-
Question 1
Correct
-
What does the correlation coefficient r = 0 indicate with regards to linear relationships between two variables?
Your Answer: There is no correlation between two variables
Explanation:r = 0 if there is no correlation between two variables.
The closer that r is to 0, the weaker the correlation. -
This question is part of the following fields:
- Evidence Based Medicine
- Statistics
-
-
Question 2
Incorrect
-
Bendoflumethiazide may cause all of the following electrolyte imbalances EXCEPT for:
Your Answer: Hypochloraemic alkalosis
Correct Answer: Hypocalcaemia
Explanation:Common side effects of thiazide diuretics include:
Excessive diuresis, postural hypotension, dehydration, renal impairment
Acid-base and electrolyte imbalance
Hypokalaemia, hyponatraemia, hypomagnesaemia, hypercalcaemia, hypochloraemic alkalosis
Metabolic imbalance
Hyperuricaemia and gout
Impaired glucose tolerance and hyperglycaemia
Altered plasma-lipid concentrations
Mild gastrointestinal disturbances -
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 3
Incorrect
-
Which of the following statements about vitamin B12 absorption is TRUE:
Your Answer: Receptors for the vitamin B12/Intrinsic factor complex are found in the duodenum allowing uptake of vitamin B12.
Correct Answer: On ingestion, vitamin B12 is bound to R protein which protects it from digestion in the stomach.
Explanation:The substance intrinsic factor,
essential for absorption of vitamin B12 in the ileum, is
secreted by the parietal cells along with the secretion of
hydrochloric acid. When the acid-producing parietal
cells of the stomach are destroyed, which frequently
occurs in chronic gastritis, the person develops not only
achlorhydria (lack of stomach acid secretion) but often
also pernicious anaemia because of failure of maturation
of the red blood cells in the absence of vitamin B12 stimulation of the bone marrow. -
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
-
Question 4
Incorrect
-
Which of the following statements is correct regarding gentamicin?
Your Answer: Gentamicin is effective against haemolytic streptococci.
Correct Answer: Gentamicin is ineffective against anaerobic bacteria.
Explanation:Gentamicin is the aminoglycoside of choice and is a parenterally administered, broad spectrum antibiotic typically used for moderate to severe gram negative infections. However, it is inactive against anaerobes. There is poor activity against haemolytic streptococci and pneumococci. It is usually given in conjunction with a penicillin or metronidazole (or both) when used for the blind treatment of undiagnosed serious infections. Nephrotoxicity and ototoxicity are the main toxic effects due to damage to the vestibulocochlear nerve (CN VIII).
It is contraindicated in myasthenia gravis and should be used with great care in renal disease as it may result in accumulation and a higher risk of toxic side effects.
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 5
Correct
-
About case-control studies, one of the following is true.
Your Answer: They are suitable to be used in the study of rare diseases
Explanation:Case-control studies are suitable when investigating a rare disease or in cases where little is known about the disease and the proposed aetiological factor, as a preliminary study. They have the ability to look at multiple risk-factors (exposures) but can only look at a single outcome.
In a case-control study, two groups of patients, one with the disease and one without, are compared on the basis of a proposed causative factor that occurred in the past. They are therefore a retrospective study and useful in hypothesis generation.
Cohort studies are better at identifying rare exposures. One group with an exposure is compared to a control group without that exposure.
Case-control studies are usually less expensive to run and also shorter in duration compared with prospective cohort studies.
-
This question is part of the following fields:
- Evidence Based Medicine
-
-
Question 6
Incorrect
-
What is the partial pressure of oxygen if it makes up 20.9 percent of the ambient air composition and the atmospheric pressure of ambient air is 760 mmHg?
Your Answer: 300 mmHg
Correct Answer: 159 mmHg
Explanation:Ambient air is atmospheric air in its natural state. Ambient air is typically 78.6% nitrogen and 20.9% oxygen. The extra 1% is made up of carbon, helium, methane, argon and hydrogen.
The partial pressure of any gas can be calculated using this formula: P = atmospheric pressure (760 mmHg) x percent content in the mixture.
Atmospheric pressure is the sum of all of the partial pressures of the atmospheric gases added together: The formula for atmospheric pressure is: Patm = PN2 + PO2Â + PH2O + PCO2. The atmospheric pressure is known to be 760 mmHg.
The partial pressures of the various gases can be estimated to have partial pressures of approximately 597.4 mmHg for nitrogen, 158.8 mm Hg for oxygen, and 7.6 mmHg for argon.
-
This question is part of the following fields:
- Physiology
- Respiratory Physiology
-
-
Question 7
Incorrect
-
A patient presents with haemoptysis, weight loss, and night sweats. You suspect he may have tuberculosis. He works at an asylum seeker hostel, and has not received a BCG vaccination. In which of the following patient groups would the BCG vaccine be safe to administer?
Your Answer: The patient is HIV positive and asymptomatic
Correct Answer: The patient is asplenic
Explanation:Persons with chronic diseases. Persons with chronic renal disease or undergoing dialysis, and those with hyposplenism or asplenia, may receive BCG vaccine if indicated.
Only 2 absolute contraindications apply to all vaccines:
- anaphylaxis following a previous dose of the relevant vaccine
- anaphylaxis following any component of the relevant vaccine
2 further contraindications apply to live vaccines (both parenteral and oral):
- People who are significantly immunocompromised should not receive live vaccines. This is regardless of whether the immunocompromising condition is caused by disease or treatment.
- Pregnant women should not receive live vaccines, in general. Women should be advised not to become pregnant within 28 days of receiving a live vaccine.
Use of live vaccines in people who are immunocompromised:
People who are immunocomprised are at risk of adverse events or vaccine-related disease if they receive a live vaccine.Live vaccines include:
BCG (bacille Calmette–Guérin) vaccine
oral cholera vaccine (Vaxchora)
Some Japanese encephalitis virus vaccines
MMR (measles-mumps-rubella) vaccine
rotavirus vaccine
oral typhoid vaccine
varicella vaccine
yellow fever vaccine
zoster vaccine (Zostavax) -
This question is part of the following fields:
- Immunological Products & Vaccines
- Pharmacology
-
-
Question 8
Incorrect
-
A 57-year-old woman has presented with cough and shortness of breath. Her GP had done some blood tests recently and told her that she had a positive ANA result.
Which of these statements is true about anti-nuclear antibodies (ANAs)? Select only ONE answer.
Your Answer: Anti-double stranded DNA (Anti-DsDNA) is suggestive of drug-induced lupus.
Correct Answer: The presence of ANAs in rheumatoid arthritis is suggestive of Felty’s syndrome
Explanation:Anti-nuclear antibodies are auto-antibodies directed against a variety of nuclear antigens. There are different staining patterns and each pattern is suggestive of a different disorder.
Speckled staining is suggestive of mixed connective tissue disease.
Nucleolar staining is suggestive of scleroderma, while homogenous staining is suggestive of lupus.
Anti-double stranded DNA is suggestive of SLE while anti-histone antibodies are suggestive of drug-induced lupus.
ELISA testing is cheaper but not the most accurate means of testing for ANAs. Indirect immunofluorescence testing is the most accurate.
The presence of ANAs in rheumatoid arthritis is suggestive of Felty’s syndrome. Felty’s syndrome is characterized by a combination of rheumatoid arthritis, splenomegaly and neutropenia.
-
This question is part of the following fields:
- General Pathology
- Pathology
-
-
Question 9
Incorrect
-
Which of the following pathogens is most likely to cause an infection in a chemo patient with significant neutropenia?
Your Answer: Haemophilus influenzae
Correct Answer: Candida
Explanation:Chemotherapy that is too aggressive weakens your immune system, putting you at risk for a fungal and many other infection.
Neutropenia is a condition in which a person’s neutrophil count is abnormally low. Neutrophils are an infection-fighting type of white blood cell. Neutrophils fight infection by killing bacteria and fungi (yeast) that infiltrate the body.
Fungal organisms are significant pathogens in the setting of neutropenia.
-
This question is part of the following fields:
- Immune Responses
- Pathology
-
-
Question 10
Correct
-
A 47-year-old woman comes in with palpitations that have been bothering her for the past four days. Her haemodynamics are normal, but her heart rate is currently 150 beats per minute. An ECG is performed, which reveals that she is experiencing atrial flutter. The patient is examined by a cardiology registrar, who recommends starting her on verapamil to control her ventricular rate while she waits for cardioversion.
In these circumstances, which of the following is a contraindication to the use of verapamil?Your Answer: Acute porphyria
Explanation:In most cases of atrial flutter, ventricular rate control is used as a stopgap measure until sinus rhythm is restored. A beta-blocker (e.g. bisoprolol), diltiazem, or verapamil can be used to reduce the rate of contractions in the heart.
Electrical cardioversion, pharmacological cardioversion, and catheter ablation can all be used to return the heart to a normal rhythm. Cardioversion should not be attempted until the patient has been fully anticoagulated for at least three weeks if the duration of atrial flutter is unknown or it has lasted longer than 48 hours. Emergency electrical cardioversion is the treatment of choice when there is a sudden onset of symptoms and haemodynamic compromise. For recurrent atrial flutter, catheter ablation is preferred.Verapamil is a calcium-channel blocker that is non-dihydropyridine phenylalkylamine and can be used to treat supraventricular arrhythmias. It’s a calcium channel blocker with a high negative inotropic effect that lowers cardiac output, slows the heart rate, and may impair atrioventricular conduction. At high doses, it can cause heart failure, exacerbate conduction disorders, and cause hypotension.
Adults should take 240-480 mg of verapamil in 2-3 divided doses. 5-10 mg IV over 30 seconds is the corresponding intravenous (IV) dose. After an IV injection, the peak effect lasts 3-5 minutes, and the action lasts 10-20 minutes.
Verapamil should not be taken with beta-blockers like atenolol or quinidine because the combination of their negatively inotropic and negatively chronotropic effects can result in severe hypotension, bradycardia, impaired atrioventricular conduction, heart failure (due to impaired cardiac contractility), and sinus arrest.
The use of verapamil is contraindicated in the following situations:
Acute porphyrias are a type of porphyria that occurs suddenly.
Accessory conducting pathways are linked to atrial flutter or fibrillation (e.g. Wolff-Parkinson-White-syndrome)
Bradycardia
Shock caused by the heart
Insufficiency of the heart (with reduced ejection fraction)
Left ventricular function has been significantly harmed in the past (even if controlled by therapy)
Hypotension (blood pressure less than 90 mmHg)
AV block in the second and third degrees
Sinusitis is a condition in which the sinuses become
Sino-atrial occlusion -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 11
Correct
-
A patient with a central line in situ for the past 10 days now has erythema surrounding the catheter insertion site and shows signs of sepsis. You suspect line sepsis.
Which of these antibacterial agents would be most appropriate to prescribe for this patient?Your Answer: Vancomycin
Explanation:The current recommendation by NICE and the BNF is to use vancomycin as first-line in treatment of septicaemia related to vascular catheter. A broad-spectrum antipseudomonal beta-lactam antibiotic should be added to vancomycin if a Gram-negative sepsis is suspected especially in an immunocompromised patient.
In any patient that has had a central venous catheter in situ for a period longer than a week, it should be suspected as the source of sepsis.
The features suggesting the vascular catheter as the source of infection include:
Presence of the catheter before onset of fever.
The absence of another identifiable source of infection.
Presence of inflammation or purulent material at the insertion site or along the tunnel.
An immunocompetent patient without any underlying disease developing bacteraemia (or fungaemia). -
This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
-
-
Question 12
Incorrect
-
A 35-year-old man presents with haemoptysis, night sweats, and weight loss. Further examinations were done and a diagnosis of tuberculosis is suspected.
Which of the following statements is considered correct regarding Mycobacterium tuberculosis?Your Answer: The Ghon focus typically appears at the base of the lower lobe of the lung
Correct Answer: It is impervious to decolourisation with acid
Explanation:Mycobacterium tuberculosis are part of the Mycobacteriaceae family. They are described to have the characteristics of a Gram-positive cell wall but they are not easily stained with Gram stain. This is because their cell wall contains a high lipid content, and this lipid allows the Mycobacteria to bind to alkaline stains with the application and help of heat. Once stained, they are able to resist decolorization even with the use of acid alcohol as the decolourizer, making them very difficult to decolorize, that is why they are known to be acid-fast.
The Ghon complex is a non-pathognomonic radiographic finding on a chest x-ray that is significant for pulmonary infection of tuberculosis. The location of the Ghon’s focus is usually subpleural and predominantly in the upper part of the lower lobe and lower part of the middle or upper lobe.
Skeletal tuberculosis of the spine is referred to as Pott disease.
The risk of reactivation TB is about 3.3% during the first year after a positive PPD skin test and a total of 5% to 15% thereafter in the person’s lifetime. Progression from infection to active disease varies with age and the intensity and duration of exposure. Reactivation TB occurs when there is an alteration or suppression of the cellular immune system in the infected host that favours
replication of the bacilli and progression to disease. -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 13
Incorrect
-
All of the following statements are incorrect about insulin except:
Your Answer: Insulin release is stimulated initially during eating by the sympathetic nervous system.
Correct Answer: Proinsulin is cleaved into insulin and C peptide.
Explanation:Proinsulin is synthesised as a single-chain peptide. A connecting peptide (C peptide) within storage granules is removed by proteases to yield insulin.
Insulin:
1. is a polypeptide hormone consisting of two short chains (A and B) linked by disulphide bonds.
2. is produced by beta cells, located centrally within the islets of Langerhans, in the endocrine tissues of the pancreas.
3. release is stimulated initially during eating by the parasympathetic nervous system and gut hormones such as secretin. However, most output is driven by the rise in plasma glucose concentration that occurs after a meal.
4. effects are mediated by the receptor tyrosine kinase. -
This question is part of the following fields:
- Endocrine
- Physiology
-
-
Question 14
Incorrect
-
Which of the following statements is false regarding the biceps brachii muscle?
Your Answer:
Correct Answer: It pronates the radioulnar joint in the forearm
Explanation:The biceps brachii muscle is one of the chief muscles of the arm. The origin at the scapula and the insertion into the radius of the biceps brachii means it can act on both the shoulder joint and the elbow joint, which is why this muscle participates in a few movements of the arm. It derives its name from its two heads which merge in one unique distal body, defining the unusual structure of the muscle.
The biceps brachii muscle is supplied by the musculocutaneous nerve (C5-C6), a branch of the brachial plexus.
Arterial supply to the biceps brachii muscle varies considerably, coming from up to eight vessels originating from the brachial artery in the middle third of the arm.
In the shoulder joint both muscle heads partially enforce opposite movements. The long head pulls the arm away from the trunk (abduction) and turns it inwards (inward rotation) whereas the short head pulls the arm back towards the trunk (adduction). When both heads contract simultaneously it leads to an arm bend (flexion). In the elbow joint the muscle bends the forearm (flexion) and rotates it outwards (supination). The supination is most powerful in a flexed elbow. In addition to the movement functions, the biceps has the important task to support the humeral head within the shoulder joint. Its antagonist is the triceps brachii in the posterior compartment of the arm.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 15
Incorrect
-
Monoamine oxidase is primarily involved in the degradation of which of the following:
Your Answer:
Correct Answer: Noradrenaline
Explanation:Catecholamines are broken down extracellularly and in the liver by catechol-O-methyltransferase (COMT) and intracellularly by monoamine oxidase (MAO).
-
This question is part of the following fields:
- Endocrine
- Physiology
-
-
Question 16
Incorrect
-
Which of the following is most likely to cause a homonymous hemianopia:
Your Answer:
Correct Answer: Posterior cerebral artery stroke
Explanation:A posterior cerebral stroke will most likely result in a contralateral homonymous hemianopia with macular sparing.
-
This question is part of the following fields:
- Anatomy
- Central Nervous System
-
-
Question 17
Incorrect
-
A 50-year-old man managed by the renal team for stage 4 chronic kidney disease which appears to be deteriorating presents with a history of shortness of breath and ankle oedema. His most recent blood tests shows low calcium levels.
Which of these increases the renal reabsorption of calcium?Your Answer:
Correct Answer: Parathyroid hormone
Explanation:Parathyroid hormone (PTH), a polypeptide containing 84 amino acids, is the principal hormone that controls free calcium in the body.
Its main actions are:
Increases osteoclastic activity
Increases plasma calcium concentration
Decreases renal phosphate reabsorption
Decreases plasma phosphate concentration
Increases renal tubular reabsorption of calcium
Increases calcium and phosphate absorption in the small intestine
Increases renal conversion of 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
-
-
Question 18
Incorrect
-
A patient suffers a stab wound to the neck. The entry point of the blade is situated within the posterior triangle of the neck.
Which of the following muscles is LEAST likely to be involved? Select ONE answer only.Your Answer:
Correct Answer: Sternohyoid
Explanation:The anterior triangle is the triangular area of the neck found anteriorly to the sternocleidomastoid muscle. It is formed by the anterior border of sternocleidomastoid laterally, the median line of the neck medially and by the inferior border of the mandible superiorly. The apex of the anterior triangle extends towards the manubrium sterni. The anterior triangle contains:
Muscles: thyrohyoid, sternothyroid, sternohyoid muscles
Organs: thyroid gland, parathyroid glands, larynx, trachea, esophagus, submandibular gland, caudal part of the parotid gland
Arteries: superior and inferior thyroid, common carotid, external carotid, internal carotid artery (and sinus), facial, submental, lingual arteries
Veins: anterior jugular veins, internal jugular, common facial, lingual, superior thyroid, middle thyroid veins, facial vein, submental vein, lingual veins
Nerves: vagus nerve (CN X), hypoglossal nerve (CN XII), part of sympathetic trunk, mylohyoid nerveThe posterior triangle is a triangular area found posteriorly to the sternocleidomastoid muscle. It has three borders; anterior, posterior and inferior borders. The anterior border is the posterior margin of the sternocleidomastoid muscle. The posterior border is the anterior margin of the trapezius muscle, while the inferior border is the middle one-third of the clavicle. The investing layer of deep cervical fascia and integument forms the roof of the space, while the floor is covered with the prevertebral fascia along with levator scapulae, splenius capitis and the scalene muscles. The inferior belly of omohyoid subdivides the posterior triangle into a small supraclavicular, and a large occipital, triangle.
Contents:
Vessels: the third part of the subclavian artery, suprascapular and transverse cervical branches of the thyrocervical trunk, external jugular vein, lymph nodes
Nerves: accessory nerve (CN XI), the trunks of the brachial plexus, fibers of the cervical plexus -
This question is part of the following fields:
- Anatomy
- Head And Neck
-
-
Question 19
Incorrect
-
Regarding codeine, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: There is a reduced risk of toxicity in patients who are ultra-rapid metabolisers of codeine.
Explanation:Codeine phosphate is a weak opioid and can be used for the relief of mild to moderate pain where other painkillers such as paracetamol or ibuprofen have proved ineffective.Codeine is metabolised to morphine which is responsible for its therapeutic effects. Codeine 240 mg is approximately equivalent to 30 mg of morphine. The capacity to metabolise codeine can vary considerably between individuals; there is a marked increase in morphine toxicity in people who are ultra rapid metabolisers, and reduced therapeutic effect in poor codeine metabolisers. Codeine is contraindicated in patients of any age who are known to be ultra-rapid metabolisers of codeine (CYP2D6 ultra-rapid metabolisers).Codeine is also contraindicated in children under 12, and in children of any age who undergo the removal of tonsils or adenoids for the treatment of obstructive sleep apnoea due to reports of morphine toxicity.
-
This question is part of the following fields:
- Central Nervous System
- Pharmacology
-
-
Question 20
Incorrect
-
Which of the following statements regarding forest plots is true? Select ONE answer only.
Which of the following statements regarding forest plots is true? Select ONE answer only.Your Answer:
Correct Answer: Larger studies are associated with smaller horizontal lines
Explanation:Forest plots are graphical displays designed to illustrate the relative strength of treatment effects in multiple individual studies addressing the same question.
-
This question is part of the following fields:
- Evidence Based Medicine
-
-
Question 21
Incorrect
-
A 58-year-old male has cellulitis of his left leg. Because he is allergic to penicillin, you start him on erythromycin.
What is erythromycin's mechanism of action?Your Answer:
Correct Answer: Inhibition of protein synthesis
Explanation:Bacteriostatic antibiotics include erythromycin and other macrolide antibiotics. They work by attaching to the bacterial ribosome’s 50S subunit, preventing translocation and thereby protein synthesis. Macrolide antibiotics are actively concentrated inside leukocytes and delivered to the infection site as a result.
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 22
Incorrect
-
Regarding basophils, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: They are the second most common type of granulocyte.
Explanation:Basophils are only occasionally seen in normal peripheral blood comprising < 1% of circulating white cells. However, they are the largest type of granulocyte. They have many dark cytoplasmic granules which overlie the nucleus and contain heparin and histamine. They have immunoglobulin E (IgE) attachment sites and their degranulation is associated with histamine release. Basophils are very similar in both appearance and function to mast cells.
-
This question is part of the following fields:
- Immune Responses
- Pathology
-
-
Question 23
Incorrect
-
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:
Correct 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
-
-
Question 24
Incorrect
-
An analytical cohort study aimed to determine a relationship between intake of dietary calcium and incidence of hip fractures among post-menopausal women. The following are the data obtained from the study:
No. of post-menopausal women who took Calcium: 500
No. of post-menopausal women who took Calcium and suffered a hip fracture: 10
No. of post-menopausal women who took placebo: 500
No. of post-menopausal women who took placebo and suffered a hip fracture: 25
Compute for the risk ratio of a hip fracture.Your Answer:
Correct Answer: 0.4
Explanation:Relative risk (RR) is a ratio of the probability of an event occurring in the exposed group versus the probability of the event occurring in the non-exposed group.
RR can be computed as the absolute risk of events in the treatment group (ART), divided by the absolute risk of events in the control group (ARC).
RR = ART/ARC
RR = (10/500) / (25/500)
RR = 0.4Recall that:
If RR < 1, then the intervention reduces the risk of the outcome.
If RR = 1, then the treatment has no effect on the outcome.
If RR > 1, then the intervention increases the risk of the outcome. -
This question is part of the following fields:
- Evidence Based Medicine
-
-
Question 25
Incorrect
-
Regarding carbon dioxide transport in the blood, which of the following statements is CORRECT:
Your Answer:
Correct 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
-
-
Question 26
Incorrect
-
Regarding the phases of gastric secretion, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: A high pH in the stomach inhibits gastrin secretion.
Explanation:A low pH in the stomach inhibits gastrin secretion, therefore when the stomach is empty or when acid has been secreted for some time after food has entered it, there is inhibition of acid secretion. However, when food first enters the stomach, the pH rises, and this leads to release of the inhibition and causes a maximum secretion of gastrin. Thus gastric acid secretion is self-regulating.
-
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
-
Question 27
Incorrect
-
All of the following statements regarding Helicobacter pylori is considered true, except:
Your Answer:
Correct Answer: Serum antibody levels should be used to check for successful eradication
Explanation:Helicobacter pylori is a curved, non-spore forming, Gram-negative bacteria that is primarily linked to gastric infections. Once acquired, it colonizes the stomach for a long time and can cause a low-grade inflammatory process, producing a chronic superficial gastritis.
H. pylori can be recovered from gastric biopsy materials. Samples must be transported quickly to the laboratory.
Helicobacter infections usually are identified by nonculture methods. H. pylori can be presumptively identified in a gastric biopsy specimen by testing for the presence of a rapid urease reaction.Serologic testing is an important screening method for the diagnosis of H. pylori infection. It can also be diagnosed by faecal antigen detection, microscopic examination of stained gastric tissue, and DNA amplification tests.
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 28
Incorrect
-
A lung function test is being performed on a male patient. For this patient, which of the following volumes for functional residual capacity is considered a normal result?
Your Answer:
Correct Answer: 2.0 L
Explanation:The volume of air that remains in the lungs after a single breath is known as functional residual capacity (FRC). It is calculated by combining the expiratory reserve volume and residual volume. In a 70 kg, average-sized male, a normal functional residual capacity is approximately 2100 mL.
-
This question is part of the following fields:
- Physiology
- Respiratory Physiology
-
-
Question 29
Incorrect
-
A 28-year-old known intravenous drug user has a history of persistent high-fever. On examination you hear a harsh systolic murmur and the patient says a murmur has never been heard before in previous hospital visits. A diagnosis of endocarditis is suspect.
Which of these antibacterial agents would be most appropriate to prescribe in this case?Your Answer:
Correct Answer: Flucloxacillin and gentamicin
Explanation:Endocarditis is infective or non infective inflammation (marantic endocarditis) of the inner layer of the heart and it often involves the heart valves.
Risk factors include:
Prosthetic heart valves
Congenital heart defects
Prior history of endocarditis
Rheumatic fever
Illicit intravenous drug useIn the presentation of endocarditis, the following triad is often quoted:
Persistent fever
Embolic phenomena
New or changing murmurFlucloxacillin and gentamicin are current recommended by NICE and the BNF for the initial ‘blind’ therapy in endocarditis.
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 30
Incorrect
-
Damage to this nerve affects the flexor digitorum longus.
Your Answer:
Correct Answer: Tibial nerve
Explanation:Like all muscles in the deep posterior compartment of the leg, flexor digitorum longus muscle is innervated by branches of the tibial nerve (root value L5, S1 and S2) which is a branch of sciatic nerve.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 31
Incorrect
-
Which of the following could denote a diagnosis of acquired immunodeficiency syndrome (AIDS) in a patient infected with HIV:
Your Answer:
Correct Answer: CD4 count < 200 cells/uL
Explanation:A diagnosis of AIDS can be made in a patient infected with HIV if the patient has a CD4 count < 200 cells/uL, or an AIDS-defining illness. Antiretroviral treatment should be considered in patients with CD4 counts < 350 cells/uL.
Oral candidiasis is not an AIDS defining illness – candidiasis of the bronchi, trachea, lungs or of the oesophagus is an AIDS defining illness.
A positive p24 antigen test seen in early HIV infection and does not indicate the development of AIDS.
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 32
Incorrect
-
You see a 63-year-old man with a history of melaena and epigastric discomfort. For a few months, he's been taking aspirin.
Which of the following statements about aspirin's mechanism of action is correct?Your Answer:
Correct Answer: It inhibits both COX-1 and COX-2 at medium to high doses (500-5000 mg per day)
Explanation:Aspirin inhibits cyclo-oxygenase irreversibly by covalently acetylating the cyclo-oxygenase active site in both COX-1 and COX-2. The production of prostaglandin and thromboxane is reduced as a result. As a result, platelet activation and aggregation are reduced. A single dose of aspirin has a half-life of 7-10 days, which is the time it takes for the bone marrow to produce new platelets.
Aspirin only inhibits COX-1, the enzyme that produces thromboxane A2, at low doses (75 mg per day), and thus has a primarily anti-thrombotic effect.
Aspirin inhibits both COX-1 and COX-2 at medium to high doses (500-5000 mg per day). COX-2 is involved in the production of prostaglandins, so it has an anti-inflammatory effect at these concentrations.
Aspirin, when used as an antipyretic for a viral illness in children, can cause Reye’s syndrome. Reye’s syndrome is a potentially fatal liver disease that causes encephalopathy and liver failure.
The inability of aspirin to reduce platelet production of thromboxane A2, and thus platelet activation and aggregation, is known as aspirin resistance. Although the exact frequency and mechanism of aspirin resistance are unknown, it is thought to affect about 1% of users. Women are more likely than men to experience this phenomenon.
According to new research, taking aspirin on a regular basis lowers the risk of colorectal cancer. It may also protect against cancers of the breast, bladder, prostate, and lungs.
-
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
-
-
Question 33
Incorrect
-
A 36-year-old man who works in a farm presents with a deep laceration over the palm of his hand. A median nerve block was performed at his wrist to facilitate wound exploration and closure.
Which of the following statements regarding median nerve blocks at the wrist is considered correct?Your Answer:
Correct Answer: The needle should be inserted approximately 2.5 cm proximal to flexor retinaculum
Explanation:A median nerve block is a simple, safe, and effective method of obtaining anaesthesia to the palmar aspect of the thumb, index finger, middle finger, radial portion of the palm and ring finger. The median nerve lies deep to the flexor retinaculum and about one centimetre under the skin of the volar wrist.
The palmaris longus tendon lies superficial to the retinaculum and is absent in up to 20% of patients.
The median nerve is located slightly lateral (radial) to the palmaris longus tendon and medial (ulnar) to the flexor carpi radialis tendon.The procedure is as follows:
– Check sensation and motor function of the median nerve. Wear gloves and use appropriate barrier precautions.
– Locate the flexor carpi radialis and palmaris longus tendons, which become prominent when the patient flexes the wrist against resistance. The palmaris longus tendon is usually the more prominent of the two tendons.
– Needle-entry site: The needle will be inserted adjacent to the radial (lateral) border of the palmaris longus tendon just proximal to the proximal wrist crease. If the palmaris longus tendon is absent, the needle-entry site is about 1 cm ulnar to the flexor carpi radialis tendon.
– Cleanse the site with antiseptic solution. Place a skin wheal of anaesthetic, if one is being used, at the needle-entry site.
– Insert the needle perpendicularly through the skin and advance it slowly until a slight pop is felt as the needle penetrates the flexor retinaculum. When paraesthesia in the distribution of the median nerve confirms proper needle placement, withdraw the needle 1 to 2 mm.
– Aspirate to exclude intravascular placement and then slowly (i.e., over 30 to 60 seconds) inject about 3 mL of anaesthetic. If the patient does not feel paraesthesia, redirect the needle in an ulnar direction, under the palmaris longus tendon. If paraesthesia is still not felt, slowly inject 3 to 5 mL of anaesthetic in the proximity of the nerve 1 cm deep to the tendon.
– Allow about 5 to 10 minutes for the anaesthetic to take effect. -
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 34
Incorrect
-
A 34-year-old man presents with loss of vision in his left eye due to an episode of optic neuritis. Upon history taking, it was noted that he has a history of multiple sclerosis.
Which of the following anatomical points in the visual pathway has the lesion occurred?Your Answer:
Correct Answer: Optic nerve
Explanation:A lesion in the optic nerve causes ipsilateral monocular visual loss.
Optic neuritis is an inflammatory demyelination of the optic nerve that is highly associated with multiple sclerosis. The two most common symptoms of optic neuritis are vision loss and eye pain. -
This question is part of the following fields:
- Anatomy
- Central Nervous System
-
-
Question 35
Incorrect
-
A six-year-old boy presents with coryzal symptoms that have persisted for more than two weeks. He was born and raised in the Middle East. His mother claims he has been tired and has complained of various 'aches and pains.' On examination, you find splenomegaly and enlarged cervical lymph nodes. His legs and arms are covered in petechiae.
In this case, what is the most likely diagnosis?Your Answer:
Correct Answer: Acute lymphoblastic leukaemia (ALL)
Explanation:ALL is the most common leukaemia in children, with a peak incidence between the ages of 2 and 5.
ALL has a wide range of clinical symptoms, but many children present with an acute illness that resembles coryza or a viral infection. ALL also has the following features:
Weakness and sluggishness all over
Muscle, joint, and bone pain that isn’t specific
Anaemia
Petechiae and unexplained bruising
Oedema
Lymphadenopathy
HepatosplenomegalyThe following are typical features of a full blood count in patients with ALL:
Anaemia (normocytic or macrocytic)
Leukopenia affects about half of the patients (WCC 4 x 109/l).
Around 25% of patients have leucocytosis (WCC > 10 x 109/l).
Around 25% of patients have hyperleukocytosis (WCC > 50 x 109/l).
Thrombocytopaenia -
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 36
Incorrect
-
Regarding flucloxacillin, which of the following statements is CORRECT:
Your Answer:
Correct Answer: It is resistant to bacterial beta-lactamases.
Explanation:Flucloxacillin is unique in that it is beta-lactamase stable and it can be used in infections caused by beta-lactamase producing staphylococci e.g. S. aureus. It is acid-stable and can therefore be given by mouth as well as by injection. It is used first line for treatment of widespread impetigo infection, cellulitis, mastitis, osteomyelitis, septic arthritis, severe erysipelas, severe/spreading otitis externa and infective endocarditis caused by staphylococci. The most common adverse effects of flucloxacillin include nausea, vomiting, skin rash, and diarrhoea. Cholestatic jaundice and hepatitis may occur very rarely, up to two months after treatment with flucloxacillin has been stopped. Administration for more than 2 weeks and increasing age are risk factors. First line treatment of animal and human bites is co-amoxiclav.
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 37
Incorrect
-
Regarding probability distribution, which of the following statements is CORRECT:
Your Answer:
Correct Answer: In a negative skew, the mass of distribution is concentrated on the right.
Explanation:Distribution of data is usually unimodal (one peak) but may be bimodal (two peaks) or uniform (no peaks, each value equally likely). The normal distribution is a symmetrical bell-shaped curve. The mean, median, and mode of a normal distribution are equal. In a positive skew, the right tail is longer and the mass of distribution is concentrated on the left; mean > median > mode. In a negative skew, the left tail is longer and the mass of distribution is concentrated on the right; mean < median < mode.
-
This question is part of the following fields:
- Evidence Based Medicine
- Statistics
-
-
Question 38
Incorrect
-
The average BP reading on ambulatory blood pressure monitoring for a 59-year-old Caucasian man is 152/96 mmHg (ABPM).
The first-line drug treatment for this patient would be which of the following? Please only choose ONE answer.Your Answer:
Correct Answer: Amlodipine
Explanation:An ambulatory blood pressure reading of >150/95 is classified as stage 2 hypertension, according to the NICE care pathway for hypertension, and the patient should be treated with an antihypertensive drug.
A calcium-channel blocker, such as amlodipine, would be the most appropriate medication for a 59-year-old Caucasian man.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 39
Incorrect
-
Which of the following is a clinical effect of hyperkalaemia:
Your Answer:
Correct Answer: Muscle weakness
Explanation:Clinical features of hyperkalaemia may include:
paraesthesia, muscle weakness or paralysis, cardiac conduction abnormalities and dysrhythmias.Clinical features of hypokalaemia may include:
muscle weakness, muscle cramps, rhabdomyolysis and myoglobinuria, ascending paralysis resulting in respiratory failure, constipation, gut ileus with distension, anorexia, nausea and vomiting, impaired ADH action with polyuria and polydipsia, ECG changes and cardiac arrhythmias. -
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 40
Incorrect
-
Regarding amoxicillin, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: It is used first line for bacterial tonsillitis.
Explanation:Amoxicillin is a derivative of ampicillin and has a similar antibacterial spectrum. It is better absorbed than ampicillin when given orally, producing higher plasma and tissue concentrations; unlike ampicillin, absorption is not affected by the presence of food in the stomach.
The adverse effects of amoxicillin are mainly gastrointestinal and mild and include nausea, vomiting and diarrhoea. Amoxicillin is used first line for low to moderate severity community acquired pneumonia, exacerbations of chronic bronchitis, for acute otitis media, for acute sinusitis, for oral infections/dental abscess, for Listeria meningitis (in combination with another antibiotic), for infective endocarditis (in combination with another antibiotic) and for H. Pylori eradication (in combination with metronidazole/clarithromycin and a PPI).
Penicillin V is used first line for bacterial tonsillitis; amoxicillin should be avoided in blind treatment of a sore throat as there is a high risk of a rash if glandular fever is present.
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 41
Incorrect
-
A 40-year-old man complains of pain and redness in his lower thigh due to an insect bite. He was diagnosed with cellulitis. Select the first-line antibiotic for cellulitis.
Your Answer:
Correct Answer: Flucloxacillin
Explanation:Cellulitis is most commonly caused by bacteria from the group Aß-hemolytic streptococcus.
Cellulitis can be caused by animal bites. For uncomplicated cellulitis, flucloxacillin is the first-line antibiotic. Because it is beta-lactamase stable, it is efficient against Staphylococcus aureus.
-
This question is part of the following fields:
- Infections
- Microbiology
-
-
Question 42
Incorrect
-
Question 43
Incorrect
-
Most of the lymph from vessels that drain the breast is collected in which of the following lymph nodes?
Your Answer:
Correct Answer: Axillary nodes
Explanation:Lymph is the fluid that flows through the lymphatic system.
Axillary lymph nodes are near the breasts. They are often the first location to which breast cancer spreads if it moves beyond the breast tissue. They receive approximately 75% of lymph drainage from the breast via lymphatic vessels, laterally and superiorly.
The lymph usually first drains to the anterior axillary nodes, and from here, through the central axillary, apical, and supraclavicular nodes in sequence.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 44
Incorrect
-
Which statement about cross-sectional studies is true?
Your Answer:
Correct Answer: They can be used to assess the prevalence of a condition
Explanation:Cross-sectional studies can be used to assess the prevalence of a condition.
Cross-sectional studies CANNOT be used to differentiate between cause and effect or establish the sequence of events.
They can be used to study multiple outcomes but are NOT suitable for studying rare diseases.
-
This question is part of the following fields:
- Evidence Based Medicine
-
-
Question 45
Incorrect
-
A patient presents to your Emergency Department with a laceration on their buttocks requiring closure with sutures.
What stage of wound healing is the first to reach completion?Your Answer:
Correct Answer: Haemostasis
Explanation:The stages of wound healing are: haemostasis, inflammatory, proliferative and remodelling (maturation) phases in that order. The first stage in the healing process of a laceration is haemostasis. Haemostasis is the process of the wound being closed by clotting.
The inflammatory phase occurs just after and up to 48 hours after injury– Blood vessels dilate to allow white blood cells, antibodies, growth factors, enzymes and nutrients to reach the wounded area leading to the characteristic signs of inflammation seen.
Epithelialisation and angiogenesis are not phases of wound healing but occur during the proliferative phase. This ia after haemolysis and inflammation phases have occurred.
The maturation phase is the final phase and occurs when the wound has closed. It involves remodelling of collagen from type III to type I. Apoptosis remove unwanted cells, cellular activity reduces and the number of blood vessels in the wounded area regresses and decreases. This can continues for up to 1 year after injury.
-
This question is part of the following fields:
- General Pathology
- Pathology
-
-
Question 46
Incorrect
-
The most important nerve for plantar flexion of the foot at the ankle joint is:
Your Answer:
Correct Answer: Tibial nerve
Explanation:Muscles of the posterior compartment of the leg, innervated by the tibial nerve, perform plantar flexion of the foot at the ankle joint. The fibularis longus (innervated by the superficial fibular nerve) assists in plantar flexion but is not the most important.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 47
Incorrect
-
All of the following statements are considered true regarding likelihood ratios, except:
Your Answer:
Correct Answer: A likelihood ratio less than 1 indicates that the result is associated with the presence of the disease
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 48
Incorrect
-
A patent has weakness of humeral flexion and extension. A CT scan reveals that he has suffered damage to the nerve that innervates pectoralis major.
Pectoralis major receives its innervation from which of the following nerves? Select ONE answer only.Your Answer:
Correct Answer: Lateral and medial pectoral nerves
Explanation:Pectoralis major is a thick, fan-shaped muscle situated in the chest. It makes up the bulk of the chest musculature in the male and lies underneath the breast in the female. It overlies the thinner pectoralis minor muscle.
Superficial muscles of the chest and arm showing pectoralis major (from Gray’s Anatomy)
Pectoralis major has two heads; the clavicular head and the sternocostal head. The clavicular head originates from the anterior border and medial half of the clavicle. The sternocostal head originates from the anterior surface of the sternum, the superior six costal cartilages and the aponeurosis of the external oblique muscle. It inserts into the lateral lip of the bicipital groove of the humerus.
Pectoralis major receives dual innervation from the medial pectoral nerve and the lateral pectoral nerve.
Its main actions are as follows:
Flexes humerus (clavicular head)
Extends humerus (sternocostal head)
Adducts and medially rotates the humerus
Draws scapula anteriorly and inferiorly -
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 49
Incorrect
-
A novel anti-tuberculosis medicine was compared to standard treatment and shown to cut the risk of death from 30 to 10 per 1000 people. How many patients would need to be treated (number need to treat (NNT)) in order to prevent 10 additional tuberculosis deaths:
Your Answer:
Correct Answer: 500
Explanation:The risk of mortality in the control group (usual therapy) minus the risk of death in the treatment group equals the absolute risk reduction (ARR) of treatment.
30/1000 minus 10/1000 = 20/1000 = 0.02NNT = 1/ARR = 1/0.02 = 50
As a result, 50 people would need to be treated in order to prevent one additional fatality, and 500 people would need to be treated in order to avoid 10 additional deaths. -
This question is part of the following fields:
- Evidence Based Medicine
- Statistics
-
-
Question 50
Incorrect
-
A somatostatinoma is diagnosed in a 74-year-old patient who has recently developed diabetes mellitus, recurrent episodes of gallstones, and Steatorrhoea. She also has a tumour in the head of her pancreas.
Which of the following is the most likely effect of this tumour?Your Answer:
Correct Answer: Inhibit gastric acid secretion
Explanation:Somatostatin-producing cells present in the pyloric antrum, duodenum, and pancreatic islets are known as D-cells or delta-cells. Somatostatin inhibits gastric acid secretion by acting directly on acid-producing parietal cells in the stomach via a G-protein coupled receptor.
Somatostatin affects hormones in the following ways:
Inhibits the anterior pituitary’s secretion of growth hormone.
Inhibits the anterior pituitary’s secretion of thyroid-stimulating hormone.The secretion of various gastrointestinal hormones is inhibited (including gastrin, CCK, secretin, motilin, VIP and GIP)
Reduces the rate at which the stomach empties.
Inhibits the release of insulin and glucagon from the pancreas.The pancreas’ exocrine secretory activity is inhibited.
Somatostatin can also slow the digestive process by suppressing the production of hormones such gastrin, secretin, and histamine, which reduces gastric acid secretion.A somatostatinoma is a cancerous tumour of the endocrine pancreas’ D-cells, which make somatostatin. Somatostatin inhibits pancreatic and gastrointestinal hormones when levels are high. The following clinical characteristics are related with somatostatinomas:
Insulin secretion blockage causes diabetes mellitus.
Gallstones by inhibition of CCK and secretin Steatorrhoea via inhibition of CCK and secretinHypochlorhydria is caused by the suppression of gastrin, a hormone that increases gastric acid output regularly.
-
This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
-
-
Question 51
Incorrect
-
Which of the following is an action of glucagon:
Your Answer:
Correct Answer: Stimulates glycogenolysis
Explanation:Glucagon is a peptide hormone that is produced and secreted by alpha cells of the islets of Langerhans, which are located in the endocrine portion of the pancreas. The main physiological role of glucagon is to stimulate hepatic glucose output, thereby leading to increases in glycaemia. It provides the major counter-regulatory mechanism to insulin in maintaining glucose homeostasis.
Hypoglycaemia is the principal stimulus for the secretion of glucagon but may also be used as an antidote in beta-blocker overdose and in anaphylaxis in patients on beta-blockers that fail to respond to adrenaline.
Glucagon then causes:
Glycogenolysis
Gluconeogenesis
Lipolysis in adipose tissue
The secretion of glucagon is also stimulated by:
Adrenaline
Cholecystokinin
Arginine
Alanine
Acetylcholine
The secretion of glucagon is inhibited by:
Insulin
Somatostatin
Increased free fatty acids
Increased urea productionGlycolysis is the metabolic pathway that converts glucose into pyruvate. The free energy released by this process is used to form ATP and NADH. Glycolysis is inhibited by glucagon, and glycolysis and gluconeogenesis are reciprocally regulated so that when one cell pathway is activated, the other is inactive and vice versa.
Glucagon has a minor effect of enhancing lipolysis in adipose tissue. Lipolysis is the breakdown of lipids and involves the hydrolysis of triglycerides into glycerol and free fatty acids. It makes fatty acids available for oxidation.
-
This question is part of the following fields:
- Endocrine
- Pharmacology
-
-
Question 52
Incorrect
-
Aldin is a 24-year-old male patient who arrives at the emergency department diagnosed with psittacosis based on his symptoms and history of being a pigeon enthusiast. Which of the following is the causative bacteria of psittacosis?
Your Answer:
Correct Answer: Chlamydia psittaci
Explanation:Chlamydia psittaci is a microorganism that is commonly found in birds.
These bacteria can infect people and cause psittacosis. Psittacosis is an infectious disease that may cause high fever and pneumonia associated with headaches, altered mental state, and hepatosplenomegaly.
-
This question is part of the following fields:
- Infections
- Microbiology
-
-
Question 53
Incorrect
-
How does dipyridamole mediate its antiplatelet effect:
Your Answer:
Correct Answer: It is a phosphodiesterase inhibitor.
Explanation:Dipyridamole inhibits both the reuptake of adenosine and phosphodiesterase, preventing the degradation of cAMP and thus blocking the platelet aggregation response to ADP.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 54
Incorrect
-
Regarding saliva, which of the following statements is CORRECT:
Your Answer:
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
-
-
Question 55
Incorrect
-
Myocardial contractility is best correlated with the intracellular concentration of:
Your Answer:
Correct Answer: Ca2+
Explanation:Contractility of myocardial cells depends on the intracellular [Ca2+], which is regulated by Ca2+entry across the cell membrane during the plateau of the action potential and by Ca2+uptake into and release from the sarcoplasmic reticulum (SR).
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 56
Incorrect
-
Injury to which nerve can lead to weakness or paralysis of the brachialis muscle?
Your Answer:
Correct Answer: The musculocutaneous nerve
Explanation:The brachialis muscle is a prime flexor of the forearm at the elbow joint. It is fusiform in shape and located in the anterior (flexor) compartment of the arm, deep to the biceps brachii. The brachialis is a broad muscle, with its broadest part located in the middle rather than at either of its extremities. It is sometimes divided into two parts, and may fuse with the fibres of the biceps brachii, coracobrachialis, or pronator teres muscles. It also functions to form part of the floor of the cubital fossa.
The brachialis is primarily supplied by the musculocutaneous nerve (C5, C6). In addition, a small lateral portion of the muscle is innervated by the radial nerve (C7).
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 57
Incorrect
-
You assess a patient that has suffered a nerve injury that has paralysed her left latissimus dorsi muscle.
Latissimus dorsi receives its innervation from which of the following nerves? Select ONE answer only.Your Answer:
Correct Answer: Thoracodorsal nerve
Explanation:Latissimus dorsi originates from the lower part of the back, where it covers a wide area. It lies underneath the inferior fibres of trapezius superiorly, and trapezius is the most superficial back muscle.
Superficial muscles of the back showing latissimus dorsi (from Gray’s Anatomy)
Latissimus dorsi has a broad origin, arising from the spinous processes of T6-T12, the thoracolumbar fascia, the iliac crest and the inferior 3 or 4 ribs. The fibres converge into a tendon that inserts into the intertubercular groove of the humerus.
Latissimus dorsi is innervated by the thoracodorsal nerve.
Latissimus dorsi acts to extend, adduct and medially rotate the humerus. It, therefore, raises the body towards the arm during climbing. -
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 58
Incorrect
-
The sensation produced by touching the arm with a vibrating tuning fork during a neurological examination is mediated by which of the following spinal tracts:
Your Answer:
Correct Answer: Posterior column
Explanation:Fine-touch, proprioception and vibration sensation are mediated by the posterior column-medial lemniscus pathway.
-
This question is part of the following fields:
- Anatomy
- Central Nervous System
-
-
Question 59
Incorrect
-
In the emergency room, a 28-year-old woman complains of wobbly and slurred speech, is unable to do the heel-shin test, and has nystagmus. The following signs are most likely related to damage to which of the following areas:
Your Answer:
Correct Answer: Cerebellum
Explanation:Cerebellar injury causes delayed and disorganized motions. When walking, people with cerebellar abnormalities sway and stagger.
Damage to the cerebellum can cause asynergia, the inability to judge distance and when to stop, dysmetria, the inability to perform rapid alternating movements or adiadochokinesia, movement tremors, staggering, wide-based walking or ataxic gait, a proclivity to fall, weak muscles or hypotonia, slurred speech or ataxic dysarthria, and abnormal eye movements or nystagmus.
-
This question is part of the following fields:
- Anatomy
- Central Nervous System
-
-
Question 60
Incorrect
-
A 59-year-old man presents to the emergency room with chest pain. The cardiology team recently discharged him. He underwent a procedure and was given several medications, including abciximab, during his stay. Which of the following statements about abciximab is correct?
Your Answer:
Correct Answer: It is a glycoprotein IIa/IIIb receptor antagonist
Explanation:Abciximab (ReoPro) is a glycoprotein IIb/IIIa receptor antagonist that is a chimeric monoclonal antibody. It is primarily used during and after coronary artery procedures such as angioplasty to inhibit platelet aggregation.
It’s approved for use as a supplement to heparin and aspirin in high-risk patients undergoing percutaneous transluminal coronary intervention to prevent ischaemic complications. Only one dose of abciximab should be given (to avoid additional risk of thrombocytopenia).
Before using, it is recommended that baseline prothrombin time, activated clotting time, activated partial thromboplastin time, platelet count, haemoglobin, and haematocrit be measured. 12 and 24 hours after starting treatment, haemoglobin and haematocrit should be measured again, as should platelet count 2-4 hours and 24 hours after starting treatment.
When used for high-risk patients undergoing angioplasty, the EPIC trial(link is external)found that abciximab reduced the risk of death, myocardial infarction, repeat angioplasty, bypass surgery, and balloon pump insertion.The use of abciximab is contraindicated in the following situations:
Internal bleeding is present.
Within the last two months, you’ve had major surgery, intracranial surgery, or trauma.
Stroke in the previous two years
Intracranial tumour
Aneurysm or arteriovenous malformation
Haemorrhagic diathesis is a type of haemorrhagic diathesis.
Vasculitis
Retinopathy caused by hypertensionThe following are some of the most common abciximab side effects:
Manifestations of bleeding
Bradycardia
Back ache
Pain in the chest
Vomiting and nausea
Pain at the puncture site
Thrombocytopenia -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 61
Incorrect
-
In a VF arrest, a 6-year-old child is brought to your Emergency Department resuscitation area. He weighs 16 kilogrammes. He's had three DC shocks, but he's still in VF and doesn't have an output.
What amiodarone dose should he get now, according to the most recent APLS guidelines?Your Answer:
Correct Answer: 80 mg
Explanation:In a shockable (Vf/pVT) paediatric cardiac arrest, amiodarone should be administered after the third and fifth shocks. The dose is 5 mg/kg (maximum 300 mg) and should be administered over a three-minute period. If at all possible, administration via a central line is recommended.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 62
Incorrect
-
A 62 year old man has sustained a penetrating injury to the submandibular triangle. On examination, his tongue is weak and when protruded deviates to the left. Which of the following nerves has most likely been injured:
Your Answer:
Correct Answer: Left hypoglossal nerve
Explanation:Damage to the hypoglossal nerve results in weakness of the tongue, with deviation of the tongue towards the weak side on protrusion.
-
This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
-
-
Question 63
Incorrect
-
Nitrous oxide is associated with which of the following adverse effects:
Your Answer:
Correct Answer: Megaloblastic anaemia
Explanation:Exposure to nitrous oxide for prolonged periods, either by continuous or by intermittent administration, may result in megaloblastic anaemia as a result of interference with the action of vitamin B12; neurological toxic effects can occur without preceding overt haematological changes. Depression of white cell formation may also occur.
-
This question is part of the following fields:
- Anaesthesia
- Pharmacology
-
-
Question 64
Incorrect
-
The pelvic bone is formed by which of the following:
Your Answer:
Correct Answer: Ilium, ischium and pubis
Explanation:Each pelvic bone is formed by three elements: the ilium (superiorly), the pubis (anteroinferiorly) and the ischium (posteroinferiorly).
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 65
Incorrect
-
Which of the following statement is correct with regards to the female urethra?
Your Answer:
Correct Answer: The urethra opens in the vestibule that lies between the labia minora.
Explanation:The urethra in women is short (about 4 cm long), and begins at the base of the bladder. Its course runs inferiorly through the urogenital diaphragm, then into the perineum. It then opens in the vestibule which lies between the labia minora. The inferior aspect of the urethra is bound to the anterior surface of the vagina. The urethral opening is anterior to the vaginal opening in the vestibule. As the urethra passes through the pelvic floor, it is surrounded by the external urethral sphincter.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 66
Incorrect
-
A 28-year-old asthmatic patient is seen in the Emergency Department following an acute exacerbation. His symptoms start to improve when your consultant gives him a high dose of IV aminophylline.
Which of the following is correct mechanism of action of aminophylline ?Your Answer:
Correct Answer: Inhibition of phosphodiesterase
Explanation:Aminophylline has the following properties:
Phosphodiesterase inhibitor that increases intracellular cAMP and relaxes smooth muscle in the bronchial airways and pulmonary blood vessels.
Mast cell stabilization is achieved by using a non-selective adenosine receptor antagonist. -
This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
-
-
Question 67
Incorrect
-
Regarding hypernatraemia, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: In acute severe hypernatraemia, seizures and intracranial vascular haemorrhage can occur as a result of brain cell lysis.
Explanation:Acute severe hypernatraemia is a medical emergency and requires inpatient management in a high dependency setting. Seizures and intracranial vascular haemorrhage as a result of brain cell crenation can occur. The cause is most commonly excessive water loss and the key aspect of treatment is aggressive fluid replacement (typically with normal saline as this is relatively hypotonic). If urine osmolality is low, diabetes insipidus (DI )should be considered and a trial of synthetic ADH given. In patients with known DI, it is essential to ensure synthetic ADH is given parenterally and that close fluid balance is observed.
-
This question is part of the following fields:
- Endocrine
- Physiology
-
-
Question 68
Incorrect
-
Regarding the extensor carpi ulnaris muscle, which of the following statements is true?
Your Answer:
Correct Answer: It receives its blood supply from the ulnar artery
Explanation:Extensor carpi ulnaris is a fusiform muscle in the posterior forearm. It spans between the elbow and base of the little finger. This muscle belongs to the superficial forearm extensor group, along with anconaeus, brachioradialis, extensor carpi radialis longus, extensor carpi radialis brevis, extensor digitorum and extensor digiti minimi muscles.
Like all the muscles of this compartment, extensor carpi ulnaris works as an extensor of the wrist. Moreover, due to its specific course, this muscle also acts to adduct the hand.
Extensor carpi ulnaris is innervated by the posterior interosseous nerve (C7, C8), a branch of the deep division of the radial nerve. The radial nerve stems from the posterior cord of the brachial plexus.
Blood supply to the extensor carpi ulnaris muscle is provided by branches of the radial recurrent and posterior interosseous arteries, which stem from the radial and ulnar arteries, respectively.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 69
Incorrect
-
The following are all important buffers of H+EXCEPT for:
Your Answer:
Correct Answer: Calcium
Explanation:Buffers are weak acids or bases that can donate or accept H+ions respectively and therefore resist changes in pH. Buffering does not alter the body’s overall H+load, ultimately the body must get rid of H+by renal excretion if the buffering capacity of the body is not to be exceeded and a dangerous pH reached. Bicarbonate and carbonic acid (formed by the combination of CO2 with water, potentiated by carbonic anhydrase) are the most important buffer pair in the body, although haemoglobin provides about 20% of buffering in the blood, and phosphate and proteins provide intracellular buffering. Buffers in urine, largely phosphate, allow the excretion of large quantities of H+.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 70
Incorrect
-
A possible diagnosis of Cushing's illness is being investigated in an overweight patient with resistant hypertension. A CRH (corticotropin-releasing hormone) test is scheduled.
Which of the following statements about corticotropin-releasing hormone is correct?Your Answer:
Correct Answer: It is produced by cells within the paraventricular nucleus of the hypothalamus
Explanation:Corticotropin-releasing hormone (CRH) is a neurotransmitter and peptide hormone. It is generated by cells in the hypothalamic paraventricular nucleus (PVN) and released into the hypothalamo-hypophyseal portal system at the median eminence through neurosecretory terminals of these neurons. Stress causes the release of CRH.
The CRH is carried to the anterior pituitary through the hypothalamo-hypophyseal portal system, where it activates corticotrophs to release adrenocorticotropic hormone (ACTH). Cortisol, glucocorticoids, mineralocorticoids, and DHEA are all produced in response to ACTH.
Excessive CRH production causes the size and quantity of corticotrophs in the anterior pituitary to expand, which can lead to the creation of a corticotrope tumour that generates too much ACTH.
-
This question is part of the following fields:
- Endocrine Physiology
- Physiology
-
-
Question 71
Incorrect
-
Typically, granulomatous inflammation is associated with one of the following infections:
Your Answer:
Correct Answer: Tuberculosis
Explanation:Granulomatous inflammation is typically seen when an infective agent with a digestion-resistance capsule (e.g. Mycobacterium tuberculosis) or a piece of inert foreign material (such as suture or glass) is introduced into the tissue. A transient acute inflammatory response occurs and when this is ineffective in eradicating the stimulus, chronic inflammation occurs.
Tuberculosis is the prototype of the granulomatous diseases, but sarcoidosis, cat-scratch disease, lymphogranuloma inguinale, leprosy, brucellosis, syphilis, some mycotic infections, berylliosis, reactions of irritant lipids, and some autoimmune diseases are also included
-
This question is part of the following fields:
- Inflammatory Responses
- Pathology
-
-
Question 72
Incorrect
-
A 29-year-old man presents with painful red eye with copious discharge and you make a diagnosis of infective conjunctivitis following a history and an examination,.
One of these is NOT an indication for an urgent ophthalmology referral in this patient.
Your Answer:
Correct Answer: Bilateral conjunctivitis
Explanation:Urgent referral to ophthalmology is indicated if the patient with conjunctivitis has any of the following:
Suspected gonococcal or chlamydial conjunctivitis
Corneal involvement associated with soft contact lens use
Severe disease indicated by presence of a pseudomembrane
Conjunctivitis associated with rheumatoid arthritis or in immunocompromised patient. Ophthalmia neonatorum.
Possible herpes infection.
Had recent intraocular surgery. A red flag indicating a serious cause of red eye.
Suspected periorbital or orbital cellulitis.Bilateral conjunctivitis is not an indication for urgent referral to ophthalmology.
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 73
Incorrect
-
A patient is diagnosed as having a glucagonoma. Her blood serum glucagon concentration is 1246 pg/mL.
Glucagon is produced in which of the following cells? Select ONE answer only.Your Answer:
Correct Answer: Alpha-cells in the pancreas
Explanation:Glucagon is a peptide hormone that is produced and secreted by alpha cells of the islets of Langerhans, which are located in the endocrine portion of the pancreas. The main physiological role of glucagon is to stimulate hepatic glucose output, thereby leading to increases in glycaemia. It provides the major counter-regulatory mechanism to insulin in maintaining glucose homeostasis.
Hypoglycaemia is the principal stimulus for the secretion of glucagon but may also be used as an antidote in beta-blocker overdose and in anaphylaxis in patients on beta-blockers that fail to respond to adrenaline.
Glucagon then causes:
Glycogenolysis
Gluconeogenesis
Lipolysis in adipose tissue
The secretion of glucagon is also stimulated by:
Adrenaline
Cholecystokinin
Arginine
Alanine
Acetylcholine
The secretion of glucagon is inhibited by:
Insulin
Somatostatin
Increased free fatty acids
Increased urea productionGlycolysis is the metabolic pathway that converts glucose into pyruvate. The free energy released by this process is used to form ATP and NADH. Glycolysis is inhibited by glucagon, and glycolysis and gluconeogenesis are reciprocally regulated so that when one cell pathway is activated, the other is inactive and vice versa.
Glucagon has a minor effect of enhancing lipolysis in adipose tissue. Lipolysis is the breakdown of lipids and involves the hydrolysis of triglycerides into glycerol and free fatty acids. It makes fatty acids available for oxidation.
-
This question is part of the following fields:
- Endocrine Physiology
- Physiology
-
-
Question 74
Incorrect
-
Which of the following causes the first heart sound?
Your Answer:
Correct Answer: Closing of the atrioventricular valves
Explanation:The heart sounds are as a result of the various parts of the cardiac cycle.
Heart Sound – Phase of Cardiac Cycle – Mechanical Event:
1st heart sound – Systole starts – there is closure of the atrioventricular (mitral & tricuspid) valves
2nd heart sound – Systole ends – there is closure of the semilunar (aortic and pulmonary) valves
3rd heart sound – Early diastole – this is caused by rapid flow of blood from the atria into the ventricles during the ventricular filling phase
4th heart sound – Late diastole – this is caused by filling of an abnormally stiff ventricle in atrial systole -
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 75
Incorrect
-
Which of the following is NOT a typical side effect of digoxin:
Your Answer:
Correct Answer: Hypokalaemia
Explanation:Digoxin does not cause hypokalaemia, but hypokalaemia does potentiate digoxin toxicity. The adverse effects of digoxin are frequently due to its narrow therapeutic window and include:
Cardiac adverse effects – Sinoatrial and atrioventricular block, Premature ventricular contractions, PR prolongation and ST-segment depression
Nausea, vomiting and diarrhoea
Blurred or yellow vision
CNS effects – weakness, dizziness, confusion, apathy, malaise, headache, depression, psychosis
Thrombocytopenia and agranulocytosis (rare)
Gynaecomastia in men in prolonged administration -
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 76
Incorrect
-
Which of the following nerves supply the superficial head of the flexor pollicis brevis muscle?
Your Answer:
Correct Answer: The recurrent branch of the median nerve
Explanation:The two heads of the flexor pollicis brevis usually differ in their innervation. The superficial head of flexor pollicis muscle receives nervous supply from the recurrent branch of the median nerve, whereas the deep head receives innervation from the deep branch of the ulnar nerve, derived from spinal roots C8 and T1.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 77
Incorrect
-
One of your patients has been infected by an obligate pathogen and presents with features of this condition.
Which of these is an example of an obligate pathogen?
Your Answer:
Correct Answer: Trepenoma pallidum
Explanation:Treponema pallidum is an obligate pathogen. Obligate pathogens are almost always associated with disease and usually cannot survive outside of the body for long periods of time. Examples include and HIV.
Staphylococcus aureus and Bacteroides fragilis are conditional pathogens. These are pathogens that usually cause disease only if certain conditions are met.
Pneumocystis jiroveci and Pseudomonas aeruginosa, are opportunistic pathogens. These are pathogens that can only cause disease in an immunocompromised host or under unusual circumstances.
-
This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
-
-
Question 78
Incorrect
-
A patient has a cardiac output of 4.8 L/min and a heart rate of 80 bpm, therefore their stroke volume is:
Your Answer:
Correct Answer: 60 mL
Explanation:Cardiac output (CO) = Stroke volume (SV) x Heart rate (HR).
Therefore SV = CO/HR
= 4.8/80
= 0.06 L = 60 mL. -
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 79
Incorrect
-
Which of the following nerves is responsible for the symptoms of a patient with history of recurrent herpes simplex outbreaks on his face and presents with ophthalmic herpes zoster and a painful vesicle on the tip of his nose?
Your Answer:
Correct Answer: Nasociliary nerve
Explanation:Hutchinson sign relates to involvement of the tip of the nose from facial herpes zoster. It implies involvement of the external nasal branch of the nasociliary nerve which is a branch of the ophthalmic division of the trigeminal nerve.
The nasociliary branch of the trigeminal nerve innervates the apex and lateral aspect of the nose, as well as the cornea. Therefore, lesions on the side or tip of the nose should raise suspicion of ocular involvement.
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 80
Incorrect
-
A 50-year-old man from Russia presents with a history of cough with blood-stained sputum, fever, night sweats, and weight loss. Suspecting tuberculosis, you begin investigations.
All the following statements regarding tuberculosis (TB) are true EXCEPT?Your Answer:
Correct Answer: Corticosteroid use is not a risk factor for developing TB
Explanation:Immunosuppressants like corticosteroids may be an important risk factor for developing tuberculosis.
All of the other statements are true.
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 81
Incorrect
-
The causative organism for an infection in a patient you are reviewing is a facultative anaerobe.
Which of these is a facultative anaerobic organism?Your Answer:
Correct Answer: Staphylococcus aureus
Explanation:Facultative anaerobic bacteria make energy in the form of ATP by aerobic respiration in an oxygen rich environment and can switch to fermentation in an oxygen poor environment.
Examples of facultative anaerobes are:
Staphylococcus spp.
Listeria spp.
Streptococcus spp.
Escherichia coliMycobacterium tuberculosis, and Pseudomonas aeruginosa are obligate aerobe. They require oxygen to grow
Campylobacter jejuni and Clostridium spp are obligate anaerobes.
They live and grow in the absence of oxygen. -
This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
-
-
Question 82
Incorrect
-
Which of the following does NOT affect the rate of flow of a liquid through a tube:
Your Answer:
Correct Answer: Surface tension
Explanation:Flow through a tube is dependent upon:
The pressure difference across the ends of the tube (P1– P2)
The resistance to flow provided by the tube (R)
This is Darcy’s law, which is analogous to Ohm’s law in electronics:
Flow = (P1– P2) / R
Resistance in the tube is defined by Poiseuille’s law, which is determined by the diameter of the tube and the viscosity of the fluid. Poiseuille’s law is as follows:
Resistance = (8VL) / (Ï€R4)
Where:
V = The viscosity of the fluid
L = The length of the tube
R = The radius of the tube
Therefore, in simple terms, resistance is directly proportional to the viscosity of the fluid and the length of the tube and inversely proportional to the radius of the tube. Of these three factors, the most important quantitatively and physiologically is vessel radius.
It can be seen that small changes in the radius can have a dramatic effect on the flow of the fluid. For example, the constriction of an artery by 20% will decrease the flow by approximately 60%.
Another important and frequently quoted example of this inverse relationship is that of the radius of an intravenous cannula. Doubling the diameter of a cannula increases the flow rate by 16-fold (r4). This is the reason the diameter of an intravenous cannula in resuscitation scenarios is so important.
*Please note that knowledge of the detail of Poiseuille’s law is not a requirement of the RCEM Basic Sciences Curriculum. -
This question is part of the following fields:
- Basic Cellular
- Physiology
-
-
Question 83
Incorrect
-
After returning from Thailand two days ago, a 61-year-old man presents to the department with severe diarrhoea and vomiting. He has a history of hypertension and takes an ACE inhibitor to treat it.
Which of the following statements about angiotensin-converting enzyme inhibitors is correct?Your Answer:
Correct Answer: They have been shown to reduce mortality in heart failure
Explanation:Angiotensin-converting enzyme (ACE) inhibitors prevent angiotensin I from being converted to angiotensin II. Angiotensin II has a variety of effects:
Sympathetic activity has increased.
Vasoconstriction in the arteries
Secretion of Vasopressin
Secretion of aldosteroneThe increase in systemic blood pressure is caused by arteriolar vasoconstriction. Vasopressin stimulates water reabsorption in the kidneys as well as the thirst sensation. In the distal convoluted tubules and collecting ducts, aldosterone causes the reabsorption of sodium and water from the urine in exchange for potassium secretion. As a result, ACE inhibitors lower systemic blood pressure while also causing hyperkalaemia.
Angiotensin-converting enzyme inhibitors (ACE inhibitors) are used in a variety of clinical settings, including heart failure. According to a meta-analysis, ACE inhibitors reduce death, MI, and overall admission in patients with heart failure by 28%.
ACE inhibitors are also used in the following clinical settings:
Hypertension
Chronic kidney disease
Diabetic nephropathyÂ
Following a myocardial infarctionIn the presence of renal artery stenosis, ACE inhibitors are contraindicated because they can cause or exacerbate renal failure.
The most common side effect of ACE inhibitors is a dry cough caused by increased bradykinin production. There is, however, no known link to fibrosis of the lungs. -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 84
Incorrect
-
A 25 year old man presents to the emergency room with abdominal pain, vomiting and constipation. A CT scan is done which is suggestive of Meckel's diverticulum. Where does the blood supply of the Meckel's diverticulum originate?
Your Answer:
Correct Answer: Superior mesenteric artery
Explanation:Meckel’s diverticulum has certain classic characteristics.
1. It lies on the antimesenteric border of the middle-to-distal ileum
2. It is approximately 2 feet proximal to the ileocaecal junction
3. It appears as a blind-ended tubular outpouching of bowel
4. It is about 2 inches long,
5. It occurs in about 2% of the population,
6. It may contain two types of ectopic tissue (gastric and pancreatic).
7. The diverticulum is supplied by the superior mesenteric artery.
8. Proximal to the major duodenal papilla the duodenum is supplied by the gastroduodenal artery (branch of the coeliac trunk)
9. Distal to the major duodenal papilla it is supplied by the inferior pancreaticoduodenal artery (branch of superior mesenteric artery).
10. The arterial supply to the jejunoileum is from the superior mesenteric artery. -
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 85
Incorrect
-
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:
Correct 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
-
-
Question 86
Incorrect
-
The ECG of a patient presenting with a history of intermittent palpitations has a prolonged QT interval.
Which of these can cause prolongation of the QT interval on the ECG?Your Answer:
Correct Answer: Hypomagnesaemia
Explanation:The causes of a prolonged QT interval include:
Hypomagnesaemia
Hypothermia
Hypokalaemia
Hypocalcaemia
Hypothyroidism
Jervell-Lange-Nielsen syndrome (autosomal dominant)
Romano Ward syndrome (autosomal recessive)
Ischaemic heart disease
Mitral valve prolapse
Rheumatic carditis
Erythromycin
Amiodarone
Quinidine
Tricyclic antidepressants
Terfenadine
Methadone
Procainamide
Sotalol -
This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
-
-
Question 87
Incorrect
-
As part of his angina treatment, a 68-year-old man is prescribed a beta blocker. He starts having nightmares and has trouble sleeping soon after starting the beta-blocker.
Which of the beta blockers listed below is the most likely to be in his system?Your Answer:
Correct Answer: Propranolol
Explanation:The beta-adrenoceptors in the heart, peripheral vasculature, bronchi, pancreas, and liver are blocked by beta-adrenoceptor blocking drugs (beta blockers).
Beta blockers come in a wide range of strengths, with the choice largely determined by the disease being treated and the patient’s unique circumstances. The intrinsic sympathomimetic activity, lipid solubility, duration of action, and cardioselectivity of beta blockers all differ.
Some beta blockers are lipid (lipophilic) soluble, while others are water soluble (hydrophilic). Drugs that are more lipid-soluble are absorbed faster from the gut, undergo more first-pass metabolism, and are eliminated faster. They’re also more likely to get into the brain and cause central effects like insomnia and nightmares. Propranolol, pindolol, labetalol, and metoprolol are examples of lipid-soluble beta blockers. Beta blockers that are water-soluble are less likely to enter the brain and are more resistant to first-pass metabolism. They are excreted by the kidneys, and in renal impairment, dosage reduction is frequently required. Atenolol, nadolol, celiprolol, and sotalol are examples of water-soluble beta blockers.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 88
Incorrect
-
C5 - C9 deficiency increases susceptibility to infection with which of the following:
Your Answer:
Correct Answer: Neisseria spp.
Explanation:If the complement sequence is completed, an active phospholipase (the membrane attack complex, MAC) is produced, which punches holes in the cell membrane and causes cell lysis. Because the MAC appears to be the sole means to destroy the Neisseria family of bacteria, C5 – C9 deficiency increases susceptibility to Neisseria infections.
-
This question is part of the following fields:
- Immune Responses
- Pathology
-
-
Question 89
Incorrect
-
The most common type of adult leukaemia is chronic lymphocytic leukaemia (CLL). It develops as a result of lymphocyte clonal proliferation. Which of the following statements about CLL is CORRECT?
Your Answer:
Correct Answer: It is most commonly discovered as an incidental finding
Explanation:CLL (chronic lymphocytic leukaemia) is the most common type of chronic lymphoid leukaemia, with a peak incidence between the ages of 60 and 80. It is the most common type of leukaemia in Europe and the United States, but it is less common elsewhere.
The CLL tumour cell is a mature B-cell with low immunoglobulin surface expression (IgM or IgD). The average age at diagnosis is 72 years, with only 15% of cases occurring before the age of 50.
The male-to-female ratio is about 2:1. Over 80% of cases are identified by the results of a routine blood test, which is usually performed for another reason.
Lymphocytic anaemia, thrombocytopenia, and normochromic normocytic anaemia are common laboratory findings. Aspiration of bone marrow reveals up to 95% lymphocytic replacement of normal marrow elements.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 90
Incorrect
-
A 23-year-old student presents with a fever and sore throat. Upon physical examination, it was observed that he had bilaterally enlarged tonsils that are covered in large amounts of exudate. A diagnosis of tonsillitis was made.
The lymph from the tonsils will drain to which of the following nodes?Your Answer:
Correct Answer: Deep cervical lymph nodes
Explanation:The tonsils are collections of lymphatic tissue located within the pharynx. They collectively form a ringed arrangement, known as Waldeyer’s ring: pharyngeal tonsil, 2 tubal tonsils, 2 palatine tonsils, and the lingual tonsil.
Lymphatic fluid from the lingual tonsil drains into the jugulodigastric and deep cervical lymph nodes.
Lymphatic fluid from the pharyngeal tonsil drains into the retropharyngeal nodes (which empty into the deep cervical chain), and directly into deep cervical nodes within the parapharyngeal space.
The retropharyngeal and the deep cervical lymph nodes drain the tubal tonsils.
The palatine tonsils drain to the jugulodigastric node, a node of the deep cervical lymph nodes, located inferior to the angle of the mandible.
-
This question is part of the following fields:
- Anatomy
- Head And Neck
-
-
Question 91
Incorrect
-
You have been asked to give a tutorial on common upper limb neurology to a group of medical students. You use the example of a man falling from a balcony onto spiked fencing, sustaining a puncture wound to the axilla. This results in an injury to the musculocutaneous nerve. Which of the following clinical features would you LEAST expect to see in this patient:
Your Answer:
Correct Answer: Weakness of forearm pronation
Explanation:Flexion of the arm and flexion and supination of the forearm are weakened but not lost entirely due to the actions of the pectoralis major and deltoid, the brachioradialis and the supinator muscles respectively. There is loss of sensation over the lateral aspect of the forearm. Forearm pronation would not be affected as this is primarily produced by the pronator quadratus and pronator teres muscles, innervated by the median nerve.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 92
Incorrect
-
Which of the following ions normally has the highest concentration in intracellular fluid:
Your Answer:
Correct Answer: K +
Explanation:Potassium (K+) is the principal intracellular ion; approximately 4 mmol/L is extracellular (3%) and 140 mmol/L intracellular (97%).
-
This question is part of the following fields:
- Basic Cellular
- Physiology
-
-
Question 93
Incorrect
-
Which of the following increases the tendency for oedema to occur?
Your Answer:
Correct Answer: Increased venous pressure
Explanation:When more fluid is filtered out of the capillaries than can be returned to the circulation by the lymphatics, oedema occurs. Changes that increase capillary hydrostatic pressure or decrease plasma oncotic pressure will increase filtration.
Arteriolar constriction reduces hydrostatic capillary pressure and transiently increase absorption of fluid.
Dehydration increases plasma protein concentration and therefore increases plasma oncotic pressure and absorption. Capillary hydrostatic pressure and filtration are increased when there is increased venous pressure. -
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 94
Incorrect
-
On which of the following types of receptors does loperamide act?
Your Answer:
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
-
-
Question 95
Incorrect
-
Lidocaine's mechanism of action as a local aesthetic is as follows:
Your Answer:
Correct Answer: Blocks influx of Na+ through voltage-gated Na+ channels
Explanation:Local anaesthetics prevent generation/conduction of nerve impulses by reducing sodium permeability and increasing action potential threshold; inhibits depolarization, which results in blockade of conduction
-
This question is part of the following fields:
- Anaesthesia
- Pharmacology
-
-
Question 96
Incorrect
-
A patient complains of stomach ache. You see a midline scar in the epigastric area when you examine the abdomen. Upon further interrogation, the patient reveals that she had a subtotal gastrectomy for recurring stomach ulcers several years ago. The stomach mucosa secretes a variety of vital compounds, and her ability to secrete some of these molecules has been harmed as a result of his surgery.
The stomach G-cells are responsible for which of the following?Your Answer:
Correct Answer: Secretion of gastrin
Explanation:G-cells are a type of cell found in the stomach’s pyloric antrum, duodenum, and pancreas. The secretion of the peptide hormone gastrin is their major function.
The table below summarizes the many cell types found in the stomach, as well as the substances secreted by each cell type and the function of the secretion:
Cell type/ Substance secreted/ Function of secretion
Parietal cells/ Hydrochloric acid/ Kills microbes and activates pepsinogen
Parietal cells/ Intrinsic factor/Binds to vitamin B12 and facilitates its absorption
Chief cells/ Pepsinogen/ Protein digestion
Chief cells/ Gastric lipase/ Fat digestion
G-cells/ Gastrin/ Stimulates gastric acid secretion
Enterochromaffin-like cells (ECL cells) /Histamine/ Stimulates gastric acid secretion
Mucous-neck cells/ Mucous and bicarbonate/ Protects stomach epithelium from acid
D-cells/ Somatostatin/ Inhibits gastric acid secretion -
This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
-
-
Question 97
Incorrect
-
A 1-year-old male is brought to the paediatrician by his mother due to swelling of the right knee after a minor fall. On examination, the right knee is swollen, fluctuant and tender. Ultrasound-guided aspiration reveals a massive hemarthrosis. Family history shows that his older brother also has a bleeding disorder.
Which one of the following conditions does the patient most likely have?Your Answer:
Correct Answer: Haemophilia A
Explanation:A diagnosis of Haemophilia is supported in this patient by the family history and the presence of hemarthrosis-both characteristics of Haemophilia. Haemophilia A is caused by Factor VIII deficiency, leading to impaired coagulation. This disease typically presents after six months when the child starts crawling.
Von Willebrand disease presents with nosebleeds and hematomas. Idiopathic thrombocytopenic purpura presents with bruises that resemble a rash.
Glucose-6-phosphate dehydrogenase (G6PD) deficiency presents with haemolytic anaemia induced by specific drugs or foods.
Factor V Leiden mutation causes blood clotting rather than bleeding.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 98
Incorrect
-
The extensor digitorum longus is supplied by which nerve?
Your Answer:
Correct Answer: Deep peroneal nerve
Explanation:The extensor digitorum longus is innervated by the deep fibular nerve (L5, S1), a branch of the common fibular nerve.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 99
Incorrect
-
Carbamazepine is contraindicated in which of the following:
Your Answer:
Correct Answer: Atrioventricular block
Explanation:Carbamazepine is contraindicated in:
– People with known hypersensitivity to carbamazepine or structurally related drugs
– People with atrioventricular block (may suppress AV conduction and ventricular automaticity)
– People with a history of bone marrow depression (risk of agranulocytosis and aplastic anaemia)
– People with a history of acute porphyrias
– People taking a monoamine oxidase inhibitor (risk of serotonin syndrome) -
This question is part of the following fields:
- Central Nervous System
- Pharmacology
-
-
Question 100
Incorrect
-
Regarding iron deficiency anaemia, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: Dietary insufficiency is the most common cause of iron deficiency anaemia in adult men in the UK.
Explanation:Blood loss from the gastrointestinal (GI) tract is the most common cause of iron deficiency anaemia in adult men and postmenopausal women.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 101
Incorrect
-
Which of these structures is the smallest and deepest component of muscle connective tissue?
Your Answer:
Correct Answer: Endomysium
Explanation:There are three types of muscle:
Skeletal muscle
Cardiac muscle
Smooth muscleIndividual muscle is enveloped in a layer of dense irregular connective tissue called the epimysium. The epimysium protects the muscles from friction against bones and other muscles.
Skeletal muscle is composed of muscle fibres, referred to as myofibers which is ensheathed by a wispy layer of areolar connective tissue called the endomysium. The endomysium is the smallest and deepest component of muscle connective tissue.
Myofibers grouped together in bundles form fascicles, or fasciculi. These are surrounded by a type of connective tissue called the perimysium.
Beneath the endomysium lies the sarcolemma, an elastic sheath with infoldings that invaginate the interior of the myofibers, particularly at the motor endplate of the neuromuscular junction.
-
This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
-
-
Question 102
Incorrect
-
An elderly man with chronic heart and lung disease develops Legionnaires' Disease. By what route was the infection most likely to have been acquired:
Your Answer:
Correct Answer: Inhalation of aerosolised contaminated water
Explanation:Legionella pneumophilais a Gram negative bacterium that is found in natural water supplies and in the soil, transmitted predominantly via inhalation of aerosols generated from contaminated water (direct person-to-person spread of infected patients does not occur). It is the cause of Legionnaires’ disease. Outbreaks of Legionnaires’ disease have been linked to poorly maintained air conditioning systems, whirlpool spas and hot tubs.
The clinical features of the pneumonic form of Legionnaires’ disease include:
Mild flu-like prodrome for 1-3 days
Cough (usually non-productive and occurs in approximately 90%)
Pleuritic chest pain
Haemoptysis
Headache
Nausea, vomiting and diarrhoea
Anorexia
Legionella pneumophilainfections can be successfully treated with macrolide antibiotics, such as erythromycin, or quinolones, such as ciprofloxacin. Tetracyclines, such as doxycycline, can also be used.
The syndrome of inappropriate antidiuretic hormone secretion (SIADH) can occur with Legionnaires’ disease and will result in hyponatraemia as is seen in this case.
Legionella pneumophilainfections are resistant to amoxicillin but can be successfully treated with macrolide antibiotics, such as erythromycin, or quinolones, such as ciprofloxacin. Tetracyclines, such as doxycycline, can also be used. The majority of cases of Legionnaires’ disease are caused by Legionella pneumophila, however many other species of Legionella have been identified.
Legionella longbeachae is another less commonly encountered species that has also been implicated in outbreaks. It is predominantly found in soil and potting compost, and has caused outbreaks of Pontiac fever, the non-respiratory and less severe variant of Legionnaires’ disease. -
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 103
Incorrect
-
Which of the following is NOT an advantage of a case-control study used to identify past exposure to a risk factor in patients with a disease:
Your Answer:
Correct Answer: Can directly measure absolute and relative risk of a disease
Explanation:Advantages:relatively quickrelatively cheap and easy to performparticularly suitable for studying associations between an exposure and an outcome when the outcome is uncommon or if the outcome occurs decades after exposurea wide range of risk factors can be investigated in each studyDisadvantages:subject to recall biasunlike in a whole population study, absolute risk cannot be quantifiedtemporal relationship between exposure and outcome can be difficult to establishunsuitable for rare risk factorsprone to confounding
-
This question is part of the following fields:
- Evidence Based Medicine
- Study Methodology
-
-
Question 104
Incorrect
-
Intracellular [Ca2+] rise in cardiac excitation-contraction coupling is mainly as a result of:
Your Answer:
Correct Answer: Ca 2+ release from sarcoplasmic reticulum
Explanation:Although Ca2+entry during the action potential (AP) is essential for contraction, it only accounts for about 25% of the rise in intracellular Ca2+. The rest is released from Ca2+stores in the sarcoplasmic reticulum (SR). APs travel down invaginations of the sarcolemma called T-tubules, which are close to, but do not touch, the terminal cisternae of the SR. During the AP plateau, Ca2+enters the cell and activates Ca2+sensitive Ca2+release channels in the sarcoplasmic reticulum allowing stored Ca2+to flood into the cytosol; this is called Ca2+-induced Ca2+release. The amount of Ca2+released is dependent on how much is stored, and on the size of the initial Ca2+influx during the AP.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 105
Incorrect
-
Regarding cardiac excitation-contraction coupling, which of the following statements is CORRECT:
Your Answer:
Correct Answer: In relaxation, Ca 2+ is transported out of the cell using energy from a Na + gradient.
Explanation:During the AP plateau, Ca2+enters the cell and activates Ca2+sensitive Ca2+release channels in the sarcoplasmic reticulum allowing stored Ca2+to flood into the cytosol; this is called Ca2+-induced Ca2+release. In relaxation, about 80% of Ca2+is rapidly pumped back into the SR (sequestered) by Ca2+ATPase pumps. The Ca2+that entered the cell during the AP is transported out of the cell primarily by the Na+/Ca2+exchanger in the membrane which pumps one Ca2+ion out in exchange for three Na+ions in, using the Na+electrochemical gradient as an energy source. Increased heart rate increases the force of contraction in a stepwise fashion as intracellular [Ca2+] increases cumulatively over several beats; this is the Treppe effect. Factors that affect intracellular [Ca2+] and hence cardiac contractility are called inotropes.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 106
Incorrect
-
Which of the following immunoglobulins is most important for mast cell degranulation:
Your Answer:
Correct Answer: IgE
Explanation:IgA is the major Ig in secretions, particularly from the gastrointestinal tract (but also in saliva, tears, sweat and breast milk).
IgE is important for mast cell degranulation in allergic and antiparasitic response. In the allergic response, the plasma cell produces IgE-antibodies, which, like antibodies of other immunoglobulin isotypes, are capable of binding a specific allergen via its Fab portion.
IgG is the most abundant in plasma (comprising 80% of normal serum immunoglobulin) and the main circulatory Ig for the secondary immune response. -
This question is part of the following fields:
- Immune Responses
- Pathology
-
-
Question 107
Incorrect
-
Regarding haemoglobin, which of the following statements is CORRECT:
Your Answer:
Correct Answer: In degradation of haemoglobin, the haem group is split from the haemoglobin and converted to biliverdin and ultimately to bilirubin.
Explanation:Haemoglobin is composed of four polypeptide globin chains each with its own iron containing haem molecule. Haem synthesis occurs largely in the mitochondria by a series of biochemical reactions commencing with the condensation of glycine and succinyl coenzyme A under the action of the key rate-limiting enzyme delta-aminolevulinic acid (ALA) synthase. The globin chains are synthesised by ribosomes in the cytosol. Haemoglobin synthesis only occurs in immature red blood cells.
There are three types of haemoglobin in normal adult blood: haemoglobin A, A2 and F:
– Normal adult haemoglobin (HbA) makes up about 96 – 98 % of total adult haemoglobin, and consists of two alpha (α) and two beta (β) globin chains.Â
– Haemoglobin A2 (HbA2), a normal variant of adult haemoglobin, makes up about 1.5 – 3.5 % of total adult haemoglobin and consists of two α and two delta (δ) globin chains.
– Foetal haemoglobin is the main Hb in the later two-thirds of foetal life and in the newborn until approximately 12 weeks of age. Foetal haemoglobin has a higher affinity for oxygen than adult haemoglobin.Â
Red cells are destroyed by macrophages in the liver and spleen after , 120 days. The haem group is split from the haemoglobin and converted to biliverdin and then bilirubin. The iron is conserved and recycled to plasma via transferrin or stored in macrophages as ferritin and haemosiderin. An increased rate of haemoglobin breakdown results in excess bilirubin and jaundice. -
This question is part of the following fields:
- Basic Cellular
- Physiology
-
-
Question 108
Incorrect
-
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 MOSTÂ likely to be the cause?ÂYour Answer:
Correct 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
-
-
Question 109
Incorrect
-
In adult advanced life support, which of the following best describes the correct administration of adrenaline for a non-shockable rhythm:
Your Answer:
Correct Answer: Give 1 mg of adrenaline as soon as intravenous access is achieved and every 3 - 5 minutes thereafter
Explanation:IV adrenaline 1 mg (10 mL of 1:10,000 solution) should be given after 3 shocks and every 3 – 5 minutes/after alternate shocks thereafter.
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 110
Incorrect
-
Which of the following statements is correct regarding the neuronal action potential?
Your Answer:
Correct Answer: Initial depolarisation occurs as a result of a Na + influx.
Explanation:The resting potential in most neurons has a value of approximately -70 mV.
The threshold potential is generally around -55 mV.
Initial depolarisation when there is Na+influx through ligand-gated Na+channels.
Action potential is an all or nothing response. The size of the action potential is constant and so, the intensity of the stimulus is coded by the frequency of firing of a neuron.
K+efflux is responsible for repolarisation. -
This question is part of the following fields:
- Basic Cellular
- Physiology
-
-
Question 111
Incorrect
-
The term cardiac output refers to the amount of blood pumped by the heart in one minute. The rate in women is around 5 L/min, whereas in men is somewhat higher, around 5.5 L/min.
Which of the equations below best describes cardiac output?
Your Answer:
Correct Answer: Stroke volume x heart rate
Explanation:Cardiac output (CO) is calculated by multiplying stroke volume (SV) by heart rate (HR):
CO = HR x SVAs a result, both stroke volume and heart rate are exactly proportional to cardiac output. There will be an increase in cardiac output if the stroke volume or heart rate increases, and a reduction in cardiac output if the stroke volume or heart rate lowers.
-
This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
-
-
Question 112
Incorrect
-
Which of these statements about experimental studies is true?
Your Answer:
Correct Answer: Randomisation serves to remove potential bias
Explanation:In experimental studies, the researcher introduces an intervention and studies the effect. The study subjects are allocated into different groups by the investigator through the use of randomisation. Randomisation serves to remove any potential bias.
A cohort study is a form of longitudinal, observational study that follows a group of patients (the cohort) over a period of time to monitor the effects of exposure to a proposed aetiological factor upon them.
A case-control study is a type observational study. Here, patients who have developed a disease are identified and compared on the basis of proposed causative factors that occurred in the past, to a control group.
Clinical trials are experimental studies. Examples include: double blind, single blind, and unblinded studies(both patient and researcher are aware of the treatment they receive)
-
This question is part of the following fields:
- Evidence Based Medicine
-
-
Question 113
Incorrect
-
A 60-year-old man diagnosed with chronic kidney disease has an elevated creatinine level and a reduced glomerular filtration rate (GFR).
Which statement concerning glomerular filtration is true?Your Answer:
Correct Answer: Creatinine is freely filtered at the glomerulus
Explanation:Glomerular filtration is a passive process. It depends on the net hydrostatic pressure across the glomerular capillaries, the oncotic pressure, and the intrinsic permeability of the glomerulus.
The mean values for glomerular filtration rate (GFR) in young adults are 130 ml/min/1.73m2 in males and 120 ml/min/1.73m2in females.
The GFR declines with age after the age of 40 at a rate of approximately 1 ml/min/year.
The Cockcroft and Gault formula overestimates creatinine in obese patients. This is because their endogenous creatinine production is less than that predicted by overall body weight.
Creatinine is used in the estimation of GFR because it is naturally produced by muscle breakdown, not toxic, not produced by the kidney, freely filtered at the glomerulus, not reabsorbed from the nephron, and does not alter GFR.
-
This question is part of the following fields:
- Physiology
- Renal Physiology
-
-
Question 114
Incorrect
-
A 53-year-old man arrives at the emergency department complaining of visual impairment in his right eye. On examination, you notice that neither his right nor left pupil constricts when you shine a light in his right eye. When you flash a light in his left eye, the pupils of both his left and right eyes constrict. Which of the following nerves is the most likely to be affected:
Your Answer:
Correct Answer: Optic nerve
Explanation:In full optic nerve palsy, the afferent pupillary light reflex is lost. Because the afferent optic nerve does not sense light flashed in the afflicted eye, the ipsilateral direct and contralateral consensual reflexes are gone. However, the contralateral direct and ipsilateral consensual reflexes are intact because the efferent oculomotor nerve is normal.
-
This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
-
-
Question 115
Incorrect
-
A 45-year-old woman presents with persistent palpitations for the past two days. She has a good haemodynamic balance. An ECG is performed, which reveals that she has atrial flutter. The patient is examined by a cardiology registrar, who recommends using a 'rate control' strategy while she waits for cardioversion.
Which of the drugs listed below is the best fit for this strategy?Your Answer:
Correct Answer: Bisoprolol
Explanation:In atrial flutter, ventricular rate control is usually used as a stopgap measure until sinus rhythm can be restored. A beta-blocker (such as bisoprolol), diltiazem, or verapamil can be used to lower the heart rate.
Electrical cardioversion, pharmacological cardioversion, or catheter ablation can all be used to restore sinus rhythm. Cardioversion should not be attempted until the patient has been fully anticoagulated for at least three weeks if the duration of atrial flutter is unknown or has lasted for more than 48 hours. Emergency electrical cardioversion is the treatment of choice when there is an acute presentation with haemodynamic compromise. For the treatment of recurrent atrial flutter, catheter ablation is preferred.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 116
Incorrect
-
A 29 year old man presents to ED followed an alleged assault whilst out drinking. He received blunt trauma to his right axilla. He is complaining of difficulty abducting his right arm above the level of his shoulder, and on inspection, the inferior angle of his right scapula protrudes more than that of his left scapula. Which of the following nerves has most likely been affected:
Your Answer:
Correct Answer: Long thoracic nerve
Explanation:Damage to the long thoracic nerve results in weakness/paralysis of the serratus anterior muscle causing difficulty abducting the upper limb above 90 degrees and giving a ‘winged ‘ scapula appearance where the medial border, particularly the inferior angle, of the scapula moves laterally and posteriorly away from the thoracic wall (this becomes more pronounced if the patient presses the upper limb against a wall).
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 117
Incorrect
-
Regarding autoregulation of local blood flow, which of the following statements is CORRECT:
Your Answer:
Correct Answer: An increase in blood flow dilutes locally produced vasodilating factors causing vasoconstriction.
Explanation:Autoregulation is the ability to maintain a constant blood flow despite variations in blood pressure (between 50 – 170 mmHg). It is particularly important in the brain, kidney and heart. There are two main methods contributing to autoregulation:
The myogenic mechanism involves arterial constriction in response to stretching of the vessel wall, probably due to activation of smooth muscle stretch-activated Ca2+channels and Ca2+entry. A reduction in pressure and stretch closes these channels, causing vasodilation.
The second mechanism of autoregulation is due to locally produced vasodilating factors; an increase in blood flow dilutes these factors causing vasoconstriction, whereas decreased blood flow has the opposite effect. -
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 118
Incorrect
-
Regarding ciprofloxacin, which of the following statements is INCORRECT:
Your Answer:
Correct 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
-
-
Question 119
Incorrect
-
Which of the following conditions require IV Lidocaine administration?
Your Answer:
Correct Answer: Refractory ventricular fibrillation in cardiac arrest
Explanation:IV Lidocaine is indicated in Ventricular Arrhythmias or Pulseless Ventricular Tachycardia (after defibrillation, attempted CPR, and vasopressor administration)
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 120
Incorrect
-
Regarding propofol, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: A lower induction dose of propofol is required in children.
Explanation:Elderly patients have a reduced volume of distribution and slower clearance of the drug. They are therefore more sensitive to the effects of propofol and the drug wears off more slowly. They need less of the drug, which should be injected slowly, monitoring its effect on the patient. The opposite is true in children, who need larger doses of propofol. This is particularly so in children under three years of age. Propofol is not recommended for induction of anaesthesia in children under one month of age or for maintenance of anaesthesia in children under three years old.
-
This question is part of the following fields:
- Anaesthesia
- Pharmacology
-
-
Question 121
Incorrect
-
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:
Correct 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
-
-
Question 122
Incorrect
-
A 2-day-old male is referred to a tertiary care hospital by the community midwife after a home visit due to jaundice and dyspnoea. After history and examination, the relevant blood work is performed, and the baby is found to have conjugated hyperbilirubinemia. The paediatric team suspects a hepatic origin for jaundice based on the findings.
Which one of the following aetiologies is the most likely cause of jaundice in this case?Your Answer:
Correct Answer: Alpha 1-antitrypsin deficiency
Explanation:The presence of dyspnoea makes alpha-1 antitrypsin deficiency the more likely diagnosis as biliary atresia does not cause respiratory symptoms. Deficiency of the enzyme alpha-1 antitrypsin causes uninhibited elastase activity and a decrease in elastic tissue. This causes liver cirrhosis leading to an elevation of conjugated bilirubin and emphysema in the lungs.
Rhesus disease, hereditary spherocytosis and breast milk jaundice cause an elevation of unconjugated bilirubin thus ruling it out in this case. Breast milk jaundice occurs due to an inability of the newborn to metabolize the proteins in breast milk.
Rhesus disease occurs when an Rh negative mother gives birth to an Rh positive baby. The jaundice would have been accompanied by anaemia and oedema.
Hereditary spherocytosis occurs due to extravascular haemolysis as defective RBCs are removed by the spleen. The patient would present with jaundice, splenomegaly and possibly an aplastic crisis (if Parvovirus B19 infection).
-
This question is part of the following fields:
- General Pathology
- Pathology
-
-
Question 123
Incorrect
-
You examine a 43-year-old woman who was referred to you by a friend. She suffers from a variety of medical conditions and takes a variety of medications, including amitriptyline.
Which of the following is NOT a contraindication to amitriptyline treatment?Your Answer:
Correct Answer: Breastfeeding
Explanation:Amitriptyline is a tricyclic antidepressant (TCA) that is most commonly used to treat depression, but it can also be used to treat anxiety disorders, chronic pain, and attention deficit hyperactivity disorder (ADHD). It inhibits reuptake, raising serotonin and noradrenaline levels while also inhibiting acetylcholine action.
TCAs have a number of drawbacks, including:
Acute Porphyria
Arrhythmias
During bipolar disorder’s manic phase
Heart block
After a myocardial infarction, there is an immediate recovery period.TCA levels in breast milk are too low to be harmful, and use can be continued while breastfeeding.
-
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
-
-
Question 124
Incorrect
-
Regarding bicarbonate handling by the proximal tubule, which of the following statements is CORRECT:
Your Answer:
Correct Answer: For each H + secreted into the lumen, one Na + and one HCO 3 - is reabsorbed into the plasma.
Explanation:About 80% of bicarbonate is reabsorbed in the proximal tubule. HCO3-is not transported directly, tubular HCO3-associates with H+secreted by epithelial Na+/H+antiporters to form carbonic acid (H2CO3) which readily dissociates to form carbon dioxide and water in the presence of carbonic anhydrase. CO2and water diffuse into the tubular cells, where they recombine to form carbonic acid which dissociates to H+and HCO3-. This HCO3-is transported into the interstitium largely by Na+/HCO3-symporters on the basolateral membrane (and H+is secreted back into the lumen). For each H+secreted into the lumen, one Na+and one HCO3-are reabsorbed into the plasma. H+is recycled so there is little net secretion of H+at this stage.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 125
Incorrect
-
Regarding ACE inhibitors, which of the following statements is CORRECT:
Your Answer:
Correct Answer: Angiotensin-II receptor blockers are a useful alternative in patients who cannot tolerate ACE-inhibitors due a persistent cough.
Explanation:ACE inhibitors should be used with caution in patients of Afro-Caribbean descent who may respond less well; calcium channel blockers are first line for hypertension in these patients. ACE inhibitors have a role in the management of diabetic nephropathy. ACE inhibitors are contraindicated in pregnant women. ACE inhibitors inhibit the breakdown of bradykinin; this is the cause of the persistent dry cough. Blocking ACE also diminishes the breakdown of the potent vasodilator bradykinin which is the cause of the persistent dry cough. Angiotensin-II receptor blockers do not have this effect, therefore they are useful alternative for patients who have to discontinue an ACE inhibitor because of persistent cough.
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 126
Incorrect
-
Which one of these infectious diseases typically has an incubation period of between 1 and 3 weeks?
Your Answer:
Correct Answer: Chickenpox
Explanation:The incubation period for Chickenpox is 7-23 days (usually around 2 weeks).
Incubation period of botulism is 18-36 hours
Incubation period of Meningococcaemia is 1-7 days.
Incubation period of Gonorrhoea is 3-5 days.
Incubation period of Hepatitis A is 3-5 weeks.
Other infectious with an incubation period of between 1 and 3 weeks are:
Whooping cough (7-10 days)
Brucellosis (7-21 days)
Leptospirosis (7-12 days)
Malaria (7-40 days depending on strain)
Typhoid (8-21 days)
Measles (10-18 days)
Mumps (14-18 days)
Rubella (14-21 days) -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 127
Incorrect
-
A patient is diagnosed with a Klebsiella infection.
Which SINGLE statement regarding Klebsiella infections is true?Your Answer:
Correct Answer: Klebsiella spp are an important cause of ventilator-associated pneumonia
Explanation:Klebsiellais a genus of non-motile,Gram-negative, rod-shaped bacteriawith a prominent polysaccharide-based capsule. They are routinely found in the nose, mouth and gastrointestinal tract as normal flora, however, they can also behave as opportunistic pathogens.
Infections with Klebsiella spp. areusually nosocomial. They are an important cause of ventilator-associated pneumonia (VAP), urinary tract infection, wound infection and bacteraemia. Outbreaks of infections with Klebsiellaspp. in high-dependency units have been described and are associated with septicaemia and high mortality rates. Length of hospital stay and performance of invasive procedures are risk factors forKlebsiellainfections.
Primary pneumonia withKlebsiella pneumoniaeis a rare,severe, community-acquired infection associated with a poor outcome.
Klebsiella rhinoscleromatis causes a progressive granulomatous infection of the nasal passages and surrounding mucous membranes. This infection is mainly seen in the tropics.
Klebsiella ozanae is a recognised cause of chronic bronchiectasis.
Klebsiella organisms are resistant to multiple antibiotics including penicillins. This is thought to be a plasmid-mediated property. Agents with high intrinsic activity againstKlebsiellapneumoniaeshould be selected for severely ill patients. Examples of such agents include third-generation cephalosporins (e.g cefotaxime), carbapenems (e.g. imipenem), aminoglycosides (e.g. gentamicin), and quinolones (e.g. ciprofloxacin). These agents may be used as monotherapy or combination therapy. Aztreonam may be used in patients who are allergic to beta-lactam antibiotics.
Species with ESBLs (Extended spectrum beta-lactamase) are resistant to penicillins and also cephalosporins such as cefotaxime and ceftriaxone
. -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 128
Incorrect
-
A 32-old woman comes for a follow-up visit after being discharged on medications for her newly diagnosed epilepsy. She now complains of a tremor in her arm when she holds a tray in her hand. You examine the patient and notice she has developed postural tremors.
Which of the following medications for epilepsy is most likely responsible for this tremor?Your Answer:
Correct Answer: Sodium valproate
Explanation:A postural tumour is observed when a person maintains a position against gravity, such as holding the arms outstretched. (The patient holding her tray against gravity)
Sodium valproate is the most commonly prescribed medication for epilepsy. It is commonly associated with tremors as valproate-induced tremors occur in around 6-45% of patients. The tremors are commonly postural, but a resting tremor may also occur.
Approximately 25% of patients taking sodium valproate are found to develop a tremor within 3-12 months of initiating therapy.
-
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
-
-
Question 129
Incorrect
-
A 2nd-year medical student is solving an exam paper with questions about the immune system. She comes across a question regarding innate immunity. Innate immunity is the immunity naturally present within the body from birth.
Which ONE of the following is not a part of this type of immunity?Your Answer:
Correct Answer: Antibody production
Explanation:Innate immunity, also called non-specific immunity, refers to the components of the immune system naturally present in the body at birth.
The components of innate immunity include:
1) Natural Killer Cells
2) Neutrophils
3) Macrophages
4) Mast Cells
5) Dendritic Cells
6) Basophils.Acquired or adaptive immunity is acquired in response to infection or vaccination. Although the response takes longer to develop, it is also a more long-lasting form of immunity.
The components of this system include:
1) T lymphocytes
2) B lymphocytes
3) Antibodies -
This question is part of the following fields:
- General Pathology
- Pathology
-
-
Question 130
Incorrect
-
A patient suffers a stab wound to the neck. The entry point of the blade is situated within the posterior triangle of the neck.
Which of the following muscles is most likely to be involved? Select ONE answer only.Your Answer:
Correct Answer: Anterior scalene
Explanation:The anterior triangle is the triangular area of the neck found anteriorly to the sternocleidomastoid muscle. It is formed by the anterior border of sternocleidomastoid laterally, the median line of the neck medially and by the inferior border of the mandible superiorly. The apex of the anterior triangle extends towards the manubrium sterni. The anterior triangle contains:
Muscles: thyrohyoid, sternothyroid, sternohyoid muscles
Organs: thyroid gland, parathyroid glands, larynx, trachea, esophagus, submandibular gland, caudal part of the parotid gland
Arteries: superior and inferior thyroid, common carotid, external carotid, internal carotid artery (and sinus), facial, submental, lingual arteries
Veins: anterior jugular veins, internal jugular, common facial, lingual, superior thyroid, middle thyroid veins, facial vein, submental vein, lingual veins
Nerves: vagus nerve (CN X), hypoglossal nerve (CN XII), part of sympathetic trunk, mylohyoid nerveThe posterior triangle is a triangular area found posteriorly to the sternocleidomastoid muscle. It has three borders; anterior, posterior and inferior borders. The anterior border is the posterior margin of the sternocleidomastoid muscle. The posterior border is the anterior margin of the trapezius muscle, while the inferior border is the middle one-third of the clavicle. The investing layer of deep cervical fascia and integument forms the roof of the space, while the floor is covered with the prevertebral fascia along with levator scapulae, splenius capitis and the scalene muscles. The inferior belly of omohyoid subdivides the posterior triangle into a small supraclavicular, and a large occipital, triangle.
Contents:
Vessels: the third part of the subclavian artery, suprascapular and transverse cervical branches of the thyrocervical trunk, external jugular vein, lymph nodes
Nerves: accessory nerve (CN XI), the trunks of the brachial plexus, fibers of the cervical plexus
Of the muscles listed in the options, only the anterior scalene is situated within the posterior triangle of the neck. -
This question is part of the following fields:
- Anatomy
- Head And Neck
-
-
Question 131
Incorrect
-
Which of the following infections is vancomycin most likely prescribed for?
Your Answer:
Correct Answer: Clostridium difficile colitis
Explanation:125 mg PO q6hr for 10 days is indicated for treatment of Clostridium difficile (C. difficile)-associated diarrhoea
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 132
Incorrect
-
All of the following statements regarding metronidazole are correct except:
Your Answer:
Correct Answer: Metronidazole reduces the anticoagulant effect of warfarin.
Explanation:The anticoagulant effect of warfarin is enhanced by metronidazole. If use of both cannot be avoided, one must consider appropriately reducing the warfarin dosage. With alcohol, metronidazole can cause a disulfiram-like reaction, with symptoms like flushing, headaches, dizziness, tachypnoea and tachycardia, nausea and vomiting. The common side effects of metronidazole include a metallic taste and gastrointestinal irritation, in particular nausea and vomiting. These side effects are more common at higher doses. This drug has high activity against anaerobic bacteria and protozoa, and is well absorbed orally. For severe infections, the intravenous route is normally reserved.
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 133
Incorrect
-
A 63 year old lady presents to ED with a persistent cough and red currant jelly sputum. She has a history of chronic alcohol abuse and has an X-ray which demonstrates a cavitating pneumonia. The most likely causative pathogen is:
Your Answer:
Correct Answer: Klebsiella pneumoniae
Explanation:One of the results of Klebsiella pneumoniae is pneumonia that is usually a very severe infection. It is characterised by thick, bloody sputum (red currant jelly sputum), and is associated with complications like lung abscess, cavitation, necrosis, empyema and pleural effusions.
-
This question is part of the following fields:
- Infections
- Microbiology
-
-
Question 134
Incorrect
-
You are reviewing a patient complaining of loss of vision. Previous images shows a lesion at the optic chiasm. What type of visual field defect are you most likely to see in a lesion at the optic chiasm:
Your Answer:
Correct Answer: Bitemporal hemianopia
Explanation:A lesion at the optic chiasm will result in a bitemporal hemianopia.
A lesion of the optic nerve will result in ipsilateral monocular visual loss.
A lesion of the optic tract will result in a contralateral homonymous hemianopia. -
This question is part of the following fields:
- Anatomy
- Central Nervous System
-
-
Question 135
Incorrect
-
Which of these drugs may reduce the efficacy of contraception?
Your Answer:
Correct Answer: Carbamazepine
Explanation:Antiepileptic medications such as carbamazepine (Tegretol), topiramate (Topamax), and phenytoin (Dilantin) are widely known for reducing the contraceptive effectiveness of OCPs.
-
This question is part of the following fields:
- Central Nervous System
- Pharmacology
-
-
Question 136
Incorrect
-
Noradrenaline exhibits its positive inotropic effect by which of the following mechanisms:
Your Answer:
Correct Answer: Binds to beta1-receptors and causes increased Ca2+ entry via L-type channels during the action potential
Explanation:Noradrenaline (the sympathetic neurotransmitter) is a positive inotrope; it binds to β1-adrenoceptors on the membrane and causes increased Ca2+entry via L-type channels during the AP and thus increases Ca2+release from the SR. Noradrenaline also increases Ca2+sequestration into the SR and thus more Ca2+is available for the next contraction. Cardiac glycosides (e.g. digoxin) slow the removal of Ca2+from the cell by inhibiting the membrane Na+pump which generates the Na+gradient required for driving the export of Ca2+; consequently the removal of Ca2+from the myocyte is slowed and more Ca2+is available for the next contraction. Acidosis is negatively inotropic, largely because H+competes for Ca2+binding sites.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 137
Incorrect
-
All of the following are actions of insulin except:
Your Answer:
Correct Answer: Increased gluconeogenesis
Explanation:Major Actions of Insulin:
↑ Glucose uptake into cells
↑ Glycogenesis
↓ Glycogenolysis
↓ Gluconeogenesis
↑ Protein synthesis
↓ Protein degradation
↑ Fat deposition
↓ Lipolysis
↓ Ketoacid production
↑ K+ uptake into cellsMajor Actions of Glucagon:
↓ Glycogenesis
↑ Glycogenolysis
↑ Gluconeogenesis
↓ Fatty acid synthesis
↑ Lipolysis
↑ Ketoacid production -
This question is part of the following fields:
- Endocrine
- Physiology
-
-
Question 138
Incorrect
-
A 28-year-old patient is intubated and has a central venous catheter inserted after being diagnosed with septic shock. You keep track of her central venous pressure.
The normal value for central venous pressure is which of the following?Your Answer:
Correct Answer: 0-8 cmH 2 O
Explanation:The pressure measured in the right atrium or superior vena cava is known as central venous pressure (CVP). In a spontaneously breathing subject, the usual CVP value is 0-8 cmH2O (0-6 mmHg).
At the conclusion of expiration, the CVP should be measured with the patient resting flat. The catheter’s tip should be at the intersection of the superior vena cava and the right atrium. An electronic transducer is installed and zeroed at the level of the right atrium to measure it (usually in the 4th intercostal space in the mid-axillary line).
CVP is a good predictor of preload in the right ventricle. Hypovolaemia is indicated by a volume challenge of 250-500 mL crystalloid eliciting an increase in CVP that is not sustained for more than 10 minutes.CVP is influenced by a number of factors, including:
Mechanical ventilation (and PEEP)
Pulmonary hypertension
Pulmonary embolism
Heart failure
Pleural effusion
Decreased cardiac output
Cardiac tamponade
CVP is reduced by the following factors:
Distributive shock
Negative pressure ventilation
Hypovolaemia
Deep inhalation -
This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
-
-
Question 139
Incorrect
-
Gastric emptying is increased by all of the following EXCEPT for:
Your Answer:
Correct Answer: Secretin
Explanation:Gastric emptying is increased by:
Distension of the pyloric antrum
A fall in the pH of chyme in the stomach
Parasympathetic stimulation (via vagus)
Gastrin
The hormones secretin, cholecystokinin and gastric inhibitory polypeptide (GIP) inhibit gastric emptying. -
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
-
Question 140
Incorrect
-
A 45-year-old African American male presents to your clinic complaining of swelling of his feet for the past six months. On examination, there is periorbital and pedal oedema. A 24-hour urine collection is ordered, which shows 8 g of protein. The serum cholesterol is ten mmol/L. You order a renal biopsy to confirm the diagnosis.
Which one of the following findings are you most likely to see in this patient's biopsy?Your Answer:
Correct Answer: Focal segmental glomerulosclerosis
Explanation:This patient has Nephrotic Syndrome confirmed by the presence of 1. Heavy proteinuria (greater than 3-3.5 g/24 hours)
2. Hypoalbuminemia (serum albumin < 25 g/L)
3. Generalised oedema (often with periorbital involvement)
4. Severe hyperlipidaemia (total cholesterol is often > 10 mmol/L).Focal Segmental Glomerulosclerosis will be the most likely answer as it is the most common cause of Nephrotic Syndrome in African American adults.
Minimal change disease is the most common cause of nephrotic syndrome in children.
Membranous glomerulonephritis is the most common cause of Nephrotic Syndrome in Caucasian adults.
In IgA nephropathy, patients will complain of cola-coloured urine.
Mesangiocapillary glomerulonephritis presents with features of Nephritic Syndrome.
-
This question is part of the following fields:
- General Pathology
- Pathology
-
-
Question 141
Incorrect
-
You need to give your patient antibiotics, so you call microbiology for some advice.
Of the following antibacterial drugs, which of them is a protein synthesis inhibitor?
Your Answer:
Correct Answer: Erythromycin
Explanation:Bacteriostatic antibiotics include erythromycin and other macrolides. They work by attaching to the bacterial ribosome’s 50S subunit, preventing translocation and, as a result, inhibit protein synthesis. Macrolide antibiotics are actively concentrated inside leukocytes and delivered into the infection site as a result.
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 142
Incorrect
-
A patient suffers a stab wound to the neck. The entry point of the blade is situated within the anterior triangle of the neck.
Which of the following muscles is most likely to be involved? Select ONE answer only.Your Answer:
Correct Answer: Sternohyoid
Explanation:The anterior triangle is the triangular area of the neck found anteriorly to the sternocleidomastoid muscle. It is formed by the anterior border of sternocleidomastoid laterally, the median line of the neck medially and by the inferior border of the mandible superiorly. The apex of the anterior triangle extends towards the manubrium sterni. The anterior triangle contains:
Muscles: thyrohyoid, sternothyroid, sternohyoid muscles
Organs: thyroid gland, parathyroid glands, larynx, trachea, esophagus, submandibular gland, caudal part of the parotid gland
Arteries: superior and inferior thyroid, common carotid, external carotid, internal carotid artery (and sinus), facial, submental, lingual arteries
Veins: anterior jugular veins, internal jugular, common facial, lingual, superior thyroid, middle thyroid veins, facial vein, submental vein, lingual veins
Nerves: vagus nerve (CN X), hypoglossal nerve (CN XII), part of sympathetic trunk, mylohyoid nerveThe posterior triangle is a triangular area found posteriorly to the sternocleidomastoid muscle. It has three borders; anterior, posterior and inferior borders. The anterior border is the posterior margin of the sternocleidomastoid muscle. The posterior border is the anterior margin of the trapezius muscle, while the inferior border is the middle one-third of the clavicle. The investing layer of deep cervical fascia and integument forms the roof of the space, while the floor is covered with the prevertebral fascia along with levator scapulae, splenius capitis and the scalene muscles. The inferior belly of omohyoid subdivides the posterior triangle into a small supraclavicular, and a large occipital, triangle.
Contents:
Vessels: the third part of the subclavian artery, suprascapular and transverse cervical branches of the thyrocervical trunk, external jugular vein, lymph nodes
Nerves: accessory nerve (CN XI), the trunks of the brachial plexus, fibers of the cervical plexus -
This question is part of the following fields:
- Anatomy
- Head And Neck
-
-
Question 143
Incorrect
-
Swelling of the lips, tongue, and face is observed in a 59-year-old African-American woman. In the emergency room, she is given intramuscular adrenaline, but her symptoms do not improve. Her GP recently started her on a new medication.
Which of the following drugs is most likely to have caused her symptoms?Your Answer:
Correct Answer: Ramipril
Explanation:Angiotensin-converting enzyme (ACE) inhibitors are the most common cause of drug-induced angioedema in the United Kingdom and the United States, owing to their widespread use.
Angioedema is caused by ACE inhibitors in 0.1 to 0.7 percent of patients, with data indicating a persistent and relatively constant risk year after year. People of African descent have a five-fold higher chance of contracting the disease.
Swelling of the lips, tongue, or face is the most common symptom, but another symptom is episodic abdominal pain due to intestinal angioedema. Itching and urticaria are noticeably absent.
The mechanism appears to be activated complement or other pro-inflammatory cytokines like prostaglandins and histamine, which cause rapid vasodilation and oedema.
Other medications that are less frequently linked to angioedema include:
Angiotensin-receptor blockers (ARBs)
Nonsteroidal anti-inflammatory drugs (NSAIDs)
Bupropion (e.g. Zyban and Wellbutrin)
Beta-lactam antibiotics
Statins
Proton pump inhibitorsThe majority of these reactions are minor and can be treated by stopping the drug and prescribing antihistamines.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 144
Incorrect
-
Regarding loop diuretics, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: The risk of hypokalaemia is greater with loop diuretics than with an equipotent dose of a thiazide diuretic.
Explanation:Hypokalaemia can occur with both thiazide and loop diuretics. The risk of hypokalaemia depends on the duration of action as well as the potency and is thus greater with thiazides than with an equipotent dose of a loop diuretic. Hypokalaemia is dangerous in severe cardiovascular disease and in patients also being treated with cardiac glycosides. Often the use of potassium-sparing diuretics avoids the need to take potassium supplements. In hepatic failure, hypokalaemia caused by diuretics can precipitate encephalopathy, particularly in alcoholic cirrhosis.
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 145
Incorrect
-
Identify the type of graph described below:
A graph that is a useful summary of a set of bivariate data (two variables), usually drawn before working out a linear correlation coefficient or fitting a regression line.Your Answer:
Correct Answer: Scatterplot
Explanation:A scatterplot is a useful summary of a set of bivariate data (two variables), usually drawn before working out a linear correlation coefficient or fitting a regression line. It gives a good visual picture of the relationship between the two variables, and aids the interpretation of the correlation coefficient or regression model. Each unit contributes one point to the scatterplot, on which points are plotted but not joined. The resulting pattern indicates the type and strength of the relationship between the two variables.
-
This question is part of the following fields:
- Evidence Based Medicine
-
-
Question 146
Incorrect
-
A patient presents with severe vomiting. They take a maintenance dose of 12.5 mg of prednisolone daily for their COPD. They are unable to swallow or keep down tablets at present, and you plan on converting them to IV hydrocortisone.
What dose of hydrocortisone is equivalent to this dose of prednisolone? Select ONE answer only.Your Answer:
Correct Answer: 50 mg
Explanation:Prednisolone is four times more potent than hydrocortisone, and therefore, a dose of 12.5 mg would be equivalent to 50 mg of hydrocortisone.
The following table summarises the relative potency of the main corticosteroids compared with hydrocortisone:
Corticosteroid
Potency relative to hydrocortisone
Prednisolone
4 times more potent
Triamcinolone
5 times more potent
Methylprednisolone
5 times more potent
Dexamethasone
25 times more potent -
This question is part of the following fields:
- Endocrine Pharmacology
- Pharmacology
-
-
Question 147
Incorrect
-
Approximately what proportion of lymphocytes are B-cells:
Your Answer:
Correct Answer: 0.2
Explanation:B-cells (20% of lymphocytes) mature in the bone marrow and circulate in the peripheral blood until they undergo recognition of antigen. B-cell immunoglobulin molecules synthesised in the cell are exported and bound to the surface membrane to become the B-cell receptor (BCR) which can recognise and bind to a specific antigen (either free or presented by APCs). The BCR is also important for antigen internalisation, processing and presentation to T helper cells. Most antibody responses require help from antigen-specific T helper cells (although some antigens such as polysaccharide can lead to T-cell independent B-cell antibody production). When the B-cell is activated, the receptor itself is secreted as free soluble immunoglobulin and the B-cell matures into a memory B-cell or a plasma cell (a B-cell in its high-rate immunoglobulin secreting state). Plasma cells are non-motile and are found predominantly in the bone marrow or spleen. Most plasma cells are short-lived (1 – 2 weeks) but some may survive much longer. A proportion of B-cells persist as memory cells, whose increased number and rapid response underlies the augmented secondary response of the adaptive immune system.
-
This question is part of the following fields:
- Immune Responses
- Pathology
-
-
Question 148
Incorrect
-
A patient has an elevated potassium level of 6.7 mmol/L. All of the following conditions may cause elevated potassium levels, except for which one?
Your Answer:
Correct Answer: Bartter’s syndrome
Explanation:Bartter’s syndrome is an autosomal recessive renal tubular disorder characterized by hypokalaemia, hypochloraemia, metabolic alkalosis, and hyperreninemia with normal blood pressure. The underlying kidney abnormality results in excessive urinary losses of sodium, chloride, and potassium.
Bartter’s syndrome does not cause an elevated potassium level, but instead causes a decrease in its concentration (hypokalaemia). The other choices are causes of hyperkalaemia or elevated potassium levels.
Renal failure, Addison’s disease (adrenal insufficiency), congenital adrenal hyperplasia, renal tubular acidosis (type 4), rhabdomyolysis, burns and trauma, tumour syndrome, and acidosis are non-drug causes of hyperkalaemia. On the other hand, drugs that can cause hyperkalaemia include ACE inhibitors, angiotensin receptor blockers, NSAIDs, beta-blockers, digoxin, and suxamethonium.
-
This question is part of the following fields:
- Physiology
- Renal Physiology
-
-
Question 149
Incorrect
-
A 27-year-old man has been diagnosed with testicular cancer and has spread to the regional lymph nodes.
The lymph from the testes will drain to which of the following nodes?Your Answer:
Correct Answer: Para-aortic lymph nodes
Explanation:Testes are retroperitoneal organs and its lymphatic drainage is to the lumbar and para-aortic nodes along the lumbar vertebrae.
The scrotum is the one which drains into the nearby superficial inguinal nodes.
The glans penis and clitoris drains into the deep inguinal lymph nodes.
-
This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
-
-
Question 150
Incorrect
-
Which anatomical structure is divided following an emergency department anterolateral thoracotomy?
Your Answer:
Correct Answer: Latissimus dorsi
Explanation:Thoracotomy describes an incision made in the chest wall to access the contents of the thoracic cavity. Thoracotomies typically can be divided into two categories; anterolateral thoracotomies and posterolateral thoracotomies. These can be further subdivided into supra-mammary and infra-mammary and, of course, further divided into the right or left chest. Each type of incision has its utility given certain circumstances.
A scalpel is used to sharply divide the skin along the inframammary crease overlying the fifth rib. Electrocautery is then used to divide the pectoralis major muscle and serratus anterior muscle. Visualization of the proper operative field can be achieved with the division and retraction of the latissimus dorsi. Either the fourth or fifth intercostal space is then entered after the division of intercostal muscles above the rib to ensure the preservation of the neurovascular bundle. Once the patient is properly secured to the operating table, the ipsilateral arm is raised and positioned anteriorly and cephalad to rest above the head. The incision is started along the inframammary crease and extended posterolaterally below the tip of the scapula. It is then extended superiorly between the spine and the edge of the scapula, a short distance. The trapezius muscle and the subcutaneous tissues are divided with electrocautery. The serratus anterior and latissimus dorsi muscles are identified and can be retracted. The intercostal muscles are then divided along the superior border of the ribs, and the thoracic cavity is accessed.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 151
Incorrect
-
A 24-year-old waiter cuts his hand on a dropped plate that smashed and damages the nerve that innervates opponens digiti minimi.
The opponens digiti minimi muscle is innervated by which of the following nerves? Select ONE answer only.Your Answer:
Correct Answer: The deep branch of the ulnar nerve
Explanation:Opponens digiti minimi is a triangular-shaped muscle in the hand that forms part of the hypothenar eminence. It originates from the hook of the hamate bone and the flexor retinaculum and inserts into the medial border of the 5thmetacarpal.
Opponens digiti minimi is innervated by the deep branch of the ulnar nerve and receives its blood supply from the ulnar artery.
Opponens digiti minimi draws the fifth metacarpal bone anteriorly and rotates it, bringing the fifth digiti into opposition with the thumb. -
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 152
Incorrect
-
A patient presents with nausea, anorexia, jaundice and right upper quadrant pain. A diagnosis of acute hepatitis B is suspected.
Which of the following blood results is most suggestive of an acute hepatitis B infection? Select ONE answer only.Your Answer:
Correct Answer: HBsAg positive, IgM anti-HBc positive
Explanation:Hepatitis B surface antigen (HBsAg) is a protein on the surface of the hepatitis B virus, that is the first serologic marker to appear in a new acute infection.It can be detected as early as 1 week and as late as 9 weeks. It can be detected in high levels in serum during acute or chronic hepatitis B virus infection. The presence of HBsAg indicates that the person is infectious. The body normally produces antibodies to HBsAg as part of the normal immune response to infection. HBsAg is the antigen used to make hepatitis B vaccine.
Hepatitis B surface antibody (anti-HBs) indicates recovery and immunity from the hepatitis B virus infection. Anti-HBs also develops in a person who has been successfully vaccinated against hepatitis B.
Total hepatitis B core antibody (anti-HBc): Appears at the onset of symptoms in acute hepatitis B and persists for life. The presence of anti-HBc indicates previous or ongoing infection with hepatitis B virus in an undefined time frame. It is not present following hepatitis B vaccination.
IgM antibody to hepatitis B core antigen (IgM anti-HBc) indicates recent infection with hepatitis B virus (<6 months). Its presence indicates acute infection.
The following table summarises the presence of hepatitis B markers according to each situation:
Susceptible to infection:
HBsAg = Negative
Anti-HBc = Negative
Anti-HBs = NegativeImmune due to natural infection:
HBsAg = Negative
Anti-HBc = Positive
Anti-HBs = PositiveImmune due to vaccination:
HBsAg = Negative
Anti-HBc = Negative
Anti-HBs = PositiveAcute infection:
HBsAg = Positive
Anti-HBc = Positive
Anti-HBs = Negative
IgM anti-HBc = PositiveChronic infection:
HBsAg = Positive
Anti-HBc = Positive
Anti-HBs = Negative
IgM anti-HBc = Negative -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 153
Incorrect
-
Which of the following is the site of secretion of intrinsic factor:
Your Answer:
Correct Answer: Stomach
Explanation:Intrinsic factor is essential for the absorption of the small amounts of vitamin B12 normally present in the diet from the terminal ileum. The parietal cells of the stomach produce intrinsic factor, and following a gastrectomy, the absorption of vitamin B12 will be markedly reduced, and a deficiency state will exist.
-
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
-
Question 154
Incorrect
-
The following statements about cross-sectional studies are true EXCEPT?
Your Answer:
Correct Answer: They can be used to determine the relative risk of a condition
Explanation:The UK national census is an example of a cross-sectional study.
Cross-sectional studies can be used to assess the prevalence of a condition, and support or refute inferences of cause and effect.
Cross-sectional studies are observations of the frequency and characteristics of a disease in a given population at one particular point in time.
Cross-sectional studies do not differentiate between cause and effect and also do not establish the sequence of events.
Cross-sectional studies cannot be used to calculate the relative risk of a condition.
-
This question is part of the following fields:
- Evidence Based Medicine
-
-
Question 155
Incorrect
-
Cryptococcus neoformans is primarily transmitted by which of the following routes:
Your Answer:
Correct Answer: Inhalation of spores
Explanation:Cryptococcus neoformans is found in bird droppings and transmission is by inhalation of spores, thus the lung is the primary site of infection.
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 156
Incorrect
-
Approximately what percentage of filtered bicarbonate is reabsorbed in the proximal tubule:
Your Answer:
Correct Answer: 80%
Explanation:Bicarbonate is freely filtered at the glomerulus. Less than 0.1% of filtered bicarbonate is normally excreted in the urine (if plasma [HCO3-] increases, maximum tubular transport is exceeded and some HCO3-is excreted in urine). About 80% of bicarbonate is reabsorbed in the proximal tubule. For each H+secreted into the lumen, one Na+and one HCO3-are reabsorbed into the plasma. H+is recycled so there is little net secretion of H+at this stage. A further 10 – 15% of HCO3-is similarly reabsorbed in the thick ascending limb of the loop of Henle. In the early distal tubule, H+secretion is predominantly by Na+/H+exchange but more distally, the Na+gradient is insufficient so secretion is via H+ATPase and H+/K+ATPase in intercalated cells, which contain plentiful carbonic acid.
As secreted H+is derived from CO2, new HCO3-is formed and returns to the blood.H+secretion is proportional to intracellular [H+] which itself is related to extracellular pH. A fall in blood pH will therefore stimulate renal H+secretion. In the proximal tubule secretion of H+serves to reclaim bicarbonate from glomerular filtrate so it is not lost, but in the distal nephron, secretion leads to net acid excretion and generation of new bicarbonate.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 157
Incorrect
-
All of the following statement are correct regarding endothelium derived nitric oxide except:
Your Answer:
Correct Answer: Nitric oxide production is inhibited by local mediators such as bradykinin, histamine and serotonin.
Explanation:Factors that elevate intracellular Ca2+ increase nitric oxide (NO) production by the endothelium included local mediators such as histamine and serotonin, bradykinin, and some neurotransmitters like substance P. NO production is also stimulated by increased flow (shear stress) and additionally activates prostacyclin synthesis. As a result of basal production of NO, there is continuous modulation of vascular resistance and as a result, there is increased production of nitric oxide acts which causes vasodilation. Platelet activation and thrombosis are inhibited by nitric oxide.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 158
Incorrect
-
Regarding the resting membrane potential, which of the following statements is CORRECT:
Your Answer:
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
-
-
Question 159
Incorrect
-
Which of the following does NOT predispose to digoxin toxicity in a patient taking digoxin:
Your Answer:
Correct Answer: Hyponatraemia
Explanation:Hypoxia, hypercalcaemia, hypokalaemia and hypomagnesaemia predispose to digoxin toxicity. Care should also be taken in the elderly who are particularly susceptible to digoxin toxicity. Hypokalaemia may be precipitated by use of diuretics. Although hyponatremia can result in the development of other pathological disturbances, it does not potentiate digoxin toxicity.
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 160
Incorrect
-
In ventricular myocytes, the plateau phase of the action potential comes about through which of the following:
Your Answer:
Correct Answer: Opening of voltage-gated Ca 2+ channels
Explanation:After the intial upstroke of the action potential, Na+channels and currents rapidly inactivate, but in cardiac myocytes, the initial depolarisation activates voltage-gated Ca2+channels (slow L-type channels, threshold approximately – 45 mV) through which Ca2+floods into the cell. The resulting influx of Ca2+prevents the cell from repolarising and causes a plateau phase, that is maintained for about 250 ms until the L-type channels inactivate. The cardiac AP is thus much longer than that in nerve or skeletal muscle.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 161
Incorrect
-
A 35 year old man presents with a deep laceration to the proximal part of the forearm. On further assessment, the patient is unable to flex the metacarpophalangeal joints and interphalangeal joints of the index, middle finger and the thumb.
The ring and little fingers are intact but there is weakness at the proximal interphalangeal joint.
There is also loss of sensation over the lateral palm and the palmar surface of the lateral three and a half fingers.
Which of these nerve(s) has most likely been affected?
Your Answer:
Correct Answer: Median nerve
Explanation:A median nerve injury affecting the extrinsic and intrinsic muscles of the hand will present with:
Loss of sensation to the lateral palm and the lateral three and a half fingers.
Weakness of flexion at the metacarpophalangeal joints of the index and middle finger. This is because of paralysis of the lateral two lumbricals.
Weakness of flexion of the proximal interphalangeal joints of all four fingers due to paralysis of the flexor digitorum superficialis
Weakness of flexion at the distal interphalangeal joints of the index and middle finger following paralysis of the lateral half of the flexor digitorum profundus.
Weakness of thumb flexion, abduction and opposition due to paralysis of the flexor pollicis longus and thenar muscles -
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 162
Incorrect
-
Regarding forest plots, which of the following is the purpose of this graph?
Your Answer:
Correct Answer: To graphically display the relative strength of multiple studies attempting to answer the same question
Explanation:The results of meta-analysis are often displayed graphically in a forest plot. A properly constructed forest plot is the most effective way to graphically display the relative strength of multiple studies attempting to answer the same question. A typical meta-analysis consists of three main objectives that include estimation of effect sizes from individual studies and a pooled summary estimate with their confidence intervals (CIs), heterogeneity among the studies, and any publication bias. The forest plot illustrates the first two of these objectives. Forest plots visualize the effect measure and CI of individual studies, which provide the raw data for the meta-analysis, as well the pooled-effect measure and CI. The individual studies also can be grouped in the forest plot by some of their characteristics for ease of interpretation such as by study size or year of publication. When comparing the outcomes between an intervention and a control group, dichotomous outcome variables are expressed as ratios (i.e. odds ratios, ORs or risk ratios, RRs), while for continuous outcomes, a weighted mean difference is reported.
-
This question is part of the following fields:
- Evidence Based Medicine
-
-
Question 163
Incorrect
-
Salivary glands produce saliva which is mostly water, but it also contains a range of essential chemicals such as mucus, electrolytes, antibiotic agents, and enzymes.
Which of the following is a carbohydrate-digesting enzyme found in saliva?
Your Answer:
Correct Answer: Amylase
Explanation:The acinar cells of the parotid and submandibular glands release amylase. Amylase begins starch digestion before food is even eaten, and it works best at a pH of 7.4.
-
This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
-
-
Question 164
Incorrect
-
You examine a child who has been admitted to the paediatric emergency department with a flu-like illness. His parents tell you that he was born with an inborn defect of steroid metabolism and that he was treated for it with hormone replacement therapy.
Which of the following is classified as a steroid hormone?
Your Answer:
Correct Answer: Aldosterone
Explanation:Hormones can be classified into three categories depending on their chemical composition: amines, peptides (and proteins), and steroids. Amines are made up of single amino acids (for example, tyrosine), peptide hormones are made up of peptides (or proteins), and steroid hormones are made up of cholesterol.
The table below lists some prominent instances of each of these three hormone classes:1. Peptide hormone:
Adrenocorticotropic hormone (ACTH)
Prolactin
Vasopressin
Oxytocin
Glucagon
Insulin
Somatostatin
Cholecystokinin2. Amine hormone:
Adrenaline (epinephrine)
Noradrenaline (norepinephrine)
Dopamine3. Steroid hormone:
Mineralocorticoids (e.g. aldosterone)
Glucocorticoids (e.g. cortisol)
Progestogens
Androgens
Oestrogens -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
-
-
Question 165
Incorrect
-
Which of the following is considered an example of an observational study?
Your Answer:
Correct Answer: Cohort study
Explanation:The two most common types of observational studies are cohort studies and case-control studies; a third type is cross-sectional studies.
-
This question is part of the following fields:
- Evidence Based Medicine
-
-
Question 166
Incorrect
-
Regarding Legionella species which of the following statements is CORRECT:
Your Answer:
Correct Answer: They are Gram-negative organisms.
Explanation:Legionella pneumophilais a Gram negative bacterium that is found in natural water supplies and in the soil, transmitted predominantly via inhalation of aerosols generated from contaminated water (direct person-to-person spread of infected patients does not occur). It is the cause of Legionnaires’ disease. Outbreaks of Legionnaires’ disease have been linked to poorly maintained air conditioning systems, whirlpool spas and hot tubs.
The clinical features of the pneumonic form of Legionnaires’ disease include:
Mild flu-like prodrome for 1-3 days
Cough (usually non-productive and occurs in approximately 90%)
Pleuritic chest pain
Haemoptysis
Headache
Nausea, vomiting and diarrhoea
Anorexia
Legionella pneumophilainfections can be successfully treated with macrolide antibiotics, such as erythromycin, or quinolones, such as ciprofloxacin. Tetracyclines, such as doxycycline, can also be used.
The syndrome of inappropriate antidiuretic hormone secretion (SIADH) can occur with Legionnaires’ disease and will result in hyponatraemia as is seen in this case.
Legionella pneumophilainfections are resistant to amoxicillin but can be successfully treated with macrolide antibiotics, such as erythromycin, or quinolones, such as ciprofloxacin. Tetracyclines, such as doxycycline, can also be used. The majority of cases of Legionnaires’ disease are caused by Legionella pneumophila, however many other species of Legionella have been identified.
Legionella longbeachae is another less commonly encountered species that has also been implicated in outbreaks. It is predominantly found in soil and potting compost, and has caused outbreaks of Pontiac fever, the non-respiratory and less severe variant of Legionnaires’ disease. -
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 167
Incorrect
-
EMLA cream is a topical local anaesthetic containing which of the following:
Your Answer:
Correct Answer: 50/50 mixture 2.5% lidocaine and 2.5% prilocaine
Explanation:EMLA cream, an effective topical local anaesthetic, is a 50/50 mixture of 2.5% prilocaine and 2.5% lidocaine.
-
This question is part of the following fields:
- Anaesthesia
- Pharmacology
-
-
Question 168
Incorrect
-
Which of the following statements is correct with regards to Horner's syndrome?
Your Answer:
Correct Answer: Miosis occurs due to paralysis of the dilator pupillae muscle.
Explanation:The characteristics of Horner’s syndrome are pupil constriction, partial ptosis and anhidrosis.
-
This question is part of the following fields:
- Anatomy
- Head And Neck
-
-
Question 169
Incorrect
-
Regarding benzylpenicillin, which of the following statements is CORRECT:
Your Answer:
Correct Answer: If meningococcal disease is suspected, benzylpenicillin should be given before transfer to hospital.
Explanation:Benzylpenicillin (although inactivated by bacterial beta-lactamases) is effective for many streptococcal (including pneumococcal), gonococcal, and meningococcal infections and also for anthrax, diphtheria, gas gangrene, leptospirosis, and treatment of Lyme disease. If meningococcal disease (meningitis with non-blanching rash or meningococcal septicaemia) is suspected, benzylpenicillin should be given before transfer to hospital, so long as this does not delay the transfer; benzylpenicillin is no longer the drug of first choice for pneumococcal meningitis. Although benzylpenicillin is effective in the treatment of tetanus, metronidazole is preferred. Benzylpenicillin is inactivated by gastric acid and absorption from the gastrointestinal tract is poor and therefore it must be given by injection.
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 170
Incorrect
-
Which of the following does NOT increase free ionised calcium levels:
Your Answer:
Correct 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
-
-
Question 171
Incorrect
-
Which of the following does NOT typically cause a neutrophil leucocytosis:
Your Answer:
Correct Answer: Glandular fever
Explanation:Causes of neutrophil leucocytosis:
Bacterial infection
Inflammation and tissue necrosis (e.g. cardiac infarct, trauma, vasculitis, myositis)
Metabolic disorders (e.g. uraemia, acidosis, eclampsia, gout)
Pregnancy
Acute haemorrhage or haemolysis
Neoplasms of all types
Drugs (e.g. corticosteroid therapy, lithium, tetracyclines)
Asplenia
Myeloproliferative disorders (e.g. CML, essential thrombocythaemia, polycythaemia vera, myelofibrosis)
Rare inherited disorders -
This question is part of the following fields:
- Immune Responses
- Pathology
-
-
Question 172
Incorrect
-
On his stool culture, a patient with a diarrhoeal illness grows Escherichia coli.
What SINGLE statement about Escherichia coli is true?
Your Answer:
Correct 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
-
-
Question 173
Incorrect
-
One of these statements about cohort studies is true:
Your Answer:
Correct Answer: They are longitudinal in nature
Explanation:A cohort study is a longitudinal, observational study. It follows a group of patients (the cohort) forward in time and monitors the effects of the aetiological factor under study upon them.
Cohort studies are usually of longer duration and are more expensive than case-control studies. They, however, provide more useful and reliable information.
Cohort studies follow a cohort of patients who don’t have a disease and evaluate the absolute and relative risk of contracting the disease after exposure to the aetiological agent.
Cross-sectional studies are the best way to determine the prevalence of a disease. while Cohort studies are better at determining the incidence of a disease.
-
This question is part of the following fields:
- Evidence Based Medicine
-
-
Question 174
Incorrect
-
An 82 year old man has fever, left sided abdominal and back pain and presents to the emergency room. Imaging reveals a large perinephric abscess. Which of the following most likely describes the fluid location:
Your Answer:
Correct Answer: Between the renal capsule and the renal fascia
Explanation:The perinephric fat is immediately external to the renal capsule and completely surrounds the kidney. The renal fascia surrounds the perinephric fat and the paranephric fat is external to the renal fascia. The location of a perinephric abscess is in the perinephric fat between the renal capsule and the renal fascia.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 175
Incorrect
-
A 15-year-old girl took 20 tablets of paracetamol almost 4 hours ago after her mother for refused to provide her permission for her to go on a girl's trip. The girl is healthy and has no known comorbidities or drug history. Which one of the following is TRUE regarding paracetamol?
Your Answer:
Correct Answer: It is excreted renally
Explanation:Acetaminophen is an acetanilide derivative and is a widely used non-prescription analgesic and antipyretic medication for mild-to-moderate pain and fever.
The route of elimination: Paracetamol is metabolised extensively in the liver and excreted in the urine mainly as inactive glucuronide and sulfate conjugates, <5% is excreted as free (unconjugated) acetaminophen, and >90% of the dose administered is excreted within 24 hours.
It is thought to work by selectively inhibiting COX-1 receptors in the brain and spinal cord: It is categorized by the FDA as an NSAID as it is believed to selectively inhibit cyclo-oxygenase 3 (COX-3) receptors in the brain and spinal cord.
COX-3 is a unique variant of the more known COX-1 and COX-2. It is responsible for the production of prostaglandins in central areas, which sensitizes free nerve endings to the chemical mediators of pain. Therefore, by selectively inhibiting COX-3, paracetamol effectively reduces pain sensation by increasing the pain threshold.
Toxicity is primarily due to glutathione production: Acetaminophen metabolism by the CYP2E1 pathway releases a toxic metabolite known as N-acetyl-p-benzoquinoneimine (NAPQI). NAPQI primarily contributes to the toxic effects of acetaminophen. NAPQI is an intermediate metabolite that is further metabolized by fast conjugation with glutathione. The conjugated metabolite is then excreted in the urine as mercapturic acid. High doses of acetaminophen (overdoses) can lead to hepatic necrosis due to depleting glutathione and high binding levels of reactive metabolite (NAPQI) to important parts of liver cells.
Acetaminophen can be administered orally, rectally, or intravenously. It is predominantly metabolized in the liver, and the elimination half-life is 1-3 hours after a therapeutic dose. But maybe greater than 12 hours after an overdose.
It is primarily metabolized via the cytochrome p450 enzyme system: It is predominantly metabolized in the liver by three main metabolic pathways:
1. Glucuronidation (45-55%)
2. Sulphate conjugation (30-35%)
3. N-hydroxylation via the hepatic cytochrome p450 enzyme system (10-15%) -
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
-
-
Question 176
Incorrect
-
How does an action potential in the motor end plate rapidly spread to the central portions of the muscle cells?
Your Answer:
Correct Answer: Transverse tubules
Explanation:When the concentration of intracellular Ca2+rises, muscle contraction occurs. The pathway of an action potential is down tube-shaped invaginations of the sarcolemma called T-tubules (transverse tubules). These penetrate throughout the muscle fibre and lie adjacent to the terminal cisternae of the sarcoplasmic reticulum. The voltage changes in the T-tubules result in the opening of sarcoplasmic reticulum Ca2+channels and there is there is release of stored Ca2+into the sarcoplasm. Thus muscle contraction occurs via excitation-contraction coupling (ECC) mechanism.
-
This question is part of the following fields:
- Basic Cellular
- Physiology
-
-
Question 177
Incorrect
-
A 23 year old woman has noticed her skin seems to have a yellow tinge and presents to the emergency room. On examination she is found to have jaundice and mild splenomegaly, and blood tests show that her Hb is 79 g/L. She only takes one regular medication. The medication that is most likely to cause haemolytic anaemia is:
Your Answer:
Correct Answer: Mefenamic acid
Explanation:Mefenamic acid is a nonsteroidal anti-inflammatory drug (NSAID) that is used short-term (7 days or less) to treat mild to moderate pain in adults and children who are at least 14 years old. Mefenamic acid is also used to treat menstrual pain. It has only minor anti-inflammatory properties and has occasionally been associated with diarrhoea and haemolytic anaemia. If these occur, treatment should be discontinued.
-
This question is part of the following fields:
- Musculoskeletal
- Pharmacology
-
-
Question 178
Incorrect
-
The sensory innervation of the oropharynx is provided by which of the following nerves:
Your Answer:
Correct Answer: Glossopharyngeal nerve
Explanation:Each subdivision of the pharynx has a different sensory innervation:the nasopharynx is innervated by the maxillary nervethe oropharynx is innervated by the glossopharyngeal nervethe laryngopharynx is innervated by the vagus nerve.
-
This question is part of the following fields:
- Anatomy
- Head And Neck
-
-
Question 179
Incorrect
-
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:
Correct 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 reducedC5 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 weakenedC6 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 weakenedC7 INJURY
Nerves control elbow extension and some finger extension; most can straighten their arm and have normal movement of their shouldersC8 INJURY
Nerves control some hand movement; should be able to grasp and release objectsC5 – 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 fingerC5 – 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
-
-
Question 180
Incorrect
-
A 30-year-old male farmer presents to the Emergency Department due to a wound on his right forearm sustained two days ago while working on the farm. He cleaned the wound under a tap, but there was still some dirt and debris on examination.
Past medical history reveals that he never received a tetanus vaccine.
After cleaning the wound and prescribing antibiotics, which ONE of the following actions should be taken to manage his tetanus risk?Your Answer:
Correct Answer: Tetanus vaccination and 500 IU tetanus immunoglobulin
Explanation:If a patient presents with one of the following types of wounds, they are at risk of contracting tetanus and should be vaccinated immediately:
1) Contaminated puncture-type wounds from gardening and farming (as they may contain tetanus spores)
2) Wounds containing foreign bodies
3) Open (compound) fractures
4) Wounds or burns with sepsis
5) Animal bites and scratches (animal saliva does not contain tetanus spores unless the animal was routing in soil or lives in an agriculture setting)Extremely high-risk tetanus-prone wounds are any of the above wounds with one of the following:
1) Any wound contaminated by materials containing tetanus spores, e.g., soil, manure
2) Burns or wounds with extensive devitalised tissue
3) Wounds or burns with surgical intervention delayed for more than six hours even if the initial injury was not heavily contaminatedThe CDC recommends that adults who have never been vaccinated for tetanus receive a quick shot of the tetanus vaccine along with a booster dose ten years later. A tetanus-prone wound in an unvaccinated individual should also receive a high dose of tetanus immunoglobulin. The injected antibodies will prevent tetanus infection as the patient does not have any pre-existing antibodies against the disease.
In this case, the patient has a high risk, contaminated wound. He should receive a high dose of tetanus immunoglobulin along with the tetanus vaccine. (The preventative dose of tetanus immunoglobulin is 250 IU in most cases unless over 24 hours have passed since the injury or the wound is heavily contaminated, then 500 IU should be given.) His physician also needs to be contacted to arrange the remainder of the course as indicated in this case.
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 181
Incorrect
-
Which of the following is NOT a typical clinical feature of beta-thalassaemia major:
Your Answer:
Correct Answer: Increased bleeding tendency
Explanation:Features include:
– severe anaemia (becoming apparent at 3 – 6 months when the switch from gamma-chain to beta-chain production takes place)
– failure to thrive
– hepatosplenomegaly (due to excessive red cell destruction, extramedullary haemopoiesis and later due to transfusion related iron overload)
– expansion of bones (due to marrow hyperplasia, resulting in bossing of the skull and cortical thinning with tendency to fracture)
– increased susceptibility to infections (due to anaemia, iron overload, transfusion and splenectomy)
– osteoporosis
– hyperbilirubinaemia and gallstones
– hyperuricaemia and gout
– other features of haemolytic anaemia
– liver damage and other features of iron overload -
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 182
Incorrect
-
What is the effect of a positive inotrope on the Starling curve:
Your Answer:
Correct Answer: Shifts the curve upwards
Explanation:Contractility (inotropy) is the intrinsic ability of cardiac muscle to develop force at a given muscle length. It is determined by the intracellular [Ca2+] and can be estimated by the ejection fraction. Increases in contractility cause an increase in stroke volume/cardiac output for any level of right atrial pressure or end-diastolic volume, and hence shift the Starling curve upwards. Decreases in contractility cause a decrease in stroke volume/cardiac output for any level of right atrial pressure or end-diastolic volume and hence shift the Starling curve downwards.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 183
Incorrect
-
In which of the following would you NOT typically see a neutropaenia:
Your Answer:
Correct Answer: Asplenism
Explanation:Causes of neutropaenia:
Drug-induced (e.g. chemotherapy, chloramphenicol, co-trimoxazole, phenytoin, carbamazepine, carbimazole, furosemide, chloroquine, clozapine, some DMARDs)
Benign (racial or familial)
Cyclical
Immune (e.g. SLE, Felty’s syndrome, hypersensitivity and anaphylaxis)
Leukaemia
Infections (e.g. HIV, hepatitis, fulminant bacterial infection)
General Pancytopaenia
Hypersplenism, aplastic anaemia, malignant infiltration of bone marrow, megaloblastic anaemia, chemotherapy, myelodysplasia -
This question is part of the following fields:
- Immune Responses
- Pathology
-
-
Question 184
Incorrect
-
Atracurium is used as a muscle relaxant during endotracheal intubation. This drug’s mechanism of action is best described by which of the following?
Your Answer:
Correct Answer: Nicotinic acetylcholine receptor antagonist
Explanation:Atracurium is a non-depolarizing neuromuscular blocker that is used to help with intubation and controlled ventilation by causing muscle relaxation and paralysis.
At the neuromuscular junction’s post-synaptic membrane, atracurium competes with acetylcholine for nicotinic (N2) receptor binding sites. This prevents the receptors from being stimulated by acetylcholine.
Muscle paralysis occurs gradually due to the competitive blockade.
-
This question is part of the following fields:
- Anaesthesia
- Pharmacology
-
-
Question 185
Incorrect
-
Regarding the abductor pollicis longus, which of the following statements is true?
Your Answer:
Correct Answer: It extends the thumb at the carpometacarpal joint
Explanation:Abductor pollicis longus is a muscle found in the posterior compartment of the forearm. It is one of the five deep extensors in the forearm, along with the supinator, extensor pollicis brevis, extensor pollicis longus and extensor indicis.
Abductor pollicis longus is innervated by the posterior interosseous nerve (C7, C8), which is a continuation of the deep branch of the radial nerve. The radial nerve is a branch of the posterior cord of the brachial plexus.
Blood supply to the abductor pollicis longus muscle comes from the interosseous branches of the ulnar artery.
Acting alone or with abductor pollicis brevis, abductor pollicis longus pulls the thumb away from the palm. More specifically, it produces (mid-) extension and abduction of the thumb at the first metacarpophalangeal joint. This action is seen in activities such as bowling and shovelling.
Working together with the long and short extensors of the thumb, the muscle also helps to fully extend the thumb at the metacarpophalangeal joint. This action is important for loosening the hand grip, for example, when letting go of objects previously being held. Abductor pollicis longus also helps to abduct the hand (radial deviation) at the radiocarpal joint.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 186
Incorrect
-
A 39-year-old man with a long history of depression presents after intentionally overdoing his heart medication. Verapamil immediate-release 240 mg is the tablet he takes for this condition, he says. He took the pills about 30 minutes ago, but his wife discovered him right away and rushed him to the emergency room.
Which of the following is a verapamil toxicity?Your Answer:
Correct Answer: Negative inotropy
Explanation:Overdosing on calcium-channel blockers should always be taken seriously and regarded as potentially fatal. Verapamil and diltiazem are the two most lethal calcium-channel blockers in overdose. These work by binding the alpha-1 subunit of L-type calcium channels, preventing calcium from entering the cell. In cardiac myocytes, vascular smooth muscle cells, and islet beta-cells, these channels play an important role.
The following summarises the toxicity of calcium-channel blockers:
Cardiac effects
Vascular smooth muscle tone affects
Metabolic effects
Excessive negative inotropy: myocardial depression
Negative chronotropy: sinus bradycardia
Negative dromotropy: atrioventricular node blockade
Decreased afterload
Systemic hypotension
Coronary vasodilation
Hypoinsulinaemia
Calcium channel blocker-induced insulin resistance -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 187
Incorrect
-
Which of the following is NOT a typical feature of an abducens nerve palsy:
Your Answer:
Correct Answer: Inability to look up
Explanation:CN VI palsies result in a convergent squint at rest (eye turned inwards) with inability to abduct the eye because of unopposed action of the rectus medialis. The patient complains of horizontal diplopia when looking towards the affected side. With complete paralysis, the eye cannot abduct past the midline.
-
This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
-
-
Question 188
Incorrect
-
In the Kaplan-Meier plot, which of the following labels should be applied to the X-axis?
Your Answer:
Correct Answer: Time in years
Explanation:Kaplan-Meier estimate is one of the best options to be used to measure the fraction of subjects living for a certain amount of time after treatment. In clinical trials or community trials, the effect of an intervention is assessed by measuring the number of subjects survived or saved after that intervention over a period of time. The time starting from a defined point to the occurrence of a given event, for example death, is called as survival time and the analysis of group data as survival analysis.
The graph plotted between estimated survival probabilities/estimated survival percentages (on Y axis) and time past after entry into the study (on X axis) consists of horizontal and vertical lines.
-
This question is part of the following fields:
- Evidence Based Medicine
-
-
Question 189
Incorrect
-
Regarding the renin-angiotensin-aldosterone system (RAAS), which of the following statements is CORRECT:
Your Answer:
Correct Answer: Angiotensin II has a predominant vasoconstrictor effect on the efferent arteriole.
Explanation:Angiotensin II constricts both the afferent and efferent arterioles, but preferentially increases efferent resistance. The net effect of the more prominent increase in efferent tone is that the intraglomerular pressure is stable or increased, thereby tending to maintain or even raise the GFR. Renin is produced by granular cells of the juxtaglomerular apparatus. Renin cleaves plasma angiotensinogen (produced in the liver) into angiotensin I. Angiotensin I is converted by angiotensin-converting enzyme (ACE) on pulmonary endothelial cells to angiotensin II. Angiotensin II acts to potentiate sympathetic activity (positive feedback).
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 190
Incorrect
-
You review a patient with a history of Addison’s disease. He takes 100 mg of hydrocortisone per day to control this.
What dose of prednisolone is equivalent to this dose of hydrocortisone? Select ONE answer only.Your Answer:
Correct Answer: 25 mg
Explanation:Prednisolone is four times more potent than hydrocortisone, and therefore, a dose of 25 mg would be equivalent to 100 mg of hydrocortisone.
The following table summarises the relative potency of the main corticosteroids compared with hydrocortisone:
Corticosteroid
Potency relative to hydrocortisone
Prednisolone
4 times more potent
Triamcinolone
5 times more potent
Methylprednisolone
5 times more potent
Dexamethasone
25 times more potent -
This question is part of the following fields:
- Endocrine Pharmacology
- Pharmacology
-
-
Question 191
Incorrect
-
A 30-year-old man suffers from an open femoral shaft fracture after being involved in a road traffic accident. As a consequence of his injury, the nerve that was damaged innervates the popliteus muscle.
In which of the following nerves is the popliteus muscle innervated by?Your Answer:
Correct Answer: Tibial nerve
Explanation:The popliteus muscle is innervated by the tibial nerve (L4, 5 and S1).
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 192
Incorrect
-
A 22-year-old presents with acute severe asthma. He takes a drug prescribed by her GP but cannot recall the name and is receiving regular salbutamol nebulisers. His current potassium level is 2.8 mmol/l.
Which drug is least likely to have caused his hypokalaemia?
Your Answer:
Correct Answer: Spironolactone
Explanation:Serious hypokalaemia can occur in severe asthma and the effect can be potentiated by concomitant treatment with theophyllines like aminophylline, corticosteroids, thiazide and loop diuretics, and hypoxia. Plasma-potassium concentration should be monitored in severe asthma.
Spironolactone, a potassium-sparing diuretic, is not likely to have contributed to patients hypokalaemia.
-
This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
-
-
Question 193
Incorrect
-
All of the following are indications for beta-blockers EXCEPT for:
Your Answer:
Correct Answer: Prinzmetal's angina
Explanation:Beta-blockers are contraindicated in Prinzmetal’s angina.Beta-blockers may be indicated in:HypertensionPheochromocytoma (only with an alpha-blocker)AnginaSecondary prevention after ACSArrhythmias including atrial fibrillationHeart failureThyrotoxicosisAnxietyProphylaxis of migraineEssential tremorGlaucoma
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 194
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:
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
-
-
Question 195
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:
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
-
-
Question 196
Incorrect
-
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:
Correct 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
-
-
Question 197
Incorrect
-
An analytical study is conducted to compare the risk of stroke between Ticagrelor therapy and Warfarin therapy among patients with atrial fibrillation. The following is obtained from the study:
No. of patients who took Ticagrelor: 300
No. of patients who took Ticagrelor and suffered a stroke: 30
No. of patients who took Warfarin: 500
No. of patients who took Warfarin and suffered a stroke: 20
Compute for the absolute risk in the Ticagrelor group.Your Answer:
Correct Answer: 0.1
Explanation:The absolute risk (AR) is the probability or chance of an event. It is computed as the number of events in treated or control groups, divided by the number of people in that group.
AR = 30/300 = 0.1
-
This question is part of the following fields:
- Evidence Based Medicine
-
-
Question 198
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:
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
-
-
Question 199
Incorrect
-
A 30-year-old woman presents with a history of fever and sore throat. On examination, there is tonsillar exudate and cervical lymphadenopathy and a diagnosis of tonsillitis is made. A course of penicillin is prescribed.
What is the mechanism of action of penicillin?
Your Answer:
Correct Answer: Inhibition of cell wall synthesis
Explanation:Penicillin is bactericidal and produces its antimicrobial action by preventing cross-linkage between the linear peptidoglycan polymer chains that make up the bacterial cell wall. This action inhibits cell wall synthesis.
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 200
Incorrect
-
A 30 year old man stabbed in the upper arm presents to the Emergency Department and you perform a vascular examination.
The brachial pulse can be best palpated at ?Your Answer:
Correct Answer: In the antecubital fossa, medial to the tendon of the biceps brachii
Explanation:The brachial artery can be palpated in the antecubital fossa, medial to the tendon of the biceps brachii muscle.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
SESSION STATS - PERFORMANCE PER SPECIALTY
