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Question 1
Correct
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An injury to which nerve affects innervation to the adductor portion of the adductor magnus?
Your Answer: Posterior branch of the obturator nerve
Explanation:The nerves that supply the adductor magnus muscle have an embryologic origin from the anterior divisions of the lumbosacral plexus and include the obturator nerve, posterior division (L2-4), and the tibial portion of the sciatic nerve (L4). It is innervated by the posterior division of the obturator nerve.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 2
Correct
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What is the interquartile range of the following data set: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70
Your Answer: 30
Explanation:5, 10, 15 /20, 25, 30 /35, 40, 45 /50, 60, 70
Sample size (n) = 12
Median = [(n+1)/2]th value
= (12+1)/2 = 6.5
= halfway between 6th and 7th value
= (30 +35)/2 = 32.5
The lower (first) quartile =Â halfway between 15 and 20
= 17.5
The upper (third) quartile = halfway between 45 and 50
= 47.5
The interquartile range is the difference between the upper quartile and lower quartile
= 47.5 – 17.5 = 30 -
This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 3
Incorrect
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A 72-year-old woman presents to your clinic with worsening oedema. She has ischaemic heart disease and heart failure. You decide to add a loop diuretic to her current drug regime to control the oedema. Which of the following is a contraindication to using a loop diuretic?
Your Answer: Hypotension
Correct Answer: Anuria
Explanation:Loop diuretics are drugs used to manage and treat fluid overload associated with CHF, liver cirrhosis, and renal disease. The drugs commonly used are:
- Furosemide
- Bumetanide
- Torsemide
- Ethacrynic Acid
Loop diuretics inhibit the Na-K-Cl pump in the ascending loop of Henle, resulting in salt-water excretion. This relieves congestion and reduces oedema.
The contra-indications to the use of loop diuretics are:
1. Anuria
2. Comatose and precomatose states associated with liver cirrhosis
3. Renal failure due to nephrotoxic or hepatotoxic drugs
4. Severe hypokalaemia
5. Severe hyponatremia
6. History of hypersensitivity to furosemide, bumetanide, or torsemide (or sulphonamides)The following conditions or states are not contraindications, but loop diuretics needs to be used cautiously in these conditions:
1. Diabetes (but hyperglycaemia less likely than with thiazides)
2. Gout
3. Hypotension (correct before initiation of treatment)
4. Hypovolaemia (Correct before initiation of treatment) -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 4
Correct
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Regarding beta-thalassaemia, which of the following statements is CORRECT:
Your Answer: Beta-thalassaemia trait is associated with a raised HbA2.
Explanation:Beta-thalassaemia major is caused by a complete or almost complete failure of β-globin chain synthesis, severe imbalance of α:β-chains with deposition of α-chains in erythroblasts, ineffective erythropoiesis and extramedullary haemopoiesis. The severe anaemia becomes apparent at 3 – 6 months when the switch from γ-chain to β-chain synthesis normally occurs. Beta-thalassaemia minor is a variable syndrome, milder than thalassaemia major, with later onset and characterised by moderate hypochromic microcytic anaemia with raised haemoglobin A2. Beta-thalassaemia trait is characterised by mild hypochromic, microcytic anaemia with raised red cell count and raised haemoglobin A2.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 5
Correct
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A 29-year-old woman with a skin infection not responding to first-line antibiotics return for a review clinic appointment. The result of her culture shows growth of methicillin-resistant Staphylococcus aureus (MRSA).
Which among the following antibiotics is methicillin-resistant Staphylococcus aureus usually sensitive to?Your Answer: Linezolid
Explanation:Historically, MRSA has been treated successfully with outpatient oral sulphonamides, clindamycin, rifampin, doxycycline, or a combination of these agents. With the development of increasing drug resistance of MRSA to these traditional antimicrobials, there has been a search for more effective antibiotics. One recent study demonstrated that vancomycin, linezolid, and quinupristin-dalfopristin were the most effective antibiotics against multiple strains of MRSA.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 6
Correct
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In the Emergency Department, a 35-year-old woman actively seizing is brought in. She is quickly shifted into the resuscitation room and is administered a dose of benzodiazepine. The seizure is quickly terminated.
Once the patient is stable, she tells you she is a known case of epilepsy and takes phenytoin to control it.
Which of the following is the primary mechanism of action of phenytoin?Your Answer: Sodium channel blocker
Explanation:Phenytoin is in the anticonvulsants class of drugs and is used in the management and treatment of the following:
1. epilepsy
2. generalized tonic-clonic seizures
3. complex partial seizures
4. status epilepticus.It works by inactivating the voltage-gated sodium channels responsible for increasing the action potential. It is non-specific and targets almost all voltage-gated sodium channel subtypes. More specifically, phenytoin prevents seizures by inhibiting the positive feedback loop that results in neuronal propagation of high-frequency action potentials.
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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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What type of pump is the Na+/K+ATPase pump?
Your Answer: An example of facilitated diffusion
Correct Answer: An antiporter
Explanation:In order for primary active transport to pump ions against their electrochemical gradient, chemical energy is used in the form of ATP. This is facilitated by the Na+/K+-ATPase antiporter pump, which uses metabolic energy to move 3 Na+ions out of the cell for every 2 K+ions that come in, against their respective electrochemical gradients. As a result, the cell the maintains a high intracellular concentration of K+ions and a low concentration of Na+ions.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 8
Correct
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A patient presents with an acute severe asthma attack. Following a poor response to his initial salbutamol nebuliser, you administer a further nebuliser that this time also contains ipratropium bromide.
After what time period would you expect the maximum effect of the ipratropium bromide to occur? Select ONE answer only.Your Answer: 30 -60 minutes
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) -
This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 9
Correct
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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 of the following actions of 1,25-dihydroxycholecalciferol is a direct action?Your Answer: Increases renal phosphate reabsorption
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.
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)
Thyroid hormone (parathyroid hormone) Calcium reabsorption in the tubules of the kidneys is increased, but renal phosphate reabsorption is decreased. -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 10
Correct
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What is the main mechanism of action of metoclopramide:
Your Answer: Dopamine antagonist
Explanation:Metoclopramide is a dopamine-receptor antagonist. Blockade of inhibitory dopamine receptors in the GI tract may allow stimulatory actions of ACh at muscarinic synapses to predominate. Metoclopramide also blocks dopamine D2-receptors within the chemoreceptor trigger zone (CTZ). At high doses, it is also thought to have some 5-HT3antagonist activity.
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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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Your consultant decides to use ketamine for a patient requiring procedural sedation in the Emergency Department. At what receptor does ketamine primarily act:
Your Answer: NMDA receptor
Explanation:In contrast to most other anaesthetic agents, ketamine is a NMDA (N-methyl-D-aspartate) receptor antagonist. It is a non-competitive antagonist of the calcium-ion channel in the NMDA receptor. It further inhibits the NMDA-receptor by binding to its phencyclidine binding site. Ketamine also acts at other receptors as an opioid receptor agonist (analgesic effects), as an muscarinic anticholinergic receptor antagonist (antimuscarinic effects) and by blocking fast sodium channels (local anaesthetic effect).
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 12
Correct
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You're taking a history of a 59-year-old banker who has had heartburn in the past.
Which of the following information about antacids is correct?Your Answer: Magnesium carbonate can reduce the absorption of drugs taken at the same time
Explanation:Antacids such as aluminium hydroxide and magnesium carbonate are commonly used. They’re both water-insoluble and can reduce the absorption of drugs taken together. Allow at least 1-2 hours between taking these antacids and any other medications.
Because it reduces gastrointestinal phosphate absorption, aluminium hydroxide can also be used to treat hyperphosphatemia in patients with renal failure.
Magnesium carbonate has a laxative effect, whereas aluminium hydroxide has a constipating effect.
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This question is part of the following fields:
- Gastrointestinal Pharmacology
- Pharmacology
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Question 13
Correct
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You received a patient with a 2-day history of diarrhoea and vomiting. Later, after examination, the patient was found to have progressive symmetric descending flaccid paralysis, initial development of blurred vision, dysphagia, and weakness of the upper limbs. The patient is apyrexial and his observations are all normal. Which of the following pathogens is responsible for the said symptoms?
Your Answer: Clostridium botulinum
Explanation:A botulism infection results in neuroparalysis caused by the neurotoxin generated by Clostridium botulinum.
Food-borne botulism symptoms often appear 12-36 hours after ingestion of the toxin-containing food and may include nausea, vomiting, stomach discomfort, and diarrhoea at first. The most common neurological pattern is an acute onset of bilateral cranial neuropathies with symmetric declining weakening.
Other distinguishing characteristics include the absence of fever, the absence of cognitive abnormalities, the presence of a normal heart rate and blood pressure, and the absence of sensory defects.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 14
Correct
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In which of the following would you NOT typically see a neutropaenia:
Your 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)
Cyclical
Immune (e.g. SLE, Felty’s syndrome, hypersensitivity and anaphylaxis)
Leukaemia
Infections (e.g. HIV, hepatitis, fulminant bacterial infection)
General Pancytopaenia
Hypersplenism, aplastic anaemia, malignant infiltration of bone marrow, megaloblastic anaemia, chemotherapy, myelodysplasia -
This question is part of the following fields:
- Immune Responses
- Pathology
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Question 15
Correct
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A patient presents with nausea, anorexia, jaundice and right upper quadrant pain. A diagnosis of acute hepatitis B is suspected.
Which of the following blood results is most suggestive of an acute hepatitis B infection? Select ONE answer only.Your Answer: HBsAg positive, IgM anti-HBc positive
Explanation:Hepatitis B surface antigen (HBsAg) is a protein on the surface of the hepatitis B virus, that is the first serologic marker to appear in a new acute infection.It can be detected as early as 1 week and as late as 9 weeks. It can be detected in high levels in serum during acute or chronic hepatitis B virus infection. The presence of HBsAg indicates that the person is infectious. The body normally produces antibodies to HBsAg as part of the normal immune response to infection. HBsAg is the antigen used to make hepatitis B vaccine.
Hepatitis B surface antibody (anti-HBs) indicates recovery and immunity from the hepatitis B virus infection. Anti-HBs also develops in a person who has been successfully vaccinated against hepatitis B.
Total hepatitis B core antibody (anti-HBc): Appears at the onset of symptoms in acute hepatitis B and persists for life. The presence of anti-HBc indicates previous or ongoing infection with hepatitis B virus in an undefined time frame. It is not present following hepatitis B vaccination.
IgM antibody to hepatitis B core antigen (IgM anti-HBc) indicates recent infection with hepatitis B virus (<6 months). Its presence indicates acute infection.
The following table summarises the presence of hepatitis B markers according to each situation:
Susceptible to infection:
HBsAg = Negative
Anti-HBc = Negative
Anti-HBs = NegativeImmune due to natural infection:
HBsAg = Negative
Anti-HBc = Positive
Anti-HBs = PositiveImmune due to vaccination:
HBsAg = Negative
Anti-HBc = Negative
Anti-HBs = PositiveAcute infection:
HBsAg = Positive
Anti-HBc = Positive
Anti-HBs = Negative
IgM anti-HBc = PositiveChronic infection:
HBsAg = Positive
Anti-HBc = Positive
Anti-HBs = Negative
IgM anti-HBc = Negative -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 16
Correct
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Which of the following statements is correct with regards to Klebsiella spp?
Your 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 17
Correct
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A 53-year-old man arrives at the emergency department complaining of visual impairment in his right eye. On examination, you notice that neither his right nor left pupil constricts when you shine a light in his right eye. When you flash a light in his left eye, the pupils of both his left and right eyes constrict. Which of the following nerves is the most likely to be affected:
Your Answer: Optic nerve
Explanation:In full optic nerve palsy, the afferent pupillary light reflex is lost. Because the afferent optic nerve does not sense light flashed in the afflicted eye, the ipsilateral direct and contralateral consensual reflexes are gone. However, the contralateral direct and ipsilateral consensual reflexes are intact because the efferent oculomotor nerve is normal.
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This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
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Question 18
Correct
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A six-year-old boy presents with coryzal symptoms that have persisted for more than two weeks. He was born and raised in the Middle East. His mother claims he has been tired and has complained of various 'aches and pains.' On examination, you find splenomegaly and enlarged cervical lymph nodes. His legs and arms are covered in petechiae.
In this case, what is the most likely diagnosis?Your Answer: Acute lymphoblastic leukaemia (ALL)
Explanation:ALL is the most common leukaemia in children, with a peak incidence between the ages of 2 and 5.
ALL has a wide range of clinical symptoms, but many children present with an acute illness that resembles coryza or a viral infection. ALL also has the following features:
Weakness and sluggishness all over
Muscle, joint, and bone pain that isn’t specific
Anaemia
Petechiae and unexplained bruising
Oedema
Lymphadenopathy
HepatosplenomegalyThe following are typical features of a full blood count in patients with ALL:
Anaemia (normocytic or macrocytic)
Leukopenia affects about half of the patients (WCC 4 x 109/l).
Around 25% of patients have leucocytosis (WCC > 10 x 109/l).
Around 25% of patients have hyperleukocytosis (WCC > 50 x 109/l).
Thrombocytopaenia -
This question is part of the following fields:
- Haematology
- Pathology
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Question 19
Correct
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Glucagon may be used as an antidote for overdose with which of the following:
Your Answer: Beta blockers
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:
Glycogenolysis
Gluconeogenesis
Lipolysis in adipose tissue
The secretion of glucagon is also stimulated by:
Adrenaline
Cholecystokinin
Arginine
Alanine
Acetylcholine
The secretion of glucagon is inhibited by:
Insulin
Somatostatin
Increased free fatty acids
Increased 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
- Pharmacology
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Question 20
Incorrect
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A patient presents with increased breathlessness and worsening of his chronic cough and. He has a chronic lung disorder and is on long-term oxygen therapy (LTOT). Which of these is an indication for LTOT?
Your Answer: A patient with severe chronic asthma with a PaO2 of 8.0 kPa when stable
Correct Answer: A non-smoker with COPD and a PaO2 of 7.5 kPa when stable with secondary polycythaemia
Explanation:Long-term administration of oxygen, usually at least 15 hours daily, improves survival in COPD patients who have severe hypoxaemia.
Long-term oxygen therapy should be considered in:
A non-smoker with COPD and a PaO2<7.3 kPa when stable
A non-smoker with COPD and PaO27.3–8 kPa when stable and with secondary polycythaemia, peripheral oedema, or evidence of pulmonary hypertension
Severe chronic asthma with PaO2<7.3 kPa or persistent disabling breathlessness
A patient with Interstitial lung disease with PaO2<8 kPa and in patients with PaO2>8 kPa with disabling dyspnoea
A patient with cystic fibrosis when PaO2<7.3 kPa or if PaO27.3–8 kPa in the presence of secondary polycythaemia, nocturnal hypoxaemia, pulmonary hypertension, or peripheral oedema
Pulmonary hypertension, without parenchymal lung involvement when PaO2<8 kPa
Neuromuscular or skeletal disorders, after specialist assessment
Obstructive sleep apnoea despite continuous positive airways pressure therapy, after specialist assessment
Pulmonary malignancy or other terminal disease with disabling dyspnoea
Heart failure with daytime PaO2<7.3 kPa when breathing air or with nocturnal hypoxaemia
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This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 21
Correct
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A 40-year-old woman presents with a fever and headache upon returning from an overseas business trip. Upon further investigation, a diagnosis of Plasmodium falciparum malaria was made.
All of the following statements is considered true regarding Plasmodium falciparum malaria, except:Your Answer: It is commonly the result of travel in the Indian subcontinent
Explanation:The mean incubation period for P. falciparum is 12 days.
WHO World Malaria Report 2019 states that an estimated 228 million cases of malaria occurred worldwide in 2018, and reports steadily decreasing the number of cases since 2010. In 2018, nineteen sub-Saharan African countries and India carried approximately 85% of the global malaria burden. The most prevalent and pathogenic malaria parasite, most commonly associated with severe illness and death, especially in the WHO African region, accounting for 99.7% malaria cases, is P. falciparum.
The vector for Plasmodium spp. is a female Anopheles mosquito that inoculates sporozoites contained in her salivary glands into the puncture wound when feeding. Sporozoites enter peripheral bloodstream and are uptake by hepatocytes, where they undergo an asexual pre-erythrocytic liver-stage as liver schizonts lasting up to 2 weeks before the onset of the blood stage.
Intravenous or intramuscular artesunate is the first-line treatment in all patients worldwide and should be used for at least 24 hours and until the oral medication is tolerated.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 22
Correct
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A patient is sent in by her GP with suspected ectopic pregnancy. Tubal ectopic pregnancies occur most commonly in which part of the uterine tube:
Your Answer: Ampulla
Explanation:Ectopic pregnancy most commonly occurs in the ampulla (70% of cases).
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 23
Incorrect
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Which of the following is NOT a common myeloma laboratory finding:
Your Answer: Elevated ESR
Correct Answer: Elevated serum Bence-Jones protein
Explanation:Myeloma laboratory findings include:
– The presence of a paraprotein in serum or urine (the paraprotein is IgG in 60 percent of cases, IgA in 20 percent, and light chain only in almost all the rest),
– Increased serum immunoglobulin-free light chain proteins generated by plasma cells but not coupled with heavy chainsÂ
– Reduced IgG, IgA, and IgM levels in the blood (immune paresis)
– Anaemia, whether normochromic, normocytic, or macrocytic.Â
– On a blood film, a Rouleaux formation has been marked.
– In advanced illness, neutropenia and thrombocytopenia are common.
– ESR is high.
– Plasma cells in the bone marrow are overabundant, typically in aberrant forms. – Hypercalcemia
– Creatinine levels are high.
– Serum albumin levels are low in advanced illness.
60 percent of patients have osteolytic lesions, osteoporosis, or pathological fractures. -
This question is part of the following fields:
- Haematology
- Pathology
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Question 24
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 25
Correct
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You are planning on starting antibiotic therapy for a patient with a diagnosis of gonorrhoea.
Which of these is the MOST appropriate antibiotic combination?Your Answer: Ceftriaxone and azithromycin
Explanation:Currently, ceftriaxone in combination with azithromycin or doxycycline is the combination of antibiotics used in the treatment of gonorrhoea.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 26
Correct
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A 23-year-old has a known diagnosis of HIV. Blood is sent to the laboratory for tests.
AIDS be diagnosed at a CD4 counts below?Your Answer: 200 cells/mm 3
Explanation:A normal CD4 count ranges from 500-1000 cells/mm3.
At CD4 count of less than 350 cells/mm3 treatment with anti-retroviral therapy should be considered.
At a CD4 count of >200 cells/mm3 AIDS is diagnosed.
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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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Which statement regarding skeletal muscle is true?
Your Answer: Actin is the major constituent of the thick filament
Correct 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 28
Incorrect
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Which of these is NOT a lithium side effect:
Your Answer: Hyperthyroidism
Correct Answer: Peptic ulcer disease
Explanation:Adverse Effects of lithium Include
Leucocytosis (most patients)
Polyuria/polydipsia (30-50%)
Dry mouth (20-50%)
Hand tremor (45% initially, 10% after 1 year of treatment)
Confusion (40%)
Decreased memory (40%)
Headache (40%)
Muscle weakness (30% initially, 1% after 1 year of treatment)
Electrocardiographic (ECG) changes (20-30%)
Nausea, vomiting, diarrhoea (10-30% initially, 1-10% after 1-2 years of treatment)
Hyperreflexia (15%)
Muscle twitch (15%)
Vertigo (15%)
Extrapyramidal symptoms, goitre (5%)
Hypothyroidism (1-4%)
Acne (1%)
Hair thinning (1%) -
This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 29
Incorrect
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Which of the following is a primary action of calcitonin:
Your Answer: Inhibition of PTH secretion from the parathyroid glands
Correct Answer: Decreased bone resorption through inhibition of osteoclast activity
Explanation:Calcitonin is a 32 amino acid polypeptide that is primarily synthesised and released by the parafollicular cells (C-cells) of the thyroid gland in response to rising or high levels of plasma Ca2+ions. Its primary role is to reduce the plasma calcium concentration, therefore opposing the effects of parathyroid hormone.
Secretion of calcitonin is stimulated by:
– Increased plasma calcium concentration
– Gastrin
– Pentagastrin
– The main actions of calcitonin are:
– Inhibition of osteoclastic activity (decreasing calcium and phosphate resorption from bone)
– Stimulation of osteoblastic activity
– Decreases renal calcium reabsorption
– Decreases renal phosphate reabsorption -
This question is part of the following fields:
- Endocrine
- Physiology
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Question 30
Correct
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A 5-year-old girl is brought into the Paediatric ER for acute seizures. She has been convulsing for the past 18 minutes now and was already two doses of lorazepam in the ambulance. Now, you prepare a phenytoin infusion to abolish the seizures.
According to the APLS algorithm, what dose of phenytoin is advised for a convulsing child at this stage?Your Answer: 20 mg/kg over 20 minutes
Explanation:Advanced paediatric life support (APLS) recommends phenytoin as the first choice for second-line anticonvulsant in a patient that continues to seize ten minutes after the second dose of the first-line anticonvulsant (benzodiazepine). (step 3 of the APLS algorithm)
The recommended dose of phenytoin infusion is up at 20 mg/kg over 20 minutes. If the patient has already taken phenytoin as maintenance therapy or is allergic to phenytoin, then a phenobarbitone infusion should be set up at 20 mg/kg over 30-60 minutes.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 31
Incorrect
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A 64-year-old man presents with an acute episode of gout. He has a history of chronic heart failure and hypertension. His current medications include ramipril and furosemide.
Which of the following statements regarding the treatment of gout is true? Select ONE answer only.Your Answer: Allopurinol is an effective treatment for acute gout
Correct Answer: Colchicine has a role in prophylactic treatment
Explanation:In the absence of any contra-indications, high-dose NSAIDs are the first-line treatment for acute gout. Naproxen 750 mg as a stat dose followed by 250 mg TDS is a commonly used and effective regime.
Aspirin should not be used in gout as it reduces the urinary clearance of urate and interferes with the action of uricosuric agents. Naproxen, Diclofenac or Indomethacin are more appropriate choices.
Allopurinol is used prophylactically, preventing future attacks by reducing serum uric acid levels. It should not be started in the acute phase as it increases the severity and duration of symptoms.
Colchicine acts on the neutrophils, binding to tubulin to prevent neutrophil migration into the joint. It is as effective as NSAIDs in relieving acute attacks. It also has a role in prophylactic treatment if Allopurinol is not tolerated.
NSAIDs are contra-indicated in heart failure as they can cause fluid retention and congestive cardiac failure. Colchicine is the preferred treatment in patients with heart failure or those who are intolerant of NSAIDs. -
This question is part of the following fields:
- Musculoskeletal Pharmacology
- Pharmacology
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Question 32
Incorrect
-
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: Pericarditis
Correct 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) Malignancy
3) Pericarditis
4) 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 33
Correct
-
A 26-year-old male presents to your clinic with the complaint of recurrent fevers over the past three months. On documentation of the fever, it is noted that the fever increases and decreases in a cyclical pattern over a 1-2 week period. After the appropriate investigations, a diagnosis of Pel-Ebstein fever is made.
Which ONE of the following conditions is most likely to cause this patient's fever?Your Answer: Hodgkin lymphoma
Explanation:The release of cytokines from Reed-Sternberg cells can cause fever in patients with Hodgkin lymphoma, which increases and decreases in a cyclical pattern of 1 to 2 weeks. This is called Pel-Ebstein or Ebstein-Cardarelli fever, specifically seen in Hodgkin lymphoma. The fever is always high grade and can reach 40 degrees or higher.
Cyclical fever in other conditions is common but is not termed as Pel-Ebstein fever. This term is reserved only with Hodgkin lymphoma.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 34
Incorrect
-
In the Kaplan-Meier plot, which of the following labels should be applied to the X-axis?
Your Answer: Odds ratio
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 35
Incorrect
-
Compression of this nerve can cause weakness in the left leg while walking and thigh adduction weakness at the hip joint.
Your Answer: Sciatic nerve
Correct Answer: Obturator nerve
Explanation:The obturator nerve is a sensory and motor nerve that emerges from the lumbar plexus and innervates the thigh.
This nerve supplies motor innervation to the medial compartment of the thigh, making it necessary for thigh adduction.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 36
Incorrect
-
Regarding cytotoxic T cells, which of the following statements is CORRECT:
Your Answer: They only recognise antigen in associated with HLA class II molecules.
Correct Answer: They kill target cells by inducing cell apoptosis.
Explanation:CD8+ T-cells (Cytotoxic T cells)
Recognise antigen only in association with HLA Class I molecules (found on all nucleated cells; present endogenous antigens such as those found in cells infected by viruses or intracellular bacteria.)
Comprise about 25% of peripheral T-cells
Responsible for cytotoxic killing of target cells -
This question is part of the following fields:
- Immune Responses
- Pathology
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Question 37
Incorrect
-
A 24-year-old student with red and painful right eye presents. Conjunctival erythema, mucopurulent discharge and lid crusting are seen on examination, and patient denies presence of itching of the eye. All his observations are normal, he has no fever and is otherwise well.
Which of these is the most likely causative organism?
Your Answer: Staphylococcus epidermidis
Correct Answer: Haemophilus influenzae
Explanation:The most frequent cause of red eye is conjunctivitis. It is caused by inflammation of the conjunctiva which can be infective or allergic and accounts for about 35% of all eye problems presenting to general practice.
Viral conjunctivitis is commonly caused by adenoviruses and it is the most common infectious conjunctivitis.
The common bacterial causes of conjunctivitis are Haemophilus influenzae, Streptococcus pneumoniae, and Staphylococcus aureus.
The clinical features of infective conjunctivitis include:
Acute onset of conjunctival erythema
Feeling ‘grittiness’, ‘foreign body’ or ‘burning’ sensation in the eye.
Watering and discharge which may cause transient blurring of visionThe discharge for viral conjunctivitis is less than that of bacterial conjunctivitis and usually watery.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 38
Incorrect
-
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.
Which of the following is considered the best diagnosis for the case presented above?Your Answer:
Correct Answer: Medial medullary syndrome
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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Question 39
Incorrect
-
What is the average healing time for a femoral shaft fracture under normal circumstances? Choose ONE answer.
Your Answer:
Correct Answer: 12 weeks
Explanation:The process of fracture healing occurs naturally after traumatic bone disruption and begins with haemorrhage, then progresses through Inflammatory, reparative, and remodelling stages
Average healing times of common fractures are:
Femoral shaft: 12 weeks
Tibia: 10 weeks
Phalanges: 3 weeks
Metacarpals: 4-6 weeks
Distal radius: 4-6 weeks
Humerus: 6-8 weeks -
This question is part of the following fields:
- General Pathology
- Pathology
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Question 40
Incorrect
-
At rest, skeletal muscle accounts for between 15-20% of cardiac output and accounts for around 50% of body weight. This can increase to nearly 80% of cardiac output during exercise. Skeletal muscle circulation is highly controlled and has a number of specialized adaptations as a result of this high degree of disparity during exercise, in combination with the diversity in the size of skeletal muscle around the body.
What is the primary mechanism for boosting skeletal muscle blood flow during exercise?
Your Answer:
Correct Answer: Metabolic hyperaemia
Explanation:In skeletal muscle, blood flow is closely related to metabolic rate. Due to the contraction of precapillary sphincters, most capillaries are blocked off from the rest of the circulation at rest and are not perfused. This causes an increase in vascular tone and vessel constriction. As metabolic activity rises, this develops redundancy in the system, allowing it to cope with greater demand. During exercise, metabolic hyperaemia, which is induced by the release of K+, CO2, and adenosine, recruits capillaries. Sympathetic vasoconstriction in the active muscles is overridden by this. Simultaneously, blood flow in non-working muscles is restricted, preserving cardiac output. During exercise, muscle contractions pump blood through the venous system, raising the pressure differential between arterioles and venules and boosting blood flow via capillaries.
Capillary angiogenesis is evident when muscles are used repeatedly (e.g. endurance training). It is a long-term effect, not a quick fix for increased blood flow.
The local partial pressure of alveolar oxygen is the primary intrinsic control of pulmonary blood flow (pAO2). Low pAO2 promotes arteriole vasoconstriction and vice versa. The hypoxic pulmonary vasoconstriction (HPV) reflex allows blood flow to be diverted away from poorly ventilated alveoli and towards well-ventilated alveoli in order to maximize gaseous exchange.
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This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
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Question 41
Incorrect
-
An analytical cohort study is done to compare the relationship between omega 3 intake and occurrence of myocardial infarction (MI) among males aged over 65 years. The following are the data from the study:
No. of subjects taking placebo: 100 men
No. of subjects taking placebo who suffered an MI: 15 men
No. of subjects taking omega 3: 100 men
No. of subjects taking omega 3 who suffered an MI: 5 men
Compute for the relative risk of the study.Your Answer:
Correct Answer: 0.33
Explanation:Relative risk (RR) is a ratio of the probability of an event occurring in the exposed group versus the probability of the event occurring in the non-exposed group.
RR can be computed as the absolute risk of events in the treatment group (ART), divided by the absolute risk of events in the control group (ARC).
RR = ART/ARC
RR = (5/100) / (15/100)
RR = 0.33 -
This question is part of the following fields:
- Evidence Based Medicine
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Question 42
Incorrect
-
All these structures make up the portal triad EXCEPT?
Your Answer:
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 43
Incorrect
-
The term cardiac output refers to the amount of blood pumped by the heart in one minute. The rate in women is around 5 L/min, whereas in men is somewhat higher, around 5.5 L/min.
Which of the equations below best describes cardiac output?
Your Answer:
Correct Answer: Stroke volume x heart rate
Explanation:Cardiac output (CO) is calculated by multiplying stroke volume (SV) by heart rate (HR):
CO = HR x SVAs a result, both stroke volume and heart rate are exactly proportional to cardiac output. There will be an increase in cardiac output if the stroke volume or heart rate increases, and a reduction in cardiac output if the stroke volume or heart rate lowers.
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This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
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Question 44
Incorrect
-
Regarding iron deficiency anaemia, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: Dietary insufficiency is the most common cause of iron deficiency anaemia in adult men in the UK.
Explanation:Blood loss from the gastrointestinal (GI) tract is the most common cause of iron deficiency anaemia in adult men and postmenopausal women.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 45
Incorrect
-
Since the fluid that enters the loop of Henle is isotonic, what is its estimated osmolality?
Your Answer:
Correct Answer: 300 mOsm
Explanation:The loop of Henle connects the proximal tubule to the distal convoluted tubule and lies parallel to the collecting ducts. It is consists of three major segments, the thin descending limb, the thin ascending limb, and the thick ascending limb.
The segments are differentiated based on structure, anatomic location, and function. The main action of the loop of Henle is to recover water and sodium chloride from urine. The liquid entering the loop of Henle is a solution of salt, urea, and other substances traversed along by the proximal convoluted tubule, from which most of the dissolved components are needed by the body, particularly glucose, amino acids, and sodium bicarbonate that have been reabsorbed into the blood.
This fluid is isotonic. Isotonic fluids generally have an osmolality ranging from 270 to 310 mOsm/L. With the fluid that enters the loop of Henle, it is estimated to be 300 mOsm/L. However, after passing the loop, fluid entering the distal tubule is hypotonic to plasma since it has been diluted during its passage.
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 46
Incorrect
-
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:
Correct 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 secretion
Parietal cells/ Hydrochloric acid/ Kills microbes and activates pepsinogen
Parietal cells/ Intrinsic factor/Binds to vitamin B12 and facilitates its absorption
Chief cells/ Pepsinogen/ Protein digestion
Chief cells/ Gastric lipase/ Fat digestion
G-cells/ Gastrin/ Stimulates gastric acid secretion
Enterochromaffin-like cells (ECL cells) /Histamine/ Stimulates gastric acid secretion
Mucous-neck cells/ Mucous and bicarbonate/ Protects stomach epithelium from acid
D-cells/ Somatostatin/ Inhibits gastric acid secretion -
This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 47
Incorrect
-
Insulin is a very important peptide hormone produced by the islets of Langerhans in the pancreas.
Insulin is synthesised by which of the following cell types within the islets of Langerhans? Select ONE answer only.Your Answer:
Correct Answer: Beta cells
Explanation:Insulin is produced by beta cells, located centrally within the islets of Langerhans, in the endocrine tissues of the pancreas. Insulin is a polypeptide hormone consisting of two short chains (A and B) linked by disulphide bonds. Proinsulin is synthesised as a single-chain peptide. Within storage granules, a connecting peptide (C peptide) is removed by proteases to yield insulin. Insulin release is stimulated initially during eating by the parasympathetic nervous system and gut hormones such as secretin, but most output is driven by the rise in plasma glucose concentration that occurs after a meal. The effects of insulin are mediated by the receptor tyrosine kinase.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 48
Incorrect
-
The neurotransmitter in the synaptic cleft is either eliminated or deactivated after the postsynaptic cell responds to the neurotransmitter.
Which of the following enzymes catalyses the breakdown of noradrenaline?Your Answer:
Correct Answer: Catechol-O-methyltransferase (COMT)
Explanation:The neurotransmitter in the synaptic cleft is either eliminated or deactivated after the post-synaptic cell responds to the neurotransmitter.
This can be accomplished in a variety of ways:
Re-uptake
Breakdown
DiffusionSerotonin is an example of a neurotransmitter that is uptake. Serotonin is absorbed back into the presynaptic neuron via the serotonin transporter (SERT), which is found in the presynaptic membrane. Re-uptake neurotransmitters are either recycled by repackaging into vesicles or broken down by enzymes.
Specific enzymes found in the synaptic cleft can also break down neurotransmitters. The following enzymes are examples of these enzymes:
Acetylcholinesterase (AChE) catalyses the acetylcholine breakdown (ACh)
The enzyme catechol-O-methyltransferase (COMT) catalyses the breakdown of catecholamines like adrenaline , dopamine and noradrenaline.The breakdown of catecholamines, as well as other monoamines like serotonin, tyramine, and tryptamine, is catalysed by monoamine oxidases (MOA).
Diffusion of neurotransmitters into nearby locations can also be used to eliminate them. -
This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 49
Incorrect
-
A 62-year-old woman presents with cold sensitivity, tiredness, and weight gain. A series of blood tests done shows a grossly elevated TSH level and a diagnosis of hypothyroidism is made.
What is the commonest cause of hypothyroidism worldwide?Your Answer:
Correct Answer: Iodine deficiency
Explanation:Hypothyroidism occurs when there is a deficiency of circulating thyroid hormones. It is commoner in women and is most frequently seen in the age over 60.
Iodine deficiency is the commonest cause of hypothyroidism worldwide.
In developed countries, iodine deficiency is not a problem and autoimmune thyroiditis is the commonest cause.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 50
Incorrect
-
An ambulance transports a 40-year-old man to the hospital. He ingested a significant amount of aspirin.
In the early stages of an aspirin overdose, which form of acid-base problem should you anticipate?Your Answer:
Correct Answer: Respiratory alkalosis
Explanation:When you take too much aspirin, you have a mix of respiratory alkalosis and metabolic acidosis. Respiratory centre stimulation produces hyperventilation and respiratory alkalosis in the early phases. The direct acid actions of aspirin tend to create a higher anion gap metabolic acidosis in the latter phases.
Below summarizes some of the most common reasons of acid-base abnormalities:Respiratory alkalosis:
– Hyperventilation (e.g. anxiety, pain, fever)
– Pulmonary embolism
– Pneumothorax
– CNS disorders (e.g. CVA, SAH, encephalitis)
– High altitude
– Pregnancy
– Early stages of aspirin overdoseRespiratory acidosis:
– COPD
– Life-threatening asthma
– Pulmonary oedema
– Respiratory depression (e.g. opiates, benzodiazepines)
РNeuromuscular disease (e.g. Guillain-Barr̩ syndrome, muscular dystrophy
– Incorrect ventilator settings (hypoventilation)
– ObesityMetabolic alkalosis:
– Vomiting
– Cardiac arrest
– Multi-organ failure
– Cystic fibrosis
– Potassium depletion (e.g. diuretic usage)
– Cushing’s syndrome
– Conn’s syndromeMetabolic acidosis (with raised anion gap):
– Lactic acidosis (e.g. hypoxaemia, shock, sepsis, infarction)
– Ketoacidosis (e.g. diabetes, starvation, alcohol excess)
– Renal failure
– Poisoning (e.g. late stages of aspirin overdose, methanol, ethylene glycol)Metabolic acidosis (with normal anion gap):
– Renal tubular acidosis
– Diarrhoea
– Ammonium chloride ingestion
– Adrenal insufficiency -
This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 51
Incorrect
-
Which of the following statements is correct regarding the neuronal action potential?
Your Answer:
Correct Answer: Initial depolarisation occurs as a result of a Na + influx.
Explanation:The resting potential in most neurons has a value of approximately -70 mV.
The threshold potential is generally around -55 mV.
Initial depolarisation when there is Na+influx through ligand-gated Na+channels.
Action potential is an all or nothing response. The size of the action potential is constant and so, the intensity of the stimulus is coded by the frequency of firing of a neuron.
K+efflux is responsible for repolarisation. -
This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 52
Incorrect
-
What is the approximate lifespan of the mature erythrocyte:
Your Answer:
Correct Answer: 120 days
Explanation:Erythrocytes have a normal lifespan of about 120 days. Mature erythrocytes are biconcave discs with no nucleus, ribosomes or mitochondria but with the ability to generate energy as ATP by the anaerobic glycolytic pathway. The red cell membrane consists of a bipolar lipid layer with a membrane skeleton of penetrating and integral proteins anchoring carbohydrate surface antigens. The shape and flexibility of red cells allows them to deform easily and pass through capillaries.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 53
Incorrect
-
You are calculating the anion gap on a patient with an acid-base disturbance and you find the anion gap to be low. Which of the following is the most likely cause for the low anion gap:
Your Answer:
Correct Answer: Hypoalbuminaemia
Explanation:A low anion gap is frequently caused by hypoalbuminemia. Albumin is a negatively charged protein and its loss from the serum results in the retention of other negatively charged ions such as chloride and bicarbonate. As bicarbonate and chloride anions are used to calculate the anion gap, there is a subsequent decrease in the gap. The anion gap is sometimes reduced in multiple myeloma, where there is an increase in plasma IgG (paraproteinaemia).
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This question is part of the following fields:
- Physiology
- Renal
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Question 54
Incorrect
-
A 40-year-old male visits his family physician with the complaint of a high-grade fever for the past five days. A complete blood count report shows the presence of neutrophilia.
Which one of the following facts regarding neutrophilia is accurate?Your Answer:
Correct Answer: It can be caused by eclampsia
Explanation:A total neutrophil count of greater than 7.5 x 109/L is called neutrophilia. Typhoid fever usually causes leukopenia or neutropenia. Both localised and generalised bacterial infections can cause neutrophilia.
Metabolic disorders such as
– gout
– eclampsia
– uraemia
can also cause neutrophilia.Acute neutrophilia, in which immature neutrophils can be seen, is referred to as a left shift and can be seen in conditions such as appendicitis.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 55
Incorrect
-
Where does angiotensin II directly act on the renal nephron:
Your Answer:
Correct Answer: Proximal tubule
Explanation:Angiotensin II acts to directly increase Na+reabsorption from the proximal tubule (by activating Na+/H+antiporters).
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This question is part of the following fields:
- Physiology
- Renal
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Question 56
Incorrect
-
A 70-year-old patient develops bacteraemia following peripheral cannulation.
Which of these bacteria is the most likely cause of the infection?Your Answer:
Correct Answer: Staphylococcus epidermidis
Explanation:The commonest implicated organisms in hospital-acquired bacteraemia following cannulation are Staphylococcus aureus and Staphylococcus epidermidis.
The risk is directly proportional to the length of time in-situ. Peripheral cannula should be replaced after 48 hours. -
This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 57
Incorrect
-
A 19-year-old woman presents with dysuria and vaginal discharge. A swab was taken for culture. Culture results showed the presence of Neisseria gonorrhoeae infection. Treatment of azithromycin and doxycycline was started.
Which of the following statements is considered correct regarding Neisseria gonorrhoeae?Your Answer:
Correct Answer: Throat swabs can be used for diagnosis
Explanation:Neisseria gonorrhoeae is a Gram-negative diplococcus that causes gonorrhoea. Gonorrhoea is an acute pyogenic infection of nonciliated columnar and transitional epithelium; infection can be established at any site where these cells are found. Gonococcal infections are primarily acquired by sexual contact and occur primarily in the urethra, endocervix, anal canal, pharynx, and conjunctiva.
In men, acute urethritis, usually resulting in purulent discharge and dysuria (painful urination), is the most common manifestation. The endocervix is the most common site of infection in women. Symptoms of infection, when present, include dysuria, cervical discharge, and lower abdominal pain. Some cases in women may be asymptomatic leading to complications such as pelvic inflammatory disease. Blood-borne dissemination occurs in less than 1% of all infections, resulting in purulent arthritis and rarely septicaemia. Fever and a rash on the extremities can also be present. Other conditions associated with N. gonorrhoeae include anorectal and oropharyngeal infections. Infections in these sites are more common in men who have sex with men but can also occur in women.
Pharyngitis is the chief complaint in symptomatic oropharyngeal infections, whereas discharge, rectal pain, or bloody stools may be seen in rectal gonorrhoea. Approximately 30% to 60% of women with genital gonorrhoea have concurrent rectal infection. Newborns can acquire ophthalmia neonatorum, a gonococcal eye infection, during vaginal delivery through an infected birth canal.
Specimens collected for the recovery of N. gonorrhoeae may come from genital sources or from other sites, such as the rectum, pharynx, and joint
fluid. According to the 2010 STD Treatment guidelines, cephalosporins (e.g., ceftriaxone, cefixime) are currently recommended treatments. -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 58
Incorrect
-
A 62-year-old man complains of chest pain and goes to the emergency room. You diagnose him with an acute coronary syndrome and prescribe enoxaparin as part of his treatment plan.
Enoxaparin inactivates which of the following?Your Answer:
Correct Answer: Thrombin
Explanation:Enoxaparin is a low molecular weight heparin (LMWH) that works in the same way as heparin by binding to and activating the enzyme inhibitor antithrombin III. Antithrombin III inactivates thrombin by forming a 1:1 complex with it. Factor Xa and a few other clotting proteases are also inhibited by the heparin-antithrombin III complex.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 59
Incorrect
-
Which of the following is NOT a typical effect of cortisol:
Your Answer:
Correct Answer: Decreased protein catabolism
Explanation:Cortisol is a steroid hormone produced in the zona fasciculata of the adrenal cortex. It is released in response to stress and low blood glucose concentrations.
Cortisol acts to: raise plasma glucose by stimulating glycolysis and gluconeogenesis in the liver and inhibiting peripheral glucose uptake into storage tissues, increase protein breakdown in skeletal muscle, skin and bone to release amino acids, increase lipolysis from adipose tissues to release fatty acidsand at higher levels and mimic the actions of aldosterone on the kidney to retain Na+ and water and lose K+ ionssuppress the action of immune cells -
This question is part of the following fields:
- Endocrine
- Physiology
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Question 60
Incorrect
-
Through which of the following anatomical structures does an indirect inguinal hernia pass?
Your Answer:
Correct Answer: External oblique
Explanation:Inguinal hernias are subdivided into direct and indirect.
An indirect hernia occurs when abdominal contents protrude through the internal inguinal ring and into the inguinal canal. This occurs lateral to the inferior epigastric vessels. The hernia contents may extend into the scrotum.
A direct inguinal hernia is protrusion of abdominal contents through the transversalis fascia within Hesselbach’s triangle. The borders of Hesselbach’s triangle are the inferior epigastric vessels superolaterally, the rectus sheath medially, and inguinal ligament inferiorly.
The deep (internal) inguinal ring is located above and halfway between the pubic tubercle and the anterior superior iliac spine. This serves as the entrance to the inguinal canal. The superficial (external) inguinal ring lies immediately above and medial to the pubic tubercle. This triangular opening is a defect in the external oblique aponeurosis, and forms the exit of the inguinal canal.
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This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 61
Incorrect
-
Pancreatic ductal alkaline fluid secretion is mainly stimulated by which of the following hormones:
Your Answer:
Correct Answer: Secretin
Explanation:Pancreatic exocrine secretion is controlled by:
Parasympathetic stimulation which enhances secretion of both the enzyme and aqueous components
Sympathetic stimulation which inhibits pancreatic secretion
Secretin which stimulates secretion of the alkaline-rich fluid from ductal cells
Cholecystokinin which stimulates secretion of the enzyme-rich fluid from acinar cellsSomatostatin which inhibits secretion from both acinar and ductal cells
Gastrin which stimulates pancreatic acinar cells to secrete digestive enzymes -
This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 62
Incorrect
-
A 26-year-old man is involved in a motorcycle accident that results in an open fracture of his tibia and fibula. The nerve that innervates peroneus tertius is damaged as a consequence of his injuries.
Peroneus tertius receives its innervation from which of the following nerves? Select ONE answer only.Your Answer:
Correct Answer: Deep peroneal nerve
Explanation:Peroneus brevis is innervated by the superficial peroneal nerve.
Peroneus longus is innervated by the superficial peroneal nerve.
Peroneus tertius is innervated by the deep peroneal nerve. -
This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 63
Incorrect
-
A 58-year-old man presented to the emergency room complaining of a chest pain that has been going on for the past 12 hours. Upon further investigation, a troponin test was ordered and the results came back negative. He was given a discharge order from the emergency department.
Which of the following aspects of this test is considered the most significant in the decision made that it was safe to send the patient home?Your Answer:
Correct Answer: Likelihood ratio
Explanation:The Likelihood Ratio (LR) is the likelihood that a given test result would be expected in a patient with the target disorder compared to the likelihood that that same result would be expected in a patient without the target disorder.
The LR is used to assess how good a diagnostic test is and to help in selecting an appropriate diagnostic tests or sequence of tests. They have advantages over sensitivity and specificity because they are less likely to change with the prevalence of the disorder, they can be calculated for several levels of the symptom/sign or test, they can be used to combine the results of multiple diagnostic test and they can be used to calculate post-test probability for a target disorder.
A LR greater than 1 produces a post-test probability which is higher than the pre-test probability. An LR less than 1 produces a post-test probability which is lower than the pre-test probability. When the pre-test probability lies between 30 and 70 per cent, test results with a very high LR (say, above 10) rule in disease. An LR below 1 produces a post-test probability les than the pre-test probability. A very low LR (say, below 0.1) virtually rules out the chance that the patient has the disease.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 64
Incorrect
-
A 20-year-old male patient lives in a travelling community and has never received any vaccinations. He presents to you with fever.
Which of these statements concerning indications and contraindications for vaccination is TRUE?
Your Answer:
Correct Answer: Inactivated vaccines are safe in pregnancy
Explanation:All vaccines are contraindicated in individuals with: A confirmed anaphylactic reaction to a previous dose of the vaccine or a vaccine containing the same antigens.
A confirmed anaphylactic reaction to a component in the vaccine e.g. neomycinThere is no evidence that vaccinating pregnant women with inactivated vaccine or toxoids harms the woman or foetus.
The current protocol is that a child with history of egg allergy can be safely vaccinated with Fluenz tetra. However, if they had a previous severe anaphylaxis to egg requiring intensive care, then Flenz tetra is contraindicated.
BCG, yellow fever or oral typhoid vaccinations are not safe in HIV positive patients.
The normal times recommended for immunization of full-term babies should also be applied to premature infants and correction for gestational age should not be implemented.
Concurrent antibiotic therapy is not a contraindication to vaccination.
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 65
Incorrect
-
Regarding the foetal oxygen-haemoglobin dissociation curve, which of the following statements is CORRECT:
Your Answer:
Correct Answer: The HbF dissociation curve lies to the left of that for HbA.
Explanation:Foetal haemoglobin (HbF) has a higher affinity for oxygen than adult haemoglobin (HbA) because it’s gamma chains bind 2,3-DPG less avidly than beta chains of HbA. The HbF dissociation curve lies to the left of that for HbA. In the placenta PCO2moves from the foetal to the maternal circulation, shifting the maternal curve further right and the foetal curve further left (the double Bohr effect). The higher affinity of HbF relative to HbA helps transfer oxygen from mother to foetus. Therefore even through blood returning from the placenta to the foetus in the umbilical vein has a PO2of only about 4 kPa, its saturation is 70%. Oxygen transport in the foetus is also helped by a high Hb of about 170 – 180 g/L.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 66
Incorrect
-
A blood culture was performed from a sample taken from a patient. It was noted that a Gram-positive coccus organism was grown.
Among the following microorganisms, which is considered an example of a Gram-positive coccus?Your Answer:
Correct Answer: Staphylococcus aureus
Explanation:Bacillus cereus = Gram-positive bacillus
Neisseria meningitidis = Gram-negative coccus
Salmonella enterica & Escherichia coli = Gram-negative bacilliIn Gram staining, crystal violet is a purple stain that is used to stain the bacteria first. The stained bacteria are decolorized and then stained with a red stain, which is safranin. Bacteria with thick cell walls keep the purple stain and are called Gram-positive. Thin-walled bacteria are easily decolorized so when safranin, the red stain, is placed on the organisms, they become red or Gram-negative.
The Staphylococci that are associated with infections in humans are colonizers of various skin and mucosal surfaces. Because the carrier state is common among the human population, infections are frequently acquired when the colonizing strain gains entrance to a normally sterile site as a result of trauma or abrasion to the skin or mucosal surface. -
This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 67
Incorrect
-
All of the following statements regarding Helicobacter pylori is considered true, except:
Your Answer:
Correct Answer: Serum antibody levels should be used to check for successful eradication
Explanation:Helicobacter pylori is a curved, non-spore forming, Gram-negative bacteria that is primarily linked to gastric infections. Once acquired, it colonizes the stomach for a long time and can cause a low-grade inflammatory process, producing a chronic superficial gastritis.
H. pylori can be recovered from gastric biopsy materials. Samples must be transported quickly to the laboratory.
Helicobacter infections usually are identified by nonculture methods. H. pylori can be presumptively identified in a gastric biopsy specimen by testing for the presence of a rapid urease reaction.Serologic testing is an important screening method for the diagnosis of H. pylori infection. It can also be diagnosed by faecal antigen detection, microscopic examination of stained gastric tissue, and DNA amplification tests.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 68
Incorrect
-
Common causes of exudates are infection, pericarditis, and malignancy.
Which one statement about exudates is true?Your Answer:
Correct Answer: LDH levels are usually high
Explanation:An exudate is an inflammatory fluid emanating from the intravascular space due to changes in the permeability of the surrounding microcirculation.
Exudates are cloudy. It has high LDH levels, serum protein ratio >0.5, protein content >2.9g/dl, specific gravity of >1.020 and a serum-ascites albumin gradient (SAAG) of <1.2g/dl.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 69
Incorrect
-
What is the mechanism of action of captopril:
Your Answer:
Correct Answer: Inhibition of the conversion of angiotensin I to angiotensin II
Explanation:Angiotensin-converting enzyme inhibitors (ACE inhibitors) e.g. captopril inhibit the conversion of angiotensin I to angiotensin II, and thus have a vasodilatory effect, lowering both arterial and venous resistance. The cardiac output increases and, because the renovascular resistance falls, there is an increase in renal blood flow. This latter effect, together with reduced aldosterone release, increases Na+ and H2O excretion, contracting the blood volume and reducing venous return to the heart.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 70
Incorrect
-
A 22-year-old man arrives at the emergency department with a sore throat, low-grade fever, and malaise. His partner has infectious mononucleosis, which was recently diagnosed. In this situation, which of the following cells is the most proliferative:
Your Answer:
Correct Answer: Lymphocytes
Explanation:Histologic findings in EBV infectious mononucleosis: Oropharyngeal epithelium demonstrates an intense lymphoproliferative response in the cells of the oropharynx. The lymph nodes and spleen show lymphocytic infiltration primarily in the periphery of a lymph node.
Relative lymphocytosis (≥ 60%) plus atypical lymphocytosis (≥ 10%) are the characteristic findings of Epstein Barr virus (EBV) infectious mononucleosis. -
This question is part of the following fields:
- Immune Responses
- Pathology
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Question 71
Incorrect
-
A patient suffers a stab wound to the neck. The entry point of the blade is situated within the anterior triangle of the neck.
Which of the following muscles is most likely to be involved? Select ONE answer only.Your Answer:
Correct Answer: Sternothyroid
Explanation:The anterior triangle is the triangular area of the neck found anteriorly to the sternocleidomastoid muscle. It is formed by the anterior border of sternocleidomastoid laterally, the median line of the neck medially and by the inferior border of the mandible superiorly. The apex of the anterior triangle extends towards the manubrium sterni. The anterior triangle contains:
Muscles: thyrohyoid, sternothyroid, sternohyoid muscles
Organs: thyroid gland, parathyroid glands, larynx, trachea, esophagus, submandibular gland, caudal part of the parotid gland
Arteries: superior and inferior thyroid, common carotid, external carotid, internal carotid artery (and sinus), facial, submental, lingual arteries
Veins: anterior jugular veins, internal jugular, common facial, lingual, superior thyroid, middle thyroid veins, facial vein, submental vein, lingual veins
Nerves: vagus nerve (CN X), hypoglossal nerve (CN XII), part of sympathetic trunk, mylohyoid nerveThe posterior triangle is a triangular area found posteriorly to the sternocleidomastoid muscle. It has three borders; anterior, posterior and inferior borders. The anterior border is the posterior margin of the sternocleidomastoid muscle. The posterior border is the anterior margin of the trapezius muscle, while the inferior border is the middle one-third of the clavicle. The investing layer of deep cervical fascia and integument forms the roof of the space, while the floor is covered with the prevertebral fascia along with levator scapulae, splenius capitis and the scalene muscles. The inferior belly of omohyoid subdivides the posterior triangle into a small supraclavicular, and a large occipital, triangle.
Contents:
Vessels: the third part of the subclavian artery, suprascapular and transverse cervical branches of the thyrocervical trunk, external jugular vein, lymph nodes
Nerves: accessory nerve (CN XI), the trunks of the brachial plexus, fibers of the cervical plexus -
This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 72
Incorrect
-
The juxtacapillary receptors, or J receptors, are sensory cells that play an important role in the control of respiration.
At which of the following anatomical sites are the J receptors located? Select ONE answer only.Your Answer:
Correct Answer: The alveolar walls
Explanation:Juxtacapillary receptors (J receptors) are sensory cells that are located within the alveolar walls in juxtaposition to the pulmonary capillaries of the lung.
The J receptors are innervated by the vagus nerve and are activated by physical engorgement of the pulmonary capillaries or increased pulmonary interstitial volume, for example, in the presence of pulmonary oedema, pulmonary embolus, pneumonia and barotraumas. They may also be stimulated by hyperinflation of the lung.
Stimulation of the J receptors causes a reflex increase in breathing rate and is also thought to be involved in the sensation of dyspnoea. The reflex response that is produced is apnoea, followed by rapid breathing, bradycardia, and hypotension. -
This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 73
Incorrect
-
A 25-year-old man suffers from a shoulder injury that damaged the nerve that innervates the infraspinatus muscle.
Which of the following nerves may most likely be affected?Your Answer:
Correct Answer: The suprascapular nerve
Explanation:The suprascapular nerve (C5-C6) innervates the infraspinatus. It originates at the superior trunk of the brachial plexus. It runs laterally across the lateral cervical region to supply the infraspinatus and also the supraspinatus.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 74
Incorrect
-
All of the following statements are considered true regarding nominal variables, except:
Your Answer:
Correct Answer: The central tendency of a nominal variable is given by its median
Explanation:A nominal variable is a type of variable that is used to name, label or categorize particular attributes that are being measured. It takes qualitative values representing different categories, and there is no intrinsic ordering of these categories.
A nominal variable is one of the 2 types of categorical variables and is the simplest among all the measurement variables. Some examples of nominal variables include gender, name, phone, etc.A nominal variable is qualitative, which means numbers are used here only to categorize or identify objects. They can also take quantitative values. However, these quantitative values do not have numeric properties. That is, arithmetic operations cannot be performed on them. If the variable is nominal, the mode is the only measure of central tendency to use.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 75
Incorrect
-
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:
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 76
Incorrect
-
A 36-year-old man presented to the emergency room after an incident of slipping and falling onto his back and left hip. Upon physical examination, it was noted that he has pain on hip extension, but normal hip abduction.
Which of the following muscles was most likely injured in this case?Your Answer:
Correct Answer: Gluteus maximus
Explanation:The primary hip extensors are the gluteus maximus and the hamstrings such as the long head of the biceps femoris, the semitendinosus, and the semimembranosus. The extensor head of the adductor magnus is also considered a primary hip extensor.
The hip abductor muscle group is located on the lateral thigh. The primary hip abductor muscles include the gluteus medius, gluteus minimus, and tensor fasciae latae.
The secondary hip abductors include the piriformis, sartorius, and superior fibres of the gluteus maximus. -
This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 77
Incorrect
-
The transport of oxygen from maternal to fetal circulation is made possible by fetal haemoglobin. Which of the statements about fetal haemoglobin (HbF) is also correct?
Your Answer:
Correct Answer: The oxygen dissociation curve for foetal haemoglobin is shifted to the left of that of adult haemoglobin
Explanation:Fetal haemoglobin is the most common type of haemoglobin found in the foetus during pregnancy. It transports oxygen from the maternal circulation to the fetal circulation. It can easily bind to oxygen from the maternal circulation because it has a high affinity for oxygen. From 10 to 12 weeks of pregnancy to the first six months after birth, the erythroid precursor cells produce fetal haemoglobin. In comparison to adult haemoglobin, fetal haemoglobin has two alpha and two gamma subunits, whereas adult haemoglobin has two alpha and two beta subunits in its major form.
And, unlike adult haemoglobin, the oxygen dissociation curve of fetal haemoglobin is left-shifted. Myoglobin is an oxygen storage molecule with a very high affinity for oxygen. Only when the partial pressure of oxygen is exceeded does it release oxygen.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 78
Incorrect
-
A 64-year-old lady attends the emergency department with a known brain tumour. Her left eye is directed outwards and downwards, she can't open it, and her pupil is fixed and dilated. The tumour is most likely compressing which of the following structures:
Your Answer:
Correct Answer: Oculomotor nerve
Explanation:The oculomotor nerve is the third cranial nerve. It is the main source of innervation to the extraocular muscles and also contains parasympathetic fibres which relay in the ciliary ganglion. Damage to the third cranial nerve may cause diplopia, pupil mydriasis, and/or upper eyelid ptosis. The clinical manifestations of third cranial nerve dysfunction reflect its constituent parts.
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This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
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Question 79
Incorrect
-
Which of the following statements is true about anterior cord syndrome?
Your Answer:
Correct Answer: There is preservation of proprioception
Explanation:Anterior cord syndrome is an incomplete cord syndrome that predominantly affects the anterior 2/3 of the spinal cord, characteristically resulting in motor paralysis below the level of the lesion as well as the loss of pain and temperature at and below the level of the lesion. The patient presentation typically includes these two findings; however, there is variability depending on the portion of the spinal cord affected. Other findings include back pain, or autonomic dysfunction such as hypotension, neurogenic bowel or bladder, and sexual dysfunction. The severity of motor dysfunction can vary, typically resulting in paraplegia or quadriplegia.
Proprioception, vibratory sense, two-point discrimination, and fine touch are not affected in anterior cord syndrome. These sensations are under the control of the dorsal column of the spinal cord, which is supplied by two posterior spinal arteries running in the posterior lateral sulci.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 80
Incorrect
-
A 23 year old student presents to ED with a widespread maculopapular rash. She recently had a sore throat and was started on a course of antibiotics. The most likely antibiotic that she was prescribed is:
Your Answer:
Correct Answer: Amoxicillin
Explanation:Maculopapular rashes are commonly seen with ampicillin and amoxicillin. However they are not usually related to true penicillin allergy. Very often, they occur in patients with glandular fever and so, broad-spectrum penicillins should not be used blindly, for management and treatment of a sore throat. There is also an increased risk of rash in patients with acute or chronic lymphocytic leukaemia or in cytomegalovirus infection.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 81
Incorrect
-
A patient presents with a necrolytic migratory rash. Her blood serum glucagon concentration is 1246 pg/mL. Following further investigations, she is diagnosed with glucagonoma.
Which SINGLE statement regarding glucagon is true?Your Answer:
Correct Answer: It makes fatty acids available for oxidation
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:
Glycogenolysis
Gluconeogenesis
Lipolysis in adipose tissue
The secretion of glucagon is also stimulated by:
Adrenaline
Cholecystokinin
Arginine
Alanine
Acetylcholine
The secretion of glucagon is inhibited by:
Insulin
Somatostatin
Increased free fatty acids
Increased 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 82
Incorrect
-
The following all cause a right shift in the oxygen dissociation curve EXCEPT for:
Your Answer:
Correct Answer: Foetal haemoglobin
Explanation:A decreased affinity of haemoglobin for oxygen (and hence increased ease of dissociation), shown by a right shift in the oxygen dissociation curve, is caused by a fall in pH, a rise in PCO2(the Bohr effect) and an increase in temperature. These changes occur in metabolically active tissues such as in exercise, and encourage oxygen release. The metabolic by-product 2,3-diphosphoglycerate (2,3 -DPG) also causes a right shift; 2, 3 -DPG may also be raised in chronic anaemia, chronic lung disease, or at high altitude. Foetal haemoglobin (HbF) binds 2, 3 -DPG less strongly than does adult haemoglobin (HbA), and so the HbF dissociation curve lies to the left of that for HbA, reflecting its higher oxygen affinity. This helps transfer oxygen from mother to foetus.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 83
Incorrect
-
Oedema can occur as a result of any of the following WITH THE EXCEPTION OF:
Your Answer:
Correct Answer: Increased interstitial hydrostatic pressure
Explanation:Oedema is defined as a palpable swelling produced by the expansion of the interstitial fluid volume. A variety of clinical conditions are associated with the development of oedema, including heart failure, cirrhosis, and nephrotic syndrome. The development of oedema requires an alteration in capillary dynamics in a direction that favours an increase in net filtration and also inadequate removal of the additional filtered fluid by lymphatic drainage. Oedema may form in response to an elevation in capillary hydraulic pressure (which increases the delta hydraulic pressure) or increased capillary permeability, or it can be due to disruption of the endothelial glycocalyx, decreased interstitial compliance, a lower plasma oncotic pressure (which reduces the delta oncotic pressure), or a combination of these changes. Oedema can also be induced by lymphatic obstruction since the fluid that is normally filtered is not returned to the systemic circulation.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 84
Incorrect
-
Regarding cardiac excitation-contraction coupling, which of the following statements is CORRECT:
Your Answer:
Correct Answer: In relaxation, Ca 2+ is transported out of the cell using energy from a Na + gradient.
Explanation:During the AP plateau, Ca2+enters the cell and activates Ca2+sensitive Ca2+release channels in the sarcoplasmic reticulum allowing stored Ca2+to flood into the cytosol; this is called Ca2+-induced Ca2+release. In relaxation, about 80% of Ca2+is rapidly pumped back into the SR (sequestered) by Ca2+ATPase pumps. The Ca2+that entered the cell during the AP is transported out of the cell primarily by the Na+/Ca2+exchanger in the membrane which pumps one Ca2+ion out in exchange for three Na+ions in, using the Na+electrochemical gradient as an energy source. Increased heart rate increases the force of contraction in a stepwise fashion as intracellular [Ca2+] increases cumulatively over several beats; this is the Treppe effect. Factors that affect intracellular [Ca2+] and hence cardiac contractility are called inotropes.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 85
Incorrect
-
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 86
Incorrect
-
Nifedipine commonly causes which of the following adverse effects?
Your Answer:
Correct 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 87
Incorrect
-
Which of the following clotting factors is NOT vitamin K-dependent:
Your Answer:
Correct Answer: V
Explanation:Fat-soluble vitamin K is obtained from green vegetables and bacterial synthesis in the gut. Deficiency may present in the newborn (haemorrhagic disease of the newborn) or in later life. Deficiency may be caused by an inadequate diet, malabsorption or inhibition of vitamin K by drugs such as warfarin. The activity of factors II, VII, IX and X are vitamin K dependent as well as that of protein C and protein S. Both PT and APTT are prolonged.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 88
Incorrect
-
Which of the following study designs is considered the most appropriate to safely determine whether an association exists between a well-established, commonly used, anti-hypertensive medication and causing type II diabetes mellitus?
Your Answer:
Correct Answer: A meta-analysis
Explanation: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.
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.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 89
Incorrect
-
You're in resus with a 69-year-old woman who is very sick. You decide to contact the intensive care outreach team because she appears to be in septic shock. They decide to start a dobutamine infusion as soon as they arrive.
Which of the following statements about dobutamine is correct?Your Answer:
Correct Answer: It may be infused via a peripheral line
Explanation:Dobutamine is a synthetic isoprenaline derivative that is used to provide inotropic support to patients with low cardiac output caused by septic shock, myocardial infarction, or other cardiac conditions.
Dobutamine is a sympathomimetic drug that stimulates beta-1 adrenergic receptors in the heart to produce its primary effect. As a result, it has inotropic properties that increase cardiac contractility and output. It also has a small amount of alpha1- and beta-2-adrenergic activity.
It is infused intravenously after being diluted to a volume of at least 50 ml in a suitable crystalloid solution. The dose is titrated to response and ranges from 0.5 to 40 g/kg/min. Extravasation-induced skin necrosis is uncommon, and dobutamine can be administered through a peripheral line.
At doses below 10 g/kg/min, side effects are rare, but at higher doses, they can include:
Nausea and vomiting
Tachycardia
Dysrhythmias
Angina
Hypertension
Headache -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 90
Incorrect
-
Regarding disseminated intravascular coagulation (DIC), which of the following statements is INCORRECT:
Your Answer:
Correct Answer: Thrombocytosis results in widespread platelet aggregation.
Explanation:DIC is characterised by a widespread inappropriate intravascular deposition of fibrin with consumption of coagulation factors and platelets. This may occur as a consequence of many disorders that release procoagulant material into the circulation or cause widespread endothelial damage or platelet aggregation. Increased activity of thrombin in the circulation overwhelms its normal rate of removal by natural anticoagulants. In addition to causing increased deposition of fibrin in the microcirculation and widespread platelet aggregation to the vessels, intravascular thrombin formation interferes with fibrin polymerisation. Intense fibrinolysis is stimulated by thrombi on vascular walls and the release of fibrin degradation products again interferes with fibrin polymerisation. The combined action of thrombin and plasmin causes depletion of fibrinogen and all coagulation factors, compounded by thrombocytopaenia caused by platelet consumption.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 91
Incorrect
-
A patient presents to your Emergency Department with a laceration on their buttocks requiring closure with sutures.
What stage of wound healing is the first to reach completion?Your Answer:
Correct Answer: Haemostasis
Explanation:The stages of wound healing are: haemostasis, inflammatory, proliferative and remodelling (maturation) phases in that order. The first stage in the healing process of a laceration is haemostasis. Haemostasis is the process of the wound being closed by clotting.
The inflammatory phase occurs just after and up to 48 hours after injury– Blood vessels dilate to allow white blood cells, antibodies, growth factors, enzymes and nutrients to reach the wounded area leading to the characteristic signs of inflammation seen.
Epithelialisation and angiogenesis are not phases of wound healing but occur during the proliferative phase. This ia after haemolysis and inflammation phases have occurred.
The maturation phase is the final phase and occurs when the wound has closed. It involves remodelling of collagen from type III to type I. Apoptosis remove unwanted cells, cellular activity reduces and the number of blood vessels in the wounded area regresses and decreases. This can continues for up to 1 year after injury.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 92
Incorrect
-
The mechanism of action of abciximab is by:
Your Answer:
Correct Answer: Blocking the binding of fibrinogen to GPIIb/IIIa receptor sites
Explanation:Abciximab is a glycoprotein IIb/IIIa inhibitors and prevents platelet aggregation by blocking the binding of fibrinogen to receptors on platelets.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 93
Incorrect
-
You've been summoned to your Emergency Department resuscitation area to see a patient. You consider giving him an atropine shot because he is severely bradycardic.
Which of the following statements about the use of atropine is correct?Your Answer:
Correct Answer: It blocks the effects of the vagus nerve on both the SA and AV nodes
Explanation:At muscarinic receptors, atropine blocks the action of the parasympathetic neurotransmitter acetylcholine. As a result, it inhibits the vagus nerve’s effects on both the SA and AV nodes, increasing sinus automaticity and facilitating AV node conduction.
At muscarinic receptors, atropine blocks the action of the parasympathetic neurotransmitter acetylcholine. As a result, it inhibits the vagus nerve’s effects on both the SA and AV nodes, increasing sinus automaticity and facilitating AV node conduction.
The most common cause of asystole during cardiac arrest is primary myocardial pathology, not excessive vagal tone, and there is no evidence that atropine is helpful in the treatment of asystole or PEA. As a result, it is no longer included in the ALS algorithm’s non-shockable section. Atropine is most commonly used in the peri-arrest period. It is used to treat bradycardia (sinus, atrial, or nodal) or AV block when the patient’s haemodynamic condition is compromised by the bradycardia.
If any of the following adverse features are present, the ALS bradycardia algorithm recommends a dose of 500 mcg IV:
Shock
Syncope
Myocardial ischaemia
Heart failureAtropine is also used for the following purposes:
Topically as a cycloplegic and mydriatic to the eyes
To cut down on secretions (e.g. in anaesthesia)
Organophosphate poisoning is treated with
Atropine’s side effects are dose-dependent and include:
Mouth is parched
Vomiting and nausea
Vision is hazy
Retention of urine
Tachyarrhythmias
It can also cause severe confusion and hallucinations in patients, especially the elderly. -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 94
Incorrect
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Which of the following is a contraindication to the use of opioid analgesics:
Your Answer:
Correct Answer: Raised intracranial pressure
Explanation:Opioids should be avoided in people who have:
A risk of paralytic ileus (opioids reduce gastric motility)
Acute respiratory depressionAn acute exacerbation of asthma (opioids can aggravate bronchoconstriction as a result of histamine release)
Conditions associated with increased intracranial pressure including head injury (opioids can interfere with pupillary response making neurological assessment difficult and may cause retention of carbon dioxide aggravating the increased intracranial pressure) -
This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 95
Incorrect
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A 35-year-old woman has complaints of nausea, abdominal pain and dark urine. On examination, you notice she has jaundice. She tells you she recently started a new medication.
Which drug is NOT likely to cause cholestatic jaundice out of the following?Your Answer:
Correct Answer: Isoniazid
Explanation:Isoniazid is an antibiotic used in the treatment of tuberculosis. It can cause acute, dose-dependent, hepatitis but is not a recognised cause of cholestatic jaundice.
The drugs that cause cholestatic jaundice are the following:
1. Nitrofurantoin
2. Erythromycin
3. Cephalosporins
4. Verapamil
5. NSAIDs
6. ACE inhibitors
7. Tricyclic antidepressants
8. Phenytoin
9. Azathioprine
10. Carbamazepine
11. Oral contraceptive pills
12. Diazepam
13. Ketoconazole
14. Tamoxifen -
This question is part of the following fields:
- Infections
- Pharmacology
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Question 96
Incorrect
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The functional residual capacity (FRC) will be increased in which of the following:
Your Answer:
Correct Answer: Emphysema
Explanation:Factors increasing FRC:
Emphysema
Air trapping in asthma
Ageing (due to loss of elastic properties)
Increasing height of patient -
This question is part of the following fields:
- Physiology
- Respiratory
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Question 97
Incorrect
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Regarding forest plots, which of the following is the purpose of this graph?
Your Answer:
Correct Answer: To graphically display the relative strength of multiple studies attempting to answer the same question
Explanation:The results of meta-analysis are often displayed graphically in a forest plot. A properly constructed forest plot is the most effective way to graphically display the relative strength of multiple studies attempting to answer the same question. A typical meta-analysis consists of three main objectives that include estimation of effect sizes from individual studies and a pooled summary estimate with their confidence intervals (CIs), heterogeneity among the studies, and any publication bias. The forest plot illustrates the first two of these objectives. Forest plots visualize the effect measure and CI of individual studies, which provide the raw data for the meta-analysis, as well the pooled-effect measure and CI. The individual studies also can be grouped in the forest plot by some of their characteristics for ease of interpretation such as by study size or year of publication. When comparing the outcomes between an intervention and a control group, dichotomous outcome variables are expressed as ratios (i.e. odds ratios, ORs or risk ratios, RRs), while for continuous outcomes, a weighted mean difference is reported.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 98
Incorrect
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Which of the following statements is correct regarding hyponatraemia?
Your Answer:
Correct Answer: Correction of serum sodium that is too rapid can precipitate central pontine myelinolysis.
Explanation:Hyponatraemia refers to a serum sodium concentration < 135 mmol/L.
It is safer to quickly correct acute hyponatremia than chronic hyponatremia but correction should not be too fast, especially in chronic hyponatraemia, because of the risk of central pontine myelinolysis. Hyponatraemia is usually associated with a low plasma osmolality.
Under normal circumstances, if serum osmolality is low, then urine osmolality should also be low because the kidneys should be trying to retain solute.
In SIADH, excess ADH causes water retention, but not the retention of solute. Therefore, urine that is concentrated and relatively high in sodium is produced, even though the serum sodium is low (urine osmolality > 100 mosmol/kg). -
This question is part of the following fields:
- Endocrine
- Physiology
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Question 99
Incorrect
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The action potential is generated by excitable tissues, which are specialized tissues that can generate a meaningful electrical signal. Local currents transport action potentials down the axons of neurons.
Which of the following claims about the action potential's conduction is correct?Your Answer:
Correct Answer: The areas of the membrane that have recently depolarised will not depolarise again due to the refractory period
Explanation:Local currents propagate action potentials down the axons of neurons. Following depolarization, this local current flow depolarizes the next axonal membrane, and when this region crosses the threshold, more action potentials are formed, and so on. Due to the refractory period, portions of the membrane that have recently depolarized will not depolarize again, resulting in the action potential only being able to go in one direction.
The square root of axonal diameter determines the velocity of the action potential; the axons with the biggest diameter have the quickest conduction velocities. When a neuron is myelinated, the speed of the action potential rises as well.
The myelin sheath is an insulating coating that surrounds certain neural axons. By increasing membrane resistance and decreasing membrane capacitance, the myelin coating increases conduction. This enables faster electrical signal transmission via a neuron, making them more energy-efficient than non-myelinated neuronal axons.
Nodes of Ranvier are periodic holes in a myelinate axon when there is no myelin and the axonal membrane is exposed. There are no gated ion channels in the portion of the axon covered by the myelin sheath, but there is a high density of ion channels in the Nodes of Ranvier. Action potentials can only arise at the nodes as a result of this.
Electrical impulses are quickly transmitted from one node to the next, causing depolarization of the membrane above the threshold and triggering another action potential, which is then transmitted to the next node. An action potential is rapidly conducted down a neuron in this manner. Saltatory conduction is the term for this. -
This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 100
Incorrect
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Which anatomical structure is divided following an emergency department anterolateral thoracotomy?
Your Answer:
Correct Answer: Latissimus dorsi
Explanation:Thoracotomy describes an incision made in the chest wall to access the contents of the thoracic cavity. Thoracotomies typically can be divided into two categories; anterolateral thoracotomies and posterolateral thoracotomies. These can be further subdivided into supra-mammary and infra-mammary and, of course, further divided into the right or left chest. Each type of incision has its utility given certain circumstances.
A scalpel is used to sharply divide the skin along the inframammary crease overlying the fifth rib. Electrocautery is then used to divide the pectoralis major muscle and serratus anterior muscle. Visualization of the proper operative field can be achieved with the division and retraction of the latissimus dorsi. Either the fourth or fifth intercostal space is then entered after the division of intercostal muscles above the rib to ensure the preservation of the neurovascular bundle. Once the patient is properly secured to the operating table, the ipsilateral arm is raised and positioned anteriorly and cephalad to rest above the head. The incision is started along the inframammary crease and extended posterolaterally below the tip of the scapula. It is then extended superiorly between the spine and the edge of the scapula, a short distance. The trapezius muscle and the subcutaneous tissues are divided with electrocautery. The serratus anterior and latissimus dorsi muscles are identified and can be retracted. The intercostal muscles are then divided along the superior border of the ribs, and the thoracic cavity is accessed.
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This question is part of the following fields:
- Anatomy
- Thorax
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