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Question 1
Incorrect
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A 28-year-old woman presents with recurrent slurring of speech that worsens when she continues to talk. She also reports feeling tired constantly, is occasionally short of breath and has experienced some double vision that gets worse when reading or watching TV. Her symptoms have progressively deteriorated over the past 4 months and she has intermittent weakness in her legs and arms, she feels as though her legs will give way when she gets up from her chair and has difficulty combing her hair.
On examination the patient appears well, there appears to be mild ptosis bilaterally and also a midline neck lump. The patient was referred to the neurology team and is due for further investigation.
What is the initial test that should be done?Your Answer: Pulmonary function tests
Correct Answer: Serum acetylcholine receptor (AChR) antibody analysis
Explanation:Myasthenia gravis is an autoimmune disorder that results in muscle weakness and fatigue, particularly in the eyes, face, neck, and limbs. It is more common in women and is associated with thymomas and other autoimmune disorders. Diagnosis is made through electromyography and testing for antibodies to acetylcholine receptors. Treatment includes acetylcholinesterase inhibitors and immunosuppression, and in severe cases, plasmapheresis or intravenous immunoglobulins may be necessary.
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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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A familiar alcohol dependent woman arrives at the emergency department with ophthalmoplegia, ataxia and confusion. She is administered IV pabrinex to rectify the probable vitamin deficiency causing her symptoms.
What is the function of this vitamin within the body?Your Answer: Catabolism of fats
Correct Answer: Catabolism of sugars and amino acids
Explanation:Thiamine plays a crucial role in breaking down sugars and amino acids. When there is a deficiency of thiamine, it can lead to Wernicke’s encephalopathy, which is commonly seen in individuals with alcohol dependence or malnutrition.
The deficiency of thiamine affects the highly aerobic tissues of the brain and heart, resulting in conditions like Wernicke-Korsakoff syndrome or beriberi.
Retinal production requires Vitamin A, while collagen synthesis needs Vitamin C. Vitamin D helps in increasing plasma calcium and phosphate levels.
The Importance of Vitamin B1 (Thiamine) in the Body
Vitamin B1, also known as thiamine, is a water-soluble vitamin that belongs to the B complex group. It plays a crucial role in the body as one of its phosphate derivatives, thiamine pyrophosphate (TPP), acts as a coenzyme in various enzymatic reactions. These reactions include the catabolism of sugars and amino acids, such as pyruvate dehydrogenase complex, alpha-ketoglutarate dehydrogenase complex, and branched-chain amino acid dehydrogenase complex.
Thiamine deficiency can lead to clinical consequences, particularly in highly aerobic tissues like the brain and heart. The brain can develop Wernicke-Korsakoff syndrome, which presents symptoms such as nystagmus, ophthalmoplegia, and ataxia. Meanwhile, the heart can develop wet beriberi, which causes dilated cardiomyopathy. Other conditions associated with thiamine deficiency include dry beriberi, which leads to peripheral neuropathy, and Korsakoff’s syndrome, which causes amnesia and confabulation.
The primary causes of thiamine deficiency are alcohol excess and malnutrition. Alcoholics are routinely recommended to take thiamine supplements to prevent deficiency. Overall, thiamine is an essential vitamin that plays a vital role in the body’s metabolic processes.
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This question is part of the following fields:
- General Principles
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Question 3
Correct
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A 39-year-old woman presents to the endocrine clinic after being referred by her GP due to a blood pressure reading of 178/101 mm Hg. Upon blood tests, it is discovered that she has hypernatremia and hypokalaemia, along with an elevated aldosterone level. An inconclusive CT scan of the abdomen has been performed to determine if there is an adenoma present.
What is the most suitable investigation to identify if one of the adrenal glands is producing an excess of hormones?Your Answer: Adrenal venous sampling (AVS)
Explanation:Adrenal venous sampling (AVS) is the most appropriate investigation to differentiate between unilateral adenoma and bilateral hyperplasia in primary hyperaldosteronism. This method involves catheterizing the adrenal veins and collecting blood samples from each, which can be tested for hormone levels. The affected side can then be surgically removed if necessary. Other options such as surgical removal of adrenals and immunohistochemistry, adrenal biopsy, or repeat CT scan are not as suitable or effective in this scenario.
Primary hyperaldosteronism is a condition characterized by hypertension, hypokalaemia, and alkalosis. It was previously believed that adrenal adenoma, also known as Conn’s syndrome, was the most common cause of this condition. However, recent studies have shown that bilateral idiopathic adrenal hyperplasia is responsible for up to 70% of cases. It is important to differentiate between the two causes as it determines the appropriate treatment. Adrenal carcinoma is an extremely rare cause of primary hyperaldosteronism.
To diagnose primary hyperaldosteronism, the 2016 Endocrine Society recommends a plasma aldosterone/renin ratio as the first-line investigation. This test should show high aldosterone levels alongside low renin levels due to negative feedback from sodium retention caused by aldosterone. If the results are positive, a high-resolution CT abdomen and adrenal vein sampling are used to differentiate between unilateral and bilateral sources of aldosterone excess. If the CT is normal, adrenal venous sampling (AVS) can be used to distinguish between unilateral adenoma and bilateral hyperplasia.
The management of primary hyperaldosteronism depends on the underlying cause. Adrenal adenoma is treated with surgery, while bilateral adrenocortical hyperplasia is managed with an aldosterone antagonist such as spironolactone. It is important to accurately diagnose and manage primary hyperaldosteronism to prevent complications such as cardiovascular disease and stroke.
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This question is part of the following fields:
- Endocrine System
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Question 4
Incorrect
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A 72-year-old male presents to the emergency department with severe, central abdominal pain that is radiating to his back. He has vomited twice and on examination you find he has hypotension and tachycardia. He is a current smoker with a past medical history of hypertension and hypercholesterolaemia. You suspect a visceral artery aneurysm and urgently request a CT scan to confirm. The CT scan reveals an aneurysm in the superior mesenteric artery.
From which level of the vertebrae does this artery originate from the aorta?Your Answer: T10
Correct Answer: L1
Explanation:The common iliac veins come together at
Anatomical Planes and Levels in the Human Body
The human body can be divided into different planes and levels to aid in anatomical study and medical procedures. One such plane is the transpyloric plane, which runs horizontally through the body of L1 and intersects with various organs such as the pylorus of the stomach, left kidney hilum, and duodenojejunal flexure. Another way to identify planes is by using common level landmarks, such as the inferior mesenteric artery at L3 or the formation of the IVC at L5.
In addition to planes and levels, there are also diaphragm apertures located at specific levels in the body. These include the vena cava at T8, the esophagus at T10, and the aortic hiatus at T12. By understanding these planes, levels, and apertures, medical professionals can better navigate the human body during procedures and accurately diagnose and treat various conditions.
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This question is part of the following fields:
- Neurological System
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Question 5
Incorrect
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The following blood gas results are obtained from a young adult patient with diabetes.
pH 7.32 (7.36-7.44)
PaO2 14.5 kPa (11.3-12.6)
PaCO2 2.7 kPa (4.7-6.0)
HCO3- 14 mmol/L (20-28)
Base excess â10 mmol/L (+/-2)
How should this data be interpreted accurately?Your Answer: Diabetic ketoacidosis (DKA)
Correct Answer: Metabolic acidosis with partial respiratory compensation
Explanation:Acidosis and its Causes
Acidosis is a condition characterized by a low pH level, which can be caused by various factors. In this particular case, the patient’s pH level is 7.32, indicating acidosis. The low bicarbonate level suggests that the origin of the acidosis is metabolic, and the low base excess supports this. The lungs are compensating for the acidosis by increasing the clearance of carbon dioxide, resulting in a low PaCO2 level. However, it is important to note that compensation rarely reverses the pH change completely, and the patient is still considered to have metabolic acidosis.
It is crucial not to jump to conclusions about the cause of acidosis without appropriate information. While diabetic ketoacidosis (DKA) is a common cause, other factors such as lactic acidosis (type A or B) or poisoning can also lead to acidosis. Therefore, a thorough evaluation is necessary to determine the underlying cause and provide appropriate treatment. the different types and causes of acidosis is essential for healthcare professionals to provide effective care for their patients.
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This question is part of the following fields:
- Clinical Sciences
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Question 6
Incorrect
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A woman in her early pregnancy has her kidney function assessed during a regular check-up. It is observed that her plasma urea and creatinine levels have decreased compared to her pre-pregnancy levels. What is the reason for this change?
Your Answer: Increased frequency of micturition
Correct Answer: Increased renal perfusion
Explanation:During pregnancy, plasma urea and creatinine levels decrease due to increased renal perfusion, which allows for more efficient clearing of these substances from the circulation. Additionally, the increased plasma volume dilutes these substances. This is a result of physiological changes in pregnancy, such as increased uterine size, cervical ectropion, and increased vaginal discharge. Cardiovascular and haemodynamic changes also occur, including increased plasma volume and decreased levels of albumin, urea, and creatinine. Progesterone-related effects, such as muscle relaxation, can lead to decreased blood pressure, constipation, and bladder relaxation. It is important to note that the foetus does not have functioning kidneys, and the mother filters the blood for it.
During pregnancy, a woman’s body undergoes various physiological changes. The cardiovascular system experiences an increase in stroke volume, heart rate, and cardiac output, while systolic blood pressure remains unchanged and diastolic blood pressure decreases in the first and second trimesters before returning to normal levels by term. The enlarged uterus may cause issues with venous return, leading to ankle swelling, supine hypotension, and varicose veins.
The respiratory system sees an increase in pulmonary ventilation and tidal volume, with oxygen requirements only increasing by 20%. This can lead to a sense of dyspnea due to over-breathing and a fall in pCO2. The basal metabolic rate also increases, potentially due to increased thyroxine and adrenocortical hormones.
Maternal blood volume increases by 30%, with red blood cells increasing by 20% and plasma increasing by 50%, leading to a decrease in hemoglobin levels. Coagulant activity increases slightly, while fibrinolytic activity decreases. Platelet count falls, and white blood cell count and erythrocyte sedimentation rate rise.
The urinary system experiences an increase in blood flow and glomerular filtration rate, with elevated sex steroid levels leading to increased salt and water reabsorption and urinary protein losses. Trace glycosuria may also occur.
Calcium requirements increase during pregnancy, with gut absorption increasing substantially due to increased 1,25 dihydroxy vitamin D. Serum levels of calcium and phosphate may fall, but ionized calcium levels remain stable. The liver experiences an increase in alkaline phosphatase and a decrease in albumin levels.
The uterus undergoes significant changes, increasing in weight from 100g to 1100g and transitioning from hyperplasia to hypertrophy. Cervical ectropion and discharge may increase, and Braxton-Hicks contractions may occur in late pregnancy. Retroversion may lead to retention in the first trimester but usually self-corrects.
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This question is part of the following fields:
- Reproductive System
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Question 7
Incorrect
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An 8-year-old boy is brought to the general practice by his father. The father has observed several peculiar episodes where his son would stop what he was doing and become unresponsive to sounds and touch for 5-10 seconds. The doctor suspects epilepsy as the cause.
What EEG pattern is typical of the underlying condition?Your Answer: Normal EEG pattern
Correct Answer: 3Hz spike-and-wave
Explanation:An absence seizure is characterized by 3Hz oscillations on EEG, making it a defining feature. Therefore, EEG is the primary diagnostic tool used to detect absence seizures.
Absence seizures, also known as petit mal, are a type of epilepsy that is commonly observed in children. This form of generalised epilepsy typically affects children between the ages of 3-10 years old, with girls being twice as likely to be affected as boys. Absence seizures are characterised by brief episodes that last only a few seconds and are followed by a quick recovery. These seizures may be triggered by hyperventilation or stress, and the child is usually unaware of the seizure. They may occur multiple times a day and are identified by a bilateral, symmetrical 3Hz spike and wave pattern on an EEG.
The first-line treatment for absence seizures includes sodium valproate and ethosuximide. The prognosis for this condition is generally good, with 90-95% of affected individuals becoming seizure-free during adolescence.
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This question is part of the following fields:
- Neurological System
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Question 8
Correct
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A 13-year-old boy presents to his pediatrician with complaints of red-colored urine and foamy urine for a while. His parents also noticed puffiness in his face and high blood pressure for his age and sex. The boy has been complaining of hearing difficulties in class and requested to be seated in front. The doctor suspects a genetically inherited disease that is passed down from affected mothers to fifty percent of their daughters and from fathers to all their sons. What is the underlying pathology of this patient's condition?
Your Answer: Abnormal type IV collagen causing glomerular basement membrane splitting
Explanation:The patient’s symptoms suggest a combination of nephritic and nephrotic syndrome, along with hearing problems, indicating a likely diagnosis of Alport syndrome. This X-linked dominant condition is caused by a defect in type IV collagen, which forms the basement membrane. The glomerular basement membrane in Alport syndrome is characterized by thinning and thickening with areas of splitting, resulting in a basketweave appearance on electron microscopy. The condition is inherited from affected mothers to 50% of their daughters and from fathers to all their sons.
IgA nephropathy, also known as Berger disease, is characterized by IgA-based mesangial deposits on immunofluorescence and mesangial proliferation on light microscopy. Type 1 membranoproliferative glomerulonephritis presents with symptoms of both nephritic and nephrotic syndrome and is characterized by a tram-track appearance on periodic acid-Schiff stain due to mesangium proliferating into the glomerular basement membrane. Subendothelial immunocomplex deposits are seen on immunofluorescence. Poststreptococcal glomerulonephritis is a type of nephritic syndrome that occurs after a group A streptococcal infection and is characterized by enlarged and hypercellular glomeruli on light microscopy and subepithelial immunocomplexes on electron microscopy. Diffuse proliferative glomerulonephritis, often seen in SLE patients, presents with symptoms of both nephritic and nephrotic syndrome and is characterized by wire looping of capillaries on light microscopy and subendothelial immunocomplex deposits on electron microscopy. A granular appearance is found on immunofluorescence.
Alport’s syndrome is a genetic disorder that is typically inherited in an X-linked dominant pattern. It is caused by a defect in the gene responsible for producing type IV collagen, which leads to an abnormal glomerular-basement membrane (GBM). The disease is more severe in males, with females rarely developing renal failure. Symptoms usually present in childhood and may include microscopic haematuria, progressive renal failure, bilateral sensorineural deafness, lenticonus, retinitis pigmentosa, and splitting of the lamina densa seen on electron microscopy. In some cases, an Alport’s patient with a failing renal transplant may have anti-GBM antibodies, leading to a Goodpasture’s syndrome-like picture. Diagnosis can be made through molecular genetic testing, renal biopsy, or electron microscopy. In around 85% of cases, the syndrome is inherited in an X-linked dominant pattern, while 10-15% of cases are inherited in an autosomal recessive fashion, with rare autosomal dominant variants existing.
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This question is part of the following fields:
- Renal System
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Question 9
Correct
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A 75-year-old man visits his doctor complaining of weight loss and feeling full quickly. During the abdominal examination, the doctor notices a swollen lymph node in the left supraclavicular region. The doctor suspects that this could be a sign of gastric cancer with the spread of tumor emboli through the thoracic duct as it ascends from the abdomen into the mediastinum. Can you name the two other structures that pass through the diaphragm along with the thoracic duct?
Your Answer: Aorta and azygous vein
Explanation:The point at which the aorta, thoracic duct, and azygous vein cross the diaphragm is at T12, specifically at the aortic opening. This is also where the oesophageal branches of the left gastric veins, the vagal trunk, and the oesophagus pass through the diaphragm, at the oesophageal opening located at T10. The left phrenic nerve and sympathetic trunk have their own separate openings in the diaphragm. A lymph node in the left supraclavicular fossa, known as Virchow’s node, is a characteristic sign of early gastric carcinoma.
Structures Perforating the Diaphragm
The diaphragm is a dome-shaped muscle that separates the thoracic and abdominal cavities. It plays a crucial role in breathing by contracting and relaxing to create negative pressure in the lungs. However, there are certain structures that perforate the diaphragm, allowing them to pass through from the thoracic to the abdominal cavity. These structures include the inferior vena cava at the level of T8, the esophagus and vagal trunk at T10, and the aorta, thoracic duct, and azygous vein at T12.
To remember these structures and their corresponding levels, a helpful mnemonic is I 8(ate) 10 EGGS AT 12. This means that the inferior vena cava is at T8, the esophagus and vagal trunk are at T10, and the aorta, thoracic duct, and azygous vein are at T12. Knowing these structures and their locations is important for medical professionals, as they may need to access or treat them during surgical procedures or diagnose issues related to them.
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This question is part of the following fields:
- Respiratory System
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Question 10
Incorrect
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A sickle cell anaemia patient arrived at the emergency department after taking aspirin. The peripheral blood film revealed bite cells and fragmented red blood cells, while the serum free haemoglobin levels were elevated. Which blood protein would the serum-free haemoglobin bind to?
Your Answer: Transferrin
Correct Answer: Haptoglobin
Explanation:Free haemoglobin is bound by haptoglobin.
Copper is bound by ceruloplasmin.
Stored iron in the body is in the form of ferritin.
Free heme molecules are bound by hemopexin.
Laboratory Findings in Haematological Disease
Haptoglobin is a laboratory test that measures the level of a protein that binds to free haemoglobin. A decrease in haptoglobin levels is often associated with intravascular haemolysis, a condition where red blood cells are destroyed within blood vessels. On the other hand, an increase in mean corpuscular haemoglobin concentration (MCHC) is commonly seen in hereditary spherocytosis and autoimmune haemolytic anemia. In contrast, a decrease in MCHC is often observed in microcytic anaemia, which is commonly caused by iron deficiency. It is important to note that autoimmune haemolytic anemia is often associated with spherocytosis. These laboratory findings are commonly tested in haematological disease exams.
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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 30-year-old man presents to you with complaints of numbness and pain in his hands and feet since this morning. He had visited for gastroenteritis 3 weeks ago. On examination, he has a bilateral reduction in power of 3/5 in his upper and lower limbs. His speech is normal, and he has no other medical conditions. What is the most probable diagnosis?
Your Answer: Raynaud's
Correct Answer: Guillain-Barre syndrome
Explanation:Guillain-Barre syndrome is a condition where the immune system attacks the peripheral nervous system, leading to demyelination. It is often triggered by an infection and presents with rapidly advancing ascending motor neuropathy. Proximal muscles are more affected than distal muscles.
A stroke or transient ischaemic attack usually has a sudden onset and causes unilateral symptoms such as facial droop, arm weakness, and slurred speech.
Raynaud’s disease causes numbness and pain in the fingers and toes, typically in response to cold weather or stress.
Guillain-Barre Syndrome: A Breakdown of its Features
Guillain-Barre syndrome is a condition that occurs when the immune system attacks the peripheral nervous system, resulting in demyelination. This is often triggered by an infection, with Campylobacter jejuni being a common culprit. In the initial stages of the illness, around 65% of patients experience back or leg pain. However, the characteristic feature of Guillain-Barre syndrome is progressive, symmetrical weakness of all limbs, with the legs being affected first in an ascending pattern. Reflexes are reduced or absent, and sensory symptoms tend to be mild. Other features may include a history of gastroenteritis, respiratory muscle weakness, cranial nerve involvement, diplopia, bilateral facial nerve palsy, oropharyngeal weakness, and autonomic involvement, which can lead to urinary retention and diarrhea. Less common findings may include papilloedema, which is thought to be secondary to reduced CSF resorption. To diagnose Guillain-Barre syndrome, a lumbar puncture may be performed, which can reveal a rise in protein with a normal white blood cell count (albuminocytologic dissociation) in 66% of cases. Nerve conduction studies may also be conducted, which can show decreased motor nerve conduction velocity due to demyelination, prolonged distal motor latency, and increased F wave latency.
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This question is part of the following fields:
- Neurological System
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Question 12
Incorrect
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A 55-year-old man presents to the ENT clinic with a 10-week history of progressive dysphagia and a persistent sore throat. He reports no fever or cough, but has lost around 5kg in weight over the past 8 weeks.
During the examination, non-tender palpable cervical lymphadenopathy is observed. Upon oropharyngeal examination, an ill-defined ulcerated lesion is found at the back of the mouth. Biopsies are taken.
What is the most significant risk factor for the likely presentation of this patient?Your Answer: Epstein Barr virus
Correct Answer: Human papillomavirus 16/18
Explanation:Understanding Oncoviruses and Their Associated Cancers
Oncoviruses are viruses that have the potential to cause cancer. These viruses can be detected through blood tests and prevented through vaccination. There are several types of oncoviruses, each associated with a specific type of cancer.
The Epstein-Barr virus, for example, is linked to Burkitt’s lymphoma, Hodgkin’s lymphoma, post-transplant lymphoma, and nasopharyngeal carcinoma. Human papillomavirus 16/18 is associated with cervical cancer, anal cancer, penile cancer, vulval cancer, and oropharyngeal cancer. Human herpes virus 8 is linked to Kaposi’s sarcoma, while hepatitis B and C viruses are associated with hepatocellular carcinoma. Finally, human T-lymphotropic virus 1 is linked to tropical spastic paraparesis and adult T cell leukemia.
It is important to understand the link between oncoviruses and cancer so that appropriate measures can be taken to prevent and treat these diseases. Vaccination against certain oncoviruses, such as HPV, can significantly reduce the risk of developing associated cancers. Regular screening and early detection can also improve outcomes for those who do develop cancer as a result of an oncovirus.
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This question is part of the following fields:
- General Principles
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Question 13
Correct
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A 15-year-old teenage boy comes to see his General Practitioner with swelling in his left scrotum. He reports no pain or other symptoms. During examination in a supine position, the GP notes that the left testicle is smaller than the right and there are no abnormal masses on either side. The GP diagnoses the patient with a varicocele, which is caused by increased hydrostatic pressure in the venous plexus of the left scrotum. The question is, where does the left testicular (gonadal) vein drain into?
Your Answer: Left renal vein
Explanation:The left renal vein receives drainage from the left testicular vein, while the common iliac and internal iliac veins do not receive any blood from the testicles. The internal iliac veins collect blood from the pelvic internal organs and join the external iliac vein, which drains blood from the legs, to form the common iliac vein. On the other hand, the right testicular vein directly drains into the inferior vena cava since it is situated to the right of the midline. The great saphenous veins, which are located superficially, collect blood from the toes.
Scrotal Problems: Epididymal Cysts, Hydrocele, and Varicocele
Epididymal cysts are the most frequent cause of scrotal swellings seen in primary care. They are usually found posterior to the testicle and separate from the body of the testicle. Epididymal cysts may be associated with polycystic kidney disease, cystic fibrosis, or von Hippel-Lindau syndrome. Diagnosis is usually confirmed by ultrasound, and management is typically supportive. However, surgical removal or sclerotherapy may be attempted for larger or symptomatic cysts.
Hydrocele refers to the accumulation of fluid within the tunica vaginalis. They can be communicating or non-communicating. Communicating hydroceles are common in newborn males and usually resolve within the first few months of life. Non-communicating hydroceles are caused by excessive fluid production within the tunica vaginalis. Hydroceles may develop secondary to epididymo-orchitis, testicular torsion, or testicular tumors. Diagnosis may be clinical, but ultrasound is required if there is any doubt about the diagnosis or if the underlying testis cannot be palpated. Management depends on the severity of the presentation, and further investigation, such as ultrasound, is usually warranted to exclude any underlying cause such as a tumor.
Varicocele is an abnormal enlargement of the testicular veins. They are usually asymptomatic but may be important as they are associated with infertility. Varicoceles are much more common on the left side and are classically described as a bag of worms. Diagnosis is made through ultrasound with Doppler studies. Management is usually conservative, but occasionally surgery is required if the patient is troubled by pain. There is ongoing debate regarding the effectiveness of surgery to treat infertility.
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This question is part of the following fields:
- Renal System
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Question 14
Incorrect
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A 22-year-old man is discovered unresponsive in his apartment after intentionally overdosing on barbiturates. He is rushed to the hospital with sirens blaring.
Upon being transported, he awakens and is evaluated with a Glasgow Coma Scale (GCS) score of 11 (E3V3M5).
What is the primary type of ion channel that this medication targets to produce its sedative properties?Your Answer: Calcium
Correct Answer: Chloride
Explanation:Barbiturates prolong the opening of chloride channels
Barbiturates are strong sedatives that have been used in the past as anesthetics and anti-epileptic drugs. They work in the central nervous system by binding to a subunit of the GABA receptor, which opens chloride channels. This results in an influx of chloride ions and hyperpolarization of the neuronal resting potential.
The passage of calcium, magnesium, potassium, and sodium ions through channels, both actively and passively, is crucial for neuronal and peripheral function and is also targeted by other pharmacological agents.
Barbiturates are commonly used in the treatment of anxiety and seizures, as well as for inducing anesthesia. They work by enhancing the action of GABAA, a neurotransmitter that helps to calm the brain. Specifically, barbiturates increase the duration of chloride channel opening, which allows more chloride ions to enter the neuron and further inhibit its activity. This is in contrast to benzodiazepines, which increase the frequency of chloride channel opening. A helpful mnemonic to remember this difference is Frequently Bend – During Barbeque or Barbiturates increase duration & Benzodiazepines increase frequency. Overall, barbiturates are an important class of drugs that can help to manage a variety of conditions by modulating the activity of GABAA in the brain.
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This question is part of the following fields:
- Neurological System
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Question 15
Correct
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A 15-year-old girl presents with difficulty breathing and is unable to speak in full sentences due to panic. She has a history of asthma. Upon examination, her respiratory rate is 28 breaths/minute, heart rate is 105 beats/minute, and her chest is silent. What is the most concerning feature in this girl's history?
Your Answer: Silent chest
Explanation:Identify the life-threatening features of an asthma attack.
Assessing the severity of asthma attacks in children is crucial for effective management. The 2016 BTS/SIGN guidelines provide criteria for assessing the severity of asthma in general practice. These criteria include measuring SpO2 levels, PEF (peak expiratory flow) rates, heart rate, respiratory rate, use of accessory neck muscles, and other symptoms such as breathlessness, agitation, altered consciousness, and cyanosis.
A severe asthma attack is characterized by a SpO2 level below 92%, PEF rates between 33-50% of the best or predicted, being too breathless to talk or feed, and a high heart and respiratory rate. On the other hand, a life-threatening asthma attack is indicated by a SpO2 level below 92%, PEF rates below 33% of the best or predicted, a silent chest, poor respiratory effort, use of accessory neck muscles, agitation, altered consciousness, and cyanosis.
It is important for healthcare professionals to be familiar with these criteria to ensure prompt and appropriate management of asthma attacks in children. Early recognition of the severity of an asthma attack can help prevent complications and reduce the risk of hospitalization or death.
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This question is part of the following fields:
- Respiratory System
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Question 16
Incorrect
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A 75-year-old man presents to the emergency department with acute chest pain that is radiating to his left shoulder. He has a medical history of a previous transient ischaemic attack three years ago and is currently taking aspirin 75mg OD.
Upon initial assessment, an ECG reveals ST-segment elevation in V1-V3. The patient undergoes percutaneous coronary intervention with a drug-eluting stent and is stable post-procedure. His treatment plan includes ramipril, ticagrelor, simvastatin, and atenolol.
What is the mechanism of action of the newly prescribed antiplatelet medication?Your Answer: Inhibit phosphodiesterase
Correct Answer: Inhibit the binding of ADP to platelets
Explanation:Ticagrelor and clopidogrel have a similar mechanism of action in inhibiting ADP binding to platelet receptors, which prevents platelet aggregation. In patients with STEMI who undergo percutaneous coronary intervention with a drug-eluting stent, dual antiplatelet therapy, beta-blockers, ACE inhibitors, and anti-hyperlipidemic drugs are commonly used for secondary management.
Glycoprotein IIb/IIIa complex is a fibrinogen receptor found on platelets that, when activated, leads to platelet aggregation. Glycoprotein IIb/IIIa inhibitors, such as abciximab, bind to this receptor and prevent ligands like fibrinogen from accessing their binding site. Glycoprotein IIb/IIIa antagonists, like eptifibatide, compete with ligands for the receptor’s binding site, blocking the formation of thrombi.
Dipyridamole inhibits platelet cAMP-phosphodiesterase, leading to increased intra-platelet cAMP and decreased arachidonic acid release, resulting in reduced thromboxane A2 formation. It also inhibits adenosine reuptake by vascular endothelial cells and erythrocytes, leading to increased adenosine concentration, activation of adenyl cyclase, and increased cAMP production.
ADP receptor inhibitors, such as clopidogrel, prasugrel, ticagrelor, and ticlopidine, work by inhibiting the P2Y12 receptor, which leads to sustained platelet aggregation and stabilization of the platelet plaque. Clinical trials have shown that prasugrel and ticagrelor are more effective than clopidogrel in reducing short- and long-term ischemic events in high-risk patients with acute coronary syndrome or undergoing percutaneous coronary intervention. However, ticagrelor may cause dyspnea due to impaired clearance of adenosine, and there are drug interactions and contraindications to consider for each medication. NICE guidelines recommend dual antiplatelet treatment with aspirin and ticagrelor for 12 months as a secondary prevention strategy for ACS.
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This question is part of the following fields:
- Cardiovascular System
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Question 17
Correct
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A 70-year-old individual presents to the ophthalmology clinic with a gradual decline in visual acuity, difficulty seeing at night, and occasional floaters. Upon fundoscopy, yellow pigment deposits are observed in the macular region, along with demarcated red patches indicating fluid leakage and bleeding. The patient has no significant medical history. The ophthalmologist recommends a treatment that directly inhibits vascular endothelial growth factors. What is the appropriate management for this patient?
Your Answer: Bevacizumab
Explanation:Bevacizumab is a monoclonal antibody that targets vascular endothelial growth factor (VEGF) and is used as a first-line treatment for the neovascular or exudative form of age-related macular degeneration (AMD). This form of AMD is characterized by the proliferation of abnormal blood vessels in the eye that leak blood and protein below the macula, causing damage to the photoreceptors. Bevacizumab blocks VEGF, which stimulates the growth of these abnormal vessels.
Fluocinolone is a corticosteroid that is used as an anti-inflammatory via intraocular injection in some eye conditions, but it does not affect VEGF. Laser photocoagulation is used to cauterize ocular blood vessels in several eye conditions, but it also does not affect VEGF. Verteporfin is a medication used as a photosensitizer prior to photodynamic therapy, which can be used in eye conditions with ocular vessel proliferation, but it is not an anti-VEGF drug.
Age-related macular degeneration (ARMD) is a common cause of blindness in the UK, characterized by degeneration of the central retina (macula) and the formation of drusen. The risk of ARMD increases with age, smoking, family history, and conditions associated with an increased risk of ischaemic cardiovascular disease. ARMD is classified into dry and wet forms, with the latter carrying the worst prognosis. Clinical features include subacute onset of visual loss, difficulties in dark adaptation, and visual hallucinations. Signs include distortion of line perception, the presence of drusen, and well-demarcated red patches in wet ARMD. Investigations include slit-lamp microscopy, colour fundus photography, fluorescein angiography, indocyanine green angiography, and ocular coherence tomography. Treatment options include a combination of zinc with anti-oxidant vitamins for dry ARMD and anti-VEGF agents for wet ARMD. Laser photocoagulation is also an option, but anti-VEGF therapies are usually preferred.
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This question is part of the following fields:
- Neurological System
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Question 18
Incorrect
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A 68-year-old woman comes into the emergency department with her daughter after experiencing shortness of breath for 2 hours. She is in poor condition with a heart rate of 128/min, blood pressure of 90/66 mmHg, O2 saturation of 94% on air, respiratory rate of 29/min, and temperature of 36.3ÂșC. Her legs are swollen up to her knees, and her JVP is visible at her ear lobe. She has a history of myocardial infarction 4 years ago, angina, and a smoking history of 20 packs per year.
What is the underlying cause of her presentation?Your Answer: Reduced ventilation/ perfusion due to pulmonary oedema
Correct Answer: Reduced cardiac output
Explanation:The cause of the patient’s acute heart failure is a decrease in cardiac output, which may be due to biventricular failure. This is evidenced by peripheral edema and respiratory distress, including shortness of breath, high respiratory rate, and low oxygen saturation. These symptoms are likely caused by inadequate heart filling, leading to peripheral congestion and pulmonary edema or pleural effusion.
The pathophysiology of myocardial infarction is not relevant to the patient’s condition, as it is not explained by her peripheral edema and elevated JVP.
While shortness of breath in heart failure may be caused by reduced ventilation/perfusion due to pulmonary edema, this is only one symptom and not the underlying mechanism of the condition.
The overactivity of the renin-angiotensin system is a physiological response to decreased blood pressure or increased renal sympathetic firing, but it is not necessarily related to the patient’s current condition.
Understanding Acute Heart Failure: Symptoms and Diagnosis
Acute heart failure (AHF) is a medical emergency that can occur suddenly or worsen over time. It can affect individuals with or without a history of pre-existing heart failure. Decompensated AHF is more common and is characterized by a background history of HF. AHF is typically caused by a reduced cardiac output resulting from a functional or structural abnormality. De-novo heart failure, on the other hand, is caused by increased cardiac filling pressures and myocardial dysfunction, usually due to ischaemia.
The most common precipitating causes of acute AHF are acute coronary syndrome, hypertensive crisis, acute arrhythmia, and valvular disease. Patients with heart failure may present with signs of fluid congestion, weight gain, orthopnoea, and breathlessness. They are broadly classified into four groups based on whether they present with or without hypoperfusion and fluid congestion. This classification is clinically useful in determining the therapeutic approach.
The symptoms of AHF include breathlessness, reduced exercise tolerance, oedema, fatigue, chest signs, and an S3-heart sound. Signs of AHF include cyanosis, tachycardia, elevated jugular venous pressure, and a displaced apex beat. Over 90% of patients with AHF have a normal or increased blood pressure.
The diagnostic workup for patients with AHF includes blood tests, chest X-ray, echocardiogram, and B-type natriuretic peptide. Blood tests are used to identify any underlying abnormalities, while chest X-ray findings include pulmonary venous congestion, interstitial oedema, and cardiomegaly. Echocardiogram is used to identify pericardial effusion and cardiac tamponade, while raised levels of B-type natriuretic peptide (>100mg/litre) indicate myocardial damage and support the diagnosis.
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This question is part of the following fields:
- Cardiovascular System
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Question 19
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An 80-year-old man is recuperating after undergoing a right total hip replacement. During a session with the physiotherapists, it is observed that his right foot is dragging on the ground while walking.
Upon conducting a neurological examination of his lower limbs, it is found that his left leg is completely normal. However, his right leg has 0/5 power of dorsiflexion and knee flexion, a reduced ankle and plantar reflex, and no sensation over the lateral calf, sole, and dorsum of the foot.
What is the nerve lesion that has occurred?Your Answer: Tibial nerve
Correct Answer: Sciatic nerve
Explanation:Foot drop can be caused by a lesion to the sciatic nerve.
When the sciatic nerve is damaged, it can result in various symptoms such as foot drop, loss of power below the knee, loss of knee flexion, loss of ankle jerk and plantar response. The sciatic nerve innervates the hamstring muscles in the posterior thigh and indirectly innervates other muscles via its two terminal branches: the tibial nerve and the common fibular nerve. The tibial nerve supplies the calf muscles and some intrinsic muscles of the foot, while the common fibular nerve supplies the muscles of the anterior and lateral leg, as well as the remaining intrinsic foot muscles. Although the sciatic nerve has no direct sensory inputs, it receives information from its two terminal branches, which supply the skin of various areas of the leg and foot.
Sciatic nerve lesions can occur due to various reasons, such as neck of femur fractures and total hip replacement trauma. However, it is important to note that a femoral nerve lesion would cause different symptoms, such as weakness in anterior thigh muscles, reduced hip flexion and knee extension, and loss of sensation to the anteromedial thigh and medial leg and foot. Similarly, lesions to the lower gluteal nerve or superior gluteal nerve would cause weakness in specific muscles and no sensory loss.
Understanding Foot Drop: Causes and Examination
Foot drop is a condition that occurs when the foot dorsiflexors become weak. This can be caused by various factors, including a common peroneal nerve lesion, L5 radiculopathy, sciatic nerve lesion, superficial or deep peroneal nerve lesion, or central nerve lesions. However, the most common cause is a common peroneal nerve lesion, which is often due to compression at the neck of the fibula. This can be triggered by certain positions, prolonged confinement, recent weight loss, Baker’s cysts, or plaster casts to the lower leg.
To diagnose foot drop, a thorough examination is necessary. If the patient has an isolated peroneal neuropathy, there will be weakness of foot dorsiflexion and eversion, and reflexes will be normal. Weakness of hip abduction is suggestive of an L5 radiculopathy. Bilateral symptoms, fasciculations, or other abnormal neurological findings are indications for specialist referral.
If foot drop is diagnosed, conservative management is appropriate. Patients should avoid leg crossing, squatting, and kneeling. Symptoms typically improve over 2-3 months.
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This question is part of the following fields:
- Neurological System
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Question 20
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A 55-year-old male presents with exertional fatigue. He has no significant past medical history and is not taking any medications. His blood test results show abnormal readings of Hb 125 g/L (normal range: 135-180 g/L) and calcium 2.9 mmol/L (normal range: 2.1-2.6 mmol/L). The rest of his blood test results, including mean corpuscular volume, platelet count, and white cell count, are normal. Additionally, his serum ferritin, vitamin B12, and folic acid levels are normal. Upon conducting a urine protein electrophoresis, the presence of immunoglobulin light chains is detected. What is the most likely diagnosis?
Your Answer: Acute interstitial nephritis
Correct Answer: Multiple myeloma
Explanation:The diagnosis of multiple myeloma can be supported by the presence of Bence-Jones protein, which is a monoclonal globulin protein produced by neoplastic plasma cells. Anaemia and hypercalcemia, along with the presence of Bence-Jones protein in the urine, make multiple myeloma the most likely diagnosis.
Gout can be diagnosed by examining the contents of a joint fluid aspirate under polarised red light. The urate crystals will appear needle-shaped and negatively birefringent.
Megaloblastic anaemia occurs due to inhibition of DNA synthesis during red blood cell production. A normal mean corpuscular volume (MCV) and serum vitamin B12 level can rule out megaloblastic anaemia.
While patients with non-Hodgkin lymphoma may present with anaemia, it can be ruled out for the time being as the white cell count and platelet count are normal.
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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