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Question 1
Correct
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You're evaluating a male patient who's having a lung function test done. In calculating the patient’s functional residual capacity, what parameters should you add to derive the functional residual capacity volume?
Your Answer: Expiratory reserve volume + residual volume
Explanation:The volume of air that remains in the lungs after a single breath is known as functional residual capacity (FRC). It is calculated by combining the expiratory reserve volume and residual volume.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 2
Incorrect
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A 17-year-old male patient diagnosed with cystic fibrosis is experiencing shortness of breath, coughing, and flu-like symptoms. His X-ray results shows atelectasis, or collapsed lung, specifically in his lower right lung. All of the following statements are true regarding collapsed lungs, except for which one.
Your Answer: The alveoli remain perfused in atelectasis
Correct Answer: Atelectasis is an example of a perfusion defect
Explanation:Atelectasis is a complete or partial collapse of the lung. It occurs when the alveoli deflate or are filled with alveolar fluid. It is considered a ventilation defect of the alveoli due to cystic fibrosis. It is not a perfusion defect. A perfusion defect will produce pathological dead space in which the lung alveoli are ventilated adequately but are not perfused, and there is no gas exchange. While with atelectasis, the alveoli remain perfused. However, there is impaired oxygen delivery and intrapulmonary shunting of blood will be present in the collapsed area. Since there is no exchange of gas at the capillary-alveolar interface of the collapsed segments, the pulmonary capillary blood will have similar PO2 and PCO2.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 3
Correct
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One of your patients is in resuscitation and is suffering from kidney failure. The intensive care outreach team arrives to assess them and determines that a dopamine infusion is necessary.Dopamine primarily acts on which of the following receptors at low doses?
Your Answer: Dopamine receptors
Explanation:Dopamine is a catecholamine that occurs naturally and is used to treat low cardiac output, septic shock, and renal failure. It is both adrenaline and noradrenaline’s immediate precursor.Dopamine acts on D1 and D2 dopamine receptors in the renal, mesenteric, and coronary beds at low doses (1-5 g/kg/min). Dopamine causes a significant decrease in renal vascular resistance and an increase in renal blood flow at these doses. Within this dose range, it is also involved in central modulation of behaviour and movement.Dopamine stimulates beta- and alpha-adrenergic receptors directly and indirectly at higher doses. Beta-stimulation predominates at a rate of 5-10 g/kg/min, resulting in a positive inotropic effect that increases cardiac output and coronary blood flow. Alpha-stimulation predominates at infusion rates greater than 15 g/kg/min, resulting in peripheral vasoconstriction and an increase in venous return and systolic blood pressure.Below is a summary of the mechanisms and effects of various inotropic agents:InotropeMechanismEffectsAdrenaline (epinephrine)Beta-1 and -2 agonist at increasing doses;Alpha-agonist at high dosesIncreased cardiac output;Vasoconstriction at higher dosesNoradrenaline (norepinephrine)Mainly alpha-agonist;Beta-1 and -2 agonist at increasing dosesVasoconstriction;Some increased cardiac outputDopamineDopamine agonist at low doses;Beta-1 and -2 agonist at increasing doses;Alpha-agonist at high dosesIncreased cardiac output;Vasoconstriction at higher dosesDobutamineMainly beta-1 agonistIncreased cardiac output
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 4
Incorrect
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A migrant from Eastern Europe needs to have screening performed for tuberculosis (TB) because he is a high-risk patient.Which statement concerning TB screening in the UK is true?
Your Answer: The Mantoux test involves the injection via a multi-pronged gun of 100,000 units/ml of tuberculin purified protein derivative into the skin
Correct Answer: Vaccination with the BCG can result in a false positive test
Explanation:Vaccination with the BCG can result in a false positive test.The Mantoux test replaced the Heaf test as the TB screening test in the UK in 2005.The ‘Sterneedle’ gun is used to inject 100,000 units/ml of tuberculin purified protein derivative into the skin for the Heaf testThe Mantoux test involves the injection of 5 Tuberculin units (0.1mL) intradermally and the result read 2-3 days later. The interferon gamma release assay (IGRA) should NOT be used for neonates
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 5
Incorrect
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A patient in a high-dependency unit complains of severe and painful muscle cramps. His total corrected plasma calcium level is 1.90 mmol/L.What is the most likely underlying cause?
Your Answer: Lithium
Correct Answer: Rhabdomyolysis
Explanation:Hypocalcaemia occurs when there is abnormally low level of serum calcium ( >2.2 mmol/l) after correction for the serum albumin concentration.Rhabdomyolysis causes hyperphosphatemia, and this leads to a reduction in ionised calcium levels.Patients with rhabdomyolysis are commonly cared for in a high dependency care setting. Addison’s disease, hyperthyroidism, thiazide diuretics and lithium all cause hypercalcaemia.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 6
Incorrect
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A known epileptic is transported in status epilepticus by ambulance. On the way to the hospital, she took some diazepam.Which of the following statements about diazepam is correct?
Your Answer:
Correct Answer: It crosses into breast milk
Explanation:Diazepam boosts GABA’s effects, giving it sedative, hypnotic, anxiolytic, anticonvulsant, and muscle-relaxing properties. It can be administered orally, rectally, or intravenously.With a half-life of 20-100 hours, it is a long-acting benzodiazepine. Midazolam, oxazepam, and alprazolam are examples of short-acting benzodiazepines with a half-life of less than 12 hours (Xanax).If used in the presence of hepatic impairment, benzodiazepines can cause coma. If treatment is necessary, benzodiazepines with shorter half-lives should be used in lower doses. Diazepam is a sedative that crosses into breast milk and should be avoided by breastfeeding mothers.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 7
Incorrect
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Regarding Clostridium species, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: They are facultative anaerobes.
Explanation:Clostridium spp. are obligatory anaerobic spore-forming Gram-positive bacilli. Toxin production is the main pathogenicity mechanism.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 8
Incorrect
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Bendoflumethiazide may cause all of the following electrolyte imbalances EXCEPT for:
Your Answer:
Correct Answer: Hypocalcaemia
Explanation:Common side effects of thiazide diuretics include:Excessive diuresis, postural hypotension, dehydration, renal impairmentAcid-base and electrolyte imbalanceHypokalaemia, hyponatraemia, hypomagnesaemia, hypercalcaemia, hypochloraemic alkalosisMetabolic imbalanceHyperuricaemia and goutImpaired glucose tolerance and hyperglycaemiaAltered plasma-lipid concentrationsMild gastrointestinal disturbances
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 9
Incorrect
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Which of the following organelles form lysosomes?
Your Answer:
Correct Answer: The Golgi apparatus
Explanation:Lysosomes are formed by the Golgi apparatus or the endoplasmic reticulum. Lysosome releases its enzymes and digests the cell when the cell dies.
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 10
Incorrect
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A 18-year-old man returns from a trip to Ibiza with a severely painful left eye. He has copious mucopurulent discharge, is febrile and has left-sided tender preauricular lymphadenopathy. He attends the local eye casualty and is diagnosed with hyperacute conjunctivitis.What is the SINGLE most likely causatiave organism?
Your Answer:
Correct Answer: Neisseria gonorrhoeae
Explanation:Hyperacute bacterial conjunctivitis is a severe, sight-threatening ocular infection that warrants immediate ophthalmic work-up and management. The infection has an abrupt onset and is characterized by a copious yellow-green purulent discharge that reaccumulates after being wiped away. Typically caused by infection with Neisseria gonorrhoeae.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 11
Incorrect
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After what time period should intravenous phenytoin be used as second-line treatment of status epilepticus?
Your Answer:
Correct Answer: 25 minutes
Explanation:If seizures recur or fail to respond after initial treatment with benzodiazepines within 25 minutes of onset, phenytoin sodium, fosphenytoin sodium, or phenobarbital sodium should be used.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 12
Incorrect
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Regarding hepatitis B, which of the following statements is CORRECT:
Your Answer:
Correct Answer: Chronic hepatitis B infection is indicated by the persistence of HBsAg for more than 6 months.
Explanation:Chronic hepatitis B infection is indicated by the persistence of HBsAg for more than 6 months. Hepatitis B has a long incubation period of about 2 – 6 months. Hepatitis B vaccine has recently been introduced to the routine childhood immunisation schedule – given at 2, 3 and 4 months. It is also given to babies born to hepatitis B infected mothers at birth, four weeks and 12 months old. Treatment of acute hepatitis is supportive. Treatment with antivirals should be considered in chronic infection as responders have a reduced risk of liver damage and liver cancer in the long term.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 13
Incorrect
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Vitamin D is a group of secosteroids that play a role in calcium and phosphate control. Vitamin D's hormonally active metabolite is 1,25-dihydroxycholecalciferol.Which enzyme hydroxylates 25-hydroxycholecalciferol to form 1,25-dihydroxycholecalciferol?Â
Your Answer:
Correct Answer: 1-alpha-hydroxylase
Explanation:The hormone-active metabolite of vitamin D is 1,25-dihydroxycholecalciferol (commonly known as calcitriol). Its activities raise calcium and phosphate levels in the bloodstream.In the presence of UVB light, 7-dehydrocholesterol is converted to cholecalciferol in the epidermal layer of the skin, resulting in 1,25-dihydroxycholecalciferol.Cholecalciferol is then converted to 25-hydroxycholecalciferol in the endoplasmic reticulum of liver hepatocytes by 25-hydroxylase (calcifediol).Finally, 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 induced by parathyroid hormone or hypophosphatemia.The following are the primary effects of 1,25-dihydroxycholecalciferol:Calcium and phosphate absorption in the small intestine is increased.Calcium reabsorption in the kidneys is increased.Increases phosphate reabsorption in the kidneys.Increases the action of osteoclastic bacteria (increasing calcium and phosphate resorption from bone)Inhibits the action of 1-alpha-hydroxylase in the kidneys (negative feedback)
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 14
Incorrect
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Among the following infectious diseases, which is typically considered to have an incubation period of 3 weeks and longer?
Your Answer:
Correct Answer: Infectious mononucleosis
Explanation:Infectious mononucleosis is caused by Epstein-Barr virus (EBV). The incubation period for EBV varies from 2 weeks to 2 months.The usual incubation period for rubella is 14 days; with a range of 12 to 23 days.Gonorrhoea has a short incubation period of approximately 2 to 7 days.The mumps virus can be isolated from infected saliva and swabs rubbed over the Stensen’s duct from 9 days before onset of symptoms until 8 days after parotitis appears.Scarlet fever, which appears within 1 to 2 days after bacterial infection, is characterized by a diffuse red rash that appears on the upper chest and spreads to the trunk and extremities. The rash disappears over the next 5 to7 days and is followed by desquamation.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 15
Incorrect
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Which of the following statements accurately describes the flexor digitorum superficialis muscle?
Your Answer:
Correct Answer: It flexes the middle phalanges of the medial four fingers at the proximal interphalangeal joints
Explanation:Flexor digitorum superficialis is the largest muscle of the anterior compartment of the forearm. It belongs to the superficial flexors of the forearm, together with pronator teres, flexor carpi radialis, flexor carpi ulnaris and palmaris longus. Some sources alternatively classify this muscle as an independent middle/intermediate layer of the anterior forearm, found between the superficial and deep groups.Flexor digitorum superficialis is innervated by muscular branches of the median nerve, derived from roots C8 and T1 that arises from the medial and lateral cords of the brachial plexus. The skin that overlies the muscle is supplied by roots C6-8 and T1.The primary arterial blood supply to the flexor digitorum superficialis is derived from the ulnar artery and its anterior recurrent branch. In addition to branches of the ulnar artery, the anterior and lateral surfaces of the muscle are supplied by branches of the radial artery; and its posterior surface also receives branches from the median artery.The main function of flexor digitorum superficialis is flexion of the digits 2-5 at the proximal interphalangeal and metacarpophalangeal joints. Unlike the flexor digitorum profundus, flexor digitorum superficialis has independent muscle slips for all four digits. This allows it to flex the digits individually at their proximal interphalangeal joints. In addition, flexor digitorum superficialis aids the aids flexion of the wrist.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 16
Incorrect
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Antidiuretic hormone (ADH) levels are found to be increased in a young lady with unexplained hyponatraemia.Which of the following is a result of the release of ADH?
Your Answer:
Correct Answer: Small volumes of concentrated urine
Explanation:ADH, or antidiuretic hormone, is a hormone that regulates water and electrolyte balance. It is released in response to a variety of events, the most important of which are higher plasma osmolality or lower blood pressure. ADH increases plasma volume and blood pressure via acting on the kidneys and peripheral vasculature.ADH causes extensive vasoconstriction by acting on peripheral V1 Receptors.ADH binds to B2 Receptors in the terminal distal convoluted tubule and collecting duct of the kidney, increasing transcription and aquaporin insertion in the cells that line the lumen. Aquaporins are water channels that allow water to pass through the tubule and into the interstitial fluid via osmosis, lowering urine losses.The permeability of the distal collecting duct (the section within the inner medulla) to urea is likewise increased by ADH. More urea travels out of the tubule and into the peritubular fluid, contributing to the counter current multiplier, which improves the Loop of Henle’s concentrating power.Overall, there is enhanced urea and water reabsorption in the presence of ADH, resulting in modest amounts of concentrated urine. There is minimal urea and water reabsorption in the absence of ADH, resulting in huge amounts of dilute urine.
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 17
Incorrect
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Flumazenil is a reversal agent for which of the following groups of drugs:
Your Answer:
Correct Answer: Benzodiazepines
Explanation:Flumazenil is a benzodiazepine antagonist used for the reversal of the sedative effects of benzodiazepines after anaesthesia, sedation and similar procedures.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 18
Incorrect
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Which one these is an example of a cause of an exudate?
Your Answer:
Correct 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 19
Incorrect
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Intravenous glucose solutions are typically used in the treatment of all of the following situations except:
Your Answer:
Correct Answer: Hypokalaemia
Explanation:In hypokalaemia, initial potassium replacement therapy should not involve glucose infusions, as glucose may cause a further decrease in the plasma-potassium concentration. Glucose infusions are used for the other indications like diabetic ketoacidosis, hypoglycaemia, routine fluid maintenance in patients who are nil by mouth (very important in children), and in hyperkalaemia.
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This question is part of the following fields:
- Fluids And Electrolytes
- Pharmacology
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Question 20
Incorrect
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A patient with pronounced tremor, muscle contractions, muscle spasms, and slowness of movement is brought in by his family. He has a long history of mental health issues for which he is currently treated with a variety of medications.Which of the medications listed below is most likely to be the cause of these side effects?
Your Answer:
Correct Answer: Haloperidol
Explanation:Acute dyskinesias and dystonic reactions, tardive dyskinesia (rhythmic, involuntary movements of the tongue, face, and jaw), Parkinsonism (tremor, bradykinesia, and rigidity), akinesia, akathisia, and neuroleptic malignant syndrome are all examples of extrapyramidal side effects. They are caused by dopamine depletion or blockade in the basal ganglia; this lack of dopamine frequently mimics idiopathic extrapyramidal pathologies.The first-generation antipsychotics, which are strong dopamine D2 receptor antagonists, are the drugs most commonly associated with extrapyramidal side effects. Haloperidol and fluphenazine are the two drugs in this class that are most commonly associated with extrapyramidal side effects. Extrapyramidal adverse effects are less common in second-generation antipsychotics (e.g., olanzapine) than in first-generation antipsychotics.Other drugs are linked to extrapyramidal symptoms as well, but at a lower rate. Some antidepressants, lithium, various anticonvulsants, antiemetics, and, in rare cases, oral contraceptive agents are among them.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 21
Incorrect
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Urine flow rate = 2 ml/minUrine concentration of creatinine = 18 mg/ml Plasma concentration of creatinine = 0.25 mg/ml What is the estimated glomerular filtration rate (eGFR)?
Your Answer:
Correct Answer: 144 ml/min
Explanation:GFR can be estimated by:GFR = UCr x V / PCrWhere:UCr = urine concentration of creatininePCr = plasma concentration of creatinineV = rate of urine flowIn this case GFR = (18 x 2) / 0.25 = 144 ml/minNote: Creatinine is used to estimate GFR because it is an organic base naturally produced by muscle breakdown, it is freely filtered at the glomerulus, it is not reabsorbed from the nephron, it is not produced by the kidney, it is not toxic, and it doesn’t alter GFR.
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 22
Incorrect
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A 54 year old patient presents with vertigo, ipsilateral hemiataxia, dysarthria, ptosis and miosis. Which of these blood vessels has most likely been occluded?
Your Answer:
Correct Answer: Posterior inferior cerebellar artery
Explanation:Posterior inferior cerebellar artery (PICA) occlusion is characterised by vertigo, ipsilateral hemiataxia, dysarthria, ptosis and miosis. PICA occlusion causes infarction of the posterior inferior cerebellum, inferior cerebellar vermis and lateral medulla.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 23
Incorrect
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You're currently treating an infection in a patient and trying to figure out which antibiotic would be best.Which of the following antimicrobial drugs inhibits the formation of cell walls?
Your Answer:
Correct Answer: Cefuroxime
Explanation:Cefuroxime and other cephalosporin antibiotics are bactericidal ß-lactam antibiotics. They work similarly to penicillins in that they prevent cross-linking between the linear peptidoglycan polymer chains that make up the bacterial cell wall. As a result, they prevent the formation of cell walls.The following is a summary of the various mechanisms of action of various types of antimicrobial agents:1) Inhibition of cell wall synthesisPenicillinsCephalosporinsVancomycin2) Disruption of cell membrane functionPolymyxinsNystatinAmphotericin B3) Inhibition of protein synthesisMacrolidesAminoglycosidesTetracyclinesChloramphenicol4) Inhibition of nucleic acid synthesisQuinolonesTrimethoprim5-nitroimidazolesRifampicin5) Anti-metabolic activitySulphonamidesIsoniazid
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 24
Incorrect
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A 50-year-old man has recently been on antibiotics for a chest infection. He suffers from COPD and is currently on Seretide inhalers, salbutamol, and Phyllocontin continus. Since commencing the antibiotics, he has developed nausea, vomiting and abdominal pain.Which of the following antibiotics has he MOST LIKELY been on for his chest infection?
Your Answer:
Correct Answer: Erythromycin
Explanation:Phyllocontin continues contains aminophylline, a bronchodilator used in the management of asthma and COPD.The index patient is exhibiting symptoms of theophylline toxicity. This may have been triggered by the antibiotic he took. Macrolide antibiotics, like erythromycin and quinolone antibiotics, like ciprofloxacin and levofloxacin, increases the plasma concentration of theophyllines and can lead to toxicity.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
Incorrect
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Which of the following features of cell damage tends to be reversible:
Your Answer:
Correct Answer: Swelling of endoplasmic reticulum and some mitochondria
Explanation:Features of cell damage that tend to be reversible include: swelling of endoplasmic reticulum and some mitochondrialoss of ribosomescell stress responseFeatures of cell damage that tend to be irreversible include: loss of nucleolus, no ribosomes, swelling of all mitochondria, nuclear condensation, membrane blebs and holes, lysosome rupture, fragmentation of all inner membranes, nuclear breakup
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This question is part of the following fields:
- Inflammatory Responses
- Pathology
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Question 26
Incorrect
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Which of the following statements is correct with regards to Horner's syndrome?
Your Answer:
Correct Answer: Miosis occurs due to paralysis of the dilator pupillae muscle.
Explanation:The characteristics of Horner’s syndrome are pupil constriction, partial ptosis and anhidrosis.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 27
Incorrect
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A 65-year-old man presents with cough and shortness of breath. His sputum is rusty in colour and is suffering from a fever. Upon examination, it was noted that he has crackles in the right upper lobe. A chest X-ray showed the presence of a right upper lobe cavitation.Among the following microorganisms, which is considered to be mostly associated with a cavitating upper lobe pneumonia?
Your Answer:
Correct Answer: Klebsiella pneumoniae
Explanation:Klebsiella pneumoniae is among the most common Gram-negative bacteria encountered by physicians worldwide and accounts for 0.5-5.0% of all cases of pneumonia. This organism can cause extensive pulmonary necrosis and frequent cavitation.It is one of the causes that could be suspected when there is cavitatory pneumonia with or without a bulging fissure sign. Often, there can be extensive lobar opacification with air bronchograms.A helpful feature which may help to distinguish from pneumococcal pneumonia is that Klebsiella pneumoniae develops cavitation in 30-50% of cases (in comparison, cavitation is rare in pneumococcal pneumonia). This occurs early and progresses quickly.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 28
Incorrect
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Severe vomiting and diarrhoea were reported by a 25-year-old man. He's dehydrated and needs intravenous fluids to rehydrate. You give him cyclizine as part of his treatment.What is cyclizine's main mechanism of action?
Your Answer:
Correct Answer: Antihistamine action
Explanation:Cyclizine is a piperazine derivative that functions as an antihistamine (H1-receptor antagonist). To prevent nausea and vomiting, it is thought to act on the chemoreceptor trigger zone (CTZ) and the labyrinthine apparatus. It has a lower antimuscarinic effect as well.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 29
Incorrect
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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:
Correct 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 30
Incorrect
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A 70-year-old man presents with right-sided hemiplegia and loss of joint position sense, vibratory sense, and discriminatory touch. Upon further physical examination, it was observed that her tongue deviates to the left-hand side. An MRI and CT scan was ordered and results showed that he was suffering a left-sided stroke. Branches of which of the following arteries are most likely implicated in the case?
Your Answer:
Correct Answer: Anterior spinal artery
Explanation:Medial medullary syndrome is a form of stroke that affects the medial medulla of the brain. It is caused by a lesion in the medial part of the medulla, which is due to an infraction of vertebral arteries and/or paramedian branches of the anterior spinal artery.It is characterized by contralateral paralysis of the upper and lower limb of the body, a contralateral decrease in proprioception, vibration, and/or fine touch sensation, paresthesias or less commonly dysesthesias in the contralateral trunk and lower limb, and loss of position and vibration sense with proprioceptive dysfunction. Ipsilateral deviation of the tongue due to ipsilateral hypoglossal nerve damage can also be seen.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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SESSION STATS - PERFORMANCE PER SPECIALTY
