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  • Question 1 - A 42-year-old woman presents with face swelling prominently affecting her upper lip and...

    Correct

    • A 42-year-old woman presents with face swelling prominently affecting her upper lip and hands. She has previously been diagnosed with hereditary angioedema.

      Which of these is the most appropriate management option for this acute attack?

      Your Answer: Fresh frozen plasma

      Explanation:

      Hereditary angioedema is inherited as an autosomal dominant disorder and is caused by deficiency of C1 esterase inhibitor, a protein that forms part of the complement system.

      Attacks can be precipitated by stress and minor surgical procedures. Clinical features of hereditary angioedema include oedema of the skin and mucous membranes commonly affecting the face, tongue and extremities.

      Angioedema and anaphylaxis due to a deficiency of C1 esterase inhibitor are resistant to adrenaline, steroids and antihistamines. Treatment is with fresh frozen plasma or C1 esterase inhibitor concentrate, which contains C1 esterase inhibitor.

      Short-term prophylaxis for events that may precipitate angioedema attack is achieved with C1 esterase inhibitor or fresh frozen plasma infusions before the event while long-term prophylaxis can be achieved with antifibrinolytic drugs (tranexamic acid) or androgenic steroids.

    • This question is part of the following fields:

      • Pharmacology
      • Respiratory Pharmacology
      15.4
      Seconds
  • Question 2 - A 38-year-old woman is investigated for Addison's disease. She had low blood pressure,...

    Correct

    • A 38-year-old woman is investigated for Addison's disease. She had low blood pressure, weakness, weight loss, and skin discoloration. An adrenocorticotropic hormone (ACTH) stimulation test is scheduled as part of her treatment.

      Which of the following statements about ACTH is correct?

      Your Answer: It is released in response to the release of CRH

      Explanation:

      The anterior pituitary gland produces and secretes a peptide hormone called adrenocorticotropic hormone (ACTH) (adenohypophysis). It is secreted in response to the hypothalamus’s secretion of the hormone corticotropin-releasing hormone (CRH).

      ACTH promotes cortisol secretion via binding to cell surface ACTH receptors in the zona fasciculata of the adrenal cortex.

      ACTH also promotes the production of beta-endorphin, which is a precursor to melanocyte-releasing hormone (MRH).

    • This question is part of the following fields:

      • Endocrine Physiology
      • Physiology
      28.1
      Seconds
  • Question 3 - A 7-year-old presented to a GP with a history of headache, neck stiffness...

    Correct

    • A 7-year-old presented to a GP with a history of headache, neck stiffness and photophobia. On examination, HR is 122, BP is 87/42, RR is 28, SaO 2 is 95%, temperature is 39.4 o C. There is a recent non-blanching rash on legs and arms. The GP administered a dose of antibiotics before transferring child to the Emergency Department.

      Which of these is the most appropriate antibiotic to administer in this scenario from the choices available?

      Your Answer: Give IM benzylpenicillin 600 mg

      Explanation:

      Meningococcal septicaemia should be suspected in a child with a non-blanching rash especially in the presence of:
      An ill-looking child
      Neck stiffness
      Lesions larger than 2 mm in diameter (purpura)
      Capillary refill time of>3 seconds

      The index child is very sick and shows signs of septic shock. In the prehospital setting, a single dose of benzylpenicillin should be given immediately. The correct dose for this childs age is IM benzylpenicillin 600 mg.

      The recommended doses of benzylpenicillin according to age are:
      Infants <1 year of age: IM or IV benzylpenicillin 300 mg
      Children 1 to 9 years of age: IM or IV benzylpenicillin 600mg
      Children and adults 10 years or older: IM or IV benzylpenicillin 1.2g

    • This question is part of the following fields:

      • Infections
      • Pharmacology
      31.1
      Seconds
  • Question 4 - Which of the following is a well recognised adverse effect of prochlorperazine: ...

    Correct

    • Which of the following is a well recognised adverse effect of prochlorperazine:

      Your Answer: Acute dystonic reaction

      Explanation:

      Adverse actions include anticholinergic effects such as drowsiness, dry mouth, and blurred vision, extrapyramidal effects, and postural hypotension. Phenothiazines can all induce acute dystonic reactions such as facial and skeletal muscle spasms and oculogyric crises; children (especially girls, young women, and those under 10 kg) are particularly susceptible.

    • This question is part of the following fields:

      • Central Nervous System
      • Pharmacology
      10.6
      Seconds
  • Question 5 - The least likely feature expected to be seen in a lesion of the...

    Correct

    • The least likely feature expected to be seen in a lesion of the frontal lobe is which of the following?

      Your Answer: Loss of two-point discrimination

      Explanation:

      Lesions in different areas give rise to different symptoms.
      Lesions of the parietal lobe give rise to loss of two-point discrimination.
      Lesions to Broca’s area give rise to expressive dysphasia results from damage
      Lesions to the primary motor cortex give rise to contralateral weakness of the face and arm.
      Lesions to the prefrontal cortex give rise to personality change.
      Lesions to the frontal eye field give rise to conjugate eye deviation towards side of lesion.

    • This question is part of the following fields:

      • Anatomy
      • Central Nervous System
      19.2
      Seconds
  • Question 6 - A 66-year-old patient attends the Emergency Department with chest pain. His ECG and...

    Correct

    • A 66-year-old patient attends the Emergency Department with chest pain. His ECG and troponin are suggestive of a new myocardial infarction. You have explained the condition and the prognosis. He asks you about how the damaged area of his heart will heal following this.
      Which answer best describes the process of myocardial healing following myocardial infarction? Select ONE answer only.

      Your Answer: The damaged myocardium will form non-contractile scar tissue

      Explanation:

      Myocardial cells are unable to regenerate, they are unable to divide in response to tissue injury. The remain permanently in G0 and cannot progress to G1. If a segment of muscle dies, for example in myocardial infarction, this tissue will be replaced by scar tissue if the patient recovers. This scar tissue is non-contractile and therefore the remaining myocardium must work harder to maintain cardiac output. As a consequence the remaining undamaged myocardium undergoes compensatory hypertrophy without cell division.

    • This question is part of the following fields:

      • General Pathology
      • Pathology
      38.4
      Seconds
  • Question 7 - Regarding control of hospital acquired infection (HAI), which of the following statements is...

    Correct

    • Regarding control of hospital acquired infection (HAI), which of the following statements is CORRECT:

      Your Answer: Chlorhexidine is an anti-staphylococcal agent.

      Explanation:

      Chlorhexidine is an anti-staphylococcal agent. Cleaning is the removal of foreign material from areas or objects to a point at which they are visually free from debris.  Disinfection is the reduction in the number of infectious particles. Isopropyl alcohol is not effective against C. difficile spores. Autoclaving is a method of sterilisation.

    • This question is part of the following fields:

      • Microbiology
      • Principles
      50
      Seconds
  • Question 8 - Which of these cell types in the stomach releases pepsinogen? ...

    Correct

    • Which of these cell types in the stomach releases pepsinogen?

      Your Answer: Chief cells

      Explanation:

      The gastric chief cells in the stomach wall releases pepsinogen. Pepsinogen is a proenzyme. It mixes with hydrochloric acid in the stomach and is converted to pepsin. Pepsin breaks down proteins into peptides aiding protein digestion.

    • This question is part of the following fields:

      • Gastrointestinal Physiology
      • Physiology
      6.9
      Seconds
  • Question 9 - One of your patients is undergoing resuscitation and is in septic shock. The...

    Correct

    • One of your patients is undergoing resuscitation and is in septic shock. The intensive care outreach team arrives to assess them and determines that a dobutamine infusion should be started.

      Which of the following receptors does dobutamine primarily affect?

      Your Answer: Beta-1 receptors

      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.

      A summary of the mechanism and effects of different inotropic agents is shown below:
      Inotrope
      Mechanism
      Effects
      Adrenaline (epinephrine)
      Beta-1 and -2 agonist at increasing doses;
      Alpha-agonist at high doses
      Increased cardiac output;
      Vasoconstriction at higher doses
      Noradrenaline (norepinephrine)
      Mainly alpha-agonist;
      Beta-1 and -2 agonist at increasing doses
      Vasoconstriction;
      Some increased cardiac output
      Dopamine
      Dopamine agonist at low doses;
      Beta-1 and -2 agonist at increasing doses;
      Alpha-agonist at high doses
      Increased cardiac output;
      Vasoconstriction at higher doses
      Dobutamine
      Mainly beta-1 agonist
      Increased cardiac output

    • This question is part of the following fields:

      • Cardiovascular Pharmacology
      • Pharmacology
      20
      Seconds
  • Question 10 - A 40-year-old woman presents with retrosternal central chest pain that she has been...

    Correct

    • A 40-year-old woman presents with retrosternal central chest pain that she has been complaining about for the past two days. Upon deep inspiration and while lying flat, the pain worsens but relieved by sitting forwards. The pain radiates to both of her shoulders. The result of her ECG shows widespread concave ST-elevation and PR depression. A diagnosis of pericarditis is suspected.

      Which of the following nerves is responsible for the pattern of her pain?

      Your Answer: Phrenic nerve

      Explanation:

      Pericarditis is inflammation of the pericardial sac and is the most common pathologic process involving the pericardium. Frequently, pericardial inflammation can be accompanied by increased fluid accumulation within the pericardial sac forming a pericardial effusion, which may be serous, hemorrhagic or purulent depending on aetiology.

      The classic presentation is with chest pain that is central, severe, pleuritic (worse on deep inspiration) and positional (improved by sitting up and leaning forward). The pain may also be radiating and may involve the ridges of the trapezius muscle if the phrenic nerve is inflamed as it traverses the pericardium.

    • This question is part of the following fields:

      • Anatomy
      • Thorax
      29.7
      Seconds
  • Question 11 - A 70-year-old woman presents with exacerbation of her chronic obstructive pulmonary disease (COPD),...

    Incorrect

    • A 70-year-old woman presents with exacerbation of her chronic obstructive pulmonary disease (COPD), increased cough, wheeze and chest tightness. On examination, she is tachypnoeic and oxygen saturation is 86%. You plan to administer supplemental oxygen.

      Which oxygen delivery system is most appropriate to use initially?

      Your Answer: Nasal cannulae

      Correct Answer: Venturi mask

      Explanation:

      In life-threatening emergencies, oxygen should be started immediately otherwise, it should be prescribed like any other drug. The prescription should include a target saturation range.

      Until blood gases can be measured, initial oxygen should be administered using a controlled concentration of 24% or 28%.
      The ideal mask is a Venturi mask.

      The other mask are not ideal for initial use

    • This question is part of the following fields:

      • Pharmacology
      • Respiratory Pharmacology
      190.6
      Seconds
  • Question 12 - Clostridium difficile primarily causes which of the following infectious diseases: ...

    Correct

    • Clostridium difficile primarily causes which of the following infectious diseases:

      Your Answer: Pseudomembranous colitis

      Explanation:

      Clostridium difficile causes pseudomembranous colitis, an acute inflammatory diarrhoeal disease and an important cause of morbidity and mortality in hospitals. Gas gangrene is primarily caused by Clostridium perfringens. Tetanus is caused by Clostridium tetani. Toxic shock syndrome may be caused by Staphylococcus aureus or Streptococcus pyogenes. Necrotising fasciitis is most commonly caused by Streptococcus pyogenes but has a multitude of causes.

    • This question is part of the following fields:

      • Microbiology
      • Pathogens
      27.5
      Seconds
  • Question 13 - A 68-year-old patient shows Low calcium levels and is on dialysis for chronic...

    Incorrect

    • A 68-year-old patient shows Low calcium levels and is on dialysis for chronic kidney disease.

      What percentage of total serum calcium is in the form of free or ionised Ca 2+?

      Your Answer: 90%

      Correct Answer: 50%

      Explanation:

      Approximately half of total serum calcium is in the free or ionised Ca2+ state, 40% is attached to plasma proteins (mostly albumin), and the remaining 10% is in complexes with organic ions like citrate and phosphate. The ionized form is the only one that works.

    • This question is part of the following fields:

      • Endocrine Physiology
      • Physiology
      12.9
      Seconds
  • Question 14 - Angiotensin II acts to cause all but which one of the following effects:...

    Incorrect

    • Angiotensin II acts to cause all but which one of the following effects:

      Your Answer: Stimulate the sensation of thirst

      Correct Answer: Inhibit release of ADH from the posterior pituitary gland

      Explanation:

      Angiotensin II acts to:
      Stimulate release of aldosterone from the zona glomerulosa of the adrenal cortex (which in turn acts to increase sodium reabsorption)
      Cause systemic vasoconstriction
      Cause vasoconstriction of the renal arterioles (predominant efferent effect thus intraglomerular pressure is stable or increased, thereby tending to maintain or even raise the GFR)
      Directly increase Na+reabsorption from the proximal tubule (by activating Na+/H+antiporters)
      Stimulate synthesis and release of ADH from the hypothalamus and posterior pituitary respectively
      Stimulate the sensation of thirst
      Potentiate sympathetic activity (positive feedback)
      Inhibit renin production by granular cells (negative feedback)

    • This question is part of the following fields:

      • Physiology
      • Renal
      24.5
      Seconds
  • Question 15 - Identify the type of graph described below:

    This graph is a scatter plot of...

    Correct

    • Identify the type of graph described below:

      This graph is a scatter plot of the effect estimates from individual studies against some measure of each study's size or precision.

      Your Answer: Funnel plot

      Explanation:

      A funnel plot is a scatter plot of the effect estimates from individual studies against some measure of each study’s size or precision. The standard error of the effect estimate is often chosen as the measure of study size and plotted on the vertical axis with a reversed scale that places the larger, most powerful studies towards the top. The effect estimates from smaller studies should scatter more widely at the bottom, with the spread narrowing among larger studies. In the absence of bias and between study heterogeneity, the scatter will be due to sampling variation alone and the plot will resemble a symmetrical inverted funnel. A triangle centred on a fixed effect summary estimate and extending 1.96 standard errors either side will include about 95% of studies if no bias is present and the fixed effect assumption (that the true treatment effect is the same in each study) is valid.

    • This question is part of the following fields:

      • Evidence Based Medicine
      18
      Seconds
  • Question 16 - Due to severe palpitations, a 28-year-old woman is transported to the Emergency Department...

    Correct

    • Due to severe palpitations, a 28-year-old woman is transported to the Emergency Department by ambulance. Her heart rate is 180 beats per minute, and the rhythm strip shows supraventricular tachycardia. You intend to give adenosine.

      Which of the following is NOT a contraindication for adenosine use?

      Your Answer: History of heart transplant

      Explanation:

      The purine nucleoside adenosine is used to diagnose and treat paroxysmal supraventricular tachycardia. Adenosine works by stimulating A1-adenosine receptors and opening potassium channels that are sensitive to acetylcholine. This causes the atrioventricular (AV) node’s cell membrane to become hyperpolarized, slowing conduction by inhibiting calcium channels.

      Patients who have had a heart transplant are extremely sensitive to the effects of adenosine and should start with a lower dose of 3 mg, then 6 mg, and finally 12 mg. Dipyridamole potentiates the effects of adenosine, so it should be used with caution in patients who are taking it.

      The use of adenosine is contraindicated in the following situations:
      Asthma
      COPD (chronic obstructive pulmonary disease)
      Decompensated heart failure 
      Long QT syndrome
      AV block in the second or third degree
      Sinusitis is a condition in which the sinuses become (unless pacemaker fitted)
      Hypotension that is severe

      It has a half-life of less than 10 seconds and acts quickly within that time frame. The actions last between 10 and 20 seconds.
      Because of the short half-life of the drug, any side effects are usually only temporary. These are some of them:
      a feeling of impending doom
      Flushing of the face
      Dyspnoea
      Uncomfortable chest
      Tastes metallic

    • This question is part of the following fields:

      • Cardiovascular Pharmacology
      • Pharmacology
      21.6
      Seconds
  • Question 17 - Regarding carbon dioxide transport in the blood, which of the following statements is...

    Correct

    • Regarding carbon dioxide transport in the blood, which of the following statements is CORRECT:

      Your Answer: Deoxygenated haemoglobin acts as a buffer for H+ ions.

      Explanation:

      CO2generated in the tissues and water combine to form carbonic acid which readily dissociates to form HCO3-and H+. The first part of this reaction is very slow in plasma, but is accelerated dramatically by the enzyme carbonic anhydrase present in red blood cells. Bicarbonate is therefore formed preferentially in red cells, from which it freely diffuses down its concentration gradient into plasma where it is transported to the lungs. The red cell membrane is impermeable to H+ions which remain in the cell. To maintain electroneutrality, Cl-ions diffuse into the cell to replace HCO3-, an effect known as the chloride shift. Deoxygenated haemoglobin acts as a buffer for H+, allowing the reaction to continue.

    • This question is part of the following fields:

      • Physiology
      • Respiratory
      39.3
      Seconds
  • Question 18 - In a ward round, you come across a patient's treatment chart prescribed an...

    Incorrect

    • In a ward round, you come across a patient's treatment chart prescribed an antibiotic to fight his infection. This antibiotic is an inhibitor of cell wall synthesis.

      Which of the following antimicrobial drugs is prescribed to this patient?

      Your Answer: Metronidazole

      Correct Answer: Benzylpenicillin

      Explanation:

      Penicillins and cephalosporins are the major antibiotics that inhibit bacterial cell wall synthesis. They inactivate transpeptidases that help cross-link peptidoglycans in cell walls.

      Isoniazid decreases the synthesis of mycolic acids in mycobacterium.

      Clarithromycin binds to the 50S subunit of ribosomes and inhibits protein synthesis.

      Metronidazole and the other 5-nitroimidazole agents inhibit nucleic acid synthesis by forming toxic free radical metabolites in the bacterial cell that damage DNA.

      Tetracycline bind to 30S and prevent attachment of aminoacyl-tRNA.

    • This question is part of the following fields:

      • Infections
      • Pharmacology
      17.2
      Seconds
  • Question 19 - You see a 30-year-old man who has come to the department with a...

    Correct

    • You see a 30-year-old man who has come to the department with a very tender right elbow. On examination, the elbow is very hot and red, and appears to be acutely inflamed.
      Which SINGLE statement regarding acute inflammation is FALSE?

      Your Answer: Reduced extravascular osmotic pressure leads to oedema

      Explanation:

      Inflammation can be divided intoacute inflammation, which occurs over seconds, minutes, hours, and days, andchronic inflammation, which occurs over longer periods.
      Acute inflammationcommences within seconds or minutes following the injury of tissues. There are numerous potential stimuli for an acute inflammatory response including infections (bacterial, viral, fungal, parasitic), tissue necrosis, foreign bodies, and Immune reactions (hypersensitivity reactions). The chief cell type of acute inflammation is the neutrophil.
      There are three main processesthat occur in the acute inflammatory response:
      Increased blood flow
      Increased capillary permeability
      Neutrophil migration
      1. Increased blood flow:
      Vasoactive mediators are released, such as nitric oxide, histamine, bradykinins, and prostaglandin E2. These mediators cause vasodilatation and increased blood flow to the area (causing redness and heat).
      2. Increased capillary permeability:
      The vasoactive mediators also cause increased capillary permeability by causing endothelial cell contraction that widens the intercellular gaps of venules. This allows an outpouring of protein-rich fluid (exudate) into the extracellular tissues that results in a reduction of intravascular osmotic pressure and an increase in extravascular/interstitial pressure. The increased interstitial osmotic pressure leads to oedema.
      3. Neutrophil migration:
      Neutrophils leave the vasculature through the following sequence of events:
      Margination and rolling: neutrophils flow nearer the vessel wall, rather than in the axial stream, which is referred to as margination. Following margination the neutrophils begin rolling along the surface of the vascular endothelium.
      Activation and adhesion: then as a result of interaction with endothelial cell adhesion molecules (CAMs) that is mediated by selectins, the neutrophils are activated and adhere to the endothelium.
      Transmigration: once bound to the endothelium, neutrophils squeeze through gaps between adjacent endothelial cells into the interstitial fluid, in a process calleddiapedesis.

    • This question is part of the following fields:

      • General Pathology
      • Pathology
      49.5
      Seconds
  • Question 20 - Regarding shingles, which of the following statements is CORRECT: ...

    Incorrect

    • Regarding shingles, which of the following statements is CORRECT:

      Your Answer: You can catch shingles from a patient with chickenpox.

      Correct Answer: You can catch chickenpox from a patient with shingles.

      Explanation:

      After primary infection, VZV remains latent in sensory ganglia and in about 20% of patients will reactivate resulting in shingles, a painful vesicular rash in the related dermatome. Shingles usually affects older people and the immunocompromised. Shingles lesions are infectious to non-immune individuals who are at risk of developing chickenpox. Shingles can not be contracted directly from chickenpox, or from other cases of shingles. Shingles is treated with systemic antiviral treatment to reduce the severity and duration of pain, reduce complications, and reduce viral shedding.

    • This question is part of the following fields:

      • Microbiology
      • Pathogens
      39.1
      Seconds
  • Question 21 - A 61-year-old patient experiences a spontaneous rupture of his Achilles tendon following a...

    Correct

    • A 61-year-old patient experiences a spontaneous rupture of his Achilles tendon following a course of antibiotics

      Which of the antibiotics listed below is MOST likely to be the cause? 

      Your Answer: Ciprofloxacin

      Explanation:

      Tendinopathy and spontaneous tendon rupture are caused by fluoroquinolones, which are an uncommon but well-known cause. Tendon problems caused by fluoroquinolones are expected to affect 15 to 20 people per 100,000. Patients over the age of 60 are most likely to develop them.

      It usually affects the Achilles tendon, but it has also been described in cases involving the quadriceps, peroneus brevis, extensor pollicis longus, long head of biceps brachii, and rotator cuff tendons. The exact aetiology is uncertain, although the fluoroquinolone medication is thought to obstruct collagen activity and/or cut off blood supply to the tendon.

      Other factors linked to tendon rupture spontaneously include:
      Gout
      Treatment with corticosteroids
      Hypercholesterolaemia
      Long-term dialysis
      Kidney transplant
      Rheumatoid arthritis 

    • This question is part of the following fields:

      • Infections
      • Pharmacology
      7.6
      Seconds
  • Question 22 - A 56-year-old female visits her cardiologist complaining of a condition that has started...

    Incorrect

    • A 56-year-old female visits her cardiologist complaining of a condition that has started since he started her on amiodarone for atrial arrhythmia. The cardiologist recognised that she is experiencing a side effect of amiodarone.

      Which one of the following conditions will this woman NOT have?

      Your Answer: Peripheral neuropathy

      Correct Answer: Xanthopsia

      Explanation:

      Amiodarone is a class III potassium channel blocker used to treat multiple types of arrhythmias.

      Side effects include:
      1. pulmonary fibrosis
      2. blue discolouration of the skin
      3. phototoxicity
      4. corneal deposits
      5. hepatic necrosis
      6. thyroid dysfunction
      7. sleep disturbances
      8. peripheral neuropathy.

      Xanthopsia is a condition where the patient complains of seeing yellow lines and is seen in digoxin overdose.

    • This question is part of the following fields:

      • Cardiovascular Pharmacology
      • Pharmacology
      40.7
      Seconds
  • Question 23 - Which of the following conditions manifests hyperkalaemia as one of its symptoms? ...

    Incorrect

    • Which of the following conditions manifests hyperkalaemia as one of its symptoms?

      Your Answer: Type 1 renal tubular acidosis

      Correct Answer: Congenital adrenal hyperplasia

      Explanation:

      Plasma potassium greater than 5.5 mmol/L is hyperkalaemia or elevated plasma potassium level. Among the causes of hyperkalaemia include congenital adrenal hyperplasia.

      Congenital adrenal hyperplasia is a general term referring to autosomal recessive disorders involving a deficiency of an enzyme needed in cortisol and/or aldosterone synthesis. The level of cortisol and/or aldosterone deficiency affects the clinical manifestations of congenital adrenal hyperplasia. When it involves hypoaldosteronism, it can result in hyponatremia and hyperkalaemia. While hypercortisolism can cause hypoglycaemia.

      The other causes of hyperkalaemia may include renal failure, excess potassium supplementation, Addison’s disease (adrenal insufficiency), renal tubular acidosis (type 4), rhabdomyolysis, burns, trauma, Tumour lysis syndrome, acidosis, and medications such as ACE inhibitors, angiotensin receptor blockers, NSAIDs, beta-blockers, digoxin, and suxamethonium.

      Bartter’s syndrome is characterized by hypokalaemic alkalosis with normal to low blood pressure.

      Type 1 and 2 renal tubular acidosis both cause hypokalaemia.

      Gitelman’s syndrome is a defect of the distal convoluted tubule of the kidney. It causes metabolic alkalosis with hypokalaemia and hypomagnesemia.

      And excessive liquorice ingestion causes hypermineralocorticoidism and hypokalaemia as well. Thus, among the choices, only congenital adrenal hyperplasia can cause hyperkalaemia

      .

    • This question is part of the following fields:

      • Physiology
      • Renal Physiology
      15.2
      Seconds
  • Question 24 - Which of the following statements is correct regarding the partial pressure of oxygen...

    Incorrect

    • Which of the following statements is correct regarding the partial pressure of oxygen during respiration?

      Your Answer: Exhaled PO 2 < Alveolar PO 2 < Inhaled PO 2

      Correct Answer: Exhaled PO 2 > Alveolar PO 2

      Explanation:

      Because of humidification, inspired PO2 in the airways is less than inhaled PO2.
      Because of gas exchange, alveolar PO2 is less than inhaled or inspired PO2.
      Because of mixing with anatomical dead space (air that has not taken part in gas exchange, exhaled PO2 is greater than alveolar O2, and therefore that has relatively higher PO2 on the way out, but is less than inhaled or inspired PO2.
      Typical values for a resting young healthy male (in kPa) are shown below:
      -Inhaled air: PO221.2, PCO20.0
      -Inspired air in airways (after humidification): PO219.9, PCO20.0
      -Alveolar air (after equilibrium with pulmonary capillaries): PO213.3, PCO25.3
      -Exhaled air (after mixing with anatomical dead space air): PO215.5, PCO24.3

    • This question is part of the following fields:

      • Physiology
      • Respiratory
      42
      Seconds
  • Question 25 - Which of the following clinical features is a feature of a chronic extravascular...

    Incorrect

    • Which of the following clinical features is a feature of a chronic extravascular haemolytic anaemia:

      Your Answer: Raised serum conjugated bilirubin

      Correct Answer: Gallstones

      Explanation:

      Clinical features of haemolytic anaemia include:
      Anaemia
      Jaundice (caused by unconjugated bilirubin in plasma, bilirubin is absent from urine)
      Pigment gallstones
      Splenomegaly
      Ankle ulcers
      Expansion of marrow with, in children, bone expansion e.g. frontal bossing in beta-thalassaemia major
      Aplastic crisis caused by parvovirus

    • This question is part of the following fields:

      • Haematology
      • Pathology
      25.1
      Seconds
  • Question 26 - A 32-year-old female is diagnosed case of bipolar disorder and is on medication....

    Incorrect

    • A 32-year-old female is diagnosed case of bipolar disorder and is on medication. She presents to her psychiatric team with symptoms of severe depression. She is currently taking Lithium.

      Out of the following, which is TRUE regarding lithium?

      Your Answer: The normal therapeutic range is 2.0-2.5 mmol/l

      Correct Answer: It commonly causes a tremor

      Explanation:

      Lithium is the drug of choice for bipolar disorders but is commonly associated with side effects and toxicity.

      Fine hand tremor is very commonly seen and reported in as many as 50% of patients during the first week of therapy with Lithium. The tremor tends to reduce with time and is only present in around 5% of patients taking the medication two years or longer. Lithium tremors are more common with older age, presumably due to the additive effects of age-related essential tremors.

      Option The normal therapeutic range is 2.0-2.5 mmol/l: Lithium should be carefully monitored as it has a very low therapeutic index. The normal therapeutic range is 0.4-0.8 mmol/l. Levels should be checked one week after starting therapy and one week after every change in dosage. (Option Levels should be checked one month after starting therapy)

      Option It can induce hyperthyroidism: Lithium has a known effect on thyroid function. Lithium decreases the production of T4 and T3 and commonly causes hypothyroidism. More rarely, lithium causes hyperthyroidism due to thyroiditis.

      Option It can induce diabetes mellitus: Lithium can induce nephrogenic diabetes insipidus but not diabetes mellitus.

    • This question is part of the following fields:

      • CNS Pharmacology
      • Pharmacology
      36.9
      Seconds
  • Question 27 - The triage nurse asks if you will prescribe a dose of codeine phosphate...

    Incorrect

    • The triage nurse asks if you will prescribe a dose of codeine phosphate for a patient who is in a lot of pain. You discover that you are unable to prescribe it due to a contra-indication after evaluating the patient.

      The use of codeine phosphate is contraindicated in which of the following situations?

      Your Answer: Heart failure

      Correct Answer: Age under 12 years

      Explanation:

      Codeine phosphate is a mild opiate that can be used to treat mild to moderate pain when other pain relievers like paracetamol or ibuprofen have failed. It can also be used to treat diarrhoea and coughs that are dry or painful.

      The use of all opioids is contraindicated for the following reasons:
      Respiratory depression (acute)
      Patients who are comatose
      Head injury (opioid analgesics impair pupillary responses, which are crucial for neurological evaluation)
      Intracranial pressure has risen (opioid analgesics interfere with pupillary responses vital for neurological assessment)
      There’s a chance you’ll get paralytic ileus.

      The use of codeine phosphate is contraindicated in the following situations:
      Because of the significant risk of respiratory side effects in children under the age of 12, it is not recommended for children under the age of 12.

      Patients of any age who have been identified as ultra-rapid codeine metabolizers (CYP2D6 ultra-rapid metabolizers)

      Because codeine can pass through breast milk to the baby and because mothers’ ability to metabolise codeine varies greatly, it is especially dangerous in breastfeeding mothers.

      If other painkillers, such as paracetamol or ibuprofen, fail to relieve acute moderate pain in children over the age of 12, codeine should be used. In children with obstructive sleep apnoea who received codeine after tonsillectomy or adenoidectomy, a significant risk of serious and life-threatening adverse reactions has been identified.

    • This question is part of the following fields:

      • CNS Pharmacology
      • Pharmacology
      30.9
      Seconds
  • Question 28 - What is the mechanism of action of cetirizine: ...

    Correct

    • What is the mechanism of action of cetirizine:

      Your Answer: H1-receptor antagonist

      Explanation:

      Cetirizine is a competitive inhibitor at the H1-receptor (an antihistamine).

    • This question is part of the following fields:

      • Pharmacology
      • Respiratory
      10.3
      Seconds
  • Question 29 - During quiet respiration, position of the right oblique fissure can be marked by...

    Correct

    • During quiet respiration, position of the right oblique fissure can be marked by a line drawn on the thoracic wall that:

      Your Answer: Begins at the spinous process of T4, crosses the fifth intercostal space laterally and follows the contour of rib 6 anteriorly.

      Explanation:

      During quiet respiration, the approximate position of the right oblique fissure can be marked by a line on the thoracic wall that begins at the spinous process of vertebra T4, crosses the fifth intercostal space laterally and then follows the contour of rib 6 anteriorly.

    • This question is part of the following fields:

      • Anatomy
      • Thorax
      8.8
      Seconds
  • Question 30 - Which of the following is an adverse effect of carbamazepine: ...

    Incorrect

    • Which of the following is an adverse effect of carbamazepine:

      Your Answer: Ototoxicity

      Correct Answer: Aplastic anaemia

      Explanation:

      Common adverse effects include nausea and vomiting, sedation, dizziness, headache, blurred vision and ataxia. These adverse effects are dose related and are most common at the start of treatment.
      Other adverse effects include:
      Allergic skin reactions (and rarely, more serious dermatological conditions)
      Hyponatraemia (avoid concomitant use with diuretics)
      Leucopenia, thrombocytopenia and other blood disorders including aplastic anaemia
      Hepatic impairment

    • This question is part of the following fields:

      • Central Nervous System
      • Pharmacology
      19.4
      Seconds
  • Question 31 - A 76-year-old man presents with complaints of double vision. Upon physical examination, it...

    Correct

    • A 76-year-old man presents with complaints of double vision. Upon physical examination, it was observed that he exhibits left-sided hemiplegia and left-sided loss of joint position sense, vibratory sense and discriminatory touch. In addition, he has the inability to abduct his right eye and is holding his head towards the right side. A CT scan was ordered and showed that he has suffered a right-sided stroke.

      Branches of which of the following arteries are most likely implicated in the case?

      Your Answer: Basilar artery

      Explanation:

      Inferior medial pontine syndrome, also known as Foville syndrome, is one of the brainstem stroke syndromes which occurs when there is infarction of the medial inferior aspect of the pons due to occlusion of the paramedian branches of the basilar artery.

      It is characterized by ipsilateral sixth nerve palsy, facial palsy, contralateral hemiparesis, contralateral loss of proprioception and vibration, ipsilateral ataxia, ipsilateral facial weakness, and lateral gaze paralysis and diplopia.

    • This question is part of the following fields:

      • Anatomy
      • Central Nervous System
      43.3
      Seconds
  • Question 32 - Chronic myeloid leukaemia is most common in middle-aged and elderly people. It is...

    Incorrect

    • Chronic myeloid leukaemia is most common in middle-aged and elderly people. It is responsible for 20% of all leukemias.

      Which of the following statements about CML is NOT TRUE?

      Your Answer: The presence of a chloroma is diagnostic of a blast crisis

      Correct Answer: Serum B12 is typically low

      Explanation:

      Chronic myeloid leukaemia is most common in middle-aged and elderly people. It is responsible for 20% of all leukemias. The majority of CML patients experience fatigue, weight loss, and excessive sweating.

      The Philadelphia chromosome is found in over 90% of CML cases. A balanced translocation between chromosomes 9 and 22 is known as the Philadelphia chromosome.

      Because white cells produce a B12 binding protein, serum B12 levels in CML are typically high.

      In CML, the neutrophil alkaline phosphatase score is usually low.

      Almost all patients with CML eventually progress to blast crisis, though this can take up to ten years. If any of the following features are present in a CML patient, a blast crisis is diagnosed:
      In the blood or bone marrow, there are more than 20% myeloblasts or lymphoblasts.
      On a bone marrow biopsy, large clusters of blasts were discovered.

      CML can be treated with tyrosine kinase inhibitors like imatinib and dasatinib if a chloroma (a solid tumour made up of myeloblasts that grows outside of the bone marrow) is present.

    • This question is part of the following fields:

      • Haematology
      • Pathology
      27.6
      Seconds
  • Question 33 - A 55 year old man presents to ED complaining of leg weakness. Your...

    Correct

    • A 55 year old man presents to ED complaining of leg weakness. Your colleague has examined the patient and suspects femoral nerve palsy. Which of the following clinical features would you LEAST expect to see on examination of this patient:

      Your Answer: Weakness of hip extension

      Explanation:

      Damage to the femoral nerve results in weakness of hip flexion and knee extension and loss of sensation over the anterior thigh and the anteromedial knee, medial leg and medial foot.

    • This question is part of the following fields:

      • Anatomy
      • Lower Limb
      29.4
      Seconds
  • Question 34 - A 39-year-old woman's son with meningococcal meningitis was recently admitted to the Paediatric...

    Incorrect

    • A 39-year-old woman's son with meningococcal meningitis was recently admitted to the Paediatric Intensive Care Unit. She is currently 22 weeks pregnant and is concerned about the possibility of her also contracting the disease as she cared closely for her son during his admission.

      Which antibiotic would be the MOST appropriate choice for chemoprophylaxis in this case?

      Your Answer: Ceftriaxone

      Correct Answer: Ciprofloxacin

      Explanation:

      Ciprofloxacin is recommended for use as meningococcal chemoprophylaxis in all age groups and in pregnancy, and is the most appropriate for this patient.

      However, rifampicin is the drug of choice for meningococcal chemoprophylaxis because it is licensed for chemoprophylaxis, but multiple doses are necessary and it is not readily available in community pharmacies. It also interacts with oral contraceptives.

    • This question is part of the following fields:

      • Microbiology
      • Specific Pathogen Groups
      25
      Seconds
  • Question 35 - The blood test reports of a 56-year-old female are sent for your review....

    Incorrect

    • The blood test reports of a 56-year-old female are sent for your review. She seems acutely sick and has had multiple infections over the past few months. Her complete blood count report shows neutropenia.

      Which one of the following options is true with regards to neutropenia?

      Your Answer: It is commonly caused by parasitic infections

      Correct Answer: It can be caused by both radiotherapy and chemotherapy

      Explanation:

      A total neutrophil count of less than 2 x 109/L is defined as neutropenia. It can be caused by the following:
      1. viral infections
      2. SLE
      3. RA
      4. hypersplenism
      5. chemo- and radiotherapy
      6. vitamin B12 and folate deficiency
      7. drug reactions

    • This question is part of the following fields:

      • Haematology
      • Pathology
      50.8
      Seconds
  • Question 36 - During bedside rounds, an 82-year old female in the Medicine Ward complains of...

    Correct

    • During bedside rounds, an 82-year old female in the Medicine Ward complains of pain and tingling of all fingers of the right hand. The attending physician is considering carpal tunnel syndrome.

      Which of the following is expected to undergo atrophy in carpal tunnel syndrome?

      Your Answer: The thenar eminence

      Explanation:

      Carpal tunnel syndrome (CTS) is an entrapment neuropathy caused by compression of the median nerve as it travels through the wrist’s carpal tunnel. It is the most common nerve entrapment neuropathy, accounting for 90% of all neuropathies. Early symptoms of carpal tunnel syndrome include pain, numbness, and paraesthesia’s. These symptoms typically present, with some variability, in the thumb, index finger, middle finger, and the radial half (thumb side) of the ring finger. Pain also can radiate up the affected arm. With further progression, hand weakness, decreased fine motor coordination, clumsiness, and thenar atrophy can occur.

      The muscles innervated by the median nerve can be remembered using the mnemonic ‘LOAF’:
      L– lateral two lumbricals
      O– Opponens pollicis
      A– Abductor pollicis
      F– Flexor pollicis brevis

      In the early presentation of the disease, symptoms most often present at night when lying down and are relieved during the day. With further progression of the disease, symptoms will also be present during the day, especially with certain repetitive activities, such as when drawing, typing, or playing video games. In more advanced disease, symptoms can be constant.

      Typical occupations of patients with carpal tunnel syndrome include those who use computers for extended periods of time, those who use equipment that has vibration such as construction workers, and any other occupation requiring frequent, repetitive movement.

    • This question is part of the following fields:

      • Anatomy
      • Upper Limb
      14.3
      Seconds
  • Question 37 - Regarding cardiac excitation-contraction coupling, which of the following statements is CORRECT: ...

    Incorrect

    • Regarding cardiac excitation-contraction coupling, which of the following statements is CORRECT:

      Your Answer: Digoxin has a negative inotropic effect.

      Correct Answer: The Treppe effect refers to an increase in contractility secondary to an increase in heart rate.

      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). 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. When more action potentials occur per unit time, more Ca2+enters the cell during the AP plateau, more Ca2+is stored in the SR, more Ca2+is released from the SR and thus more Ca2+is left inside the cell and greater tension is produced during contraction. 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. Cardiac glycosides such as digoxin have a positive inotropic effect.

    • This question is part of the following fields:

      • Cardiovascular
      • Physiology
      30.2
      Seconds
  • Question 38 - C3 deficiency leads to particular susceptibility of infection with which of the following:...

    Incorrect

    • C3 deficiency leads to particular susceptibility of infection with which of the following:

      Your Answer: Neisseria spp.

      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

    • This question is part of the following fields:

      • Immune Responses
      • Pathology
      8
      Seconds
  • Question 39 - A patient suffers an injury to his thigh that damages the nerve that...

    Incorrect

    • A patient suffers an injury to his thigh that damages the nerve that innervates pectineus.
      Which of the following nerves has been damaged in this case? Select ONE answer only.

      Your Answer: Sciatic nerve

      Correct Answer: Femoral nerve

      Explanation:

      Pectineus is innervated by the femoral nerve. It may also receive a branch from the obturator nerve.

    • This question is part of the following fields:

      • Anatomy
      • Lower Limb
      14.4
      Seconds
  • Question 40 - The hypothalamus produces antidiuretic hormone (ADH), also known as vasopressin, which is a...

    Correct

    • The hypothalamus produces antidiuretic hormone (ADH), also known as vasopressin, which is a peptide hormone. It is important for maintaining water and electrolyte balance, as well helping control arterial pressure.

      To have an effect on blood arteries, ADH binds to which of the following receptors?

      Your Answer: V 1 receptor

      Explanation:

      ADH, or antidiuretic hormone, is a hormone that regulates water and electrolyte balance. It is released in response to a variety of events, the most important of which are higher plasma osmolality or lower blood pressure. ADH increases plasma volume and blood pressure via acting on the kidneys and peripheral vasculature.

      It causes vasoconstriction by binding to peripheral V1 Receptors on vascular smooth muscle via the IP3 signal transduction and Rho-kinase pathways. The systemic vascular resistance and arterial pressure rise as a result. High levels of ADH appear to be required for this to have a major impact on arterial pressure, such as in hypovolaemic shock.

    • This question is part of the following fields:

      • Physiology
      • Renal Physiology
      19.8
      Seconds
  • Question 41 - Which of the following statements is correct with regards to Hodgkin's lymphoma?
    ...

    Correct

    • Which of the following statements is correct with regards to Hodgkin's lymphoma?

      Your Answer: Most patients present with painless asymmetrical lymphadenopathy, with cervical nodes involved most commonly.

      Explanation:

      Lymphoma is a cancer of the lymphatic system, which is part of the body’s germ-fighting network. They are a group of diseases that are caused by malignant lymphocytes. These malignant cells accumulate in lymph nodes and other lymphoid tissue, giving rise to the characteristic clinical feature of lymphadenopathy.
      They can be subdivided into Hodgkin lymphoma (HL) which are characterised by the presence of Reed-Sternberg cells, and non-Hodgkin lymphoma (NHL).
      Characteristics of HL include:
      1. can present at any age but is rare in children and has a peak incidence in young adults,
      2. almost 2:1 male predominance.
      3. presents with painless, asymmetrical, firm and discrete enlargement of superficial lymph nodes.
      4. cervical node involvement in 60-70% of cases,
      5. axillary node involvement in 10-15%
      6. inguinal node involvement in 6-12%.
      7. modest splenomegaly during the course of the disease in 50% of patients
      8. may occasionally have liver enlargement
      9. bone marrow failure involvement is unusual in early disease.
      Approximately 85% of patients are cured, but the prognosis depends on age, stage and histology.
      Two well‐known but rare symptoms in HL are alcohol‐induced pain and pruritus.

    • This question is part of the following fields:

      • Haematology
      • Pathology
      13.1
      Seconds
  • Question 42 - Disease specific immunoglobulin is available for all of the following infectious diseases EXCEPT...

    Incorrect

    • Disease specific immunoglobulin is available for all of the following infectious diseases EXCEPT for:

      Your Answer: Varicella-zoster

      Correct Answer: Hepatitis A

      Explanation:

      Disease specific immunoglobulins are available for:
      hepatitis B
      rabies
      tetanus
      varicella-zoster
      Normal immunoglobulin can be used to confer protection against hepatitis A.

    • This question is part of the following fields:

      • Immunoglobulins And Vaccines
      • Pharmacology
      16.2
      Seconds
  • Question 43 - Streptococcus viridans has developed subacute bacterial endocarditis in your patient. Which of the...

    Correct

    • Streptococcus viridans has developed subacute bacterial endocarditis in your patient. Which of the following locations is most likely to be the organism's origin?

      Your Answer: Oral cavity

      Explanation:

      Streptococci that are alpha-haemolytic, such as Streptococcus viridans, are major components of the flora in the oral cavity.

    • This question is part of the following fields:

      • Infections
      • Microbiology
      17.4
      Seconds
  • Question 44 - Regarding the resting membrane potential, which of the following statements is CORRECT: ...

    Incorrect

    • Regarding the resting membrane potential, which of the following statements is CORRECT:

      Your Answer: The resting membrane potential is primarily determined by the Na + equilibrium potential.

      Correct Answer: The resting cell membrane is more permeable to K + ions than to Na + ions.

      Explanation:

      A membrane potential is a property of all cell membranes, but the ability to generate an action potential is only a property of excitable tissues. The resting membrane is more permeable to K+and Cl-than to other ions (and relatively impermeable to Na+); therefore the resting membrane potential is primarily determined by the K+equilibrium potential. At rest the inside of the cell is negative relative to the outside. In most neurones the resting potential has a value of approximately -70 mV.

    • This question is part of the following fields:

      • Basic Cellular
      • Physiology
      28.4
      Seconds
  • Question 45 - You've been summoned to your Emergency Department resuscitation area to see a patient....

    Correct

    • 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: 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 failure

      Atropine 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
      36.5
      Seconds
  • Question 46 - Which of the following pathogens is the common cause of diarrhoea in a...

    Correct

    • Which of the following pathogens is the common cause of diarrhoea in a patient who has had a prolonged course of a broad spectrum of antibiotics?

      Your Answer: Clostridium difficile

      Explanation:

      Clostridium difficile is the most likely cause of diarrhoea after a long course of broad-spectrum antibiotic treatment.

      Clostridium difficile-associated diarrhoea appeared to be linked to an increase in the usage of third-generation cephalosporins.

    • This question is part of the following fields:

      • Microbiology
      • Pathogens
      7
      Seconds
  • Question 47 - A 7-year old boy is referred to the Paediatrics Department due to slurred...

    Correct

    • A 7-year old boy is referred to the Paediatrics Department due to slurred speech. Upon further examination, the attending physician noted the presence of dysdiadochokinesia, intention tremors, and nystagmus. An MRI is taken, which revealed a brain tumour.

      Which of the following options is the most probable diagnosis given the clinical features of the patient?

      Your Answer: Astrocytoma of cerebellum

      Explanation:

      Pilocytic astrocytoma (PCA), previously known as cystic cerebellar astrocytoma or juvenile pilocytic astrocytoma, was first described in 1931 by Harvey Cushing, based on a case series of cerebellar astrocytomas; though he never used these terms but rather described a spongioblastoma. They are low-grade, and usually well-circumscribed tumours, which tend to occur in young patients. By the World Health Organization (WHO) classification of central nervous system tumours, they are considered grade I gliomas and have a good prognosis.

      PCA most commonly occurs in the cerebellum but can also occur in the optic pathway, hypothalamus, and brainstem. They can also occur in the cerebral hemispheres, although this tends to be the case in young adults. Presentation and treatment vary for PCA in other locations. Glial cells include astrocytes, oligodendrocytes, ependymal cells, and microglia. Astrocytic tumours arise from astrocytes and are the most common tumour of glial origin. The WHO 2016 categorized these tumours as either diffuse gliomas or other astrocytic tumours. Diffuse gliomas include grade II and III diffuse astrocytomas, grade IV glioblastoma, and diffuse gliomas of childhood. The other astrocytic tumours group include PCA, pleomorphic xanthoastrocytoma, subependymal giant cell astrocytoma, and anaplastic pleomorphic xanthoastrocytoma.

      PCA can present with symptoms secondary to the posterior fossa mass effect. This may include obstructive hydrocephalus, with resultant headache, nausea and vomiting, and papilledema. If hydrocephalus occurs before the fusion of the cranial sutures (<18-months-of-age), then an increase in head circumference will likely occur. Lesions of the cerebellar hemisphere result in peripheral ataxia, dysmetria, intention tremor, nystagmus, and dysarthria. In contrast, lesions of the vermis cause a broad-based gait, truncal ataxia, and titubation. Posterior fossa lesions can also cause cranial nerve palsies. Diplopia may occur due to abducens palsy from the stretching of the nerve. They may also have blurred vision due to papilledema. Seizures are rare with posterior fossa lesions.

    • This question is part of the following fields:

      • Anatomy
      • Central Nervous System
      16.4
      Seconds
  • Question 48 - On which of the following types of receptors does loperamide act? ...

    Incorrect

    • On which of the following types of receptors does loperamide act?

      Your Answer: Muscarinic receptors

      Correct Answer: Opioid receptors

      Explanation:

      Loperamide inhibits acetylcholine release from the myenteric plexus acts by action on opioid mu-receptors, and this then reduces bowel motility. The intestinal transit time is increased, thereby facilitating water reabsorption.

    • This question is part of the following fields:

      • Gastrointestinal
      • Pharmacology
      8.3
      Seconds
  • Question 49 - Which of the following nerves supplies the abductor pollicis brevis? ...

    Correct

    • Which of the following nerves supplies the abductor pollicis brevis?

      Your Answer: The recurrent branch of the median nerve

      Explanation:

      Abductor pollicis brevis is innervated by the recurrent (thenar) branch of median nerve (root value C8 and T1).

    • This question is part of the following fields:

      • Anatomy
      • Upper Limb
      16.2
      Seconds
  • Question 50 - ACE inhibitors are indicated for all of the following EXCEPT for: ...

    Incorrect

    • ACE inhibitors are indicated for all of the following EXCEPT for:

      Your Answer: Diabetic nephropathy

      Correct Answer: Angina

      Explanation:

      ACE inhibitors have many uses and are generally well tolerated. They are indicated for:

      • Heart failure
      • Hypertension
      • Diabetic nephropathy
      • Secondary prevention of cardiovascular events

    • This question is part of the following fields:

      • Cardiovascular
      • Pharmacology
      41.7
      Seconds
  • Question 51 - A 60-year-old male presents to the genitourinary clinic with dysuria and urinary frequency...

    Incorrect

    • A 60-year-old male presents to the genitourinary clinic with dysuria and urinary frequency complaints. He has a past medical history of benign prostate enlargement, for which he has been taking tamsulosin. There is blood, protein, leucocytes, and nitrites on a urine dipstick. Fresh blood tests were sent, and his estimated GFR is calculated to be >60 ml/minute. A urinary tract infection (UTI) diagnosis is made, and he is prescribed antibiotics. Out of the following, which antibiotic is most appropriate to be prescribed to this patient?

      Your Answer: Cefalexin

      Correct Answer: Ciprofloxacin

      Explanation:

      URINARY TRACT INFECTIONS IN ADULT MEN
      Symptomatic urinary tract infections are much less common in men than in women, and all UTIs
      in men are considered complicated UTIs. Men with UTIs should be evaluated for predisposing or
      causative factors.

      Uncomplicated cystitis

      • Fosfomycin, oral, 3 g as a single dose.

      If fosfomycin is unavailable:

      • Nitrofurantoin, oral, 100 mg 6 hourly for 5 days.

      Do not use nitrofurantoin or fosfomycin if there is any suspicion of early pyelonephritis as they do
      not achieve adequate renal tissue levels.
      If there are any factors precluding the use of the above agents, then a beta-lactam should be used.
      Options include:
      Cefixime 200 mg PO 12 hourly for 7 days
      OR
      Cefpodoxime 100 mg PO 12 hourly for 7 days

      Complicated cystitis
      Adults

      • Ciprofloxacin 500 mg PO 12 hourly
        OR
      • Levofloxacin 750 mg PO once daily

      Empiric antibiotic therapy should be changed based upon the bacteria isolated and its
      antimicrobial susceptibility.
      Treat for a total of 7–14 days

    • This question is part of the following fields:

      • Infections
      • Pharmacology
      38.1
      Seconds
  • Question 52 - Which of the following best describes the mechanism of action of aspirin: ...

    Correct

    • Which of the following best describes the mechanism of action of aspirin:

      Your Answer: Cyclo-oxygenase (COX) inhibitor

      Explanation:

      Aspirin is a non-steroidal anti-inflammatory drug (NSAID). Aspirin irreversibly inhibits cyclooxygenase (COX) enzymes and the resulting inhibition of prostaglandin synthesis results in analgesic, antipyretic and to a lesser extent anti-inflammatory actions.

    • This question is part of the following fields:

      • Central Nervous System
      • Pharmacology
      6.7
      Seconds
  • Question 53 - You're a member of the cardiac arrest team, and you're helping to resuscitate...

    Correct

    • You're a member of the cardiac arrest team, and you're helping to resuscitate an elderly gentleman who had collapsed at home. The team leader requests that you administer an adrenaline shot.

      Which of the following statements about adrenaline is FALSE?

      Your Answer: The IM dose in anaphylaxis is 1 ml of 1:1000

      Explanation:

      Adrenaline (epinephrine) is a sympathomimetic amine that binds to alpha- and beta-adrenergic receptors and acts as an agonist. It is active at both alpha and beta receptors in roughly equal amounts.

      When taken orally, it becomes inactive. Subcutaneous absorption is slower than intramuscular absorption. In cardiac arrest, it is well absorbed from the tracheal mucosa and can be given through an endotracheal tube.

      At the adrenergic synapse, catechol-O-methyltransferase (COMT) and monoamine oxidase (MAO) metabolise it primarily. The inactive products are then passed through the kidneys and excreted in the urine.

      In adult cardiac arrest, the IV dose is 1 mg, which is equal to 10 ml of 1:10000 or 1 ml of 1:1000. In anaphylaxis, the IM dose is 0.5 ml of 1:1000. (500 mcg).

      In open-angle glaucoma, adrenaline causes mydriasis and lowers pressure.

      Adrenaline is used in cardiopulmonary resuscitation, the treatment of severe croup, and the emergency management of acute allergic and anaphylactic reactions (as a nebuliser solution).

    • This question is part of the following fields:

      • Cardiovascular Pharmacology
      • Pharmacology
      17
      Seconds
  • Question 54 - What is the main mechanism of action of metoclopramide: ...

    Incorrect

    • What is the main mechanism of action of metoclopramide:

      Your Answer: Histamine-H2 antagonist

      Correct 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.

    • This question is part of the following fields:

      • Central Nervous System
      • Pharmacology
      14.8
      Seconds
  • Question 55 - Antispasmodic drugs are primarily indicated in which of the following conditions: ...

    Correct

    • Antispasmodic drugs are primarily indicated in which of the following conditions:

      Your Answer: Irritable bowel syndrome

      Explanation:

      Antispasmodics, such as antimuscarinics, may be used in the management of irritable bowel syndrome. Other antispasmodics used include direct-acting smooth muscle relaxants such as mebeverine, alverine, and peppermint oil. Antispasmodics are contraindicated in bowel obstruction and severe inflammatory bowel disease. Antispasmodics are occasionally of value in treating abdominal cramp associated with diarrhoea but they should not be used for primary treatment. Antispasmodics should be avoided in young children with gastroenteritis because they are rarely effective and have troublesome side effects. Antimuscarinics are contraindicated in urinary retention.

    • This question is part of the following fields:

      • Gastrointestinal
      • Pharmacology
      19.5
      Seconds
  • Question 56 - Following a decrease in extracellular volume, which of the following is a reaction...

    Correct

    • Following a decrease in extracellular volume, which of the following is a reaction to enhanced sympathetic innervation of the kidney:

      Your Answer: Release of renin

      Explanation:

      The RAS pathway begins with renin cleaving its substrate, angiotensinogen (AGT), to produce the inactive peptide, angiotensin I, which is then converted to angiotensin II by endothelial angiotensin-converting enzyme (ACE). ACE activation of angiotensin II occurs most extensively in the lung. Angiotensin II mediates vasoconstriction as well as aldosterone release from the adrenal gland, resulting in sodium retention and increased blood pressure.

    • This question is part of the following fields:

      • Physiology
      • Renal
      20.8
      Seconds
  • Question 57 - Which of the following does NOT increase free ionised calcium levels: ...

    Correct

    • Which of the following does NOT increase free ionised calcium levels:

      Your Answer: Calcitonin

      Explanation:

      Calcium homeostasis is primarily controlled by three hormones: parathyroid hormone, activated vitamin D and calcitonin.

      Parathyroid hormone acts on the kidneys to increase calcium reabsorption in the distal tubule by activating Ca2+entry channels in the apical membrane and the Ca2+ATPase pump in the basolateral membrane (and to decrease phosphate reabsorption in the proximal tubule).

      Activated vitamin D acts to increase calcium reabsorption in the distal tubule via activation of a basolateral Ca2+ATPase pump (and to increase phosphate reabsorption).

      Calcitonin acts to inhibit renal reabsorption of calcium (and phosphate).

    • This question is part of the following fields:

      • Physiology
      • Renal
      17.7
      Seconds
  • Question 58 - A 26 year old horse rider has a bad fall and sustains a...

    Correct

    • A 26 year old horse rider has a bad fall and sustains a neck injury which displays the following signs:
      - ability to extend the wrist against gravity
      - paralysis of the hands, trunk, and legs
      - absent sensation in the fingers and medial upper arms
      - normal sensation over the thumbs
      - absent sensation in chest, abdomen, and legs

      What is the neurological level of the injury?

      Your Answer: C6

      Explanation:

      C1 – C4 INJURY
      Most severe of the spinal cord injury levels; paralysis in arms, hands, trunk and legs; patient may not be able to breathe on his or her own, cough, or control bowel or bladder movements; ability to speak is sometimes impaired or reduced

      C5 INJURY
      Person can raise his or her arms and bend elbows; likely to have some or total paralysis of wrists, hands, trunk and legs; can speak and use diaphragm, but breathing will be weakened

      C6 INJURY
      Nerves affect wrist extension; paralysis in hands, trunk and legs, typically; should be able to bend wrists back; can speak and use diaphragm, but breathing will be weakened

      C7 INJURY
      Nerves control elbow extension and some finger extension; most can straighten their arm and have normal movement of their shoulders

      C8 INJURY
      Nerves control some hand movement; should be able to grasp and release objects

      C5 – Elbow flexors (biceps, brachialis)
      C6 – Wrist extensors (extensor carpi radialis longus and brevis)
      C7 – Elbow extensors (triceps)
      C8 – Finger flexors (flexor digitorum profundus) to the middle finger

      C5 – Elbow flexed at 90 degrees, arm at the patient’s side and forearm supinated
      C6 – Wrist in full extension
      C7 – Shoulder is neutral rotation, adducted and in 90 degrees of flexion with elbow in 45 degrees of flexion
      C8 –Full flexed position of the distal phalanx with the proximal finger joints stabilized in a extended position

    • This question is part of the following fields:

      • Anatomy
      • Central Nervous System
      50.8
      Seconds
  • Question 59 - A 27-year-old female is brought to the Emergency Department by ambulance with extensive...

    Correct

    • A 27-year-old female is brought to the Emergency Department by ambulance with extensive bleeding from her upper arm following a fall from a bicycle onto a fence. On inspection her biceps brachii muscle has been lacerated.
      How will the muscle heal from this injury? Select ONE answer only.

      Your Answer: Satellite cells will produce a small number of regenerated myocytes

      Explanation:

      Muscle heals with fibrous tissue to form a scar. Once cut, it will never regain its previous bulk or power. Within the scar a small number of myocytes (muscle cells) may be seen, which are formed from satellite cells but they contribute little to the function of the muscle overall.
      In more widespread ischaemic injury, such as critical ischaemic limb due to arterial compromise, or in compartment syndrome, damaged myocytes are replaced diffusely with fibrous tissue. This fibrous tissue contracts and reduces movement, and in extreme cases can pull the limb into abnormal positions such as in Volkmann’s ischaemic contracture of the forearm.

    • This question is part of the following fields:

      • General Pathology
      • Pathology
      38.2
      Seconds
  • Question 60 - A 60-year-old female is referred to the Oncology clinic due to the presence...

    Incorrect

    • A 60-year-old female is referred to the Oncology clinic due to the presence of lumps in her neck. There is a non-tender enlargement of several groups of cervical lymph nodes on examination. She is sent for a lymph node biopsy. The results show the presence of lymphoma cells, but there are no Reed-Sternberg cells.

      Which one is most appropriate for this case out of the following diagnoses?

      Your Answer: Hodgkin’s lymphoma

      Correct Answer: Non-Hodgkin’s lymphoma

      Explanation:

      Non-Hodgkin’s Lymphoma (NHL) causes neoplastic transformation of both B cell (85%) and T cell (15%) lines.

      The most common presentation is with enlarged, rubbery, painless lymph nodes. The patient may also have B symptoms which consist of night sweats, weight loss and fevers. Multiple myeloma most commonly presents with bone pain, especially in the back and ribs.

      The presence of Reed-Sternberg cells characterises Hodgkin’s lymphoma. Acute lymphoblastic leukaemia will present with features of anaemia, thrombocytopenia and leukopenia. The most common symptoms of chronic lymphocytic leukaemia are fatigue, night sweats and low-grade fever.

      The peak incidence of NHL is in the 50-70 years age group, it affects men and women equally, but affects the Caucasian population more commonly than black and Asian ethnic groups.
      The following are recognised risk factors for NHL:
      Chromosomal translocations and molecular rearrangements
      Epstein-Barr virus infection
      Human T-cell leukaemia virus type-1 (HTLV-1)
      Hepatitis C
      Congenital and acquired immunodeficiency states
      Autoimmune disorders, e.g. Sjogren’s syndrome and Hashimoto’s thyroiditis

    • This question is part of the following fields:

      • Haematology
      • Pathology
      47.5
      Seconds
  • Question 61 - Which of the following statements is correct with regards to insulin receptors? ...

    Incorrect

    • Which of the following statements is correct with regards to insulin receptors?

      Your Answer: Insulin receptors are G-protein coupled receptors.

      Correct Answer: Insulin has its intracellular effects via activation of tyrosine kinase.

      Explanation:

      Most cells have insulin receptors present on them which can be sequestered into the cell to inactivate them. These receptors consist of two extracellular alpha subunits which contain the insulin-binding site and two transmembrane beta subunits. Because insulin is a polypeptide hormone, it must act via cell surface receptors as it is unable to readily cross the cell membrane. On binding to the receptor, the beta subunit of insulin autophosphorylation, which activates tyrosine kinase. As a result, there is an intracellular cascade of phosphorylation, causing a translocation of the glucose transporter GLUT4 and GLUT-1 to the plasma membrane of the affected cell. This facilitates glucose entry.

    • This question is part of the following fields:

      • Endocrine
      • Physiology
      33.6
      Seconds
  • Question 62 - Due to a traffic accident, a male patient was unable to lift his...

    Correct

    • Due to a traffic accident, a male patient was unable to lift his arm, indicating an injury at the glenohumeral joint. Based on the patient’s current condition, which nerve or nerves are may likely damaged?

      Your Answer: Axillary and suprascapular nerve

      Explanation:

      A suprascapular nerve injury causes numbness in the shoulder, as well as weakness in abduction and external rotation.

      Damage to the axillary nerve can result in shoulder or arm muscle weakness, as well as difficulty lifting the arm. This is because the deltoid and supraspinatus muscles, which are innervated by the axillary and suprascapular nerves, are responsible for abduction of the arm at the shoulder joint.

    • This question is part of the following fields:

      • Anatomy
      • Upper Limb
      28
      Seconds
  • Question 63 - Liquefactive necrosis is most commonly seen in which of the following conditions: ...

    Incorrect

    • Liquefactive necrosis is most commonly seen in which of the following conditions:

      Your Answer: Myocardial infarction

      Correct Answer: Ischaemic stroke

      Explanation:

      Liquefactive necrosis results in the loss of all cellular structure and the formation of a soft, semi-solid mass. This is commonly seen in the brain after a cerebral infarction.

    • This question is part of the following fields:

      • Inflammatory Responses
      • Pathology
      13.5
      Seconds
  • Question 64 - The interquartile range (IQ) is often displayed using which of the following: ...

    Correct

    • The interquartile range (IQ) is often displayed using which of the following:

      Your Answer: Box and whisker plot

      Explanation:

      A boxplot is a vertical or horizontal rectangle used to display the interquartile range, with the ends of the rectangle corresponding to the upper and lower quartiles of the data values. The box contains 50% of the data values. A line drawn through the rectangle corresponds to the median value. Whiskers, starting at the ends of the rectangle usually indicate the minimum and maximum values, therefore the entire box and whisker plot represents the range. Any outliers can be plotted independent of the box and whisker plot.

    • This question is part of the following fields:

      • Evidence Based Medicine
      • Statistics
      7.4
      Seconds
  • Question 65 - A 40-year-old man with reduced urine output, nausea, and confusion also has a...

    Correct

    • A 40-year-old man with reduced urine output, nausea, and confusion also has a 150% rise of creatinine from baseline over the past 7 days. A diagnosis of acute kidney injury (AKI) is made after more tests are done.

      His AKI stage is?

      Your Answer: Stage 2

      Explanation:

      This patient with a 150% rise of creatinine above baseline within 7 days has stage 2 Acute kidney injury (AKI).

      AKI stages are as follows:
      Stage 1
      Creatinine rise of 26 micromole/L or more within 48 hours, or
      Creatinine rise of 50-99% from baseline within 7 days (1.5-1.99 x baseline),or
      Urine output <0.5 mL/kg/hour for more than 6 hours Stage 2
      Creatinine rise of 100-199% from baseline within 7 days (2.0-2.99 x baseline),or
      Urine output <0.5 mL/kg/hour for more than 12 hours Stage 3
      Creatinine rise of 200% or more from baseline within 7 days (3.0 or more x baseline), or
      Creatinine rise to 354 micromole/L or more with acute rise of 26 micromole/L or more within 48 hours or 50% or more rise within 7 days, or
      Urine output <0.3 mL/kg/hour for 24 hours or anuria for 12 hours

    • This question is part of the following fields:

      • General Pathology
      • Pathology
      19.3
      Seconds
  • Question 66 - On his stool culture, a patient with a diarrhoeal illness grows Escherichia coli.

    What...

    Correct

    • On his stool culture, a patient with a diarrhoeal illness grows Escherichia coli.

      What SINGLE statement about Escherichia coli is true?

      Your Answer: Most serotypes are harmless

      Explanation:

      Escherichia coli is a Gram-negative, non-spore forming, facultative anaerobic, rod-shaped bacterium.

      Although some can cause serious food poisoning, most serotypes are harmless.

      Escherichia coli is transmitted via the faeco-oral route.

    • This question is part of the following fields:

      • Microbiology
      • Specific Pathogen Groups
      21.1
      Seconds
  • Question 67 - In the emergency room, a patient was diagnosed with acute bacterial tonsillitis. Which...

    Incorrect

    • In the emergency room, a patient was diagnosed with acute bacterial tonsillitis. Which of the following postinfectious complications is most commonly linked to Streptococcus pyogenes:

      Your Answer: Subacute sclerosing panencephalitis

      Correct Answer: Glomerulonephritis

      Explanation:

      Poststreptococcal glomerulonephritis (PSGN) is caused by prior infection with specific nephritogenic strains of group A beta-haemolytic streptococcus. The clinical presentation of PSGN varies from asymptomatic, microscopic haematuria to the full-blown acute nephritic syndrome, characterized by red to brown urine, proteinuria (which can reach the nephrotic range), oedema, hypertension, and acute kidney injury.

    • This question is part of the following fields:

      • Microbiology
      • Pathogens
      59.8
      Seconds
  • Question 68 - Regarding ciprofloxacin, which of the following statements is INCORRECT: ...

    Correct

    • Regarding ciprofloxacin, which of the following statements is INCORRECT:

      Your Answer: Ciprofloxacin decreases plasma concentrations of theophylline.

      Explanation:

      Ciprofloxacin increases plasma concentrations of theophylline. There is an increased risk of convulsions when quinolones are given with NSAIDs or theophylline. There is an increased risk of tendon damage when quinolones are given with corticosteroids. Quinolones are known to increase the QT-interval and should not be taken with concomitantly with other drugs that are known to cause QT-interval prolongation. There is an increased risk of myopathy when erythromycin or clarithromycin are taken with simvastatin or atorvastatin.

    • This question is part of the following fields:

      • Infections
      • Pharmacology
      15.5
      Seconds
  • Question 69 - Which of the following microbes produces exotoxin: ...

    Correct

    • Which of the following microbes produces exotoxin:

      Your Answer: Clostridium tetani

      Explanation:

      Clostridium tetani (causing tetanus) produces the exotoxin tetanospasmin which causes its neurotoxic effects.

    • This question is part of the following fields:

      • Microbiology
      • Principles
      13.6
      Seconds
  • Question 70 - Regarding the penis, which of the following statements is CORRECT: ...

    Incorrect

    • Regarding the penis, which of the following statements is CORRECT:

      Your Answer: Sensation to the penis is supplied by the genital branch of the genitofemoral nerve.

      Correct Answer: The corpus spongiosum is ventral in the erect penis.

      Explanation:

      Because the anatomical position of the penis is erect, the paired corpora cavernosa are defined as dorsal in the body of the penis and the single corpus spongiosum as ventral. The nerves and vessels lie superficial to the corpus cavernosum. The urethra lies within the corpus spongiosum.

    • This question is part of the following fields:

      • Abdomen
      • Anatomy
      31
      Seconds
  • Question 71 - A well recognised adverse effect of metoclopramide is which of the following? ...

    Correct

    • A well recognised adverse effect of metoclopramide is which of the following?

      Your Answer: Acute dystonic reaction

      Explanation:

      Side effects of metoclopramide are commonly associated with extrapyramidal effects and hyperprolactinemia. Therefore its use must be limited to short-term use. Metoclopramide can induce acute dystonic reactions which involve facial and skeletal muscle spasms and oculogyric crises. These dystonic effects are more common in the young girls and young women, and in the very old. These symptoms usually occur shortly after starting treatment with this drug and subside within 24 hours of stopping it. Abortion of dystonic attacks can be carried out by injection of an antiparkinsonian drug like procyclidine.

    • This question is part of the following fields:

      • Central Nervous System
      • Pharmacology
      7.2
      Seconds
  • Question 72 - Regarding the varicella zoster virus, which of the following statements is CORRECT: ...

    Incorrect

    • Regarding the varicella zoster virus, which of the following statements is CORRECT:

      Your Answer: The varicella zoster vaccine is part of routine childhood immunisation.

      Correct Answer: Contracting chickenpox infection while pregnant is associated with a higher risk of developing varicella pneumonitis.

      Explanation:

      Chickenpox infection in neonates, adults/adolescents and pregnant women is associated with more severe disease. Varicella zoster pneumonitis typically occurs in pregnant women or immunocompromised individuals and is associated with a high mortality. A live attenuated-virus vaccine is available and recommended for non-immune healthcare workers but is not part of the routine childhood immunisation schedule. Antiviral treatment is not typically recommended in childhood chickenpox but is indicated for shingles.

    • This question is part of the following fields:

      • Microbiology
      • Pathogens
      24.9
      Seconds
  • Question 73 - A 4-year-old girl is rushed to the Emergency Department by her grandparents after...

    Correct

    • A 4-year-old girl is rushed to the Emergency Department by her grandparents after swallowing some of her grandfather's Warfarin tablets. On further questioning, it turns out that she took 5 of his 3 mg tablets which he needs to take due to a history of atrial fibrillation. The child appears healthy well-oriented in time, place and person, and has normal vitals.

      What is the threshold dose of Warfarin that needs to be ingested for there to be a risk of anticoagulation?

      Your Answer: 0.5 mg/kg

      Explanation:

      The clinical effects of Warfarin occur after a dose of greater than 0.5 mg/kg, and they will be observable 8-10 hours after consumption of the drug. The antidote used for Warfarin is Vitamin K.

      1. In low-risk cases with no apparent bleeding:
      an oral dose of 10 mg vitamin K

      2. If there is clinically significant bleeding
      an intravenous dose of 250-300 mcg/kg

      Activated charcoal:
      in cases of warfarin ingestion
      binds to it and reduces the absorption of warfarin
      the ingestion must have occurred within the last hour
      There is, however, rarely a need for the use of activated charcoal because vitamin K is such as safe and effective antidote.

      Clotting studies, including an INR, can be performed, but small children who have ingested warfarin do not require INRs or follow up if they have been treated with 10 mg vitamin K. This dose of vitamin will completely reverse the anticoagulative effects of warfarin.

      Perform INR if any of the following are present:
      1. Delayed presentation (>6 hours)
      2. Patients with symptoms or signs of anticoagulation
      3. Possible massive ingestion

    • This question is part of the following fields:

      • Cardiovascular Pharmacology
      • Pharmacology
      13.3
      Seconds
  • Question 74 - Dehydration causes a significant increase in the amount of this hormone? ...

    Correct

    • Dehydration causes a significant increase in the amount of this hormone?

      Your Answer: Antidiuretic hormone

      Explanation:

      Antidiuretic hormone induces the kidneys to release less water, resulting in reduced urine production.

      In the case of dehydration, ADH levels rise, resulting in a considerable decrease in urine output as well as an increase in plasma protein, blood Hct, and serum osmolality.

    • This question is part of the following fields:

      • Endocrine
      • Physiology
      4.9
      Seconds
  • Question 75 - Cryptococcus neoformans is primarily implicated in which of the following conditions: ...

    Incorrect

    • Cryptococcus neoformans is primarily implicated in which of the following conditions:

      Your Answer: Catheter associated UTI

      Correct Answer: Chronic lymphocytic meningitis

      Explanation:

      Cryptococcus neoformans typically causes a chronic lymphocytic meningitis in immunosuppressed patients or those with intense exposure e.g. pigeon fanciers.

    • This question is part of the following fields:

      • Microbiology
      • Pathogens
      10
      Seconds
  • Question 76 - You are prescribing ipratropium bromide for a patient who has presented with an...

    Incorrect

    • You are prescribing ipratropium bromide for a patient who has presented with an exacerbation of her COPD. What is the mechanism of action of ipratropium bromide:

      Your Answer: Muscarinic agonist

      Correct Answer: Muscarinic antagonist

      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
      16.3
      Seconds
  • Question 77 - An 80-year-old woman with history of hypertension, diabetes, and ischemic stroke, presents with...

    Incorrect

    • An 80-year-old woman with history of hypertension, diabetes, and ischemic stroke, presents with left-sided hemiplegia of the face, tongue, and limbs and right-sided deficits in motor eye activity. A CT scan was ordered and showed a right-sided stroke.

      Branches of which of the following arteries are most likely implicated in the case?

      Your Answer: Vertebral artery

      Correct Answer: Basilar artery

      Explanation:

      Weber syndrome is a midbrain stroke characterized by crossed hemiplegia along with oculomotor nerve deficits and it occurs with the occlusion of the median and/or paramedian perforating branches of the basilar artery.

      Typical clinical findings include ipsilateral CN III palsy, ptosis, and mydriasis (such as damage to parasympathetic fibres of CN III) with contralateral hemiplegia.

    • This question is part of the following fields:

      • Anatomy
      • Central Nervous System
      34.9
      Seconds
  • Question 78 - Regarding saliva, which of the following statements is CORRECT: ...

    Incorrect

    • Regarding saliva, which of the following statements is CORRECT:

      Your Answer: At rest, saliva is predominantly produced by the parotid gland.

      Correct Answer: Saliva production is decreased by inhibition of the parasympathetic nervous system.

      Explanation:

      At rest, saliva is predominantly produced by the submandibular gland (65%) but when stimulated, the parotid glands produce a higher proportion of the total saliva production (50%) than at rest. Saliva is alkaline and hypotonic to plasma. The predominant digestive enzymes in saliva are alpha-amylase and lingual lipase; lingual lipase is not functionally very important, but alpha-amylase is important for the initiation of starch digestion. Saliva production is decreased by inhibition of the parasympathetic nervous system e.g. by sleep, dehydration, anticholinergic drugs and fear.

    • This question is part of the following fields:

      • Gastrointestinal
      • Physiology
      13.9
      Seconds
  • Question 79 - A 21-year-old student presents to the minors area of your Emergency Department with...

    Correct

    • A 21-year-old student presents to the minors area of your Emergency Department with a laceration on his external nose that occurred during sparring in a kickboxing class. The area is bleeding profusely and will require suturing. Pressure is being applied. The laceration extends through some of the nasal muscles.
      Motor innervation of the nasal muscles of facial expression is provided by which of the following ? Select ONE answer only.

      Your Answer: Facial nerve

      Explanation:

      The facial nerve (the labyrinthine segment) is the seventh cranial nerve, or simply CN VII. It emerges from the pons of the brainstem, controls the muscles of facial expression, and functions in the conveyance of taste sensations from the anterior two-thirds of the tongue.
      Motor innervation of the nasal muscles of facial expression is provided by the facial nerve (CN VII).

    • This question is part of the following fields:

      • Anatomy
      • Head And Neck
      8.5
      Seconds
  • Question 80 - A 53-year-old male has presented to your clinic with the complaint of a...

    Correct

    • A 53-year-old male has presented to your clinic with the complaint of a rash on his right forearm. On examination, you discover small reddish-purple spots on the skin measuring less than 2-3 mm. They do not blanch on applying pressure.

      Which one of the following best fits the description given above?

      Your Answer: Petechiae

      Explanation:

      Petechiae are small red or purple spots on the skin measuring less than 3 mm, caused by minor haemorrhages which do not blanch on applying pressure.
      Purpura measures between 3mm and 1 cm in diameter, while ecchymoses are greater than 1 cm in diameter. Both are caused due to haemorrhage.

      Erythema is the generalised redness of the skin.

      A macule is a flat, discoloured area of the skin measuring less than 1 cm in diameter.

    • This question is part of the following fields:

      • General Pathology
      • Pathology
      18.6
      Seconds
  • Question 81 - Your consultant requests that you do a lumbar puncture on a patient who...

    Correct

    • Your consultant requests that you do a lumbar puncture on a patient who is suspected of having meningitis. This patient, a 15-year-old female, presented to the emergency department with a fever, headache, and neck stiffness. Where should you aspirate a sample of CSF?

      Your Answer: Subarachnoid space

      Explanation:

      A lumbar puncture, also known as a spinal tap, is a procedure that involves inserting a needle into the lower back’s lumbar region.

      A needle is inserted into the space between the arachnoid mater and the pia mater, also known as the subarachnoid space, to remove a sample of cerebrospinal fluid.

    • This question is part of the following fields:

      • Anatomy
      • Head And Neck
      17.6
      Seconds
  • Question 82 - The correct statement regarding the parasympathetic nervous system is which of the following?...

    Incorrect

    • The correct statement regarding the parasympathetic nervous system is which of the following?

      Your Answer: Parasympathetic preganglionic neurones release acetylcholine which acts on cholinergic muscarinic receptors.

      Correct Answer: Parasympathetic preganglionic neurones run in cranial nerves III, VII, IX and X.

      Explanation:

      The electron transfer system is responsible for most of the energy produced during respiration. The is a system of hydrogen carriers located in the inner mitochondrial membrane. Hydrogen is transferred to the electron transfer system via the NADH2 molecules produced during glycolysis and the Krebs cycle. As a result, a H+ion gradient is generated across the inner membrane which drives ATP synthase. The final hydrogen acceptor is oxygen and the H+ions and O2 combine to form water.

    • This question is part of the following fields:

      • Basic Cellular
      • Physiology
      41.9
      Seconds
  • Question 83 - Which of the following is NOT a notifiable disease: ...

    Incorrect

    • Which of the following is NOT a notifiable disease:

      Your Answer: Tuberculosis

      Correct Answer: Chickenpox

      Explanation:

      Chickenpox is not a notifiable disease.

    • This question is part of the following fields:

      • Infections
      • Pharmacology
      9.6
      Seconds
  • Question 84 - Gallstones are commonly found lodged in which of the following parts of the...

    Correct

    • Gallstones are commonly found lodged in which of the following parts of the gallbladder?

      Your Answer: Neck

      Explanation:

      There is a significant association between the presence of Hartmann’s pouch and gallbladder stones. It is the most common location for gallstones to become lodged and cause cholestasis.

    • This question is part of the following fields:

      • Abdomen And Pelvis
      • Anatomy
      8.8
      Seconds
  • Question 85 - A 30 year old man presents to ED after a road traffic accident....

    Correct

    • A 30 year old man presents to ED after a road traffic accident. Free intraperitoneal fluid is found on FAST (Focussed assessment for sonography in trauma) done in the supine position.

      Which of these is most likely to be affected?

      Your Answer: Hepatorenal recess

      Explanation:

      Fluid accumulates most often in the hepatorenal pouch (of Morrison) in a supine patient. The hepatorenal pouch is located behind the liver and anterior to the right kidney and is the lowest space in the peritoneal cavity in the supine position.

      Although the vesicouterine and rectouterine spaces are also potential spaces for fluid accumulation, fluid accumulation in them occur in the erect position.

    • This question is part of the following fields:

      • Abdomen
      • Anatomy
      16.3
      Seconds
  • Question 86 - Which of the following muscles is most responsible for thigh extension at the...

    Incorrect

    • Which of the following muscles is most responsible for thigh extension at the hip joint?

      Your Answer: Quadriceps femoris, gluteus medius and gluteus minimus

      Correct Answer: Hamstrings and gluteus maximus

      Explanation:

      For hip extension, the gluteus maximus and hamstring muscles work together. To compensate for gluteus maximus weakness, the hamstring frequently acts as the primary hip extensor.

    • This question is part of the following fields:

      • Anatomy
      • Lower Limb
      21.2
      Seconds
  • Question 87 - The following statements concerning lung compliance is true EXCEPT?
    ...

    Incorrect

    • The following statements concerning lung compliance is true EXCEPT?

      Your Answer: Lung compliance is inversely proportional to stiffness and elastance

      Correct Answer: Lung compliance is described by the equation: C = ∆ P/ ∆V, where C = compliance, P = pressure, and V = volume

      Explanation:

      Lung compliance is the change in volume per unit change in distending pressure.

      It is calculated using the equation:
      Lung compliance = ΔV / ΔP
      Where:
      ΔV is the change in volume
      ΔP is the change in pleural pressure.

      Lung compliance is inversely proportional to stiffness and elastance.

      It comprises static (no airflow) and dynamic (during continuous breathing) components.

      It is the slope of the pressure-volume curve.

      Lung compliance describes the distensibility of the lungs and the chest wall.

    • This question is part of the following fields:

      • Physiology
      • Respiratory Physiology
      31.5
      Seconds
  • Question 88 - A 57-year-old male presents to the orthopaedic clinic complaining of pain and swelling...

    Correct

    • A 57-year-old male presents to the orthopaedic clinic complaining of pain and swelling in the left knee joint. On examination, the left knee is swollen, tender and erythematous. The patient is booked for joint aspiration, and a diagnosis of pseudogout is made following the aspiration.

      Which types of crystals would be seen in the joint aspirate to lead to this diagnosis?

      Your Answer: Positively birefringent 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.

    • This question is part of the following fields:

      • General Pathology
      • Pathology
      19.3
      Seconds
  • Question 89 - A 40-year-old man who has a history of asthma arrives at the emergency...

    Correct

    • A 40-year-old man who has a history of asthma arrives at the emergency department complaining of palpitations that have been going on for 5 days. Which of the following beta-blockers is the safest for an asthmatic patient?

      Your Answer: Atenolol

      Explanation:

      Atenolol is a beta blocker, which is a type of medication that works by preventing certain natural substances in the body, such as epinephrine, from acting on the heart and blood vessels.

      This effect reduces heart rate, blood pressure, and cardiac strain. Atenolol, bisoprolol fumarate, metoprolol tartrate, nebivolol, and (to a lesser extent) acebutolol have a lower action on beta2 (bronchial) receptors and are thus cardio selective but not cardiac specific.

      They have a lower effect on airway resistance, although they are not without this adverse effect.

    • This question is part of the following fields:

      • Cardiovascular
      • Pharmacology
      9.1
      Seconds
  • Question 90 - Which of the following occurs at the transverse thoracic plane: ...

    Correct

    • Which of the following occurs at the transverse thoracic plane:

      Your Answer: Bifurcation of the trachea

      Explanation:

      A way to help remember the structures transected by the transverse thoracic plane is CLAPTRAP:
      C: cardiac plexus
      L: ligamentum arteriosum
      A: aortic arch (inner concavity)
      P: pulmonary trunk
      T: tracheal bifurcation (carina)
      R: right-to-left movement of the thoracic duct (posterior to the oesophagus)
      A: azygos vein drains into superior vena cava
      P: pre-vertebral fascia and pre-tracheal fascia end

    • This question is part of the following fields:

      • Anatomy
      • Thorax
      14.2
      Seconds
  • Question 91 - Which of the following is NOT an indication for a H1 receptor antihistamine:...

    Correct

    • Which of the following is NOT an indication for a H1 receptor antihistamine:

      Your Answer: Gastroesophageal reflux disease

      Explanation:

      Antihistamines are competitive inhibitors at the H1-receptor (in contrast to H2 receptor antagonists used to decrease gastric acid secretion in gastroesophageal reflux disease).
      Indications:
      Allergic rhinitis and conjunctivitis
      Urticarial rashes, pruritus, insect bites and stings
      Angioedema
      Anaphylaxis (second line adjunct to adrenaline)
      Nausea/vomiting and prevention of motion sickness
      Insomnia

    • This question is part of the following fields:

      • Pharmacology
      • Respiratory
      18.5
      Seconds
  • Question 92 - A study investigating the risk of suffering a stroke in patients with atrial...

    Incorrect

    • A study investigating the risk of suffering a stroke in patients with atrial fibrillation taking the new antiplatelet drug ticagrelor, compared with standard treatment with warfarin is done over a 2-year time period. 30 of the 300 patients taking ticagrelor and 20 of the 500 patients taking warfarin suffered a stroke over the 2-year period.

      One of these statements is true regarding the outcomes of this study.

      Your Answer: The relative risk is 0.4

      Correct Answer: Ticagrelor increases the risk of stroke

      Explanation:

      Absolute risk and relative risk are used to assess the strength of a relationship between a disease and a factor that may affect it.

      Absolute risk (AR) is the risk of developing a disease over a time period:
      AR = the number of events that occur in a group / number of people in that group

      The absolute risk reduction (ARR) is the difference between the absolute risk in the control group (ARC) and the absolute risk in the treated group (ART).

      ARR = ARC – ART

      The control group is the warfarin group, therefore the ARC is 20/500 (0.04).
      Treatment group is the ticagrelor group and ART = 30/300 (0.1).

      ARR = 0.04 – 0.1 = -0.06. This shows that treatment with ticagrelor increases risk of developing stroke. This is also termed a relative risk increase.

      Relative risk, or risk ratio, (RR) is used to compare the risk in the two different groups. It is the ratio of the absolute risks of the disease in the treatment group (ART) to the absolute risk of the disease in the control group (ARC):
      RR=ART /ARC

      Therefore RR = 0.1 / 0.04 = 2.5
      RR < 1 means the intervention reduces the risk of the outcome being studied
      RR = 1 means the treatment has no effect on the outcome being studied
      RR > 1 means the intervention increased the risk of the outcome being studied
      Since RR is 2.5, ticagrelor increases the risk of stroke.

      SUMMARY
      Absolute risk reduction is -0.06
      Absolute risk in warfarin group = 0.04
      Relative risk = 2.5
      Ticagrelor has no effect on stroke is incorrect because RR is not =1

    • This question is part of the following fields:

      • Evidence Based Medicine
      31.8
      Seconds
  • Question 93 - A 26-year-old athlete presents with buttock pain after tearing his gluteus maximus muscle.
    Which...

    Incorrect

    • A 26-year-old athlete presents with buttock pain after tearing his gluteus maximus muscle.
      Which of the following is NOT an action of the gluteus maximus muscle? Select ONE answer only.

      Your Answer: Hip extension

      Correct Answer: Hip abduction

      Explanation:

      Gluteus maximus is the main extensor muscle of the hip and assists with lateral rotation of the thigh at the hip joint. It also acts as a hip adductor, steadies the thigh, and assists in raising the trunk from a flexed position.
      Gluteus maximus is innervated by the inferior gluteal nerve.

    • This question is part of the following fields:

      • Anatomy
      • Lower Limb
      17.6
      Seconds
  • Question 94 - Which of the following muscles is least likely to be involved in forceful expiration:...

    Incorrect

    • Which of the following muscles is least likely to be involved in forceful expiration:

      Your Answer: Internal intercostal muscles

      Correct Answer: External intercostal muscles

      Explanation:

      Forceful expiration is primarily produced by the deeper thoracic muscles (internal and innermost intercostal muscles, subcostals and transversus thoracis) aided by contraction of the abdominal wall muscles which increase intra-abdominal pressure thus further reducing the volume of the thorax.

    • This question is part of the following fields:

      • Anatomy
      • Thorax
      20.8
      Seconds
  • Question 95 - A 65-year-old man presents with cough and shortness of breath. His sputum is...

    Incorrect

    • A 65-year-old man presents with cough and shortness of breath. His sputum is rusty in colour and is suffering from a fever. Upon examination, it was noted that he has crackles in the right upper lobe. A chest X-ray showed the presence of a right upper lobe cavitation.

      Among the following microorganisms, which is considered to be mostly associated with a cavitating upper lobe pneumonia?

      Your Answer: Haemophilus influenzae

      Correct Answer: Klebsiella pneumoniae

      Explanation:

      Klebsiella pneumoniae is among the most common Gram-negative bacteria encountered by physicians worldwide and accounts for 0.5-5.0% of all cases of pneumonia. This organism can cause extensive pulmonary necrosis and frequent cavitation.

      It is one of the causes that could be suspected when there is cavitatory pneumonia with or without a bulging fissure sign. Often, there can be extensive lobar opacification with air bronchograms.

      A helpful feature which may help to distinguish from pneumococcal pneumonia is that Klebsiella pneumoniae develops cavitation in 30-50% of cases (in comparison, cavitation is rare in pneumococcal pneumonia). This occurs early and progresses quickly.

    • This question is part of the following fields:

      • Microbiology
      • Specific Pathogen Groups
      19
      Seconds
  • Question 96 - A GP is considering prescribing a non-steroidal anti-inflammatory (NSAID) for pain relief for...

    Incorrect

    • A GP is considering prescribing a non-steroidal anti-inflammatory (NSAID) for pain relief for a patient with a knee injury

      Which of these statements about NSAIDs is NOT true?

      Your Answer: Most NSAIDs act as non-selective inhibitors of the enzyme cyclo-oxygenase

      Correct Answer: Side effects are less commonly seen with indomethacin than naproxen

      Explanation:

      Most NSAIDs act as non-selective inhibitors of the enzyme cyclo-oxygenase (COX). They inhibit both COX-1 and COX-2 isoenzymes.

      Only about 60% of patients will respond to any given NSAID.

      It can take 21 days of treatment for a clinically appreciable reduction in inflammation to be apparent. If no improvement is seen after 21 days, the NSAID should be changed.

      The use of NSAIDs in the 3rd trimester of pregnancy is associated with the following risks: delayed onset of labour, premature closure of ductus arteriosus and foetal kernicterus.

      Side effects are lowest in Ibuprofen and highest in indomethacin. so side effects are more commonly seen with indomethacin than naproxen.

    • This question is part of the following fields:

      • Musculoskeletal Pharmacology
      • Pharmacology
      27.5
      Seconds
  • Question 97 - Renin is produced by which of the following: ...

    Incorrect

    • Renin is produced by which of the following:

      Your Answer: The macula densa

      Correct Answer: Granular cells in the wall of the afferent arteriole

      Explanation:

      Juxtaglomerular cells are specialised smooth muscle cells mainly in the walls of the afferent arterioles (and some in the efferent arterioles) which synthesise renin.

    • This question is part of the following fields:

      • Physiology
      • Renal
      10.3
      Seconds
  • Question 98 - A 66-year-old male is brought to your clinic by his wife with the...

    Correct

    • A 66-year-old male is brought to your clinic by his wife with the complaint of increasing confusion and disorientation over the past three days, along with decreased urination. She reports that he has been complaining of increasing pain in his back and ribs over the past three months.

      On examination, the patient looks anaemic, is not oriented in time, place and person and has tenderness on palpation of the lumbar spine and the 10th, 11th and 12th ribs.

      Blood tests show anaemia which is normocytic, normochromic, raised urea and creatinine and hypercalcemia.

      Which one of the following diagnoses is most likely in this case?

      Your Answer: Multiple myeloma

      Explanation:

      Multiple myeloma is a clonal abnormality affecting plasma cells in which there is an overproduction of functionless immunoglobulins. The most common patient complaint is bone pain, especially in the back and ribs. Anaemia and renal failure are common, along with hypercalcemia. Hypercalcemia may lead to an altered mental status, as in this case.

      Chronic lymphocytic leukaemia occurs due to the overproduction of lymphocytes, usually B cells. CLL may present with an asymptomatic elevation of B cells. Patients are generally more than 50 years old and present with non-specific fatigue and weight loss symptoms.

      There is no history of alcohol abuse in this case. Furthermore, patients with a history of alcohol abuse may have signs of liver failure, which are not present here.

      Metastatic prostate cancer would most often cause lower backache as it metastasises first to the lumbar spine via the vertebral venous plexus.

      A patient with Vitamin B12 deficiency would have anaemia, megaloblastic, hypersegmented neutrophils, and signs of peripheral neuropathy.

    • This question is part of the following fields:

      • Haematology
      • Pathology
      41.9
      Seconds
  • Question 99 - An elderly female has a bacterial infection and you are asked to prescribe...

    Incorrect

    • An elderly female has a bacterial infection and you are asked to prescribe an antibiotic to her. This antibiotic is a nucleic acid synthesis inhibitor.

      Which of the following antimicrobial drugs will be prescribed to this patient?

      Your Answer: Gentamicin

      Correct Answer: Metronidazole

      Explanation:

      Metronidazole and the other 5-nitroimidazole agents inhibit nucleic acid synthesis by forming toxic free radical metabolites in the bacterial cell that damage DNA.

      Vancomycin inhibits cell wall peptidoglycan formation by binding the D-Ala-D-Ala portion of cell wall precursors.

      Erythromycin inhibits protein synthesis and blocks translocation by binding to the 23S rRNA of the 50S ribosomal subunit.

      Chloramphenicol blocks peptidyl transferase at 50S ribosomal subunit.

      Gentamicin, an aminoglycoside antibiotic, acts by binding to the 30S subunit of the bacterial ribosome inhibiting the binding of aminoacyl-tRNA and thus preventing initiation of protein synthesis.

      An overview of the different mechanisms of action of the various types of antimicrobial agents is shown below:
      1. Inhibition of cell wall synthesis
      – Penicillins
      – Cephalosporins
      – Vancomycin
      2. Disruption of cell membrane function
      – Polymyxins
      – Nystatin
      – Amphotericin B
      3. Inhibition of protein synthesis
      – Macrolides
      – Aminoglycosides
      – Tetracyclines
      – Chloramphenicol
      4. Inhibition of nucleic acid synthesis
      – Quinolones
      – Trimethoprim
      – 5-nitroimidazoles
      – Rifampicin
      5. Anti-metabolic activity
      – Sulphonamides
      – Isoniazid

    • This question is part of the following fields:

      • Infections
      • Pharmacology
      10.7
      Seconds
  • Question 100 - An unrelated medical condition brings a 28-year-old asthmatic man to the Emergency Department....

    Correct

    • An unrelated medical condition brings a 28-year-old asthmatic man to the Emergency Department. When you look over his meds, you notice that he is taking Theophylline to help with his asthma.

      Which of the following medicines should you NOT prescribe?

      Your Answer: Ciprofloxacin

      Explanation:

      Ciprofloxacin is a cytochrome P450 enzyme inhibitor that raises theophylline levels in the blood. As a result, co-prescribing theophylline should be avoided.

      The medicines that typically impact theophylline’s half-life and plasma concentration are listed in the table below:
      Drugs that increase the levels of theophylline in the blood
      Drugs that lower theophylline levels in the blood
      Calcium channel blockers e.g. Verapamil
      Fluconazole
      Cimetidine
      Quinolones, e.g. ciprofloxacin
      Methotrexate
      Barbiturates
      Carbamazepine
      Phenobarbital
      Macrolides, e.g. erythromycin
      Phenytoin (and fosphenytoin)
      Rifampicin
      St. John’s wort

    • This question is part of the following fields:

      • Pharmacology
      • Respiratory Pharmacology
      16.8
      Seconds

SESSION STATS - PERFORMANCE PER SPECIALTY

Pharmacology (17/32) 53%
Respiratory Pharmacology (2/3) 67%
Endocrine Physiology (1/2) 50%
Physiology (7/18) 39%
Infections (4/8) 50%
Central Nervous System (7/10) 70%
Anatomy (15/21) 71%
General Pathology (6/6) 100%
Pathology (8/14) 57%
Microbiology (6/12) 50%
Principles (2/2) 100%
Gastrointestinal Physiology (1/1) 100%
Cardiovascular Pharmacology (5/6) 83%
Thorax (3/4) 75%
Pathogens (2/6) 33%
Renal (2/4) 50%
Evidence Based Medicine (2/3) 67%
Respiratory (3/5) 60%
Renal Physiology (1/2) 50%
Haematology (2/6) 33%
CNS Pharmacology (0/2) 0%
Lower Limb (1/4) 25%
Specific Pathogen Groups (1/3) 33%
Upper Limb (3/3) 100%
Cardiovascular (1/3) 33%
Immune Responses (0/1) 0%
Immunoglobulins And Vaccines (0/1) 0%
Basic Cellular (0/2) 0%
Gastrointestinal (1/3) 33%
Endocrine (1/2) 50%
Inflammatory Responses (0/1) 0%
Statistics (1/1) 100%
Abdomen (1/2) 50%
Head And Neck (2/2) 100%
Abdomen And Pelvis (1/1) 100%
Respiratory Physiology (0/1) 0%
Musculoskeletal Pharmacology (0/1) 0%
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