-
Question 1
Correct
-
A 52-year-old patient requires procedural sedation for DC cardioversion of atrial fibrillation. You plan on using propofol as the sedative agent.
Propofol works as a result of action on what type of receptor? Select ONE answer only.Your Answer: Gamma-aminobutyric acid (GABA)
Explanation:Propofol (2,6-diisopropylphenol) is a short-acting phenol derivative that is primarily used for the induction of anaesthesia.
Its mechanism of action is unclear but is thought to act by potentiating the inhibitory neurotransmitters GABA and glycine, which enhances spinal inhibition during anaesthesia.
The dose for induction of anaesthesia is 1.5-2.5mg/kg. The dose for maintenance of anaesthesia is 4-12 mg/kg/hour. Following intravenous injection, propofol acts within 30 seconds and its duration of action is 5-10 minutes.
Propofol produces a 15-25% decrease in blood pressure and systemic vascular resistance without a compensatory increase in heart rate. It is negatively inotropic and decreases cardiac output by approximately 20%.
The main side effects of propofol are:
Pain on injection (in up to 30%)
Hypotension
Transient apnoea
Hyperventilation
Coughing and hiccough
Headache
Thrombosis and phlebitis -
This question is part of the following fields:
- Anaesthesia
- Pharmacology
-
-
Question 2
Incorrect
-
A 22-year-old woman comes in with an asthmatic flare. Salbutamol is her only regular medication.
What is the dosage per inhalation of a standard metered dose salbutamol inhaler?Your Answer: 200 micrograms
Correct Answer: 100 micrograms
Explanation:The dose of a conventional metered dose inhaler is 100 micrograms per metered inhalation.
-
This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
-
-
Question 3
Incorrect
-
Elevation of the eyeball is primarily produced by which of the following muscles:
Your Answer: Superior rectus and superior oblique
Correct Answer: Superior rectus and inferior oblique
Explanation:Elevation of the eyeball is produced by the superior rectus and the inferior oblique muscles.
-
This question is part of the following fields:
- Anatomy
- Head And Neck
-
-
Question 4
Correct
-
A 66-year-old female who is a known case of atrial fibrillation comes to the Emergency Department with the complaint of fever and vomiting for the past two days. When her medical chart is reviewed, you see that she takes Warfarin for her arrhythmia.
Which ONE of the following medications cannot be prescribed to this patient?Your Answer: Ibuprofen
Explanation:Like other non-steroidal anti-inflammatory drugs, Ibuprofen cannot be given with Warfarin as it would increase the bleeding risk of this patient.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 5
Incorrect
-
A 46-year-old male who is suffering from a chest infection. You decide to start giving the patient antibiotics, however he is allergic to penicillin. You consult with one of your co-workers about the best choice of antibiotic to give.
From the following choices, which is considered an example of bacteriostatic antibiotic?
Your Answer: Ceftriaxone
Correct Answer: Trimethoprim
Explanation:Antibiotics that are bactericidal kill bacteria, while antibiotics that are bacteriostatic limit their growth or reproduction. The antibiotics grouped into these two classes are summarized in the table below:
Bactericidal antibiotics
Bacteriostatic antibioticsVancomycin
Metronidazole
Fluoroquinolone, such as ciprofloxacin
Penicillins, such as benzylpenicillin
Cephalosporin, such as ceftriaxone
Co-trimoxazole
Tetracyclines, such as doxycycline
Macrolides, such as erythromycin
Sulphonamides, such as sulfamethoxazole
Clindamycin
Trimethoprim
Chloramphenicol -
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 6
Incorrect
-
Regarding chemical control of respiration, which of the following statements is INCORRECT:
Your Answer: Peripheral chemoreceptors are responsible for about 20% of the ventilatory response to increased PCO2.
Correct Answer: The blood-brain barrier is freely permeable to HCO3 - ions.
Explanation:CSF is separated from the blood by the blood-brain barrier. This barrier is impermeable to polar molecules such as H+and HCO3-but CO2can diffuse across it easily. The pH of CSF is therefore determined by the arterial PCO2and the CSF HCO3-and is not affected by blood pH.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 7
Incorrect
-
The fracture of the medial epicondyle will cause damage to the ulnar nerve. Which of the following motions would be impaired by this type of injury?
Your Answer: Opposition of the thumb
Correct Answer: Adduction of the thumb
Explanation:Fracture of the medial epicondyle is most likely to result in damage to the ulnar nerve.
The three hypothenar muscles, two medial lumbricals, seven interossei, the adductor pollicis, and the deep head of the flexor pollicis brevis are all innervated by the deep branch of the ulnar nerve.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 8
Incorrect
-
After collapsing at home, a 75-year-old man is transported in an ambulance. He is now awake, but he is experiencing palpitations and chest pain. He is transported to resuscitation and placed on a cardiac monitor, which indicates that he is in VT. An amiodarone infusion is set up.
Which of the following statements about amiodarone side effects is correct?Your Answer: It causes shortening of the QT interval
Correct Answer: It can cause jaundice
Explanation:Amiodarone has a lot of potential toxic side effects, so it’s important to get a full clinical evaluation before starting treatment with it.
The following are some of the most common amiodarone side effects:
Arrhythmias
Corneal microdeposits
Hepatic disorders
Hyperthyroidism
Hypothyroidism
Hepatic disorders and jaundice
Nausea
Peripheral neuropathy
Respiratory disorders (including lung fibrosis)
Sleep disturbance
Skin reactions
QT prolongationAmiodarone can cause optic neuritis, which is a very rare side effect. If this happens, the amiodarone should be stopped right away because it poses a risk of blindness.
Most people who take amiodarone develop corneal microdeposits, which go away once the medication is stopped and rarely cause vision problems.
Amiodarone has a chemical structure that is similar to that of thyroxine and can bind to the nuclear thyroid receptor. It can cause both hypothyroidism and hyperthyroidism, though hypothyroidism is far more common, with 5-10% of patients suffering from it.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 9
Incorrect
-
Question 10
Correct
-
Diagnosis of HIV is predominantly made through which of the following:
Your Answer: Antibody detection
Explanation:Diagnosis of HIV is predominantly made through detection of HIV antibody and p24 antigen. Viral load (viral PCR) and CD4 count are used to monitor progression of disease.
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 11
Incorrect
-
All of the following statements are correct with regards to protection of the gastric mucosa except which of the following?
Your Answer: Prostaglandins inhibit acid secretion and enhance mucus and HCO 3 - secretion.
Correct Answer: NSAIDs directly stimulate increased parietal cell acid production.
Explanation:Prostaglandin production, which usually inhibits acid secretion and increases mucus and bicarbonate secretion, is inhibited by NSAIDs.
-
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
-
Question 12
Incorrect
-
Which of the following microbes attaches to host cells by its haemagglutinin antigen:
Your Answer: Haemophilus influenzae
Correct Answer: Influenza virus
Explanation:Hemagglutinin (HA) or Haemagglutinin (BE) is an antigenic glycoprotein found on the surface of the influenza viruses. It is responsible for binding the virus to the cell that is being infected. The name hemagglutinin comes from the protein’s ability to cause red blood cells (erythrocytes) to clump together (agglutinate) in vitro.
-
This question is part of the following fields:
- Microbiology
- Principles
-
-
Question 13
Incorrect
-
A 64-year-old woman had a humerus midshaft fracture due to tripping on a curb and falling on her left arm. She might also have damaged which of the following structures?
Your Answer: Axillary nerve and posterior humeral circumflex artery
Correct Answer: Radial nerve and deep brachial artery
Explanation:The radial nerve and brachial artery are most likely to be damaged in humerus fractures. They are tethered together to the bone and cannot withstand the forces applied to it as a result of the displacement.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 14
Correct
-
A patient presents complaining of visual loss. On examination you note a contralateral homonymous hemianopia. Where is the most likely site of the lesion:
Your Answer: Optic tract
Explanation:At the optic chiasm, fibres from the medial (nasal) half of each retina crossover, forming the right and left optic tracts.
The left optic tract contains fibres from the left lateral (temporal) retina and the right medial retina.
The right optic tract contains fibres from the right lateral retina and the left medial retina.
Each optic tract travels to its corresponding cerebral hemisphere to reach its lateral geniculate nucleus (LGN) located in the thalamus where the fibres synapse.
A lesion of the optic tract will cause a contralateral homonymous hemianopia. -
This question is part of the following fields:
- Anatomy
- Central Nervous System
-
-
Question 15
Incorrect
-
A 39-year-old man who is suffering from a bacterial infection require antibiotic treatment. You need to figure out which antibiotic is most suitable. Listed below are antimicrobial drugs.
Which one is a nucleic acid synthesis inhibitor?
Your Answer: Penicillin G
Correct Answer: Ciprofloxacin
Explanation:Ciprofloxacin and other quinolone antibiotics work by blocking DNA gyrase, an enzyme that compresses bacterial DNA into supercoils, as well as a type II topoisomerase, which is required for bacterial DNA separation. As a result, they prevent nucleic acid synthesis.
The following is a summary of the many modes of action of various types of antimicrobial agents:Action Mechanisms- Examples:
Cell wall production is inhibited
Vancomycin
Vancomycin
CephalosporinsThe function of the cell membrane is disrupted
Nystatin
Polymyxins
Amphotericin BInhibition of protein synthesis
Chloramphenicol
Macrolides
Aminoglycosides
TetracyclinesNucleic acid synthesis inhibition
Quinolones
Trimethoprim
Rifampicin
5-nitroimidazoles
Sulphonamides
Anti-metabolic activity
Isoniazid -
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 16
Incorrect
-
At rest, skeletal muscle accounts for between 15-20% of cardiac output and accounts for around 50% of body weight. This can increase to nearly 80% of cardiac output during exercise. Skeletal muscle circulation is highly controlled and has a number of specialized adaptations as a result of this high degree of disparity during exercise, in combination with the diversity in the size of skeletal muscle around the body.
What is the primary mechanism for boosting skeletal muscle blood flow during exercise?
Your Answer: Capillary angiogenesis
Correct Answer: Metabolic hyperaemia
Explanation:In skeletal muscle, blood flow is closely related to metabolic rate. Due to the contraction of precapillary sphincters, most capillaries are blocked off from the rest of the circulation at rest and are not perfused. This causes an increase in vascular tone and vessel constriction. As metabolic activity rises, this develops redundancy in the system, allowing it to cope with greater demand. During exercise, metabolic hyperaemia, which is induced by the release of K+, CO2, and adenosine, recruits capillaries. Sympathetic vasoconstriction in the active muscles is overridden by this. Simultaneously, blood flow in non-working muscles is restricted, preserving cardiac output. During exercise, muscle contractions pump blood through the venous system, raising the pressure differential between arterioles and venules and boosting blood flow via capillaries.
Capillary angiogenesis is evident when muscles are used repeatedly (e.g. endurance training). It is a long-term effect, not a quick fix for increased blood flow.
The local partial pressure of alveolar oxygen is the primary intrinsic control of pulmonary blood flow (pAO2). Low pAO2 promotes arteriole vasoconstriction and vice versa. The hypoxic pulmonary vasoconstriction (HPV) reflex allows blood flow to be diverted away from poorly ventilated alveoli and towards well-ventilated alveoli in order to maximize gaseous exchange.
-
This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
-
-
Question 17
Correct
-
The most common site of ectopic pregnancy is?
Your Answer: Ampulla of Fallopian tube
Explanation:Nearly 95% of ectopic pregnancies are implanted in the various segments of the fallopian tube and give rise to fimbrial, ampullary, isthmic, or interstitial tubal pregnancies. The ampulla is the most frequent site, followed by the isthmus. The remaining 5% of non tubal ectopic pregnancies implant in the ovary, peritoneal cavity, cervix, or prior caesarean scar.
-
This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
-
-
Question 18
Incorrect
-
An 11-year-old boy was brought to the emergency room due to fever and pain in the ears. Upon physical examination, it was observed that the mastoid area is erythematous and there is a presence of a boggy, tender mass. A diagnosis of acute mastoiditis was made.
Which of the following parts of the temporal bone is most likely involved?Your Answer: Tympanic part
Correct Answer: Petrous part
Explanation:Mastoiditis is the inflammation of a portion of the temporal bone referred to as the mastoid air cells. The mastoid air cells are epithelium lined bone septations that are continuous with the middle ear cavity.
The temporal bone is composed of four parts: the mastoid process, the petrous pyramid, the squamous, and tympanic portions. The mastoid process and the petrous pyramid are the portions of particular interest because of the prevalence of suppurations within these parts of the temporal bone.
-
This question is part of the following fields:
- Anatomy
- Head And Neck
-
-
Question 19
Correct
-
A 29 year old patient with known inflammatory bowel disease presents to ED with surgical complications following his recent ileocaecal resection. Removal of the terminal ileum may result in the malabsorption of which of the following:
Your Answer: Vitamin B12
Explanation:On ingestion, vitamin B12 is bound to R protein found in saliva and gastric secretions, which protects it from digestion in the stomach. Intrinsic factor is secreted by gastric parietal cells. Receptors for the IF-B12 complex are present in the membrane of epithelial cells of the terminal ileum, which bind the complex and allow uptake of vitamin B12 across the apical membrane by endocytosis. Vitamin B12 is then transported across the basal membrane into the portal blood where it is bound to transcobalamin II and processed by the liver. In pernicious anaemia, there are autoantibodies against gastric parietal cells and intrinsic factor, resulting in vitamin B12 deficiency anaemia.
-
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
-
Question 20
Correct
-
Which of the following antibiotics may be used for malaria prophylaxis:
Your Answer: Doxycycline
Explanation:Doxycycline may be used for malaria prophylaxis and as an adjunct to quinine in the treatment of Plasmodium falciparum malaria.
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 21
Incorrect
-
A 30-year-old rugby player suffers from an anterior cruciate ligament tear while pivoting to attempt to run around another player. An MRI was performed and showed that his injury caused two other structures in the knee joint to be injured.
Which of the following structures is most likely also injured?Your Answer: Lateral meniscus
Correct Answer: Medial meniscus
Explanation:The O’Donoghue unhappy triad or terrible triad often occurs in contact and non-contact sports, such as basketball, football, or rugby, when there is a lateral force applied to the knee while the foot is fixated on the ground. This produces an abduction-external rotation mechanism of injury.
The O’Donoghue unhappy triad comprises three types of soft tissue injury that frequently tend to occur simultaneously in knee injuries. O’Donoghue described the injuries as: anterior cruciate ligament tear, medial collateral ligament injury, and medial meniscal tear (lateral compartment bone bruise).
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 22
Incorrect
-
A range of one standard deviation above and below the mean includes what approximate percentage of the sample values:
Your Answer: 0.78
Correct Answer: 0.68
Explanation:A range of one SD above and below the mean (+/- 1 SD) includes 68.2% of the sample values.
A range of two SD above and below the mean (+/- 2 SD) includes 95.4% of the sample values.
A range of three SD above and below the mean (+/- 3 SD) includes 99.7% of the sample values. -
This question is part of the following fields:
- Evidence Based Medicine
- Statistics
-
-
Question 23
Incorrect
-
Which of the following is NOT an effect of gastrin:
Your Answer: Stimulation of pepsinogen release from chief cells
Correct Answer: Stimulation of insulin release
Explanation:Gastrin acts to:
Stimulate acid secretion from parietal cells (both directly and indirectly by stimulating release of histamine from ECL cells)
Stimulate pepsinogen secretion from chief cells
Increase gastric motility
Stimulate growth of gastric mucosa -
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
-
Question 24
Incorrect
-
You are asked to review the blood results on a 56-year-old man who appears to be acutely unwell. His results show that he is neutropenic.
Which ONE of the following is NOT a recognized cause of a neutropenia?Your Answer: Viral infections
Correct Answer: Hyposplenism
Explanation:Neutropenia is defined as a total neutrophil count of < 2.0 x 109/l.
It can be caused by:
Viral infections
Collagen disease e.g. SLE and RA
Chemotherapy and radiotherapy
Hypersplenism
Marrow infiltration
Vitamin and folate deficiency
Drug reactions
Drugs that cause neutropenia include flecainide, phenytoin, carbimazole, indomethacin and co-trimoxazole. -
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 25
Correct
-
A patient presents to ED with heartburn for which they already take regular antacids. Which of the following drugs can be affected if taken with antacids:
Your Answer: Digoxin
Explanation:Antacids should preferably not be taken at the same time as other drugs since they may affect absorption. When antacids are taken with acidic drugs (e.g. digoxin, phenytoin, chlorpromazine, isoniazid) they cause the absorption of the acidic drugs to be decreased, which causes low blood concentrations of the drugs, which ultimately results in reduced effects of the drugs. Antacids taken with drugs such as pseudoephedrine and levodopa increase absorption of the drugs and can cause toxicity/adverse events due to increased blood levels of the drugs. Antacids that contain magnesium trisilicate and magnesium hydroxide when taken with some other medications (such as tetracycline) will bind to the drugs, and reduce their absorption and effects.
-
This question is part of the following fields:
- Gastrointestinal
- Pharmacology
-
-
Question 26
Incorrect
-
A 58-year-old man presented to the emergency room complaining of a chest pain that has been going on for the past 12 hours. Upon further investigation, a troponin test was ordered and the results came back negative. He was given a discharge order from the emergency department.
Which of the following aspects of this test is considered the most significant in the decision made that it was safe to send the patient home?Your Answer: Negative predictive value
Correct Answer: Likelihood ratio
Explanation:The Likelihood Ratio (LR) is the likelihood that a given test result would be expected in a patient with the target disorder compared to the likelihood that that same result would be expected in a patient without the target disorder.
The LR is used to assess how good a diagnostic test is and to help in selecting an appropriate diagnostic tests or sequence of tests. They have advantages over sensitivity and specificity because they are less likely to change with the prevalence of the disorder, they can be calculated for several levels of the symptom/sign or test, they can be used to combine the results of multiple diagnostic test and they can be used to calculate post-test probability for a target disorder.
A LR greater than 1 produces a post-test probability which is higher than the pre-test probability. An LR less than 1 produces a post-test probability which is lower than the pre-test probability. When the pre-test probability lies between 30 and 70 per cent, test results with a very high LR (say, above 10) rule in disease. An LR below 1 produces a post-test probability les than the pre-test probability. A very low LR (say, below 0.1) virtually rules out the chance that the patient has the disease.
-
This question is part of the following fields:
- Evidence Based Medicine
-
-
Question 27
Incorrect
-
A patient diagnosed with cranial nerve palsy exhibits asymmetrical movement of the palate, nasal regurgitation of food, and nasal quality to the voice.
Which of the following cranial nerves is most likely responsible for the aforementioned features?Your Answer: Glossopharyngeal nerve
Correct Answer: Vagus nerve
Explanation:The vagus nerve, ‘the wanderer’, contains motor fibres (to the palate and vocal cords), sensory components (posterior and floor of external acoustic meatus) and visceral afferent and efferent fibres.
Palatal weakness can cause nasal speech and nasal regurgitation of food. The palate moves asymmetrically when the patient says ‘ahh’. Recurrent nerve palsy results in hoarseness, loss of volume and ‘bovine cough’.
-
This question is part of the following fields:
- Anatomy
- Central Nervous System
-
-
Question 28
Incorrect
-
Which of the following statements is correct regarding anti-D immunoglobulin?
Your Answer: It is only administered after sensitising events in rhesus-negative mothers.
Correct Answer: It is administered as part of routine antenatal care for rhesus-negative mothers.
Explanation:In all non-sensitised pregnant women who are RhD-negative, it is recommended that routine antenatal anti-D prophylaxis is offered. Even if there is previous anti-D prophylaxis, use of routine antenatal anti-D prophylaxis should be given for a sensitising event early in the same pregnancy. Postpartum anti-D prophylaxis should also be given even if there has been previous routine antenatal anti-D prophylaxis or antenatal anti-D prophylaxis for a sensitising event in the same pregnancy.
-
This question is part of the following fields:
- Immunoglobulins And Vaccines
- Pharmacology
-
-
Question 29
Incorrect
-
Aside from the inability to extend the leg above the knee, which of the following clinical symptoms should you anticipate seeing in a patient who had a pelvic and right leg injury as well as femoral nerve damage?
Your Answer: Trendelenburg's sign
Correct Answer: Loss of sensation over the anterior thigh
Explanation:The femoral nerve runs down the front of the leg from the pelvis. It gives the front of the thigh and a portion of the lower leg sensation.
Extension of the leg at the knee joint, flexion of the thigh at the hip are produced by muscles that is primarily innervated by the femoral nerve.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 30
Incorrect
-
Regarding water and electrolyte absorption in the small intestine, which of the following statements is INCORRECT:
Your Answer: Na+/K+ ATPase located on the basolateral membrane of the epithelial cells pumps three Na+ ions from the cell in exchange for two K+ ions in.
Correct Answer: Na+ enters the cell across the apical membrane against its concentration gradient by both membrane channels and transporter protein mechanisms.
Explanation:As the contents of the intestine are isotonic with body fluids and mostly have the same concentration of the major electrolytes, their absorption is active. Water cannot be moved directly, but follows osmotic gradients set up by the transport of ions, primarily mediated by the sodium pump.Na+/K+ ATPase located on the basolateral membrane of the epithelial cells pumps three Na+ ions from the cell in exchange for two K+ ions, against their respective concentration gradients. This leads to a low intracellular concentration of Na+ and a high intracellular concentration of K+. The low intracellular concentration of Na+ ensures a movement of Na+ from the intestinal contents into the cell down its concentration gradient by both membrane channels and transporter protein mechanisms. Na+ is then rapidly pumped again by the basolateral sodium pump. K+ leaves the cell across the basolateral membrane down its concentration gradient linked to an outward movement of Cl- against its concentration gradient (Cl- having entered the cell across the luminal membrane down its concentration gradient).
-
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
SESSION STATS - PERFORMANCE PER SPECIALTY
