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  • Question 1 - A 28-year-old man is found on his bathroom floor next to needles and...

    Incorrect

    • A 28-year-old man is found on his bathroom floor next to needles and syringes and is brought into the hospital. He has a Glasgow coma score of 10 and a bedside oxygen saturation of 88%. On physical examination, he has pinpoint pupils and needle track marks on his left arm. His arterial blood gases are as follows: PaO2 7.4 kPa (11.3-12.6), PaCO2 9.6 kPa (4.7-6.0), pH 7.32 (7.36-7.44), and HCO3 25 mmol/L (20-28). What do these results indicate?

      Your Answer: Acute type I respiratory failure

      Correct Answer: Acute type II respiratory failure

      Explanation:

      Opiate Overdose

      Opiate overdose is a common occurrence that can lead to slowed breathing, inadequate oxygen saturation, and CO2 retention. This classic picture of opiate overdose can be reversed with the use of naloxone. The condition is often caused by the use of illicit drugs and can have serious consequences if left untreated.

    • This question is part of the following fields:

      • Respiratory System
      81.2
      Seconds
  • Question 2 - Which of the following structures separates the ulnar artery from the median nerve?...

    Incorrect

    • Which of the following structures separates the ulnar artery from the median nerve?

      Your Answer: Tendon of biceps brachii

      Correct Answer: Pronator teres

      Explanation:

      It is located deeply to the pronator teres muscle, which creates a separation from the median nerve.

      Anatomy of the Ulnar Artery

      The ulnar artery is a blood vessel that begins in the middle of the antecubital fossa and runs obliquely downward towards the ulnar side of the forearm. It then follows the ulnar border to the wrist, where it crosses over the flexor retinaculum and divides into the superficial and deep volar arches. The artery is deep to the pronator teres, flexor carpi radialis, and palmaris longus muscles, and lies on the brachialis and flexor digitorum profundus muscles. At the wrist, it is superficial to the flexor retinaculum.

      The ulnar nerve runs medially to the lower two-thirds of the artery, while the median nerve is in relation with the medial side of the artery for about 2.5 cm before crossing over it. The artery also gives off a branch called the anterior interosseous artery.

      Understanding the anatomy of the ulnar artery is important for medical professionals, as it plays a crucial role in the blood supply to the forearm and hand.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
      52.7
      Seconds
  • Question 3 - A 47-year-old patient visits his doctor complaining of a cough, fever and coryzal...

    Correct

    • A 47-year-old patient visits his doctor complaining of a cough, fever and coryzal symptoms. The doctor notes a temperature of 38.1ºC. What is the primary effector responsible for these symptoms?

      Your Answer: IL-1

      Explanation:

      IL-1 is primarily responsible for inducing fever, which is likely the cause of the patient’s fever in the context of an upper respiratory tract infection. This cytokine is produced by macrophages as part of the acute inflammatory response. Other cytokines, such as IL-5 and IL-8, have different functions, such as eosinophil activation and neutrophil chemotaxis, respectively. However, they are not the main effector responsible for the fever in this case. Additionally, von Willebrand factor is a blood glycoprotein that plays a crucial role in primary and secondary haemostasis.

      Overview of Cytokines and Their Functions

      Cytokines are signaling molecules that play a crucial role in the immune system. Interleukins are a type of cytokine that are produced by various immune cells and have specific functions. IL-1, produced by macrophages, induces acute inflammation and fever. IL-2, produced by Th1 cells, stimulates the growth and differentiation of T cell responses. IL-3, produced by activated T helper cells, stimulates the differentiation and proliferation of myeloid progenitor cells. IL-4, produced by Th2 cells, stimulates the proliferation and differentiation of B cells. IL-5, also produced by Th2 cells, stimulates the production of eosinophils. IL-6, produced by macrophages and Th2 cells, stimulates the differentiation of B cells and induces fever. IL-8, produced by macrophages, promotes neutrophil chemotaxis. IL-10, produced by Th2 cells, inhibits Th1 cytokine production and is known as an anti-inflammatory cytokine. IL-12, produced by dendritic cells, macrophages, and B cells, activates NK cells and stimulates the differentiation of naive T cells into Th1 cells.

      In addition to interleukins, there are other cytokines with specific functions. Tumor necrosis factor-alpha, produced by macrophages, induces fever and promotes neutrophil chemotaxis. Interferon-gamma, produced by Th1 cells, activates macrophages. Understanding the functions of cytokines is important in developing treatments for various immune-related diseases.

    • This question is part of the following fields:

      • General Principles
      8.1
      Seconds
  • Question 4 - An 82-year-old man arrives at the emergency department with sepsis of unknown origin....

    Incorrect

    • An 82-year-old man arrives at the emergency department with sepsis of unknown origin. During a thorough examination, it is discovered that his big toe is swollen, black, and tender. A fluid collection is also present at the nail bed. The patient has a history of uncontrolled type 1 diabetes mellitus. An MRI confirms the diagnosis of osteomyelitis. What is the probable causative organism?

      Your Answer: Streptococcus pyogenes

      Correct Answer: Staphylococcus aureus

      Explanation:

      The most common cause of osteomyelitis is Staphylococcus aureus, a bacteria that is normally found on the skin and mucus membranes but can become pathogenic in individuals who are immunocompromised or have risk factors for infections. Clostridium perfringens, Pseudomonas aeruginosa, and Staphylococcus epidermidis are not common causes of osteomyelitis, although they may cause other types of infections.

      Understanding Osteomyelitis: Types, Causes, and Treatment

      Osteomyelitis is a bone infection that can be classified into two types: haematogenous and non-haematogenous. Haematogenous osteomyelitis is caused by bacteria in the bloodstream and is usually monomicrobial. It is more common in children and can be caused by risk factors such as sickle cell anaemia, intravenous drug use, immunosuppression, and infective endocarditis. On the other hand, non-haematogenous osteomyelitis is caused by the spread of infection from adjacent soft tissues or direct injury to the bone. It is often polymicrobial and more common in adults, with risk factors such as diabetic foot ulcers, pressure sores, diabetes mellitus, and peripheral arterial disease.

      Staphylococcus aureus is the most common cause of osteomyelitis, except in patients with sickle-cell anaemia where Salmonella species are more prevalent. To diagnose osteomyelitis, MRI is the imaging modality of choice, with a sensitivity of 90-100%.

      The treatment for osteomyelitis involves a course of antibiotics for six weeks. Flucloxacillin is the preferred antibiotic, but clindamycin can be used for patients who are allergic to penicillin. Understanding the types, causes, and treatment of osteomyelitis is crucial in managing this bone infection.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
      31.8
      Seconds
  • Question 5 - A 45-year-old patient is visiting the metabolic disorders clinic and has been diagnosed...

    Correct

    • A 45-year-old patient is visiting the metabolic disorders clinic and has been diagnosed with Refsum disease, a condition that causes the inability to break down phytanic acid, a long-chain fatty acid. Which organelle in the cell is typically responsible for the breakdown of this substance?

      Your Answer: Peroxisomes

      Explanation:

      Peroxisomes are responsible for breaking down long chain fatty acids, as they contain oxidative enzymes such as catalase and urate oxidase. Refsum disease is caused by a missing enzyme called phytanoyl-CoA hydroxylase. Lysosomes break down waste products, while the nucleus protects the cell’s genetic material and regulates protein entry and exit. The rough endoplasmic reticulum translates mRNA into proteins, while the smooth endoplasmic reticulum synthesizes and stores lipids, particularly in liver cells.

      Functions of Cell Organelles

      The functions of major cell organelles can be summarized in a table. The rough endoplasmic reticulum (RER) is responsible for the translation and folding of new proteins, as well as the manufacture of lysosomal enzymes. It is also the site of N-linked glycosylation. Cells such as pancreatic cells, goblet cells, and plasma cells have extensive RER. On the other hand, the smooth endoplasmic reticulum (SER) is involved in steroid and lipid synthesis. Cells of the adrenal cortex, hepatocytes, and reproductive organs have extensive SER.

      The Golgi apparatus modifies, sorts, and packages molecules that are destined for cell secretion. The addition of mannose-6-phosphate to proteins designates transport to lysosome. The mitochondrion is responsible for aerobic respiration and contains mitochondrial genome as circular DNA. The nucleus is involved in DNA maintenance, RNA transcription, and RNA splicing, which removes the non-coding sequences of genes (introns) from pre-mRNA and joins the protein-coding sequences (exons).

      The lysosome is responsible for the breakdown of large molecules such as proteins and polysaccharides. The nucleolus produces ribosomes, while the ribosome translates RNA into proteins. The peroxisome is involved in the catabolism of very long chain fatty acids and amino acids, resulting in the formation of hydrogen peroxide. Lastly, the proteasome, along with the lysosome pathway, is involved in the degradation of protein molecules that have been tagged with ubiquitin.

    • This question is part of the following fields:

      • General Principles
      22.3
      Seconds
  • Question 6 - You are participating in a seminar about eating disorders. What renal alteration is...

    Incorrect

    • You are participating in a seminar about eating disorders. What renal alteration is common in individuals with extreme malnourishment?

      Your Answer: Increase in serum urea

      Correct Answer: Reduced glomerular filtration rate

      Explanation:

      Renal Physiology Changes in Severe Malnutrition

      Patients with severe malnutrition experience changes in their renal physiology due to reduced food intake. These changes include an increased secretion of aldosterone and a reduced glomerular filtration rate (GFR), which alters the excretion patterns of many solutes, electrolytes, and drugs. As a result, there is an increased urinary excretion of potassium, calcium, magnesium, and phosphate, leading to a tendency for hypokalaemia, hypocalcaemia, hypomagnesaemia, and hypophosphataemia over time.

      Furthermore, the reduced muscle bulk in individuals with severe malnutrition causes low levels of production of urea and creatinine. However, reduced excretion causes plasma levels to remain normal or only slightly reduced. As muscle is broken down to provide substrates for gluconeogenesis, a negative nitrogen balance ensues. Additionally, urate excretion is reduced, causing a relative hyperuricaemia.

      In summary, severe malnutrition affects renal physiology, leading to altered excretion patterns of various solutes, electrolytes, and drugs. These changes can result in imbalances in potassium, calcium, magnesium, and phosphate levels. Furthermore, the breakdown of muscle tissue can cause a negative nitrogen balance, while reduced urate excretion can lead to hyperuricaemia.

    • This question is part of the following fields:

      • Clinical Sciences
      64.3
      Seconds
  • Question 7 - A 45-year-old female is admitted to the hospital for investigation of recently developed...

    Correct

    • A 45-year-old female is admitted to the hospital for investigation of recently developed hypertension, myalgia, and a facial rash. She experiences a decline in kidney function and complains of muscle aches and ankle swelling during her hospital stay. A kidney biopsy and urine sample are taken, revealing a proliferative 'wire-loop' glomerular lesion on histopathological assessment. The urinalysis shows proteinuria but no presence of leukocytes or nitrites. What is the most probable diagnosis?

      Your Answer: Systemic lupus erythematosus

      Explanation:

      Lupus nephritis is characterized by proliferative ‘wire-loop’ glomerular histology, proteinuria, and systemic symptoms. This condition occurs when autoimmune processes in SLE cause inflammation and damage to the glomeruli. Symptoms may include oedema, myalgia, arthralgia, hypertension, and foamy-appearing urine due to high levels of protein. Acute tubular necrosis primarily affects the tubules and does not typically present with proteinuria. Congestive heart failure and IgA nephropathy can cause proteinuria, but they do not result in the ‘wire-loop’ glomerular lesion seen in lupus nephritis. Pyelonephritis may also cause proteinuria, but it is an infectious process and would present with additional symptoms such as nitrites, leukocytes, and blood in the urine.

      Renal Complications in Systemic Lupus Erythematosus

      Systemic lupus erythematosus (SLE) can lead to severe renal complications, including lupus nephritis, which can result in end-stage renal disease. Regular check-ups with urinalysis are necessary to detect proteinuria in SLE patients. The WHO classification system categorizes lupus nephritis into six classes, with class IV being the most common and severe form. Renal biopsy shows characteristic findings such as endothelial and mesangial proliferation, a wire-loop appearance, and subendothelial immune complex deposits.

      Management of lupus nephritis involves treating hypertension and using glucocorticoids with either mycophenolate or cyclophosphamide for initial therapy in cases of focal (class III) or diffuse (class IV) lupus nephritis. Mycophenolate is generally preferred over azathioprine for subsequent therapy to decrease the risk of developing end-stage renal disease. Early detection and proper management of renal complications in SLE patients are crucial to prevent irreversible damage to the kidneys.

    • This question is part of the following fields:

      • Renal System
      51.5
      Seconds
  • Question 8 - A 26-year-old woman has recently begun her career as a graphic designer. Her...

    Incorrect

    • A 26-year-old woman has recently begun her career as a graphic designer. Her partner has observed that she spends extensive amounts of time working on what she believes will be the most innovative design project ever created that will transform the industry. Despite acknowledging that she may not succeed, she remains highly motivated. How would you describe her thought process?

      Your Answer: Grandiose delusion

      Correct Answer: Overvalued idea

      Explanation:

      Overvalued Ideas

      An overvalued idea is a comprehensible and acceptable belief that dominates a person’s life and preoccupies their mind. It is not a delusion, and the person acknowledges the possibility that their belief may or may not be true. However, they pursue their aim with an overwhelming desire. Despite the intensity of their belief, the person remains functioning, and there is no evidence of psychotic symptoms.

      According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), an overvalued idea is an unreasonable and sustained belief that is maintained with less than delusional intensity. This means that the person is aware that their belief may not be accepted by others in their culture or subculture.

      In summary, an overvalued idea is a strong belief that is not firmly fixed as true, but still dominates a person’s life. It is not a delusion, and the person remains functioning. overvalued ideas is important in distinguishing them from delusions and other mental health conditions.

    • This question is part of the following fields:

      • Psychiatry
      27.8
      Seconds
  • Question 9 - A 65-year-old woman is admitted to the ICU with a multidrug-resistant urinary tract...

    Correct

    • A 65-year-old woman is admitted to the ICU with a multidrug-resistant urinary tract infection. She has a medical history of type 2 diabetes, hypertension, and a previous cerebrovascular accident. After three days, she experiences an altered sensorium and her urine output has been 100 ml over the past 12 hours. Her creatinine level has increased from 1 mg/dl to almost 5 mg/dl, and her blood pressure is currently 180/100 mmHg. The patient is currently taking amikacin, insulin, atorvastatin, atenolol, ramipril, and clopidogrel.

      Which medication, other than ramipril, should be discontinued for this patient?

      Your Answer: Amikacin

      Explanation:

      The patient’s symptoms suggest that they may be experiencing acute kidney injury (AKI) as a result of a severe urinary tract infection and potential sepsis. It is important to note that ACE inhibitors such as ramipril should not be used in cases of AKI, and aminoglycosides like amikacin should also be discontinued. Beta-blockers like atenolol, on the other hand, are generally safe to use in AKI patients and may be preferred over ACE inhibitors and ARBs as antihypertensives. While statins like atorvastatin are generally safe in AKI, they can rarely cause rhabdomyolysis, which can worsen renal function and lead to renal failure. Therefore, patients who experience muscle pain should be evaluated further to rule out the possibility of rhabdomyolysis.

      Acute kidney injury (AKI) is a condition where there is a reduction in renal function following an insult to the kidneys. It was previously known as acute renal failure and can result in long-term impaired kidney function or even death. AKI can be caused by prerenal, intrinsic, or postrenal factors. Patients with chronic kidney disease, other organ failure/chronic disease, a history of AKI, or who have used drugs with nephrotoxic potential are at an increased risk of developing AKI. To prevent AKI, patients at risk may be given IV fluids or have certain medications temporarily stopped.

      The kidneys are responsible for maintaining fluid balance and homeostasis, so a reduced urine output or fluid overload may indicate AKI. Symptoms may not be present in early stages, but as renal failure progresses, patients may experience arrhythmias, pulmonary and peripheral edema, or features of uraemia. Blood tests such as urea and electrolytes can be used to detect AKI, and urinalysis and imaging may also be necessary.

      Management of AKI is largely supportive, with careful fluid balance and medication review. Loop diuretics and low-dose dopamine are not recommended, but hyperkalaemia needs prompt treatment to avoid life-threatening arrhythmias. Renal replacement therapy may be necessary in severe cases. Patients with suspected AKI secondary to urinary obstruction require prompt review by a urologist, and specialist input from a nephrologist is required for cases where the cause is unknown or the AKI is severe.

    • This question is part of the following fields:

      • Renal System
      54
      Seconds
  • Question 10 - A 45-year-old woman visits her doctor complaining of muscle cramps and fatigue. Upon...

    Correct

    • A 45-year-old woman visits her doctor complaining of muscle cramps and fatigue. Upon ruling out any musculoskeletal issues, a blood test is conducted which reveals hyperparathyroidism and low serum phosphate levels. It is suspected that the low phosphate levels are due to the inhibitory effect of parathyroid hormone on renal phosphate reabsorption. Which site in the kidney is most likely affected by parathyroid hormone to cause these blood results?

      Your Answer: Proximal convoluted tubule

      Explanation:

      The proximal convoluted tubule is responsible for the majority of renal phosphate reabsorption. This occurs through co-transport with sodium and up to two thirds of filtered water. The thin ascending limb of the Loop of Henle is impermeable to water but highly permeable to sodium and chloride, while reabsorption of these ions occurs in the thick ascending limb. Parathyroid hormone is most effective at the proximal convoluted tubule due to its role in regulating phosphate reabsorption.

      The Loop of Henle and its Role in Renal Physiology

      The Loop of Henle is a crucial component of the renal system, located in the juxtamedullary nephrons and running deep into the medulla. Approximately 60 litres of water containing 9000 mmol sodium enters the descending limb of the loop of Henle in 24 hours. The osmolarity of fluid changes and is greatest at the tip of the papilla. The thin ascending limb is impermeable to water, but highly permeable to sodium and chloride ions. This loss means that at the beginning of the thick ascending limb the fluid is hypo osmotic compared with adjacent interstitial fluid. In the thick ascending limb, the reabsorption of sodium and chloride ions occurs by both facilitated and passive diffusion pathways. The loops of Henle are co-located with vasa recta, which have similar solute compositions to the surrounding extracellular fluid, preventing the diffusion and subsequent removal of this hypertonic fluid. The energy-dependent reabsorption of sodium and chloride in the thick ascending limb helps to maintain this osmotic gradient. Overall, the Loop of Henle plays a crucial role in regulating the concentration of solutes in the renal system.

    • This question is part of the following fields:

      • Renal System
      37.6
      Seconds
  • Question 11 - A 65-year-old man was brought to the emergency department due to a respiratory...

    Correct

    • A 65-year-old man was brought to the emergency department due to a respiratory infection. After receiving antibiotics and showing signs of improvement, he suddenly collapsed before being released. An ECG was performed and revealed fast, irregular QRS complexes that seemed to be twisting around the baseline.

      Which antibiotic is the probable culprit for the aforementioned situation?

      Your Answer: Clarithromycin

      Explanation:

      Torsades de pointes can be caused by macrolides

      The probable reason for the patient’s collapse is torsades de pointes, which is identified by fast, irregular QRS complexes that seem to be ‘twisting’ around the baseline on the ECG. This condition is linked to a prolonged QT interval. In this instance, the QT interval was prolonged due to the use of clarithromycin, a macrolide antibiotic. None of the other medications have been found to prolong the QT interval.

      Torsades de pointes is a type of ventricular tachycardia that is associated with a prolonged QT interval. This condition can lead to ventricular fibrillation and sudden death. There are several causes of a long QT interval, including congenital conditions such as Jervell-Lange-Nielsen syndrome and Romano-Ward syndrome, as well as certain medications like amiodarone, tricyclic antidepressants, and antipsychotics. Other factors that can contribute to a long QT interval include electrolyte imbalances, myocarditis, hypothermia, and subarachnoid hemorrhage. The management of torsades de pointes typically involves the administration of intravenous magnesium sulfate.

    • This question is part of the following fields:

      • Cardiovascular System
      100.3
      Seconds
  • Question 12 - A 55-year-old man with a history of diabetes visits his ophthalmologist for his...

    Correct

    • A 55-year-old man with a history of diabetes visits his ophthalmologist for his yearly diabetic retinopathy screening. During the examination, the physician observes venous beading. What other clinical manifestation would be present due to the same underlying pathophysiology?

      Your Answer: Cotton wool spots

      Explanation:

      Cotton wool spots found in diabetic retinopathy are indicative of retinal infarction resulting from ischemic disruption. Venous beading, on the other hand, is characterized by irregular constriction and dilation of venules in the retina due to retinal ischemia. It is important to note that cupping of the optic disc is not associated with diabetic retinopathy but rather with open-angle glaucoma. Similarly, lipid exudates are not a feature of diabetic retinopathy as they occur at the border between thickened and non-thickened retina, resulting in extravasated lipoprotein.

      Understanding Diabetic Retinopathy

      Diabetic retinopathy is a leading cause of blindness in adults aged 35-65 years-old. The condition is caused by hyperglycaemia, which leads to abnormal metabolism in the retinal vessel walls, causing damage to endothelial cells and pericytes. This damage leads to increased vascular permeability, which causes exudates seen on fundoscopy. Pericyte dysfunction predisposes to the formation of microaneurysms, while neovascularization is caused by the production of growth factors in response to retinal ischaemia.

      Patients with diabetic retinopathy are typically classified into those with non-proliferative diabetic retinopathy (NPDR), proliferative retinopathy (PDR), and maculopathy. NPDR is further classified into mild, moderate, and severe, depending on the presence of microaneurysms, blot haemorrhages, hard exudates, cotton wool spots, venous beading/looping, and intraretinal microvascular abnormalities. PDR is characterized by retinal neovascularization, which may lead to vitreous haemorrhage, and fibrous tissue forming anterior to the retinal disc. Maculopathy is based on location rather than severity and is more common in Type II DM.

      Management of diabetic retinopathy involves optimizing glycaemic control, blood pressure, and hyperlipidemia, as well as regular review by ophthalmology. For maculopathy, intravitreal vascular endothelial growth factor (VEGF) inhibitors are used if there is a change in visual acuity. Non-proliferative retinopathy is managed through regular observation, while severe/very severe cases may require panretinal laser photocoagulation. Proliferative retinopathy is treated with panretinal laser photocoagulation, intravitreal VEGF inhibitors, and vitreoretinal surgery in severe or vitreous haemorrhage cases. Examples of VEGF inhibitors include ranibizumab, which has a strong evidence base for slowing the progression of proliferative diabetic retinopathy and improving visual acuity.

    • This question is part of the following fields:

      • Neurological System
      50.6
      Seconds
  • Question 13 - What medication enhances the body's metabolic rate? ...

    Correct

    • What medication enhances the body's metabolic rate?

      Your Answer: Thyroxine

      Explanation:

      Medications and Their Effects on Metabolic Rate

      Medications can have varying effects on the body’s metabolic rate. Some medications are known to decrease metabolic rate, such as sedatives, beta blockers like propranolol, sulphonylureas used to treat diabetes, and certain chemotherapy agents. These medications can slow down the body’s processes and lead to a decrease in energy expenditure.

      On the other hand, there are medications that can increase metabolic rate. Thyroxine, a hormone produced by the thyroid gland, is known to increase metabolic rate. Recombinant human growth hormone, which is used to treat growth hormone deficiency, can also increase metabolic rate. These medications can speed up the body’s processes and lead to an increase in energy expenditure.

      It is important to note that the effects of medications on metabolic rate can vary from person to person and may depend on factors such as dosage and individual health conditions. It is always recommended to consult with a healthcare provider before starting or stopping any medication.

    • This question is part of the following fields:

      • Clinical Sciences
      8.7
      Seconds
  • Question 14 - A 30-year-old woman visits the doctor's office complaining of nausea and vomiting. Upon...

    Incorrect

    • A 30-year-old woman visits the doctor's office complaining of nausea and vomiting. Upon taking a pregnancy test, it is discovered that she is indeed pregnant. Can you identify the location of the chemoreceptor trigger zone?

      Your Answer: Nucleus of tractus solitarius (medulla)

      Correct Answer: Area postrema (medulla)

      Explanation:

      The vomiting process is initiated by the chemoreceptor trigger zone, which receives signals from various sources such as the gastrointestinal tract, hormones, and drugs. This zone is located in the area postrema, which is situated on the floor of the 4th ventricle in the medulla. It is noteworthy that the area postrema is located outside the blood-brain barrier. The nucleus of tractus solitarius, which is also located in the medulla, contains autonomic centres that play a role in the vomiting reflex. This nucleus receives signals from the chemoreceptor trigger zone. The vomiting centres in the brain receive inputs from different areas, including the gastrointestinal tract and the vestibular system of the inner ear.

      Vomiting is the involuntary act of expelling the contents of the stomach and sometimes the intestines. This is caused by a reverse peristalsis and abdominal contraction. The vomiting center is located in the medulla oblongata and is activated by receptors in various parts of the body. These include the labyrinthine receptors in the ear, which can cause motion sickness, the over distention receptors in the duodenum and stomach, the trigger zone in the central nervous system, which can be affected by drugs such as opiates, and the touch receptors in the throat. Overall, vomiting is a reflex action that is triggered by various stimuli and is controlled by the vomiting center in the brainstem.

    • This question is part of the following fields:

      • Neurological System
      45
      Seconds
  • Question 15 - One of the elderly patients at your general practice was recently hospitalized and...

    Correct

    • One of the elderly patients at your general practice was recently hospitalized and diagnosed with myeloma. It was discovered that they have severe chronic kidney disease. The patient comes in for an update on their condition. After reviewing their medications, you realize they are taking ramipril for hypertension, which is contraindicated in renal failure. What is the most accurate description of the effect of ACE inhibitors on glomerular filtration pressure?

      Your Answer: Vasodilation of the efferent arteriole

      Explanation:

      The efferent arteriole experiences vasodilation as a result of ACE inhibitors and ARBs, which inhibit the production of angiotensin II and block its receptors. This leads to a decrease in glomerular filtration pressure and rate, particularly in individuals with renal artery stenosis. On the other hand, the afferent arteriole remains dilated due to the presence of prostaglandins. NSAIDs, which inhibit COX-1 and COX-2, can cause vasoconstriction of the afferent arteriole and a subsequent decrease in glomerular filtration pressure. In healthy individuals, the afferent arteriole remains dilated while the efferent arteriole remains constricted to maintain a balanced glomerular pressure. The patient in the scenario has been diagnosed with myeloma, a disease that arises from the malignant transformation of B-cells and is characterized by bone infiltration, hypercalcaemia, anaemia, and renal impairment.

      Angiotensin-converting enzyme (ACE) inhibitors are commonly used as the first-line treatment for hypertension and heart failure in younger patients. However, they may not be as effective in treating hypertensive Afro-Caribbean patients. ACE inhibitors are also used to treat diabetic nephropathy and prevent ischaemic heart disease. These drugs work by inhibiting the conversion of angiotensin I to angiotensin II and are metabolized in the liver.

      While ACE inhibitors are generally well-tolerated, they can cause side effects such as cough, angioedema, hyperkalaemia, and first-dose hypotension. Patients with certain conditions, such as renovascular disease, aortic stenosis, or hereditary or idiopathic angioedema, should use ACE inhibitors with caution or avoid them altogether. Pregnant and breastfeeding women should also avoid these drugs.

      Patients taking high-dose diuretics may be at increased risk of hypotension when using ACE inhibitors. Therefore, it is important to monitor urea and electrolyte levels before and after starting treatment, as well as any changes in creatinine and potassium levels. Acceptable changes include a 30% increase in serum creatinine from baseline and an increase in potassium up to 5.5 mmol/l. Patients with undiagnosed bilateral renal artery stenosis may experience significant renal impairment when using ACE inhibitors.

      The current NICE guidelines recommend using a flow chart to manage hypertension, with ACE inhibitors as the first-line treatment for patients under 55 years old. However, individual patient factors and comorbidities should be taken into account when deciding on the best treatment plan.

    • This question is part of the following fields:

      • Cardiovascular System
      87.4
      Seconds
  • Question 16 - A patient in his 50s becomes dehydrated, resulting in increased water absorption in...

    Incorrect

    • A patient in his 50s becomes dehydrated, resulting in increased water absorption in the collecting duct. If the concentration of his urine is measured, it would be around 1200mOsm/L. At which point in the nephron would a comparable osmolarity be observed?

      Your Answer: Thick ascending Loop of Henle

      Correct Answer: The tip of the Loop of Henle

      Explanation:

      The Loop of Henle creates the highest osmolarity in the nephron, while the proximal tubule absorbs most of the water. The tip of the papilla has the greatest osmolarity, which is also the maximum osmolarity that urine can attain after water absorption in the collecting ducts. The medulla of the kidney facilitates water reabsorption in the collecting ducts due to the osmotic gradient formed by the Loops of Henle.

      The Loop of Henle and its Role in Renal Physiology

      The Loop of Henle is a crucial component of the renal system, located in the juxtamedullary nephrons and running deep into the medulla. Approximately 60 litres of water containing 9000 mmol sodium enters the descending limb of the loop of Henle in 24 hours. The osmolarity of fluid changes and is greatest at the tip of the papilla. The thin ascending limb is impermeable to water, but highly permeable to sodium and chloride ions. This loss means that at the beginning of the thick ascending limb the fluid is hypo osmotic compared with adjacent interstitial fluid. In the thick ascending limb, the reabsorption of sodium and chloride ions occurs by both facilitated and passive diffusion pathways. The loops of Henle are co-located with vasa recta, which have similar solute compositions to the surrounding extracellular fluid, preventing the diffusion and subsequent removal of this hypertonic fluid. The energy-dependent reabsorption of sodium and chloride in the thick ascending limb helps to maintain this osmotic gradient. Overall, the Loop of Henle plays a crucial role in regulating the concentration of solutes in the renal system.

    • This question is part of the following fields:

      • Renal System
      53.3
      Seconds
  • Question 17 - A 50-year-old man arrives at the emergency department with complaints of increasing fatigue,...

    Correct

    • A 50-year-old man arrives at the emergency department with complaints of increasing fatigue, malaise, and polyuria. He discloses that he had a deceased-donor kidney transplant 3 months ago. Upon conducting a urinalysis, the following results are obtained: positive for protein, negative for blood, glucose, leucocytes, and nitrites. The medical team suspects transplant rejection. Which type of cell is responsible for mediating this complication?

      Your Answer: Cytotoxic T cells

      Explanation:

      Cytotoxic T cells are responsible for both acute and chronic organ rejection. Acute rejection typically occurs within one week to three months after transplantation and is a type IV hypersensitivity reaction, which is cell-mediated. On the other hand, hyperacute rejection, which is a type II hypersensitivity reaction, is mediated by B cells and occurs within 24 hours of transplantation. Granulocytes, infiltrating macrophages, and plasma cells are not the primary drivers of acute organ rejection.

      The adaptive immune response involves several types of cells, including helper T cells, cytotoxic T cells, B cells, and plasma cells. Helper T cells are responsible for the cell-mediated immune response and recognize antigens presented by MHC class II molecules. They express CD4, CD3, TCR, and CD28 and are a major source of IL-2. Cytotoxic T cells also participate in the cell-mediated immune response and recognize antigens presented by MHC class I molecules. They induce apoptosis in virally infected and tumor cells and express CD8 and CD3. Both helper T cells and cytotoxic T cells mediate acute and chronic organ rejection.

      B cells are the primary cells of the humoral immune response and act as antigen-presenting cells. They also mediate hyperacute organ rejection. Plasma cells are differentiated from B cells and produce large amounts of antibody specific to a particular antigen. Overall, these cells work together to mount a targeted and specific immune response to invading pathogens or abnormal cells.

    • This question is part of the following fields:

      • General Principles
      75.1
      Seconds
  • Question 18 - During a hip examination, Sarah, a 65-year-old female, is found to have a...

    Incorrect

    • During a hip examination, Sarah, a 65-year-old female, is found to have a positive trendelenburg's sign. When she stands on only her left leg, her right pelvis drops.

      Which muscles are affected in Sarah?

      Your Answer: Left gluteus maximus and medius

      Correct Answer: Left gluteus medius and gluteus minimus

      Explanation:

      The superior gluteal nerve is responsible for innervating the gluteus minimus and gluteus medius muscles. These muscles are involved in the abduction and medial rotation of the lower limb, as well as preventing pelvic drop of the opposing limb. For instance, when standing on only the right leg, the right gluteus minimus and gluteus medius muscles stabilize the pelvis. However, if the right superior gluteal nerve is damaged, the right gluteus minimus and gluteus medius muscles will not receive innervation, resulting in a lack of stability when standing on the right leg and causing the left pelvis to drop. On the other hand, the inferior gluteal nerve innervates the gluteus maximus muscles, which primarily functions as the main extensor of the thigh and also performs lateral rotation.

      The Trendelenburg Test: Assessing Gluteal Nerve Function

      The Trendelenburg test is a diagnostic tool used to assess the function of the superior gluteal nerve. This nerve is responsible for the contraction of the gluteus medius muscle, which is essential for maintaining balance and stability while standing on one leg.

      When the superior gluteal nerve is injured or damaged, the gluteus medius muscle is weakened, resulting in a compensatory shift of the body towards the unaffected side. This shift is characterized by a gravitational shift, which causes the body to be supported on the unaffected limb.

      To perform the Trendelenburg test, the patient is asked to stand on one leg while the physician observes the position of the pelvis. In a healthy individual, the gluteus medius muscle contracts as soon as the contralateral leg leaves the floor, preventing the pelvis from dipping towards the unsupported side. However, in a person with paralysis of the superior gluteal nerve, the pelvis on the unsupported side descends, indicating that the gluteus medius on the affected side is weak or non-functional. This is known as a positive Trendelenburg test.

      It is important to note that the Trendelenburg test is also used in vascular investigations to determine the presence of saphenofemoral incompetence. In this case, tourniquets are placed around the upper thigh to assess blood flow. However, in the context of assessing gluteal nerve function, the Trendelenburg test is a valuable tool for diagnosing and treating motor deficits and gait abnormalities.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
      43.5
      Seconds
  • Question 19 - A 3-month-old infant is seen by their pediatrician due to their mother's concern...

    Correct

    • A 3-month-old infant is seen by their pediatrician due to their mother's concern about their hand being fixed in an unusual position. The infant had a difficult delivery with shoulder dystocia, but has been healthy since birth and meeting developmental milestones.

      During the exam, the pediatrician observes that the infant's fingers on the left hand are permanently flexed, resembling a claw. There is also muscle wasting in the left forearm. Additionally, the pediatrician notes left-sided miosis, ptosis, and anhidrosis.

      What is the most probable cause of these symptoms in this infant?

      Your Answer: Klumpke paralysis

      Explanation:

      The correct diagnosis for this patient is Klumpke paralysis, which is often caused by shoulder dystocia during birth or traction injuries. The patient presents with a claw-like deformity in their hand, indicating damage to the C8 and T1 branches of the brachial plexus. This condition is also associated with Horner’s syndrome, which the patient is experiencing.

      Bell’s palsy, C8 radiculopathy, and Erb-Duchenne paralysis are all incorrect diagnoses for this patient. Bell’s palsy only affects the facial nerve and would not cause the other symptoms seen in this patient. C8 radiculopathy would not result in the claw-like deformity or T1 dermatome involvement. Erb-Duchenne paralysis affects a different part of the brachial plexus and presents differently from this patient’s symptoms.

      Horner’s syndrome is a condition characterized by several features, including a small pupil (miosis), drooping of the upper eyelid (ptosis), a sunken eye (enophthalmos), and loss of sweating on one side of the face (anhidrosis). The cause of Horner’s syndrome can be determined by examining additional symptoms. For example, congenital Horner’s syndrome may be identified by a difference in iris color (heterochromia), while anhidrosis may be present in central or preganglionic lesions. Pharmacologic tests, such as the use of apraclonidine drops, can also be helpful in confirming the diagnosis and identifying the location of the lesion. Central lesions may be caused by conditions such as stroke or multiple sclerosis, while postganglionic lesions may be due to factors like carotid artery dissection or cluster headaches. It is important to note that the appearance of enophthalmos in Horner’s syndrome is actually due to a narrow palpebral aperture rather than true enophthalmos.

    • This question is part of the following fields:

      • Neurological System
      63.3
      Seconds
  • Question 20 - An 80-year-old woman arrives at the Emergency Department reporting painless loss of vision...

    Correct

    • An 80-year-old woman arrives at the Emergency Department reporting painless loss of vision on the right side that started 30 minutes ago. Based on the history and examination, it is probable that she has experienced an ophthalmic artery stroke. Which branch of the Circle of Willis is likely affected?

      Your Answer: Internal carotid artery

      Explanation:

      The ophthalmic artery originates from the internal carotid artery, which is part of the Circle of Willis, a circular network of arteries that supply the brain. The anterior cerebral arteries, which supply the frontal and parietal lobes, as well as the corpus callosum and cingulate cortex of the brain, also arise from the internal carotid artery. A stroke of the ophthalmic artery or its branch, the central retinal artery, can cause painless loss of vision. The basilar artery, which forms part of the posterior cerebral circulation, is formed from the convergence of the two vertebral arteries and gives rise to many arteries, but not the ophthalmic artery. The posterior cerebral artery, which supplies the occipital lobe, arises from the basilar artery.

      The Circle of Willis is an anastomosis formed by the internal carotid arteries and vertebral arteries on the bottom surface of the brain. It is divided into two halves and is made up of various arteries, including the anterior communicating artery, anterior cerebral artery, internal carotid artery, posterior communicating artery, and posterior cerebral arteries. The circle and its branches supply blood to important areas of the brain, such as the corpus striatum, internal capsule, diencephalon, and midbrain.

      The vertebral arteries enter the cranial cavity through the foramen magnum and lie in the subarachnoid space. They then ascend on the anterior surface of the medulla oblongata and unite to form the basilar artery at the base of the pons. The basilar artery has several branches, including the anterior inferior cerebellar artery, labyrinthine artery, pontine arteries, superior cerebellar artery, and posterior cerebral artery.

      The internal carotid arteries also have several branches, such as the posterior communicating artery, anterior cerebral artery, middle cerebral artery, and anterior choroid artery. These arteries supply blood to different parts of the brain, including the frontal, temporal, and parietal lobes. Overall, the Circle of Willis and its branches play a crucial role in providing oxygen and nutrients to the brain.

    • This question is part of the following fields:

      • Cardiovascular System
      23.6
      Seconds
  • Question 21 - A 16-year-old boy has been diagnosed with aplastic anaemia. He hails from a...

    Correct

    • A 16-year-old boy has been diagnosed with aplastic anaemia. He hails from a family of farmers and used to play hide and seek in the barns where pesticides and other chemicals were stored. He visited his GP complaining of fatigue, dyspnoea, and headaches. Further blood tests revealed a significant leucopenia. Aplastic anaemia is a condition where haematopoietic stem cells that produce immune cell precursors fail. Where in the body are these cells primarily located?

      Your Answer: Bone marrow

      Explanation:

      Aplastic anemia is a condition where there is a shortage of blood cells from all types of progenitor lines. It is most commonly seen in individuals between the ages of 15 to 25 and those over 60.

      The causes of aplastic anemia can be attributed to various factors such as infections (including Epstein-Barr), toxic exposure (such as benzene and radiation), idiopathic, and rarely hereditary.

      Haematopoietic stem cells in the bone marrow generate immune cells. These cells produce two main types of progenitors, myeloid and lymphoid progenitor cells, which give rise to all immune cells.

      Myeloid progenitor cells give rise to cells such as macrophages/monocytes, dendritic cells, neutrophils, eosinophils, basophils, and mast cells. On the other hand, lymphoid progenitor cells give rise to T cells, NK cells, B cells, and dendritic cells.

      Aplastic anaemia is a condition characterized by a decrease in the number of blood cells due to a poorly functioning bone marrow. It is most commonly seen in individuals around the age of 30 and is marked by a reduction in red blood cells, white blood cells, and platelets. While lymphocytes may be relatively spared, the overall effect is a condition known as pancytopenia. In some cases, aplastic anaemia may be the first sign of acute lymphoblastic or myeloid leukaemia. A small number of patients may later develop paroxysmal nocturnal haemoglobinuria or myelodysplasia.

      The causes of aplastic anaemia can be idiopathic, meaning that they are unknown, or they can be linked to congenital conditions such as Fanconi anaemia or dyskeratosis congenita. Certain drugs, such as cytotoxics, chloramphenicol, sulphonamides, phenytoin, and gold, as well as toxins like benzene, can also cause aplastic anaemia. Infections such as parvovirus and hepatitis, as well as exposure to radiation, can also contribute to the development of this condition.

    • This question is part of the following fields:

      • Haematology And Oncology
      248.5
      Seconds
  • Question 22 - A nursing student is being consented for a parathyroidectomy for symptomatic hyperparathyroidism. The...

    Correct

    • A nursing student is being consented for a parathyroidectomy for symptomatic hyperparathyroidism. The parathyroid gland consists of 2 superior and 2 inferior glands. The patient is informed that all four glands will be removed in order to achieve a complete resolution of her symptoms. You explain to her that the superior and inferior glands are derived from different structures.

      From which one of the following embryological structures are the superior parathyroid glands derived from?

      Your Answer: Fourth pharyngeal pouch

      Explanation:

      The superior parathyroid glands are formed from the fourth pharyngeal pouch during embryonic development. The pharyngeal pouches develop between the branchial arches, with the first pouch located between the first and second arches. There are four pairs of pouches, with the fifth pouch being either absent or very small. A helpful mnemonic to remember the derivatives of the four pharyngeal pouches is 1A, 2P, 3 TIP, 4 SUB. This stands for the auditory tube, middle ear cavity, and mastoid antrum for the first pouch; the crypts of the palatine tonsil for the second pouch; the thymus and inferior parathyroid gland for the third pouch; and the superior parathyroid gland and ultimobranchial body for the fourth pouch.

      Anatomy and Development of the Parathyroid Glands

      The parathyroid glands are four small glands located posterior to the thyroid gland within the pretracheal fascia. They develop from the third and fourth pharyngeal pouches, with those derived from the fourth pouch located more superiorly and associated with the thyroid gland, while those from the third pouch lie more inferiorly and may become associated with the thymus.

      The blood supply to the parathyroid glands is derived from the inferior and superior thyroid arteries, with a rich anastomosis between the two vessels. Venous drainage is into the thyroid veins. The parathyroid glands are surrounded by various structures, with the common carotid laterally, the recurrent laryngeal nerve and trachea medially, and the thyroid anteriorly. Understanding the anatomy and development of the parathyroid glands is important for their proper identification and preservation during surgical procedures.

    • This question is part of the following fields:

      • Cardiovascular System
      29.3
      Seconds
  • Question 23 - A 4-month old infant is rushed to the Emergency Department by his parents...

    Incorrect

    • A 4-month old infant is rushed to the Emergency Department by his parents due to difficulty breathing and a blue tint to his face and lips. The parents report that the baby has been experiencing mild cold symptoms for the past 10 days, but his condition has worsened over the last 24 hours. They mention that he has been vomiting after bouts of paroxysmal coughing and had an episode of apnea while sleeping just before they brought him to the hospital. When asked, the mother admits to not receiving all recommended vaccinations during pregnancy. The baby is admitted and started on antibiotics while serology tests are ordered to confirm the diagnosis. What is the most likely pathogen responsible for this infection?

      Your Answer: influenzae virus

      Correct Answer: Bordetella pertussis

      Explanation:

      The patient is exhibiting typical symptoms of whooping cough, which is caused by Bordetella pertussis. After going through the catarrhal stage, the patient has entered the paroxysmal phase, which is characterized by paroxysmal coughing and vomiting. This pattern of symptoms is unique to pertussis and distinguishes it from other bacterial infections. While children are vaccinated against whooping cough, infants rely on their mother’s vaccination during pregnancy, which this mother did not receive. Severe cases of whooping cough can also lead to episodes of cyanosis and apnea, as seen in this patient.

      The patient’s symptoms are not consistent with the common cold, which typically resolves within a week and does not include apnea or cyanosis. Additionally, the use of antibiotics rules out an influenzae virus infection, as viruses do not respond to antibiotics. Streptococcus pyogenes, a common cause of acute pharyngitis in children, presents with fever, sore throat, and swollen lymph nodes, but not coughing.

      Diphtheria is now rare in the UK due to vaccination, but it typically presents with fever, sore throat, difficulty breathing, nasal discharge, and a pseudomembrane on the pharyngeal tonsils.

      Exotoxins vs Endotoxins: Understanding the Differences

      Exotoxins and endotoxins are two types of toxins produced by bacteria. Exotoxins are secreted by bacteria, while endotoxins are only released when the bacterial cell is lysed. Exotoxins are typically produced by Gram-positive bacteria, with some exceptions like Vibrio cholerae and certain strains of E. coli.

      Exotoxins can be classified based on their primary effects, which include pyrogenic toxins, enterotoxins, neurotoxins, tissue invasive toxins, and miscellaneous toxins. Pyrogenic toxins stimulate the release of cytokines, resulting in fever and rash. Enterotoxins act on the gastrointestinal tract, causing either diarrheal or vomiting illness. Neurotoxins act on the nerves or neuromuscular junction, causing paralysis. Tissue invasive toxins cause damage to tissues, while miscellaneous toxins have various effects.

      On the other hand, endotoxins are lipopolysaccharides that are released from Gram-negative bacteria like Neisseria meningitidis. These toxins can cause fever, sepsis, and shock. Unlike exotoxins, endotoxins are not actively secreted by bacteria but are instead released when the bacterial cell is lysed.

      Understanding the differences between exotoxins and endotoxins is important in diagnosing and treating bacterial infections. While exotoxins can be targeted with specific treatments like antitoxins, endotoxins are more difficult to treat and often require supportive care.

    • This question is part of the following fields:

      • General Principles
      103.2
      Seconds
  • Question 24 - A young man comes to the clinic with symptoms suggestive of mania. After...

    Incorrect

    • A young man comes to the clinic with symptoms suggestive of mania. After further inquiry and assessment, he is found to have tachycardia, sweaty palms, and a recent bout of diarrhea. What is the probable diagnosis?

      Your Answer: Generalised anxiety disorder

      Correct Answer: Grave's disease

      Explanation:

      The correct diagnosis for this patient is Grave’s disease, which is characterized by hyperthyroidism. While mania may be a symptom, it is important to note that tachycardia, sweaty hands, and exophthalmos are specific to Grave’s disease.

      Bipolar disorder may also present with manic episodes, but it does not typically include the other symptoms associated with hyperthyroidism.

      Hashimoto’s thyroiditis is another autoimmune thyroid disorder, but it causes hypothyroidism instead of hyperthyroidism. Symptoms of hypothyroidism may include bradycardia and dry skin.

      Graves’ Disease: Common Features and Unique Signs

      Graves’ disease is the most frequent cause of thyrotoxicosis, which is commonly observed in women aged 30-50 years. The condition presents typical features of thyrotoxicosis, such as weight loss, palpitations, and heat intolerance. However, Graves’ disease also displays specific signs that are not present in other causes of thyrotoxicosis. These include eye signs, such as exophthalmos and ophthalmoplegia, as well as pretibial myxoedema and thyroid acropachy. The latter is a triad of digital clubbing, soft tissue swelling of the hands and feet, and periosteal new bone formation.

      Graves’ disease is characterized by the presence of autoantibodies, including TSH receptor stimulating antibodies in 90% of patients and anti-thyroid peroxidase antibodies in 75% of patients. Thyroid scintigraphy reveals a diffuse, homogenous, and increased uptake of radioactive iodine. These features help distinguish Graves’ disease from other causes of thyrotoxicosis and aid in its diagnosis.

    • This question is part of the following fields:

      • Endocrine System
      42
      Seconds
  • Question 25 - A 25-year-old female presents at the renal outpatient clinic with drug-resistant hypertension and...

    Correct

    • A 25-year-old female presents at the renal outpatient clinic with drug-resistant hypertension and longstanding hypokalaemia. After extensive investigation, she is diagnosed with Liddle's syndrome, a rare genetic condition. Along with other medications, amiloride is prescribed. What specific part of the nephron does this medication target?

      Your Answer: Distal convoluted tubule

      Explanation:

      Amiloride is a medication that targets the epithelial sodium transport channels in the distal convoluted tubule (DCT) and collecting duct. It is used to treat Liddle’s syndrome, an autosomal dominant disorder caused by a gain of function mutation that prevents the degradation of these channels, leading to increased activity. This condition is characterized by hypertension, hypokalaemia, and metabolic alkalosis. Amiloride works by selectively blocking these channels, helping to counteract the symptoms of the disease.

      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.

    • This question is part of the following fields:

      • General Principles
      53.5
      Seconds
  • Question 26 - A 57-year-old patient arrives at the emergency department by ambulance following a car...

    Correct

    • A 57-year-old patient arrives at the emergency department by ambulance following a car accident. Upon examination, it is observed that his hip is in flexion, abduction, and external rotation. An X-ray reveals that the right femoral head is larger than the left and is positioned medially to the acetabulum. No fractures or skin lesions are detected. The patient undergoes closed reduction with traction while under sedation. Later, during a physiotherapy evaluation, it is discovered that he is unable to adduct his thigh. What nerve is most likely to have been damaged?

      Your Answer: Obturator nerve

      Explanation:

      If a patient is unable to adduct their thigh after an anterior hip dislocation, it is likely due to damage to the obturator nerve. This nerve supplies the hip adductor muscles and sensation to the medial thigh. In contrast, damage to the femoral nerve would result in an inability to flex the hip or extend the knee, making it an unlikely cause for this specific symptom. Compression of the inferior gluteal nerve can cause piriformis syndrome, while compression of the lateral femoral cutaneous nerve can lead to meralgia paresthetica, but neither of these would affect the patient’s ability to adduct their leg. Damage to the superior gluteal nerve would result in a positive Trendelenburg’s sign.

      Lower limb anatomy is an important topic that often appears in examinations. One aspect of this topic is the nerves that control motor and sensory functions in the lower limb. The femoral nerve controls knee extension and thigh flexion, and provides sensation to the anterior and medial aspect of the thigh and lower leg. It is commonly injured in cases of hip and pelvic fractures, as well as stab or gunshot wounds. The obturator nerve controls thigh adduction and provides sensation to the medial thigh. It can be injured in cases of anterior hip dislocation. The lateral cutaneous nerve of the thigh provides sensory function to the lateral and posterior surfaces of the thigh, and can be compressed near the ASIS, resulting in a condition called meralgia paraesthetica. The tibial nerve controls foot plantarflexion and inversion, and provides sensation to the sole of the foot. It is not commonly injured as it is deep and well protected, but can be affected by popliteal lacerations or posterior knee dislocation. The common peroneal nerve controls foot dorsiflexion and eversion, and can be injured at the neck of the fibula, resulting in foot drop. The superior gluteal nerve controls hip abduction and can be injured in cases of misplaced intramuscular injection, hip surgery, pelvic fracture, or posterior hip dislocation. Injury to this nerve can result in a positive Trendelenburg sign. The inferior gluteal nerve controls hip extension and lateral rotation, and is generally injured in association with the sciatic nerve. Injury to this nerve can result in difficulty rising from a seated position, as well as difficulty jumping or climbing stairs.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
      149.1
      Seconds
  • Question 27 - What is the lymphatic drainage of the ovaries? ...

    Correct

    • What is the lymphatic drainage of the ovaries?

      Your Answer: Para-aortic nodes

      Explanation:

      The para-aortic nodes receive lymphatic drainage from the ovary through the gonadal vessels.

      Lymphatic Drainage of Female Reproductive Organs

      The lymphatic drainage of the female reproductive organs is a complex system that involves multiple nodal stations. The ovaries drain to the para-aortic lymphatics via the gonadal vessels. The uterine fundus has a lymphatic drainage that runs with the ovarian vessels and may thus drain to the para-aortic nodes. Some drainage may also pass along the round ligament to the inguinal nodes. The body of the uterus drains through lymphatics contained within the broad ligament to the iliac lymph nodes. The cervix drains into three potential nodal stations; laterally through the broad ligament to the external iliac nodes, along the lymphatics of the uterosacral fold to the presacral nodes and posterolaterally along lymphatics lying alongside the uterine vessels to the internal iliac nodes. Understanding the lymphatic drainage of the female reproductive organs is important for the diagnosis and treatment of gynecological cancers.

    • This question is part of the following fields:

      • Haematology And Oncology
      26
      Seconds
  • Question 28 - A 68-year-old man is brought into the emergency department by his wife after...

    Incorrect

    • A 68-year-old man is brought into the emergency department by his wife after she found him complaining of a headache, drowsiness, and difficulty walking. He is currently on warfarin therapy for deep vein thrombosis. The man states that he has had several falls in the past month or so, and has recently become more confused. A magnetic resonance imaging (MRI) scan is ordered for the man.

      Where would you suspect blood to collect in this case?

      Your Answer: Between the pia mater and the arachnoid mater

      Correct Answer: Between the arachnoid mater and the dura mater

      Explanation:

      The arachnoid mater is the middle layer of the meninges. The described condition is a subdural haemorrhage or haematoma, which is a collection of blood between the arachnoid mater and the dura mater. It is often caused by chronic mild trauma and is common in the elderly and those on anticoagulant therapy. MRI scans show a concave pool of blood. There is no potential space between the pia mater and the arachnoid mater for blood to fill.

      The Three Layers of Meninges

      The meninges are a group of membranes that cover the brain and spinal cord, providing support to the central nervous system and the blood vessels that supply it. These membranes can be divided into three distinct layers: the dura mater, arachnoid mater, and pia mater.

      The outermost layer, the dura mater, is a thick fibrous double layer that is fused with the inner layer of the periosteum of the skull. It has four areas of infolding and is pierced by small areas of the underlying arachnoid to form structures called arachnoid granulations. The arachnoid mater forms a meshwork layer over the surface of the brain and spinal cord, containing both cerebrospinal fluid and vessels supplying the nervous system. The final layer, the pia mater, is a thin layer attached directly to the surface of the brain and spinal cord.

      The meninges play a crucial role in protecting the brain and spinal cord from injury and disease. However, they can also be the site of serious medical conditions such as subdural and subarachnoid haemorrhages. Understanding the structure and function of the meninges is essential for diagnosing and treating these conditions.

    • This question is part of the following fields:

      • Neurological System
      60
      Seconds
  • Question 29 - Which enzyme is likely to be dysfunctional in patients with chronic granulomatous disease,...

    Incorrect

    • Which enzyme is likely to be dysfunctional in patients with chronic granulomatous disease, resulting in their inability to efficiently eliminate bacteria after ingestion by macrophages?

      Your Answer: C5 convertase

      Correct Answer: NADPH oxidase

      Explanation:

      Granulocyte Bacterial Killing Mechanisms

      Granulocytes have a unique way of killing bacteria. Although it is a rare condition, it exemplifies the bacterial killing mechanisms of granulocytes. Once a bacterium is ingested, granulocytes fuse the phagosome with lysosomes that contain proteolytic enzymes. Additionally, they produce oxygen radicals (O2-) that can react with nitric oxide (forming ONOO-), both of which are harmful to bacteria. This process is known as the respiratory burst and utilises the enzyme NADPH oxidase. Patients who have a loss of function of NADPH oxidase are unable to effectively kill bacteria, which leads to the formation of granulomas, sealing off the infection. These patients are immunosuppressed.

      In contrast, a C5-convertase is a complex of proteins involved in the complement cascade. Carbonic anhydrase catalyses the formation of carbonic acid from water and CO2. Lactate dehydrogenase converts pyruvate into lactic acid. TDT is an enzyme that is used to insert mutations into somatic DNA during the formation of the B cell and T cell receptor. Each of these processes has a unique function in the body, but the granulocyte bacterial killing mechanism is particularly fascinating due to its ability to effectively combat bacterial infections.

    • This question is part of the following fields:

      • Clinical Sciences
      103
      Seconds
  • Question 30 - A 50-year-old male is referred by his GP for an endoscopy due to...

    Correct

    • A 50-year-old male is referred by his GP for an endoscopy due to recurrent indigestion. During the procedure, a small duodenal ulcer is discovered and Helicobacter pylori is found to be present. What is the recommended treatment for this patient?

      Your Answer: Omeprazole, metronidazole and clarithromycin

      Explanation:

      Helicobacter pylori and Peptic Ulceration

      The bacterium Helicobacter pylori, which is classified as a gram-negative curved rod, has been linked to the development of peptic ulceration by inhibiting the healing process. In fact, up to 90% of patients with duodenal ulceration and 70% of cases of peptic ulceration may be infected with Helicobacter. To treat this infection, therapy should focus on acid suppression and eradication of the bacterium. Triple therapy, which involves a proton pump inhibitor like omeprazole along with two antibiotics (amoxicillin/clarithromycin plus metronidazole), has been found to be the most effective treatment. This therapy should be administered for one week, with proton pump therapy continuing thereafter.

    • This question is part of the following fields:

      • Pharmacology
      22
      Seconds
  • Question 31 - A mother brings her 6-year-old daughter into hospital worried that she is slower...

    Correct

    • A mother brings her 6-year-old daughter into hospital worried that she is slower than the other girls when standing up. Upon further inquiry, the mother discloses that her daughter walks in an unusual manner and that her grandmother passed away when she was very young. What is the probable cause of the young girl's condition?

      Your Answer: Mutation in the gene coding for dystrophin

      Explanation:

      Duchenne muscular dystrophy (DMD) is characterised by a waddling gait and Gower’s sign, and follows an X-linked recessive pattern of inheritance. Cystic fibrosis is caused by improper chloride ion channel formation, myasthenia gravis by an autoimmune process against acetylcholine receptors, phenylketonuria by a lack of phenylalanine breakdown, and sickle cell anaemia by a mutation in the gene coding for haemoglobin.

      Dystrophinopathies are a group of genetic disorders that are inherited in an X-linked recessive manner. These disorders are caused by mutations in the dystrophin gene located on the X chromosome at position Xp21. Dystrophin is a protein that is part of a larger membrane-associated complex in muscle cells. It connects the muscle membrane to actin, which is a component of the muscle cytoskeleton.

      Duchenne muscular dystrophy is a severe form of dystrophinopathy that is caused by a frameshift mutation in the dystrophin gene. This mutation results in the loss of one or both binding sites, leading to progressive proximal muscle weakness that typically begins around the age of 5 years. Children with Duchenne muscular dystrophy may also exhibit calf pseudohypertrophy and Gower’s sign, which is when they use their arms to stand up from a squatted position. Approximately 30% of patients with Duchenne muscular dystrophy also have intellectual impairment.

      In contrast, Becker muscular dystrophy is a milder form of dystrophinopathy that typically develops after the age of 10 years. It is caused by a non-frameshift insertion in the dystrophin gene, which preserves both binding sites. Intellectual impairment is much less common in individuals with Becker muscular dystrophy.

    • This question is part of the following fields:

      • Neurological System
      51
      Seconds
  • Question 32 - Where does spironolactone act in the kidney? ...

    Correct

    • Where does spironolactone act in the kidney?

      Your Answer: 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.

    • This question is part of the following fields:

      • General Principles
      10.7
      Seconds
  • Question 33 - A carpal tunnel release results in median nerve damage. Which muscles will be...

    Correct

    • A carpal tunnel release results in median nerve damage. Which muscles will be impacted by this in the patient?

      Your Answer: Abductor pollicis brevis

      Explanation:

      Only the abductor pollicis brevis is innervated by the median nerve, while the other muscles are innervated by different nerves. It is important to be careful not to confuse the terms adductor and abductor when discussing muscle innervation.

      Abductor Pollicis Brevis: Anatomy and Function

      The abductor pollicis brevis is a muscle located in the palm of the hand. It originates from the flexor retinaculum, scaphoid, and trapezium bones and inserts into the radial side of the proximal phalanx of the thumb via a short tendon. The muscle is innervated by the recurrent branch of the median nerve in the palm.

      The main function of the abductor pollicis brevis is to abduct the thumb at the carpometacarpal and metacarpophalangeal joints. This causes the thumb to move anteriorly at right angles to the plane of the palm and to rotate medially, which is useful for activities such as typing. When the thumb is fully abducted, there is an angulation of around 30 degrees between the proximal phalanx and the metacarpal.

      Abduction of the thumb involves medial rotation of the metacarpal, and the abductor pollicis brevis is used along with the opponens pollicis in the initial stages of thumb opposition. Overall, the abductor pollicis brevis plays an important role in the movement and function of the thumb.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
      57.8
      Seconds
  • Question 34 - A 26-year-old woman has arrived at the emergency department following a blow to...

    Incorrect

    • A 26-year-old woman has arrived at the emergency department following a blow to her left leg while playing soccer.

      During the examination, her reflexes and tone appear normal, but she is experiencing difficulty in inverting her foot and has numbness on the plantar surface of her foot.

      Which nerve is the most probable to have been damaged?

      Your Answer: Tibial nerve

      Correct Answer: Superficial peroneal nerve

      Explanation:

      When the superficial peroneal nerve is injured, it can lead to a loss of foot eversion and a loss of sensation over the dorsum of the foot. This nerve controls the fibularis longus and brevis muscles, which are responsible for evertion of the foot. It also provides sensory input to the skin of the anterolateral leg and dorsum of the foot, except for the area between the first and second toes.

      Anatomy of the Superficial Peroneal Nerve

      The superficial peroneal nerve is responsible for supplying the lateral compartment of the leg, specifically the peroneus longus and peroneus brevis muscles which aid in eversion and plantar flexion. It also provides sensation over the dorsum of the foot, excluding the first web space which is innervated by the deep peroneal nerve.

      The nerve passes between the peroneus longus and peroneus brevis muscles along the proximal one-third of the fibula. Approximately 10-12 cm above the tip of the lateral malleolus, the nerve pierces the fascia. It then bifurcates into intermediate and medial dorsal cutaneous nerves about 6-7 cm distal to the fibula.

      Understanding the anatomy of the superficial peroneal nerve is important in diagnosing and treating conditions that affect the lateral compartment of the leg and dorsum of the foot. Injuries or compression of the nerve can result in weakness or numbness in the affected areas.

    • This question is part of the following fields:

      • Neurological System
      30
      Seconds
  • Question 35 - A 4-year-old girl is brought to the emergency department by her father after...

    Correct

    • A 4-year-old girl is brought to the emergency department by her father after the child has been having a fever and has been very irritable since last night. The child has a temperature of 39.5ºC, and the emergency doctor notices that the child has a red tongue and cracked lips. On examination cervical lymph nodes are enlarged. After noticing that the child's palms and soles are erythematous, the emergency doctor calls the pediatrician on call, and they make a decision to begin treatment. What is the severe complication that can occur if this patient is not treated appropriately and on time?

      Your Answer: Coronary artery aneurysm

      Explanation:

      Kawasaki disease can lead to coronary artery aneurysms, which should be screened for with an echocardiogram. Prompt treatment with intravenous immunoglobulin and aspirin is necessary to prevent this complication. Other potential complications, such as septic shock or febrile seizures, are not as severe as coronary artery aneurysms in this case. Anaphylactic shock is not a possibility based on the information provided.

      Understanding Kawasaki Disease

      Kawasaki disease is a rare type of vasculitis that primarily affects children. It is important to identify this disease early on as it can lead to serious complications such as coronary artery aneurysms. The disease is characterized by a high-grade fever that lasts for more than five days, which is resistant to antipyretics. Other features include conjunctival injection, bright red, cracked lips, strawberry tongue, cervical lymphadenopathy, and red palms and soles that later peel.

      Diagnosis of Kawasaki disease is based on clinical presentation as there is no specific diagnostic test available. Management of the disease involves high-dose aspirin, which is one of the few indications for aspirin use in children. Intravenous immunoglobulin is also used as a treatment option. Echocardiogram is the initial screening test for coronary artery aneurysms instead of angiography.

      Complications of Kawasaki disease include coronary artery aneurysm, which can be life-threatening. Early recognition and treatment of Kawasaki disease can prevent serious complications and improve outcomes for affected children.

    • This question is part of the following fields:

      • Cardiovascular System
      35
      Seconds
  • Question 36 - A 40-year-old man from Kenya visits your clinic complaining of feeling constantly fatigued....

    Incorrect

    • A 40-year-old man from Kenya visits your clinic complaining of feeling constantly fatigued. He reports having a persistent cough for the past 6 weeks, which has been keeping him up at night. He also mentions coughing up blood on occasion. Additionally, he has been experiencing night sweats, causing his sheets to become drenched. His wife notes that he appears to be at his worst during the evenings and often has a temperature around that time. Upon examination, he appears tired and has a mild fever of 37.9ºC. A sputum sample is taken, which fails to take up a Gram stain but reveals acid-fast bacilli with the Ziehl-Neelsen test. A chest X-ray shows hilar lymphadenopathy and a cavitating lesion in the right apex. If a lung biopsy were to be taken of the surrounding tissues, what histological finding would be observed?

      Your Answer: Reed-sternberg cells

      Correct Answer: Epitheliod histiocytes

      Explanation:

      The presence of epithelioid histiocytes in a granuloma is a common histological finding in patients with Tuberculosis. This is consistent with the patient’s history and geographical origin. Epithelioid histiocytes are elongated macrophages that resemble epithelial cells. In cases where there is necrosis, it is referred to as a Caseating granuloma due to its resemblance to casein in cheese.

      Keratin pearl is a histological finding in squamous cell carcinoma of the lung, which may also present as a cavitating lesion. However, it would not grow acid-fast bacilli, unlike TB.

      Psammoma bodies are typically found in papillary thyroid carcinoma.

      Owls-eye nucleus is a characteristic finding in a CMV infection.

      Reed-Sternberg cells are commonly found in Hodgkin’s lymphoma, which typically presents with B symptoms such as fever, night sweats, and weight loss. However, based on the other findings, this diagnosis is unlikely.

      Types of Tuberculosis

      Tuberculosis (TB) is a disease caused by Mycobacterium tuberculosis that primarily affects the lungs. There are two types of TB: primary and secondary. Primary TB occurs when a non-immune host is exposed to the bacteria and develops a small lung lesion called a Ghon focus. This focus is made up of macrophages containing tubercles and is accompanied by hilar lymph nodes, forming a Ghon complex. In immunocompetent individuals, the lesion usually heals through fibrosis. However, those who are immunocompromised may develop disseminated disease, also known as miliary tuberculosis.

      Secondary TB, also called post-primary TB, occurs when the initial infection becomes reactivated in an immunocompromised host. Reactivation typically occurs in the apex of the lungs and can spread locally or to other parts of the body. Factors that can cause immunocompromise include immunosuppressive drugs, HIV, and malnutrition. While the lungs are still the most common site for secondary TB, it can also affect other areas such as the central nervous system, vertebral bodies, cervical lymph nodes, renal system, and gastrointestinal tract. Tuberculous meningitis is the most serious complication of extra-pulmonary TB. Understanding the differences between primary and secondary TB is crucial in diagnosing and treating the disease.

    • This question is part of the following fields:

      • General Principles
      47.3
      Seconds
  • Question 37 - A 25-year-old woman comes to the clinic with a thyroid cancer. She has...

    Incorrect

    • A 25-year-old woman comes to the clinic with a thyroid cancer. She has no significant family history and is in good health. During the examination, a nodule is found in the left lobe of her thyroid, which appears to be a small, distinct mass separate from the gland. What is the most probable cause of this finding?

      Your Answer: Follicular carcinoma

      Correct Answer: Papillary carcinoma

      Explanation:

      The most frequent subtype of thyroid cancer is papillary carcinoma, which can lead to lymph node metastasis. This occurrence is uncommon in follicular tumors. Anaplastic carcinoma is rare in this age group and would result in more localized symptoms.

      Thyroid cancer rarely causes hyperthyroidism or hypothyroidism as it does not usually secrete thyroid hormones. The most common type of thyroid cancer is papillary carcinoma, which is often found in young females and has an excellent prognosis. Follicular carcinoma is less common, while medullary carcinoma is a cancer of the parafollicular cells that secrete calcitonin and is associated with multiple endocrine neoplasia type 2. Anaplastic carcinoma is rare and not responsive to treatment, causing pressure symptoms. Lymphoma is also rare and associated with Hashimoto’s thyroiditis.

      Management of papillary and follicular cancer involves a total thyroidectomy followed by radioiodine to kill residual cells. Yearly thyroglobulin levels are monitored to detect early recurrent disease. Papillary carcinoma usually contains a mixture of papillary and colloidal filled follicles, while follicular adenoma presents as a solitary thyroid nodule and malignancy can only be excluded on formal histological assessment. Follicular carcinoma may appear macroscopically encapsulated, but microscopically capsular invasion is seen. Medullary carcinoma is associated with raised serum calcitonin levels and familial genetic disease in up to 20% of cases. Anaplastic carcinoma is most common in elderly females and is treated by resection where possible, with palliation achieved through isthmusectomy and radiotherapy. Chemotherapy is ineffective.

    • This question is part of the following fields:

      • Endocrine System
      168
      Seconds
  • Question 38 - A 54-year-old male presents to the hospital with a chief complaint of central...

    Correct

    • A 54-year-old male presents to the hospital with a chief complaint of central chest pain, accompanied by nausea and sweating that has been ongoing for two hours. After eight hours of the onset of the pain, the following result is obtained:
      Troponin T 30.8 ug/L (<10)
      What is the probable diagnosis?

      Your Answer: Myocardial infarction

      Explanation:

      Elevated Troponin T as a Marker of Cardiac Injury

      This patient’s troponin T concentration is significantly elevated, indicating cardiac injury. Troponin T is a component of the cardiac myocyte and is normally undetectable. Elevated levels of troponin T are highly specific to cardiac injury and are more reliable than creatinine kinase, which is less specific. Troponin T levels increase in acute coronary syndromes, myocarditis, and myocardial infarction.

      In this patient’s case, the elevated troponin T suggests a myocardial infarction (MI) due to the symptoms presented. Troponin T can be detected within a few hours of an MI and peaks at 14 hours after the onset of pain. It may peak again several days later and remain elevated for up to 10 days. Therefore, it is a good test for acute MI but not as reliable for recurrent MI in the first week. CK-MB may be useful in this case as it starts to rise 10-24 hours after an MI and disappears after three to four days.

      Other conditions that may present with similar symptoms include aortic dissection, which causes tearing chest pain that often radiates to the back with hypotension. ECG changes are not always present. Myocarditis causes chest pain that improves with steroids or NSAIDs and a rise in troponin levels, with similar ECG changes to a STEMI. There may also be reciprocal lead ST depression and PR depression. Pulmonary embolism presents with shortness of breath, pleuritic chest pain, hypoxia, and hemoptysis. Pericardial effusion presents with similar symptoms to pericarditis, with Kussmaul’s sign typically present.

    • This question is part of the following fields:

      • Cardiovascular System
      23.9
      Seconds
  • Question 39 - Which process occurs mainly in the smooth endoplasmic reticulum? ...

    Incorrect

    • Which process occurs mainly in the smooth endoplasmic reticulum?

      Your Answer: Synthesis of exported proteins

      Correct Answer: Steroid synthesis

      Explanation:

      The Functions of Different Organelles in a Cell

      The endoplasmic reticulum (ER) is a network of membranes that is present in eukaryotic cells. There are two types of ER: rough and smooth. The rough ER has a rough appearance due to the presence of ribosomes on its cytosolic side, which makes it involved in protein production, modification, and transport. On the other hand, the smooth ER is involved in cholesterol and steroid handling, as well as calcium storage in some cells. It is particularly prominent in cells that produce large amounts of steroid hormones, such as those of the adrenal cortex.

      Lysosomes are organelles that are responsible for breaking down and recycling cellular waste. They generally bud off from the Golgi apparatus, which is another organelle in the cell. The Golgi apparatus is involved in modifying, sorting, and packaging proteins and lipids for transport to their final destinations.

      The nucleus is the organelle that contains the genetic material of the cell. It is responsible for the transcription and translation of DNA and RNA, which are the processes that lead to the production of proteins. The nucleus is surrounded by a double membrane called the nuclear envelope, which has pores that allow for the transport of molecules in and out of the nucleus.

      In summary, different organelles in a cell have specific functions that are essential for the proper functioning of the cell. The ER is involved in protein production and modification, the Golgi apparatus is responsible for sorting and packaging proteins and lipids, lysosomes break down and recycle cellular waste, and the nucleus is responsible for the transcription and translation of DNA and RNA.

    • This question is part of the following fields:

      • Clinical Sciences
      48
      Seconds
  • Question 40 - A 58-year-old man, previously diagnosed with small cell lung cancer, visits his GP...

    Incorrect

    • A 58-year-old man, previously diagnosed with small cell lung cancer, visits his GP complaining of a recent onset headache, nausea, and vomiting that have been worsening over the past week. He reports feeling dizzy when the headache starts and an unusual increase in appetite, resulting in weight gain. Despite his history of little appetite due to his lung cancer, he has been insatiable lately. Which part of the hypothalamus is likely affected by the metastasis of his lung cancer, causing these symptoms?

      Your Answer: Lateral nucleus

      Correct Answer: Ventromedial nucleus

      Explanation:

      The ventromedial nucleus of the hypothalamus is responsible for regulating satiety, and therefore, damage to this area can result in hyperphagia.

      The posterior nucleus plays a role in stimulating the sympathetic nervous system and body heat, and lesions in this area can lead to autonomic dysfunction and poikilothermia.

      The lateral nucleus is responsible for stimulating appetite, and damage to this area can cause a decrease in appetite and anorexia.

      The paraventricular nucleus produces oxytocin and ADH, and lesions in this area can result in diabetes insipidus.

      The dorsomedial nucleus is responsible for stimulating aggressive behavior and can lead to savage behavior if damaged.

      The hypothalamus is a part of the brain that plays a crucial role in maintaining the body’s internal balance, or homeostasis. It is located in the diencephalon and is responsible for regulating various bodily functions. The hypothalamus is composed of several nuclei, each with its own specific function. The anterior nucleus, for example, is involved in cooling the body by stimulating the parasympathetic nervous system. The lateral nucleus, on the other hand, is responsible for stimulating appetite, while lesions in this area can lead to anorexia. The posterior nucleus is involved in heating the body and stimulating the sympathetic nervous system, and damage to this area can result in poikilothermia. Other nuclei include the septal nucleus, which regulates sexual desire, the suprachiasmatic nucleus, which regulates circadian rhythm, and the ventromedial nucleus, which is responsible for satiety. Lesions in the paraventricular nucleus can lead to diabetes insipidus, while lesions in the dorsomedial nucleus can result in savage behavior.

    • This question is part of the following fields:

      • Neurological System
      89.7
      Seconds

SESSION STATS - PERFORMANCE PER SPECIALTY

Respiratory System (0/1) 0%
Musculoskeletal System And Skin (2/5) 40%
General Principles (5/7) 71%
Clinical Sciences (1/4) 25%
Renal System (3/4) 75%
Psychiatry (0/1) 0%
Cardiovascular System (6/6) 100%
Neurological System (3/7) 43%
Haematology And Oncology (2/2) 100%
Endocrine System (0/2) 0%
Pharmacology (1/1) 100%
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