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Question 1
Correct
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Which of the following is NOT a benefit of low molecular weight heparin (LMWH) over unfractionated heparin therapy:
Your Answer: Its effects can be rapidly and completely reversed with protamine sulfate.
Explanation:Advantages of LMWHGreater ability to inhibit factor Xa directly, interacting less with platelets and so may have a lesser tendency to cause bleedingGreater bioavailability and longer half-life in plasma making once daily subcutaneous administration possibleMore predictable dose response avoiding the need for routine anticoagulant monitoringLower associated risk of heparin-induced thrombocytopenia or of osteoporosis
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 2
Correct
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The action potential is generated by excitable tissues, which are specialized tissues that can generate a meaningful electrical signal. Local currents transport action potentials down the axons of neurons.Which of the following claims about the action potential's conduction is correct?Â
Your Answer: The areas of the membrane that have recently depolarised will not depolarise again due to the refractory period
Explanation:Local currents propagate action potentials down the axons of neurons. Following depolarization, this local current flow depolarizes the next axonal membrane, and when this region crosses the threshold, more action potentials are formed, and so on. Due to the refractory period, portions of the membrane that have recently depolarized will not depolarize again, resulting in the action potential only being able to go in one direction.The square root of axonal diameter determines the velocity of the action potential; the axons with the biggest diameter have the quickest conduction velocities. When a neuron is myelinated, the speed of the action potential rises as well.The myelin sheath is an insulating coating that surrounds certain neural axons. By increasing membrane resistance and decreasing membrane capacitance, the myelin coating increases conduction. This enables faster electrical signal transmission via a neuron, making them more energy-efficient than non-myelinated neuronal axons.Nodes of Ranvier are periodic holes in a myelinate axon when there is no myelin and the axonal membrane is exposed. There are no gated ion channels in the portion of the axon covered by the myelin sheath, but there is a high density of ion channels in the Nodes of Ranvier. Action potentials can only arise at the nodes as a result of this.Electrical impulses are quickly transmitted from one node to the next, causing depolarization of the membrane above the threshold and triggering another action potential, which is then transmitted to the next node. An action potential is rapidly conducted down a neuron in this manner. Saltatory conduction is the term for this.
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 3
Correct
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The most common complication of paracetamol overdose is:
Your Answer: Hepatic failure
Explanation:The maximum daily dose of paracetamol in an adult is 4 grams. Doses greater than this can lead to hepatotoxicity and, less frequently, acute kidney injury. Early symptoms of paracetamol toxicity include nausea, vomiting, and abdominal pain, and usually settle within 24 hours. Symptoms of liver damage include right subcostal pain and tenderness, and this peaks 3 to 4 days after paracetamol ingestion. Other signs of hepatic toxicity include encephalopathy, bleeding, hypoglycaemia, and cerebral oedema.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 4
Correct
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The myocardium is responsible for creating the force with which the atrial and ventricular muscles contract. It is made up of myocytes, which are heart muscle cells.Which of the following statements about cardiac muscle anatomy is correct?Â
Your Answer: Cardiac myocytes have intercalated discs
Explanation:Typically, granuloma has Langerhan’s cells (large multinucleated cells ) surrounded by epithelioid cell aggregates, T lymphocytes and fibroblasts.Antigen presenting monocytic cells found in the skin are known as Langerhan’s cells.
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 5
Incorrect
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A 32-year-old woman suffers a deep wound to her thigh while she was climbing over a barbed wire fence. As a consequence of her injury, the nerve that was severed innervates the gracilis muscle.In which of the following nerves is the gracilis muscle innervated by?
Your Answer: Femoral nerve
Correct Answer: Anterior branch of the obturator nerve
Explanation:The gracilis muscles is innervated by the anterior branch of the obturator nerve (L2-L4).
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 6
Correct
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Which of the following best describes the main sites of constriction of the ureters:
Your Answer: At the ureteropelvic junction, at the pelvic brim and where the ureters enter the bladder
Explanation:At three points along their course, the ureters are constricted denoting the most likely areas for renal calculi to lodge:the first point is at the ureteropelvic junction (where the renal pelvis becomes continuous with the ureter)the second point is where the ureter crosses the common iliac vessels at the pelvic brimthe third point is at the vesicoureteric junction (where the ureter enters the wall of the bladder)
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 7
Correct
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A 66-year-old male was admitted from the Emergency Department due to severe pain in the left forearm and hand, refractory to pain medication along with pallor and hypothermia of the affected limb. Ultrasound doppler showed an arterial embolism. Circulation was restored after vascular surgery, but there was extensive, irreversible muscle damage. How will the muscle heal from an injury of this type?
Your Answer: Diffuse formation of fibrous tissue
Explanation:Once muscle tissue is damaged, there will be healing via diffuse formation of fibrous tissue, especially due to the widespread ischemia. Callus formation takes place in the healing of bone, not muscle. Organised scar formation occurs when a lacerated wound is approximated by sutures so that primary intention wound healing can occur. Liquefaction degeneration occurs following ischemia in the brain. Volkmann’s ischemic contracture may occur, but it is not the primary type of healing that will take place but rather the effect of the fibrous scar formation.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 8
Incorrect
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A 29-year-old woman presents with night sweats, fever, and haemoptysis. A diagnosis of tuberculosis was suspected.Which of the following statements regarding the diagnosis of tuberculosis is considered correct?
Your Answer: Mycobacteria tuberculosis appears blue on acid-fast staining
Correct Answer: Mycobacteria tuberculosis can be typed using a RFLP method
Explanation:Although a variety of clinical specimens may be submitted to thelaboratory to recover MTB and NTM, respiratory secretions suchas sputum and bronchial aspirates are the most common. Anearly-morning specimen should be collected on three consecutivedays, although recent studies have suggested that the addition ofa third specimen does not significantly increase the sensitivityof detecting Mycobacteria.Mycobacterium tuberculosis appear red on acid-fast staining because they take up the primary stain, which is carbolfuchsin, and is not decolorized by the acid alcohol anymore.Culture on Lowenstein-Jensen medium should be read within 5 to 7 days after inoculation and once a week thereafter for up to 8 weeks.Nucleic acid amplification assays designed to detect M. tuberculosis complexbacilli directly from patient specimens can be performed in as little as 6 to 8 hours on processed specimens.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 9
Incorrect
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Which of the following muscles acts as an extensor of the shoulder joint?
Your Answer: Pectoralis major
Correct Answer: Teres major
Explanation:The glenohumeral joint possesses the capability of allowing an extreme range of motion in multiple planes.Flexion – Defined as bringing the upper limb anterior in the sagittal plane. The usual range of motion is 180 degrees. The main flexors of the shoulder are the anterior deltoid, coracobrachialis, and pectoralis major. Biceps brachii also weakly assists in this action.Extension—Defined as bringing the upper limb posterior in a sagittal plane. The normal range of motion is 45 to 60 degrees. The main extensors of the shoulder are the posterior deltoid, latissimus dorsi, and teres major.Internal rotation—Defined as rotation toward the midline along a vertical axis. The normal range of motion is 70 to 90 degrees. The internal rotation muscles are the subscapularis, pectoralis major, latissimus dorsi, teres major, and the anterior aspect of the deltoid.External rotation – Defined as rotation away from the midline along a vertical axis. The normal range of motion is 90 degrees. Primarily infraspinatus and teres minor are responsible for the motion.Adduction – Defined as bringing the upper limb towards the midline in the coronal plane. Pectoralis major, latissimus dorsi, and teres major are the muscles primarily responsible for shoulder adduction.Abduction – Defined as bringing the upper limb away from the midline in the coronal plane. The normal range of motion is 150 degrees. Due to the ability to differentiate several pathologies by the range of motion of the glenohumeral joint in this plane of motion, it is essential to understand how different muscles contribute to this action.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 10
Correct
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A patient presents to ED with heartburn for which they already take regular antacids. Which of the following drugs can be affected if taken with antacids:
Your Answer: Digoxin
Explanation:Antacids should preferably not be taken at the same time as other drugs since they may affect absorption. When antacids are taken with acidic drugs (e.g. digoxin, phenytoin, chlorpromazine, isoniazid) they cause the absorption of the acidic drugs to be decreased, which causes low blood concentrations of the drugs, which ultimately results in reduced effects of the drugs. Antacids taken with drugs such as pseudoephedrine and levodopa increase absorption of the drugs and can cause toxicity/adverse events due to increased blood levels of the drugs. Antacids that contain magnesium trisilicate and magnesium hydroxide when taken with some other medications (such as tetracycline) will bind to the drugs, and reduce their absorption and effects.
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This question is part of the following fields:
- Gastrointestinal
- Pharmacology
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Question 11
Correct
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A 29 year old patient with known inflammatory bowel disease presents to ED with surgical complications following his recent ileocaecal resection. Removal of the terminal ileum may result in the malabsorption of which of the following:
Your Answer: Vitamin B12
Explanation:On ingestion, vitamin B12 is bound to R protein found in saliva and gastric secretions, which protects it from digestion in the stomach. Intrinsic factor is secreted by gastric parietal cells. Receptors for the IF-B12 complex are present in the membrane of epithelial cells of the terminal ileum, which bind the complex and allow uptake of vitamin B12 across the apical membrane by endocytosis. Vitamin B12 is then transported across the basal membrane into the portal blood where it is bound to transcobalamin II and processed by the liver. In pernicious anaemia, there are autoantibodies against gastric parietal cells and intrinsic factor, resulting in vitamin B12 deficiency anaemia.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 12
Correct
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Polyuria and polydipsia develop in a patient with a history of affective disorders illness who has been on long-term lithium. She has a fluid deprivation test because she is suspected of having nephrogenic diabetic insipidus.Which of the following urine osmolality findings would be the most reliable in confirming the diagnosis?Â
Your Answer: After fluid deprivation <300 mosmol/kg, after IM desmopressin <300 mosmol/kg
Explanation:The inability to produce concentrated urine is a symptom of diabetes insipidus. Excessive thirst, polyuria, and polydipsia are all symptoms of this condition. There are two forms of diabetes insipidus: Nephrogenic diabetes insipidus and cranial (central) diabetes insipidus.A lack of ADH causes cranial diabetic insipidus. Patients with cranial diabetes insipidus can have a urine output of up to 10-15 litres per 24 hours, however most patients can maintain normonatraemia with proper fluid consumption. Thirty percent of cases are idiopathic, while another thirty percent are caused by head injuries. Neurosurgery, brain tumours, meningitis, granulomatous disease (e.g. sarcoidosis), and medicines like naloxone and phenytoin are among the other reasons. There is also a very rare hereditary type that is linked to diabetes, optic atrophy, nerve deafness, and bladder atonia.Renal resistance to the action of ADH causes nephrogenic diabetes insipidus. Urine output is significantly increased, as it is in cranial diabetes insipidus. Secondary polydipsia can keep serum sodium levels stable or raise them. Chronic renal dysfunction, metabolic diseases (e.g., hypercalcaemia and hypokalaemia), and medications, such as long-term lithium use and demeclocycline, are all causes of nephrogenic diabetes insipidus.The best test to establish if a patient has diabetes insipidus vs another cause of polydipsia is the water deprivation test, commonly known as the fluid deprivation test. It also aids in the distinction between cranial and nephrogenic diabetes insipidus. Weight, urine volume, urine osmolality, and serum osmolality are all measured after patients are denied water for up to 8 hours. At the end of the 8-hour period, 2 micrograms of IM desmopressin is given, and measures are taken again at 16 hours.The following are the way results are interpreted:Urine osmolality after fluid deprivation : Urine osmolality after IM desmopressinCranial diabetes insipidus800 mosmol/kgNephrogenic diabetes insipidus<300 mosmol/kg : 800 mosmol/kg : >800 mosmol/kg
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 13
Correct
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A 59-year-old man presents with a goitre, increased sweating, weight loss, and palpitations. A diagnosis of hyperthyroidism is suspected.What is the most appropriate first-line investigation?
Your Answer: TSH level
Explanation:A thyroid function test is used in the diagnosis of hyperthyroidism.Serum TSH should be the first-line investigation for patients with suspected hyperthyroidism as it has the highest sensitivity and specificity for hyperthyroidism. A normal TSH level almost always excludes the diagnosis, though there are rare exceptions to this.Antithyroglobulin antibodies are commonly present in Graves’ disease, but the test has a sensitivity of 98% and specificity of 99, and is not widely available.Radioactive iodine uptake scan using iodine-123 – shows low uptake in thyroiditis but high in Graves’ disease and toxic multinodular goitre. It is however, not first-line investigation in this caseThyroid ultrasound scan – is a cost-effective and safe alternative to the radioactive iodine uptake scan.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 14
Incorrect
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Which of the following laboratory findings is NOT typical of Hodgkin lymphoma:
Your Answer: Eosinophilia
Correct Answer: Basophilia
Explanation:Features may include:Normochromic normocytic anaemia is most common; bone marrow failure involvement is unusual in early disease, but if it occurs bone marrow failure may develop with leucoerythroblastic anaemiaOne-third of patients have a neutrophilia; eosinophilia is frequentAdvanced disease is associated with lymphopenia and loss of cell-mediated immunityPlatelet count is normal or increased in early disease and reduced in later stagesESR and CRP are usually raised (ESR is useful in monitoring disease progress)Serum LDH is raised initially in 30-40% of casesDiagnosis is made by histological examination of an excised lymph nodeThe distinctive multinucleate polypoid RS cell is central to the diagnosis of the four classic types of HL (95% of cases)
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This question is part of the following fields:
- Haematology
- Pathology
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Question 15
Correct
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One of these statements about significance tests is true.
Your Answer: A p value of less than 1 in 20 is considered ‘statistically significant’
Explanation:The p value is statistically significant when it is less than 0.05 (5% or 1 in 20).Statistical significance is not the same as clinical significance. The null hypothesis states that there is no difference between the groups.The power of a study is the probability of correctly rejecting the null hypothesis when it is false.A type I error occurs when the null hypothesis has been rejected when it is true. A type II error occurs when the null hypothesis has been accepted when it is actually false.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 16
Correct
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A clinical audit cycle comprises of 5 steps. Each of these processes are listed below:Which is the correct order that these should occur?1. Observation of practice and collection of data2. Identification of the problem3. Implementation of change4. Definition of criteria and setting of standards5. Analysis of data and comparison of performance with the criteria and standards
Your Answer: 2,4,1,5,3
Explanation:An audit assesses if a certain aspect of health care is attaining a recognized standard. This lets care providers and patients know where their service is doing well, and where there could be improvements. The aim is to achieve quality improvement and improve outcomes for patients.Audits are a quality improvement measure and one of the 7 pillars of clinical governance. It allows organizations to continually work toward improving quality of care by showing them where they are falling short, allows them to implement improvements, and reaudit or close the audit cycle to see if beneficial change has taken place.Clinical audits are a cycle with several steps:1. Identification of the problem2. Definition of criteria and setting of standards3. Observation of practice and collection of data4. Analysis of data and comparison of performance with the criteria and standards5. Implementation of change
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This question is part of the following fields:
- Evidence Based Medicine
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Question 17
Incorrect
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For an action potential to occur, which of the following must be true:
Your Answer: All of the above
Correct Answer: Depolarisation of the membrane must reach threshold potential
Explanation:For an action potential to occur, the membrane must become more permeable to Na+and the Na+influx must be greater than the K+efflux. An action potential occurs when depolarisation of the membrane reaches threshold potential. The membrane must be out of the absolute refractory period, however an action potential can still occur in a relative refractory period but only in response to a larger than normal stimulus.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 18
Correct
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A 38-year-old man returns from an overseas business trip with a fever and a headache. Following investigations a diagnosis of Plasmodium falciparum malaria is made.Which of the following statements regarding Plasmodium falciparum malaria is true? Select ONE answer only.
Your Answer: There may be a continuous fever
Explanation:Plasmodium falciparum malaria is transmitted by female of the Anopheles genus of mosquito. The Aedes genus is responsible for transmitting diseases such as dengue fever and yellow fever.Plasmodium falciparumis found globally but is mainly found in sub-Saharan Africa.The incubation period of Plasmodium falciparum malaria is 7-14 days.Sporozoites invade hepatocytes. Within the hepatocyte asexual reproduction occurs producing merozoites, which are released into the blood stream and invade the red blood cells of the host.Artesunate is the drug treatment of choice for Plasmodium falciparum malaria. Quinine can still be used where artesunate is not available. Often combination therapy with drugs such as doxycycline or fansidar is also required.The classic symptom of malaria is the malarial paroxysm, a cyclical occurrence of a cold phase, where the patient experiences intense chills, a hot stage, where the patient feels extremely hot and finally a sweating stage, where the fever declines and the patient sweats profusely. There may also, however, be a continuous fever.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 19
Correct
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A 44-year-old man with an acute episode of gout presents to you and you discuss treatment plan with him.Which one of these statements concerning the treatment of acute gout is true?
Your Answer: A common first-line treatment is Naproxen as a stat dose of 750 mg followed by 250 mg TDS
Explanation:High-dose NSAIDs are the first-line treatment for acute gout. In the absence of any contraindications, Naproxen 750 mg as a stat dose followed by 250 mg TDS is commonly used.Aspirin is contraindicated in gout. It reduces the urinary clearance of urate and also interferes with the action of uricosuric agents. Colchicine is preferred in patients with heart failure or in those who are intolerant of NSAIDs. It is as effective as NSAIDs in relieving acute attacks.Colchicine acts on the neutrophils, binding to tubulin to prevent neutrophil migration into the joint. Where Allopurinol is not tolerated, it has a role in prophylactic treatment of gout.Allopurinol should not be started in the acute phase of gout as it increases the severity and duration of symptoms. It is used as a prophylaxis in preventing future attacks and acts by reducing serum uric acid levels.
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This question is part of the following fields:
- Musculoskeletal Pharmacology
- Pharmacology
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Question 20
Incorrect
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A 35-year-old lady has suffered a serious brain injury. Her uvula has deviated to the right, according to inspection. Which of the following nerves is likely to be affected?
Your Answer: Right vagus nerve
Correct Answer: Left vagus nerve
Explanation:When the vagus nerve is damaged, the soft palate is paralyzed and the uvula is shifted away from the affected side. The vagus nerve innervates the uvulae muscle, which forms the uvula’s core. If only one side is innervated, contraction of the active muscle will draw the uvula towards it.
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This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
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Question 21
Incorrect
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An infection causes an Addisonian crisis in a male patient with a known history of Addison's disease.Which of the following is NOT a well-known symptom of an Addisonian crisis?
Your Answer: Fever
Correct Answer: Hyperglycaemia
Explanation:Although Addisonian crisis is a rare illness, it can be fatal if it is misdiagnosed. Hypoglycaemia and shock are the most common symptoms of an Addisonian crisis (tachycardia, peripheral vasoconstriction, hypotension, altered conscious level, and coma).Other clinical characteristics that may be present are:FeverPsychosisLeg and abdominal painDehydration and vomitingConvulsionsÂ
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 22
Correct
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A man presents to the emergency department with a hand laceration that has damaged the opponens digiti minimi muscle.All of the following statements regarding the opponens digiti minimi muscle is considered correct, except:
Your Answer: It is innervated by the superficial branch of the ulnar nerve
Explanation:Opponens digiti minimi (ODM) is an intrinsic muscle of the hand. It’s a triangular muscle that extends between the hamate bone (carpal bone) and the 5th metacarpal bone. It forms the hypothenar muscle group together with the abductor digiti minimi and flexor digiti minimi brevis, based on the medial side of the palm (hypothenar eminence). These muscles act together in moving the little finger. The opponens digiti minimi is responsible for flexion, lateral rotation and opposition of the little finger.Its origin is the hook of hamate and flexor retinaculum. It inserts into the medial border of 5th metacarpal bone. It is innervated by the deep branch of the ulnar nerve, which stems from the brachial plexus (C8, T1 spinal nerves).Its blood supply is by the deep palmar branch of ulnar artery and deep palmar arch, which is the terminal branch of the radial artery.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 23
Correct
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Which of the following statements is correct regarding flow through the cardiovascular system?
Your Answer: Turbulent blood flow may be caused by increased cardiac output.
Explanation:Frictional forces at the sides of a vessel cause a drag force on the fluid touching them in laminar blood flow, which creates a velocity gradient where the flow is greatest at the centre. Laminar blood flow may become disrupted and flow may become turbulent at high velocities, especially in large arteries or where the velocity increases sharply at points of sudden narrowing in the vessels, or across valves. There is increased tendency for thrombi formation when there is turbulent blood flow. Clinically, turbulence may be heard as a murmur or a bruit. As a result of elevated cardiac output, there may be turbulent blood flow, even when the cardiac valves are anatomically normal, and as a result, a physiological murmur can be heard. One such example is pregnancy.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 24
Incorrect
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Which of the following is where the rectovesical fascia is located:
Your Answer: Between the rectum and the posterior fornix and cervix
Correct Answer: Between the fundus of the bladder and the ampulla of the rectum
Explanation:In a triangular area between the vasa deferentia, the bladder and rectum are separated only by rectovesical fascia, commonly known as Denonvillier’s fascia.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 25
Incorrect
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A patient who shows symptoms of infection and is admitted under supervision of the medical team. The organism which caused this, is a Gram-negative bacterium, according to the culture. A penicillin therapy is suggested by the microbiologist.Which of the penicillins listed below is the most effective against Gram-negative bacteria?Â
Your Answer: Flucloxacillin
Correct Answer: Amoxicillin
Explanation:Amoxicillin and Ampicillin are more hydrophilic (broad-spectrum)Â penicillins than benzylpenicillin and phenoxymethylpenicillin. Because they may penetrate through gaps in the outer phospholipid membrane, they are effective against Gram-negative bacteria. Amoxicillin and Ampicillin are resistant to penicillinase-producing microbes.Community-acquired pneumonia, otitis media, sinusitis, oral infections, and urinary tract infections are among the most prevalent conditions for which they are prescribed. The normal adult oral dose of Amoxicillin is 500 mg three times/day, which can be increased to 1 g three times/day if necessary. Ampicillin is given to adults in doses of 0.5-1 g every 6 hours.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 26
Correct
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For a tachyarrhythmia caused by hypovolaemic shock, which of the following is the first-line treatment:
Your Answer: Synchronised DC shock
Explanation:If there are any adverse symptoms, immediate cardioversion with synchronized DC shock is recommended. If cardioversion fails to stop the arrhythmia and the symptoms persist, amiodarone 300 mg IV over 10–20 minutes should be administered before attempting another cardioversion. The loading dosage of amiodarone is followed by a 24-hour infusion of 900 mg administered into a large vein.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 27
Incorrect
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What is the interquartile range for these numbers: 11, 4, 6, 8, 3, 10, 8, 10, 4, 12, 31?
Your Answer: 5
Correct Answer: 7
Explanation:We obtain 3, 4, 4, 6, 8, 8, 10, 11, 12, and 31, and sample size (n) = 11 when we order the data. [(n+1)/2] = median 6th value = (11+1)/2 = [(n+1)/4] represents the bottom (first) quartile. (3rd value = 4th value = (11 + 1)/4 3[(n+1)/4] for the top (third) quartile 3[(11 + 1)/4] = 9th value = 11th value = 11th value = 11th value = 11th value = 11th value = 11th value = 11th value = 11th The difference between the upper and lower quartiles is the interquartile range, which is equal to 11 minus 4 = 7.
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 28
Correct
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A 24-year-old patient is suspected to have a possible acute hepatitis B infection and is currently under investigation.Which of the following markers is considered the earliest indicator of acute infection in acute Hepatitis B?
Your Answer: Hepatitis B surface Ag
Explanation:HBsAg is the serological hallmark of HBV infection. After an acute exposure to HBV, HBsAg appears in serum within 1 to 10 weeks. Persistence of this marker for more than 6 months implies chronic HBV infection.Anti-HBs is known as a neutralizing antibody, and confers long-term immunity. In patients with acquired immunity through vaccination, anti-HBs is the only serological marker detected in serum.HBcAg is an intracellular presence in infected hepatocyte, thus it is not identified in the serum. During acute infection, anti-HBc IgM and IgG emerges 1–2 weeks after the presence of HBsAg along with raised serum aminotransferase and symptoms. After 6 months of acute infection, anti-HBc IgM wears off. Anti-HBc IgG continues to detect in both patients with resolved HBV infection and chronic hepatitis B.Hepatitis D virus, also known as the delta hepatitis virus, is a defective ssRNA virus that requires HBV for replication. The infection can occur in one of two clinical forms, co-infection or superinfection. In a co-infection, the patient is simultaneously infected with HBV and HDV. In a superinfection, an HDV infection develops in a patient with a chronic HBV infection.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 29
Correct
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A 54-year-old man with a long history of poorly controlled hypertension complains of a headache and vision blurring today. In triage, his blood pressure is 210/192 mmHg. A CT head scan is scheduled to rule out the possibility of an intracranial haemorrhage. You make the diagnosis of hypertensive encephalopathy and rush the patient to reus to begin blood pressure-lowering treatment. He has a history of brittle asthma, for which he has been admitted to the hospital twice in the last year.Which of the following is the patient's preferred drug treatment?
Your Answer: 25% of the mean arterial pressure over the first hour
Explanation:End-organ damage (e.g. encephalopathy, intracranial haemorrhage, acute myocardial infarction or ischaemia, dissection, pulmonary oedema, nephropathy, eclampsia, papilledema, and/or angiopathic haemolytic anaemia) characterises a hypertensive emergency (also known as ‘accelerated hypertension’ or malignant hypertension’ It’s a life-threatening condition that necessitates rapid blood pressure reduction to avoid end-organ damage and a negative outcome.Hypertensive encephalopathy is a syndrome that includes headaches, seizures, visual changes, and other neurologic symptoms in people who have high blood pressure. It is reversible if treated quickly, but it can progress to coma and death if not treated properly.Any patient with suspected hypertensive encephalopathy should have an urgent CT scan to rule out an intracranial haemorrhage, as rapid blood pressure reduction could be dangerous in these circumstances.The drug of choice is labetalol, which reduces blood pressure steadily and consistently without compromising cerebral blood flow.An initial reduction of approximately 25% in mean arterial pressure (MAP) over an hour should be aimed for, followed by a further controlled MAP reduction over the next 24 hours. In patients who are unable to take beta-blockers, nicardipine can be used as a substitute.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 30
Correct
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A 40-year-old man who has a history of asthma arrives at the emergency department complaining of palpitations that have been going on for 5 days. Which of the following beta-blockers is the safest for an asthmatic patient?
Your Answer: Atenolol
Explanation:Atenolol is a beta blocker, which is a type of medication that works by preventing certain natural substances in the body, such as epinephrine, from acting on the heart and blood vessels. This effect reduces heart rate, blood pressure, and cardiac strain. Atenolol, bisoprolol fumarate, metoprolol tartrate, nebivolol, and (to a lesser extent) acebutolol have a lower action on beta2 (bronchial) receptors and are thus cardio selective but not cardiac specific. They have a lower effect on airway resistance, although they are not without this adverse effect.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 31
Correct
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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: 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 concentrationDecreases renal phosphate reabsorptionDecreases plasma phosphate concentrationIncreases renal tubular reabsorption of calciumIncreases calcium and phosphate absorption in the small intestineIncreases renal conversion of 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 32
Correct
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A 30-year-old patient has a mild exacerbation of his asthma. His steroid inhaler ran out a couple of weeks ago, and he has not replaced it.Which of these statements describes the mechanism of action of corticosteroids in asthma?
Your Answer: Reduction of bronchial inflammation
Explanation:Inhaled corticosteroids suppresses airway inflammation seen in asthma by downregulating pro-inflammatory proteins.They also appear to reverse components of asthma-induced structural changes (airway remodelling), including increased vascularity of the bronchial wall.Corticosteroids reduces the number of inflammatory cells (eosinophils, T lymphocytes, mast cells, and dendritic cells) in the airways.
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This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 33
Correct
-
Mannitol is primarily indicated for which of the following:
Your Answer: Cerebral oedema
Explanation:Mannitol is an osmotic diuretic that can be used to treat cerebral oedema and raised intraocular pressure. Mannitol is a low molecular weight compound and is, therefore, freely filtered at the glomerulus and is not reabsorbed. It, therefore, increases the osmolality of the glomerular filtrate and tubular fluid, increasing urinary volume by an osmotic effect. It also does not cross the blood-brain-barrier (BBB).
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 34
Incorrect
-
A 53-year-old male has presented to your clinic with the complaint of a rash on his right forearm. On examination, you discover small reddish-purple spots on the skin measuring less than 2-3 mm. They do not blanch on applying pressure. Which one of the following best fits the description given above?
Your Answer: Ecchymoses
Correct Answer: Petechiae
Explanation:Petechiae are small red or purple spots on the skin measuring less than 3 mm, caused by minor haemorrhages which do not blanch on applying pressure.Purpura measures between 3mm and 1 cm in diameter, while ecchymoses are greater than 1 cm in diameter. Both are caused due to haemorrhage. Erythema is the generalised redness of the skin. A macule is a flat, discoloured area of the skin measuring less than 1 cm in diameter.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 35
Correct
-
A 40-year-old man with episodes of blood in urine and flank pain that are recurrent presents for management. He has a history of hypertension that is difficult to control and recurrent urinary tract infections. Other findings are: bilateral masses in his flanks and haematuria (3+ on dipstick).What is the most likely diagnosis?
Your Answer: Polycystic kidney disease
Explanation:Autosomal dominant polycystic kidney disease (ADPKD) presents with abdominal or loin discomfort due to the increasing size of the kidneys, acute loin pain with or without haematuria, hypertension, and male infertility. It is the most common cause of serious renal disease and the most common inherited cause of renal failure in adults. Alport syndrome has hearing loss and eye abnormalities in addition to symptoms of kidney disease.Renal cell carcinoma presents with additional features of unexplained weight loss, loss of appetite, fever of unknown origin and anaemia.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 36
Incorrect
-
Identify the type of graph described below:This graph has been used to create visual representations to communicate the risks and benefits of treatments using 4 face categories.
Your Answer: Forest plot
Correct Answer: Cates plot
Explanation:Cates Plot, since 1999, has been used to create visual representations to communicate the risks and benefits of treatments. The essence of Cates Plot is the use of 4 face categories to visually indicate the following:People not affected by a treatment (green faces for those with a good outcome and red for those with a bad outcome)People for which treatment changes their category from a bad outcome to a good outcome (yellow faces)People for which treatment causes an adverse event and changes their category from a good outcome to a bad outcome (crossed out green faces)
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This question is part of the following fields:
- Evidence Based Medicine
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Question 37
Correct
-
During bedside rounds, an 82-year old female in the Medicine Ward complains of pain and tingling of all fingers of the right hand. The attending physician is considering carpal tunnel syndrome.Which of the following is expected to undergo atrophy in carpal tunnel syndrome?
Your Answer: The thenar eminence
Explanation:Carpal tunnel syndrome (CTS) is an entrapment neuropathy caused by compression of the median nerve as it travels through the wrist’s carpal tunnel. It is the most common nerve entrapment neuropathy, accounting for 90% of all neuropathies. Early symptoms of carpal tunnel syndrome include pain, numbness, and paraesthesia’s. These symptoms typically present, with some variability, in the thumb, index finger, middle finger, and the radial half (thumb side) of the ring finger. Pain also can radiate up the affected arm. With further progression, hand weakness, decreased fine motor coordination, clumsiness, and thenar atrophy can occur.The muscles innervated by the median nerve can be remembered using the mnemonic ‘LOAF’:L– lateral two lumbricalsO– Opponens pollicisA– Abductor pollicisF– Flexor pollicis brevisIn the early presentation of the disease, symptoms most often present at night when lying down and are relieved during the day. With further progression of the disease, symptoms will also be present during the day, especially with certain repetitive activities, such as when drawing, typing, or playing video games. In more advanced disease, symptoms can be constant.Typical occupations of patients with carpal tunnel syndrome include those who use computers for extended periods of time, those who use equipment that has vibration such as construction workers, and any other occupation requiring frequent, repetitive movement.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 38
Correct
-
A 72 year old man is brought to ED by ambulance with sudden onset chest pain, palpitations and shortness of breath. His HR is 160 bpm and BP 90/65. ECG demonstrates new-onset fast atrial fibrillation. Which of the following is the first-line treatment option in this case:
Your Answer: Synchronised DC cardioversion
Explanation:All patients with adverse features suggesting life-threatening haemodynamic instability (shock, syncope, heart failure, myocardial ischaemia) caused by new onset atrial fibrillation should undergo emergency electrical cardioversion with synchronised DC shock without delaying to achieve anticoagulation.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 39
Correct
-
Which nerve innervates the brachioradialis muscle?
Your Answer: The radial nerve
Explanation:Brachioradialis is innervated by the radial nerve (from the root values C5-C6) that stems from the posterior cord of the brachial plexus.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 40
Correct
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A patient with a history of worsening chronic breathlessness on exertion undergoes lung function testing. The results demonstrate an FEV 1 that is 58% predicted and an FEV 1 /FVC ratio less than 0.7.Which of the following is the most likely diagnosis? Select ONE answer only.
Your Answer: COPD
Explanation:Obstructive lung disorders are characterised by airway obstruction. Many obstructive diseases of the lung result from narrowing of the smaller bronchi and larger bronchioles, often because of excessive contraction of the smooth muscle itself.In obstructive lung disease, FEV1is reduced to <80% of normal and FVC is usually reduced but to a lesser extent than FEV1. The FEV1/FVC ratio is reduced to <0.7.Types of obstructive lung disorders include:Chronic obstructive pulmonary disease (COPD)AsthmaBronchiectasis
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 41
Correct
-
Which of the following could denote a diagnosis of acquired immunodeficiency syndrome (AIDS) in a patient infected with HIV:
Your 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 or 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.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 42
Incorrect
-
Which of the following is NOT a function of antibodies:
Your Answer: Neutralise toxins
Correct Answer: Act as antigen receptors on T lymphocytes
Explanation:Antibodies: Neutralise toxins and prevent attachment of pathogensTarget, opsonise or agglutinate (clump together) antigens for phagocytosisActivate the complement cascade (leading to lysis or opsonisation of the pathogen)Act as antigen receptors on B lymphocytesActivate antibody-dependent cell-mediated cytotoxicity by natural killer (NK) cells or T cytotoxic cellsProvide mucosal immunity (IgA-mediated)Stimulate degranulation of mast cells (IgE and IgG mediated)Provide passive immunity to the newborn (through transplacental passage of IgG and secretion of IgA in breast milk)
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 43
Incorrect
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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: It Gram stains red
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 favoursreplication of the bacilli and progression to disease.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 44
Correct
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Many of the chemical digestion and absorption takes place in the small intestine. Most digestive enzymes in the small intestine are secreted by the pancreas and enter the small intestine through the pancreatic duct.Which of these digestive enzymes is responsible for breaking down lipids into fatty acid and glycerol?
Your Answer: Pancreatic lipase
Explanation:The principal enzyme involved in lipid digestion is pancreatic lipase. It breaks down triglycerides into free fatty acids and monoglycerides. Pancreatic lipase works with the help of emulsifying agents secreted by the liver and the gallbladder. The main emulsifying agents are the bile acids, cholic acid and chenodeoxycholic acid. These are conjugated with the amino acids glycine and taurine to form bile salts. Bile salts are more soluble than bile acids and act as detergents to emulsify lipids. The free fatty acids and monoglycerides form tiny particles with these bile salts called micelles. The outer region of the micelle is water-attracting (hydrophilic), whereas the inner core is water-repelling (hydrophobic). This arrangement allows the micelles to enter the aqueous layers surrounding the microvilli and free fatty acids and monoglycerides to diffuse passively into the small intestinal cells.Pancreatic amylase breaks down some carbohydrates (notably starch) into oligosaccharides. Chymotrypsin is a proteolytic enzyme that aids in digestion of proteinCarboxypeptidase hydrolyses the first peptide or amide bond at the carboxyl or C-terminal end of proteins and peptides
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This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 45
Correct
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Glucagon is secreted by which of the following pancreatic cell types:
Your Answer: α cells
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:GlycogenolysisGluconeogenesisLipolysis in adipose tissueThe secretion of glucagon is also stimulated by:AdrenalineCholecystokininArginineAlanineAcetylcholineThe secretion of glucagon is inhibited by:InsulinSomatostatinIncreased free fatty acidsIncreased urea productionGlycolysis is the metabolic pathway that converts glucose into pyruvate. The free energy released by this process is used to form ATP and NADH. Glycolysis is inhibited by glucagon, and glycolysis and gluconeogenesis are reciprocally regulated so that when one cell pathway is activated, the other is inactive and vice versa.Glucagon has a minor effect of enhancing lipolysis in adipose tissue. Lipolysis is the breakdown of lipids and involves the hydrolysis of triglycerides into glycerol and free fatty acids. It makes fatty acids available for oxidation.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 46
Correct
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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: 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.
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This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 47
Incorrect
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Which of these increases osteoclast activity?
Your Answer: Calcitonin
Correct Answer: Parathyroid hormone
Explanation:Osteoclasts are bone cell that break down bone tissue. Parathyroid hormone increases osteoclastic activity.1,25-dihydroxycholecalciferol increases osteoclastic activityCalcitonin inhibits osteoclastic activityBisphosphonates are osteoclast inhibitors.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 48
Correct
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Where in the nephron is most K+reabsorbed:
Your Answer: Proximal tubule
Explanation:Approximately 65 – 70% of filtered K+is reabsorbed in the proximal tubule. Potassium reabsorption is tightly linked to that of sodium and water. The reabsorption of sodium drives that of water, which may carry some potassium with it. The potassium gradient resulting from the reabsorption of water from the tubular lumen drives the paracellular reabsorption of potassium and may be enhanced by the removal of potassium from the paracellular space via the Na+/K+ATPase pump. In the later proximal tubule, the positive potential in the lumen also drives the potassium reabsorption through the paracellular route.
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This question is part of the following fields:
- Physiology
- Renal
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Question 49
Incorrect
-
One of the benefits of wound healing through first intention is:
Your Answer: Reduced risk of foreign body in wound
Correct Answer: Minimisation of scar tissue formation
Explanation:Primary wound healing, or healing by first intention, occurs within hours of repairing a full-thickness surgical incision. This surgical insult results in the mortality of a minimal number of cellular constituents. Healing by first intention can occur when the wound edges are opposed, the wound is clean and uninfected and there is minimal loss of cells and tissue i.e. surgical incision wound. The wound margins are joined by fibrin deposition, which is subsequently replaced by collagen and covered by epidermal growth.
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This question is part of the following fields:
- Pathology
- Wound Healing
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Question 50
Correct
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Regarding endothelin-1, which of the following statements is INCORRECT:
Your Answer: Endothelin-1 release is inhibited by noradrenaline.
Explanation:Endothelin-1 (ET-1) is an extremely potent vasoconstrictor peptide which is released from the endothelium in the presence of many other vasoconstrictors, including angiotensin II, antidiuretic hormone (ADH) and noradrenaline, and may be increased in disease and hypoxia.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 51
Correct
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A young patient presents with the features of an easily recognisable infectious disease.Which of the following infectious diseases typically has an incubation period of less than 1 week? Select ONE answer only.
Your Answer: Cholera
Explanation:Cholera has an incubation period of 12 hours to 6 days.Other infectious disease that have an incubation period of less than 1 week include:Staphylococcal enteritis (1-6 hours)Salmonella enteritis (12-24 hours)Botulism (18-36 hours)Gas gangrene (6 hours to 4 days)Scarlet fever (1-4 days)Diphtheria (2-5 days)Gonorrhoea (3-5 days)Yellow fever (3-6 days)Meningococcaemia (1-7 days)Brucellosis has an incubation period of 7-21 days.Measles has an incubation period of 14-18 days.Falciparum malaria usually has an incubation period of 7-14 days. The other forms of malaria have a longer incubation period of 12-40 days.Rubella has an incubation period of 14-21 days.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 52
Correct
-
The neurotransmitter in the synaptic cleft is either eliminated or deactivated after the postsynaptic cell responds to the neurotransmitter.Which of the following enzymes catalyses the breakdown of noradrenaline?
Your Answer: Catechol-O-methyltransferase (COMT)
Explanation:The neurotransmitter in the synaptic cleft is either eliminated or deactivated after the post-synaptic cell responds to the neurotransmitter. This can be accomplished in a variety of ways:Re-uptakeBreakdownDiffusionSerotonin is an example of a neurotransmitter that is uptake. Serotonin is absorbed back into the presynaptic neuron via the serotonin transporter (SERT), which is found in the presynaptic membrane. Re-uptake neurotransmitters are either recycled by repackaging into vesicles or broken down by enzymes.Specific enzymes found in the synaptic cleft can also break down neurotransmitters. The following enzymes are examples of these enzymes:Acetylcholinesterase (AChE) catalyses the acetylcholine breakdown (ACh)The enzyme catechol-O-methyltransferase (COMT) catalyses the breakdown of catecholamines like adrenaline , dopamine and noradrenaline. The breakdown of catecholamines, as well as other monoamines like serotonin, tyramine, and tryptamine, is catalysed by monoamine oxidases (MOA).Diffusion of neurotransmitters into nearby locations can also be used to eliminate them.
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 53
Correct
-
In adult basic life support, chest compressions should be performed at which of the following rates:
Your Answer: 100 - 120 per minute
Explanation:Chest compressions should be performed at a rate of 100 – 120 per minute.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 54
Incorrect
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Identify the type of graph described below:This graph is a useful tool for evaluating the performance of diagnostic tests and more generally for evaluating the accuracy of a statistical model (e.g., logistic regression, linear discriminant analysis) that classifies subjects into 1 of 2 categories, diseased or non diseased. The closer the graph is to the upper left corner, which represents 100% sensitivity and 100% specificity, the more accurate the diagnostic test.
Your Answer: Forest plot
Correct Answer: ROC curve
Explanation:Receiver-operating characteristic (ROC) analysis was originally developed during World War II to analyse classification accuracy in differentiating signal from noise in radar detection. Recently, the methodology has been adapted to several clinical areas heavily dependent on screening and diagnostic tests, in particular, laboratory testing, epidemiology, radiology, and bioinformatics. ROC analysis is a useful tool for evaluating the performance of diagnostic tests and more generally for evaluating the accuracy of a statistical model (e.g., logistic regression, linear discriminant analysis) that classifies subjects into 1 of 2 categories, diseased or non diseased. Its function as a simple graphical tool for displaying the accuracy of a medical diagnostic test is one of the most well-known applications of ROC curve analysis.The closer the ROC curve is to the upper left corner, which has 100% sensitivity and 100% specificity, the higher the overall accuracy of the diagnostic test.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 55
Incorrect
-
A diagnosis of acute osteomyelitis was made on a patient with a known history of sickle cell disease. He has no joint prosthesis on in-dwelling metal work and no known drug allergies.Which of the following is most likely the causative agent of the case presented above?
Your Answer: Staphylococcus aureus
Correct Answer: Salmonella spp .
Explanation:Patients with sickle cell disease are prone to infection of the bone and bone marrow in areas of infarction and necrosis. Although Staphylococcus aureus is the most common cause of osteomyelitis in the general population, studies have shown that in patients with sickle cell disease, the relative incidence of Salmonella osteomyelitis is twice that of staphylococcal infection.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 56
Incorrect
-
Depolarisation of a neuron begins with which of the following:
Your Answer: Opening of voltage-gated Na + channels
Correct Answer: Opening of ligand-gated Na + channels
Explanation:Action potentials are initiated in nerves by activation of ligand-gated Na+channels by neurotransmitters. Opening of these Na+channels results in a small influx of sodium and depolarisation of the negative resting membrane potential (-70 mV). If the stimulus is sufficiently strong, the resting membrane depolarises enough to reach threshold potential (generally around -55 mV), at which point an action potential can occur. Voltage-gated Na+channels open, causing further depolarisation and activating more voltage-gated Na+channels and there is a sudden and massive sodium influx, driving the cell membrane potential to about +40 mV.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 57
Correct
-
Ipratropium bromide should be used with caution in patients with which of the following conditions:
Your Answer: Prostatic hyperplasia
Explanation:Ipratropium bromide is an antimuscarinic drug used in the management of acute asthma and COPD. It can provide short-term relief in chronic asthma, but short-acting β2agonists act more quickly and are preferred.The BTS guidelines recommend that nebulised ipratropium bromide (0.5 mg 4-6 hourly) can be added to β2agonist treatment for patients with acute severe or life-threatening asthma or those with a poor initial response to β2 agonist therapy.The aerosol inhalation of ipratropium can be used for short-term relief in mild chronic obstructive pulmonary disease in patients who are not already using a long-acting antimuscarinic drug (e.g. tiotropium).Its maximum effect occurs 30-60 minutes after use; its duration of action is 3-6 hours, and bronchodilation can usually be maintained with treatment three times per day.The commonest side effect of ipratropium bromide is dry mouth. It can also trigger acute closed-angle glaucoma in susceptible patients. Tremor is commonly seen with β2agonists but not with antimuscarinics. Ipratropium bromide should be used with caution in: Men with prostatic hyperplasia and bladder-outflow obstruction (worsened urinary retention has been reported in elderly men), People with chronic kidney disease (CKD) stages 3 and above (because of the risk of drug toxicity), People with angle-closure glaucoma (nebulised mist of antimuscarinic drugs can precipitate or worsen acute angle-closure glaucoma)
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 58
Correct
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You are attending to a patient that has presented with a severe headache in the Emergency Department. The patient has signs of cerebral oedema and raised intracranial pressure. You discuss the case with the on-call neurology registrar and decide to prescribe Mannitol. The nurse assisting you asks you to reconsider this management plan as she suspects the patient has a contraindication to Mannitol.Out of the following, what is a contraindication to mannitol?
Your Answer: Severe cardiac failure
Explanation:Mannitol is the most widely used osmotic diuretic that is most commonly used to reduce cerebral oedema and intracranial pressure. It is recommended to use mannitol for the reduction of CSF pressure/cerebral oedema in a dose of 0.25-2 g/kg as an intravenous infusion over 30-60 minutes. This can be repeated 1-2 times after 4-8 hours if needed.Mannitol has several contraindications and some of them are listed below:1. Anuria due to renal disease2. Acute intracranial bleeding (except during craniotomy)3. Severe cardiac failure4. Severe dehydration5. Severe pulmonary oedema or congestion6. Known hypersensitivity to mannitol
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 59
Correct
-
You've been summoned to a young man in the resus area who has an SVT. You decide to use adenosine after trying several vagal manoeuvres without success.The use of adenosine is not contraindicated in which of the following situations?
Your Answer: Concurrent use of a beta-blocker
Explanation:The use of a beta-blocker at the same time increases the risk of myocardial depression, but it is not a contraindication.The use of adenosine is contraindicated in the following situations:AsthmaCOPD (chronic obstructive pulmonary disease)Decompensated heart failure Long QT syndromeAV block in the second or third degreeSinusitis is a condition in which the sinuses become (unless pacemaker fitted)Hypotension that is severe
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 60
Correct
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The results from the study investigating the accuracy of a new diagnostic test can be displayed in the following format. How is the negative predictive value calculated:Those with diseaseThose without diseaseTotalTest positiveaba+bTest negativecdc+dTotala+cb+dn=a+b+c+d
Your Answer: d/(c+d)
Explanation:Negative predictive value (NPV) is the proportion of individuals with a negative test result who do not have the disease.NPV = d/(c+d)
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 61
Correct
-
Which of the following problems is associated with Helicobacter pylori infection?
Your Answer: Gastric malignancy
Explanation:Helicobacter pylori is a ubiquitous organism that is present in about 50% of the global population. Chronic infection with H pylori causes atrophic and even metaplastic changes in the stomach, and it has a known association with peptic ulcer disease. The most common route of H pylori infection is either oral-to-oral or faecal-to-oral contact.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 62
Correct
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A 50-year-old man presents with signs and symptoms of an anaphylactic reaction. His GP had recently given him a new medication.Which one of these is the most likely medication responsible for the drug-induced anaphylactic reaction?
Your Answer: Penicillin
Explanation:The most common cause of drug-induced anaphylaxis is penicillin.The second commonest cause are NSAIDs. Other drugs associated with anaphylaxis are ACE inhibitors and aspirin.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 63
Correct
-
Which cervical interspace is most likely injured if a patient presents with difficulty of shoulder abduction and elbow flexion, pain in the right shoulder and lateral arm, and decreased sensation over the deltoid and lateral arm?
Your Answer: C4-C5
Explanation:In the setting of cervical radiculopathy, because the nerve root of a spinal nerve is compressed or otherwise impaired, the pain and symptomatology can spread far from the neck and radiates to arm, neck, chest, upper back and/or shoulders. Often muscle weakness and impaired deep tendon reflexes are noted along the course of the spinal nerve.Cervical radiculopathy is almost always unilateral, although, in rare cases, both nerves at a given level may be impacted. Those rare presentations can confound physical diagnosis and require acceleration to advanced imaging especially in cases of trauma. If there is nerve impingement, the affected side will be reduced relative to the unaffected side. Reduction in strength of muscles innervated by the affected nerve is also significant physical finding.For a C4-C5 injury, the following symptoms may present:Weakness in the deltoid muscle (front and side of the shoulder) and upper armShoulder painNumbness along the outside of the upper arm
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 64
Correct
-
Regarding cortical areas, which one is found in the posterior part of the inferior frontal gyrus?
Your Answer: Broca’s area
Explanation:Broca’s area is involved in the expressive aspects of spoken and written language (production of sentences constrained by the rules of grammar and syntax). It corresponds to the opercular and triangular parts of the inferior frontal gyrus (BA 44 and 45). These areas are defined by two rami (branches) of the lateral sulcus (one ascending, one horizontal) which ‘slice into’ the inferior frontal gyrus. In keeping with its role in speech and language, Broca’s area is immediately anterior to the motor and premotor representations of the face, tongue and larynx. A homologous area in the opposite hemisphere is involved in non-verbal communication such as facial expression, gesticulation and modulation of the rate, rhythm and intonation of speech.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 65
Incorrect
-
Which of the following is most likely affected in De Quervain's tenosynovitis?
Your Answer: Abductor pollicis brevis
Correct Answer: Extensor pollicis brevis
Explanation:De Quervain tenosynovitis is named after the Swiss surgeon, Fritz de Quervain, who first described it in 1895. It is a condition which involves tendon entrapment affecting the first dorsal compartment of the wrist. With this condition thickening of the tendon sheaths around the abductor pollicis longus and extensor pollicis brevis develops where the tendons pass in through the fibro-osseous tunnel located along the radial styloid at the distal wrist. Pain is exacerbated by thumb movement and radial and ulnar deviation of the wrist.The estimated prevalence of de Quervain tenosynovitis is about 0.5% in men and 1.3% in women with peak prevalence among those in their forties and fifties. It may be seen more commonly in individuals with a history of medial or lateral epicondylitis. Bilateral involvement is often reported in new mothers or child care providers in whom spontaneous resolution typically occurs once lifting of the child is less frequent.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 66
Correct
-
A 25-year-old girl just got back from a trip to Northern India. She complains of headaches and intermittent fever. The fever starts with intense chills, then feels very hot, followed by profuse sweating. She is drowsy and is running a fever of 39.0°C. On examination, there are no palpable lymph nodes or rash seen. She has hepatosplenomegaly. Which one of the following is the most likely diagnosis?
Your Answer: Malaria
Explanation:Malaria is a protozoal infection of red blood cells and the liver. It is caused by the parasite belonging to the genus Plasmodium. It is transmitted by the female mosquito Anopheles.Several species with distinct features:P. vivax/P. ovaleP. malariaeP. falciparumThe common symptoms of malaria are:Paroxysms of fever – a cyclical occurrence of:1) a cold phase – the patient experiences intense chills2) a hot stage – the patient feels extremely hot3) a sweating stage – the fever declines and the patient sweats profusely- Fever recurs at regular intervals (48hrs, 72hrs): Variable by species of PlasmodiumAnaemia (RBC infection)- Severity varies by species of Plasmodium- Haemolytic: sometimes jaundiceSplenomegalyAlso nonspecific symptoms:- Sweating- fatigue- malaise- arthralgias- headache- Sometimes cough, vomiting, diarrhoea
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 67
Incorrect
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A 55-year-old woman with a known history of bronchiectasis has lung function testing carried out and is found to have significant airways obstruction.Which of the following lung volumes or capacities is LEAST likely to be decreased in this case? Select ONE answer only.
Your Answer: Expiratory reserve volume
Correct Answer: Functional residual capacity
Explanation:Obstructive lung disorders are characterised by airway obstruction. Many obstructive diseases of the lung result from narrowing of the smaller bronchi and larger bronchioles, often because of excessive contraction of the smooth muscle itself.In obstructive lung disease, FEV1is reduced to <80% of normal and FVC is usually reduced but to a lesser extent than FEV1. The FEV1/FVC ratio is reduced to 80% in the presence of symptomsModerate airflow obstruction = FEV1of 50-79%Severe airflow obstruction = FEV1of 30-49%Very severe airflow obstruction = FEV1<30%.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 68
Correct
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Which of the following is NOT a common side effect of antihistamines:
Your Answer: Tremor
Explanation:Common side effects of antihistamines may include:Anticholinergic effects (blurred vision, dry mouth, urinary retention)HeadacheGastrointestinal disturbancesPsychomotor impairment (sedation, dizziness and loss of appetite)These side effects are significantly reduced with second-generation agents.
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 69
Correct
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Regarding Legionella species which of the following statements is CORRECT:
Your 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 daysCough (usually non-productive and occurs in approximately 90%)Pleuritic chest painHaemoptysisHeadacheNausea, vomiting and diarrhoeaAnorexiaLegionella 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.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 70
Correct
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Which statement accurately describes the osmolality in the various parts of the Henle Loop?
Your Answer: The osmolality of fluid in the descending loop equals that of the peritubular fluid
Explanation:The Loop of Henle connects the proximal tubule to the distal convoluted tubule and lies parallel to the collecting ducts. It consists of three major segments, including the descending thin limb, the ascending thin limb, and the ascending thick limb. These segments are differentiated based on structure, anatomic location, and function. The main function of the loop of Henle is to recover water and sodium chloride from urine. When fluid enters the loop of Henle, it has an osmolality of approximately 300 mOsm, and the main solute is sodium. The thin descending limb has a high water permeability but a low ion permeability. Because it lacks solute transporters, it cannot reabsorb sodium. Aquaporin 1 (AQP1) channels are used to passively absorb water in this area. The peritubular fluid becomes increasingly concentrated as the loop descends into the medulla, causing water to osmose out of the tubule. The tubular fluid in this area now equalizes to the osmolality of the peritubular fluid, to a maximum of approximately 1200 mOsm in a long medullary loop of Henle and 600 mOsm in a short cortical loop of Henle. The thin ascending limb is highly permeable to ions and impermeable to water. It allows the passive movement of sodium, chloride, and urea down their concentration gradients, so urea enters the tubule and sodium and chloride leave. Reabsorption occurs paracellularly due to the difference in osmolarity between the tubule and the interstitium. The thick ascending limb is also impermeable to water but actively transports sodium, potassium, and chloride out of the tubular fluid. The osmolality of the tubular fluid is lower compared to the surrounding peritubular fluid. This area is water impermeable. This results in tubular fluid leaving the loop of Henle with an osmolality of approximately 100 mOsm, which is lower than the osmolality of the fluid entering the loop, and urea being the solute.
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 71
Correct
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Arterial baroreceptors are located primarily in which of the following:
Your Answer: Carotid sinus and aortic arch
Explanation:Arterial baroreceptors are located in the carotid sinus and aortic arch, and detect the mean arterial pressure (MAP). A decrease in MAP (such as in postural hypotension, or haemorrhage) reduces arterial stretch and decreases baroreceptor activity, resulting in decreased firing in afferent nerves travelling via the glossopharyngeal nerve (carotid sinus) and vagus nerve (aortic arch) to the medulla where the activity of the autonomic nervous system is coordinated. Sympathetic nerve activity consequently increases, causing an increase in heart rate and cardiac contractility, peripheral vasoconstriction with an increase in TPR, and venoconstriction with an increase in CVP and thus an increase in cardiac output and blood pressure. Parasympathetic activity (vagal tone) decreases, contributing to the rise in heart rate.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 72
Correct
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You review a 37-year-old man with a history of intravenous drug abuse who admits to sharing needles in the past. He has a flu-like illness and a rash. Concerned he may be experiencing an HIV seroconversion illness, you order a test.Which of these tests is most reliably used to diagnose HIV at this stage?
Your Answer: p24 antigen test
Explanation:Serum concentrations of the p24 antigen are usually high in the first few weeks after human immunodeficiency virus (HIV) infection and testing for p24 antigen is therefore a useful way of diagnosing very early infection. P24 is the viral protein that makes up most of the core of the HIV.ELISA and other antibody tests, though a very sensitive way of detecting the presence of HIV, cannot be used in the early stages of the disease. This is because of the window period of 6-12 weeks before antibodies are produced. These tests will be negative during a seroconversion illness.The ‘rapid HIV test’ is an HIV antibody test. It will also be negative during the ‘window period’ since it takes time for antibodies to be produced. It is called the ‘rapid test’ as it can detect antibodies in blood or saliva much quicker than the other antibody tests and results are often back within 20 minutes.CD4 and CD8 counts are usually normal in the early stages of the HIV infection and cannot be used in this case.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 73
Correct
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Which of the following nerves is most likely associated with an anterior shoulder dislocation?
Your Answer: Axillary nerve
Explanation:In an anterior dislocation, the arm is an abducted and externally rotated position. In the externally rotated position, the posterosuperior aspect of the humeral head abuts and drives through the anteroinferior aspect of the glenoid rim. This can damage the humeral head, glenoid labrum, or both. An associated humeral head compression fracture is described as a Hill Sach’s lesion. If large enough, it can lead to locked dislocations that may require open reduction. The glenoid labrum is a fibrocartilaginous structure that rings the circumference of the glenoid fossa. Bankart lesions are injuries to the anteroinferior glenoid labrum complex and the most common capsulolabral injury. A bony Bankart lesion refers to an associated fracture of the glenoid rim. These capsulolabral lesions are risk factors for recurrent dislocation.Axillary nerve injury is identified in about 42% of acute anterior shoulder dislocations. Nerve transection is rare, and traction injuries are more common. Arterial injury has also been described. The subclavian artery becomes the axillary artery after passing the first rib. The distal portion of the axillary artery is anatomically fixed and, therefore, susceptible to injury in anterior dislocations. Ischemic injury, including pseudoaneurysm and arterial laceration, is rare but carries marked morbidity if not quickly identified.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 74
Correct
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Which of the following statements about lithium treatment is FALSE:
Your Answer: Concomitant treatment with NSAIDs decreases serum-lithium concentration.
Explanation:Lithium levels are raised by NSAIDs because renal clearance is reduced. Lithium is a small ion (74 Daltons) with no protein or tissue binding and is therefore amenable to haemodialysis. Lithium is freely distributed throughout total body water with a volume of distribution between 0.6 to 0.9 L/kg, although the volume may be smaller in the elderly, who have less lean body mass and less total body water. Steady-state serum levels are typically reached within five days at the usual oral dose of 1200 to 1800 mg/day. The half-life for lithium is approximately 18 hours in adults and 36 hours in the elderly.Lithium is excreted almost entirely by the kidneys and is handled in a manner similar to sodium. Lithium is freely filtered but over 60 percent is then reabsorbed by the proximal tubules.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 75
Correct
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When the breast cancer of a 60-year old patient metastasizes and compresses the intervertebral foramina between the fourth and fifth cervical vertebrae, as well as the fourth and fifth thoracic vertebrae, this causes back pain. Which pair of nerves is most likely affected?
Your Answer: Fifth cervical and fourth thoracic nerves
Explanation:The fifth cervical nerve passes between the fourth and fifth cervical vertebrae, and the fourth thoracic nerve passes between the fourth and fifth thoracic vertebrae. Therefore, when the cancer metastasizes in this area, they are most likely affected.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 76
Correct
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A trauma victim who has been intubated is tachycardic, hypotensive, and has a poor urine output. You feel she is dehydrated and decide to use a central venous catheter to help you manage her. As part of this, you keep an eye on the waveform of central venous pressure (CVP).Which of the following cardiac cycle phases corresponds to the CVP waveform's 'a wave'?Â
Your Answer: End diastole
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).The structure of the CVP waveform is as follows:The CVP’s components are listed in the table below:Component of the waveformThe cardiac cycle phase.mechanical eventmechanical event Diastole Atrial contractiona wave C  wave v waveEarly systoleThe tricuspid valve closes and bulges Late Systole Filling of the atrium with systolic blood x descenty descentMid systoleRelaxation of the atrium Early diastoleFilling of the ventricles at an early stage
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This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
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Question 77
Incorrect
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On ambulatory blood pressure monitoring, a 48-year-old Caucasian man has an average BP reading of 152/96 mmHg (ABPM).Which of the following would be the patient's first-line drug treatment?
Your Answer: Amlodipine
Correct Answer: Ramipril
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 48-year-old Afro-Caribbean man.An ACE inhibitor, such as ramipril, or a low-cost angiotensin-II receptor blocker (ARB), such as losartan, would be the most appropriate medication for a 48-year-old Caucasian man.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 78
Correct
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Regarding likelihood ratios, which of the following statements is INCORRECT:
Your Answer: Likelihood ratios, like predictive values, are affected by the prevalence of the disease in the population.
Explanation:A likelihood ratio is a measure of the diagnostic value of a test. Likelihood ratios show how many times more likely patients with a disease are to have a particular test result than patients without the disease. Likelihood ratios are more useful than predictive values because they are calculated from sensitivity and specificity and therefore remain constant even when the prevalence of the disorder changes.
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 79
Correct
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CSF is reabsorbed from subarachnoid space via which of the following structures:
Your Answer: Arachnoid granulations
Explanation:From the subarachnoid cisterns in the subarachnoid space, CSF is reabsorbed via arachnoid granulations which protrude into the dura mater, into the dural venous sinuses and from here back into the circulation.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 80
Correct
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Which of the following is true about the extensor carpi radialis longus?
Your Answer: It assists with abduction of the hand at the wrist
Explanation:The majority of extensor carpi radialis longus originates from the lateral supracondylar ridge of humerus (distal third) and anterior aspect of the lateral intermuscular septum of the arm. A small portion of its fibres originate from the common extensor tendon attached to the lateral epicondyle of humerus. The fibres unite into a muscle belly which extends approximately to the middle of the forearm. The muscle belly is then replaced by a flat tendon that travels distally along the lateral surface of the radius, together with the tendon of extensor carpi radialis brevis. Both tendons course towards the radial styloid process, deep to the tendons of abductor pollicis longus and extensor pollicis brevis muscles. Proximal to the wrist, the tendons of extensor carpi radialis longus and brevis pass behind the radial styloid process within a common synovial sheath and continue along the radial groove deep to the extensor retinaculum of the wrist. At this level, the tendon of extensor carpi radialis longus is crossed by the tendon of extensor pollicis longus, after which it inserts on the posterior aspect of the base of the second metacarpal bone. Some tendon slips can insert into the first and third metacarpal bones.Extensor carpi radialis longus receives innervation from the radial nerve, with contributions mainly from spinal nerves C5-C8. The radial nerve is a branch of the brachial plexus.Extensor carpi radialis longus receives blood supply mainly from the radial artery. It directly supplies the distal part of the muscle, while the rest of the muscle receives blood from one of its radial recurrent branches. The brachial artery also supplies a small portion of the muscle via the radial collateral artery.Extensor carpi radialis longus primarily acts on the wrist joint to produce two major actions: (1) wrist extension by working synergistically with extensor carpi radialis brevis and extensor carpi ulnaris, and (2) hand abduction (radial deviation), with the help of flexor carpi radialis.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 81
Incorrect
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A dermatological examination on a patient presenting with a lump shows a solid, well circumscribed, lump measuring 0.8 cm in diameter.Which one of these best describes the lump you have found on examination?
Your Answer: Papule
Correct Answer: Nodule
Explanation:A nodule is a solid, well circumscribed, raised area that lies in or under the skin and measures greater than 0.5 cm in diameter. They are usually painless.A vesicle is a visible collection of fluid measuring less than 0.5 cm in diameter. A macule is a flat, well circumscribed area of discoloured skin less than 1 cm in diameter with no changes in the thickness or texture of the skin.A papule is a solid, well circumscribed, skin elevation measuring less than 0.5 cm in diameter.A plaque is a palpable skin lesion that is elevated and measures >1cm in diameter
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 82
Correct
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You are examining the lower limbs of a 54 year old man who presented after falling from a ladder at home. During your neurological assessment you note a weakness of hip flexion. Which of the following nerves is the most important for flexion of the thigh at the hip joint:
Your Answer: Femoral nerve
Explanation:Flexion of the thigh at the hip joint is produced by the sartorius, psoas major, iliacus and pectineus muscles, assisted by the rectus femoris muscle, all innervated by the femoral nerve (except for the psoas major, innervated by the anterior rami of L1 – 3).
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 83
Correct
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A patient who has a nerve injury has sparing of the upper half of the orbicularis oculi muscle but not the lower half. Which branch of the facial nerve supplies the lower half of the orbicularis oculi?
Your Answer: Zygomatic branch
Explanation:The facial nerve divides into five terminal branches once in the parotid gland. 1. The temporal branch innervates muscles in the temple, forehead and supraorbital areas.2. The zygomatic branch innervates muscles in the infraorbital area, the lateral nasal area and the upper lip.3. The buccal branch innervates muscles in the cheek, the upper lip and the corner of the mouth. 4. The marginal mandibular branch innervates muscles of the lower lip and chin. 5. The cervical branch innervates the platysma muscle.
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This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
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Question 84
Incorrect
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Which of the following medications may lessen warfarin's anticoagulant effect:
Your Answer: Metronidazole
Correct Answer: Phenytoin
Explanation:Phenytoin will decrease the level or effect of warfarin by affecting hepatic/intestinal enzyme CYP3A4 metabolism.Metronidazole will increase the level or effect of warfarin by affecting hepatic enzyme CYP2C9/10 metabolism.NSAIDs, when given with Warfarin, increase anticoagulation.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 85
Correct
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A young man develops an infection spread via aerosol transmission.Which of these organisms is commonly spread by aerosol transmission?
Your Answer: Measles virus
Explanation:Aerosols are airborne particles less than 5 µm in size, containing infective organisms that usually cause infection of the upper or lower respiratory tract.Examples of organisms commonly spread by aerosol transmission are:Measles virusVaricella zoster virusMycobacterium tuberculosisThe following table summarises the various routes of transmission with example organisms:Route of transmissionExample organismsAerosol (airborne particle < 5 µm)Mycobacterium tuberculosisVaricella zoster virusMeasles virusHepatitis A and Rotavirus are spread by the faeco-oral route.Neisseria gonorrhoea is spread by sexual route.Staphylococcus aureus is spread by direct contact.
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 86
Correct
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Question 87
Incorrect
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The enzyme protein gastric lipase is responsible for the breakdown of lipids in the stomach.Which of the following cell types secretes gastric lipase?Â
Your Answer: G-cells
Correct Answer: Chief cells
Explanation:Gastric lipase, commonly known as LIPF, is an acidic lipase released by gastric chief cells, which are found deep within the stomach lining’s mucosal layer. It’s an enzymatic protein that’s in charge of fat digestion in the stomach.
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This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 88
Correct
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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: 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 rearrangementsEpstein-Barr virus infectionHuman T-cell leukaemia virus type-1 (HTLV-1)Hepatitis CCongenital and acquired immunodeficiency statesAutoimmune disorders, e.g. Sjogren’s syndrome and Hashimoto’s thyroiditis
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This question is part of the following fields:
- Haematology
- Pathology
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Question 89
Incorrect
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A 23-year-old male is referred to your haematology clinic after an acute attack of haemolytic anaemia. He was diagnosed with glucose-6-phosphate dehydrogenase deficiency ten years ago. Which ONE of the following options is FALSE with regards to this disorder?
Your Answer: It shows X-linked recessive inheritance
Correct Answer: Acute haemolysis can be triggered by cephalosporin antibiotics
Explanation:Glucose-6-phosphate dehydrogenase deficiency is an X-linked recessive disorder in which there is a deficiency of the enzyme G6PD. This causes instability of red blood cell membranes under oxidative stress leading to haemolysis.Triggers include: 1) Fava beans2) Sulphonamides3) Primaquine4) Anti-TB drugs5) Infections Most individuals will be asymptomatic until exposed to one of the triggers listed above. It is the commonest human enzyme defect and affects males more than females because of the X-linked inheritance pattern. The use of penicillins and cephalosporins is generally safe.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 90
Incorrect
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A patient presents with a history of renal problems, generalised weakness and palpitations. Her serum potassium levels are measured and come back at 6.2 mmol/L. An ECG is performed, and it shows some changes that are consistent with hyperkalaemia.Which of the following ECG changes is usually the earliest sign of hyperkalaemia? Select ONE answer only.
Your Answer: Prolonged PR segment
Correct Answer: Peaked T waves
Explanation:Hyperkalaemia causes a rapid reduction in resting membrane potential leading to increased cardiac depolarisation and muscle excitability. This in turn results in ECG changes which can rapidly progress to ventricular fibrillation or asystole. Very distinctive ECG changes that progressively change as the K+level increases:K+>5.5 mmol/l – peaked T waves (usually earliest sign of hyperkalaemia), repolarisation abnormalitiesK+>6.5 mmol/l – P waves widen and flatten, PR segment lengthens, P waves eventually disappearK+>7.0 mmol/l – Prolonged QRS interval and bizarre QRS morphology, conduction blocks (bundle branch blocks, fascicular blocks), sinus bradycardia or slow AF, development of a sine wave appearance (a pre-terminal rhythm)K+>9.0 mmol/l – Cardiac arrest due to asystole, VF or PEA with a bizarre, wide complex rhythm.
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 91
Incorrect
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Regarding codeine, which of the following statements is INCORRECT:
Your Answer: Codeine 240 mg is approximately equivalent to 30 mg of morphine.
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.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 92
Incorrect
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Which of these immunoglobulin molecules can cross the placenta?
Your Answer: IgM
Correct Answer: IgG
Explanation:An important mechanism that provides protection to the foetus is placental transfer of maternal IgG antibodies while his/her humoral response is inefficient. The only antibody class that significantly crosses the human placenta is IgG.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 93
Correct
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Regarding the human cell, which of the following cell organelles is responsible for the production of ATP:
Your Answer: Mitochondria
Explanation:Mitochondria are membrane-bound organelles that are responsible for the production of the cell’s supply of chemical energy. This is achieved by using molecular oxygen to utilise sugar and small fatty acid molecules to generate adenosine triphosphate (ATP). This process is known as oxidative phosphorylation and requires an enzyme called ATP synthase. ATP acts as an energy-carrying molecule and releases the energy in situations when it is required to fuel cellular processes. Mitochondria are also involved in other cellular processes, including Ca2+homeostasis and signalling. Mitochondria contain a small amount of maternal DNA.Mitochondria have two phospholipid bilayers, an outer membrane and an inner membrane. The inner membrane is intricately folded inwards to form numerous layers called cristae. The cristae contain specialised membrane proteins that enable the mitochondria to synthesise ATP. Between the two membranes lies the intermembrane space, which stores large proteins that are required for cellular respiration. Within the inner membrane is the perimitochondrial space, which contains a jelly-like matrix. This matrix contains a large quantity of ATP synthase.Mitochondrial disease, or mitochondrial disorder, refers to a group of disorders that affect the mitochondria. When the number or function of mitochondria in the cell are disrupted, less energy is produced and organ dysfunction results.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 94
Incorrect
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Which of the following serology results is consistent with chronic hepatitis B infection:
Your Answer: HBsAg positive and anti-HBc IgM positive
Correct Answer: HBsAg positive and anti-HBc IgG positive
Explanation:Disease state vs SerologyAcute hepatitis: BHBsAg, HBeAg, anti-HBc IgMChronic hepatitis B (low infectivity): HBsAg (>6/12), anti-HBe, anti-HBc IgGChronic hepatitis B (high infectivity): HBsAg (>6/12), HBeAg, anti-HBc IgGCleared infection: Anti-HBs, anti-HBe, anti-HBc IgGVaccinated: Anti-HBs
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 95
Incorrect
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Fracture of the medial epicondyle would result to the following, except
Your Answer: Weakness of wrist flexion
Correct Answer: Weakness of abduction of the thumb
Explanation:Thumb abduction is mediated by the abductor pollicis longus and brevis, which are innervated by the radial and median nerves, respectively.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 96
Correct
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Injury to which nerve can lead to weakness or paralysis of the brachialis muscle?
Your 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).
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 97
Incorrect
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In the Paediatric Emergency Department, you saw a 6-year-old girl with severe bilateral conjunctivitis. You give her mother some general eye hygiene advice and prescribe chloramphenicol eye drops.What is the chloramphenicol's mechanism of action?
Your Answer: Inhibition of nucleic acid synthesis
Correct Answer: Inhibition of protein synthesis
Explanation:Chloramphenicol is a broad-spectrum antibiotic that inhibits bacterial protein synthesis by blocking the 50S subunit of the bacterial ribosome’s peptidyl transferase activity. When administered systemically, it has limited usage due to the potential of significant side effects such as aplastic anaemia, peripheral neuropathy, and optic neuritis. It’s only used to treat typhoid fever and Haemophilus influenzae meningitis, but it’s usually better to use a broad-spectrum cephalosporin.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 98
Correct
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Question 99
Correct
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Which of the following side effects is more common of etomidate than other intravenous induction agents:
Your Answer: Extraneous muscle movements
Explanation:Etomidate is associated with a high incidence of extraneous muscle movements, which can be minimised by an opioid analgesic or a short-acting benzodiazepine given prior to induction. Etomidate causes less hypotension than thiopental sodium and propofol during induction. Etomidate is associated with rapid recovery without a hangover effect. The rate of respiratory depression and tachycardia is not higher in etomidate.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 100
Correct
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A newborn baby girl is delivered vaginally to a 19-year old female, however with complications due to cephalopelvic disproportion. Upon examination by the attending paediatrician, there is a notable 'claw hand' deformity of the left, and sensory loss of the ulnar aspect of the left distal upper extremity.What is the most probable diagnosis of the case above?
Your Answer: Klumpke’s palsy
Explanation:Klumpke palsy, named after Augusta Dejerine-Klumpke, is a neuropathy involving the lower brachial plexus. In contrast, the more common Erb–Duchenne palsy involves the more cephalic portion of the brachial plexus C5 to C6. The brachial plexus is a bundle of individual nerves that exit between the anterior and middle scalene muscles in the anterior lateral and basal portion of the neck. Although the most common anatomical presentation of the brachial plexus is between the anterior and middle scalene, there are variations, with the most common being penetration of the anterior scalene. The main mechanism of injury to the lower brachial plexus is hyper-abduction traction, and depending on the intensity, it will lead to signs and symptoms consistent with a neurological insult.The most common aetiology resulting in Klumpke palsy is a hyper-abduction trauma to the arm that has enough intensity to traction the lower brachial plexus. Trauma during birth can cause brachial plexus injuries, but again hyper-abduction and traction forces to the upper extremity are usually present.The history presented by the patient usually depicts a long axis hyper-abduction traction injury with high amplitude and velocity. The typical patient presentation is a decrease of sensation along the medial aspect of the distal upper extremity along the C8 and T1 dermatome. The patient might also present myotome findings that can range from decreasing muscular strength to muscular atrophy and positional deformity. For example, if the neurological damage has led to muscular atrophy and tightening, the patient may present with a claw hand. This deformity presents a finger and wrist flexion. The patient may also describe the severe pain that starts at the neck and travels down the medial portion of the arm. One other sign of a lower brachial plexus injury is Horner syndrome; because of its approximation to the T1 nerve root, it may damage the cephalic sympathetic chain. If this happens, the patient will develop ipsilateral ptosis, anhidrosis, and miosis.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 101
Incorrect
-
Fat necrosis is typically seen in which of the following:
Your Answer: Malignant hypertension
Correct Answer: Acute pancreatitis
Explanation:Fat necrosis typically occurs following either direct trauma or from enzymatic lipolysis in acute pancreatitis, where release of triglyceride elicits a rapid inflammatory response and fat is phagocytosed by neutrophils and macrophages with subsequent fibrosis.
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This question is part of the following fields:
- Inflammatory Responses
- Pathology
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Question 102
Incorrect
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A 61-year-old woman returns to get the results of recent blood tests she had done for non-specific malaise, lethargy, and weight loss. The only abnormality discovered during the blood tests was a 580 x 10 9 /l increase in platelets. Her platelets were also elevated on a blood test taken 6 months earlier, according to her previous results. You're aware of the recent emergence of elevated platelet levels as a cancer risk marker and decide to look into it.Which of the following cancers is most likely to cause isolated thrombocytosis?
Your Answer: Multiple myeloma
Correct Answer: Colorectal cancer
Explanation:Raised platelet levels have emerged as a cancer risk marker, according to a large population-based study published in 2017(link is external). According to the study, 12 percent of men and 6% of women with thrombocytosis were diagnosed with cancer within a year. These figures increased to 18% in men and 10% in women if a second platelet count was taken within 6 months of the first and showed an increased or stable elevated platelet count.The researchers discovered that thrombocytosis linked to cancer is most common in colorectal and lung cancers, and it is linked to a worse prognosis. Furthermore, one-third of the cancer patients in the study had no other symptoms that would have prompted an immediate cancer referral.The exact mechanism by which these cancers cause thrombocytosis is unknown, but one theory proposes the existence of pathogenic feedback loops between malignant cells and platelets, with a reciprocal interaction between tumour growth and metastasis, as well as thrombocytosis and platelet activation. Another hypothesis is that thrombocytosis occurs independently of cancer but aids in its spread and progression.The findings show that routinely testing for thrombocytosis could cut the time it takes to diagnose colorectal and lung cancer by at least two months. In the UK, this could result in around 5500 earlier cancer diagnoses per year.Because the positive predictive value of thrombocytosis in middle age for cancer (10%) is higher than the positive predictive value for a woman in her 50s presenting with a new breast lump (8.5%), this is clearly an important research paper that should be used to adjust future clinical practise. The current NICE guidelines predate these new research findings, so we’ll have to wait and see how they affect cancer referral guidelines in the UK.Because there are so many possible cancers associated with thrombocytosis, the treating clinician should take a thorough history and perform a thorough clinical examination if a patient is diagnosed with it. Further investigation and the most appropriate referral route should be aided by this information.It’s worth noting that the patients in the study had their blood tests done for a medical reason rather than as a random screening test.If there are no other symptoms to guide investigation and referral (one-third of the patients in the study had no other symptoms), keep in mind that the two most common cancers encountered were colorectal and lung cancer, so a chest X-ray and a faecal immunochemical test (FIT) for faecal blood may be reasonable initial investigations.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 103
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: 1.0 L
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.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 104
Correct
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One of your patients is in resuscitation and is suffering from kidney failure. The intensive care outreach team arrives to assess them and determines that a dopamine infusion is necessary.Dopamine primarily acts on which of the following receptors at low doses?
Your Answer: Dopamine receptors
Explanation:Dopamine is a catecholamine that occurs naturally and is used to treat low cardiac output, septic shock, and renal failure. It is both adrenaline and noradrenaline’s immediate precursor.Dopamine acts on D1 and D2 dopamine receptors in the renal, mesenteric, and coronary beds at low doses (1-5 g/kg/min). Dopamine causes a significant decrease in renal vascular resistance and an increase in renal blood flow at these doses. Within this dose range, it is also involved in central modulation of behaviour and movement.Dopamine stimulates beta- and alpha-adrenergic receptors directly and indirectly at higher doses. Beta-stimulation predominates at a rate of 5-10 g/kg/min, resulting in a positive inotropic effect that increases cardiac output and coronary blood flow. Alpha-stimulation predominates at infusion rates greater than 15 g/kg/min, resulting in peripheral vasoconstriction and an increase in venous return and systolic blood pressure.Below is a summary of the mechanisms and effects of various inotropic agents:InotropeMechanismEffectsAdrenaline (epinephrine)Beta-1 and -2 agonist at increasing doses;Alpha-agonist at high dosesIncreased cardiac output;Vasoconstriction at higher dosesNoradrenaline (norepinephrine)Mainly alpha-agonist;Beta-1 and -2 agonist at increasing dosesVasoconstriction;Some increased cardiac outputDopamineDopamine agonist at low doses;Beta-1 and -2 agonist at increasing doses;Alpha-agonist at high dosesIncreased cardiac output;Vasoconstriction at higher dosesDobutamineMainly beta-1 agonistIncreased cardiac output
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 105
Correct
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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: 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.
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 106
Correct
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You are about to perform an emergency pericardiocentesis on a 26-year-old male who was involved in a car accident and is suspected of having cardiac tamponade due to signs of hypotension, muffled heart sounds, and distended neck veins. Where should you insert the needle to relieve tamponade?
Your Answer: Inferior and to the left of the xiphochondral junction
Explanation:Pericardiocentesis is a procedure that removes excess fluid from the pericardium. As a result, it’s used in cases of cardiac tamponade, which occurs when there’s too much fluid in the space around the heart. During the procedure, a needle and a small catheter are inserted 1 to 2 cm inferior and to the left of the xiphochondral junction into the pericardial cavity.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 107
Correct
-
An increased anion gap metabolic acidosis is typically caused by which of the following?
Your Answer: Propylene glycol overdose
Explanation:Causes of a raised anion gap acidosis can be remember using the mnemonic MUDPILES:-Methanol-Uraemia (in renal failure)-Diabetic ketoacidosis-Propylene glycol overdose-Infection/Iron overdose/Isoniazid/Inborn errors of metabolism-Lactic acidosis-Ethylene glycol overdose-Salicylate overdose
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This question is part of the following fields:
- Physiology
- Renal
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Question 108
Correct
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What is the pathophysiology of a phaeochromocytoma:
Your Answer: Catecholamine-secreting tumour
Explanation:Phaeochromocytomas are catecholamine-secreting tumours which occur in about 0.1% of patients with hypertension. In about 90% of cases they arise from the adrenal medulla. The remaining 10%, which arise from extra-adrenal chromaffin tissue, are termed paragangliomas. Common presenting symptoms include one or more of headache, sweating, pallor and palpitations. Less commonly, patients describe anxiety, panic attacks and pyrexia. Hypertension, whether sustained or episodic, is present in at least 90% of patients. Left untreated phaeochromocytoma can occasionally lead to hypertensive crisis, encephalopathy, hyperglycaemia, pulmonary oedema, cardiac arrhythmias, or even death.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 109
Incorrect
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Which of the following is characterised by passive carrier-mediated transport down a chemical concentration gradient:
Your Answer: Secondary active transport
Correct Answer: Facilitated diffusion
Explanation:Facilitated diffusion is the process of spontaneous passive transport of molecules or ions down their concentration gradient across a cell membrane via specific transmembrane transporter (carrier) proteins. The energy required for conformational changes in the transporter protein is provided by the concentration gradient rather than by metabolic activity.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 110
Correct
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A 71-year-old patient has been diagnosed with a dopamine-secreting neuroendocrine tumour.Which of the following statements about dopamine is correct?
Your Answer: It inhibits prolactin release from the anterior pituitary
Explanation:Dopamine is a neurotransmitter and amine hormone that is derived from the amino acid tyrosine. It is made in a number of places throughout the human body, both inside and outside the central nervous system. The adrenal medulla, dopamine neurons in the arcuate nucleus of the hypothalamus, the substantia nigra, and other areas of the brain produce dopamine.The tuberoinfundibular pathway refers to the dopamine neurons in the arcuate nucleus of the hypothalamus’ tubeal region. Dopamine is discharged into the hypothalamo-hypophyseal portal system from these neurons’ neurosecretory terminals at the median eminence.The major function of dopamine produced from the hypothalamus is to suppress prolactin production from the anterior pituitary, and it is released in reaction to excessive levels of prolactin secretion. Modulation of motor-control centres and activation of reward centres are two more crucial activities of the brain.Dopamine-secreting cells can also be found in other areas of the body, where they perform mostly paracrine functions (acting on nearby cells).
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 111
Incorrect
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A 62-year-old man complains of chest pain and goes to the emergency room. You diagnose him with an acute coronary syndrome and prescribe enoxaparin as part of his treatment plan.Enoxaparin inactivates which of the following?
Your Answer: Antithrombin III
Correct Answer: Thrombin
Explanation:Enoxaparin is a low molecular weight heparin (LMWH) that works in the same way as heparin by binding to and activating the enzyme inhibitor antithrombin III. Antithrombin III inactivates thrombin by forming a 1:1 complex with it. Factor Xa and a few other clotting proteases are also inhibited by the heparin-antithrombin III complex.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 112
Correct
-
The pelvic bone is formed by which of the following:
Your Answer: Ilium, ischium and pubis
Explanation:Each pelvic bone is formed by three elements: the ilium (superiorly), the pubis (anteroinferiorly) and the ischium (posteroinferiorly).
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 113
Correct
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The patient is a 61-year-old man with severe central chest pain. An acute myocardial infarction is revealed by his ECG. Clopidogrel is one of the medications he takes as part of his treatment.Clopidogrel's direct mechanism of action is which of the following?
Your Answer: Inhibition of platelet ADP receptors
Explanation:Clopidogrel, a thienopyridine derivative, prevents platelet aggregation and cross-linking by the protein fibrin by inhibiting the ADP receptor on platelet cell membranes (inhibits binding of ADP to its platelet receptor (P2Y12 ADP-receptor).
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 114
Correct
-
You are treating a patient with a Clostridium difficile infection. His condition was found to be antibiotic-associated. Which of the following pieces of advice on preventing the spread of this disease should you give this patient?
Your Answer: Washing hands with soap and water
Explanation:Clostridium difficile (C. diff) can cause colitis, or inflammation of the colon. To prevent its spread, one should practice good hand hygiene, regularly clean areas of the home that may become contaminated with C. difficile, practice good hand hygiene, and clean surfaces, spills, and accidents.
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This question is part of the following fields:
- Microbiology
- Principles
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Question 115
Correct
-
In which of the following cases is intravenous phenytoin contraindicated?
Your Answer: Second degree heart block
Explanation:Phenytoin Contraindications include:HypersensitivitySinus bradycardiaSinoatrial blockSecond and third degree A-V blockAdams-Stokes syndromeConcurrent use with delavirdineHistory of prior acute hepatotoxicity attributable to phenytoin
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 116
Incorrect
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EMLA cream is a topical local anaesthetic containing which of the following:
Your Answer: 50/50 mixture 2.5% lidocaine and 2.5% bupivacaine
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.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 117
Correct
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Question 118
Correct
-
A 33 year old female patient presents to emergency room with some symptoms that she thinks might be due to a drug that she has recently started. She was started on hyoscine butyl bromide for symptomatic relief of irritable bowel syndrome. The least likely expected side effect of this drug in this patient is:
Your Answer: Diarrhoea
Explanation:One of the commonest antispasmodic medications that is used is hyoscine butylbromide. It is an antimuscarinic and typical side effects of this class of drugs include:- dilation of pupils with loss of accommodation (cycloplegia) -photophobia resulting in blurred vision (Blind as a bat) -dry mouth, eyes and skin (Dry as a bone), -elevated temperature (Hot as a hare)-skin flushing (Red as a beet)-confusion or agitation particularly in the elderly (Mad as a hatter)-reduced bronchial secretions-transient bradycardia followed by tachycardia, palpitation and arrhythmias-urinary retention and/or constipation
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This question is part of the following fields:
- Gastrointestinal
- Pharmacology
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Question 119
Correct
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A 71-year-old man treated with antibiotics for a chest infection returns with a profuse, offensive smelling diarrhoea. A diagnosis of Clostridium difficile diarrhoea is made after investigations.The action most effective at minimizing spread to other patients is?
Your Answer: Hand washing
Explanation:Clostridium difficile, a Gram-positive, anaerobic, spore forming bacteria is present in the gut of approximately 3% of healthy adults (2012 UK HPA estimates). Following use of broad spectrum antibiotics, which alter normal gut flora, Clostridium difficile associated diarrhoea (CDAD) occurs.Alcohol hand gel is not effective against Clostridium Difficile spores. Hand washing with soap and water is very essential for healthcare workers who come in contact with it.Wearing an apron and gloves, and isolation to a side room are important contact precautions. They are, however, ineffective if hand washing is neglected.Although oral vancomycin is the first-line treatment for C. difficile associated diarrhoea, it will not limit patient to patient spread.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 120
Correct
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Which of the following microbes adheres to the genital mucosa using fimbriae:
Your Answer: Neisseria gonorrhoeae
Explanation:Infection of the genital mucosa by Neisseria gonorrhoeae involves attachment to and invasion of epithelial cells. Initial adherence of gonococci to columnar epithelial cells is mediated by type IV pili assembled from pilin subunit PilE proteins and pilus tip-associated PilC proteins, it then invades the epithelial layer, triggering a local acute inflammatory response.
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This question is part of the following fields:
- Microbiology
- Principles
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Question 121
Incorrect
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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: Atenolol
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.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 122
Correct
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You're called to a cardiac arrest in your Emergency Department resuscitation area. The rhythm strip is shown in the diagram below. Defibrillation has already been attempted three times on the patient. You intended to administer amiodarone, but your department has informed you that it is not available.In these circumstances, if amiodarone is not available, which of the following drugs is recommended by the ALS guidelines?
Your Answer: Lidocaine
Explanation:If amiodarone is unavailable in VF/pVT arrests, lidocaine at a dose of 1 mg/kg can be used instead, according to the latest ALS guidelines. If amiodarone has already been given, no lidocaine should be given.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 123
Correct
-
The following statements about leukotrienes as chemical mediators of the acute inflammatory response are all true EXCEPT?
Your Answer: They decrease vascular permeability
Explanation:Leukotrienes increases (not decrease) vascular permeability during acute inflammation.All the other statements are correct
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 124
Correct
-
All of the following statements is considered true regarding Streptococcus pneumoniae, except:
Your Answer: It is the commonest cause of erysipelas
Explanation:Erysipelas is a rare infection of the skin and subcutaneous tissues observed frequently in elderly patients. It is characterized by an acute spreading skin lesion that is intensely erythematous with a plainly demarcated but irregular edge. It is most commonly caused by Streptococcus pyogenes or Group A Streptococcus (GAS).GAS are susceptible to penicillin, which remains the drug of choice for treatment. For patients allergic to penicillin, erythromycin can be used.S. pyogenes colonizes the throat and skin on humans, making these sites the primary sources of transmission. Infections resulting from S. pyogenes include pharyngitis, scarlet fever, skin or pyodermal infections, and other septic infections. In addition, the sequelae rheumatic fever and acute glomerulonephritis can occur as a result of infection with S. pyogenes.Agammaglobulinemia is mostly associated with S. pneumoniae.The M protein is attached to the peptidoglycan of the cell wall and extends tothe cell surface. The M protein is essential for virulence. The polysaccharide capsule is characteristic of S. pneumoniae.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 125
Correct
-
A 39-year-old woman is feeling unwell one week after a parathyroid surgery.Which of the following stimulates release of parathyroid hormone (PTH)?
Your Answer: Increased plasma phosphate concentration
Explanation:PTH is synthesised and released from the chief cells of the four parathyroid glands located behind the thyroid gland.It is a polypeptide containing 84 amino acids and it controls free calcium in the body.The following stimuli causes release of PTH:Increased plasma phosphate concentrationDecreased plasma calcium concentrationPTH release is inhibited by:Normal or increased plasma calcium concentrationHypomagnesaemiaThe main actions of PTH are:Increases plasma calcium concentrationDecreases plasma phosphate concentrationIncreases osteoclastic activity (increasing calcium and phosphate resorption from bone)Increases renal tubular reabsorption of calciumDecreases renal phosphate reabsorptionIncreases renal conversion of 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol (via stimulation of 1-alpha hydroxylase)Increases calcium and phosphate absorption in the small intestine (indirectly via increased 1,25-dihydroxycholecalciferol)
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 126
Correct
-
Glomerular filtration rate can be calculated using any substance that:
Your Answer: is freely filtered and neither reabsorbed nor secreted by the nephron
Explanation:Clearance of a substance can provide an accurate estimate of the glomerular filtration rate (GFR) provided that the substance is:freely filterednot reabsorbed in the nephronnot secreted in the nephronnot synthesised or metabolised by the kidney
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This question is part of the following fields:
- Physiology
- Renal
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Question 127
Correct
-
Among the following microorganisms, which is considered to be transmitted by invasion of intact skin?
Your Answer: Leptospira spp.
Explanation:Rodents and domestic animals are the primary reservoirs for the Leptospira spp, although other animals, including cows, horses, mongooses, and frogs, can also harbour the leptospires. Humans may be directly infected from animal urine or indirectly by contact with soil or water that is contaminated with urine from infected animals. Infected humans can shed leptospires in urine for up to 11 months, infected cows for 3.5 months, infected dogs for 4 years, and infected rodents possibly for their entire lifetime.The organisms enter the host through mucous membranes or abraded skin. The incubation period ranges from 5 to 14 days.
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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Question 128
Incorrect
-
Tiredness, night sweats, and easy bruising are symptoms of a 58-year-old woman. Splenomegaly is observed during the examination.Which of the following diagnoses is the SINGLE MOST LIKELY?
Your Answer: Acute myeloid leukaemia (AML)
Correct Answer: Chronic myeloid leukaemia (CML)
Explanation:CML is a myeloproliferative disorder characterised by an abnormal pluripotent haemopoietic stem cell. A cytogenetic abnormality known as the Philadelphia chromosome, which results from a reciprocal translocation between the long arms of chromosomes 9 and 22, causes more than 80% of cases of CML.CML is a disease that develops slowly over several years. This is known as the ‘chronic stage.’ This stage is usually asymptomatic, and 90 percent of patients are diagnosed at this point, with the disease being discovered frequently as a result of a routine blood test. During this stage, the bone marrow contains less than 10% immature white cells (blasts).When CML cells expand, symptoms typically begin to appear. The ‘accelerated stage’ is what it’s called. Approximately 10% of people are diagnosed at this point. During this stage, between 10% and 30% of blood cells in the bone marrow are blasts. During this stage, common clinical features include:Fatigue and exhaustionNight sweats and feverDistension of the abdomenPain in the left upper quadrant (splenic infarction)Splenomegaly (commonest examination finding)HepatomegalyBruising is simple.Gout is a type of arthritis that affects (rapid cell turnover)Hyperviscosity is a condition in which the viscosity of (CVA, priapism)A small percentage of patients experience a ‘blast crisis’ (blast stage). More than 30% of the blood cells in the bone marrow are immature blast cells at this stage. Patients with severe constitutional symptoms (fever, weight loss, bone pain), infections, and bleeding diathesis typically present at this stage.In CML, laboratory findings include:White cell count is abnormally high (often greater than 100 x 109/l).Increased number of immature leukocytes causes a left shift.Anaemia that is mild to moderately normochromic and normocytic.Platelets can be low, normal, or elevated, and the Philadelphia chromosome can be found in > 80% of patients. Serum uric acid and ALP levels are frequently elevated. Tyrosine kinase inhibitors (TKIs), such as imatinib and dasatinib, are the current mainstay of CML treatment. Allogenic bone marrow transplantation is now only used in cases where TKIs have failed to work.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 129
Correct
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An 11-year-old presented to a GP with a history of headache, neck stiffness and photophobia. On examination, HR is 122, BP is 87/42, RR is 28, SaO 2 is 95%, temperature is 39.4 o C. There is a recent petechial rash on legs and arms. The GP administered a dose of antibiotics in the prehospital setting before transferring to the Emergency Department.Which of these would the GP have administered?
Your Answer: IM benzylpenicillin 1.2 g
Explanation:General Practitioners are advised to give a single injection of benzylpenicillin by intravenous or intramuscular injection before transferring the patient urgently to the ED when bacterial meningitis is suspected.The recommended doses are:Infants under 1 year: 300 mgChildren ages 1 to 9 years: 600 mgChildren aged 10 years and over: 1.2gAdults: 1.2g
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 130
Incorrect
-
What is the appropriate dose of 1:1000 adrenaline solution for a 15-year-old patient with suspected anaphylactic shock?
Your Answer: 0.5 grams intramuscularly
Correct Answer: 500 micrograms intramuscularly
Explanation:1: 1000 Adrenaline solution dosage for children above the age of 12 and adults, including pregnant women (over 50 kg) is 0.50 mL, which is equivalent to 500 mcg of adrenaline.
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 131
Correct
-
A patient suffers a lower limb fracture that causes damage to the nerve that innervates peroneus longus.Peroneus longus receives its innervation from which of the following nerves? Select ONE answer only.
Your Answer: Superficial peroneal nerve
Explanation:Peroneus brevis is innervated by the superficial peroneal nerve.Peroneus longus is innervated by the superficial peroneal nerve.Peroneus tertius is innervated by the deep peroneal nerve.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 132
Correct
-
Despite taking the oral contraceptive pill, a 29-year-old woman becomes pregnant. During a medication review, you discover that she is epileptic and that her antiepileptic therapy has recently been changed.Which of the following antiepileptics is most likely to impair the oral contraceptive pill's effectiveness?
Your Answer: Carbamazepine
Explanation:The metabolism of ethinyl oestradiol and progestogens has been shown to be increased by enzyme-inducing antiepileptics. The oral contraceptive pill (OCP) is less effective in preventing pregnancy as a result of this increased breakdown.Antiepileptic drugs that induce enzymes include:CarbamazepinePhenytoinPhenobarbitalTopiramateAntiepileptics that do not induce enzymes are unlikely to affect contraception. Non-enzyme-inducing anticonvulsants include the following:ClonazepamGabapentinLevetiracetamPiracetamSodium valproate is a type of valproate that is used toLamotrigine is an antiepileptic drug that does not cause the production of enzymes. It does, however, require special consideration, unlike other non-enzyme-inducing antiepileptics. The OCP does not appear to affect epilepsy directly, but it does appear to lower lamotrigine levels in the blood. This could result in a loss of seizure control and the occurrence of seizures.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 133
Correct
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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: Bilateral conjunctivitis
Explanation:Urgent referral to ophthalmology is indicated if the patient with conjunctivitis has any of the following:Suspected gonococcal or chlamydial conjunctivitisCorneal involvement associated with soft contact lens useSevere disease indicated by presence of a pseudomembraneConjunctivitis 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.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 134
Incorrect
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An 82 year old man taking warfarin as a maintenance medication comes in to your clinic because of an infection. Which antibiotic is the safest choice for this patient?
Your Answer: Co-trimodazole
Correct Answer: Cefalexin
Explanation:Alterations in the international normalized ratio (INR) brought about by the concurrent use of antibiotics and warfarin may result in either excessive clotting or excessive bleeding if they are deemed to have a high risk for interaction. As such, there should be careful consideration of the class of antibiotic to be used. Antibiotics from the following drug classes should generally be avoided as they have a high risk for interaction with warfarin, possible enhancing the anticoagulant effects of warfarin resulting in bleeding: Fluoroquinolones (e.g. ciprofloxacin, levofloxacin), Macrolides (e.g. clarithromycin, erythromycin, azithromycin), Nitroimidazoles (e.g. metronidazole), Sulphonamides (e.g. co-trimoxazole, a combination of trimethoprim and sulfamethoxazole), Trimethoprim, Tetracyclines (e.g. doxycycline). Low risk antibiotics that have low risk for interaction with warfarin includes cephalexin, from the cephalosporin class, and clindamycin which is a lincomycin.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 135
Correct
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After reviewing a child with respiratory distress who presented to the clinic, you make a diagnosis of bronchiolitis.What is the most common causative organism?
Your Answer: Respiratory syncitial virus
Explanation:Bronchiolitis is a common respiratory infection that occurs in infancy between the ages of 3-6 months and in the winter months. It is most commonly caused by the respiratory syncytial virus (70% of cases)Although it can also be caused by parainfluenza virus, adenovirus, coronavirus, rhinovirus, and influenza virus, these are not the most common causes
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 136
Incorrect
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A 68-year-old man with multiple myeloma presents with complaints of abdominal pain and malaise. A series of blood tests is done and his calcium level is 2.96 mmol/l.What effect will this blood test result have on gastric secretions?
Your Answer: Stimulate the release of gastric lipase
Correct Answer: Stimulate the release of gastrin
Explanation:Hypercalcaemia stimulates the release of gastrin from the G-cells in the pyloric antrum of the stomach, the duodenum and the pancreas.Gastrin is also released in response to:Stomach distensionVagal stimulationThe presence of amino acids.Gastrin release is inhibited by the presence of acid and somatostatin.
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This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 137
Incorrect
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A 66-year-old male is brought to your clinic by his wife with the complaint of increasing confusion and disorientation over the past three days, along with decreased urination. She reports that he has been complaining of increasing pain in his back and ribs over the past three months. On examination, the patient looks anaemic, is not oriented in time, place and person and has tenderness on palpation of the lumbar spine and the 10th, 11th and 12th ribs. Blood tests show anaemia which is normocytic, normochromic, raised urea and creatinine and hypercalcemia. Which one of the following diagnoses is most likely in this case?
Your Answer: Metastatic prostate cancer
Correct Answer: Multiple myeloma
Explanation:Multiple myeloma is a clonal abnormality affecting plasma cells in which there is an overproduction of functionless immunoglobulins. The most common patient complaint is bone pain, especially in the back and ribs. Anaemia and renal failure are common, along with hypercalcemia. Hypercalcemia may lead to an altered mental status, as in this case. Chronic lymphocytic leukaemia occurs due to the overproduction of lymphocytes, usually B cells. CLL may present with an asymptomatic elevation of B cells. Patients are generally more than 50 years old and present with non-specific fatigue and weight loss symptoms.There is no history of alcohol abuse in this case. Furthermore, patients with a history of alcohol abuse may have signs of liver failure, which are not present here. Metastatic prostate cancer would most often cause lower backache as it metastasises first to the lumbar spine via the vertebral venous plexus. A patient with Vitamin B12 deficiency would have anaemia, megaloblastic, hypersegmented neutrophils, and signs of peripheral neuropathy.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 138
Incorrect
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Which of the following statements is INCORRECT. Fick's law tells us that the rate of diffusion of a gas across a membrane increases as:
Your Answer: the membrane surface area increases.
Correct Answer: the partial pressure gradient decreases.
Explanation:Fick’s law tells us that the rate of diffusion of a gas increases: the larger the surface area involved in gas exchangethe greater the partial pressure gradient across the membranethe thinner the membranethe more soluble the gas in the membranethe lower the molecular weight of the gas
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 139
Incorrect
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Which of these statements about experimental studies is true?
Your Answer: Examples include cohort studies
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)
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This question is part of the following fields:
- Evidence Based Medicine
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Question 140
Incorrect
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Which of the following statements is correct regarding the partial pressure of oxygen during respiration?
Your Answer: Exhaled PO 2 < Alveolar PO 2 < Inhaled PO 2
Correct Answer: Exhaled PO 2 > Alveolar PO 2
Explanation:Because of humidification, inspired PO2 in the airways is less than inhaled PO2. Because of gas exchange, alveolar PO2 is less than inhaled or inspired PO2.Because of mixing with anatomical dead space (air that has not taken part in gas exchange, exhaled PO2 is greater than alveolar O2, and therefore that has relatively higher PO2 on the way out, but is less than inhaled or inspired PO2.Typical values for a resting young healthy male (in kPa) are shown below:-Inhaled air: PO221.2, PCO20.0-Inspired air in airways (after humidification): PO219.9, PCO20.0-Alveolar air (after equilibrium with pulmonary capillaries): PO213.3, PCO25.3-Exhaled air (after mixing with anatomical dead space air): PO215.5, PCO24.3
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 141
Correct
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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: 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.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 142
Correct
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A 20-year-old female presents with painful wrist following a fall while skating. X-rays shows fracture of the ulna.The initial phase of bone healing is?
Your Answer: Haematoma at the fracture site
Explanation:Haemorrhage occurs into the fracture site from the ruptured vessels in the bone marrow and those supplying the periosteum immediately after fracture. This hematoma formation is the first phase of bone healing.The 4 stages of bone healing are:Haematoma at the fracture site (provides a framework for healing)Callus formationLamellar bone formationRemodelling
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 143
Correct
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Mast cells play a significant part in which of the following?
Your Answer: Allergic disease
Explanation:Mast cells play a central role in the response to allergen challenges. The activation of mast cells results in both an early and a delayed phase of inflammation. Mast cells have been implicated in both physiologic and pathogenic processes. Mast cells are important in defence against some bacteria and viruses and contribute to defence against parasites. They are key effector cells in both innate and acquired immunity and are capable of inducing and amplifying both types of responses. Specifically, mast cells are capable of detecting microbial products through surface pattern recognition receptors, and they are involved in the recruitment of other leukocytes, containment of bacterial infections, and tissue repair.
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 144
Correct
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Fenestrated capillaries are typically found where in the body:
Your Answer: Renal glomeruli
Explanation:Fenestrated capillaries, found in renal glomeruli, endocrine glands and intestinal villi, are more permeable than continuous capillaries with less tight junctions, and the endothelial cells are also punctured by pores which allow large amounts of fluids or metabolites to pass.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 145
Correct
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You review a 46-year-old woman who has recently been prescribed antibiotics for a urinary tract infection. She suffers from COPD and is currently prescribed salbutamol and Seretide inhalers, and Phyllocontin continus. Since starting the antibiotics, she has been experiencing nausea, vomiting and abdominal pain.Which of the following antibiotics is she MOST LIKELY to have been prescribed for her UTI? Select ONE answer only .
Your Answer: Ciprofloxacin
Explanation:Phyllocontin continus contains aminophylline (a mixture of theophylline and ethylenediamine), a bronchodilator used in the management of COPD and asthma.This patient is exhibiting symptoms of theophylline toxicity, which may have been triggered by the prescription of the antibiotic. Quinolone antibiotics, such as ciprofloxacin and levofloxacin, and macrolide antibiotics, such as erythromycin, increase the plasma concentration of theophyllines and can lead to toxicity.The drugs that commonly affect the half-life and the plasma concentration of theophylline are summarised in the table below:Drugs increasing plasma concentration of theophyllineDrugs decreasing plasma concentration of theophyllineCalcium channel blockers, e.g. VerapamilCimetidineFluconazoleMacrolides, e.g. erythromycinQuinolones, e.g. ciprofloxacinMethotrexateBarbituratesCarbamazepinePhenobarbitolPhenytoin (and fosphenytoin)RifampicinSt. John’s wort
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This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 146
Correct
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A 33 year old lady with a known nut allergy was having dinner at a Thai restaurant. She suddenly complained of lip and tongue swelling and difficulty breathing and is brought to ED by ambulance with suspected anaphylaxis. She received intramuscular adrenaline in the ambulance.The most appropriate doses of the second line treatments for anaphylaxis are which of the following?
Your Answer: 10 mg chlorphenamine and 200 mg hydrocortisone
Explanation:Second line drugs to reduce the severity and duration of anaphylactic symptoms are intravenous or intramuscular chlorpheniramine and hydrocortisone. The recommended dose is 10 mg chlorpheniramine and 200 mg hydrocortisone in adults.
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 147
Correct
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All of the following are physiological effects of thyroid hormones except:
Your Answer: Increased glycogenesis
Explanation:Thyroid hormones have multiple physiological effects on the body. These include:1. Heat production (thermogenesis)2. Increased basal metabolic rate3. Metabolic effects: (a) Increase in protein turnover (both synthesis and degradation are increased, although overall effect is catabolic)(b) Increase in lipolysis(c)Increase in glycogenolysis and gluconeogenesis4. Enhanced catecholamine effect – Increase in heart rate, stroke volume and thus cardiac output5. Important role in growth and development
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 148
Incorrect
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Regarding the refractory period, which of the following statements is INCORRECT:
Your Answer: The absolute refractory period is due to the inactivation of Na + channels.
Correct Answer: Action potentials can occur in the relative refractory period but the amplitude of the action potential is smaller.
Explanation:Following the action potential, Na+channels remain inactive for a time in a period known as the absolute refractory period where they cannot be opened by any amount of depolarisation. Following this there is a relative refractory period where the temporary hyperpolarisation (due to delayed closure of rectifier K+channels) makes the cell more difficult to depolarise and an action potential can be generated only in response to a larger than normal stimulus. The refractory period limits the frequency at which action potentials can be generated, and ensures that, once initiated, an action potential can travel only in one direction. An action potential is an all or nothing response so the amplitude of the action potential cannot be smaller.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 149
Correct
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A 28-year-old female arrives after taking an unknown chemical in excess. She is tired and her speech is slurred. The following are her observations and results: HR 118, BP 92/58, SaO2 96%HR 118, 11/15  The following are the results of his arterial blood gas (ABG):pH: 7.24 pO 2 : 9.4 kPa PCO2 : 3.3 kPa HCO 3 -: 22 mmol/l Na + : 143 mmol/l Cl – : 99 mmol/l Lactate: 5 IU/lWhich of the following statements about this patient is TRUE?
Your Answer: Her anion gap is elevated
Explanation:The interpretation of arterial blood gas (ABG) aids in the measurement of a patient’s pulmonary gas exchange and acid-base balance. The normal values on an ABG vary a little depending on the analyser, but they are roughly as follows:Variable RangepH 7.35 – 7.45PaO2 10 – 14 kPaPaCO2 4.5 – 6 kPaHCO3- 22 – 26 mmol/lBase excess -2 – 2 mmol/lThe patient’s history indicates that she has taken an overdose in this case. Because her GCS is 11/15 and she can communicate with slurred speech, she is clearly managing her own airway, there is no current justification for intubation.The following are the relevant ABG findings:Hypoxia (mild)pH has been lowered (acidaemia)PCO2 levels are low.bicarbonate in its natural stateLactate levels have increasedThe anion gap represents the concentration of all the unmeasured anions in the plasma. It is the difference between the primary measured cations and the primary measured anions in the serum. It can be calculated using the following formula:Anion gap = [Na+] – [Cl-] – [HCO3-]The reference range varies depending on the technique of measurement, but it is usually between 8 and 16 mmol/L.The following formula can be used to compute her anion gap:Anion gap = [143] – [99] – [22]Anion gap = 22As a result, it is clear that she has a metabolic acidosis with an increased anion gap.The following are some of the causes of type A and type B lactic acidosis:Type A lactic acidosisType B lactic acidosisShock (including septic shock)Left ventricular failureSevere anaemiaAsphyxiaCardiac arrestCO poisoningRespiratory failureSevere asthma and COPDRegional hypoperfusionRenal failureLiver failureSepsis (non-hypoxic sepsis)Thiamine deficiencyAlcoholic ketoacidosisDiabetic ketoacidosisCyanide poisoningMethanol poisoningBiguanide poisoning
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 150
Correct
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Which of the following is the site of secretion of intrinsic factor:
Your 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.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 151
Correct
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Which coronary artery is mostly likely affected if an ECG shows a tombstone pattern in leads V2, V3 and V4?
Your Answer: Left anterior descending artery
Explanation:Tombstoning ST elevation myocardial infarction can be described as a STEMI characterized by tombstoning ST-segment elevation. This myocardial infarction is associated with extensive myocardial damage, reduced left ventricle function, serious hospital complications and poor prognosis. Tombstoning ECG pattern is a notion beyond morphological difference and is associated with more serious clinical results.Studies have shown that tombstoning is more commonly found in anterior than non-anterior STEMI, thus, higher rates of left anterior descending artery disease are observed in patients with tombstoning pattern.The following ECG leads determine the location and vessels involved in myocardial infarction:ECG Leads Location Vessel involvedV1-V2 Septal wall Left anterior descendingV3-V4 Anterior wall Left anterior descendingV5-V6 Lateral wall Left circumflex arteryII, III, aVF Inferior wall Right coronary artery (80%) or Left circumflex artery (20%)I, aVL High lateral wall Left circumflex arteryV1, V4R Right ventricle Right coronary arteryV7-V9 Posterior wall Right coronary artery
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 152
Correct
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All of the following statements are correct regarding penicillin antibiotics except:
Your Answer: Penicillins are of no use in meningitis as they are unable to penetrate into the cerebrospinal fluid.
Explanation:Penicillin penetration into the cerebrospinal fluid is generally poor. However, when the meninges are inflamed, as in meningitis, penetration of penicillin is increased. Benzylpenicillin should be given before transfer to hospital if meningococcal disease (meningitis with non-blanching rash or meningococcal septicaemia) is suspected, once this does not delay transfer. Benzylpenicillin is no longer the drug of first choice for pneumococcal meningitis.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 153
Incorrect
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If the afferent arteriole's diameter is smaller than the efferent arteriole's diameter in the glomerulus:
Your Answer: The glomerular filtration rate will increase
Correct Answer: The net filtration pressure will decrease
Explanation:The relative resistance of the afferent and efferent arterioles substantially influences glomerular capillary hydrostatic pressure and consequently GFR. Filtration is forced through the filtration barrier due to high pressure in the glomerular capillaries. Afferent arteriolar constriction lowers this pressure while efferent arteriolar constriction raises it.
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This question is part of the following fields:
- Physiology
- Renal
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Question 154
Correct
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Which of the following statements is considered correct regarding Klebsiella infections?
Your Answer: Klebsiella spp. are non-motile
Explanation:Klebsiella is a Gram-negative, rod-shaped, non-motile bacteria. The absence of motility distinguishes Klebsiella spp. from most other members of the family Enterobacteriaceae. K. pneumoniae is the most commonly isolated species and has the distinct feature of possessing a large polysaccharide capsule. The capsule offers the organism protection against phagocytosis and antimicrobial absorption,contributing to its virulence. Colonization of gram-negative bacilli in the respiratory tracts of hospitalized patients, particularly by K. pneumoniae, increases with the length of hospital stay. It is a frequent cause of lower respiratory tract infections among hospitalized patients and in immunocompromised hosts such as newborns,elderly patients, and seriously ill patients on respirators.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 155
Correct
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You are taking care of a 55-year-old male patient with a direct inguinal hernia. In explaining his hernia, which of the following layers was compromised and had resulted in his condition?
Your Answer: Transversalis fascia
Explanation:Direct inguinal hernias are most often caused by a weakness in the muscles of the abdominal wall that develops over time, or are due to straining or heavy lifting. A direct inguinal hernia protrudes through the Transversalis fascia.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 156
Incorrect
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A patient is diagnosed as having a glucagonoma. Her blood serum glucagon concentration is 1246 pg/mL.Glucagon INHIBITS which of the following processes? Select ONE answer only.
Your Answer: The hydrolysis of triglycerides
Correct Answer: Glycolysis
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:GlycogenolysisGluconeogenesisLipolysis in adipose tissueThe secretion of glucagon is also stimulated by:AdrenalineCholecystokininArginineAlanineAcetylcholineThe secretion of glucagon is inhibited by:InsulinSomatostatinIncreased free fatty acidsIncreased urea productionGlycolysis is the metabolic pathway that converts glucose into pyruvate. The free energy released by this process is used to form ATP and NADH. Glycolysis is inhibited by glucagon, and glycolysis and gluconeogenesis are reciprocally regulated so that when one cell pathway is activated, the other is inactive and vice versa.Glucagon has a minor effect of enhancing lipolysis in adipose tissue. Lipolysis is the breakdown of lipids and involves the hydrolysis of triglycerides into glycerol and free fatty acids. It makes fatty acids available for oxidation.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 157
Correct
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A dermatological examination of a patient presenting with a lump shows a visible collection of fluid measuring 0.3 cm in diameter.Which one of these best describes the lump you have found on examination?
Your Answer: Vesicle
Explanation:A vesicle is a visible collection of fluid measuring less than 0.5 cm in diameter.A furuncle, or boil, is a pyogenic infection of the hair follicle commonly caused by infection with Staphylococcus aureus. A carbuncle is a collection of individual boils clustered together. A bulla is a visible collection of clear fluid measuring greater than 0.5 cm in diameter. A pustule is a small visible skin elevation containing an accumulation of pus.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 158
Correct
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Cystic fibrosis patients have a weakened lung surfactant system. Which of the following cell types is in charge of surfactant secretion?
Your Answer: Type II pneumocytes
Explanation:Alveolar type II cells are responsible for four primary functions: surfactant synthesis and secretion, xenobiotic metabolism, water transepithelial transport, and alveolar epithelium regeneration following lung injury.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 159
Incorrect
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An 80-year-old female complains of chest pain characteristic of angina. A dose of glyceryl trinitrate (GTN) is administered that resolves the chest pain rapidly. Which ONE of the following is released on the initial metabolism of GTN?
Your Answer: Nitric oxide
Correct Answer: Nitrite ions
Explanation:Angina pectoris is the most common symptom of ischemic heart disease and presents with chest pain relieved by rest and nitro-glycerine. Nitrates are the first-line treatment to relieve chest pain caused by angina. The commonly used nitrates are: 1. Glyceryl trinitrate 2. Isosorbide dinitrate The nitrate drugs are metabolized in the following steps: 1. Release Nitrite ions (NO2-), which are then converted to nitric oxide (NO) within cells. 2. NO activates guanylyl cyclase, which causes an increase in the intracellular concentration of cyclic guanosine-monophosphate (cGMP) in vascular smooth muscle cells. 3. Relaxation of vascular smooth muscle.Although nitrates are potent coronary vasodilators, their principal benefit in the management of angina results from a predominant mechanism of venous dilation:- Bigger veins hold more blood- Takes blood away from the left ventricle- Lowers LVEDV (preload), LA pressure- Less pulmonary oedema → improved dyspnoea
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 160
Correct
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When calculating the ventilation over perfusion ratio of a male patient, you should remember the ideal V/Q ratio for this patient to compare with his results. What is the approximate ventilation value for a healthy male patient?
Your Answer: 5 L/min
Explanation:The ventilation/perfusion ratio (V/Q ratio) is a ratio used to assess the efficiency and adequacy of the matching ventilation and perfusion. The ideal V/Q ratio is 1. In an average healthy male, the ventilation value is approximately 5 L/min and the perfusion value is approximately 5 L/min. Any mismatch between ventilation and perfusion will be evident in the V/Q ratio. If perfusion is normal but ventilation is reduced, the V/Q ratio will be less than 1, whereas if ventilation is normal but perfusion is reduced, the V/Q ratio will be greater than 1. If the alveoli were ventilated but not perfused at all, then the V/Q ratio would be infinity.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 161
Correct
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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.At the moment, he is completely symptom-free. When it comes to this type of overdose, how long does it usually take for symptoms to appear?
Your Answer: 1-2 hours
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.>10 tablets of verapamil (160 mg or 240 mg immediate or sustained-release capsules) or diltiazem can cause serious toxicity (180 mg, 240 mg or 360 mg immediate or sustained-release capsules)In children, 1-2 tablets of verapamil or diltiazem (immediate or sustained-release)Symptoms usually appear within 1-2 hours of ingestion with standard preparations. However, with slow-release preparations, significant toxicity may take 12-16 hours to manifest, with peak effects occurring after 24 hours.The following are the main clinical features of calcium-channel blocker overdose:Nausea and vomitingHypotensionBradycardia and first-degree heart blockMyocardial ischaemia and strokeRenal failurePulmonary oedemaHyperglycaemiaThe following are some of the most important bedside investigations to conduct:Blood glucoseECGArterial blood gasOther investigations that can be helpful includeUrea & electrolytesChest X-ray (pulmonary oedema)Echocardiography
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 162
Correct
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Question 163
Incorrect
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Gastrin release from antral G-cells is inhibited by all but which one of the following:
Your Answer: Low gastric pH
Correct Answer: Vagal stimulation
Explanation:Gastrin secretion is inhibited by:Low gastric pH (negative feedback mechanism)SomatostatinSecretinGastric inhibitory polypeptide (GIP)Cholecystokinin
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 164
Correct
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A 7-days-old neonate is taken to the emergency department. She's pyretic, lethargic, and unresponsive, and her fontanelle has bulged. Antibiotics are started, and a lumbar puncture reveals Gram-negative rods. Which pathogen is most likely to be the cause:
Your Answer: Escherichia coli
Explanation:Among neonates, group B streptococci (GBS) are the most commonly identified causes of bacterial meningitis, implicated in roughly 50% of all cases. Escherichia coli(Gram-negative rods) accounts for another 20%. Thus, the identification and treatment of maternal genitourinary infections is an important prevention strategy.
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This question is part of the following fields:
- Infections
- Microbiology
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Question 165
Correct
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A 25-year old male is brought to the emergency room after a traffic accident. Upon examination, there was tenderness and erythema on the right acromioclavicular joint, with notable step deformity. On radiographic imaging, there is a superior elevation of the clavicle, a twice than normal coracoclavicular distance, and absence of fracture.Which of the following structure/s is/are likely to have ruptured?
Your Answer: Acromioclavicular ligament, coracoclavicular ligament and joint capsule
Explanation:Acromioclavicular joint injuries account for more than forty percent of all shoulder injuries. Mild injuries are not associated with any significant morbidity, but severe injuries can lead to significant loss of strength and function of the shoulder. Acromioclavicular injuries may be associated with a fractured clavicle, impingement syndromes, and more rarely neurovascular insults.The AC joint is a diarthrodial joint defined by the lateral process of the clavicle articulating with the acromion process as it projects anteriorly off the scapula. The joint is primarily stabilized by the acromioclavicular ligament, which is composed of an anterior, posterior, inferior, and superior component. Of note, the superior portion of the AC ligament is the most important component for the stability of the AC joint. Supporting structures include two coracoclavicular ligaments (trapezoid and conoid ligaments), which provide vertical stability, as well as the coracoacromial ligament.Patients with an AC joint injury typically present with anterosuperior shoulder pain and will describe a mechanism of injury of blunt trauma to the abducted shoulder or landing on an outstretched arm, suggestive of this type of injury. They may describe pain radiating to the neck or shoulder, which is often worse with movement or when they try to sleep on the affected shoulder. On examination, the clinician may observe swelling, bruising, or a deformity of the AC joint, depending on the degree of injury. The patient will be tender at that location. They may have a restriction in the active and passive range of motion secondary to pain. Piano key sign may be seen, with an elevation of the clavicle that rebounds after inferior compression.Standard X-rays are adequate to make a diagnosis of acromioclavicular joint injury and should be used to evaluate for other causes of traumatic shoulder pain.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 166
Correct
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You plan to use plain 1% lidocaine for a ring block on a finger that needs suturing.Which SINGLE statement regarding the use of 1% lidocaine, in this case, is true?
Your Answer: Lidocaine works by blocking fast voltage-gated sodium channels
Explanation:Lidocaine is a tertiary amine that is primarily used as a local anaesthetic but can also be used intravenously in the treatment of ventricular dysrhythmias.Lidocaine works as a local anaesthetic by diffusing in its uncharged base form through neural sheaths and the axonal membrane to the internal surface of the cell membrane sodium channels. Here it alters signal conduction by blocking the fast voltage-gated sodium channels. With sufficient blockage, the membrane of the postsynaptic neuron will not depolarise and will be unable to transmit an action potential, thereby preventing the transmission of pain signals.Each 1 ml of plain 1% lidocaine solution contains 10 mg of lidocaine hydrochloride. The maximum safe dose of plain lidocaine is 3 mg/kg. When administered with adrenaline 1:200,000, the maximum safe dose is 7 mg/kg. Because of the risk of vasoconstriction and tissue necrosis, lidocaine should not be used in combination with adrenaline in extremities such as fingers, toes, and the nose.The half-life of lidocaine is 1.5-2 hours. Its onset of action is rapid within a few minutes, and it has a duration of action of 30-60 minutes when used alone. Its duration of action is prolonged by co-administration with adrenaline (about 90 minutes).Lidocaine tends to cause vasodilatation when used locally. This is believed to be due mainly to the inhibition of action potentials via sodium channel blocking in vasoconstrictor sympathetic nerves.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 167
Correct
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What type of visual field defect are you most likely to see in a lesion of the parietal optic radiation:
Your Answer: Contralateral homonymous inferior quadrantanopia
Explanation:A lesion of the parietal optic radiation will result in a contralateral homonymous inferior quadrantanopia.A lesion of the temporal optic radiation will result in a contralateral homonymous superior quadrantanopia.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 168
Correct
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You have been called to review a patient and his management in the resuscitation room. A very sick patient has been started on mannitol in his treatment protocol. Out of the following, what is NOT an FDA-recognized indication for the use of mannitol?
Your Answer: Congestive cardiac failure
Explanation:Mannitol is the most widely used osmotic diuretic that is most commonly used to reduce cerebral oedema and intracranial pressure. Mannitol has four FDA approved uses clinically:1. Reduction of intracranial pressure and brain mass2. reduce intraocular pressure if this is not achievable by other means3. promote diuresis for acute renal failure to prevent or treat the oliguric phase before irreversible damage4. promote diuresis to promote the excretion of toxic substances, materials, and metabolitesIt can be used in rhabdomyolysis-induced renal failure, especially in crush injuries. Mannitol reduces osmotic swelling and oedema in the injured muscle cells and helps restore skeletal muscle function. It is a low molecular weight compound and can be freely filtered at the glomerulus and not reabsorbed. This way increases the osmolality of the glomerular filtrate and tubular fluid, increasing urinary volume by an osmotic effect. It also does not cross the blood-brain barrier (BBB).Mannitol causes an expansion of the extracellular fluid space, which may worsen congestive cardiac failure. Contraindications to the use of mannitol include:1. Anuria due to renal disease2. Acute intracranial bleeding (except during craniotomy)3. Severe cardiac failure4. Severe dehydration5. Severe pulmonary oedema or congestion6. Known hypersensitivity to mannitol
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 169
Correct
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A 4-year-old child has been convulsing for 20 minutes. She has received two doses of lorazepam. She takes phenytoin for maintenance therapy, and you draw up a phenobarbitone infusion.What dose of phenobarbitone is advised in the treatment of the convulsing child that reaches that stage of the APLS algorithm? Select ONE answer only.
Your Answer: 20 mg/kg over 30-60 minutes
Explanation:If a convulsing child reaches step 3 of the APLS algorithm, then a phenytoin infusion should be set up at 20 mg/kg over 20 minutes. If they are already taken phenytoin as maintenance therapy, then a phenobarbitone infusion should be set up at 20 mg/kg over 30-60 minutes.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 170
Correct
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A patient with profuse watery diarrhoea was found to have C. difficile cytotoxin. Which of the following complications is NOT a typical complication of pseudomembranous colitis:
Your Answer: Volvulus
Explanation:Dehydration, electrolyte imbalance, acute kidney injury secondary to diarrhoea, toxic megacolon, bowel perforation, and sepsis secondary to intestinal infection are all possible complications of pseudomembranous colitis. When the intestine twists around itself and the mesentery that supports it, an obstruction is created. This condition is known as a volvulus. Volvulus is caused by malrotation and other anatomical factors, as well as postoperative abdominal adhesions, and not by Clostridium difficile infection.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 171
Correct
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Which of the following is a physiological function that is mediated by a hormone released by the posterior pituitary:
Your Answer: Water retention
Explanation:Antidiuretic hormone (ADH), released by the posterior pituitary, acts on the kidneys to increase water permeability in the distal nephron allowing greater water reabsorption and concentration of urine. Prolactin, from the anterior pituitary, is responsible for milk production. The thyroid hormones, from the thyroid gland, are responsible for an increase in basal metabolic rate (stimulated by TSH from the anterior pituitary). FSH/LH, from the anterior pituitary, are responsible for maturation of egg and sperm. Calcitonin, from the thyroid gland, is responsible for decreasing calcium levels.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 172
Correct
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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: The platelet count should be checked 2-4 hours after starting treatment
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 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 yearsIntracranial tumour
Aneurysm or arteriovenous malformation
Haemorrhagic diathesis
Vasculitis
Retinopathy caused by hypertension
The 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
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 173
Incorrect
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Elevation of the mandible is produced primarily by which of the following muscles:
Your Answer: Temporalis, masseter and lateral pterygoid
Correct Answer: Temporalis, masseter and medial pterygoid
Explanation:Elevation of the mandible is generated by the temporalis, masseter and medial pterygoid muscles.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 174
Incorrect
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All of the following statements are incorrect about insulin except:
Your Answer: Insulin is secreted from pancreatic alpha cells.
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.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 175
Incorrect
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A 40-year-old woman presents with a red, scaly, itchy rash around her navel that occurred after contact with a nickel belt buckle. A diagnosis of allergic contact dermatitis is made. Which type of hypersensitivity reaction is this?
Your Answer: Type III hypersensitivity reaction
Correct Answer: Type IV hypersensitivity reaction
Explanation:A type IV hypersensitivity reaction occurred in this patient. Allergic contact dermatitis is an inflammatory skin reaction occurring in response to an external stimulus, acting either as an allergen or an irritant, caused by a type IV or delayed hypersensitivity reaction. They usually take several days to develop.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 176
Incorrect
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All of the following statements are considered true regarding likelihood ratios, except:
Your Answer: The likelihood ratio for a negative test = (1-sensitivity) / specificity
Correct Answer: If less than one, indicates that the information increases the likelihood of the suspected diagnosis
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.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 177
Correct
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Which of the following is a contraindication for aspirin?
Your Answer: Children under 16 years
Explanation:Aspirin contraindications include: hypersensitivity to NSAIDs; asthma, rhinitis, and nasal polyps; and usage in children or teens.There is little evidence of allergic cross-reactivity for salicylates. However, due to similarities in chemical structure and/or pharmacologic activities, the possibility of cross-sensitivity cannot be completely ruled out.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 178
Correct
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Question 179
Correct
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Regarding antimuscarinic antispasmodics, which of the following statements is CORRECT:
Your Answer: They are contraindicated in paralytic ileus.
Explanation:Antimuscarinics are contraindicated in paralytic ileus. Antimuscarinics reduce intestinal motility by blocking muscarinic acetylcholine receptors and relaxing smooth muscle. Hyoscine butylbromide is advocated as a gastrointestinal antispasmodic, but it is poorly absorbed and thus has limited clinical utility. Antimuscarinics cause a reduction in bronchial secretions (they can be used to this effect in palliative patients). Antispasmodics are occasionally of value in treating abdominal cramp associated with diarrhoea but they should not be used for primary treatment. Antispasmodics should be avoided in young children with gastroenteritis because they are rarely effective and have troublesome side effects.
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This question is part of the following fields:
- Gastrointestinal
- Pharmacology
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Question 180
Correct
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Regarding chronic idiopathic thrombocytopaenic purpura (ITP), which of the following statements is INCORRECT:
Your Answer: ITP is classically associated with massive splenomegaly.
Explanation:Chronic ITP is a relatively common disorder. The highest incidence is in women aged 15 – 50 years. It is the most common cause of thrombocytopaenia without anaemia or neutropaenia. It is usually idiopathic but it may been seen in association with other conditions. Platelet autoantibodies (usually IgG) result in the premature removal of platelets from the circulation by macrophages of the reticuloendothelial system. In many causes the antibody is directed against the glycoprotein IIb/IIIa or Ib complex. The normal platelet lifespan of 10 days is reduced to a few hours. Total megakaryocyte mass and platelet turnover are increased to approximately five times normal. Despite the destruction of platelets by splenic macrophages, the spleen is normally not enlarged. In fact, an enlarged spleen should lead to a search for other possible causes for the thrombocytopenia.
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This question is part of the following fields:
- Haematology
- Pathology
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SESSION STATS - PERFORMANCE PER SPECIALTY
