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Question 1
Correct
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Glomerular filtration rate can be calculated using any substance that:
Your Answer: is freely filtered and neither reabsorbed nor secreted by the nephron
Explanation:Clearance of a substance can provide an accurate estimate of the glomerular filtration rate (GFR) provided that the substance is:freely filterednot reabsorbed in the nephronnot secreted in the nephronnot synthesised or metabolised by the kidney
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This question is part of the following fields:
- Physiology
- Renal
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Question 2
Correct
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You've been summoned to a young man in the resus area who has an SVT. You decide to use adenosine after trying several vagal manoeuvres without success.
The use of adenosine is not contraindicated in which of the following situations?Your Answer: Concurrent use of a beta-blocker
Explanation:The use of a beta-blocker at the same time increases the risk of myocardial depression, but it is not a contraindication.
The use of adenosine is contraindicated in the following situations:
Asthma
COPD (chronic obstructive pulmonary disease)
Decompensated heart failure
Long QT syndrome
AV block in the second or third degree
Sinusitis is a condition in which the sinuses become (unless pacemaker fitted)
Hypotension that is severe -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 3
Correct
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A patient presents with a history of excessive thirst, urination and high fluid intake. His blood sugar is normal. You estimate his osmolarity as part of his work-up.
Which of these equations can be used to estimate osmolarity?
Your Answer: 2 (Na + ) + 2 (K + ) + Glucose + Urea
Explanation:Osmolality and osmolarity are measurements of the solute concentration of a solution. Although the two terms are often used interchangeably, there are differences in the definitions, how they are calculated and the units of measurement used.
Osmolarity, expressed as mmol/L, is an estimation of the osmolar concentration of plasma. It is proportional to the number of particles per litre of solution.
Measured Na+, K+, urea and glucose concentrations are used to calculate the value indirectly.
It is unreliable in pseudohyponatremia and hyperproteinaemia.The equations used to calculate osmolarity are:
Osmolarity = 2 (Na+) + 2 (K+) + Glucose + Urea (all in mmol/L)
OR
Osmolarity = 2 (Na+) + Glucose + Urea (all in mmol/L)Doubling of sodium accounts for the negative ions associated with sodium, and the exclusion of potassium approximately allows for the incomplete dissociation of sodium chloride.
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 4
Correct
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A 39-year-old man with a long history of depression presents after intentionally overdoing his heart medication. Verapamil immediate-release 240 mg is the tablet he takes for this condition, he says. He took the pills about 30 minutes ago, but his wife discovered him right away and rushed him to the emergency room.
At the moment, he is completely symptom-free. When it comes to this type of overdose, how long does it usually take for symptoms to appear?Your Answer: 1-2 hours
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.
>10 tablets of verapamil (160 mg or 240 mg immediate or sustained-release capsules) or diltiazem can cause serious toxicity (180 mg, 240 mg or 360 mg immediate or sustained-release capsules)
In children, 1-2 tablets of verapamil or diltiazem (immediate or sustained-release)
Symptoms usually appear within 1-2 hours of ingestion with standard preparations. However, with slow-release preparations, significant toxicity may take 12-16 hours to manifest, with peak effects occurring after 24 hours.
The following are the main clinical features of calcium-channel blocker overdose:
Nausea and vomiting
Hypotension
Bradycardia and first-degree heart block
Myocardial ischaemia and stroke
Renal failure
Pulmonary oedema
HyperglycaemiaThe following are some of the most important bedside investigations to conduct:
Blood glucose
ECG
Arterial blood gas
Other investigations that can be helpful include
Urea & electrolytes
Chest X-ray (pulmonary oedema)
Echocardiography -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 5
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 anterior interosseous 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 6
Correct
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Red cell protein expression is induced by which of the following pathogens:
Your Answer: Plasmodium falciparum
Explanation:Plasmodium falciparum induces the expression of red cell protein, making cerebral malaria more severe. Bacteria may invade a host passively through micro traumata or macro traumata in the skin or mucosa. On the other hand, bacteria that invade
through intact mucosa first, adhere to this anatomical barrier, then actively
breach it. -
This question is part of the following fields:
- Microbiology
- Principles
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Question 7
Correct
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Which of the following nerves is most likely associated with an anterior shoulder dislocation?
Your Answer: Axillary nerve
Explanation:In an anterior dislocation, the arm is an abducted and externally rotated position. In the externally rotated position, the posterosuperior aspect of the humeral head abuts and drives through the anteroinferior aspect of the glenoid rim. This can damage the humeral head, glenoid labrum, or both. An associated humeral head compression fracture is described as a Hill Sach’s lesion. If large enough, it can lead to locked dislocations that may require open reduction. The glenoid labrum is a fibrocartilaginous structure that rings the circumference of the glenoid fossa. Bankart lesions are injuries to the anteroinferior glenoid labrum complex and the most common capsulolabral injury. A bony Bankart lesion refers to an associated fracture of the glenoid rim. These capsulolabral lesions are risk factors for recurrent dislocation.
Axillary nerve injury is identified in about 42% of acute anterior shoulder dislocations. Nerve transection is rare, and traction injuries are more common. Arterial injury has also been described. The subclavian artery becomes the axillary artery after passing the first rib. The distal portion of the axillary artery is anatomically fixed and, therefore, susceptible to injury in anterior dislocations. Ischemic injury, including pseudoaneurysm and arterial laceration, is rare but carries marked morbidity if not quickly identified.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 8
Correct
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Question 9
Incorrect
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Which of the following globin chains makes up haemoglobin A2 (HbA2)?
Your Answer: Two beta and two delta chains
Correct Answer: Two alpha chains and two delta chains
Explanation:Haemoglobin is a 64.4 kd tetramer consisting of two pairs of globin polypeptide chains: one pair of alpha-like chains, and one pair of non-alpha chains. The chains are designated by Greek letters, which are used to describe the particular haemoglobin (e.g., Hb A is alpha2/beta2).
Two copies of the alpha-globin gene (HBA2, HBA1) are located on chromosome 16 along with the embryonic zeta genes (HBZ). There is no substitute for alpha globin in the formation of any of the normal haemoglobins (Hb) following birth (e.g., Hb A, Hb A2, and Hb F). Thus, absence any alpha globin, as seen when all 4 alpha-globin genes are inactive or deleted is incompatible with extrauterine life, except when extraordinary measures are taken.
A homotetramer of only alpha-globin chains is not thought to occur, but in the absence of alpha chains, beta and gamma homotetramers (HbH and Bart’s haemoglobin, respectively) can be found, although they lack cooperativity and function poorly in oxygen transport. The single beta-globin gene (HBB) resides on chromosome 11, within a gene cluster consisting of an embryonic beta-like gene, the epsilon gene (HBE1), the duplicated and nearly identical fetal, or gamma globin genes (HBG2, HBG1), and the poorly expressed delta-globin gene (HBD). A heme group, consisting of a single molecule of protoporphyrin IX co-ordinately bound to a single ferrous (Fe2+) ion, is linked covalently at a specific site to each globin chain. If the iron is oxidized to the ferric state (Fe3+), the protein is called methaemoglobin.
Alpha globin chains contain 141 amino acids (residues) while the beta-like chains contain 146 amino acids. Approximately 75 percent of haemoglobin is in the form of an alpha helix. The non helical stretches permit folding of the polypeptide upon itself. Individual residues can be assigned to one of eight helices (A-H) or to adjacent non helical stretches.
Heme iron is linked covalently to a histidine at the eighth residue of the F helix (His F8), at residue 87 of the alpha chain and residue 92 of the beta chain. Residues that have charged side groups, such as lysine, arginine, and glutamic acid, lie on the surface of the molecule in contact with the surrounding water solvent. Exposure of the hydrophilic (charged) amino acids to the aqueous milieu is an important determinant of the solubility of haemoglobin within the red blood cell and of the prevention of precipitation.
The haemoglobin tetramer is a globular molecule (5.0 x 5.4 x 6.4 nm) with a single axis of symmetry. The polypeptide chains are folded such that the four heme groups lie in clefts on the surface of the molecule equidistant from one another.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 10
Incorrect
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Which of the following is NOT a function of bile:
Your Answer: Route of excretion of bilirubin
Correct Answer: Digestion of fats into monoglycerides and fatty acids.
Explanation:Bile functions to eliminate endogenous and exogenous substances from the liver (including bilirubin), to neutralise gastric acid in the small intestine, and to emulsify fats in the small intestine and facilitate their digestion and absorption. Bile salts also act as bactericides, destroying many of the microbes that may be present in the food. Bile doesn’t contain digestive enzymes for digestion of lipids into monoglycerides and fatty acids; this is performed mainly by pancreatic lipase.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 11
Correct
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A 73-year-old woman arrives at the emergency department 48 hours after being discharged from the hospital after a two-week stay for sepsis treatment. She has fever, productive cough with thick green sputum, and shortness of breath. An X-ray shows left lower lobe pneumonia. Which of the bacteria listed below is more likely to be the causative agent:
Your Answer: Pseudomonas aeruginosa
Explanation:Hospital-acquired pneumonia (HAP), or nosocomial pneumonia, is a lower respiratory infection that was not incubating at the time of hospital admission and that presents clinically 2 or more days after hospitalization. Pneumonia that presents sooner should be regarded as community acquired pneumonia. VAP refers to nosocomial pneumonia that develops among patients on ventilators. Ventilator-associated pneumonia (VAP) is defined as pneumonia that presents more than 48 hours after endotracheal intubation.
Common bacteria involved in hospital-acquired pneumonia (HAP) include the following [10] :
Pseudomonas Aeruginosa
Staphylococcus aureus, including methicillin-susceptible S aureus (MSSA) and methicillin-resistant S aureus (MRSA)
Klebsiella pneumoniae
Escherichia coli -
This question is part of the following fields:
- Infections
- Microbiology
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Question 12
Incorrect
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All these structures make up the portal triad EXCEPT?
Your Answer: Bile ducts
Correct Answer: Branches of the hepatic vein
Explanation:The portal triad, is made up of a portal arteriole (a branch of the hepatic artery), a portal venule (a branch of the hepatic portal vein) and a bile duct. Also contained within the portal triad are lymphatic vessels and vagal parasympathetic nerve fibres.
Branches of the hepatic vein is not part of the portal triad
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 13
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– Phenytoin
C– Carbamazepine
B– Barbiturates
R– Rifampicin
A– Alcohol (chronic ingestion)
S– Sulphonylureas
S– Smoking -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 14
Correct
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A patient with rash is examined. He has some redness of the skin that blanches when finger pressure is applied.
What is the best description of this rash that you have found on examination?Your Answer: Erythema
Explanation:Erythema is redness of the skin or mucous membranes caused by hyperaemia of superficial capillaries caused by skin injury, infection or inflammation. Erythema blanches when pressure is applied whereas ecchymosis, purpura and petechiae do not.
Ecchymosis are discolouration of the skin or mucous membranes caused by extravasation of blood. They are usually red or purple in colour and measure greater than 1 cm in diameter and do not blanch on applying pressure.
A macule is a flat, well circumscribed area of discoloured skin less than 1 cm in diameter with no changes in the thickness or texture of the skin.
Petechiae are discolouration of the skin measuring less than 3 mm in diameter
Purpura are discolouration of the skin measuring between 0.3 cm and 1 cm in diameter.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 15
Correct
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When inserting a Seldinger chest drain for management of pneumothorax, the 'safe triangle' should be identified. Which of the following forms the inferior border of the 'safe triangle'?
Your Answer: 5 th intercostal space
Explanation:Care and management of the thoracostomy tubes (chest tubes) are subject to the direction and practice pattern of the responsible physician. Therefore, it is difficult to make a “one size fits all” set of instructions about the specific management recommendations for all chest tubes. It is recommended to discuss specific expectations for management with the patient’s attending physician. Facility specific Clinical Practice Guidelines (CPGs) may provide further guidance for one’s practice.
Placement of the appropriately sized chest tube is performed on the affected side. The typical landmark for placement is the 4th or 5th intercostal space (nipple line for males, inframammary fold for females) at the anterior axillary line. The space above the 5th intercostal space and below the base of the axilla that is bordered posteriorly by the trapezius and anteriorly by the pectoralis muscle has recently been described as the safe triangle. Tubes are positioned anteriorly for pneumothoraces and posteriorly for fluid processes.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 16
Correct
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Nifedipine commonly causes which of the following adverse effects?
Your Answer: Ankle oedema
Explanation:Most common adverse effects of Nifedipine include:
Peripheral oedema (10-30%)
Dizziness (23-27%)
Flushing (23-27%)
Headache (10-23%)
Heartburn (11%)
Nausea (11%) -
This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 17
Incorrect
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Regarding chronic idiopathic thrombocytopaenic purpura (ITP), which of the following statements is INCORRECT:
Your Answer: The antibody in ITP is often directed against the glycoprotein IIb/IIIa or Ib complex.
Correct Answer: ITP is classically associated with massive splenomegaly.
Explanation:Chronic ITP is a relatively common disorder. The highest incidence is in women aged 15 – 50 years. It is the most common cause of thrombocytopaenia without anaemia or neutropaenia. It is usually idiopathic but it may been seen in association with other conditions. Platelet autoantibodies (usually IgG) result in the premature removal of platelets from the circulation by macrophages of the reticuloendothelial system. In many causes the antibody is directed against the glycoprotein IIb/IIIa or Ib complex. The normal platelet lifespan of 10 days is reduced to a few hours. Total megakaryocyte mass and platelet turnover are increased to approximately five times normal. Despite the destruction of platelets by splenic macrophages, the spleen is normally not enlarged. In fact, an enlarged spleen should lead to a search for other possible causes for the thrombocytopenia.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 18
Incorrect
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Carbamazepine is contraindicated in which of the following:
Your Answer: Hepatic impairment
Correct 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) -
This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 19
Correct
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A 50-year-old woman with painful joints had some blood tests done with her GP. The test showed she had anti-double stranded DNA antibodies.
Which one of these disorders is most likely to be associated with anti-double stranded DNA antibodies?Your Answer: Systemic lupus erythematosus (SLE)
Explanation:CREST syndrome is usually associated with anti-centromere antibodies.
Primary biliary cirrhosis is associated with anti-mitochondrial antibodies.
Sjogren’s syndrome is associated with anti-Ro and anti-La antibodies.
Polymyositis is associated with anti-Jo1 antibodies.
Anti-double stranded DNA antibodies are highly characteristic of systemic lupus erythematosus (SLE). They are a group of anti-nuclear antibodies (ANA) that target double stranded DNA and are implicated in the pathogenesis of lupus nephritis.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 20
Correct
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Regarding ACE inhibitors, which of the following statements is CORRECT:
Your Answer: Angiotensin-II receptor blockers are a useful alternative in patients who cannot tolerate ACE-inhibitors due a persistent cough.
Explanation:ACE inhibitors should be used with caution in patients of Afro-Caribbean descent who may respond less well; calcium channel blockers are first line for hypertension in these patients. ACE inhibitors have a role in the management of diabetic nephropathy. ACE inhibitors are contraindicated in pregnant women. ACE inhibitors inhibit the breakdown of bradykinin; this is the cause of the persistent dry cough. Blocking ACE also diminishes the breakdown of the potent vasodilator bradykinin which is the cause of the persistent dry cough. Angiotensin-II receptor blockers do not have this effect, therefore they are useful alternative for patients who have to discontinue an ACE inhibitor because of persistent cough.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 21
Correct
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Intrinsic factor is vital for gastrointestinal absorption of which of the following:
Your Answer: Vitamin B12
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 22
Incorrect
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Which of the following is most likely to cause a homonymous hemianopia:
Your Answer: Optic glioma
Correct Answer: Posterior cerebral artery stroke
Explanation:A posterior cerebral stroke will most likely result in a contralateral homonymous hemianopia with macular sparing.
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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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Regarding bronchiolitis, which of the following statements is CORRECT:
Your Answer: It most commonly affects children aged 3 - 4 years.
Correct Answer: Chest x-ray may show hyperinflation and increased peribronchial markings.
Explanation:Acute bronchiolitis is caused most commonly by respiratory syncytial virus, occurring mostly in children aged 6 months to 2 years. Children with bronchiolitis are febrile and tachypnoeic with a dry cough and difficulty feeding. Examination may reveal chest hyperinflation, respiratory distress, wheezing and fine end-inspiratory crepitations. Chest x-ray may show hyperinflation and increased peribronchial markings (although CXR should only performed if there is diagnostic uncertainty or an atypical course). Treatment is usually supportive, aerosolized ribavirin is reserved for severely ill or immunocompromised patients.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 24
Correct
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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: 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 25
Incorrect
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A 62-year-old woman is brought to the Emergency Department as she is acutely unwell. Her attendants inform you that she was recently started on lithium as a mood stabilizer.
You instantly send a blood sample to check for lithium levels.
What is the usual therapeutic range for lithium?Your Answer: 1.0-2.0 mmol/l
Correct Answer: 0.4-0.8 mmol/l
Explanation:Lithium is the drug of choice for recurrent bipolar illness but should be carefully monitored as it has a very low therapeutic index. The normal therapeutic range is 0.4-0.8 mmol/l.
The lower end of the range is usually the target for the elderly and as maintenance therapy. Toxicity is usually seen at levels >1.5 mmol/l. Samples should be taken 12 hours after the dose, and levels should be checked one week after starting therapy and one week after every change in dosage.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 26
Incorrect
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Which of the following is NOT a typical complication associated with mumps:
Your Answer: Meningitis
Correct Answer: Subacute sclerosing panencephalitis
Explanation:Complications of mumps include meningitis, post meningitis deafness, encephalitis, pancreatitis, orchitis and oophoritis. Subacute sclerosing panencephalitis is a complication typically associated with measles infection.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 27
Incorrect
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What is the earliest physiological effect that causes postural hypotension:
Your Answer: A fall in cardiac output
Correct Answer: A fall in central venous pressure
Explanation:When autonomic reflexes are impaired or intravascular volume is markedly depleted, a significant reduction in blood pressure occurs upon standing, a phenomenon termed Postural Hypotension (orthostatic hypotension). Orthostatic hypotension can cause dizziness, syncope, and even angina or stroke. When autonomic reflexes are impaired, blood pressure falls progressively after standing because the gravitational pooling of blood in the legs cannot be compensated by sympathetic vasoconstriction.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 28
Correct
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Which of the following is a clinical effect of hyperkalaemia:
Your Answer: Muscle weakness
Explanation:Clinical features of hyperkalaemia may include:
paraesthesia, muscle weakness or paralysis, cardiac conduction abnormalities and dysrhythmias.Clinical features of hypokalaemia may include:
muscle weakness, muscle cramps, rhabdomyolysis and myoglobinuria, ascending paralysis resulting in respiratory failure, constipation, gut ileus with distension, anorexia, nausea and vomiting, impaired ADH action with polyuria and polydipsia, ECG changes and cardiac arrhythmias. -
This question is part of the following fields:
- Physiology
- Renal
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Question 29
Incorrect
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A 22-year-old woman comes in with an asthmatic flare. Salbutamol is her only regular medication.
What is the dosage per inhalation of a standard metered dose salbutamol inhaler?Your Answer: 200 micrograms
Correct Answer: 100 micrograms
Explanation:The dose of a conventional metered dose inhaler is 100 micrograms per metered inhalation.
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This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 30
Correct
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During swallowing, which of the following structures primarily closes the tracheal opening:
Your Answer: Epiglottis
Explanation:The vocal cords of the larynx are strongly
approximated, and the larynx is pulled upward
and anteriorly by the neck muscles. These actions,
combined with the presence of ligaments that
prevent upward movement of the epiglottis, cause
the epiglottis to swing back over the opening
of the larynx. All these effects acting together
prevent the passage of food into the nose and
trachea. Most essential is the tight approximation
of the vocal cords, but the epiglottis helps to
prevent food from ever getting as far as the vocal
cords. Destruction of the vocal cords or of the
muscles that approximate them can cause
strangulation. -
This question is part of the following fields:
- Gastrointestinal
- Physiology
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SESSION STATS - PERFORMANCE PER SPECIALTY
