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Question 1
Incorrect
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A 13-year-old boy comes to the clinic with his mother complaining of ear pain. He experienced the pain last night and was unable to sleep. As a result, he stayed home from school today. He reports that sounds are muffled on the affected side. During the examination, he has a fever. Otoscopy reveals a bulging tympanic membrane with visible fluid level, indicating a middle ear infection. The nerve to tensor tympani arises from which nerve?
Your Answer: Vestibulocochlear nerve
Correct Answer: Mandibular nerve
Explanation:The mandibular nerve is the correct answer. It is the only division of the trigeminal nerve that carries motor fibers. The vestibulocochlear nerve is the eighth cranial nerve and has two components for balance and hearing. The glossopharyngeal nerve is the ninth cranial nerve and has various functions, including taste and sensation from the tongue, pharyngeal wall, and tonsils. The maxillary nerve carries only sensory fibers. The facial nerve is the seventh cranial nerve and supplies the muscles of facial expression and taste from the anterior two-thirds of the tongue. Tensor tympani is a muscle that dampens loud noises and is innervated through the nerve to tensor tympani, which arises from the mandibular nerve. The patient’s ear pain is likely due to otitis media, which is confirmed on otoscopy.
The trigeminal nerve is the main sensory nerve of the head and also innervates the muscles of mastication. It has sensory distribution to the scalp, face, oral cavity, nose and sinuses, and dura mater, and motor distribution to the muscles of mastication, mylohyoid, anterior belly of digastric, tensor tympani, and tensor palati. The nerve originates at the pons and has three branches: ophthalmic, maxillary, and mandibular. The ophthalmic and maxillary branches are sensory only, while the mandibular branch is both sensory and motor. The nerve innervates various muscles, including the masseter, temporalis, and pterygoids.
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This question is part of the following fields:
- Neurological System
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Question 2
Incorrect
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What is the mechanism of action of amiloride for elderly patients?
Your Answer: Inhibits the Na-K-Cl cotransporter in the thick ascending limb of the loop of Henle
Correct Answer: Blocks the epithelial sodium channel in the distal convoluted tubule
Explanation:Potassium-sparing diuretics are classified into two types: epithelial sodium channel blockers (such as amiloride and triamterene) and aldosterone antagonists (such as spironolactone and eplerenone). However, caution should be exercised when using these drugs in patients taking ACE inhibitors as they can cause hyperkalaemia. Amiloride is a weak diuretic that blocks the epithelial sodium channel in the distal convoluted tubule. It is usually given with thiazides or loop diuretics as an alternative to potassium supplementation since these drugs often cause hypokalaemia. On the other hand, aldosterone antagonists like spironolactone act in the cortical collecting duct and are used to treat conditions such as ascites, heart failure, nephrotic syndrome, and Conn’s syndrome. In patients with cirrhosis, relatively large doses of spironolactone (100 or 200 mg) are often used to manage secondary hyperaldosteronism.
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This question is part of the following fields:
- General Principles
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Question 3
Incorrect
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An 78-year-old man with a history of hypertension, ischaemic heart disease and peripheral vascular disease presents with palpitations and syncope. His ECG reveals an irregularly irregular pulse of 124 beats/min. What factor in his medical history will be given the most consideration when deciding whether or not to administer anticoagulation?
Your Answer: Syncope
Correct Answer: Age
Explanation:To determine the need for anticoagulation in patients with atrial fibrillation, it is necessary to conduct a CHA2DS2-VASc score assessment. This involves considering various factors, including age (which is weighted heaviest, with 2 points given for those aged 75 and over), hypertension (1 point), and congestive heart disease (1 point). Palpitations, however, are not included in the CHA2DS2-VASc tool.
Atrial fibrillation (AF) is a condition that requires careful management, including the use of anticoagulation therapy. The latest guidelines from NICE recommend assessing the need for anticoagulation in all patients with a history of AF, regardless of whether they are currently experiencing symptoms. The CHA2DS2-VASc scoring system is used to determine the most appropriate anticoagulation strategy, with a score of 2 or more indicating the need for anticoagulation. However, it is important to ensure a transthoracic echocardiogram has been done to exclude valvular heart disease, which is an absolute indication for anticoagulation.
When considering anticoagulation therapy, doctors must also assess the patient’s bleeding risk. NICE recommends using the ORBIT scoring system to formalize this risk assessment, taking into account factors such as haemoglobin levels, age, bleeding history, renal impairment, and treatment with antiplatelet agents. While there are no formal rules on how to act on the ORBIT score, individual patient factors should be considered. The risk of bleeding increases with a higher ORBIT score, with a score of 4-7 indicating a high risk of bleeding.
For many years, warfarin was the anticoagulant of choice for AF. However, the development of direct oral anticoagulants (DOACs) has changed this. DOACs have the advantage of not requiring regular blood tests to check the INR and are now recommended as the first-line anticoagulant for patients with AF. The recommended DOACs for reducing stroke risk in AF are apixaban, dabigatran, edoxaban, and rivaroxaban. Warfarin is now used second-line, in patients where a DOAC is contraindicated or not tolerated. Aspirin is not recommended for reducing stroke risk in patients with AF.
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This question is part of the following fields:
- Cardiovascular System
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Question 4
Incorrect
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A 23-year-old man acquires an infection in the pulp of his pinky finger. What is the closest location to which this infection can spread?
Your Answer: The distal interphalangeal joint
Correct Answer: Proximal to the flexor retinaculum
Explanation:The tendon sheath that runs from the little finger to the proximal part of the carpal tunnel poses a considerable risk of facilitating the spread of infections towards the proximal direction.
Anatomy of the Hand: Fascia, Compartments, and Tendons
The hand is composed of bones, muscles, and tendons that work together to perform various functions. The bones of the hand include eight carpal bones, five metacarpals, and 14 phalanges. The intrinsic muscles of the hand include the interossei, which are supplied by the ulnar nerve, and the lumbricals, which flex the metacarpophalangeal joints and extend the interphalangeal joint. The thenar eminence contains the abductor pollicis brevis, opponens pollicis, and flexor pollicis brevis, while the hypothenar eminence contains the opponens digiti minimi, flexor digiti minimi brevis, and abductor digiti minimi.
The fascia of the palm is thin over the thenar and hypothenar eminences but relatively thick elsewhere. The palmar aponeurosis covers the soft tissues and overlies the flexor tendons. The palmar fascia is continuous with the antebrachial fascia and the fascia of the dorsum of the hand. The hand is divided into compartments by fibrous septa, with the thenar compartment lying lateral to the lateral septum, the hypothenar compartment lying medial to the medial septum, and the central compartment containing the flexor tendons and their sheaths, the lumbricals, the superficial palmar arterial arch, and the digital vessels and nerves. The deepest muscular plane is the adductor compartment, which contains adductor pollicis.
The tendons of the flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) enter the common flexor sheath deep to the flexor retinaculum. The tendons enter the central compartment of the hand and fan out to their respective digital synovial sheaths. The fibrous digital sheaths contain the flexor tendons and their synovial sheaths, extending from the heads of the metacarpals to the base of the distal phalanges.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 5
Incorrect
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A 50-year-old male is brought to the trauma unit following a car accident, with an estimated blood loss of 1200ml. His vital signs are as follows: heart rate of 125 beats per minute, blood pressure of 125/100 mmHg, and he feels cold to the touch.
Which component of his cardiovascular system has played the biggest role in maintaining his blood pressure stability?Your Answer:
Correct Answer: Arterioles
Explanation:The highest resistance in the cardiovascular system is found in the arterioles, which means they contribute the most to the total peripheral resistance. In cases of compensated hypovolaemic shock, such as in this relatively young patient, the body compensates by increasing heart rate and causing peripheral vasoconstriction to maintain blood pressure.
Arteriole vasoconstriction in hypovolaemic shock patients leads to an increase in total peripheral resistance, which in turn increases mean arterial blood pressure. This has a greater effect on diastolic blood pressure, resulting in a narrowing of pulse pressure and clinical symptoms such as cold peripheries and delayed capillary refill time.
Capillaries are microscopic channels that provide blood supply to the tissues and are the primary site for gas and nutrient exchange. Venules, on the other hand, are small veins with diameters ranging from 8-100 micrometers and join multiple capillaries exiting from a capillary bed.
The heart has four chambers and generates pressures of 0-25 mmHg on the right side and 0-120 mmHg on the left. The cardiac output is the product of heart rate and stroke volume, typically 5-6L per minute. The cardiac impulse is generated in the sino atrial node and conveyed to the ventricles via the atrioventricular node. Parasympathetic and sympathetic fibers project to the heart via the vagus and release acetylcholine and noradrenaline, respectively. The cardiac cycle includes mid diastole, late diastole, early systole, late systole, and early diastole. Preload is the end diastolic volume and afterload is the aortic pressure. Laplace’s law explains the rise in ventricular pressure during the ejection phase and why a dilated diseased heart will have impaired systolic function. Starling’s law states that an increase in end-diastolic volume will produce a larger stroke volume up to a point beyond which stroke volume will fall. Baroreceptor reflexes and atrial stretch receptors are involved in regulating cardiac output.
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This question is part of the following fields:
- Cardiovascular System
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Question 6
Incorrect
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A 67-year-old female presents to a medical facility with a chief complaint of tremors. Upon examination, the physician observes that the tremors are most noticeable when the patient is at rest. The patient does not display any specific neurological deficits, but does exhibit arm rigidity throughout the full range of motion and takes some time to initiate movements. Given the probable diagnosis, what histological finding would be anticipated?
Your Answer:
Correct Answer: Lewy bodies
Explanation:When a patient presents with tremor, rigidity, and bradykinesia, Parkinson’s Disease should be considered as a possible diagnosis. The presence of Lewy Bodies, which are clumps of proteins within neurons, is a characteristic histological finding. These bodies are often found in the substantia nigra and have a cytoplasm that is rich in eosin.
In males with Klinefelter syndrome, Barr bodies, which are inactivated X chromosomes, may be observed.
Cholesterol clefts are a result of cholesterol emboli, which occur when material from an atherosclerotic plaque becomes dislodged and deposited elsewhere. This can happen during procedures such as angiography.
Keratin pearls are a feature of squamous cell lung cancer, where squamous cells form concentric layers around keratin.
The term kidney bean-shaped nuclei refers to the appearance of neutrophils.
Parkinson’s disease is a progressive neurodegenerative disorder that occurs due to the degeneration of dopaminergic neurons in the substantia nigra. This leads to a classic triad of symptoms, including bradykinesia, tremor, and rigidity, which are typically asymmetrical. The disease is more common in men and is usually diagnosed around the age of 65. Bradykinesia is characterized by a poverty of movement, shuffling steps, and difficulty initiating movement. Tremors are most noticeable at rest and typically occur in the thumb and index finger. Rigidity can be either lead pipe or cogwheel, and other features include mask-like facies, flexed posture, and drooling of saliva. Psychiatric features such as depression, dementia, and sleep disturbances may also occur. Diagnosis is usually clinical, but if there is difficulty differentiating between essential tremor and Parkinson’s disease, 123I‑FP‑CIT single photon emission computed tomography (SPECT) may be considered.
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This question is part of the following fields:
- Neurological System
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Question 7
Incorrect
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A 72-year-old man presents to his physician with a gradual yellowing of his skin. During the examination, the physician observes jaundiced sclerae and palpates a round mass under the right costal margin, measuring approximately 4 cm in diameter. The patient's abdomen is soft, non-tender, and not distended.
The physician orders a blood test, which reveals the following results:
- Bilirubin: 180 µmol/L (3 - 17)
- ALP: 98 u/L (30 - 100)
- ALT: 36 u/L (3 - 40)
- γGT: 71 u/L (8 - 60)
- Albumin: 43 g/L (35 - 50)
What clinical sign is evident, and what is the probable diagnosis?Your Answer:
Correct Answer: Courvoisier's sign indicating biliary tract cancer
Explanation:If a patient has painless jaundice and a palpable gallbladder in the right upper quadrant, it is unlikely to be caused by gallstones and more likely to be a malignancy. This is known as Courvoisier’s sign, and the most common cancers associated with it are cholangiocarcinoma and adenocarcinoma of the pancreatic head.
Rovsing’s sign is a sign of acute appendicitis, where palpation of the left lower quadrant causes pain in the right lower quadrant.
Virchow’s sign is the presence of a palpable left supraclavicular lymph node, which is a sign of metastatic gastric cancer.
Understanding Cholangiocarcinoma
Cholangiocarcinoma, also known as bile duct cancer, is a serious medical condition that can be caused by primary sclerosing cholangitis. This disease is characterized by persistent biliary colic symptoms, which can be accompanied by anorexia, jaundice, and weight loss. In some cases, a palpable mass in the right upper quadrant may be present, which is known as the Courvoisier sign. Additionally, periumbilical lymphadenopathy (Sister Mary Joseph nodes) and left supraclavicular adenopathy (Virchow node) may be seen.
One of the main risk factors for cholangiocarcinoma is primary sclerosing cholangitis. This condition can cause inflammation and scarring of the bile ducts, which can lead to the development of cancer over time. To detect cholangiocarcinoma in patients with primary sclerosing cholangitis, doctors often use a blood test to measure CA 19-9 levels.
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This question is part of the following fields:
- Gastrointestinal System
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Question 8
Incorrect
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A 78-year-old woman has recently been diagnosed with heart failure following 10 months of progressive ankle swelling and shortness of breath. She has been prescribed various medications, provided with lifestyle recommendations, and informed about her prognosis. Due to her new diagnosis, what are the two types of valve dysfunction that she is most susceptible to?
Your Answer:
Correct Answer: Mitral regurgitation and tricuspid regurgitation
Explanation:Functional mitral and tricuspid regurgitations are the most frequent valve dysfunctions that occur as a result of heart failure. This is due to the fact that the enlarged ventricles prevent the valves from fully closing during diastole.
Diagnosis of Chronic Heart Failure
Chronic heart failure is a serious condition that requires prompt diagnosis and management. In 2018, the National Institute for Health and Care Excellence (NICE) updated its guidelines on the diagnosis and management of chronic heart failure. According to the new guidelines, all patients should undergo an N-terminal pro-B-type natriuretic peptide (NT‑proBNP) blood test as the first-line investigation, regardless of whether they have previously had a myocardial infarction or not.
Interpreting the NT-proBNP test is crucial in determining the severity of the condition. If the levels are high, specialist assessment, including transthoracic echocardiography, should be arranged within two weeks. If the levels are raised, specialist assessment, including echocardiogram, should be arranged within six weeks.
BNP is a hormone produced mainly by the left ventricular myocardium in response to strain. Very high levels of BNP are associated with a poor prognosis. The table above shows the different levels of BNP and NTproBNP and their corresponding interpretations.
It is important to note that certain factors can alter the BNP level. For instance, left ventricular hypertrophy, ischaemia, tachycardia, and right ventricular overload can increase BNP levels, while diuretics, ACE inhibitors, beta-blockers, angiotensin 2 receptor blockers, and aldosterone antagonists can decrease BNP levels. Therefore, it is crucial to consider these factors when interpreting the NT-proBNP test.
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This question is part of the following fields:
- Cardiovascular System
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Question 9
Incorrect
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A 67-year-old man presents to the emergency department with vomiting blood. The medical team suspects bleeding oesophageal varices and prescribes terlipressin. The patient has a history of alcohol abuse and examination reveals ascites.
Why was terlipressin prescribed in this case?Your Answer:
Correct Answer: Vasoconstriction of splanchnic vessels
Explanation:Terlipressin works by constricting the splanchnic vessels, which increases systemic vascular resistance and promotes renal fluid reabsorption. This leads to an increase in arterial pressure and helps to treat hypovolaemic hypotension. Terlipressin also has a sympathetic stimulating effect and is an analogue of vasopressin.
Variceal haemorrhage is a serious condition that requires prompt and effective management. The initial treatment involves resuscitation of the patient, correction of clotting abnormalities, and administration of vasoactive agents such as terlipressin or octreotide. Prophylactic IV antibiotics are also recommended to reduce mortality in patients with liver cirrhosis. Endoscopic variceal band ligation is the preferred method for controlling bleeding, and the use of a Sengstaken-Blakemore tube or Transjugular Intrahepatic Portosystemic Shunt (TIPSS) may be necessary if bleeding cannot be controlled. However, TIPSS can lead to exacerbation of hepatic encephalopathy, which is a common complication.
To prevent variceal haemorrhage, prophylactic measures such as propranolol and endoscopic variceal band ligation (EVL) are recommended. Propranolol has been shown to reduce rebleeding and mortality compared to placebo. EVL is superior to endoscopic sclerotherapy and should be performed at two-weekly intervals until all varices have been eradicated. Proton pump inhibitor cover is given to prevent EVL-induced ulceration. NICE guidelines recommend offering endoscopic variceal band ligation for the primary prevention of bleeding for people with cirrhosis who have medium to large oesophageal varices.
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This question is part of the following fields:
- Gastrointestinal System
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Question 10
Incorrect
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A 68-year-old woman is referred to haematology via the 2-week wait pathway due to worsening thoracic back pain that started 3 weeks ago. There is no history of trauma. Upon examination, the pain is exacerbated by movement and occurs even at rest and during bedtime. Her blood test results show a Hb level of 97 g/L (female normal range: 115-160 g/L), platelets of 200 * 109/L (normal range: 150-400 * 109/L), and WBC count of 4.0 * 109/L (normal range: 4.0-11.0 * 109/L). Additionally, her calcium level is 2.9 mmol/L (normal range: 2.1-2.6 mmol/L), phosphate level is 1.2 mmol/L (normal range: 0.8-1.4 mmol/L), magnesium level is 0.8 mmol/L (normal range: 0.7-1.0 mmol/L), TSH level is 5.0 mU/L (normal range: 0.5-5.5 mU/L), and free thyroxine (T4) level is 16 pmol/L (normal range: 9.0-18 pmol/L). Based on the likely diagnosis, what is the underlying pathophysiology that causes hypercalcemia?
Your Answer:
Correct Answer: Increased osteoclast activity in response to cytokines
Explanation:Increased osteoclast activity in response to cytokines released by myeloma cells is the primary cause of hypercalcaemia in multiple myeloma, which typically affects individuals aged 60-70 years and presents with bone pain or pathological fractures from osteolytic lesions. Hypercalcaemia in kidney failure is associated with hyperphosphataemia and does not cause bone pain. Elevated calcitriol levels are linked to granulomatous disorders like sarcoidosis and tuberculosis, which do not typically cause bone pain. Rebound hypercalcaemia occurs after rhabdomyolysis, which usually results from a fall and long lie. Although primary hyperparathyroidism is a common cause of hypercalcaemia and can lead to bone pain or pathological fractures, it is not associated with anaemia.
Understanding Multiple Myeloma: Features and Investigations
Multiple myeloma is a type of cancer that affects the plasma cells in the bone marrow. It is most commonly found in patients aged 60-70 years. The disease is characterized by a range of symptoms, which can be remembered using the mnemonic CRABBI. These include hypercalcemia, renal damage, anemia, bleeding, bone lesions, and increased susceptibility to infection. Other features of multiple myeloma include amyloidosis, carpal tunnel syndrome, neuropathy, and hyperviscosity.
To diagnose multiple myeloma, a range of investigations are required. Blood tests can reveal anemia, renal failure, and hypercalcemia. Protein electrophoresis can detect raised levels of monoclonal IgA/IgG proteins in the serum, while bone marrow aspiration can confirm the diagnosis if the number of plasma cells is significantly raised. Imaging studies, such as whole-body MRI or X-rays, can be used to detect osteolytic lesions.
The diagnostic criteria for multiple myeloma require one major and one minor criteria or three minor criteria in an individual who has signs or symptoms of the disease. Major criteria include the presence of plasmacytoma, 30% plasma cells in a bone marrow sample, or elevated levels of M protein in the blood or urine. Minor criteria include 10% to 30% plasma cells in a bone marrow sample, minor elevations in the level of M protein in the blood or urine, osteolytic lesions, or low levels of antibodies in the blood. Understanding the features and investigations of multiple myeloma is crucial for early detection and effective treatment.
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This question is part of the following fields:
- Haematology And Oncology
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Question 11
Incorrect
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A 46-year-old man with a history of hypertrophic cardiomyopathy (HOCM) presents for evaluation at the cardiology clinic. During the assessment, a fourth heart sound is detected.
What characteristic is associated with this clinical observation?Your Answer:
Correct Answer: It coincides with the P wave of the ECG
Explanation:The S4 heart sound occurs simultaneously with the P wave on an ECG. This sound is heard during late diastole when the left ventricle is being actively filled and the atrial contraction is forcing blood into a noncompliant left ventricle. The P wave on the ECG represents the depolarization of the left and right atrium, which results in atrial contraction. Therefore, the S4 heart sound coincides with the P wave on the ECG.
The presence of an S4 heart sound can indicate diastolic heart failure, which is caused by severe left ventricular hypertrophy. This condition can be found in patients with HOCM or can develop as a complication of hypertension or aortic stenosis.
In contrast, the S3 heart sound occurs during early diastole when the left ventricle is being passively filled.
During diastole, the T wave on the ECG represents the repolarization of the ventricles and marks the beginning of ventricular relaxation.
Heart sounds are the sounds produced by the heart during its normal functioning. The first heart sound (S1) is caused by the closure of the mitral and tricuspid valves, while the second heart sound (S2) is due to the closure of the aortic and pulmonary valves. The intensity of these sounds can vary depending on the condition of the valves and the heart. The third heart sound (S3) is caused by the diastolic filling of the ventricle and is considered normal in young individuals. However, it may indicate left ventricular failure, constrictive pericarditis, or mitral regurgitation in older individuals. The fourth heart sound (S4) may be heard in conditions such as aortic stenosis, HOCM, and hypertension, and is caused by atrial contraction against a stiff ventricle. The different valves can be best heard at specific sites on the chest wall, such as the left second intercostal space for the pulmonary valve and the right second intercostal space for the aortic valve.
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This question is part of the following fields:
- Cardiovascular System
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Question 12
Incorrect
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A 45-year-old man with a history of Crohn's disease complains of fatigue and a burning sensation in his mouth. His blood work shows:
Hb 11.2 g/dl
MCV 110 fl
Plt 190 * 10^9/l
WBC 6.2 * 10^9/l
What could be the possible reason for these symptoms and abnormal blood results?Your Answer:
Correct Answer: Vitamin B12 deficiency
Explanation:If a patient has a history of gastrectomy and is experiencing macrocytic anaemia, it is likely that they are suffering from B12 deficiency.
Vitamin B12 is essential for the development of red blood cells and the maintenance of the nervous system. It is absorbed through the binding of intrinsic factor, which is secreted by parietal cells in the stomach, and actively absorbed in the terminal ileum. A deficiency in vitamin B12 can be caused by pernicious anaemia, post gastrectomy, a vegan or poor diet, disorders or surgery of the terminal ileum, Crohn’s disease, or metformin use.
Symptoms of vitamin B12 deficiency include macrocytic anaemia, a sore tongue and mouth, neurological symptoms, and neuropsychiatric symptoms such as mood disturbances. The dorsal column is usually affected first, leading to joint position and vibration issues before distal paraesthesia.
Management of vitamin B12 deficiency involves administering 1 mg of IM hydroxocobalamin three times a week for two weeks, followed by once every three months if there is no neurological involvement. If a patient is also deficient in folic acid, it is important to treat the B12 deficiency first to avoid subacute combined degeneration of the cord.
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This question is part of the following fields:
- Haematology And Oncology
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Question 13
Incorrect
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A 55-year-old man is hospitalized after experiencing haematemesis. Upon examination, his prothrombin time is found to be elevated. What could be a possible reason for this anomaly?
Your Answer:
Correct Answer: Chronic liver disease
Explanation:The inheritance of Haemophilia A and B is crucial in identifying individuals who are at risk of developing the condition. Haemophilia A and B are genetic disorders that are inherited in an X-linked recessive manner. Haemophilia A is caused by a deficiency in clotting factor VIII, while haemophilia B is caused by a deficiency in clotting factor IX.
On the other hand, haemophilia C, which is caused by a deficiency in clotting factor XI, is primarily inherited in an autosomal recessive manner. In X-linked recessive conditions like haemophilia B, males are more likely to be affected than females. This is because males only need one abnormal copy of the gene, which is carried on the X chromosome, to be affected.
Females, on the other hand, can be carriers of the condition if they carry one normal and one abnormal copy of the gene. While carriers can have clotting abnormalities, these are usually milder than those seen in affected individuals. Men cannot pass the condition to their sons, but they will pass on the abnormal X chromosome to all their daughters, who will be carriers.
Female carriers can pass on the condition to around half their sons, and half their daughters will be carriers. Females can only be affected if they are the offspring of an affected male and a carrier female. In summary, the inheritance of haemophilia A and B is crucial in identifying individuals who are at risk of developing the condition. It also helps in providing appropriate genetic counseling and management for affected individuals and their families.
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This question is part of the following fields:
- Haematology And Oncology
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Question 14
Incorrect
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A 6-year-old boy is referred to the child assessment unit for recurrent urinary tract infections. He is started on antibiotics and sent home with advice on supportive care.
Upon his return a week later, his renal function tests have worsened and an ultrasound scan reveals hydronephrosis in his kidneys, ureters, and bladder. The diagnosis is acute pyelonephritis and further investigations are ordered to determine the underlying cause. A voiding cystourethrogram (VCUG) confirms the diagnosis of posterior urethral valves (PUV).
The child and parents are informed of the diagnosis and inquire about treatment options. What is the definitive treatment for PUV?Your Answer:
Correct Answer: Endoscopic valvotomy
Explanation:The preferred and most effective treatment for a child with posterior urethral valves (PUV) is endoscopic valvotomy. While bilateral cutaneous ureterostomies can be used for urinary drainage, they are not considered the definitive treatment for PUV. Bladder augmentation may be necessary if the bladder cannot hold enough urine or if bladder pressures remain high despite medication and catheterization. However, permanent antibiotic prophylaxis and catheterization are not recommended.
Posterior urethral valves are a frequent cause of blockage in the lower urinary tract in males. They can be detected during prenatal ultrasound screenings. Due to the high pressure required for bladder emptying during fetal development, the child may experience damage to the renal parenchyma, resulting in renal impairment in 70% of boys upon diagnosis. Treatment involves the use of a bladder catheter, and endoscopic valvotomy is the preferred definitive treatment. Cystoscopic and renal follow-up is necessary.
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This question is part of the following fields:
- Renal System
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Question 15
Incorrect
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What is the most frequent brain tumour in children?
Your Answer:
Correct Answer: Astrocytoma
Explanation:While astrocytoma is the most prevalent brain tumor in children, glioblastoma multiforme is a rare occurrence. Additionally, medulloblastoma is no longer the primary CNS tumor in children, according to Cancer Research UK.
Understanding CNS Tumours: Types, Diagnosis, and Treatment
CNS tumours can be classified into different types, with glioma and metastatic disease accounting for 60% of cases, followed by meningioma at 20%, and pituitary lesions at 10%. In paediatric practice, medulloblastomas used to be the most common lesions, but astrocytomas now make up the majority. The location of the tumour can affect the onset of symptoms, with those in the speech and visual areas producing early symptoms, while those in the right temporal and frontal lobe may reach considerable size before becoming symptomatic.
Diagnosis of CNS tumours is best done through MRI scanning, which provides the best resolution. Treatment usually involves surgery, even if the tumour cannot be completely resected. Tumour debulking can address conditions such as rising ICP and prolong survival and quality of life. Curative surgery is possible for lesions such as meningiomas, but gliomas have a marked propensity to invade normal brain tissue, making complete resection nearly impossible.
Overall, understanding the types, diagnosis, and treatment of CNS tumours is crucial in managing these conditions and improving patient outcomes. With the right approach, patients can receive timely and effective treatment that addresses their symptoms and improves their quality of life.
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This question is part of the following fields:
- Neurological System
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Question 16
Incorrect
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A 52-year-old woman comes to your GP clinic with a 3 day history of leg pain, fever and nausea. She suspects that a scratch she got from a thorn bush while picking blackberries might have caused it and is worried as the redness seems to be spreading. She has not been immobile recently. Upon further questioning, she mentions having a similar incident a few years ago after a long flight.
During the examination, you observe that the woman is overweight and calculate her body mass index to be 33kg/m². Her vital signs are all within normal limits, except for a temperature of 38.2ºC. The woman's left leg appears to be swollen and red compared to the right. There is a small cluster of scratches in the middle of the lesion.
What is the initial treatment for this condition?Your Answer:
Correct Answer: Flucloxacillin
Explanation:Understanding Cellulitis: Symptoms, Diagnosis, and Treatment
Cellulitis is a common skin infection caused by Streptococcus pyogenes or Staphylococcus aureus. It is characterized by inflammation of the skin and subcutaneous tissues, usually on the shins, accompanied by erythema, pain, swelling, and sometimes fever. The diagnosis of cellulitis is based on clinical features, and no further investigations are required in primary care. However, bloods and blood cultures may be requested if the patient is admitted and septicaemia is suspected.
To guide the management of patients with cellulitis, NICE Clinical Knowledge Summaries recommend using the Eron classification. Patients with Eron Class III or Class IV cellulitis, severe or rapidly deteriorating cellulitis, very young or frail patients, immunocompromised patients, patients with significant lymphoedema, or facial or periorbital cellulitis (unless very mild) should be admitted for intravenous antibiotics. Patients with Eron Class II cellulitis may not require admission if the facilities and expertise are available in the community to give intravenous antibiotics and monitor the patient.
The first-line treatment for mild/moderate cellulitis is flucloxacillin, while clarithromycin, erythromycin (in pregnancy), or doxycycline is recommended for patients allergic to penicillin. Patients with severe cellulitis should be offered co-amoxiclav, cefuroxime, clindamycin, or ceftriaxone. Understanding the symptoms, diagnosis, and treatment of cellulitis is crucial for effective management and prevention of complications.
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This question is part of the following fields:
- General Principles
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Question 17
Incorrect
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Which muscles are responsible for flexing the hip joint?
Your Answer:
Correct Answer: Psoas
Explanation:Muscles and their Functions in Joint Movement
The hip joint has three main flexors, namely the iliacus, psoas, and rectus femoris muscles. These muscles are responsible for flexing the hip joint, which is the movement of bringing the thigh towards the abdomen. On the other hand, the gluteus maximus and medius muscles are involved in hip extension, which is the movement of bringing the thigh backward.
Moving on to the elbow joint, the bicep femoris muscle is one of the primary flexors. This muscle is responsible for bending the elbow, which is the movement of bringing the forearm towards the upper arm. Lastly, the adductor brevis muscle is responsible for adducting the leg at the hip joint, which is the movement of bringing the leg towards the midline of the body.
In summary, muscles play a crucial role in joint movement. the functions of these muscles can help in identifying and addressing issues related to joint movement and mobility.
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This question is part of the following fields:
- Clinical Sciences
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Question 18
Incorrect
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A young farmer suffers an accident with crop-spraying equipment and is drenched with insecticide. Upon arrival at the emergency department, he presents with severe bradycardia, shortness of breath, and excessive salivation. What are the possible mechanisms of poisoning in this case?
Your Answer:
Correct Answer: Acetylcholinesterase inhibition
Explanation:Excessive salivation, dyspnea, and bradycardia are some of the symptoms that may result from anticholinesterase poisoning.
Organophosphorus insecticides are potent and long-acting anticholinesterases that cause overactivity at parasympathetic receptors, leading to clinical features. Bronchospasm may cause breathlessness. Respiratory muscle paralysis and coma are the main acute effects of massive exposure.
To counteract excessive acetylcholinergic activity in the autonomic nervous system, atropine is used. Pralidoxime is used to regenerate acetylcholinesterase.
Salicylate poisoning occurs due to an overdose of aspirin. Symptoms after drug ingestion include abdominal pain, nausea, tinnitus, deafness, vertigo, and hyperpnea. Rehydration is crucial for general care. In severe cases, drug elimination can be enhanced by hemodialysis.
Lithium is a mood stabilizing drug commonly used in bipolar depression. Acute lithium toxicity results in various neurological effects, progressing from confusion and motor impairment to coma, convulsions, and death. As lithium is excreted renally, fluid therapy is the mainstay of treatment.
Paracetamol poisoning results in glutathione depletion. N-acetylcysteine, a glutathione precursor, is used as an antidote.
Cholinergic receptors are proteins found in the body that are activated by the neurotransmitter acetylcholine. They are present in both the central and peripheral nervous systems and can be divided into two groups: nicotinic and muscarinic receptors. Nicotinic receptors are ligand-gated ion channels that allow the movement of sodium into the cell and potassium out, resulting in an inward flow of positive ions. Muscarinic receptors, on the other hand, are G-protein coupled receptors that exert their downstream effect by linking with different G-proteins.
Nicotinic receptors are named after their binding capacity for nicotine, but they respond to acetylcholine. They are found in preganglionic neurons of the autonomic nervous system and at neuromuscular junctions. At preganglionic neurons, they create a local membrane depolarization through the movement of sodium into the cell, while at neuromuscular junctions, they initiate a wave of depolarization across the muscle cell. Muscarinic receptors are found in effector organs of the parasympathetic autonomic nervous system and are divided into five classes. They mediate various effects through different G-protein systems.
Cholinergic receptors can be targeted pharmacologically using agonists and antagonists. For example, muscarinic antagonist ipratropium can be used to induce bronchodilation in asthma or chronic obstructive pulmonary disease. In myasthenia gravis, an autoimmune disease, antibodies are directed against the nicotinic receptor on the neuromuscular junction, resulting in skeletal muscle weakness. Understanding the effects associated with each type of cholinergic receptor is important in understanding physiological responses to drugs and disease.
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This question is part of the following fields:
- General Principles
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Question 19
Incorrect
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A 47-year-old man has a nasogastric tube inserted. The nurse takes a small aspirate of the fluid from the stomach and tests the pH of the aspirate. What is the typical intragastric pH?
Your Answer:
Correct Answer: 2
Explanation:Typically, the pH level in the stomach is 2, but the use of proton pump inhibitors can effectively eliminate acidity.
Understanding Gastric Secretions for Surgical Procedures
A basic understanding of gastric secretions is crucial for surgeons, especially when dealing with patients who have undergone acid-lowering procedures or are prescribed anti-secretory drugs. Gastric acid, produced by the parietal cells in the stomach, has a pH of around 2 and is maintained by the H+/K+ ATPase pump. Sodium and chloride ions are actively secreted from the parietal cell into the canaliculus, creating a negative potential across the membrane. Carbonic anhydrase forms carbonic acid, which dissociates, and the hydrogen ions formed by dissociation leave the cell via the H+/K+ antiporter pump. This leaves hydrogen and chloride ions in the canaliculus, which mix and are secreted into the lumen of the oxyntic gland.
There are three phases of gastric secretion: the cephalic phase, gastric phase, and intestinal phase. The cephalic phase is stimulated by the smell or taste of food and causes 30% of acid production. The gastric phase, which is caused by stomach distension, low H+, or peptides, causes 60% of acid production. The intestinal phase, which is caused by high acidity, distension, or hypertonic solutions in the duodenum, inhibits gastric acid secretion via enterogastrones and neural reflexes.
The regulation of gastric acid production involves various factors that increase or decrease production. Factors that increase production include vagal nerve stimulation, gastrin release, and histamine release. Factors that decrease production include somatostatin, cholecystokinin, and secretin. Understanding these factors and their associated pharmacology is essential for surgeons.
In summary, a working knowledge of gastric secretions is crucial for surgical procedures, especially when dealing with patients who have undergone acid-lowering procedures or are prescribed anti-secretory drugs. Understanding the phases of gastric secretion and the regulation of gastric acid production is essential for successful surgical outcomes.
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This question is part of the following fields:
- Gastrointestinal System
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Question 20
Incorrect
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A young surgical trainee is preparing for her first hemi arthroplasty for a fractured neck of femur. During the pre-operative assessment, the patient reports a possible history of penicillin allergy, but due to the patient's confusion, the history is not confirmed. In the anaesthetic room, the patient is given 1.2g intravenous co-amoxiclav. Suddenly, the patient experiences severe respiratory distress and haemodynamic collapse. What pathological process could be responsible for this event?
Your Answer:
Correct Answer: Recognition of the drug by IgE receptors on mast cells
Explanation:Anaphylactic shock occurs when an antigen is recognized by IgE molecules on mast cells, leading to their rapid degranulation and the release of histamine and other inflammatory cytokines.
Anaphylaxis is a severe and potentially life-threatening allergic reaction that affects the entire body. It can be caused by various triggers, including food, drugs, and insect venom. The symptoms of anaphylaxis typically develop suddenly and progress rapidly, affecting the airway, breathing, and circulation. Swelling of the throat and tongue, hoarse voice, and stridor are common airway problems, while respiratory wheeze and dyspnea are common breathing problems. Hypotension and tachycardia are common circulation problems. Skin and mucosal changes, such as generalized pruritus and widespread erythematous or urticarial rash, are also present in around 80-90% of patients.
The most important drug in the management of anaphylaxis is intramuscular adrenaline, which should be administered as soon as possible. The recommended doses of adrenaline vary depending on the patient’s age, with the highest dose being 500 micrograms for adults and children over 12 years old. Adrenaline can be repeated every 5 minutes if necessary. If the patient’s respiratory and/or cardiovascular problems persist despite two doses of IM adrenaline, IV fluids should be given for shock, and expert help should be sought for consideration of an IV adrenaline infusion.
Following stabilisation, non-sedating oral antihistamines may be given to patients with persisting skin symptoms. Patients with a new diagnosis of anaphylaxis should be referred to a specialist allergy clinic, and an adrenaline injector should be given as an interim measure before the specialist allergy assessment. Patients should be prescribed two adrenaline auto-injectors, and training should be provided on how to use them. A risk-stratified approach to discharge should be taken, as biphasic reactions can occur in up to 20% of patients. The Resus Council UK recommends a fast-track discharge for patients who have had a good response to a single dose of adrenaline and have been given an adrenaline auto-injector and trained how to use it. Patients who require two doses of IM adrenaline or have had a previous biphasic reaction should be observed for a minimum of 6 hours after symptom resolution, while those who have had a severe reaction requiring more than two doses of IM adrenaline or have severe asthma should be observed for a minimum of 12 hours after symptom resolution. Patients who present late at night or in areas where access to emergency care may be difficult should also be observed for a minimum of 12
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This question is part of the following fields:
- General Principles
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Question 21
Incorrect
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What are the two essential components found in all viruses?
Your Answer:
Correct Answer: Genomic material and capsid
Explanation:The Structure of Viruses
Viral structure can differ greatly, but all viruses contain some form of genetic material (either DNA or RNA, single or double-stranded) enclosed in a protein coat called the capsid. The capsid is responsible for packaging the replicated genome inside and can theoretically transcribe only two or three proteins to make it.
Some viruses have a lipid coating, known as an envelope, which aids in evading the immune system and entering cells. The envelope can also have surface glycoproteins that are involved in attachment, but these glycoproteins are different from and external to the capsid.
Certain RNA viruses have reverse transcriptase, which allows for the formation of DNA from RNA, such as HIV. However, not all viruses have RNA or reverse transcriptase.
Overall, the structure of viruses can vary, but they all contain genetic material enclosed in a protein coat, with some having an additional lipid coating and surface glycoproteins.
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This question is part of the following fields:
- Microbiology
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Question 22
Incorrect
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Sarah, a 23-year-old female, visits the clinic to have her 8-week plaster cast removed from her lower limb. During the examination, it is observed that her right foot is in a plantar flexed position, indicating foot drop.
The physician proceeds to assess the sensation in Sarah's lower limb and feet and discovers a reduction in the area innervated by the deep fibular nerve.
What specific region of Sarah's lower limb or foot is likely to be impacted by this condition?Your Answer:
Correct Answer: Webspace between the first and second toes
Explanation:The webbing between the first and second toes is innervated by the deep fibular nerve. The saphenous nerve, which arises from the femoral nerve, provides cutaneous innervation to the medial aspect of the leg. The sural nerve, which arises from the common fibular and tibial nerves, innervates the lateral foot. The majority of innervation to the dorsum of the foot comes from the superficial fibular nerve.
The common peroneal nerve originates from the dorsal divisions of the sacral plexus, specifically from L4, L5, S1, and S2. This nerve provides sensation to the skin and fascia of the anterolateral surface of the leg and dorsum of the foot, as well as innervating the muscles of the anterior and peroneal compartments of the leg, extensor digitorum brevis, and the knee, ankle, and foot joints. It is located laterally within the sciatic nerve and passes through the lateral and proximal part of the popliteal fossa, under the cover of biceps femoris and its tendon, to reach the posterior aspect of the fibular head. The common peroneal nerve divides into the deep and superficial peroneal nerves at the point where it winds around the lateral surface of the neck of the fibula in the body of peroneus longus, approximately 2 cm distal to the apex of the head of the fibula. It is palpable posterior to the head of the fibula. The nerve has several branches, including the nerve to the short head of biceps, articular branch (knee), lateral cutaneous nerve of the calf, and superficial and deep peroneal nerves at the neck of the fibula.
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This question is part of the following fields:
- Neurological System
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Question 23
Incorrect
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A 14-year-old boy comes to the clinic complaining of ear pain. He mentions having some crusty discharge at the entrance of his ear canal when he woke up this morning. He denies any hearing loss, dizziness, or other symptoms. He swims twice a week. Upon examination, he has no fever. The auricle of his ear appears red, and pressing on the tragus causes discomfort. Otoscopy reveals an erythematous canal with a small amount of yellow discharge. The superior edge of the tympanic membrane is also red, but there is no bulging or fluid in the middle ear. Which bone articulates with the bone that is typically seen pressing against the tympanic membrane?
Your Answer:
Correct Answer: Incus
Explanation:The middle bone of the 3 ossicles is known as the incus. During otoscopy, the malleus can be observed in contact with the tympanic membrane and it connects with the incus medially.
The ossicles, which are the 3 bones in the middle ear, are arranged from lateral to medial as follows:
Malleus: This is the most lateral of the ossicles. The handle and lateral process of the malleus attach to the tympanic membrane, making it visible during otoscopy. The head of the malleus connects with the incus. The term ‘malleus’ is derived from the Latin word for ‘hammer’.
Incus: The incus is positioned between and connects with the other two ossicles. The body of the incus connects with the malleus, while the long limb of the bone connects with the stapes. The term ‘incus’ is derived from the Latin word for ‘anvil’.Anatomy of the Ear
The ear is divided into three distinct regions: the external ear, middle ear, and internal ear. The external ear consists of the auricle and external auditory meatus, which are innervated by the greater auricular nerve and auriculotemporal branch of the trigeminal nerve. The middle ear is the space between the tympanic membrane and cochlea, and is connected to the nasopharynx by the eustachian tube. The tympanic membrane is composed of three layers and is approximately 1 cm in diameter. The middle ear is innervated by the glossopharyngeal nerve. The ossicles, consisting of the malleus, incus, and stapes, transmit sound vibrations from the tympanic membrane to the inner ear. The internal ear contains the cochlea, which houses the organ of corti, the sense organ of hearing. The vestibule accommodates the utricule and saccule, which contain endolymph and are surrounded by perilymph. The semicircular canals, which share a common opening into the vestibule, lie at various angles to the petrous temporal bone.
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This question is part of the following fields:
- Respiratory System
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Question 24
Incorrect
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A 70-year-old female is brought to the Emergency department with a severe crushing chest pain that was alleviated by sublingual GTN. The medical team diagnoses her with acute coronary syndrome (ACS). What test can distinguish between unstable angina and non-ST elevation MI (NSTEMI), both of which are types of ACS?
Your Answer:
Correct Answer: Troponin level
Explanation:Acute Coronary Syndrome
Acute coronary syndrome is a term used to describe a range of conditions that affect the heart, including unstable angina, non-ST elevation MI (NSTEMI), and ST elevation MI (STEMI). The detection of raised cardiac enzymes is the definitive test in distinguishing between NSTEMI and unstable angina. If the enzymes are raised, it indicates myocardial tissue infarction, which is present in NSTEMI but not in unstable angina. Clinical history and exercise ECG testing are also important in distinguishing between these conditions. It is important to understand the differences between these conditions in order to provide appropriate treatment and management.
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This question is part of the following fields:
- Cardiovascular System
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Question 25
Incorrect
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A 14-year-old girl presents to the general practitioner with fever, malaise, involuntary movements of the neck and arms and erythema marginatum. She was previously unwell with tonsillitis six weeks ago. She is taken to the hospital and after a series of investigations is diagnosed with rheumatic fever.
What is the underlying pathology of this condition?Your Answer:
Correct Answer: Molecular mimicry of the bacterial M protein
Explanation:The development of rheumatic fever is caused by molecular mimicry of the bacterial M protein. This results in the patient experiencing constitutional symptoms such as fever and malaise, involuntary movements of the neck and arms known as Sydenham chorea, and a distinctive rash called erythema marginatum. The antibodies produced against the M protein cross-react with myosin and smooth muscle in arteries, leading to the characteristic features of rheumatic fever. Autoimmune demyelination of peripheral nerves, autoimmune demyelination of the central nervous system, and autoimmune destruction of postsynaptic acetylcholine receptors are all incorrect as they are the pathophysiology of other conditions such as Guillain Barre syndrome, multiple sclerosis, and myasthenia gravis, respectively.
Rheumatic fever is a condition that occurs as a result of an immune response to a recent Streptococcus pyogenes infection, typically occurring 2-4 weeks after the initial infection. The pathogenesis of rheumatic fever involves the activation of the innate immune system, leading to antigen presentation to T cells. B and T cells then produce IgG and IgM antibodies, and CD4+ T cells are activated. This immune response is thought to be cross-reactive, mediated by molecular mimicry, where antibodies against M protein cross-react with myosin and the smooth muscle of arteries. This response leads to the clinical features of rheumatic fever, including Aschoff bodies, which are granulomatous nodules found in rheumatic heart fever.
To diagnose rheumatic fever, evidence of recent streptococcal infection must be present, along with 2 major criteria or 1 major criterion and 2 minor criteria. Major criteria include erythema marginatum, Sydenham’s chorea, polyarthritis, carditis and valvulitis, and subcutaneous nodules. Minor criteria include raised ESR or CRP, pyrexia, arthralgia, and prolonged PR interval.
Management of rheumatic fever involves antibiotics, typically oral penicillin V, as well as anti-inflammatories such as NSAIDs as first-line treatment. Any complications that develop, such as heart failure, should also be treated. It is important to diagnose and treat rheumatic fever promptly to prevent long-term complications such as rheumatic heart disease.
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This question is part of the following fields:
- Cardiovascular System
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Question 26
Incorrect
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Which one of the following would cause a rise in the carbon monoxide transfer factor (TLCO)?
Your Answer:
Correct Answer: Pulmonary haemorrhage
Explanation:When alveolar haemorrhage takes place, the TLCO typically rises as a result of the increased absorption of carbon monoxide by haemoglobin within the alveoli.
Understanding Transfer Factor in Lung Function Testing
The transfer factor is a measure of how quickly a gas diffuses from the alveoli into the bloodstream. This is typically tested using carbon monoxide, and the results can be given as either the total gas transfer (TLCO) or the transfer coefficient corrected for lung volume (KCO). A raised TLCO may be caused by conditions such as asthma, pulmonary haemorrhage, left-to-right cardiac shunts, polycythaemia, hyperkinetic states, male gender, or exercise. On the other hand, a lower TLCO may be indicative of pulmonary fibrosis, pneumonia, pulmonary emboli, pulmonary oedema, emphysema, anaemia, or low cardiac output.
KCO tends to increase with age, and certain conditions may cause an increased KCO with a normal or reduced TLCO. These conditions include pneumonectomy/lobectomy, scoliosis/kyphosis, neuromuscular weakness, and ankylosis of costovertebral joints (such as in ankylosing spondylitis). Understanding transfer factor is important in lung function testing, as it can provide valuable information about a patient’s respiratory health and help guide treatment decisions.
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This question is part of the following fields:
- Respiratory System
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Question 27
Incorrect
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A 35-year-old female who has previously had a colectomy for familial adenomatous polyposis coli complains of a solid mass located at the lower part of her rectus abdominis muscle. What type of cell is commonly linked with these types of tumors?
Your Answer:
Correct Answer: Myofibroblasts
Explanation:The most probable differential diagnosis in this case would be desmoid tumors, which involve the abnormal growth of myofibroblast cells.
Desmoid tumours are growths that arise from musculoaponeurotic structures and are made up of clonal proliferations of myofibroblasts. They are typically firm and have a tendency to infiltrate surrounding tissue. These tumours are often seen in patients with familial adenomatous polyposis coli, and are most commonly found in women after childbirth in the rectus abdominis muscle. Bi allelic APC mutations are usually present in desmoid tumours.
The preferred treatment for desmoid tumours is radical surgical resection, although radiotherapy and chemotherapy may be considered in some cases. Non-surgical therapy is generally less effective than surgical resection. In certain cases of abdominal desmoids, observation may be preferred as some tumours may spontaneously regress. However, desmoids have a high likelihood of local recurrence. These tumours consist of sheets of differentiated fibroblasts.
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This question is part of the following fields:
- Gastrointestinal System
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Question 28
Incorrect
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A 58-year-old woman is admitted under the gynaecology team with vaginal bleeding. She has a history of breast cancer and is taking letrozole 2.5 mg.
What is the mechanism of action of letrozole?Your Answer:
Correct Answer: Reduces peripheral oestrogen synthesis
Explanation:Anti-oestrogen drugs are used in the management of oestrogen receptor-positive breast cancer. Selective oEstrogen Receptor Modulators (SERM) such as Tamoxifen act as an oestrogen receptor antagonist and partial agonist. However, Tamoxifen may cause adverse effects such as menstrual disturbance, hot flushes, venous thromboembolism, and endometrial cancer. On the other hand, aromatase inhibitors like Anastrozole and Letrozole reduce peripheral oestrogen synthesis, which is important in postmenopausal women. Anastrozole is used for ER +ve breast cancer in this group. However, aromatase inhibitors may cause adverse effects such as osteoporosis, hot flushes, arthralgia, myalgia, and insomnia. NICE recommends a DEXA scan when initiating a patient on aromatase inhibitors for breast cancer.
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This question is part of the following fields:
- Reproductive System
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Question 29
Incorrect
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A 65-year-old man, who has a history of non-Hodgkin's lymphoma, is scheduled to start chemotherapy treatment. During his consultation with the oncologist, he expressed concern about the potential side effects of his chemotherapy drugs. Specifically, he is worried about the side effects associated with vincristine.
What side effect is commonly linked to the use of vincristine in chemotherapy treatment?Your Answer:
Correct Answer: Peripheral neuropathy
Explanation:Vincristine is a medication that belongs to the vinca alkaloid class and works by inhibiting microtubule formation, which prevents the cell cycle from progressing beyond the metaphase stage. However, it is commonly associated with peripheral neuropathy as a side effect.
Anthracyclines, such as doxorubicin, are known to cause cardiomyopathy. These medications stabilize topoisomerase II, which prevents DNA replication by inhibiting the coiling of DNA.
5-fluorouracil is a thymidylate synthase inhibitor that is associated with dermatitis. It works by preventing the formation of the thymidine nucleotide, which is essential for DNA replication. Palmar-plantar erythrodysesthesia is a severe form of dermatitis that can occur as a blistering rash on the hands and feet of patients taking this medication.
Cytotoxic agents are drugs that are used to kill cancer cells. There are several types of cytotoxic agents, each with their own mechanism of action and potential adverse effects. Alkylating agents, such as cyclophosphamide, work by causing cross-linking in DNA. However, they can also cause haemorrhagic cystitis, myelosuppression, and transitional cell carcinoma. Cytotoxic antibiotics, like bleomycin and anthracyclines, degrade preformed DNA and stabilize DNA-topoisomerase II complex, respectively. However, they can also cause lung fibrosis and cardiomyopathy. Antimetabolites, such as methotrexate and fluorouracil, inhibit dihydrofolate reductase and thymidylate synthesis, respectively. However, they can also cause myelosuppression, mucositis, and liver or lung fibrosis. Drugs that act on microtubules, like vincristine and docetaxel, inhibit the formation of microtubules and prevent microtubule depolymerisation & disassembly, respectively. However, they can also cause peripheral neuropathy, myelosuppression, and paralytic ileus. Topoisomerase inhibitors, like irinotecan, inhibit topoisomerase I, which prevents relaxation of supercoiled DNA. However, they can also cause myelosuppression. Other cytotoxic drugs, such as cisplatin and hydroxyurea, cause cross-linking in DNA and inhibit ribonucleotide reductase, respectively. However, they can also cause ototoxicity, peripheral neuropathy, hypomagnesaemia, and myelosuppression.
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This question is part of the following fields:
- Haematology And Oncology
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Question 30
Incorrect
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A 41-year-old male presents to the general practitioner with a 4-month history of a lump in his right testicle. On examination, there is a discrete nodule located near the superior pole of the right testicle and the left testicle is unremarkable. The patient is referred for further investigations and is ultimately diagnosed with a testicular seminoma.
In this patient, what is the most likely lymph node region for initial metastatic spread?Your Answer:
Correct Answer: Para-aortic nodes
Explanation:The para-aortic nodes are responsible for receiving lymph drainage from the testes. This is because the testes develop in the abdomen and move down the posterior abdominal wall during fetal development, leading to their lymphatic drainage coming from the para-aortic lymph nodes. Therefore, the para-aortic nodes are the most likely location for lymphatic spread from the testes.
The inferior mesenteric nodes are not responsible for lymph drainage from the testes as they primarily drain hindgut structures such as the transverse colon down to the rectum. Similarly, the internal iliac nodes drain the inferior portion of the rectum, the anal canal superior to the pectinate line, and the pelvic viscera, but not the testes. The posterior mediastinal chain is also not responsible for lymph drainage from the testes as it drains the oesophagus, mediastinum, and posterior surface of the diaphragm.
Lymphatic drainage is the process by which lymphatic vessels carry lymph, a clear fluid containing white blood cells, away from tissues and organs and towards lymph nodes. The lymphatic vessels that drain the skin and follow venous drainage are called superficial lymphatic vessels, while those that drain internal organs and structures follow the arteries and are called deep lymphatic vessels. These vessels eventually lead to lymph nodes, which filter and remove harmful substances from the lymph before it is returned to the bloodstream.
The lymphatic system is divided into two main ducts: the right lymphatic duct and the thoracic duct. The right lymphatic duct drains the right side of the head and right arm, while the thoracic duct drains everything else. Both ducts eventually drain into the venous system.
Different areas of the body have specific primary lymph node drainage sites. For example, the superficial inguinal lymph nodes drain the anal canal below the pectinate line, perineum, skin of the thigh, penis, scrotum, and vagina. The deep inguinal lymph nodes drain the glans penis, while the para-aortic lymph nodes drain the testes, ovaries, kidney, and adrenal gland. The axillary lymph nodes drain the lateral breast and upper limb, while the internal iliac lymph nodes drain the anal canal above the pectinate line, lower part of the rectum, and pelvic structures including the cervix and inferior part of the uterus. The superior mesenteric lymph nodes drain the duodenum and jejunum, while the inferior mesenteric lymph nodes drain the descending colon, sigmoid colon, and upper part of the rectum. Finally, the coeliac lymph nodes drain the stomach.
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This question is part of the following fields:
- Haematology And Oncology
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