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Question 1
Incorrect
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A 68-year-old patient shows Low calcium levels and is on dialysis for chronic kidney disease.
What percentage of total serum calcium is in the form of free or ionised Ca 2+?Your Answer: 10%
Correct Answer: 50%
Explanation:Approximately half of total serum calcium is in the free or ionised Ca2+ state, 40% is attached to plasma proteins (mostly albumin), and the remaining 10% is in complexes with organic ions like citrate and phosphate. The ionized form is the only one that works.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 2
Incorrect
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A 56-year-old male with a 10-year history of Diabetes Mellitus and Hypertension was rushed to the Emergency Department due to sudden onset crushing chest pain. ECG showed an ST-elevation myocardial infarct in the left anterior descending artery territory. The patient's condition was stabilised and managed with angioplasty, but he sustained significant myocardial damage.
Which one of the following statements best agrees with the myocardial healing process?Your Answer: The damaged myocardial cells will enter G1 from G0
Correct Answer: The left ventricle will likely hypertrophy first to maintain cardiac output
Explanation:Following a myocardial infarction scar tissue formation will take place at the site of the damaged muscle. This places increased load on the rest of the myocardium causing it to hypertrophy. The left ventricle will hypertrophy first as it is pumping blood against a greater afterload as compared to the right ventricle.
There are three types of cells in the body with regards to the cell cycle: 1. permanent
2. labile
3. stable cellsPermanent cells do not re-enter the cell cycle and remain in G0. If there is a pool of stem cells the stem cells will enter the cell cycle to form more cells. Myocardial cells are a type of permanent cell and there is no pool of stem cells in the heart muscle. The anterior wall will not hypertrophy as it is formed by the right atrium and ventricle and both of these hypertrophy after the left ventricle.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 3
Incorrect
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The following are all examples of type II hypersensitivity EXCEPT for:
Your Answer: Goodpasture's syndrome
Correct Answer: Post-streptococcal glomerulonephritis
Explanation:Examples of type II reactions include:
Incompatible blood transfusions
Haemolytic disease of the newborn
Autoimmune haemolytic anaemias
Goodpasture’s syndrome
Rheumatic heart disease
Bullous pemphigoid -
This question is part of the following fields:
- Immune Responses
- Pathology
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Question 4
Incorrect
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A patient has suffered a nerve injury that has caused weakness of the pectoralis minor muscle.
Pectoralis minor receives its innervation from which of the following nerves? Select ONE answer only.Your Answer: Lateral pectoral nerve
Correct Answer: Medial pectoral nerve
Explanation:Pectoralis minor is a thin, triangular muscle that is situated in the upper chest. It is thinner and smaller than pectoralis major. It is innervated by the medial pectoral nerve.
The origin of pectoralis minor is the 3rdto the 5thribs, near the costal cartilages. It inserts into the medial border and superior surface of the coracoid process of the scapula.
The main action of pectoralis minor is to draw the scapula inferiorly and anteriorly against the thoracic wall. This serves to stabilise the scapula. -
This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 5
Correct
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Regarding the penis, which of the following statements is CORRECT:
Your Answer: The corpus spongiosum is ventral in the erect penis.
Explanation:Because the anatomical position of the penis is erect, the paired corpora cavernosa are defined as dorsal in the body of the penis and the single corpus spongiosum as ventral. The nerves and vessels lie superficial to the corpus cavernosum. The urethra lies within the corpus spongiosum.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 6
Correct
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Platelet alpha granules release which of the following?
Your Answer: Von Willebrand factor (VWF)
Explanation:There are three types of storage granules contained in platelets. These are dense granules which contain the following:
-ATP
-ADP
-serotonin and calcium alpha granules containing clotting factors
-von Willebrand factor (VWF)
-platelet-derived growth factor (PDGF)
– other proteins lysosomes containing hydrolytic enzymes. -
This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 7
Incorrect
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Identify the type of graph described below:
This graph is a scatter plot of the effect estimates from individual studies against some measure of each study's size or precision.
Your Answer: Forest plot
Correct Answer: Funnel plot
Explanation:A funnel plot is a scatter plot of the effect estimates from individual studies against some measure of each study’s size or precision. The standard error of the effect estimate is often chosen as the measure of study size and plotted on the vertical axis with a reversed scale that places the larger, most powerful studies towards the top. The effect estimates from smaller studies should scatter more widely at the bottom, with the spread narrowing among larger studies. In the absence of bias and between study heterogeneity, the scatter will be due to sampling variation alone and the plot will resemble a symmetrical inverted funnel. A triangle centred on a fixed effect summary estimate and extending 1.96 standard errors either side will include about 95% of studies if no bias is present and the fixed effect assumption (that the true treatment effect is the same in each study) is valid.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 8
Correct
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Which of the following is the most common cause of megaloblastic anaemia:
Your Answer: Vitamin B12 deficiency
Explanation:Megaloblastic anemia results from inhibition of DNA synthesis during red blood cell production. When DNA synthesis is impaired, the cell cycle cannot progress from the growth stage to the mitosis stage. This leads to continuing cell growth without division, which presents as macrocytosis, with an increase in mean corpuscular volume (MCV). The defect in red cell DNA synthesis is most often due to hypovitaminosis, specifically vitamin B12 deficiency or folate deficiency.
Folate is an essential vitamin found in most foods, especially liver, green vegetables and yeast. The normal daily diet contains 200 – 250 μg, of which about 50% is absorbed. Daily adult requirements are about 100 μg. Absorption of folate is principally from the duodenum and jejunum. Stores of folate are normally only adequate for 4 months and so features of deficiency may be apparent after this time. -
This question is part of the following fields:
- Haematology
- Pathology
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Question 9
Incorrect
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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: External oblique aponeurosis
Correct 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 10
Correct
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Regarding the renin-angiotensin-aldosterone system (RAAS), which of the following statements is CORRECT:
Your Answer: Angiotensin II has a predominant vasoconstrictor effect on the efferent arteriole.
Explanation:Angiotensin II constricts both the afferent and efferent arterioles, but preferentially increases efferent resistance. The net effect of the more prominent increase in efferent tone is that the intraglomerular pressure is stable or increased, thereby tending to maintain or even raise the GFR. Renin is produced by granular cells of the juxtaglomerular apparatus. Renin cleaves plasma angiotensinogen (produced in the liver) into angiotensin I. Angiotensin I is converted by angiotensin-converting enzyme (ACE) on pulmonary endothelial cells to angiotensin II. Angiotensin II acts to potentiate sympathetic activity (positive feedback).
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This question is part of the following fields:
- Physiology
- Renal
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Question 11
Incorrect
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An analytical cohort study aimed to determine a relationship between intake of dietary calcium and incidence of hip fractures among post-menopausal women. The following are the data obtained from the study:
No. of post-menopausal women who took Calcium: 500
No. of post-menopausal women who took Calcium and suffered a hip fracture: 10
No. of post-menopausal women who took placebo: 500
No. of post-menopausal women who took placebo and suffered a hip fracture: 25
Compute for the absolute risk reduction of a hip fracture.Your Answer: None of the other options
Correct Answer: 0.03
Explanation:Absolute risk reduction (ARR) is computed as the difference between the absolute risk in the control group (ARC) and the absolute risk in the treatment group (ART).
ARR = ARC-ART
ARR = (25/500) – (10/500)
ARR = 0.03 -
This question is part of the following fields:
- Evidence Based Medicine
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Question 12
Incorrect
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Regarding the brachioradialis muscle, which of the following statements is true?
Your Answer: It is innervated by the musculocutaneous nerve
Correct Answer: It assists with supination of the forearm at the radioulnar joints
Explanation:Brachioradialis is a fusiform muscle located in the lateral part of the posterior forearm. Along with extensor carpi radialis brevis and extensor carpi radialis longus, it comprises the radial group of forearm muscles, which belong to the superficial layer of posterior forearm muscles. Although anatomically part of the posterior forearm muscles, which are known to be forearm extensors, brachioradialis’ fibre orientation enables it to rather flex the forearm, and aids in supination of the forearm at the radioulnar joint.
The brachioradialis muscle originates from the upper two-thirds of the lateral supracondylar ridge of humerus and the anterior surface of the lateral intermuscular septum of the arm. It slides over the lateral surface of the elbow joint, entering the anterolateral cubital area. The muscle fibres course inferiorly down the radial part of the anterior forearm, forming a thick tendon in approximately the middle of the forearm. This tendon then traverses the remainder of the forearm, inserting near the wrist, just proximal to the styloid process of radius.
Brachioradialis is innervated by the radial nerve (from the root values C5-C6) that stems from the posterior cord of the brachial plexus. Blood supply to the brachioradialis muscle comes from branches of the radial artery, radial recurrent artery and the radial collateral branch of the deep brachial artery.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 13
Correct
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Which of the following statements is correct with regards to Horner's syndrome?
Your Answer: Miosis occurs due to paralysis of the dilator pupillae muscle.
Explanation:The characteristics of Horner’s syndrome are pupil constriction, partial ptosis and anhidrosis.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 14
Correct
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A 29-year-old female with chronic anaemia secondary to sickle cell disease is being transfused. A few minutes after starting the blood transfusion, she develops widespread itching with urticarial rash, wheezing, nausea and chest pain. Her BP reduces to 60/40 mmHg.
What is the most appropriate treatment?Your Answer: Stop the transfusion and administer adrenaline
Explanation:Anaphylaxis transfusion reaction occurs when an individual has previously been sensitized to an allergen present in the blood and, on re-exposure, releases IgE or IgG antibodies. Patients with anaphylaxis usually develop laryngospasm, bronchospasm, abdominal pain, nausea, vomiting, hypotension, shock, and loss of consciousness. The transfusion should be stopped immediately and the patient should be treated with adrenaline, oxygen, corticosteroids, and antihistamines.
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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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Before a patient is discharged, you are asked to review them. He is a 59-year-old man who was seen with epigastric pain that has since subsided, and he will be seen by his GP in the coming days. He's been hearing a lot about aspirin lately and wants to learn more about it.
Which of the following statements about aspirin's mechanism of action is correct?Your Answer: Inhibition of cyclo-oxygenase
Explanation:Aspirin works by inhibiting cyclo-oxygenase in an irreversible manner, resulting in a decrease in prostaglandin and thromboxane production. As a result, platelet activation and aggregation are reduced.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 16
Incorrect
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You are reviewing a patient following a fall from a horse. You suspect they may have an Erb's palsy as a result of a brachial plexus injury. Regarding Erb's palsy, which one of the following statements is CORRECT:
Your Answer: Erb's palsy characteristically results in Waiter's tip deformity where the arm is held in lateral rotation.
Correct Answer: Erb's palsy may result in loss of sensation of the regimental badge area.
Explanation:Erb’s palsy is caused by damage to the C5 and C6 nerve roots and thus primarily involves the musculocutaneous, suprascapular and axillary nerves. It commonly result from an excessive increase in the angle between the neck and the shoulder e.g. a person thrown from a motorbike or horseback or during a difficult birth. There is loss or weakness of abduction, lateral rotation and flexion of the arm and flexion and supination of the forearm and loss of sensation on the lateral arm. A characteristic ‘Waiter’s tip’ deformity may be present where the limb hangs limply by the side, medially rotated by the unopposed action of pectoralis major with the forearm pronated due to paralysis of the biceps brachii.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 17
Correct
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Regarding the foetal oxygen-haemoglobin dissociation curve, which of the following statements is CORRECT:
Your Answer: The HbF dissociation curve lies to the left of that for HbA.
Explanation:Foetal haemoglobin (HbF) has a higher affinity for oxygen than adult haemoglobin (HbA) because it’s gamma chains bind 2,3-DPG less avidly than beta chains of HbA. The HbF dissociation curve lies to the left of that for HbA. In the placenta PCO2moves from the foetal to the maternal circulation, shifting the maternal curve further right and the foetal curve further left (the double Bohr effect). The higher affinity of HbF relative to HbA helps transfer oxygen from mother to foetus. Therefore even through blood returning from the placenta to the foetus in the umbilical vein has a PO2of only about 4 kPa, its saturation is 70%. Oxygen transport in the foetus is also helped by a high Hb of about 170 – 180 g/L.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 18
Correct
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Which of the following nerves has been damaged when a patient presents with a foot drop?
Your Answer: Common peroneal nerve
Explanation:The common peroneal nerve often referred to as the common fibular nerve, is a major nerve that innervates the lower extremity. It is one of the two major branches off the sciatic nerve and receives fibres from the posterior divisions of L4 through S2 nerve roots. The common peroneal nerve separates from the sciatic nerve in the distal posterior thigh proximal to the popliteal fossa. After branching off of the sciatic nerve, it continues down the thigh, running posteroinferior to the biceps femoris muscle, and crosses laterally to the head of the lateral gastrocnemius muscle through the posterior intermuscular septum. The nerve then curves around the fibular neck before dividing into two branches, the superficial peroneal nerve (SPN) and the deep peroneal nerve (DPN). The common peroneal nerve does not have any motor innervation before dividing; however, it provides sensory innervation to the lateral leg via the lateral sural nerve.
The superficial peroneal nerve innervates the lateral compartment of the leg, and the deep peroneal nerve innervates the anterior compartment of the leg and the dorsum of the foot. These two nerves are essential in the eversion of the foot and dorsiflexion of the foot, respectively. The superficial and deep peroneal nerves provide both motor and sensory innervation.
The most common presentation with common peroneal nerve injury or palsy is acute foot drop, although symptoms may be progressive and can include sensory loss or pain. Weakness in foot eversion may occur if the superficial peroneal nerve component is involved.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 19
Incorrect
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A 25 year old man presents to the emergency room with abdominal pain, vomiting and constipation. A CT scan is done which is suggestive of Meckel's diverticulum. Where does the blood supply of the Meckel's diverticulum originate?
Your Answer: Inferior mesenteric artery
Correct Answer: Superior mesenteric artery
Explanation:Meckel’s diverticulum has certain classic characteristics.
1. It lies on the antimesenteric border of the middle-to-distal ileum
2. It is approximately 2 feet proximal to the ileocaecal junction
3. It appears as a blind-ended tubular outpouching of bowel
4. It is about 2 inches long,
5. It occurs in about 2% of the population,
6. It may contain two types of ectopic tissue (gastric and pancreatic).
7. The diverticulum is supplied by the superior mesenteric artery.
8. Proximal to the major duodenal papilla the duodenum is supplied by the gastroduodenal artery (branch of the coeliac trunk)
9. Distal to the major duodenal papilla it is supplied by the inferior pancreaticoduodenal artery (branch of superior mesenteric artery).
10. The arterial supply to the jejunoileum is from the superior mesenteric artery. -
This question is part of the following fields:
- Abdomen
- Anatomy
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Question 20
Incorrect
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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: Kaplan-Meier 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) -
This question is part of the following fields:
- Evidence Based Medicine
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Question 21
Incorrect
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Regarding bronchiolitis, which of the following statements is CORRECT:
Your Answer: Crepitations on auscultation would suggest an alternative diagnosis.
Correct Answer: Chest x-ray may show hyperinflation and increased peribronchial markings.
Explanation:Acute bronchiolitis is caused most commonly by respiratory syncytial virus, occurring mostly in children aged 6 months to 2 years. Children with bronchiolitis are febrile and tachypnoeic with a dry cough and difficulty feeding. Examination may reveal chest hyperinflation, respiratory distress, wheezing and fine end-inspiratory crepitations. Chest x-ray may show hyperinflation and increased peribronchial markings (although CXR should only performed if there is diagnostic uncertainty or an atypical course). Treatment is usually supportive, aerosolized ribavirin is reserved for severely ill or immunocompromised patients.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 22
Correct
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Insulin binds to the insulin receptor (IR) on cell surfaces to exert its action. The IR is a very specific transmembrane receptor belonging to the tyrosine kinase receptor class.
One of these also activates the IR:
Your Answer: IGF-I
Explanation:Insulin receptor (IR), in addition to being activated by insulin, is also activated by IGF-I and IGF-II.
The IR is a dimer with two identical subunits spanning the cell membrane and are connected by a single disulphide bond. The two sub-units include: The alpha chain situated on the exterior of the cell membrane and the beta chain spanning the cell membrane in a single segment.
When insulin is detected, the alpha chains move together folding around the insulin making the beta chains move together, converting them into an active tyrosine kinase. This initiates a phosphorylation cascade increasing the expression of GLUT4 and allowing uptake of glucose by cells.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 23
Correct
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The risk of renal impairment in a patient on ACE inhibitor therapy is increased by concomitant treatment with which of the following drug classes:
Your Answer: NSAIDs
Explanation:Concomitant treatment with NSAIDs increases the risk of renal damage, and with potassium-sparing diuretics (or potassium-containing salt substitutes) increases the risk of hyperkalaemia. Hyperkalaemia and other side effects of ACE inhibitors are more common in the elderly and in those with impaired renal function and the dose may need to be reduced.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 24
Correct
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A 57-year-old woman has presented with cough and shortness of breath. Her GP had done some blood tests recently and told her that she had a positive ANA result.
Which of these statements is true about anti-nuclear antibodies (ANAs)? Select only ONE answer.
Your Answer: The presence of ANAs in rheumatoid arthritis is suggestive of Felty’s syndrome
Explanation:Anti-nuclear antibodies are auto-antibodies directed against a variety of nuclear antigens. There are different staining patterns and each pattern is suggestive of a different disorder.
Speckled staining is suggestive of mixed connective tissue disease.
Nucleolar staining is suggestive of scleroderma, while homogenous staining is suggestive of lupus.
Anti-double stranded DNA is suggestive of SLE while anti-histone antibodies are suggestive of drug-induced lupus.
ELISA testing is cheaper but not the most accurate means of testing for ANAs. Indirect immunofluorescence testing is the most accurate.
The presence of ANAs in rheumatoid arthritis is suggestive of Felty’s syndrome. Felty’s syndrome is characterized by a combination of rheumatoid arthritis, splenomegaly and neutropenia.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 25
Correct
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Epigastric pain and haematemesis present in a 67-year-old man. In the emergency room, he is stabilised and referred to the on-call medical team. He has been scheduled for an endoscopy in the morning due to a suspected peptic ulcer. Before transferring him to the ward, you consider giving him a proton pump inhibitor (PPI).
Which of the following doses and routes are the best?Your Answer: A PPI should not be prescribed
Explanation:PPIs should not be used prior to endoscopic therapy when an early endoscopic examination is performed within 24 hours of admission, according to current recommendations.
High-dose PPI therapy reduces the risk of rebleeding and surgery after endoscopic treatment of severe peptic ulcer bleeding. Both oral and intravenous PPIs produce similar results, and there is no discernible benefit to using the intravenous formulation in patients who can tolerate oral medication. -
This question is part of the following fields:
- Gastrointestinal Pharmacology
- Pharmacology
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Question 26
Correct
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A 29 year old man presents to ED followed an alleged assault whilst out drinking. He received blunt trauma to his right axilla. He is complaining of difficulty abducting his right arm above the level of his shoulder, and on inspection, the inferior angle of his right scapula protrudes more than that of his left scapula. Which of the following nerves has most likely been affected:
Your Answer: Long thoracic nerve
Explanation:Damage to the long thoracic nerve results in weakness/paralysis of the serratus anterior muscle causing difficulty abducting the upper limb above 90 degrees and giving a ‘winged ‘ scapula appearance where the medial border, particularly the inferior angle, of the scapula moves laterally and posteriorly away from the thoracic wall (this becomes more pronounced if the patient presses the upper limb against a wall).
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 27
Correct
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You assess a patient that has suffered a nerve injury that has paralysed her left latissimus dorsi muscle.
Latissimus dorsi receives its innervation from which of the following nerves? Select ONE answer only.Your Answer: Thoracodorsal nerve
Explanation:Latissimus dorsi originates from the lower part of the back, where it covers a wide area. It lies underneath the inferior fibres of trapezius superiorly, and trapezius is the most superficial back muscle.
Superficial muscles of the back showing latissimus dorsi (from Gray’s Anatomy)
Latissimus dorsi has a broad origin, arising from the spinous processes of T6-T12, the thoracolumbar fascia, the iliac crest and the inferior 3 or 4 ribs. The fibres converge into a tendon that inserts into the intertubercular groove of the humerus.
Latissimus dorsi is innervated by the thoracodorsal nerve.
Latissimus dorsi acts to extend, adduct and medially rotate the humerus. It, therefore, raises the body towards the arm during climbing. -
This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 28
Incorrect
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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: Thyroxine
Correct Answer: Parathyroid hormone
Explanation:Parathyroid hormone (PTH), a polypeptide containing 84 amino acids, is the principal hormone that controls free calcium in the body.
Its main actions are:
Increases osteoclastic activity
Increases plasma calcium concentration
Decreases renal phosphate reabsorption
Decreases plasma phosphate concentration
Increases renal tubular reabsorption of calcium
Increases calcium and phosphate absorption in the small intestine
Increases renal conversion of 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 29
Correct
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What is the primary function of the mitochondria?
Your Answer: The production of the cell's supply of chemical energy
Explanation:The mitochondria is responsible for the production of the cell’s supply of chemical energy. It does this by using molecular oxygen, sugar and small fatty acid molecules to generate adenosine triphosphate (ATP) by a process ss known as oxidative phosphorylation. An enzyme called ATP synthase is required.
Transcription of ribosomal RNA occurs in the nucleolus
Production of messenger RNA occur in the nucleus
Production of lysosome occurs in the Golgi apparatus
The post-translational processing of newly made proteins occurs in the endoplasmic reticulum
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This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 30
Correct
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A 58-year-old man presented to the emergency room complaining of a chest pain that has been going on for the past 12 hours. Upon further investigation, a troponin test was ordered and the results came back negative. He was given a discharge order from the emergency department.
Which of the following aspects of this test is considered the most significant in the decision made that it was safe to send the patient home?Your Answer: Likelihood ratio
Explanation:The Likelihood Ratio (LR) is the likelihood that a given test result would be expected in a patient with the target disorder compared to the likelihood that that same result would be expected in a patient without the target disorder.
The LR is used to assess how good a diagnostic test is and to help in selecting an appropriate diagnostic tests or sequence of tests. They have advantages over sensitivity and specificity because they are less likely to change with the prevalence of the disorder, they can be calculated for several levels of the symptom/sign or test, they can be used to combine the results of multiple diagnostic test and they can be used to calculate post-test probability for a target disorder.
A LR greater than 1 produces a post-test probability which is higher than the pre-test probability. An LR less than 1 produces a post-test probability which is lower than the pre-test probability. When the pre-test probability lies between 30 and 70 per cent, test results with a very high LR (say, above 10) rule in disease. An LR below 1 produces a post-test probability les than the pre-test probability. A very low LR (say, below 0.1) virtually rules out the chance that the patient has the disease.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 31
Incorrect
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A patient is diagnosed with a Klebsiella pneumoniae infection.
Which SINGLE statement regarding Klebsiella pneumoniae is FALSE?Your Answer: Length of hospital stay and performance of invasive procedures are risk factors for infection
Correct Answer: Species with ESBLs are sensitive to cefotaxime
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 32
Correct
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A patient is referred for lung function tests on account of a history of breathlessness and cough.
Which statement about lung volumes is correct?
Your Answer: The tidal volume is the volume of air drawn in and out of the lungs during normal breathing
Explanation:The tidal volume(TV) is the amount of air that moves in and out of the lungs with each respiratory cycle. In a healthy male, the usual volume is 0.5 L (,7 ml/kg body mass).
The vital capacity(VC) is the maximum amount of air that can be exhaled following maximal inspiration. The usual volume in a healthy male is 4.5 L.
The residual volume(RV) is the amount of air remaining in the lungs after maximum expiration. The usual volume in a healthy male is 1.0 L.
The inspiratory reserve volume(IRV) is the maximum amount of air that can be breathed in forcibly after normal inspiration. The usual volume in a healthy male is 3.0 L.
The expiratory reserve volume(ERV) is the volume of air that can be breathed out forcibly after normal expiration. The usual volume in a healthy male is 1.0 L.
Total lung capacity(TLC) is the volume of air the lungs can accommodate. TLC = RV+VC. The usual volume in a healthy male is 5.5 L.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 33
Correct
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Most of the lymph from vessels that drain the breast is collected in which of the following lymph nodes?
Your Answer: Axillary nodes
Explanation:Lymph is the fluid that flows through the lymphatic system.
Axillary lymph nodes are near the breasts. They are often the first location to which breast cancer spreads if it moves beyond the breast tissue. They receive approximately 75% of lymph drainage from the breast via lymphatic vessels, laterally and superiorly.
The lymph usually first drains to the anterior axillary nodes, and from here, through the central axillary, apical, and supraclavicular nodes in sequence.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 34
Correct
-
Which of the following muscles are primarily involved in passive inspiration:
Your Answer: Diaphragm and external intercostal muscles
Explanation:Passive inspiration is produced by contraction of the diaphragm (depressing the diaphragm) and the external intercostal muscles (elevating the ribs). In inspiration, elevation of the sternal ends of the ribs (‘pump handle’ movement), elevation of the lateral shafts of the ribs (‘bucket handle’ movement) and depression of the diaphragm result in expansion of the thorax in an anteroposterior, transverse and vertical direction respectively. This results in an increased intrathoracic volume and decreased intrathoracic pressure and thus air is drawn into the lungs.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 35
Correct
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Question 36
Correct
-
A 17-year-old patient with a headache, fever, and a non-blanching rash is brought to the emergency room. Meningococcal infection is confirmed by a lumbar puncture. Neisseria meningitidis uses one of the following immune evasion mechanisms:
Your Answer: Secretes IgA protease
Explanation:Meningococci have 3 important virulence factors, as follows:
Polysaccharide capsule – Individuals with immunity against meningococcal infections have bactericidal antibodies against cell wall antigens and capsular polysaccharides; a deficiency of circulating anti meningococcal antibodies is associated with the disease.
Lipo-oligosaccharide endotoxin (LOS)
Immunoglobulin A1 (IgA1) -
This question is part of the following fields:
- Microbiology
- Principles
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Question 37
Incorrect
-
A 55-year-old woman with history of gastritis and reflux esophagitis tested positive for Helicobacter pylori infection.
Which of the following statements regarding Helicobacter pylori is considered true?Your Answer: It is an obligate anaerobe
Correct Answer: It is helix shaped
Explanation:Helicobacter pylori is a curved or helix-shaped, non-spore forming, Gram-negative, microaerophilic bacteria. It is motile, having multiple flagella at one pole. It has a lipopolysaccharide component in its outer membrane.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 38
Correct
-
Which of the following statements concerning the facial nerve is INCORRECT?
Your Answer: Forehead sparing in facial nerve palsy is indicative of a lower motor neuron lesion.
Explanation:In facial nerve palsy, LMN damage will involve the forehead and there will be an inability to close the eyes due to paralysis of the orbicularis oculi or raise the eyebrows due to paralysis of the occipitofrontalis muscle.
UMN damage causes sparing of the forehead as the occipitofrontalis and orbicularis oculi muscles have bilateral cortical representation. -
This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
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Question 39
Correct
-
Which of the following movements is controlled by the pectoralis major muscle?
Your Answer: Flexion, adduction and medial rotation of the humerus
Explanation:The pectoralis major is a muscle that runs across the top of the chest and connects to a ridge on the back of the humerus (the bone of the upper arm).
Adduction, or lowering, of the arm (opposed to the deltoideus muscle) and rotation of the arm forward around the axis of the body are two of its main functions.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 40
Correct
-
Which of the following leukaemias is most common in children in the UK:
Your Answer: Acute lymphoblastic leukaemia
Explanation:Acute lymphoblastic leukaemia (ALL) is caused by an accumulation of lymphoblasts in the bone marrow and is the most common malignancy of childhood. The incidence of ALL is highest at 3 – 7 years, with 75% of cases occurring before the age of 6. There is a secondary rise after the age of 40 years. 85% of cases are of B-cell lineage and have an equal sex incidence; there is a male predominance for the 15% of T-cell lineage.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 41
Correct
-
Which of the following statements accurately describes the number needed to harm?
Your Answer: The NNH is the number of patients that need to be treated for one to experience the side effect
Explanation:Number needed to harm (NNH) corresponds to the number of individuals that must be treated, so that one of them presents an adverse reaction accountable to the treatment.
Hence, a NNH of 100 means that 100 individuals need to be treated in order to produce an adverse effect of the treatment in one individual.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 42
Correct
-
An elderly man with chronic heart and lung disease develops Legionnaires' Disease. By what route was the infection most likely to have been acquired:
Your Answer: Inhalation of aerosolised contaminated water
Explanation:Legionella pneumophilais a Gram negative bacterium that is found in natural water supplies and in the soil, transmitted predominantly via inhalation of aerosols generated from contaminated water (direct person-to-person spread of infected patients does not occur). It is the cause of Legionnaires’ disease. Outbreaks of Legionnaires’ disease have been linked to poorly maintained air conditioning systems, whirlpool spas and hot tubs.
The clinical features of the pneumonic form of Legionnaires’ disease include:
Mild flu-like prodrome for 1-3 days
Cough (usually non-productive and occurs in approximately 90%)
Pleuritic chest pain
Haemoptysis
Headache
Nausea, vomiting and diarrhoea
Anorexia
Legionella pneumophilainfections can be successfully treated with macrolide antibiotics, such as erythromycin, or quinolones, such as ciprofloxacin. Tetracyclines, such as doxycycline, can also be used.
The syndrome of inappropriate antidiuretic hormone secretion (SIADH) can occur with Legionnaires’ disease and will result in hyponatraemia as is seen in this case.
Legionella pneumophilainfections are resistant to amoxicillin but can be successfully treated with macrolide antibiotics, such as erythromycin, or quinolones, such as ciprofloxacin. Tetracyclines, such as doxycycline, can also be used. The majority of cases of Legionnaires’ disease are caused by Legionella pneumophila, however many other species of Legionella have been identified.
Legionella longbeachae is another less commonly encountered species that has also been implicated in outbreaks. It is predominantly found in soil and potting compost, and has caused outbreaks of Pontiac fever, the non-respiratory and less severe variant of Legionnaires’ disease. -
This question is part of the following fields:
- Microbiology
- Pathogens
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Question 43
Incorrect
-
Which of the following presentations is NOT consistent with the diagnosis of anaphylaxis following exposure to a known allergen:
Your Answer: Hypotension alone
Correct Answer: Generalised urticaria and angioedema alone
Explanation:Anaphylaxis is characterised by sudden onset and rapidly developing, life-threatening airway, breathing and circulation problems associated with skin and/or mucosal changes. Reactions can vary greatly, from hypotension alone, to reactions with predominantly asthmatic features, to cardiac/respiratory arrest. Skin or mucosal changes may be absent or subtle in up to 20% of cases but skin or mucosal changes alone are not a sign of an anaphylactic reaction.
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 44
Correct
-
A 33-year-old woman who is investigated for recurrent renal stones is discovered to have a markedly elevated parathyroid hormone (PTH) level.
Which of the following would stimulate PTH release under normal circumstances? Select ONE answer only.Your Answer: Decreased plasma calcium concentration
Explanation:Parathyroid hormone (PTH) is a polypeptide containing 84 amino acids. It is the principal controller of free calcium in the body.
PTH is synthesised by and released from the chief cells of the four parathyroid glands that are located immediately behind the thyroid gland.
PTH is released in response to the following stimuli:
Decreased plasma calcium concentration
Increased plasma phosphate concentration (indirectly by binding to plasma calcium and reducing the calcium concentration)
PTH release is inhibited by the following factors:
Normal/increased plasma calcium concentration
Hypomagnesaemia
The main actions of PTH are:
Increases plasma calcium concentration
Decreases plasma phosphate concentration
Increases osteoclastic activity (increasing calcium and phosphate resorption from bone)
Increases renal tubular reabsorption of calcium
Decreases renal phosphate reabsorption
Increases 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) -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 45
Incorrect
-
A 69-year-old man presents with a painful groin swelling on the right side. The suspected diagnosis is an inguinal hernia.
Which of the following examination features make it more likely to be an indirect inguinal hernia?Your Answer: It can be reduced superiorly then posteriorly
Correct Answer: It can be controlled by pressure over the deep inguinal ring
Explanation:The reduced indirect inguinal hernia can be controlled by pressure over the internal ring; a direct inguinal hernia cannot.
An indirect inguinal hernia can be reduced superiorly then superolaterally, while a direct inguinal hernia can be reduced superiorly then posteriorly.
An indirect inguinal hernia takes time to reach full size, but a direct inguinal hernia appears immediately upon standing.
Indirect inguinal hernias are seen as elliptical swelling, while direct inguinal hernias appear as symmetric, circular swelling.
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This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
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Question 46
Correct
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Question 47
Correct
-
About case-control studies, one of the following is true.
Your Answer: They are suitable to be used in the study of rare diseases
Explanation:Case-control studies are suitable when investigating a rare disease or in cases where little is known about the disease and the proposed aetiological factor, as a preliminary study. They have the ability to look at multiple risk-factors (exposures) but can only look at a single outcome.
In a case-control study, two groups of patients, one with the disease and one without, are compared on the basis of a proposed causative factor that occurred in the past. They are therefore a retrospective study and useful in hypothesis generation.
Cohort studies are better at identifying rare exposures. One group with an exposure is compared to a control group without that exposure.
Case-control studies are usually less expensive to run and also shorter in duration compared with prospective cohort studies.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 48
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 49
Correct
-
Which of the following neurotransmitter and receptor combinations is present at the neuromuscular junction:
Your Answer: Acetylcholine acting at nicotinic receptors
Explanation:At the neuromuscular junction, acetylcholine is released from the prejunctional membrane which acts on cholinergic nicotinic receptors on the postjunctional membrane.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 50
Correct
-
When a person changes from a supine to an upright position, which of the followingcompensatory mechanismsoccurs:
Your Answer: Increased contractility
Explanation:On standing from a prone position, gravity causes blood to pool in veins in the legs. Central venous pressure (CVP) falls, causing a fall in stroke volume and cardiac output (due to Starling’s law) and thus a fall in blood pressure. Normally this fall in BP is rapidly corrected by the baroreceptor reflex which causes venoconstriction (partially restoring CVP), and an increase in heart rate and contractility, so restoring cardiac output and blood pressure. Impaired autonomic nervous activity in the elderly accounts for the greater likelihood of postural hypotension. Any symptoms of dizziness, blurred vision or syncope is due to a transient fall in cerebral perfusion that occurs before cardiac output and mean arterial pressure (MAP) can be corrected.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 51
Correct
-
A patient has a diagnosis of acute osteomyelitis. They have no joint prosthesis on indwelling metal work and no known drug allergies. He has had a recent skin swab that has cultured MRSA and MRSA infection is suspected.
Which of the following antibacterial agents would be most appropriate to prescribe in this case? Select ONE answer only.Your Answer: Vancomycin
Explanation:In the majority of patients the commonest causative organism for osteomyelitis isStaphylococcus aureus.Salmonella spp. are the commonest cause in patients with sickle cell disease.
Other bacteria that can cause osteomyelitis include:
Enterobacter spp.
Group A and B streptococcus
Haemophilus influenzae
The current recommendations by NICE and the BNF on the treatment of osteomyelitis are:
Flucloxacillin first-line
Consider adding fusidic acid or rifampicin for initial 2 weeks
If penicillin allergic use clindamycin
If MRSA is suspected use vancomycin
Suggested duration of treatment is 6 weeks for acute infection -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 52
Incorrect
-
What type of visual field defect are you likely to see in a lesion of the visual cortex:
Your Answer: Contralateral homonymous inferior quadrantanopia
Correct Answer: Contralateral homonymous hemianopia with macular sparing
Explanation:A lesion of the visual cortex will result in a contralateral homonymous hemianopia with macular sparing.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 53
Incorrect
-
The proximal convoluted tubule (PCT) is the first part of the renal tubule and lies in the renal cortex. The bulk of reabsorption of solute occurs is the PCT and 100% of glucose is reabsorbed here.
Which of the following is the mechanism of glucose reabsorption in the PCT?Your Answer: Simple diffusion
Correct Answer: Secondary active transport
Explanation:Glucose reabsorption occurs exclusively in the proximal convoluted tubule by secondary active transport through the Na.Glu co-transporters, driven by the electrochemical gradient for sodium.
The co-transporters transport two sodium ions and one glucose molecule across the apical membrane, and the glucose subsequently crosses the basolateral membrane by facilitated diffusion. -
This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 54
Correct
-
A patient was diagnosed with Erb's palsy as a result of a brachial plexus injury sustained in a car accident and, as a result, suffers from left arm paralysis. The following muscles are affected by the injury, except
Your Answer: Trapezius
Explanation:Damage to the C5 and C6 nerve roots causes Erb’s palsy.
The spinal accessory nerve (CN XI) innervates the trapezius muscle, thus you would not expect this muscle to be impacted.
The trapezius is a muscle that runs from the base of the neck across the shoulders and into the centre of the back.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 55
Incorrect
-
Regarding Clostridium tetani, which of the following statements is CORRECT:
Your Answer: It produces exotoxins A and B and binary toxin.
Correct Answer: Infection is predominantly derived from animal faeces and soil.
Explanation:Clostridium tetaniis a Gram positive, rod shaped, obligate anaerobic bacterium.
The incubation period is quoted as anywhere between 4-21 days and can occur after several months but symptoms usually occur within the first 7 days after exposure.
Approximately 80% of patients develop generalised tetanus. The commonest presenting feature of generalised tetanus is trismus (lockjaw), occurring in approximately 75% of affected individuals. Other clinical features include:
Facial spasms (risus sardonicus)
Opisthotonus (characteristic body shape during spasms)
Neck stiffness
Dysphagia
Calf and pectoral muscle rigidity
Fever
Hypertension
Tachycardia
Spasms can occur frequently and last for several minutes, they can continue to occur for up to 4 weeks. Current mortality rates are between 10 and 15%.
Tetanic spasms are caused by the exotoxin tetanospasmin. The effects of tetanolysin are not fully understood but it is not believed to have clinical significance.
Localised tetanus is a rare form of the disease, occurring in around 1% of affected individuals. Patients have persistent contraction of muscles in the same anatomic area as the injury. It may precede generalised tetanus. -
This question is part of the following fields:
- Microbiology
- Pathogens
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Question 56
Incorrect
-
A 45-year-old woman presents with persistent palpitations for the past two days. She has a good haemodynamic balance. An ECG is performed, which reveals that she has atrial flutter. The patient is examined by a cardiology registrar, who recommends using a 'rate control' strategy while she waits for cardioversion.
Which of the drugs listed below is the best fit for this strategy?Your Answer: Amiodarone
Correct Answer: Bisoprolol
Explanation:In atrial flutter, ventricular rate control is usually used as a stopgap measure until sinus rhythm can be restored. A beta-blocker (such as bisoprolol), diltiazem, or verapamil can be used to lower the heart rate.
Electrical cardioversion, pharmacological cardioversion, or catheter ablation can all be used to restore sinus rhythm. Cardioversion should not be attempted until the patient has been fully anticoagulated for at least three weeks if the duration of atrial flutter is unknown or has lasted for more than 48 hours. Emergency electrical cardioversion is the treatment of choice when there is an acute presentation with haemodynamic compromise. For the treatment of recurrent atrial flutter, catheter ablation is preferred.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 57
Correct
-
A 61-year-old patient experiences a spontaneous rupture of his Achilles tendon following a course of antibiotics
Which of the antibiotics listed below is MOSTÂ likely to be the cause?ÂYour Answer: Ciprofloxacin
Explanation:Tendinopathy and spontaneous tendon rupture are caused by fluoroquinolones, which are an uncommon but well-known cause. Tendon problems caused by fluoroquinolones are expected to affect 15 to 20 people per 100,000. Patients over the age of 60 are most likely to develop them.
It usually affects the Achilles tendon, but it has also been described in cases involving the quadriceps, peroneus brevis, extensor pollicis longus, long head of biceps brachii, and rotator cuff tendons. The exact aetiology is uncertain, although the fluoroquinolone medication is thought to obstruct collagen activity and/or cut off blood supply to the tendon.
Other factors linked to tendon rupture spontaneously include:
Gout
Treatment with corticosteroids
Hypercholesterolaemia
Long-term dialysis
Kidney transplant
Rheumatoid arthritis -
This question is part of the following fields:
- Infections
- Pharmacology
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Question 58
Correct
-
By the third day of wound healing, which sort of inflammatory cell has predominated:
Your Answer: Macrophages
Explanation:The inflammatory phase of healing is sometimes called the lag phase because wound strength does not begin to return immediately. The inflammatory phase is completed within three days except in the presence of infection or other factors associated with impaired wound healing. Mononuclear leukocytes accumulate and are transformed into macrophages. The maturation of blood-derived monocytes into macrophages is heralded by several events, including secretion of vimentin, which is a structural filament protein involved in wound healing.
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This question is part of the following fields:
- Pathology
- Wound Healing
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Question 59
Correct
-
An 85-year-old woman is brought in from her nursing home. She arrives in the Emergency Department and appears confused. The staff member from the nursing home accompanying her informs you that she takes a water tablet.
From her past medical history and records, you deduce that the water tablet is a loop diuretic.
Which of the following parts of a nephron does a loop diuretic act on?Your Answer: Ascending loop of Henlé
Explanation:Loop diuretics are drugs used to manage and treat fluid overload associated with CHF, liver cirrhosis, and renal disease. The drugs commonly used are:
Furosemide
Bumetanide
Torsemide
Ethacrynic AcidLoop diuretics act on the apical membrane of the thick ascending loop of Henle and inhibit the Na-K-Cl cotransporter. This blocks the reabsorption of sodium and chloride and results in salt-water excretion. This relieves congestion and reduces oedema.
Other diuretics act on the following part of the nephron:
1. Thiazide diuretics – Na/Cl co-transporter in the distal convoluted tubule
2. Osmotic diuretics – PCT and the loop of Henle
3. Aldosterone antagonists – distal convoluted tubule
4. Carbonic anhydrase inhibitors – inhibit the carbonic anhydrase and act on proximal tubular cells -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 60
Incorrect
-
Regarding the resting membrane potential, which of the following statements is CORRECT:
Your Answer: A neurone has a resting membrane potential of about -90 mV.
Correct Answer: The resting cell membrane is more permeable to K + ions than to Na + ions.
Explanation:A membrane potential is a property of all cell membranes, but the ability to generate an action potential is only a property of excitable tissues. The resting membrane is more permeable to K+and Cl-than to other ions (and relatively impermeable to Na+); therefore the resting membrane potential is primarily determined by the K+equilibrium potential. At rest the inside of the cell is negative relative to the outside. In most neurones the resting potential has a value of approximately -70 mV.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 61
Incorrect
-
Hartmann's solution contains how much sodium:
Your Answer: 94 mmol/L
Correct Answer: 131 mmol/L
Explanation:Hartmann’s solution (compound sodium lactate) contains: Na+131 mmol/L, K+5 mmol/L, HCO3-29 mmol/L (as lactate), Cl-111 mmol/L, Ca2+2 mmol/L. It can be used instead of isotonic sodium chloride solution during or after surgery, or in the initial management of the injured or wounded; it may reduce the risk of hyperchloraemic acidosis.
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This question is part of the following fields:
- Fluids And Electrolytes
- Pharmacology
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Question 62
Correct
-
A 33-year-old woman demonstrates right-sided superior homonymous quadrantanopia upon visual field testing. A diagnosis of a brain tumour has been established.
Which of the following anatomical points in the visual pathway has the lesion occurred?Your Answer: Lower optic radiation
Explanation:Homonymous quadrantanopia is not a disease; it is a clinical finding that points towards a lesion of the optic radiations coursing through the temporal lobe.
Homonymous superior quadrantanopia is caused by damage to the contralateral inferior parts of the posterior visual pathway: the inferior optic radiation (temporal Meyer loop), or the inferior part of the occipital visual cortex below the calcarine fissure. -
This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 63
Incorrect
-
Your consultant requests that you do a lumbar puncture on a patient who is suspected of having meningitis. This patient, a 15-year-old female, presented to the emergency department with a fever, headache, and neck stiffness. Where should you aspirate a sample of CSF?
Your Answer: Space between the dura mater and the spinal canal
Correct Answer: Subarachnoid space
Explanation:A lumbar puncture, also known as a spinal tap, is a procedure that involves inserting a needle into the lower back’s lumbar region.
A needle is inserted into the space between the arachnoid mater and the pia mater, also known as the subarachnoid space, to remove a sample of cerebrospinal fluid.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 64
Incorrect
-
A 45-old woman is on several medications and being treated for epilepsy and bipolar disorder. In the ward rounds, you are asked to examine her in detail and discover she has a noticeable tremor. You believe that one of her medications may be responsible for this new onset tremor.
Which of the following medications is least likely to be responsible for this tremor?Your Answer:
Correct Answer: Carbamazepine
Explanation:The only medication that does not commonly cause tremors is carbamazepine.
The other drugs present with the following types of tremors as a side effect to their usage:
1. Sodium valproate – Postural tremor is most common, but a resting tremor can also occur. Approximately 25% of patients taking sodium valproate are found to develop a tremor within 12 months of starting therapy.
2. Lithium – fine hand tremor is very commonly seen and reported in as many as 50% of patients during the first week of therapy. The tremor tends to reduce with time and is only present in around 5% of patients taking the medication two years or longer.
3. Atypical antipsychotics, such as olanzapine and quetiapine – tremor and limb shakiness. -
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 65
Incorrect
-
A 23-year-old has a known diagnosis of HIV. Blood is sent to the laboratory for tests.
AIDS be diagnosed at a CD4 counts below?Your Answer:
Correct Answer: 200 cells/mm 3
Explanation:A normal CD4 count ranges from 500-1000 cells/mm3.
At CD4 count of less than 350 cells/mm3 treatment with anti-retroviral therapy should be considered.
At a CD4 count of >200 cells/mm3 AIDS is diagnosed.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 66
Incorrect
-
You contact the intensive care outreach team to inquire about a severely hypotensive resuscitated patient. They make the decision to start a dopamine infusion.
Dopamine primarily has which of the following effects at high doses (>15 g/kg/min)?Your Answer:
Correct Answer: Alpha-adrenergic stimulation
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.
Because clearance varies greatly in critically ill patients, plasma concentrations cannot be predicted reliably from infusion rates.
Dopamine is given as an intravenous infusion, and because extravasation can cause tissue necrosis and sloughing, a central line is usually used (especially at higher doses >240 g/min). In an emergency, however, dopamine can be administered through a large vein (cephalic or basilic) while a central line is being prepared. Alkaline intravenous solutions inactivate it, so sodium bicarbonate should not be infused with it.The following are the most common dopamine side effects:
Nausea and vomiting
Tachycardia
Dysrhythmias
Angina
Hypertension -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 67
Incorrect
-
Gastrin release from antral G-cells is stimulated by all but which one of the following:
Your Answer:
Correct Answer: Secretin
Explanation:Gastrin secretion is stimulated by:
The presence of small peptides and amino acids in chyme
Gastric distension
Vagal stimulation directly via acetylcholine and indirectly via gastrin-releasing peptide (GRP)
Raised gastric pH -
This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 68
Incorrect
-
The 'pump handle' movement of the thoracic wall describes which of the following movements:
Your Answer:
Correct Answer: The anterior ends of the ribs moving upwards and forwards
Explanation:Because the anterior ends of the ribs are inferior to the posterior ends, when the ribs are elevated, the anterior end moves upwards and forwards, moving the sternum upwards and forwards in turn. This ‘pump handle’ upwards and forwards movement changes the anteroposterior (AP) dimension of the thorax.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 69
Incorrect
-
After an accidental fall, a 75-year-old patient complains of neck pain and weakness in his upper limbs. Select the condition that most likely caused the neck pain and weakness of the upper limbs of the patient.
Your Answer:
Correct Answer: Central cord syndrome
Explanation:The cervical spinal cord is the section of the spinal cord that goes through the bones of the neck.
It is injured incompletely in the central cord syndrome (CCS). This will result in arm weakness more than leg weakness.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 70
Incorrect
-
A young boy is carried by his friends to the Emergency Department in an unconscious state. He is quickly moved into the resuscitation room.
He was at a party with friends and has injected heroin. On examination, his GCS is 6/15, and he has bilateral pinpoint pupils and a very low respiratory rate of 6 breaths per minute.
Which of the following is the first-line treatment for this patient?Your Answer:
Correct Answer: Naloxone 0.8 mg IV
Explanation:Heroin is injected into the veins and is the most commonly abused drug. Acute intoxication with opioid overuse is the most common cause of death by drug overdose.
The clinical features of opioid overdose are:
1. Decreased respiratory rate
2. Reduced conscious level or coma
3. Decreased bowel sounds
4. Miotic (constricted) pupils
5. Cyanosis
6. Hypotension
7. Seizures
8. Non-cardiogenic pulmonary oedema (with IV heroin usage)The main cause of death secondary to opioid overdose is respiratory depression, which usually occurs within 1 hour of the overdose. Vomiting is also common, and aspiration can occur.
Naloxone is a short-acting, specific antagonist of mu(μ)-opioid receptors. It is used to reverse the effects of opioid toxicity.
It can be given by a continuous infusion if repeated doses are required and the infusion rate is adjusted according to the vital signs. Initially, the infusion rate can be set at 60% of the initial resuscitative IV dose per hour.
Naloxone has a shorter duration of action (6-24 hours) than most opioids, and so close monitoring according to the respiratory rate and depth of coma with repeated injections is necessary. When repeated doses are needed in opioid addicts, naloxone administration may precipitate a withdrawal syndrome with abdominal cramps, nausea and diarrhoea, but these usually settle within 2 hours.
An initial dose of 0.4 to 2 mg can be given intravenously and can be repeated at 2 to 3-minute intervals to a maximum of 10mg.
If the intravenous route is inaccessible, naloxone can be administered via an IO line, subcutaneously (SQ), IM, or via the intranasal (IN) route.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 71
Incorrect
-
Regarding Campylobacter gastroenteritis, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: Infection usually requires antibiotic treatment.
Explanation:Campylobacter jejuni is the primary human pathogen, typically causing dysentery (bloody diarrhoea illness) following ingestion of contaminated meat, especially poultry. Infection is typically self-limiting and does not require antibiotic therapy. Campylobacter gastroenteritis is associated with the immune-mediated complications of Guillain-Barre syndrome, reactive arthritis and Reiter’s syndrome.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 72
Incorrect
-
All of the statements regarding vascular tone are correct except:
Your Answer:
Correct Answer: Most endogenous vasodilators act by decreasing levels of cAMP or cGMP.
Explanation:Most vasoconstrictors bind to G-protein coupled receptors. These mediate elevation in intracellular [Ca2+] which leads to vascular smooth muscle contraction. Important vasoconstrictors include noradrenaline, endothelin-1 and angiotensin II.
Increased intracellular Ca2+ is as a result of the release of Ca2+from the sarcoplasmic reticulum and depolarisation and entry of Ca2+via L-type voltage-gated Ca2+channels. Most types of vascular smooth muscle do not generate action potentials – instead, the depolarisation is graded, which allows graded entry of Ca2+.
sequestration by the sarcoplasmic reticulum Ca2+ATPase, removal from the cell by a plasma membrane Ca2+ATPase and Na+/Ca2+exchange decreases intracellular Ca2+, resulting in vasodilation. Relaxation is a result of most endogenous vasodilators when there is an increase in cyclic guanosine monophosphate (cGMP) like nitric oxide) or cyclic adenosine monophosphate (cAMP) like prostacyclin and beta-adrenergic receptor agonists. These activate protein kinases causing substrate level phosphorylation.
Clinically effective vasodilators are L-type Ca2+channel blocker drugs. -
This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 73
Incorrect
-
Which of the following side effects would you least associated with ciprofloxacin:
Your Answer:
Correct Answer: Folate deficiency
Explanation:Common side effects include diarrhoea, dizziness, headache, nausea and vomiting.
Other adverse effects include: Tendon damage (including rupture), Seizures (in patients with and without epilepsy), QT-interval prolongation, Photosensitivity and Antibiotic-associated colitis -
This question is part of the following fields:
- Infections
- Pharmacology
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Question 74
Incorrect
-
Regarding loop diuretics, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: The risk of hypokalaemia is greater with loop diuretics than with an equipotent dose of a thiazide diuretic.
Explanation:Hypokalaemia can occur with both thiazide and loop diuretics. The risk of hypokalaemia depends on the duration of action as well as the potency and is thus greater with thiazides than with an equipotent dose of a loop diuretic. Hypokalaemia is dangerous in severe cardiovascular disease and in patients also being treated with cardiac glycosides. Often the use of potassium-sparing diuretics avoids the need to take potassium supplements. In hepatic failure, hypokalaemia caused by diuretics can precipitate encephalopathy, particularly in alcoholic cirrhosis.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 75
Incorrect
-
The sensory innervation of the oropharynx is provided by which of the following nerves:
Your Answer:
Correct Answer: Glossopharyngeal nerve
Explanation:Each subdivision of the pharynx has a different sensory innervation:the nasopharynx is innervated by the maxillary nervethe oropharynx is innervated by the glossopharyngeal nervethe laryngopharynx is innervated by the vagus nerve.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 76
Incorrect
-
A 70-year-old man has severe diarrhoea one week after taking co-amoxiclav for a chest infection. The diarrhoea is yellow in colour and smell is offensive.
What is the SINGLE MOST likely causative organism?
Your Answer:
Correct Answer: Clostridium difficile
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.
About 80% of Clostridium difficile infections are seen in people over the age of 65 and its main clinical features are:
Abdominal cramps, severe bloody and/or watery diarrhoea, offensive smelling diarrhoea, and fever. -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 77
Incorrect
-
Which of the following features of cell damage tends to be reversible:
Your Answer:
Correct Answer: Swelling of endoplasmic reticulum and some mitochondria
Explanation:Features of cell damage that tend to be reversible include: swelling of endoplasmic reticulum and some mitochondrialoss of ribosomescell stress response
Features of cell damage that tend to be irreversible include: loss of nucleolus, no ribosomes, swelling of all mitochondria, nuclear condensation, membrane blebs and holes, lysosome rupture, fragmentation of all inner membranes, nuclear breakup -
This question is part of the following fields:
- Inflammatory Responses
- Pathology
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Question 78
Incorrect
-
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 79
Incorrect
-
Which of the following body location is the appropriate site to apply pressure when performing a carotid sinus massage?
Your Answer:
Correct Answer: Thyroid cartilage
Explanation:The common carotid artery runs through the neck and divides into internal and external carotid arteries on both sides near the upper thyroid cartilage. In emergency situations, carotid sinus massage is also used to diagnose or treat paroxysmal supraventricular tachycardia.
During the procedure, to maximize access to the carotid artery, the patient is put in a supine position with the neck extended (i.e. elevating the chin away from the chest). The carotid sinus is normally positioned inferior to the angle of the jaw, near the arterial impulse, at the level of the thyroid cartilage. For 5 to 10 seconds, pressure is administered to one carotid sinus.
Although pulsatile pressure applied in a vigorous circular motion may be more effective, continuous pressure is preferred since it is more reproducible. If the predicted reaction is not obtained, the operation is repeated on the opposite side after a one- to two-minute wait.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 80
Incorrect
-
A 57-year-old woman receives vitamin B12 injections following a gastrectomy.
Which of the following cell types, if absent, is responsible for her vitamin B12 deficiency?Your Answer:
Correct Answer: Parietal cells
Explanation:Intrinsic factor, produced by the parietal cells of the stomach, is essential for the absorption of vitamin B12 from the terminal ileum.
After a gastrectomy, the absorption of vitamin B12 is markedly reduced, and a deficiency will occur. -
This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 81
Incorrect
-
A 24-year-old male presents to the Emergency Department with a three-day history of high-grade fever, headache and rash along with neck stiffness. On examination, Kernig's sign is positive, and you note a petechial rash over the trunk and limbs. Her vital signs show tachycardia and hypotension. Based on these findings, you diagnose sepsis secondary to meningitis.
Which one of the following definitions of sepsis is currently accepted?Your Answer:
Correct Answer: Life-threatening organ dysfunction caused by a dysregulated host response to infection
Explanation:In 2016 the SOFA guideline was introduced, also called the Sepsis-related Organ Failure Assessment, to make a sepsis diagnosis easier and prevent mortality.
According to this guideline, sepsis was defined as a life-threatening organ dysfunction due to a dysregulated host response to infection.
Septic shock was defined as a subset of sepsis in which the circulatory and metabolic abnormalities would lead to a greater risk of mortality than sepsis alone. Patients with septic shock would be clinically identified by a need for vasopressors to maintain MAP greater than 65 mmHg and serum lactate greater than two mmol/L.
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This question is part of the following fields:
- Pathology
- Pathology Of Infections
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Question 82
Incorrect
-
You examine a 72-year-old man who has recently begun bumetanide treatment for worsening heart failure.
Which of these statements about bumetanide is correct?Your Answer:
Correct Answer: It has better intestinal absorption than furosemide
Explanation:Bumetanide is a loop diuretic that is used to treat congestive heart failure. It is frequently used in patients who have failed to respond to high doses of furosemide.
It has a potency of about 40 times that of furosemide, with a 1 mg dose being roughly equivalent to a 40 mg dose of furosemide.
Seizures are not known to be triggered by bumetanide. In fact, it lowers the concentration of neuronal chloride, making GABA’s action more depolarizing, and it’s currently being tested as an antiepileptic in the neonatal period.It takes effect after 1 hour of oral administration, and diuresis takes 6 hours to complete.
Bumetanide absorbs much better in the intestine than furosemide. Because it has a higher bioavailability than furosemide, it is commonly used in patients with gut oedema.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 83
Incorrect
-
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:
Correct 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 84
Incorrect
-
Which of the following cervical nerves is likely to be affected if your patient is complaining of elbow extension weakness and loss of sensation in her middle finger? She also has pain and tenderness in her cervical region, which is caused by a herniated disc, all after a whiplash-type injury in a car accident.
Your Answer:
Correct Answer: C7
Explanation:A C7 spinal nerve controls elbow extension and some finger extension.
Damage to this nerve can result in a burning pain in the shoulder blade or back of the arms. The ability to extend shoulders, arms, and fingers may also be affected. Dexterity may also be compromised in the hands or fingers.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 85
Incorrect
-
The following are all examples of type III hypersensitivity EXCEPT for:
Your Answer:
Correct Answer: Goodpasture's syndrome
Explanation:Examples of type III reactions include:
Extrinsic allergic alveolitis
Systemic lupus erythematosus (SLE)
Post-streptococcal glomerulonephritis
Reactive arthritis
Rheumatoid arthritis -
This question is part of the following fields:
- Immune Responses
- Pathology
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Question 86
Incorrect
-
A 32 year old man is brought to ED having been thrown off his motorbike. Following initial resuscitation and ruling out life-threatening injuries, you establish the patient has weakness of hip flexion. Which of the following nerves has most likely been injured:
Your Answer:
Correct Answer: Femoral nerve
Explanation:Flexion of the hip is produced by the iliacus, the psoas major, the sartorius, rectus femoris and the pectineus muscles. The femoral nerve innervates the iliacus, pectineus, sartorius and quadriceps femoris muscles, and supplies skin on the anterior thigh, anteromedial knee and medial leg.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 87
Incorrect
-
A 76-year-old man presents with complaints of double vision. Upon physical examination, it was observed that he exhibits left-sided hemiplegia and left-sided loss of joint position sense, vibratory sense and discriminatory touch. In addition, he has the inability to abduct his right eye and is holding his head towards the right side. A CT scan was ordered and showed that he has suffered a right-sided stroke.
Branches of which of the following arteries are most likely implicated in the case?Your Answer:
Correct Answer: Basilar artery
Explanation:Inferior medial pontine syndrome, also known as Foville syndrome, is one of the brainstem stroke syndromes which occurs when there is infarction of the medial inferior aspect of the pons due to occlusion of the paramedian branches of the basilar artery.
It is characterized by ipsilateral sixth nerve palsy, facial palsy, contralateral hemiparesis, contralateral loss of proprioception and vibration, ipsilateral ataxia, ipsilateral facial weakness, and lateral gaze paralysis and diplopia.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 88
Incorrect
-
A 26-year-old athlete presents with buttock pain after tearing his gluteus maximus muscle.
Which of the following is NOT an action of the gluteus maximus muscle? Select ONE answer only.Your Answer:
Correct Answer: Hip abduction
Explanation:Gluteus maximus is the main extensor muscle of the hip and assists with lateral rotation of the thigh at the hip joint. It also acts as a hip adductor, steadies the thigh, and assists in raising the trunk from a flexed position.
Gluteus maximus is innervated by the inferior gluteal nerve. -
This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 89
Incorrect
-
A patient presents with increased breathlessness and worsening of his chronic cough and. He has a chronic lung disorder and is on long-term oxygen therapy (LTOT). Which of these is an indication for LTOT?
Your Answer:
Correct Answer: A non-smoker with COPD and a PaO2 of 7.5 kPa when stable with secondary polycythaemia
Explanation:Long-term administration of oxygen, usually at least 15 hours daily, improves survival in COPD patients who have severe hypoxaemia.
Long-term oxygen therapy should be considered in:
A non-smoker with COPD and a PaO2<7.3 kPa when stable
A non-smoker with COPD and PaO27.3–8 kPa when stable and with secondary polycythaemia, peripheral oedema, or evidence of pulmonary hypertension
Severe chronic asthma with PaO2<7.3 kPa or persistent disabling breathlessness
A patient with Interstitial lung disease with PaO2<8 kPa and in patients with PaO2>8 kPa with disabling dyspnoea
A patient with cystic fibrosis when PaO2<7.3 kPa or if PaO27.3–8 kPa in the presence of secondary polycythaemia, nocturnal hypoxaemia, pulmonary hypertension, or peripheral oedema
Pulmonary hypertension, without parenchymal lung involvement when PaO2<8 kPa
Neuromuscular or skeletal disorders, after specialist assessment
Obstructive sleep apnoea despite continuous positive airways pressure therapy, after specialist assessment
Pulmonary malignancy or other terminal disease with disabling dyspnoea
Heart failure with daytime PaO2<7.3 kPa when breathing air or with nocturnal hypoxaemia
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This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 90
Incorrect
-
Regarding hypernatraemia, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: In acute severe hypernatraemia, seizures and intracranial vascular haemorrhage can occur as a result of brain cell lysis.
Explanation:Acute severe hypernatraemia is a medical emergency and requires inpatient management in a high dependency setting. Seizures and intracranial vascular haemorrhage as a result of brain cell crenation can occur. The cause is most commonly excessive water loss and the key aspect of treatment is aggressive fluid replacement (typically with normal saline as this is relatively hypotonic). If urine osmolality is low, diabetes insipidus (DI )should be considered and a trial of synthetic ADH given. In patients with known DI, it is essential to ensure synthetic ADH is given parenterally and that close fluid balance is observed.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 91
Incorrect
-
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:
Correct 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-uptake
Breakdown
DiffusionSerotonin 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. -
This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 92
Incorrect
-
A 32-year old male patient has been diagnosed with meningococcal meningitis and was given appropriate treatments. Because he is a family man, he fears that he might transmit the infection to the rest of his family members.
The causative agent of meningococcal meningitis is spread via what mode of transmission?Your Answer:
Correct Answer: Respiratory droplet route
Explanation:N. meningitidis, the causative agent of meningococcal meningitis, is considered both a commensal and a pathogen. It can be found in the surfaces of mucous membranes such as the nasopharynx and oropharynx. With this, it can be transmitted from a carrier to a new host via respiratory droplet secretions.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 93
Incorrect
-
A 32-year-old woman with a history of bipolar disorder exhibits lithium toxicity symptoms.
Which of the following is the MOST LIKELY feature to be present?Your Answer:
Correct Answer: Clonus
Explanation:Lithium toxicity manifests itself in the following ways:
Ataxia
Clonus
Coma
Confusion
Convulsions
Diarrhoea
Increased muscle tone
Nausea and vomiting
Nephrogenic diabetes insipidus
Renal failure
Tremor -
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 94
Incorrect
-
A 35-year-old man suffers an open fracture of his forearm. The nerve that innervates the pronator quadratus muscle is damaged as a consequence of this injury.
Which of the following nerves has been damaged in this case? Select ONE answer only.Your Answer:
Correct Answer: The anterior interosseous nerve
Explanation:Pronator quadratus is a small, square-shaped muscle that lies in the anterior compartment of the forearm. It arises from the distal fourth of the anterior surface of the ulna and inserts into the distal fourth of the anterior surface of the radius.
Pronator quadratus is innervated by the anterior interosseous nerve. It receives its blood supply from the anterior interosseous artery, which is a branch of the common interosseous artery, which in turn is a branch of the ulnar artery.
The main action of pronator quadratus is to assist pronator teres with pronation of the forearm. The deep fibres bind the radius and ulna together.
The pronator quadratus muscle highlighted in blue (adapted from Gray’s Anatomy) -
This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 95
Incorrect
-
All of the following predisposes to lithium toxicity in patients taking long-term therapy EXCEPT:
Your Answer:
Correct Answer: Hypernatraemia
Explanation:A common complication of long term lithium therapy results in most cases of lithium intoxication. It is caused by reduced excretion of the drug which can be due to several factors including deterioration of renal function, dehydration, hyponatraemia, infections, and co-administration of diuretics or NSAIDs or other drugs that may interact.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 96
Incorrect
-
By what mechanism does Vibrio cholerae causes diarrhoea?
Your Answer:
Correct Answer: Increases Cl- secretory channels in crypt cells
Explanation:Cholera is a severe diarrheal illness caused by the Vibrio cholerae bacteria infecting the bowel. Ingesting cholera-infected food or drink is the a way to contract the disease. In the intestinal crypt cells, the toxigenic bacterium Vibrio cholera activates adenylate cyclase and raises cyclic adenosine monophosphate (cAMP).
cAMP stimulates the Cl-secretory channels in crypt cells, resulting in the secretion of chloride with sodium ions and water. The toxin it produces causes the body to secrete massive amounts of water, resulting in diarrhoea and significant fluid and electrolyte loss.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 97
Incorrect
-
Which of these is an example of ordinal data?
Your Answer:
Correct Answer: Disease staging system
Explanation:Categorical data or data that is ordered is Ordinal data e.g. disease staging system, pain scoring system.
Disease staging system is the correct answer
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This question is part of the following fields:
- Evidence Based Medicine
- Statistics
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Question 98
Incorrect
-
Regarding co-amoxiclav, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: Clavulanic acid acts to inhibit cross-linking of bacterial peptidoglycan polymers.
Explanation:Co-amoxiclav consists of amoxicillin with the beta-lactamase inhibitor clavulanic acid. Clavulanic acid itself has no significant antibacterial activity but, by inactivating beta-lactamases, it makes the combination active against beta-lactamase-producing bacteria that are resistant to amoxicillin.The most common adverse effects of co-amoxiclav include nausea, vomiting, skin rash and diarrhoea. Pseudomembranous colitis should be considered if a person develops severe diarrhoea during or after treatment with co-amoxiclav. Cholestatic jaundice can occur either during or shortly after the use of co-amoxiclav. An epidemiological study has shown that the risk of acute liver toxicity was about 6 times greater with co-amoxiclav than with amoxicillin. Cholestatic jaundice is more common in patients above the age of 65 years and in men; these reactions have only rarely been reported in children. Jaundice is usually self-limiting and very rarely fatal.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 99
Incorrect
-
You evaluate a 80-year-old man who has a history of persistent heart failure and discover that he has generalised oedema.
Which of the following claims regarding capillary hydrostatic pressure (P c) is false?Your Answer:
Correct Answer: P c increases along the length of the capillary, from arteriole to venule
Explanation:The capillary hydrostatic pressure (Pc) is normally between 15 and 30 millimetres of mercury. Pc Decreases along the capillary’s length, mirroring the arteriolar and venule pressures proximally and distally.
Pc is determined by the ratio of arteriolar resistance (RA) to venular resistance (RV).When the RA/RV ratio is high, the pressure drop across the capillary is modest, and Pcis is close to venule pressure.
When the ratio of RA/RV is low, the pressure drop across the capillary is considerable, and Pcis is close to arteriolar pressure.
Pcis closer to the venule pressure and thus more responsive to changes in venous pressure than arteriolar pressure when RA/RV is high.
Pcis the major force behind fluid pushing out of the capillary bed and into the interstitium.
It is also the most variable of the forces affecting fluid transport at the capillary, partly because sympathetic-mediated arteriolar vasoconstriction varies. -
This question is part of the following fields:
- Cardiovascular Physiology
- Physiology
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Question 100
Incorrect
-
Dexamethasone would be most useful for which of the following conditions:
Your Answer:
Correct Answer: Raised intracranial pressure secondary to malignancy
Explanation:Dexamethasone has a very high glucocorticoid activity in conjunction with insignificant mineralocorticoid activity. This makes it particularly suitable for high-dose therapy in conditions where fluid retention would be a disadvantage such as in the management of raised intracranial pressure or cerebral oedema secondary to malignancy. Dexamethasone also has a long duration of action and this, coupled with its lack of mineralocorticoid action makes it particularly suitable for suppression of corticotropin secretion in congenital adrenal hyperplasia. In most individuals a single dose of dexamethasone at night, is sufficient to inhibit corticotropin secretion for 24 hours. This is the basis of the ‘overnight dexamethasone suppression test’ for diagnosing Cushing’s syndrome.
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This question is part of the following fields:
- Endocrine
- Pharmacology
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SESSION STATS - PERFORMANCE PER SPECIALTY
