-
Question 1
Incorrect
-
Which of the following blood groups is the least common in the UK:
Your Answer: O
Correct Answer: AB
Explanation:Blood group O is the most common in the UK (46 %), followed by group A (42 %), group B (9 %) and finally group AB (3 %).Blood group O has no antigens, but both anti-A and anti-B antibodies and thus is the universal donor. Blood group AB has both A and B antigens but no antibodies and thus is the universal recipient.Blood group A has A antigens and anti-B antibodies and blood group B has B antigens and anti-A antibodies.
-
This question is part of the following fields:
- Immune Responses
- Pathology
-
-
Question 2
Correct
-
A young boy is carried by his friends to the Emergency Department in an unconscious state. He is quickly moved into the resuscitation room. He was at a party with friends and has injected heroin. On examination, his GCS is 6/15, and he has bilateral pinpoint pupils and a very low respiratory rate of 6 breaths per minute. Which of the following is the first-line treatment for this patient?
Your Answer: Naloxone 0.8 mg IV
Explanation:Heroin is injected into the veins and is the most commonly abused drug. Acute intoxication with opioid overuse is the most common cause of death by drug overdose. The clinical features of opioid overdose are:1. Decreased respiratory rate2. Reduced conscious level or coma3. Decreased bowel sounds4. Miotic (constricted) pupils5. Cyanosis6. Hypotension7. Seizures8. Non-cardiogenic pulmonary oedema (with IV heroin usage)The main cause of death secondary to opioid overdose is respiratory depression, which usually occurs within 1 hour of the overdose. Vomiting is also common, and aspiration can occur.Naloxone is a short-acting, specific antagonist of mu(μ)-opioid receptors. It is used to reverse the effects of opioid toxicity. It can be given by a continuous infusion if repeated doses are required and the infusion rate is adjusted according to the vital signs. Initially, the infusion rate can be set at 60% of the initial resuscitative IV dose per hour.Naloxone has a shorter duration of action (6-24 hours) than most opioids, and so close monitoring according to the respiratory rate and depth of coma with repeated injections is necessary. When repeated doses are needed in opioid addicts, naloxone administration may precipitate a withdrawal syndrome with abdominal cramps, nausea and diarrhoea, but these usually settle within 2 hours.An initial dose of 0.4 to 2 mg can be given intravenously and can be repeated at 2 to 3-minute intervals to a maximum of 10mg. If the intravenous route is inaccessible, naloxone can be administered via an IO line, subcutaneously (SQ), IM, or via the intranasal (IN) route.
-
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
-
-
Question 3
Correct
-
Due to a traffic accident, a male patient was unable to flex his arm at the glenohumeral joint. Based on the patient’s current condition, which nerve is most likely damaged?
Your Answer: Axillary and suprascapular nerve
Explanation:A suprascapular nerve injury causes numbness in the shoulder, as well as weakness in abduction and external rotation. Damage to the axillary nerve can result in shoulder or arm muscle weakness, as well as difficulty lifting the arm. This is because the deltoid and supraspinatus muscles, which are innervated by the axillary and suprascapular nerves, are responsible for abduction of the arm at the shoulder joint.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 4
Correct
-
Which of the following types of food is most commonly implicated in anaphylactic reactions:
Your Answer: Nuts
Explanation:Anaphylaxis can be triggered by any of a very broad range of triggers, but those most commonly identified include food, drugs, latex and venom. Of foods, nuts are the most common cause; muscle relaxants, antibiotics, NSAIDs and aspirin are the most commonly implicated drugs. Food is the commonest trigger in children and drugs the commonest in adults. A significant number of cases are idiopathic. Most reactions occur over several minutes; rarely, reactions may be slower in onset. The speed of onset of the reaction depends on the trigger e.g. intravenous medications will cause a more rapid onset than stings which in turn will cause a more rapid onset than ingestion of food.
-
This question is part of the following fields:
- Pharmacology
- Respiratory
-
-
Question 5
Correct
-
You've been asked to give a discussion to a group of medical students about skeletal muscle physiology and its use in clinical medicine. They pose a series of difficult questions to you.Which of the following definitions for the A-band of the sarcomere is correct?
Your Answer: A band that contains the entire length of a single thick filament (myosin)
Explanation:Myofibrils, which are around 1 m in diameter, make up each myofiber. The cytoplasm separates them and arranges them in a parallel pattern along the cell’s long axis. These myofibrils are made up of actin and myosin filaments that are repeated in sarcomeres, which are the myofiber’s basic functional units.Myofilaments are the filaments that make up myofibrils, and they’re made mostly of proteins. Myofilaments are divided into three categories:Myosin filaments are thick filaments made up mostly of the protein myosin.Actin filaments are thin filaments made up mostly of the protein actin.Elastic filaments are mostly made up of the protein titin.The sarcomere is a Z-line segment that connects two adjacent Z-lines.The I-bands are thin filament zones that run from either side of the Z-lines to the thick filament’s beginning.Between the I-bands is the A-band, which spans the length of a single thick filament.The H-zone is a zone of thick filaments that is not overlaid by thin filaments in the sarcomere’s centre. The H-zone keeps the myosin filaments in place by surrounding them with six actin filaments each.The M-band (or M-line) is a disc of cross-connecting cytoskeleton elements in the centre of the H-zone.The thick filament is primarily made up of myosin. The thin filament is primarily made up of actin. Actin, tropomyosin, and troponin are found in a 7:1:1 ratio in thin filaments.
-
This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
-
-
Question 6
Incorrect
-
The cutaneous circulation is responsible for the skin's blood supply. Because the skin is not a highly metabolically active tissue with low energy requirements, its blood supply differs from that of other tissues. Instead of capillaries, some of the circulating blood volume in the skin passes through arteriovenous anastomoses (AVAs).Which of the following statements regarding arteriovenous anastomoses is correct?
Your Answer: AVAs act like capillaries in allowing the transport of solutes across their walls
Correct Answer: AVAs are innervated by sympathetic fibres originating from the hypothalamus
Explanation:Short vessels called arteriovenous anastomoses (AVAs) link tiny arteries and veins. They have a large lumen diameter. The strong and muscular walls allow AVAs to completely clog the vascular lumen, preventing blood flow from artery to vein (acting like a sphincter). When the AVAs open, they create a low-resistance connection between arteries and veins, allowing blood to flow into the limbs’ superficial venous plexuses. There is no diffusion of solutes or fluid into the interstitium due to their strong muscle walls.AVAs are densely innervated by adrenergic fibres from the hypothalamic temperature-regulation centre. High sympathetic output occurs at normal core temperatures, inducing vasoconstriction of the AVAs and blood flow through the capillary networks and deep plexuses. When the temperature rises, sympathetic output decreases, producing AVA vasodilation and blood shunting from the artery to the superficial venous plexus. Heat is lost to the environment as hot blood rushes near to the skin’s surface.AVAs are a specialized anatomical adaptation that can only be found in large quantities in the fingers, palms, soles, lips, and pinna of the ear.
-
This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
-
-
Question 7
Correct
-
A 52-year-old female visits the Emergency Department complaining of an acute worsening of her asthma symptoms. A detailed history reveals that she took one of her brother's heart pills without a prescription as she was experiencing palpitations and thought it would cure her. Her shortness of breath was suddenly exacerbated after ingesting this medicine. Which one of the following medications has this woman most likely consumed?
Your Answer: Propranolol
Explanation:Propranolol, like other non-selective beta-blockers, is contraindicated in patients with asthma. These drugs can cause acute bronchospasm, therefore worsening symptoms, especially in high doses. However, there has been some recent evidence that long-term use of selective beta-blockers in mild or moderate asthma patients can be safe.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 8
Incorrect
-
Which of the following nerves supplies the abductor pollicis brevis?
Your Answer: The palmar digital branch of the median nerve
Correct Answer: The recurrent branch of the median nerve
Explanation:Abductor pollicis brevis is innervated by the recurrent (thenar) branch of median nerve (root value C8 and T1).
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 9
Incorrect
-
Stimulation of J receptors located on alveolar and bronchial walls results in all of the following EXCEPT for:
Your Answer: Hypotension
Correct Answer: Tachycardia
Explanation:Juxtapulmonary or ‘J’ receptors are located on alveolar and bronchial walls close to the capillaries. Their afferents are small unmyelinated C-fibres or myelinated nerves in the vagus nerve. Activation causes depression of somatic and visceral activity by producing apnoea or rapid shallow breathing, a fall in heart rate and blood pressure, laryngeal constriction and relaxation of skeletal muscles via spinal neurones. J receptors are stimulated by increased alveolar wall fluid, pulmonary congestion and oedema, microembolism and inflammatory mediators. J receptors are thought to be involved in the sensation of dyspnoea in lung disease.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 10
Correct
-
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: 500No. of post-menopausal women who took Calcium and suffered a hip fracture: 10No. of post-menopausal women who took placebo: 500No. of post-menopausal women who took placebo and suffered a hip fracture: 25Compute for the absolute risk in the placebo group.
Your Answer: 0.05
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 = 25/500 = 0.05
-
This question is part of the following fields:
- Evidence Based Medicine
-
SESSION STATS - PERFORMANCE PER SPECIALTY
