent onset of urinary frequency and urgency, fever, chills, and muscle aches. He has a long history of nocturia and terminal dribbling. On rectal examination you find an exquisitely tender prostate.Which of these antibacterial agents would be most appropriate in this case?
Your Answer: Ciprofloxacin for 14 days
Explanation:An acute focal or diffuse suppurative inflammation of the prostate gland is called acute bacterial prostatitis.According to the National Institute for Health and Care Excellence (NICE), acute prostatitis should be suspected in a man presenting with:A feverish illness of sudden onset which may be associated with rigors, arthralgia, or myalgia; Irritative urinary voiding symptoms; acute urinary retention; perineal or suprapubic pain and an exquisitely tender prostate on rectal examination.Treatment of acute prostatitis as recommended by NICE and the BNFare:Ciprofloxacin or ofloxacin for 14 daysAlternatively, trimethoprim can be used. Duration of treatment is still 14 days
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 159
Correct
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Regarding inhaled corticosteroids, which of the following statements is INCORRECT:
Your Answer: Lower doses of inhaled corticosteroids may be required in smokers.
Explanation:Current and previous smoking reduces the effectiveness of inhaled corticosteroids and higher doses may be necessary.
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 160
Incorrect
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Which of these immunoglobulin molecules can cross the placenta?
Your Answer: IgM and IgG
Correct Answer: IgG
Explanation:An important mechanism that provides protection to the foetus is placental transfer of maternal IgG antibodies while his/her humoral response is inefficient. The only antibody class that significantly crosses the human placenta is IgG.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 161
Incorrect
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A 30-year-old man bought into the ED with increased thirst, confusion, abdominal pain and constipation is suspected to have hypercalcaemia.What is the commonest cause of hypercalcaemia in the UK?
Your Answer: Malignancy
Correct Answer: Primary hyperparathyroidism
Explanation:The commonest cause of hypercalcaemia in the UK is primary hyperparathyroidism, which accounts for around 70-80% of cases. It is commoner in younger patients and in community setting.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 162
Correct
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A 27-year-old man has been diagnosed with testicular cancer and has spread to the regional lymph nodes. The lymph from the testes will drain to which of the following nodes?
Your Answer: Para-aortic lymph nodes
Explanation:Testes are retroperitoneal organs and its lymphatic drainage is to the lumbar and para-aortic nodes along the lumbar vertebrae.The scrotum is the one which drains into the nearby superficial inguinal nodes.The glans penis and clitoris drains into the deep inguinal lymph nodes.
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This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 163
Incorrect
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Which of the following factors decreases insulin secretion:
Your Answer: Glucagon
Correct Answer: Catecholamines
Explanation:Factors that increase insulin secretion:↑ Blood glucose↑ Amino acids↑ Fatty acidsGlucagonSecretinAcetylcholineFactors that decrease insulin secretion:↓ Blood glucoseSomatostatinCatecholamines
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 164
Incorrect
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A 50-year-old man presents with headaches, lethargy, hypertension, and electrolyte disturbance. A diagnosis of primary hyperaldosteronism is made.Which biochemical pictures would best support this diagnosis?
Your Answer: Hyperkalaemic metabolic acidosis
Correct Answer: Hypokalaemic metabolic alkalosis
Explanation:When there are excessive levels of aldosterone outside of the renin-angiotensin axis, primary hyperaldosteronism occurs. High renin levels will lead to secondary hyperaldosteronism. The classical presentation of hyperaldosteronism when symptoms are present include:HypokalaemiaMetabolic alkalosisHypertensionNormal or slightly raised sodium levels
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 165
Incorrect
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You undertake a medication review for a patient on the Clinical Decision Unit. Among the drugs he is currently taking is simvastatin.Which of the following side effects is he LEAST likely to have developed? Select ONE answer only.
Your Answer: Cerebral ischaemia
Correct Answer: Syncope
Explanation:Nitrates are used in the treatment of angina pectoris and the prevention of myocardial ischaemia. Commonly used examples of nitrates are glyceryl trinitrate and isosorbide dinitrate. Unwanted effects, however, are common and can limit therapy, particularly when angina is severe or when patients are unusually sensitive to the effects of nitrates.The following are common or very common side effects of nitratesArrhythmiasAstheniaCerebral ischaemiaDizzinessDrowsinessFlushingHeadacheHypotensionNausea and vomitingDiarrhoea, syncope and cyanosis can occur, but these are rare side effects. Dry eyes, bradycardia and metabolic acidosis have not been reported.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 166
Incorrect
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A 56-year-old female visits her cardiologist complaining of a condition that has started since he started her on amiodarone for atrial arrhythmia. The cardiologist recognised that she is experiencing a side effect of amiodarone. Which one of the following conditions will this woman NOT have?
Your Answer: Peripheral neuropathy
Correct Answer: Xanthopsia
Explanation:Amiodarone is a class III potassium channel blocker used to treat multiple types of arrhythmias. Side effects include:1. pulmonary fibrosis2. blue discolouration of the skin3. phototoxicity4. corneal deposits5. hepatic necrosis6. thyroid dysfunction7. sleep disturbances8. peripheral neuropathy. Xanthopsia is a condition where the patient complains of seeing yellow lines and is seen in digoxin overdose.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 167
Incorrect
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What is the main mechanism of action of dopamine as an inotropic sympathomimetic:
Your Answer: Dopamine receptor agonist
Correct Answer: Beta1-receptor agonist
Explanation:Dopamine is a neurotransmitter and a metabolic precursor of the catecholamines. It acts on beta1-receptors in cardiac muscle increasing cardiac contractility, and increases renal perfusion by stimulating dopamine receptors in the renal vasculature. This is of benefit in cardiogenic shock where deterioration of renal function is common.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 168
Correct
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Contraction of the diaphragm results in which of the following effects:
Your Answer: Increased vertical dimension of the thorax
Explanation:Contraction of the diaphragm (as in inspiration) results in flattening (depression) of the diaphragm with an increase in vertical dimension of the thorax. This results in decreased intrathoracic pressure and increased intra-abdominal pressure.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 169
Correct
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You are seeing a child with known mitochondrial disease who has presented breathlessness and cough. Which of the following best describes the function of mitochondria:
Your Answer: Energy production
Explanation:Mitochondria are membrane-bound organelles that are responsible for the production of the cell’s supply of chemical energy. This is achieved by using molecular oxygen to utilise sugar and small fatty acid molecules to generate adenosine triphosphate (ATP). This process is known as oxidative phosphorylation and requires an enzyme called ATP synthase. ATP acts as an energy-carrying molecule and releases the energy in situations when it is required to fuel cellular processes. Mitochondria are also involved in other cellular processes, including Ca2+homeostasis and signalling. Mitochondria contain a small amount of maternal DNA.Mitochondria have two phospholipid bilayers, an outer membrane and an inner membrane. The inner membrane is intricately folded inwards to form numerous layers called cristae. The cristae contain specialised membrane proteins that enable the mitochondria to synthesise ATP. Between the two membranes lies the intermembrane space, which stores large proteins that are required for cellular respiration. Within the inner membrane is the perimitochondrial space, which contains a jelly-like matrix. This matrix contains a large quantity of ATP synthase.Mitochondrial disease, or mitochondrial disorder, refers to a group of disorders that affect the mitochondria. When the number or function of mitochondria in the cell are disrupted, less energy is produced and organ dysfunction results.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 170
Correct
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A 43-year old male is taken to the Emergency Room for a lacerated wound on the abdomen, situated above the umbilicus. A short segment of the small bowel has herniated through the wound.Which of these anatomic structures is the deepest structure injured in the case above?
Your Answer: Transversalis fascia
Explanation:The following structures are the layers of the anterior abdominal wall from the most superficial to the deepest layer:SkinFatty layer of the superficial fascia (Camper’s fascia)Membranous layer of the superficial fascia (Scarpa’s fascia)Aponeurosis of the external and internal oblique musclesRectus abdominis muscleAponeurosis of the internal oblique and transversus abdominisFascia transversalisExtraperitoneal fatParietal peritoneum
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This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 171
Incorrect
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Regarding ciprofloxacin, which of the following statements is INCORRECT:
Your Answer: Ciprofloxacin interferes with bacterial nucleic acid synthesis.
Correct Answer: Ciprofloxacin decreases plasma concentrations of theophylline.
Explanation:Ciprofloxacin increases plasma concentrations of theophylline. There is an increased risk of convulsions when quinolones are given with NSAIDs or theophylline. There is an increased risk of tendon damage when quinolones are given with corticosteroids. Quinolones are known to increase the QT-interval and should not be taken with concomitantly with other drugs that are known to cause QT-interval prolongation. There is an increased risk of myopathy when erythromycin or clarithromycin are taken with simvastatin or atorvastatin.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 172
Correct
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A 18 year old with known asthma presents himself to ED with acute breathlessness and wheeze for the past 20 minutes. On examination he is tachypneic and tachycardic. His oxygen saturations are 96% on air. What is the first line treatment for acute asthma:
Your Answer: Salbutamol
Explanation:High-dose inhaled short-acting beta2-agonists are the first line treatment for acute asthma(salbutamol or terbutaline). Oxygen should only been given to hypoxaemic patients (to maintain oxygen saturations of 94 – 98%). A pressurised metered dose inhaler with spacer device is preferred in patients with moderate to severe asthma (4 puffs initially, followed by 2 puffs every 2 minutes according to response, up to 10 puffs, whole process repeated every 10 – 20 minutes if necessary). The oxygen-driven nebuliser route is recommended for patients with life-threatening features or poorly responsive severe asthma (salbutamol 5 mg at 15 – 30 minute intervals). Continuous nebulisation should be considered in patients with severe acute asthma that is poorly responsive to initial bolus dose (salbutamol at 5 – 10 mg/hour) The intravenous route should be reserved for those in whom inhaled therapy cannot be used reliably.
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 173
Correct
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All of the following are actions of insulin except:
Your Answer: Increased gluconeogenesis
Explanation:Major Actions of Insulin:↑ Glucose uptake into cells↑ Glycogenesis↓ Glycogenolysis↓ Gluconeogenesis↑ Protein synthesis↓ Protein degradation↑ Fat deposition↓ Lipolysis↓ Ketoacid production↑ K+ uptake into cellsMajor Actions of Glucagon:↓ Glycogenesis↑ Glycogenolysis↑ Gluconeogenesis↓ Fatty acid synthesis↑ Lipolysis↑ Ketoacid production
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 174
Incorrect
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Regarding thalassaemia, which of the following statements is CORRECT:
Your Answer: Beta-thalassaemias are usually caused by deletion of a beta globin gene.
Correct Answer: Screening for thalassaemia in pregnancy is offered to all pregnant women.
Explanation:Beta thalassemia is caused by mutations in one or both of the beta globin genes. Alpha thalassemia is caused by a deletion or mutation (less commonly) in one or more of the four alpha globin gene copies. β-thalassaemia is more common in the Mediterranean region while α-thalassaemia is more common in the Far East.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 175
Correct
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Which of these organisms is commonly spread by droplet transmission?
Your Answer: Neisseria meningitidis
Explanation:Droplets are airborne particles greater than 5 µm in size. Droplet transmission occurs during talking, coughing and sneezing where respiratory droplets are generated.Examples of organisms transmitted by the droplet route include:Neisseria meningitidisRespiratory syncytial virusParainfluenza virusBordetella pertussisInfluenza virusPoliovirus and Rotavirus are transmitted by the faeco-oral routeHepatitis B is transmitted by Sexual routeStaphylococcus aureus is transmitted by direct contact
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 176
Incorrect
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Regarding protein digestion, which of the following statements is CORRECT:
Your Answer: The pancreatic proteases, trypsin and chymotrypsin, hydrolyse polypeptides to small peptides and amino acids.
Correct Answer: Oligopeptides are broken down into small peptides and amino acids by pancreatic carboxypeptidases and aminopeptidases located on the brush border.
Explanation:Digestion of dietary protein begins in the stomach where pepsin hydrolyses protein to polypeptides, and continues in the duodenum where pancreatic proteases (trypsin and chymotrypsin) continue the process of hydrolysis forming oligopeptides. These are further broken down into small peptides and amino acids by pancreatic carboxypeptidases and aminopeptidases located on luminal membrane epithelial cells. Free amino acids are absorbed across the apical membrane by secondary active transport coupled with Na+transport into the cell. Amino acids cross the basal membrane into the capillaries by facilitated diffusion.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 177
Incorrect
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Regarding water and electrolyte absorption in the small intestine, which of the following statements is INCORRECT:
Your Answer: Na+/K+ ATPase located on the basolateral membrane of the epithelial cells pumps three Na+ ions from the cell in exchange for two K+ ions in.
Correct Answer: Na+ enters the cell across the apical membrane against its concentration gradient by both membrane channels and transporter protein mechanisms.
Explanation:As the contents of the intestine are isotonic with body fluids and mostly have the same concentration of the major electrolytes, their absorption is active. Water cannot be moved directly, but follows osmotic gradients set up by the transport of ions, primarily mediated by the sodium pump.Na+/K+ ATPase located on the basolateral membrane of the epithelial cells pumps three Na+ ions from the cell in exchange for two K+ ions, against their respective concentration gradients. This leads to a low intracellular concentration of Na+ and a high intracellular concentration of K+. The low intracellular concentration of Na+ ensures a movement of Na+ from the intestinal contents into the cell down its concentration gradient by both membrane channels and transporter protein mechanisms. Na+ is then rapidly pumped again by the basolateral sodium pump. K+ leaves the cell across the basolateral membrane down its concentration gradient linked to an outward movement of Cl- against its concentration gradient (Cl- having entered the cell across the luminal membrane down its concentration gradient).
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 178
Correct
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A patient with a high potassium level is at risk of going into cardiac arrest. What changes in the ECG may indicate the incident of cardiac arrest in this patient?
Your Answer: Peaked T waves and broad QRS complex
Explanation:Severe hyperkalaemia can result in a heart attack or a life-threatening arrhythmia. T waves become narrow-based, pointed, and tall if hyperkalaemia is not treated. The QRS complex widens and eventually merges with the T wave, resulting in a classic sine-wave electrocardiogram. Ventricular fibrillation and asystole are likely to follow.
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This question is part of the following fields:
- Physiology
- Renal
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Question 179
Correct
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Regarding the lung roots, which of the following statements is CORRECT:
Your Answer: Generally the pulmonary arteries lie superior to the pulmonary veins in the lung root.
Explanation:Each lung root contains a pulmonary artery, two pulmonary veins, a main bronchus, bronchial vessels, nerves and lymphatics. Generally the pulmonary artery is superior in the lung root, the pulmonary veins are inferior and the bronchi are somewhat posterior in position. The vagus nerves pass posterior to the lung roots while the phrenic nerves pass anterior to them.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 180
Correct
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Regarding the resting membrane potential, which of the following statements is CORRECT:
Your Answer: The resting cell membrane is more permeable to K + ions than to Na + ions.
Explanation:A membrane potential is a property of all cell membranes, but the ability to generate an action potential is only a property of excitable tissues. The resting membrane is more permeable to K+and Cl-than to other ions (and relatively impermeable to Na+); therefore the resting membrane potential is primarily determined by the K+equilibrium potential. At rest the inside of the cell is negative relative to the outside. In most neurones the resting potential has a value of approximately -70 mV.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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