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Question 1
Correct
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You contact the intensive care outreach team to inquire about a severely hypotensive resuscitated patient. They make the decision to start a dopamine infusion.
Dopamine primarily has which of the following effects at high doses (>15 g/kg/min)?Your Answer: Alpha-adrenergic stimulation
Explanation:Dopamine is a catecholamine that occurs naturally and is used to treat low cardiac output, septic shock, and renal failure. It is both adrenaline and noradrenaline’s immediate precursor.
Dopamine acts on D1 and D2 dopamine receptors in the renal, mesenteric, and coronary beds at low doses (1-5 g/kg/min). Dopamine causes a significant decrease in renal vascular resistance and an increase in renal blood flow at these doses. Within this dose range, it is also involved in central modulation of behaviour and movement.
Dopamine stimulates beta- and alpha-adrenergic receptors directly and indirectly at higher doses. Beta-stimulation predominates at a rate of 5-10 g/kg/min, resulting in a positive inotropic effect that increases cardiac output and coronary blood flow. Alpha-stimulation predominates at infusion rates greater than 15 g/kg/min, resulting in peripheral vasoconstriction and an increase in venous return and systolic blood pressure.
Because clearance varies greatly in critically ill patients, plasma concentrations cannot be predicted reliably from infusion rates.
Dopamine is given as an intravenous infusion, and because extravasation can cause tissue necrosis and sloughing, a central line is usually used (especially at higher doses >240 g/min). In an emergency, however, dopamine can be administered through a large vein (cephalic or basilic) while a central line is being prepared. Alkaline intravenous solutions inactivate it, so sodium bicarbonate should not be infused with it.The following are the most common dopamine side effects:
Nausea and vomiting
Tachycardia
Dysrhythmias
Angina
Hypertension -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 2
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 3
Correct
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A 78-year-old man complains of lumps in his neck. Several large, non-tender cervical lymph nodes are discovered during your examination.
You arrange for some blood tests, and the results reveal that he has lymphocytosis with a count of 16 x 10 9 /l.
In this case, what is the most likely diagnosis?Your Answer: Chronic lymphocytic leukaemia
Explanation:The most common type of adult leukaemia is chronic lymphocytic leukaemia (CLL). It develops as a result of relatively mature lymphocytes clonally proliferating. The B-cell lineage accounts for approximately 95% of cases. CLL is primarily a disease of adult men, with men over the age of 50 accounting for more than 75% of CLL patients.
It is the most indolent form of chronic leukaemia, and it is frequently discovered by chance when blood counts are taken for other reasons, such as ‘well man’ screening tests. The patient may develop lymphadenopathy, hepatosplenomegaly, anaemia, and infections as the disease progresses.
The following are examples of CLL laboratory findings:
Clonal B cell lymphocytosis (diagnosed at greater than 5 x 109/l, but can reach 300 x 109/l)
In advanced disease, normocytic, normochromic anaemia is present.Patients with autoimmune-related haemolytic anaemias have a positive direct antiglobulin test (DAT).
Although bone marrow aspiration is not always required, it can aid in the diagnosis of CLL. If there has been rapid lymph node enlargement, a lymph node biopsy is required to rule out Richter’s syndrome. This is the transition from low-grade lymphoma to high-grade lymphoma, which is characterised by fever, weight loss, and pain.
Although there is no cure for CLL, it can be managed with chemotherapy regimens that help patients live longer. Early treatment has no benefit, and the standard treatment for early disease is to watch and wait, with examinations and blood counts every 3 to 12 months. Chemotherapy is usually reserved for patients who have a disease that is active and causing symptoms.
The following is the overall prognosis for CLL:
1/3 will not require treatment and will live a long time.
1/3 will go through an indolent phase before the disease progresses.
1/3 of patients will have an aggressive disease that requires immediate treatment. -
This question is part of the following fields:
- Haematology
- Pathology
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Question 4
Correct
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Low levels of which of the following arterial blood gas parameters stimulate the peripheral chemoreceptors?
Your Answer: Arterial pO 2
Explanation:Chemoreceptors are activated when the chemical composition of their immediate surroundings changes.
Peripheral chemoreceptors, together with central chemoreceptors, regulate respiratory functions. They detect changes in arterial blood oxygen levels. Decreased arterial Po2 (partial pressure of oxygen) reflexly stimulates peripheral chemoreceptors.
When peripheral chemoreceptors detect changes in arterial blood oxygen, they will trigger cardiorespiratory changes such as an increase in breathing and blood pressure. These reflexes are important for maintaining homeostasis during hypoxemia.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 5
Incorrect
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What is nimodipine used predominantly in the treatment of?
Your Answer:
Correct Answer: Prevention and treatment of vascular spasm following subarachnoid haemorrhage
Explanation:Nimodipine is a smooth muscle relaxant that is related to nifedipine, but the effects preferentially act on cerebral arteries. It is exclusively used for the prevention and treatment of vascular spasm after an aneurysmal subarachnoid haemorrhage.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 6
Incorrect
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The following are all examples of type II hypersensitivity EXCEPT for:
Your Answer:
Correct Answer: Post-streptococcal glomerulonephritis
Explanation:Examples of type II reactions include:
Incompatible blood transfusions
Haemolytic disease of the newborn
Autoimmune haemolytic anaemias
Goodpasture’s syndrome
Rheumatic heart disease
Bullous pemphigoid -
This question is part of the following fields:
- Immune Responses
- Pathology
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Question 7
Incorrect
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Which of these increases osteoclast activity?
Your Answer:
Correct Answer: Parathyroid hormone
Explanation:Osteoclasts are bone cell that break down bone tissue.
Parathyroid hormone increases osteoclastic activity.
1,25-dihydroxycholecalciferol increases osteoclastic activity
Calcitonin inhibits osteoclastic activity
Bisphosphonates are osteoclast inhibitors.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 8
Incorrect
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The muscles of the soft palate (other than the tensor veli palatini) are innervated by which of the following nerves:
Your Answer:
Correct Answer: Vagus nerve
Explanation:All of the muscles of the soft palate are innervated by the vagus nerve (from the pharyngeal plexus), except for the tensor veli palatini, which is innervated by a branch of the mandibular nerve.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 9
Incorrect
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A 60-year-old female with a past history of rheumatic fever and a prosthetic mitral valve presents to you with fever and an episode of expressive dysphasia that lasted around 30 minutes. There is no history of known drug allergies On examination you note a systolic murmur and you suspect it is infective endocarditis.
Which antibacterial agents would be the most appropriate to prescribe in this case?
Your Answer:
Correct Answer: Vancomycin, rifampicin and gentamicin
Explanation:Endocarditis is infective or non infective inflammation (marantic endocarditis) of the inner layer of the heart and it often involves the heart valves.
Risk factors include:
Prosthetic heart valves
Congenital heart defects
Prior history of endocarditis
Rheumatic fever
Illicit intravenous drug useIn the presentation of endocarditis, the following triad is often quoted:
Persistent fever
Embolic phenomena
New or changing murmurA combination of vancomycin, rifampicin and gentamicin is advised if the patient has a cardiac prostheses, is penicillin allergic, or if methicillin-resistant Staphylococcus aureus (MRSA) is suspected. In this case the patient has a prosthetic valve making this the most appropriate initial treatment regimen.
Flucloxacillin and gentamicin are current recommended by NICE and the BNF for the initial ‘blind’ therapy in endocarditis. This patient has prostheses and this is not the most appropriate initial treatment regimen.
Other features that may be present include heart failure, splenomegaly, finger clubbing, renal features (haematuria, proteinuria, nephritis), and vasculitic features (splinter haemorrhages, Osler’s nodes, Janeway lesions, Roth’s spots).
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 10
Incorrect
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Which of the following statements about propofol is TRUE:
Your Answer:
Correct Answer: Propofol has some antiemetic action.
Explanation:Propofol has some antiemetic properties. It’s for this reason that it’s used to treat postoperative nausea and vomiting. Propofol is mostly processed in the liver, with the kidneys excreting just around 1% of it unaltered. Propofol, unlike thiopental, does not produce tissue necrosis when it is extravasated. Propofol lowers intracranial pressure via lowering brain metabolic rate and cerebral blood flow. Propofol is thought to be safe for people with bronchial asthma and chronic obstructive pulmonary disease.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 11
Incorrect
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Renal potassium excretion is promoted by all but which one of the following:
Your Answer:
Correct Answer: Increased intracellular magnesium
Explanation:Aldosterone: A rise in [K+] in the extracellular fluid of the adrenal cortex directly stimulates aldosterone release. Aldosterone promotes the synthesis of Na+/K+ATPases and the insertion of more Na+/K+ATPases into the basolateral membrane, and also stimulates apical sodium and potassium channel activity, overall acting to increase sodium reabsorption and potassium secretion.
pH changes: Potassium secretion is reduced in acute acidosis and increased in acute alkalosis. A higher pH increases the apical K+channel activity and the basolateral Na+/K+ATPase activity – both changes that promote K+secretion.
Flow rates: Increased flow rates in the collecting duct reduce K+concentration in the lumen and therefore enhance K+secretion. Increased flow also activates BK potassium channels, and ENaC channels which promote potassium secretion and sodium reabsorption respectively.
Sodium delivery: Decreased Na+delivery to the collecting ducts results in less Na+reabsorption and hence a reduced gradient for K+secretion.
Magnesium: Intracellular magnesium can bind and block K+channels inhibiting K+secretion into the tubules. Therefore magnesium deficiency reduces this inhibitory effect and so allows more potassium to be secreted into tubules and can cause hypokalaemia. -
This question is part of the following fields:
- Physiology
- Renal
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Question 12
Incorrect
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A 58-year-old man with a long history of depression presents with a deliberate overdose of verapamil tablets, which he is prescribed for a heart condition.
What is verapamil's mechanism of action?Your Answer:
Correct Answer: L-type calcium channel blockade
Explanation:Overdosing on calcium-channel blockers should always be taken seriously and regarded as potentially fatal. Verapamil and diltiazem are the two most lethal calcium channel blockers in overdose. These work by binding the alpha-1 subunit of L-type calcium channels, preventing calcium from entering the cell. In cardiac myocytes, vascular smooth muscle cells, and islet beta-cells, these channels play an important role.
The standard ABC approach should be used to resuscitate all patients as needed. If life-threatening toxicity is expected, intubation and ventilation should be considered early on. If hypotension and shock are developing, early invasive blood pressure monitoring is recommended.
The primary goal of specific treatments is to support the cardiovascular system. These are some of them:
1. Fluid resuscitation: Give up to 20 mL of crystalloid per kilogramme of body weight.
2. Calcium supplementation
This can be a good way to raise blood pressure and heart rate temporarily.
via central venous access: 10% calcium gluconate 60 mL IV (0.6-1.0 mL/kg in children) or 10% calcium chloride 20 mL IV (0.2 mL/kg in children)
Boluses can be given up to three times in a row.
To keep serum calcium >2.0 mEq/L, consider a calcium infusion.3. Atropine: 0.6 mg every 2 minutes up to 1.8 mg is an option, but it is often ineffective.
4. HIET (high-dose insulin-euglycemic therapy):
The role of HIET in the step-by-step management of cardiovascular toxicity has changed.5. Vasoactive infusions:
This was once thought to be a last-ditch measure, but it is now widely recommended that it be used sooner rather than later.
Insulin with a short half-life 50 mL of 50 percent glucose IV bolus plus 1 U/kg bolus (unless marked hyperglycaemia present)
Short-acting insulin/dextrose infusions should be continued.
Glucose should be checked every 20 minutes for the first hour, then hourly after that.
Regularly check potassium levels and replace if they fall below 2.5 mmol/L.
Titrate catecholamines to effect (inotropy and chronotropy); options include dopamine, adrenaline, and/or noradrenaline infusions.6. Sodium bicarbonate: Use 50-100 mEq sodium bicarbonate (0.5-1.0 mEq/kg in children) in cases where a severe metabolic acidosis develops.
7. Cardiac pacing: It can be difficult to achieve electrical capture, and it may not improve overall perfusion.
Bypass AV blockade with ventricular pacing, which is usually done at a rate of less than 60 beats per minute.8. Intralipid transport
Calcium channel blockers are lipid-soluble agents, so they should be used in refractory cases. -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 13
Incorrect
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Which of the following drugs used in the management of hyperkalaemia does not affect serum potassium levels:
Your Answer:
Correct Answer: Calcium gluconate
Explanation:Calcium gluconate is given to antagonise cardiac cell membrane excitability to reduce the risk of arrhythmias. It has no effect on serum potassium levels unlike the alternative drugs listed above.
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This question is part of the following fields:
- Fluids And Electrolytes
- Pharmacology
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Question 14
Incorrect
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Regarding penicillin antibiotics, which of the following statements is CORRECT:
Your Answer:
Correct Answer: Patients with a history of atopy are at higher risk of hypersensitivity reactions.
Explanation:Allergic reactions to penicillins occur in 1 – 10% of exposed individuals; anaphylactic reactions occur in fewer than 0.05% of treated patients. Patients with a history of atopic allergy are at higher risk of anaphylactic reactions to penicillins. Patients with a history of anaphylaxis, urticaria, or rash immediately after penicillin use should not receive a penicillin or other beta-lactam antibiotics; about 0.5 – 6.5 % of penicillin-sensitive patients will also be allergic to the cephalosporins.
Patients with a history of a more minor rash (i.e. non-confluent, non-pruritic rash restricted to a small area of the body) or delayed reaction (rash occurring more than 72 hours after penicillin administration), may not be truly allergic and may be considered for penicillin or beta-lactam treatment in severe infection (although possibility of allergy should be borne in mind). Other beta-lactam antibiotics (including cephalosporins) can be used in these patients.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 15
Incorrect
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Regarding meningococcal meningitis, which of the following statements is CORRECT:
Your Answer:
Correct Answer: Infection occurs most commonly below the age of 5 years.
Explanation:About half of meningococcal disease occurs in children aged less than five years, and babies are at the highest risk because their immune systems have not yet fully developed. There is a second, smaller increase in risk for older adolescents, mainly for social and behavioural reasons. Infection is most common in winter months. Antibiotics should be given as soon as the diagnosis is suspected (ideally cultures should be performed first but this should not delay treatment), and ceftriaxone/cefuroxime is the first line antibiotic. Only healthcare workers who have been directly exposed to large particle droplets/secretions from the respiratory tract of the index case should receive prophylaxis.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 16
Incorrect
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Which of the following is NOT a common side effect of amiodarone:
Your Answer:
Correct Answer: Blue/green teeth discolouration
Explanation:Common side effects of amiodarone include: Bradycardia, Nausea and vomiting, Thyroid disorders – hypothyroidism and hyperthyroidism, Persistent slate grey skin discoloration, Photosensitivity, Pulmonary toxicity (including pneumonitis and fibrosis), Hepatotoxicity, Corneal microdeposits (sometimes with night glare), Peripheral neuropathy and Sleep disorders.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 17
Incorrect
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A 30-year-old man suffers from an open fracture of his forearm. As a consequence of his injury, the nerve that innervates the pronator quadratus muscle was severed.
Which of the following statements regarding the pronator quadratus muscle is considered correct?Your Answer:
Correct Answer: Its deep fibres bind the radius and ulna together
Explanation:Pronator quadratus is a deep-seated, short, flat, and quadrilateral muscle with fibres running in a parallel direction.
It arises from the oblique ridge on the anterior surface of the distal fourth of the Ulna. It is inserted in lateral border and anterior surface of the distal fourth of the radius. It is innervated by the anterior interosseous nerve, a branch of the median nerve (C8-T1). It is vascularized by the anterior interosseous artery.
The action of the pronator quadratus muscle along with the pronator teres result in the pronation of the radioulnar joint. Contraction of this muscle pulls the distal end of the radius over the ulna, resulting in the pronation of the radioulnar joint
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 18
Incorrect
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A 24-year-old patient is suspected to have a possible acute hepatitis B infection and is currently under investigation.
Which of the following markers is considered the earliest indicator of acute infection in acute Hepatitis B?Your Answer:
Correct Answer: Hepatitis B surface Ag
Explanation:HBsAg is the serological hallmark of HBV infection. After an acute exposure to HBV, HBsAg appears in serum within 1 to 10 weeks. Persistence of this marker for more than 6 months implies chronic HBV infection.
Anti-HBs is known as a neutralizing antibody, and confers long-term immunity. In patients with acquired immunity through vaccination, anti-HBs is the only serological marker detected in serum.
HBcAg is an intracellular presence in infected hepatocyte, thus it is not identified in the serum. During acute infection, anti-HBc IgM and IgG emerges 1–2 weeks after the presence of HBsAg along with raised serum aminotransferase and symptoms. After 6 months of acute infection, anti-HBc IgM wears off. Anti-HBc IgG continues to detect in both patients with resolved HBV infection and chronic hepatitis B.
Hepatitis D virus, also known as the delta hepatitis virus, is a defective ssRNA virus that requires HBV for replication. The infection can occur in one of two clinical forms, co-infection or superinfection. In a co-infection, the patient is simultaneously infected with HBV and HDV. In a superinfection, an HDV infection develops in a patient with a chronic HBV infection.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 19
Incorrect
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Regarding chronic idiopathic thrombocytopaenic purpura (ITP), which of the following statements is INCORRECT:
Your Answer:
Correct Answer: ITP is classically associated with massive splenomegaly.
Explanation:Chronic ITP is a relatively common disorder. The highest incidence is in women aged 15 – 50 years. It is the most common cause of thrombocytopaenia without anaemia or neutropaenia. It is usually idiopathic but it may been seen in association with other conditions. Platelet autoantibodies (usually IgG) result in the premature removal of platelets from the circulation by macrophages of the reticuloendothelial system. In many causes the antibody is directed against the glycoprotein IIb/IIIa or Ib complex. The normal platelet lifespan of 10 days is reduced to a few hours. Total megakaryocyte mass and platelet turnover are increased to approximately five times normal. Despite the destruction of platelets by splenic macrophages, the spleen is normally not enlarged. In fact, an enlarged spleen should lead to a search for other possible causes for the thrombocytopenia.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 20
Incorrect
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A 65-year-old man comes for a visit at the clinic with complaints of abdominal pain. On inquiring about drug history, you find out that he has been taking around 8-10 paracetamol to help relieve the pain.
Out of the following, which one is believed to be the main mechanism of action for paracetamol?Your Answer:
Correct Answer: Selective inhibition of COX-3 receptors
Explanation:The FDA categorizes Paracetamol as an NSAID (nonsteroidal anti-inflammatory drug) as it is believed to selectively inhibit cyclo-oxygenase 3 (COX-3) receptors in the brain and spinal cord.
COX-3 is a unique variant of the more known COX-1 and COX-2. It is responsible for the production of prostaglandins in central areas, which sensitizes free nerve endings to the chemical mediators of pain. Therefore, by selectively inhibiting COX-3, paracetamol effectively reduces pain sensation by increasing the pain threshold.
Acetaminophen does not inhibit cyclooxygenase in peripheral tissues and, therefore, has no peripheral anti-inflammatory effects.
The antipyretic actions of acetaminophen are likely attributed to direct action on heat-regulating centres in the brain, resulting in peripheral vasodilation, sweating, and loss of body heat. -
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 21
Incorrect
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Which of the following movements does the iliacus muscle produce?
Your Answer:
Correct Answer: Flexion of the thigh at the hip joint
Explanation:The iliacus flexes the thigh at the hip joint when the trunk is stabilised. It flexes the trunk against gravity when the body is supine.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 22
Incorrect
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An injury to the brachial plexus can cause Erb's palsy. The following is expected to happen to a patient suffering from this condition, except for which one:
Your Answer:
Correct Answer: Weakness of medial rotation of the arm
Explanation:Erb’s palsy can be caused by a traumatic force downward on the upper arm and shoulder that damages the upper root of the brachial plexus.
The patient will lose shoulder abduction (deltoid, supraspinatus), shoulder external rotation (infraspinatus), and elbow flexion as a result of this condition (biceps, brachialis).
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 23
Incorrect
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You examine a resuscitated patient who has been diagnosed with ventricular tachycardia. The patient's hemodynamics are normal. You intended to prescribe amiodarone to him, but you can't because he has a contraindication.
In these circumstances, which of the following is a contraindication to using amiodarone?Your Answer:
Correct Answer: Sinus node disease
Explanation:Amiodarone is an anti-arrhythmic medication that can be used to treat both ventricular and atrial arrhythmias.
The use of amiodarone is contraindicated in the following situations:
Conduction disturbances that are severe (unless pacemaker fitted)
Sinus node disease is a condition that affects the lymph nodes in (unless pacemaker fitted)
Sensitivity to iodine
Blockage of the Sino-atrial heart valve (except in cardiac arrest)
Bradycardia in the sinuses (except in cardiac arrest)
Thyroid disorders -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 24
Incorrect
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A patient sustains an injury to the proximal median nerve after falling through a glass door. Which of the following muscles would you not expect to be affected:
Your Answer:
Correct Answer: Flexor carpi ulnaris
Explanation:All of the muscles in the anterior forearm are innervated by the median nerve, except for the flexor carpi ulnaris and the medial half of the flexor digitorum profundus which are innervated by the ulnar nerve.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 25
Incorrect
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What proportion of peripheral blood leukocytes are monocytes?
Your Answer:
Correct Answer: 5 - 10%
Explanation:Monocytes account for around 5 to 10% of peripheral white cells. Monocytes in peripheral blood are generally bigger than other leukocytes and feature a large central oval or indented nucleus with clumped chromatin. The abundant cytoplasm staining blue and containing numerous fine vacuoles gives the appearance of ground glass. Cytoplasmic granules are another type of granule.
Monocytes evolve from the granulocyte-macrophage progenitor to become monoblasts, promonocytes, monocytes, and tissue macrophages (in increasing order of maturity). Monocytes only stay in the bone marrow for a short time before exiting to circulate in the bloodstream for 20-40 hours before becoming macrophages.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 26
Incorrect
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Antidiuretic hormone (ADH) levels are found to be increased in a young lady with unexplained hyponatraemia.
In a healthy patient under normal circumstances, in which of the following conditions would ADH not be released?Your Answer:
Correct Answer: Increased alcohol intake
Explanation:Antidiuretic hormone (ADH) is produced in the hypothalamus’s supraoptic nucleus and then released into the blood via axonal projections from the hypothalamus to the posterior pituitary.
It is carried down axonal extensions from the hypothalamus (the neurohypophysial capillaries) to the posterior pituitary, where it is kept until it is released, after being synthesized in the hypothalamus.
The secretion of ADH from the posterior pituitary is regulated by numerous mechanisms:
Increased plasma osmolality: Osmoreceptors in the hypothalamus detect an increase in osmolality and trigger ADH release.Hypovolaemia causes a drop in atrial pressure, which stretch receptors in the atrial walls and big veins detect (cardiopulmonary baroreceptors). ADH release is generally inhibited by atrial receptor firing, but when the atrial receptors are stretched, the firing reduces and ADH release is promoted.
Hypotension causes baroreceptor firing to diminish, resulting in increased sympathetic activity and ADH release.
An increase in angiotensin II stimulates angiotensin II receptors in the hypothalamus, causing ADH production to increase.Nicotine, Sleep, Fright, and Exercise are some of the other elements that might cause ADH to be released.
Alcohol (which partly explains the diuretic impact of alcohol) and elevated levels of ANP/BNP limit ADH release. -
This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 27
Incorrect
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Glucagon may be used as an antidote for overdose with which of the following:
Your Answer:
Correct 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 28
Incorrect
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Eosinophils comprise what percentage of circulating white cells:
Your Answer:
Correct Answer: 1 - 3%
Explanation:Eosinophils comprise 1 – 3% of circulating white cells. Eosinophils are similar to neutrophils, except that the cytoplasmic granules are coarser and more deeply red staining, and there are rarely more than three nuclear lobes. They are less motile, but longer lived. They enter inflammatory exudates and have a special role in allergic responses, defence against parasites and removal of fibrin formed during inflammation. Thus they play a role in local immunity and tissue repair.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 29
Incorrect
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Regarding the lacrimal apparatus, which of the following statements is CORRECT:
Your Answer:
Correct Answer: Lacrimal fluid is drained from the eyeball through the lacrimal punctum.
Explanation:Lacrimal fluid is drained from the eyeball through the lacrimal punctum.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 30
Incorrect
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A 57-year-old male presents to the orthopaedic clinic complaining of pain and swelling in the left knee joint. On examination, the left knee is swollen, tender and erythematous. The patient is booked for joint aspiration, and a diagnosis of pseudogout is made following the aspiration.
Which types of crystals would be seen in the joint aspirate to lead to this diagnosis?Your Answer:
Correct Answer: Positively birefringent brick-shaped crystals
Explanation:Gout and pseudogout are both characterised by crystal deposition in the affected joints. The deposition of urate crystals causes gout, while calcium pyrophosphate crystals cause pseudogout. The crystals can be distinguished microscopically because urate crystals are negatively birefringent needle-shaped crystals, whilst calcium pyrophosphate crystals are positively birefringent brick-shaped crystals.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 31
Incorrect
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A 36-year-old man presented to the emergency room with a two-week history of shortness of breath, fevers, and malaise. A chest X-ray was ordered and the results confirmed the diagnosis of a right middle lobe pneumonia.
Which of the following structures of the heart lies closest to the consolidation?Your Answer:
Correct Answer: Right atrium
Explanation:In its typical anatomical orientation, the heart has 5 surfaces formed by different internal divisions of the heart:
Anterior (or sternocostal) – Right ventricle
Posterior (or base) – Left atrium
Inferior (or diaphragmatic) – Left and right ventricles
Right pulmonary – Right atrium
Left pulmonary – Left ventricleThe silhouette sign of Felson is with respect to the right middle lobe. The right heart border should have a distinct appearance due to the right atrium abutting aerated right middle lobe. The consolidation in the right middle lobe has resulted in loss of this silhouette.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 32
Incorrect
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In the extrinsic pathway of the coagulation cascade, the tenase complex is:
Your Answer:
Correct Answer: Factor VIIa-tissue factor complex
Explanation:The extrinsic pathway for initiating the formation of prothrombin activator begins with a traumatized vascular wall or traumatized extravascular tissues that come in contact with the blood. Exposed and activated by vascular injury, with plasma factor VII. The extrinsic tenase complex, factor VIIa-tissue factor complex, activates factor X to factor Xa.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 33
Incorrect
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Which of the following is NOT a typical cerebellar sign:
Your Answer:
Correct Answer: Hypertonia
Explanation:Hypotonia means decreased muscle tone. It can be a condition on its own, called benign congenital hypotonia, or it can be indicative of another problem where there is progressive loss of muscle tone, such as muscular dystrophy or cerebral palsy. It is usually detected during infancy. Hypotonia is characteristic of cerebellar dysfunction.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 34
Incorrect
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An analytical study is conducted to compare the risk of stroke between Ticagrelor therapy and Warfarin therapy among patients with atrial fibrillation. The following is obtained from the study:
No. of patients who took Ticagrelor: 300
No. of patients who took Ticagrelor and suffered a stroke: 30
No. of patients who took Warfarin: 500
No. of patients who took Warfarin and suffered a stroke: 20
Compute for the absolute risk reduction of a stroke, with Warfarin as the standard of treatment.Your Answer:
Correct Answer: -0.06
Explanation:Absolute risk reduction (ARR) is computed as the difference between the absolute risk in the control group (ARC) and the absolute risk in the treatment group (ART).
Since Warfarin is the standard of treatment, Warfarin is considered as the control group.
ARR = ARC-ART
ARR = (20/500) – (30/300)
ARR = -0.06This means that there is increased risk of stroke in the treatment group, which is the Ticagrelor group.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 35
Incorrect
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A 60-year-old patient had a sudden onset of palpitations and shortness of breath. He had a history of poorly controlled hypertension and ischemic heart disease. His ECG also shows atrial fibrillation. Based on the patient’s condition, which pharmacologic cardioversion would be best to use?
Your Answer:
Correct Answer: Amiodarone
Explanation:Chemical cardioversion, or pharmacologic cardioversion, is the treatment of abnormal heart rhythms using drugs.
Flecainide and propafenone are examples of drugs used as chemical cardioverters.
However, given the situation of the patient, these drugs are contraindicated for his ischaemic heart disease. Amiodarone is also an antiarrhythmic drug and is the best choice for this situation.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 36
Incorrect
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Which of the following statements is correct with regards to heparin-induced thrombocytopaenia (HIT)?
Your Answer:
Correct Answer: HIT typically develops 5-10 days after starting heparin.
Explanation:Heparin-induced thrombocytopenia (HIT) is a prothrombotic disorder caused by antibodies that recognize complexes of platelet factor 4 (PF4) and heparin. HIT is frequently considered in the differential diagnosis of thrombocytopenia occurring in patients on heparin therapy. HIT is a challenging diagnosis because of routine heparin use in hospitalized patients, the common occurrence of thrombocytopenia. The process of heparin dependent IgG antibodies binding to heparin/platelet factor 4 complexes activates platelets and produces a hypercoagulable state. This syndrome typically develops 5-10 days (range 4-15 days) after heparin is commenced. It can occur with unfractionated heparin, low molecular weight heparin, or, rarely, fondaparinux. The diagnosis of HIT requires the combination of a compatible clinical picture and laboratory confirmation of the presence of heparin dependent platelet activating HIT antibodies. Discontinuation of heparin alone or initiation of a vitamin K antagonist alone like warfarin, is not sufficient to stop the development of thrombosis in patients with acute HIT. If there is moderate clinical suspicion for HIT, all sources of heparin must be discontinued and there must be consideration of anticoagulant treatment with a non-heparin drug.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 37
Incorrect
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Which of the following is NOT a typical side effect of opioid analgesics:
Your Answer:
Correct Answer: Diarrhoea
Explanation:All opioids have the potential to cause:
Gastrointestinal effects – Nausea, vomiting, constipation, difficulty with micturition (urinary retention), biliary spasm
Central nervous system effects – Sedation, euphoria, respiratory depression, miosis
Cardiovascular effects – Peripheral vasodilation, postural hypotension
Dependence and tolerance -
This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 38
Incorrect
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Which lobe of the prostate gland is most commonly affected in prostatic carcinoma?
Your Answer:
Correct Answer: Posterior
Explanation:The periurethral portion of the prostate gland increases in size during puberty and after the age of 55 years due to the growth of non-malignant cells in the transition zone of the prostate that surrounds the urethra. Most cancers develop in the posterior lobe, and cancers in this location may be palpated during a digital rectal examination (DRE).
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This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 39
Incorrect
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After reviewing a child with respiratory distress who presented to the clinic, you make a diagnosis of bronchiolitis.
What is the most common causative organism?
Your Answer:
Correct Answer: Respiratory syncitial virus
Explanation:Bronchiolitis is a common respiratory infection that occurs in infancy between the ages of 3-6 months and in the winter months. It is most commonly caused by the respiratory syncytial virus (70% of cases)
Although it can also be caused by parainfluenza virus, adenovirus, coronavirus, rhinovirus, and influenza virus, these are not the most common causes
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 40
Incorrect
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Which of the following causes type 1 diabetes mellitus?
Your Answer:
Correct Answer: Autoimmune destruction of beta-cells results in insulin deficiency
Explanation:Type 1 diabetes mellitus results from autoimmune destruction of the insulin-producing beta cells in the islets of Langerhans. This process occurs in genetically susceptible subjects, is probably triggered by one or more environmental agents, and usually progresses over many months or years during which the subject is asymptomatic and euglycemic.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 41
Incorrect
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Which of the following immunoglobulin molecules is the most abundant in secretions (such as saliva and breast milk):
Your Answer:
Correct Answer: IgA
Explanation:IgA is the predominant antibody class in secretions and tremendous quantities are secreted into various body spaces and onto mucosal surfaces (the gut lumen, the pharynx and sinuses, the larger airways, although not the alveoli).
Because of its size, the majority of IgM is found in the circulation.Along with IgM, IgD is predominant among the surface receptors of mature B cells, where it plays a key role in B cells activation.
IgE has the lowest concentration in normal human serum. It plays a prominent role in immune responses to helminth parasites, and in allergic reactions.
IgG is the most abundant immunoglobulin and constitutes 75 percent of serum immunoglobulin in an adult human -
This question is part of the following fields:
- Immune Responses
- Pathology
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Question 42
Incorrect
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C3 deficiency leads to particular susceptibility of infection with which of the following:
Your Answer:
Correct Answer: Encapsulated bacteria
Explanation:Macrophages and neutrophils have C3b receptors and they phagocytose C3b-coated cells. C3 deficiency thus leads to increased susceptibility of infection with encapsulated organisms (e.g. S. pneumoniae, H. influenzae).The early stages of the complement cascade leading to coating of the cells with C3b can occur by two different pathways:The classical pathway usually activated by IgG or IgM coating of cellsThe alternative pathway which is more rapid and activated by IgA, endotoxin and other factors
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 43
Incorrect
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You suspected typhoid disease in a patient who had recently returned from South America and presented to the emergency department with fever, constipation, and a rose spot rash. Which of the following antibiotics will be administered to this patient?
Your Answer:
Correct Answer: Cefotaxime
Explanation:Typhoid fever, often known as enteric fever, is a potentially fatal multi-systemic sickness caused predominantly by Salmonella enterica serotype typhi and, to a lesser extent, paratyphi A, B, and C.
Cefotaxime is the first-line treatment for typhoid fever (or ceftriaxone). In cases of mild or moderate sickness caused by multiresistant pathogens, azithromycin is an option. If the bacterium is sensitive, ciprofloxacin is an option.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 44
Incorrect
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A patient presents with a gastrointestinal infection. Which of the following microbes attaches to gut mucosa via a specialised sucking disc:
Your Answer:
Correct Answer: Giardia lamblia
Explanation:Giardia lambliainfection occurs through the ingestion of dormant microbial cysts in contaminated water, food or via faceo-oral transmission via poor hygiene.
Following ingestion of the cysts, the trophozoite emerges to an active state of feeding and motility. After the feeding stage they undergo asexual replication through longitudinal binary fission.
They attach to the intestinal wall via a specialised sucking disc. The mechanism for diarrhoea in giardiasis remains unknown but could possibly be due to direct cytotoxicity.
Giardial trophozoites and cysts pass through the digestive system in the faeces and are excreted. While the trophozoites may be found in the faeces, only the cysts are adapted for long-term survival outside the host. -
This question is part of the following fields:
- Microbiology
- Principles
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Question 45
Incorrect
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A 31-year-old man with sickle-cell disease receives a blood transfusion for symptomatic anaemia. He presents to the Emergency Department three weeks later with a rash, fever, and diarrhoea. He has pancytopenia and abnormal liver function results on blood tests.
Which of the transfusion reactions is most likely to have happened?Your Answer:
Correct Answer: Graft-vs-host disease
Explanation:Blood transfusion can be a life-saving treatment with significant clinical benefits, but it also comes with a number of risks and potential complications, including:
Immunological side effects
Errors in administration (episodes of ‘wrong blood’)
Viruses and Infections (bacterial, viral, possibly prion)
ImmunodilutionA culture of better safety procedures as well as steps to reduce the use of transfusion has emerged as a result of growing awareness of avoidable risk and improved reporting systems. Transfusion errors, on the other hand, continue to occur, and some serious adverse reactions go unreported.
Transfusion-associated graft-vs-host disease (TA-GVHD) is a rare blood transfusion complication that causes fever, rash, and diarrhoea 1-4 weeks after the transfusion. Pancytopenia and liver function abnormalities are common laboratory findings.
TA-GVHD, unlike GVHD following allogeneic marrow transplantation, causes profound marrow aplasia with a mortality rate of >90%. Survival is uncommon, with death occurring within 1-3 weeks of the onset of symptoms.
Because of immunodeficiency, severe immunosuppression, or shared HLA antigens, viable T lymphocytes in blood components are transfused, engraft, and react against the recipient’s tissues, and the recipient is unable to reject the donor lymphocytes.
The following is a list of the most common transfusion reactions and complications:1) Reaction to a febrile transfusion
The temperature rises by one degree from the baseline. Chills and malaise are also possible symptoms.
The most common response (1 in 8 transfusions).
Cytokines from leukocytes in transfused red cell or platelet components are usually to blame.
Only supportive. The use of paracetamol is beneficial.2) Acute haemolytic reaction is a type of haemolytic reaction that occurs when the
Fever, chills, pain at the transfusion site, nausea, vomiting, and dark urine are all symptoms of a transfusion reaction.
Early on, many people report a sense of ‘impending doom.’
The most serious reaction. ABO incompatibility is frequently caused by a clerical error.
STOP THE TRANSFUSION OF INFORMATION. IV fluids should be given. It’s possible that diuretics will be required.3) Haemolytic reaction that is delayed
It usually happens 4 to 8 days after a blood transfusion.
Fever, anaemia, jaundice, and haemoglobinuria are all symptoms that the patient has.
Positive Coombs test for direct antiglobulin.
Because of the low titre antibody, it is difficult to detect in a cross-match, and it is unable to cause lysis at the time of transfusion.
The majority of delayed haemolytic reactions are harmless and do not require treatment.
Anaemia and renal function should be monitored and treated as needed.4) Reaction to allergens
Foreign plasma proteins are usually to blame, but anti-IgA could also be to blame.
Urticaria, pruritus, and hives are typical allergic reactions. It’s possible that it’s linked to laryngeal oedema or bronchospasm.
Anaphylaxis is a rare occurrence.
Antihistamines can be used to treat allergic reactions symptomatically. It is not necessary to stop transfusions.
If the patient develops anaphylaxis, the transfusion should be stopped and the patient should be given adrenaline and treated according to the ALS protocol.5) TRALI (Transfusion Related Acute Lung Injury)
Within 6 hours of transfusion, there was a sudden onset of non-cardiogenic pulmonary oedema.
It’s linked to the presence of antibodies to recipient leukocyte antigens in the donor blood.
The most common cause of death from transfusion reactions is this.
STOP THE TRANSFUSION OF INFORMATION. Oxygen should be given to the patient. Around 75% of patients will require aggressive respiratory support.
The use of diuretics should be avoided.6) TACO (Transfusion Associated Circulatory Overload)
Acute or worsening respiratory distress within 6 hours of a large blood transfusion. Fluid overload and pulmonary and peripheral oedema can be seen. Rapid blood pressure rises are common. BNP is usually 1.5 times higher than it was before the transfusion. It is most common in the elderly and those who have chronic anaemia.Blood transfusions should be given slowly, over the course of 3-4 hours.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 46
Incorrect
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A young man develops an infection spread via aerosol transmission.
Which of these organisms is commonly spread by aerosol transmission?Your Answer:
Correct Answer: Measles virus
Explanation:Aerosols are airborne particles less than 5 µm in size, containing infective organisms that usually cause infection of the upper or lower respiratory tract.
Examples of organisms commonly spread by aerosol transmission are:
Measles virus
Varicella zoster virus
Mycobacterium tuberculosisThe following table summarises the various routes of transmission with example organisms:
Route of transmission
Example organisms
Aerosol (airborne particle < 5 µm)
Mycobacterium tuberculosis
Varicella zoster virus
Measles virusHepatitis A and Rotavirus are spread by the faeco-oral route.
Neisseria gonorrhoea is spread by sexual route.
Staphylococcus aureus is spread by direct contact.
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 47
Incorrect
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Question 48
Incorrect
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You examine a 34-year-old lady with symptoms that are consistent with acute sinusitis. You're thinking about giving her doxycycline for treatment.
What is doxycycline's mechanism of action?Your Answer:
Correct Answer: Inhibition of protein synthesis
Explanation:Doxycycline and other tetracycline antibiotics attach to the 30S subunit of the bacterial ribosome, preventing aminoacyl-tRNA binding and so protein synthesis beginning.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 49
Incorrect
-
All of the following are physiological effects of thyroid hormones except:
Your Answer:
Correct Answer: Increased glycogenesis
Explanation:Thyroid hormones have multiple physiological effects on the body. These include:
1. Heat production (thermogenesis)
2. Increased basal metabolic rate
3. Metabolic effects:
(a) Increase in protein turnover (both synthesis and degradation are increased, although overall effect is catabolic)
(b) Increase in lipolysis
(c)Increase in glycogenolysis and gluconeogenesis
4. Enhanced catecholamine effect – Increase in heart rate, stroke volume and thus cardiac output
5. Important role in growth and development -
This question is part of the following fields:
- Endocrine
- Physiology
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Question 50
Incorrect
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Intracellular [Ca2+] rise in cardiac excitation-contraction coupling is mainly as a result of:
Your Answer:
Correct Answer: Ca 2+ release from sarcoplasmic reticulum
Explanation:Although Ca2+entry during the action potential (AP) is essential for contraction, it only accounts for about 25% of the rise in intracellular Ca2+. The rest is released from Ca2+stores in the sarcoplasmic reticulum (SR). APs travel down invaginations of the sarcolemma called T-tubules, which are close to, but do not touch, the terminal cisternae of the SR. 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. The amount of Ca2+released is dependent on how much is stored, and on the size of the initial Ca2+influx during the AP.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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SESSION STATS - PERFORMANCE PER SPECIALTY
