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Question 1
Correct
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A 43-year old male is taken to the Emergency Room for a lacerated wound on the abdomen, situated above the umbilicus. A short segment of the small bowel has herniated through the wound.
Which of these anatomic structures is the deepest structure injured in the case above?Your Answer: Transversalis fascia
Explanation:The following structures are the layers of the anterior abdominal wall from the most superficial to the deepest layer:
Skin
Fatty layer of the superficial fascia (Camper’s fascia)
Membranous layer of the superficial fascia (Scarpa’s fascia)
Aponeurosis of the external and internal oblique muscles
Rectus abdominis muscle
Aponeurosis of the internal oblique and transversus abdominis
Fascia transversalis
Extraperitoneal fat
Parietal peritoneum -
This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 2
Incorrect
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Regarding apoptosis, which of the following statements is INCORRECT:
Your Answer: Apoptosis is mediated by activation of a caspase cascade.
Correct Answer: Apoptosis leads to cell swelling and eventual cell lysis.
Explanation:Apoptosis is a controlled form of cell death in which no cellular contents are released from the dying cell, and thus no inflammatory reaction is seen. Apoptosis may occur physiologically or pathologically. Apoptosis may be induced in two main ways: by the engagement of surface death receptors e.g. TNF-alpha (extrinsic pathway) or through cellular injury (intrinsic pathway). The end result is the activation of proteases enzymes called caspases which dismantle the cell cytoplasm and nucleus. Apoptotic cells shrink down and fragment into apoptotic bodies, each of which retains an intact cell membrane; apoptotic bodies are then targeted or rapid removal by adjacent cells. Disordered apoptosis is thought to be central to a number of important disease processes, particularly carcinogenesis.
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This question is part of the following fields:
- Inflammatory Responses
- Pathology
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Question 3
Correct
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You are going to prescribe a NSAID to a 50-year-old male patient for his back pain. Which of the following NSAIDs is least likely to cause gastrointestinal side effects:
Your Answer: Ibuprofen
Explanation:NSAIDs are associated with serious gastrointestinal irritation and drug-induced ulcers.
Among the NSAIDs included in the choices, ibuprofen has the lowest risk.
Piroxicam, ketoprofen, and ketorolac trometamol are associated with the highest risk of serious upper gastrointestinal side effects.
Indomethacin, diclofenac, and naproxen are associated with an intermediate risk of serious upper gastrointestinal side effects.
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This question is part of the following fields:
- Musculoskeletal
- Pharmacology
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Question 4
Correct
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A man suffered from a back injury due to a fall from a ladder. Significant bruising was found to be overlying his latissimus dorsi muscle.
Which of the following statements regarding the latissimus dorsi muscle is considered correct?Your Answer: It raises the body towards the arm during climbing
Explanation:The latissimus dorsi muscle is a broad, flat muscle that occupies the majority of the lower posterior thorax. The muscle’s primary function is of the upper extremity but is also considered to be a respiratory accessory muscle.
Latissimus dorsi is a climbing muscle. With the arms fixed above the head, it can raise the trunk upwards, together with the help of pectoralis major.
Functionally, the latissimus dorsi muscle belongs to the muscles of the scapular motion. This muscle is able to pull the inferior angle of the scapula in various directions, producing movements on the shoulder joint (internal rotation, adduction and extension of the arm). It is innervated by the thoracodorsal nerve (C6 – C8) from the posterior cord of the brachial plexus, which enters the muscle on its deep surface.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 5
Correct
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Which of the following drugs is first line treatment for a stable regular broad-complex tachycardia:
Your Answer: Amiodarone
Explanation:A regular broad-complex tachycardia is likely to be ventricular tachycardia or a regular supraventricular rhythm with bundle branch block. A ventricular tachycardia (or broad-complex tachycardia of uncertain origin) should be treated with amiodarone 300 mg IV over 10 – 60 min, followed by an infusion of 900 mg over the next 24 hours. If previously confirmed as SVT with bundle branch block, the patient should be treated as for narrow-complex tachycardia.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 6
Incorrect
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Regarding the cardiac cycle, which of the following statements is INCORRECT:
Your Answer: The length of diastole decreases with increasing heart rate.
Correct Answer: The second heart sound occurs in late diastole caused by closure of the atrioventricular valves.
Explanation:Diastole is usually twice the length of systole at rest, but decreases with increased heart rate. During systole, contraction of the ventricles compresses the coronary arteries and suppresses blood flow. This is particularly evident in the left ventricle, where during systole the ventricular pressure is the same as or greater than that in the arteries and as a result more than 85% of left ventricular perfusion occurs during diastole. This becomes a problem if the heart rate is increased as the diastolic interval is shorter and can result in ischaemia. The second heart sound, caused by closure of the semilunar valves, marks the end of systole.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 7
Correct
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In the emergency room, a 28-year-old woman complains of wobbly and slurred speech, is unable to do the heel-shin test, and has nystagmus. The following signs are most likely related to damage to which of the following areas:
Your Answer: Cerebellum
Explanation:Cerebellar injury causes delayed and disorganized motions. When walking, people with cerebellar abnormalities sway and stagger.
Damage to the cerebellum can cause asynergia, the inability to judge distance and when to stop, dysmetria, the inability to perform rapid alternating movements or adiadochokinesia, movement tremors, staggering, wide-based walking or ataxic gait, a proclivity to fall, weak muscles or hypotonia, slurred speech or ataxic dysarthria, and abnormal eye movements or nystagmus.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 8
Correct
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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 can be typed using a RFLP method
Explanation:Although a variety of clinical specimens may be submitted to the
laboratory to recover MTB and NTM, respiratory secretions such
as sputum and bronchial aspirates are the most common. An
early-morning specimen should be collected on three consecutive
days, although recent studies have suggested that the addition of
a third specimen does not significantly increase the sensitivity
of 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 complex
bacilli directly from patient specimens can be performed in as little as 6 to 8 hours on processed specimens. -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 9
Correct
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A GP is considering prescribing a non-steroidal anti-inflammatory (NSAID) for pain relief for a patient with a knee injury
Which of these statements about NSAIDs is NOT true?Your Answer: Side effects are less commonly seen with indomethacin than naproxen
Explanation:Most NSAIDs act as non-selective inhibitors of the enzyme cyclo-oxygenase (COX). They inhibit both COX-1 and COX-2 isoenzymes.
Only about 60% of patients will respond to any given NSAID.
It can take 21 days of treatment for a clinically appreciable reduction in inflammation to be apparent. If no improvement is seen after 21 days, the NSAID should be changed.
The use of NSAIDs in the 3rd trimester of pregnancy is associated with the following risks: delayed onset of labour, premature closure of ductus arteriosus and foetal kernicterus.
Side effects are lowest in Ibuprofen and highest in indomethacin. so side effects are more commonly seen with indomethacin than naproxen.
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This question is part of the following fields:
- Musculoskeletal Pharmacology
- Pharmacology
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Question 10
Correct
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After collapsing in his nursing home, a 70-year-old man is brought into the ER. He has diabetes mellitus and is on medication for it. An RBS of 2.0 mmol/L (3.9-5.5 mmol/L) is recorded in the ER.
Out of the following, which medication for diabetes mellitus is LEAST likely responsible for his hypoglycaemic episode?Your Answer: Metformin
Explanation:Metformin is a biguanide used as the first-line to treat type 2 diabetes mellitus. It has a good reputation as it has an extremely low risk of causing hypoglycaemia compared to the other agents for diabetes. It does not affect the insulin secreted by the pancreas or increase insulin levels. Toxicity with metformin can, however, cause lactic acidosis with associated hypoglycaemia.
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This question is part of the following fields:
- Endocrine Pharmacology
- Pharmacology
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Question 11
Correct
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Which of the following is NOT one of the cardinal features of acute inflammation:
Your Answer: Discharge
Explanation:Classic signs:
Rubor (redness)
Calor (heat)
Dolour (pain)
Tumour (swelling)
Functio laesa (loss of function)
These classic signs are produced by a rapid vascular response and cellular events. The main function of these events is to bring elements of the immune system to the site of injury and prevent further tissue damage. -
This question is part of the following fields:
- Inflammatory Responses
- Pathology
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Question 12
Correct
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A 64-year-old woman had a humerus midshaft fracture due to tripping on a curb and falling on her left arm. She might also have damaged which of the following structures?
Your Answer: Radial nerve and deep brachial artery
Explanation:The radial nerve and brachial artery are most likely to be damaged in humerus fractures. They are tethered together to the bone and cannot withstand the forces applied to it as a result of the displacement.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 13
Incorrect
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A 70-year old male is taken to the Emergency Room after suffering a traumatic fall while showering. Upon physical examination, the attending physician noted a hyperextended neck, 1/5 muscle strength in both upper extremities, 4/5 muscle strength in both lower extremities, and variable loss in sensation. The patient is placed in the wards for monitoring. For the next 24 hours, anuria is noted.
Which of the following spinal cord injuries is the most likely diagnosis?Your Answer: Anterior cord syndrome
Correct Answer: Central cord syndrome
Explanation:Central cord syndrome is the most common type of incomplete cord injury and almost always occurs due to a traumatic injury. It results in motor deficits that are worse in the upper extremities as compared to the lower extremities. It may also cause bladder dysfunction (retention) and variable sensory deficits below the level of injury.
The majority of these patients will be older and present with symptoms after a fall with hyperextension of their neck. On examination, patients will have more significant strength impairments in the upper extremities (especially the hands) compared to the lower extremities. Patients often complain of sensory deficits below the level of injury, but this is variable. Pain and temperature sensations are typically affected, but the sensation of light touch can also be impaired. The most common sensory deficits are in a cape-like distribution across their upper back and down their posterior upper extremities. They will often have neck pain at the site of spinal cord impingement.
Bladder dysfunction (most commonly urinary retention) and priapism can also be signs of upper motor neuron dysfunction. The sacral sensation is usually preserved, but the clinician should assess the rectal tone to evaluate the severity of the compression.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 14
Incorrect
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An 80-year-old patient with a history of chronic heart failure presents to you. Examination reveals widespread oedema.
Which statement about plasma oncotic pressure (Ï€ p ) is true?Your Answer: The osmotic effect of albumin is decreased by the Gibbs-Donnan effect
Correct Answer: The influence of π p on fluid movement is negligible if the capillary reflection co-efficient is 0.1
Explanation:Plasma oncotic pressure (Ï€p) is typically 25-30 mmHg.
70% of π p is generated by albumin so Hypoalbuminemia will decrease π p
The osmotic power of albumin is enhanced by the Gibbs-Donnan effect.
The influence of π p on fluid movement is negligible if the capillary reflection coefficient is 0.1. Another way of saying a vessel is highly permeable is saying the reflection coefficient is close to 0.
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This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
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Question 15
Correct
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Which one these is an example of a cause of an exudate?
Your Answer: Subphrenic abscess
Explanation:An exudate is an inflammatory fluid emanating from the intravascular space due to changes in the permeability of the surrounding microcirculation.
Some common causes of exudates are: pneumonia, empyema, lung cancer, breast cancer, cancer of the pleura, SLE, rheumatoid arthritis, pericarditis, subphrenic abscess, chylothorax.
Myxoedema, nephrotic syndrome, congestive cardiac failure, and liver cirrhosis all cause TRANSUDATE.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 16
Correct
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Which of the following clinical features is most suggestive of a lesion of the occipital lobe:
Your Answer: Homonymous hemianopia
Explanation:Homonymous hemianopia is a visual field defect involving either the two right or the two left halves of the visual fields of both eyes. It is caused by lesions of the retrochiasmal visual pathways, ie, lesions of the optic tract, the lateral geniculate nucleus, the optic radiations, and the cerebral visual (occipital) cortex
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 17
Correct
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What is the approximate lifespan of the mature erythrocyte:
Your Answer: 120 days
Explanation:Erythrocytes have a normal lifespan of about 120 days. Mature erythrocytes are biconcave discs with no nucleus, ribosomes or mitochondria but with the ability to generate energy as ATP by the anaerobic glycolytic pathway. The red cell membrane consists of a bipolar lipid layer with a membrane skeleton of penetrating and integral proteins anchoring carbohydrate surface antigens. The shape and flexibility of red cells allows them to deform easily and pass through capillaries.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 18
Incorrect
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Regarding the factor V Leiden gene mutation, which of the following best describes the clinical effect:
Your Answer: It results in deficiency of factor V.
Correct Answer: It results in increased levels of activated factor V.
Explanation:Factor V Leiden gene mutation is the most common inherited cause of an increased risk of venous thrombosis. Activated protein C normally breaks down activated factor V and so should slow the clotting reaction and prolong the APTT, but a mutation in the factor V gene makes factor V less susceptible to cleavage by activated protein C, resulting in increased levels of activated factor V.Heterozygotes for factor V Leiden are at an approximately five- to eight- fold increased risk of venous thrombosis compared to the general population (but only 10% of carriers will develop thrombosis in their lifetime). Homozygotes have a 30 – 140-fold increased risk. The incidence of factor V Leiden in patients with venous thrombosis is approximately 20 – 40%. It does not increase the risk of arterial thrombosis.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 19
Incorrect
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You are prescribing ipratropium bromide for a patient who has presented with an exacerbation of her COPD. What is the mechanism of action of ipratropium bromide:
Your Answer: Muscarinic agonist
Correct Answer: Muscarinic antagonist
Explanation:Ipratropium bromide is an antimuscarinic drug used in the management of acute asthma and COPD. It can provide short-term relief in chronic asthma, but short-acting β2agonists act more quickly and are preferred.
The BTS guidelines recommend that nebulised ipratropium bromide (0.5 mg 4-6 hourly) can be added to β2agonist treatment for patients with acute severe or life-threatening asthma or those with a poor initial response to β2 agonist therapy.
The aerosol inhalation of ipratropium can be used for short-term relief in mild chronic obstructive pulmonary disease in patients who are not already using a long-acting antimuscarinic drug (e.g. tiotropium).Its maximum effect occurs 30-60 minutes after use; its duration of action is 3-6 hours, and bronchodilation can usually be maintained with treatment three times per day.
The commonest side effect of ipratropium bromide is dry mouth. It can also trigger acute closed-angle glaucoma in susceptible patients. Tremor is commonly seen with β2agonists but not with antimuscarinics. Ipratropium bromide should be used with caution in: Men with prostatic hyperplasia and bladder-outflow obstruction (worsened urinary retention has been reported in elderly men), People with chronic kidney disease (CKD) stages 3 and above (because of the risk of drug toxicity), People with angle-closure glaucoma (nebulised mist of antimuscarinic drugs can precipitate or worsen acute angle-closure glaucoma) -
This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 20
Incorrect
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A patient is diagnosed with a Klebsiella infection.
Which SINGLE statement regarding Klebsiella infections is true?Your Answer: Species with ESBLs are sensitive to ceftriaxone
Correct Answer: Klebsiella spp are an important cause of ventilator-associated pneumonia
Explanation:Klebsiellais a genus of non-motile,Gram-negative, rod-shaped bacteriawith a prominent polysaccharide-based capsule. They are routinely found in the nose, mouth and gastrointestinal tract as normal flora, however, they can also behave as opportunistic pathogens.
Infections with Klebsiella spp. areusually nosocomial. They are an important cause of ventilator-associated pneumonia (VAP), urinary tract infection, wound infection and bacteraemia. Outbreaks of infections with Klebsiellaspp. in high-dependency units have been described and are associated with septicaemia and high mortality rates. Length of hospital stay and performance of invasive procedures are risk factors forKlebsiellainfections.
Primary pneumonia withKlebsiella pneumoniaeis a rare,severe, community-acquired infection associated with a poor outcome.
Klebsiella rhinoscleromatis causes a progressive granulomatous infection of the nasal passages and surrounding mucous membranes. This infection is mainly seen in the tropics.
Klebsiella ozanae is a recognised cause of chronic bronchiectasis.
Klebsiella organisms are resistant to multiple antibiotics including penicillins. This is thought to be a plasmid-mediated property. Agents with high intrinsic activity againstKlebsiellapneumoniaeshould be selected for severely ill patients. Examples of such agents include third-generation cephalosporins (e.g cefotaxime), carbapenems (e.g. imipenem), aminoglycosides (e.g. gentamicin), and quinolones (e.g. ciprofloxacin). These agents may be used as monotherapy or combination therapy. Aztreonam may be used in patients who are allergic to beta-lactam antibiotics.
Species with ESBLs (Extended spectrum beta-lactamase) are resistant to penicillins and also cephalosporins such as cefotaxime and ceftriaxone
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 21
Incorrect
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Aside from the inability to extend the leg above the knee, which of the following clinical symptoms should you anticipate seeing in a patient who had a pelvic and right leg injury as well as femoral nerve damage?
Your Answer: Weak dorsiflexion of the ankle
Correct Answer: Loss of sensation over the anterior thigh
Explanation:The femoral nerve runs down the front of the leg from the pelvis. It gives the front of the thigh and a portion of the lower leg sensation.
Extension of the leg at the knee joint, flexion of the thigh at the hip are produced by muscles that is primarily innervated by the femoral nerve.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 22
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:
Glycogenolysis
Gluconeogenesis
Lipolysis in adipose tissue
The secretion of glucagon is also stimulated by:
Adrenaline
Cholecystokinin
Arginine
Alanine
Acetylcholine
The secretion of glucagon is inhibited by:
Insulin
Somatostatin
Increased free fatty acids
Increased urea productionGlycolysis is the metabolic pathway that converts glucose into pyruvate. The free energy released by this process is used to form ATP and NADH. Glycolysis is inhibited by glucagon, and glycolysis and gluconeogenesis are reciprocally regulated so that when one cell pathway is activated, the other is inactive and vice versa.
Glucagon has a minor effect of enhancing lipolysis in adipose tissue. Lipolysis is the breakdown of lipids and involves the hydrolysis of triglycerides into glycerol and free fatty acids. It makes fatty acids available for oxidation.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 23
Incorrect
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Which of these is NOT a lithium side effect:
Your Answer: Nephrotoxicity
Correct Answer: Peptic ulcer disease
Explanation:Adverse Effects of lithium Include
Leucocytosis (most patients)
Polyuria/polydipsia (30-50%)
Dry mouth (20-50%)
Hand tremor (45% initially, 10% after 1 year of treatment)
Confusion (40%)
Decreased memory (40%)
Headache (40%)
Muscle weakness (30% initially, 1% after 1 year of treatment)
Electrocardiographic (ECG) changes (20-30%)
Nausea, vomiting, diarrhoea (10-30% initially, 1-10% after 1-2 years of treatment)
Hyperreflexia (15%)
Muscle twitch (15%)
Vertigo (15%)
Extrapyramidal symptoms, goitre (5%)
Hypothyroidism (1-4%)
Acne (1%)
Hair thinning (1%) -
This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 24
Incorrect
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A 24-year-old athlete drinks a 500 ml hypertonic sports drink before an endurance event he participates in.
Which of the following effects will this cause?Your Answer:
Correct Answer: The interstitial fluid becomes more concentrated
Explanation:Osmosis is the passive movement of water across a semipermeable membrane from a region of low solute concentration to a region of higher solute concentration.
When hypertonic fluid is ingested:
The plasma becomes CONCENTRATED.The cells lose water and shrink
The intracellular fluid becomes more concentrated.
Water and ions move freely from the plasma into the interstitial fluid and the interstitial fluid becomes more concentrated.
The increased osmotic potential draws water out of the cells. -
This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 25
Incorrect
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A 36-year-old woman is 22-weeks pregnant and is investigated for a possible thyroid disorder. When her total thyroid hormone levels does not correlate with her thyrometabolic status, her thyroid-binding globulin levels are checked.
What percentage of circulating thyroid hormones is bound to thyroid-binding globulin?Your Answer:
Correct Answer: 70%
Explanation:Only a very small fraction of the thyroid hormones circulating in the blood are free. The majority is bound to transport proteins. Only the free thyroid hormones are biologically active, and measurement of total thyroid hormone levels can be misleading.
The relative percentages of bound and unbound thyroid hormones are:
Bound to thyroid-binding globulin -70%
Bound to albumin -15-20%
Bound to transthyretin -10-15%
Free T3 -0.3%
Free T4 -0.03% -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 26
Incorrect
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A 54-year-old woman presents with polyuria and polydipsia. She is known to suffer from bipolar disorder, which has been well controlled by the use of lithium for many years.
What is the SINGLE most likely diagnosis?Your Answer:
Correct Answer: Nephrogenic diabetes insipidus
Explanation:Diabetes insipidus is the inability to produce concentrated urine. It is characterised by the presence of excessive thirst, polyuria and polydipsia. There are two distinct types of diabetes insipidus:
Cranial (central) diabetes insipidus and;
Nephrogenic diabetes insipidus
Cranial diabetes insipidus is caused by a deficiency of vasopressin (anti-diuretic hormone). Patients with cranial diabetes insipidus can have a urine output as high as 10-15 litres per 24 hours, but adequate fluid intake allows most patients to maintain normonatraemia. 30% of cases are idiopathic, and a further 30% are secondary to head injuries. Other causes include neurosurgery, brain tumours, meningitis, granulomatous disease (e.g. sarcoidosis) and drugs, such as naloxone and phenytoin. A very rare inherited form also exists that is associated with diabetes mellitus, optic atrophy, nerve deafness and bladder atonia.
Nephrogenic diabetes insipidus is caused by renal resistance to the action of vasopressin. As with cranial diabetes insipidus, urine output is markedly elevated. Serum sodium levels can be maintained by secondary polydipsia or can be elevated. Causes of nephrogenic diabetes insipidus include chronic renal disease, metabolic disorders (e.g. hypercalcaemia and hypokalaemia) and drugs, including long-term lithium usage and demeclocycline.
In view of the history of long-term lithium use, in this case, nephrogenic diabetes insipidus is the most likely diagnosis. -
This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 27
Incorrect
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A patient complains of stomach ache. You see a midline scar in the epigastric area when you examine the abdomen. Upon further interrogation, the patient reveals that she had a subtotal gastrectomy for recurring stomach ulcers several years ago. The stomach mucosa secretes a variety of vital compounds, and her ability to secrete some of these molecules has been harmed as a result of his surgery.
The stomach D-cells secrete which of the following substances?
Your Answer:
Correct Answer: Somatostatin
Explanation:Somatostatin-producing cells present in the pyloric antrum, duodenum, and pancreatic islets are known as D-cells or delta-cells. Somatostatin inhibits gastric acid secretion by acting directly on acid-producing parietal cells in the stomach via a G-protein coupled receptor. By suppressing the release of other hormones such as gastrin, secretin, and histamine, somatostatin can indirectly reduce stomach acid output, slowing the digesting process.
The table below summarizes the many cell types found in the stomach, as well as the substances secreted by each cell type and the function of the secretion:Cell type/ Substance secreted/ Function of secretion
Parietal cells/ Hydrochloric acid/ Kills microbes and activates pepsinogen
Parietal cells/ Intrinsic factor/Binds to vitamin B12 and facilitates its absorption
Chief cells/ Pepsinogen/ Protein digestion
Chief cells/ Gastric lipase/ Fat digestion
G-cells/ Gastrin/ Stimulates gastric acid secretion
Enterochromaffin-like cells (ECL cells) /Histamine/ Stimulates gastric acid secretion
Mucous-neck cells/ Mucous and bicarbonate/ Protects stomach epithelium from acid
D-cells/ Somatostatin/ Inhibits gastric acid secretion -
This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 28
Incorrect
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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:
Correct 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 29
Incorrect
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Which of the following is NOT an advantage of a cohort study used to investigate the relationship between exposure to a risk factor and a future outcome:
Your Answer:
Correct Answer: Particularly suitable for rare diseases
Explanation:Advantages: ideal for studying associations between an exposure and an outcome when the exposure is uncommon, the time sequence of events can be assessed, they can provide information on a wide range of disease outcomes, the absolute and relative risk of disease can be measured directly, they can give a direct estimation of disease incidence rates
Disadvantages: costly and can take long periods of time if the outcome is delayed, subject to subject-selection and loss to follow-up bias, large sample size required for rare outcome of interest so it is not useful for rare diseases, prone to confounding -
This question is part of the following fields:
- Evidence Based Medicine
- Study Methodology
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Question 30
Incorrect
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You have been asked to give a tutorial on common upper limb neurology to a group of medical students. You use the example of a man falling from a balcony onto spiked fencing, sustaining a puncture wound to the axilla. This results in an injury to the musculocutaneous nerve. Which of the following clinical features would you LEAST expect to see in this patient:
Your Answer:
Correct Answer: Weakness of forearm pronation
Explanation:Flexion of the arm and flexion and supination of the forearm are weakened but not lost entirely due to the actions of the pectoralis major and deltoid, the brachioradialis and the supinator muscles respectively. There is loss of sensation over the lateral aspect of the forearm. Forearm pronation would not be affected as this is primarily produced by the pronator quadratus and pronator teres muscles, innervated by the median nerve.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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SESSION STATS - PERFORMANCE PER SPECIALTY
