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Question 1
Correct
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A 42-year-old woman visits her GP complaining of chest pain. She has a history of hypertension and is currently taking metformin for diabetes. The GP observes that her BMI is 45. What is a possible complication of the metabolic syndrome in this case?
Your Answer: Ischemic stroke
Explanation:Metabolic syndrome is a group of risk factors for cardiovascular disease that are caused by insulin resistance and central obesity.
Obesity is associated with higher rates of illness and death, as well as decreased productivity and functioning, increased healthcare expenses, and social and economic discrimination.
The consequences of obesity include strokes, type 2 diabetes, heart disease, certain cancers (such as breast, colon, and endometrial), polycystic ovarian syndrome, obstructive sleep apnea, fatty liver, gallstones, and mental health issues.
The Physiology of Obesity: Leptin and Ghrelin
Leptin is a hormone produced by adipose tissue that plays a crucial role in regulating body weight. It acts on the hypothalamus, specifically on the satiety centers, to decrease appetite and induce feelings of fullness. In cases of obesity, where there is an excess of adipose tissue, leptin levels are high. Leptin also stimulates the release of melanocyte-stimulating hormone (MSH) and corticotrophin-releasing hormone (CRH), which further contribute to the regulation of appetite. On the other hand, low levels of leptin stimulate the release of neuropeptide Y (NPY), which increases appetite.
Ghrelin, on the other hand, is a hormone that stimulates hunger. It is mainly produced by the P/D1 cells lining the fundus of the stomach and epsilon cells of the pancreas. Ghrelin levels increase before meals, signaling the body to prepare for food intake, and decrease after meals, indicating that the body has received enough nutrients.
In summary, the balance between leptin and ghrelin plays a crucial role in regulating appetite and body weight. In cases of obesity, there is an imbalance in this system, with high levels of leptin and potentially disrupted ghrelin signaling, leading to increased appetite and weight gain.
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This question is part of the following fields:
- Endocrine System
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Question 2
Correct
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An 80-year-old patient, Gwyneth, is being examined by her physician for recurring dizziness upon standing up, which is interfering with her daily activities. Gwyneth is in good health and does not take any regular medications. The physician diagnoses Gwyneth with orthostatic hypotension and prescribes fludrocortisone as a treatment.
What is the most probable side effect that Gwyneth may encounter?Your Answer: Fluid retention
Explanation:Corticosteroids are a class of medications commonly prescribed for various clinical uses, such as treating allergies, inflammatory conditions, auto-immunity, and endogenous steroid replacement.
There are different types of corticosteroids, each with varying levels of glucocorticoid and mineralocorticoid activity. Glucocorticoids mimic cortisol, which is involved in carbohydrate metabolism and the stress response, while mineralocorticoids mimic aldosterone, which regulates sodium and water retention in response to low blood pressure.
The clinical uses and side effects of corticosteroids depend on their level of glucocorticoid and mineralocorticoid activity. Fludrocortisone, for example, has minimal glucocorticoid activity and high mineralocorticoid activity.
Therefore, fluid retention is the most associated side effect with mineralocorticoid activity, while depression, hyperglycemia, osteoporosis, and peptic ulceration are side effects associated with glucocorticoid activity.
Corticosteroids are commonly prescribed medications that can be taken orally or intravenously, or applied topically. They mimic the effects of natural steroids in the body and can be used to replace or supplement them. However, the use of corticosteroids is limited by their numerous side effects, which are more common with prolonged and systemic use. These side effects can affect various systems in the body, including the endocrine, musculoskeletal, gastrointestinal, ophthalmic, and psychiatric systems. Some of the most common side effects include impaired glucose regulation, weight gain, osteoporosis, and increased susceptibility to infections. Patients on long-term corticosteroids should have their doses adjusted during intercurrent illness, and the medication should not be abruptly withdrawn to avoid an Addisonian crisis. Gradual withdrawal is recommended for patients who have received high doses or prolonged treatment.
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This question is part of the following fields:
- Endocrine System
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Question 3
Incorrect
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As a third year medical student working in a GP surgery, you come across a worried 54-year-old male patient who is experiencing chest discomfort. He has recently begun taking a new tablet for his high blood pressure and suspects it may be the cause of his symptoms. During your examination, you notice bilateral non-tender glandular swellings around the areolae. There are no signs of lymphadenopathy in the axillary region, and testicular examination is normal. Which medication is most likely responsible for this clinical presentation?
Your Answer: Bendroflumethiazide
Correct Answer: Spironolactone
Explanation:Spironolactone-Induced Gynaecomastia
Spironolactone is a type of diuretic that helps to increase urine production by blocking aldosterone receptors in the kidneys. However, it also has anti-androgenic properties that can lead to the development of gynaecomastia, a condition where men develop breast tissue. This is because spironolactone inhibits the production of testosterone and increases the level of free oestrogen in the blood, causing the proliferation of glandular tissue in the mammary glands.
While gynaecomastia is not commonly associated with other medications, they all have their own side effects. Aspirin, for example, can cause gastrointestinal ulceration by inhibiting COX enzymes and prostaglandin synthesis. Thiazide diuretics work by blocking the sodium chloride co-transporter in the distal convoluted tubule, which can lead to a decrease in blood volume. Loop diuretics, on the other hand, can cause severe hyponatraemia but do not affect testosterone production. Statins, which are used to lower cholesterol levels, can cause rhabdomyolysis, a serious condition where muscle tissue breaks down and releases harmful substances into the bloodstream.
In summary, while spironolactone can be an effective diuretic, it is important to be aware of its potential side effects, including gynaecomastia. Patients should always consult with their healthcare provider before starting any new medication and report any unusual symptoms or side effects.
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This question is part of the following fields:
- Endocrine System
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Question 4
Incorrect
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Which one of the following statements is true of glucagon?
Your Answer: Produced in response to hyperglycaemia
Correct Answer: Produced in response to an increase of amino acids
Explanation:Glucagon is a polypeptide protein that is synthesized by the alpha cells of the pancreatic islets of Langerhans. It is released in response to low blood sugar levels and the presence of amino acids. Glucagon is responsible for elevating the levels of glucose and ketones in the bloodstream.
Glucagon: The Hormonal Antagonist to Insulin
Glucagon is a hormone that is released from the alpha cells of the Islets of Langerhans in the pancreas. It has the opposite metabolic effects to insulin, resulting in increased plasma glucose levels. Glucagon functions by promoting glycogenolysis, gluconeogenesis, and lipolysis. It is regulated by various factors such as hypoglycemia, stresses like infections, burns, surgery, increased catecholamines, and sympathetic nervous system stimulation, as well as increased plasma amino acids. On the other hand, glucagon secretion decreases with hyperglycemia, insulin, somatostatin, and increased free fatty acids and keto acids.
Glucagon is used to rapidly reverse the effects of hypoglycemia in diabetics. It is an essential hormone that plays a crucial role in maintaining glucose homeostasis in the body. Its antagonistic relationship with insulin helps to regulate blood glucose levels and prevent hyperglycemia. Understanding the regulation and function of glucagon is crucial in the management of diabetes and other metabolic disorders.
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This question is part of the following fields:
- Endocrine System
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Question 5
Incorrect
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A 47-year-old female has been diagnosed with Grave's disease, experiencing weight loss, heat intolerance, and a tremor that is affecting her job as a waitress. Despite being prescribed carbimazole, she is unhappy with the results after 3 days. What other medication options are available for symptom management?
Your Answer:
Correct Answer: Beta blockers
Explanation:To alleviate symptoms, beta blockers like propranolol can be used to block the sympathetic effects on the heart. Guanethidine can also be administered to reduce catecholamine release. Statins and calcium channel blockers are not effective in treating the patient’s symptoms. Although benzodiazepines have anxiolytic and sedative properties, they may not be the most suitable option in this case.
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.
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This question is part of the following fields:
- Endocrine System
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Question 6
Incorrect
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Which of the following most accurately explains how glucocorticoids work?
Your Answer:
Correct Answer: Binding of intracellular receptors that migrate to the nucleus to then affect gene transcription
Explanation:The effects of glucocorticoids are mediated by intracellular receptors that bind to them and are subsequently transported to the nucleus, where they modulate gene transcription.
Corticosteroids are commonly prescribed medications that can be taken orally or intravenously, or applied topically. They mimic the effects of natural steroids in the body and can be used to replace or supplement them. However, the use of corticosteroids is limited by their numerous side effects, which are more common with prolonged and systemic use. These side effects can affect various systems in the body, including the endocrine, musculoskeletal, gastrointestinal, ophthalmic, and psychiatric systems. Some of the most common side effects include impaired glucose regulation, weight gain, osteoporosis, and increased susceptibility to infections. Patients on long-term corticosteroids should have their doses adjusted during intercurrent illness, and the medication should not be abruptly withdrawn to avoid an Addisonian crisis. Gradual withdrawal is recommended for patients who have received high doses or prolonged treatment.
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This question is part of the following fields:
- Endocrine System
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Question 7
Incorrect
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A 55-year-old man with a smoking history of over 30 years presented to the emergency department with acute confusion and disorientation. He was unable to recognize his family members and relatives. He had been experiencing unexplained weight loss, loss of appetite, and occasional episodes of haemoptysis for the past few months. Urgent blood tests were performed, revealing abnormal levels of electrolytes and renal function.
Based on the likely diagnosis, what is the mechanism of action of the hormone that is being secreted excessively in this case?Your Answer:
Correct Answer: Insertion of aquaporin-2 channels
Explanation:Antidiuretic hormone (ADH) plays a crucial role in promoting water reabsorption by inserting aquaporin-2 channels in principal cells. In small-cell lung cancer patients, decreased serum sodium levels are commonly caused by the paraneoplastic syndrome of inadequate ADH secretion (SIADH) or ADH released during the initial lysis of tumour cells after chemotherapy. It is important to note that arteriolar vasodilation, promoting water excretion, decreased urine osmolarity, and increased portal blood flow are not functions of ADH.
Understanding Antidiuretic Hormone (ADH)
Antidiuretic hormone (ADH) is a hormone that is produced in the supraoptic nuclei of the hypothalamus and released by the posterior pituitary gland. Its primary function is to conserve body water by promoting water reabsorption in the collecting ducts of the kidneys through the insertion of aquaporin-2 channels.
ADH secretion is regulated by various factors. An increase in extracellular fluid osmolality, a decrease in volume or pressure, and the presence of angiotensin II can all increase ADH secretion. Conversely, a decrease in extracellular fluid osmolality, an increase in volume, a decrease in temperature, or the absence of ADH can decrease its secretion.
Diabetes insipidus (DI) is a condition that occurs when there is either a deficiency of ADH (cranial DI) or an insensitivity to ADH (nephrogenic DI). Cranial DI can be treated with desmopressin, which is an analog of ADH.
Overall, understanding the role of ADH in regulating water balance in the body is crucial for maintaining proper hydration and preventing conditions like DI.
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This question is part of the following fields:
- Endocrine System
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Question 8
Incorrect
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A 14-year-old boy presents to the emergency department with complaints of severe abdominal pain, nausea, and vomiting for the past 6 hours. The patient appears drowsy and has dry mucous membranes. His vital signs include a heart rate of 94 beats per minute, respiratory rate of 19 breaths per minute, and blood pressure of 89/62 mmHg. There is a fruity smell to his breath, and a bedside glucose finger prick reveals a glucose level of 263 mg/dL. The doctor orders an insulin infusion while waiting for laboratory results. Which insulin preparation is most appropriate for this patient's management?
Your Answer:
Correct Answer: Short-acting (regular) insulin
Explanation:The onset of action and peak of NPH and regular insulin are a result of the combination of both human recombinant insulin preparations in the mixture.
Understanding Insulin Therapy
Insulin therapy has been a game-changer in the management of diabetes mellitus since its development in the 1920s. It remains the only available treatment for type 1 diabetes mellitus (T1DM) and is widely used in type 2 diabetes mellitus (T2DM) when oral hypoglycemic agents fail to provide adequate control. However, understanding the different types of insulin can be overwhelming, and it is crucial to have a basic grasp to avoid potential harm to patients.
Insulin can be classified by manufacturing process, duration of action, and type of insulin analogues. Patients often require a combination of preparations to ensure stable glycemic control throughout the day. Rapid-acting insulin analogues act faster and have a shorter duration of action than soluble insulin and may be used as the bolus dose in ‘basal-bolus’ regimes. Short-acting insulins, such as Actrapid and Humulin S, may also be used as the bolus dose in ‘basal-bolus’ regimes. Intermediate-acting insulins, like isophane insulin, are often used in a premixed formulation with long-acting insulins, such as insulin determir and insulin glargine, given once or twice daily. Premixed preparations combine intermediate-acting insulin with either a rapid-acting insulin analogue or soluble insulin.
The vast majority of patients administer insulin subcutaneously, and it is essential to rotate injection sites to prevent lipodystrophy. Insulin pumps are available, which delivers a continuous basal infusion and a patient-activated bolus dose at meal times. Intravenous insulin is used for patients who are acutely unwell, such as those with diabetic ketoacidosis. Inhaled insulin is available but not widely used, and oral insulin analogues are in development but have considerable technical hurdles to clear. Overall, understanding insulin therapy is crucial for healthcare professionals to provide safe and effective care for patients with diabetes mellitus.
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This question is part of the following fields:
- Endocrine System
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Question 9
Incorrect
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A 34-year-old male presents with tingling in his thumb, index, and middle finger, along with complaints of excessive fatigue and snoring. Upon examination, he displays a prominent brow ridge and significant facial changes over time. Following blood tests and an MRI scan, the patient is prescribed octreotide. What is the mechanism of action of this medication?
Your Answer:
Correct Answer: Somatostatin analogue
Explanation:Acromegaly is a condition that results from excessive growth hormone production. The release of growth hormone is directly inhibited by somatostatin, which is why somatostatin analogues are used to treat acromegaly.
To answer the question, one must first recognize the symptoms of acromegaly, such as carpal tunnel syndrome, sleep apnea, and changes in facial features over time. The second part of the question involves identifying octreotide as a somatostatin analogue commonly used to treat acromegaly.
While dopamine agonists were previously used to treat acromegaly, they are no longer preferred due to the availability of more effective treatments. Dopamine antagonists have never been used to treat acromegaly. Pegvisomant is an example of a growth hormone antagonist, but antagonists for insulin growth factor-1 release have not yet been developed.
Acromegaly is a condition that can be managed through various treatment options. The first-line treatment for the majority of patients is trans-sphenoidal surgery. However, if the pituitary tumour is inoperable or surgery is unsuccessful, medication may be indicated. One such medication is a somatostatin analogue, which directly inhibits the release of growth hormone. Octreotide is an example of this medication and is effective in 50-70% of patients. Another medication is pegvisomant, which is a GH receptor antagonist that prevents dimerization of the GH receptor. It is administered once daily subcutaneously and is very effective, decreasing IGF-1 levels in 90% of patients to normal. However, it does not reduce tumour volume, so surgery is still needed if there is a mass effect. Dopamine agonists, such as bromocriptine, were the first effective medical treatment for acromegaly but are now superseded by somatostatin analogues and are only effective in a minority of patients. External irradiation may be used for older patients or following failed surgical/medical treatment.
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This question is part of the following fields:
- Endocrine System
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Question 10
Incorrect
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Sarah is a 15-year-old female who presented to the clinic with concerns about her development. She has not grown as expected and remains shorter than most of the girls in her class. She also notes that she has not started her period yet, which is affecting her confidence.
On examination, she is 150cm tall and has no breast development. Pubic hair is sparse and axillary hair is absent. The uterus and ovaries are not palpable. A cleft palate is noted on examination of the mouth. When cranial nerve I was examined, she was unable to detect the smell of the odours sampled.
Blood tests show low levels of estrogen, follicular stimulating hormone (FSH) and luteinizing hormone (LH). Liver function tests were normal. Blood glucose reading was 5.6mmol/L. Iron studies were unremarkable.
What is the likely cause for her symptoms?Your Answer:
Correct Answer: Kallmann syndrome
Explanation:The patient’s symptoms of delayed puberty and underdeveloped secondary sexual characteristics, along with a cleft palate and anosmia, suggest Kallmann syndrome. This condition is characterized by hypogonadotropic hypogonadism, as evidenced by low-normal levels of LH and FSH, as well as low testosterone levels. Kallmann syndrome is an X-linked inherited disorder caused by the failure of gonadotrophin-releasing hormone-producing neurons to migrate properly during fetal development.
While Klinefelter syndrome can also cause delayed puberty and small testes, it is associated with hypergonadotropic hypogonadism, which is characterized by elevated levels of FSH and LH but low testosterone levels. Anosmia is not typically a symptom of Klinefelter syndrome.
Hemochromatosis, a condition in which iron accumulates in the body, can also cause hypogonadotropic hypogonadism by affecting the hypothalamus. However, this is unlikely in this case as the patient’s iron studies were normal and anosmia is not a common symptom of hemochromatosis.
Kallmann’s syndrome is a condition that can cause delayed puberty due to hypogonadotropic hypogonadism. It is often inherited as an X-linked recessive trait and is believed to be caused by a failure of GnRH-secreting neurons to migrate to the hypothalamus. One of the key indicators of Kallmann’s syndrome is anosmia, or a lack of smell, in boys with delayed puberty. Other features may include hypogonadism, cryptorchidism, low sex hormone levels, and normal or above-average height. Some patients may also have cleft lip/palate and visual/hearing defects.
Management of Kallmann’s syndrome typically involves testosterone supplementation. Gonadotrophin supplementation may also be used to stimulate sperm production if fertility is desired later in life. It is important for individuals with Kallmann’s syndrome to receive appropriate medical care and monitoring to manage their symptoms and ensure optimal health outcomes.
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This question is part of the following fields:
- Endocrine System
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Question 11
Incorrect
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A 29-year-old male attends a pre-operative assessment clinic for thyroidectomy due to failed treatment with carbimazole and radio-iodine for Grave's disease. What is the potential complication that he is at a high risk of developing during this procedure?
Your Answer:
Correct Answer: Recurrent laryngeal nerve palsy
Explanation:The risk of complications during thyroidectomy is relatively low, but there are still potential risks to be aware of. One of the most common complications is damage to the recurrent laryngeal nerve, which can result in vocal cord paralysis and hoarseness. However, the vagal nerve and phrenic nerve are rarely damaged during the procedure as they are not in close proximity to the operating site. Trauma to the esophagus is also uncommon. If the parathyroid glands are inadvertently removed during the procedure, it can result in hypoparathyroidism rather than hyperparathyroidism.
Thyroid disorders are commonly encountered in clinical practice, with hypothyroidism and thyrotoxicosis being the most prevalent. Women are ten times more likely to develop these conditions than men. The thyroid gland is a bi-lobed structure located in the anterior neck and is part of a hypothalamus-pituitary-end organ system that regulates the production of thyroxine and triiodothyronine hormones. These hormones help regulate energy sources, protein synthesis, and the body’s sensitivity to other hormones. Hypothyroidism can be primary or secondary, while thyrotoxicosis is mostly primary. Autoimmunity is the leading cause of thyroid problems in the developed world.
Thyroid disorders can present in various ways, with symptoms often being the opposite depending on whether the thyroid gland is under or overactive. For example, hypothyroidism may result in weight gain, while thyrotoxicosis leads to weight loss. Thyroid function tests are the primary investigation for diagnosing thyroid disorders. These tests primarily look at serum TSH and T4 levels, with T3 being measured in specific cases. TSH levels are more sensitive than T4 levels for monitoring patients with existing thyroid problems.
Treatment for thyroid disorders depends on the cause. Patients with hypothyroidism are given levothyroxine to replace the underlying deficiency. Patients with thyrotoxicosis may be treated with propranolol to control symptoms such as tremors, carbimazole to reduce thyroid hormone production, or radioiodine treatment.
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This question is part of the following fields:
- Endocrine System
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Question 12
Incorrect
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A 16-year-old patient presents to his GP with concerns about his physical development. The patient reports feeling self-conscious about his body shape and experiencing bullying at school. On examination, the patient is noted to have gynaecomastia and microorchidism. The patient is referred to a paediatrician, who subsequently refers the patient to the genetics team. As part of their assessment, the genetics team orders a karyotype.
What karyotype results would be expected for this patient, given the likely diagnosis?Your Answer:
Correct Answer: Klinefelter syndrome (47,XXY)
Explanation:Understanding Klinefelter’s Syndrome
Klinefelter’s syndrome is a genetic condition that is characterized by an extra X chromosome, resulting in a karyotype of 47, XXY. Individuals with this syndrome often have a taller than average stature, but lack secondary sexual characteristics. They may also have small, firm testes and be infertile. Gynaecomastia, or the development of breast tissue, is also common in individuals with Klinefelter’s syndrome, and there is an increased risk of breast cancer. Despite elevated levels of gonadotrophins, testosterone levels are typically low.
Diagnosis of Klinefelter’s syndrome is made through karyotyping, which involves analyzing an individual’s chromosomes. It is important for individuals with this condition to receive appropriate medical care and support, as well as genetic counseling for family planning.
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This question is part of the following fields:
- Endocrine System
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Question 13
Incorrect
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A 65-year-old man with a history of poorly-controlled type 2 diabetes presents to the emergency department with altered mental status. His daughter reports that he has been complaining of increased thirst and urination over the past few days and has been skipping his insulin injections. On examination, he is dehydrated with a GCS of 3. His vital signs are recorded, and he is intubated and given ventilatory support. An arterial blood gas shows mild metabolic acidosis and his capillary blood glucose is undetectable. What is the next most appropriate step in his treatment?
Your Answer:
Correct Answer: 0.9% sodium chloride
Explanation:In the ABCDE approach, the patient should be promptly given sodium chloride to restore their intravascular volume and maintain circulatory function. However, insulin is not recommended as an initial treatment for HHS. This is because glucose in the intravascular space helps maintain circulating volume, which is crucial for dehydrated patients. Administering insulin before fluid resuscitation can cause a reduction in intravascular volume and worsen hypotension. It may also worsen pre-existing hypokalaemia by driving potassium into the intracellular space. Potassium chloride should be administered only after fluid resuscitation and guided by potassium levels obtained from an arterial blood gas. Thiamine supplementation is not indicated at the moment as urgent resuscitation should be the priority.
Hyperosmolar hyperglycaemic state (HHS) is a serious medical emergency that can be challenging to manage and has a high mortality rate of up to 20%. It is typically seen in elderly patients with type 2 diabetes mellitus (T2DM) and is caused by hyperglycaemia leading to osmotic diuresis, severe dehydration, and electrolyte imbalances. HHS develops gradually over several days, resulting in extreme dehydration and metabolic disturbances. Symptoms include polyuria, polydipsia, lethargy, nausea, vomiting, altered consciousness, and focal neurological deficits. Diagnosis is based on hypovolaemia, marked hyperglycaemia, significantly raised serum osmolarity, and no significant hyperketonaemia or acidosis.
Management of HHS involves fluid replacement with IV 0.9% sodium chloride solution at a rate of 0.5-1 L/hour, depending on clinical assessment. Potassium levels should be monitored and added to fluids as needed. Insulin should not be given unless blood glucose stops falling while giving IV fluids. Patients are at risk of thrombosis due to hyperviscosity, so venous thromboembolism prophylaxis is recommended. Complications of HHS include vascular complications such as myocardial infarction and stroke.
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This question is part of the following fields:
- Endocrine System
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Question 14
Incorrect
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A 33-year-old woman with a history of coeliac disease presents to the emergency department with palpitations, diaphoresis, and tremors. Upon examination, her vital signs reveal a heart rate of 110 bpm and respiratory rate of 24 per min. She displays hand tremors, bulging eyeballs, and diffuse swelling in her neck. Her blood tests show:
TSH 0.1 mU/l
Free T4 32.5 pmol/l
Free T3 12.5 pmol/l
What is the most probable underlying pathophysiology in this patient?Your Answer:
Correct Answer: Antibodies to TSH receptors
Explanation:Graves’ disease is the most probable cause of thyrotoxicosis in a middle-aged woman, particularly if she exhibits exophthalmos. This autoimmune disorder is characterised by the presence of antibodies to the thyroid stimulating hormone (TSH) receptors.
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.
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This question is part of the following fields:
- Endocrine System
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Question 15
Incorrect
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You have been requested to evaluate a patient in your general practice, who has come in after discovering a new lump in her neck. The patient is in her mid-40s, has no significant medical history, and does not take any regular medications.
Upon examination, you observe a small mass in the front of the neck that moves upwards when the patient swallows. There is no associated lymphadenopathy. You refer the patient for an ultrasound and biopsy, which reveals the presence of 'Orphan Annie eyes with psammoma bodies.'
Based on this finding, what is the most probable diagnosis?Your Answer:
Correct Answer: Papillary thyroid cancer
Explanation:The patient has a painless lump in the thyroid gland that moves on swallowing, indicating thyroid pathology. The biopsy result of Orphan Annie eyes with psammoma bodies is a characteristic finding in papillary thyroid cancer, which is a slow-growing malignancy with less likelihood of lymphadenopathy. Graves’ disease is an incorrect diagnosis as it would not present with this appearance on biopsy and would likely exhibit signs of thyrotoxicosis. A multinodular goitre also does not have this appearance and may cause a thyrotoxic state. Anaplastic carcinoma is a more aggressive thyroid malignancy that readily invades nearby tissues and has a different histological appearance with spindle cells and giant cells.
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.
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This question is part of the following fields:
- Endocrine System
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Question 16
Incorrect
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A 42-year-old woman has been admitted to the renal ward with acute kidney injury. Her blood test shows that her potassium levels are above normal limits. While renal failure is a known cause of hyperkalaemia, the patient mentions having an endocrine disorder in the past but cannot recall its name. This information is crucial as certain endocrine disorders can also cause potassium disturbances. Which of the following endocrine disorders is commonly associated with hyperkalaemia?
Your Answer:
Correct Answer: Addison's disease
Explanation:The correct answer is Addison’s disease, which is a condition of primary adrenal insufficiency. One of the hormones that is deficient in this disease is aldosterone, which plays a crucial role in maintaining the balance of potassium in the body. Aldosterone activates Na+/K+ ATPase pumps on the cell wall, causing the movement of potassium into the cell and increasing renal potassium secretion. Therefore, a lack of aldosterone leads to hyperkalaemia.
Phaeochromocytomas are tumours that produce catecholamines and typically arise in the adrenal medulla. They are associated with hypertension and hyperglycaemia, but not disturbances in potassium balance.
Hyperthyroidism is a condition of excess thyroid hormone and does not affect potassium balance.
Conn’s syndrome, on the other hand, is a type of primary hyperaldosteronism where there is excess aldosterone production. Aldosterone activates the Na+/K+ pump on the cell wall, causing the movement of potassium into the cell, which can lead to hypokalaemia.
Addison’s disease is the most common cause of primary hypoadrenalism in the UK, with autoimmune destruction of the adrenal glands being the main culprit, accounting for 80% of cases. This results in reduced production of cortisol and aldosterone. Symptoms of Addison’s disease include lethargy, weakness, anorexia, nausea and vomiting, weight loss, and salt-craving. Hyperpigmentation, especially in palmar creases, vitiligo, loss of pubic hair in women, hypotension, hypoglycemia, and hyponatremia and hyperkalemia may also be observed. In severe cases, a crisis may occur, leading to collapse, shock, and pyrexia.
Other primary causes of hypoadrenalism include tuberculosis, metastases (such as bronchial carcinoma), meningococcal septicaemia (Waterhouse-Friderichsen syndrome), HIV, and antiphospholipid syndrome. Secondary causes include pituitary disorders, such as tumours, irradiation, and infiltration. Exogenous glucocorticoid therapy can also lead to hypoadrenalism.
It is important to note that primary Addison’s disease is associated with hyperpigmentation, while secondary adrenal insufficiency is not.
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This question is part of the following fields:
- Endocrine System
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Question 17
Incorrect
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A 65-year-old man presents with abdominal tenderness, steatorrhoea, and jaundice. Upon investigation, a somatostatinoma of the pancreas is discovered. What is the probable cell type from which this neoplasm originated?
Your Answer:
Correct Answer: Delta-cells
Explanation:Somatostatin is secreted by the delta cells located in the pancreas. These cells are also present in the stomach, duodenum, and jejunum. In the pancreas, somatostatin plays a role in inhibiting the release of exocrine enzymes, glucagon, and insulin. In rare cases of large somatostatinomas, patients may experience mild diabetes mellitus.
The answer choices of alpha-cells, beta-cells, and S-cells are incorrect as they secrete glucagon, insulin, and secretin, respectively.
Somatostatin: The Inhibitor Hormone
Somatostatin, also known as growth hormone inhibiting hormone (GHIH), is a hormone produced by delta cells found in the pancreas, pylorus, and duodenum. Its main function is to inhibit the secretion of growth hormone, insulin, and glucagon. It also decreases acid and pepsin secretion, as well as pancreatic enzyme secretion. Additionally, somatostatin inhibits the trophic effects of gastrin and stimulates gastric mucous production.
Somatostatin analogs are commonly used in the management of acromegaly, a condition characterized by excessive growth hormone secretion. These analogs work by inhibiting growth hormone secretion, thereby reducing the symptoms associated with acromegaly.
The secretion of somatostatin is regulated by various factors. Its secretion increases in response to fat, bile salts, and glucose in the intestinal lumen, as well as glucagon. On the other hand, insulin decreases the secretion of somatostatin.
In summary, somatostatin plays a crucial role in regulating the secretion of various hormones and enzymes in the body. Its inhibitory effects on growth hormone, insulin, and glucagon make it an important hormone in the management of certain medical conditions.
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This question is part of the following fields:
- Endocrine System
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Question 18
Incorrect
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A 57-year-old woman presents for her routine check-up. She has recently been prescribed insulin for management of her type 2 diabetes. While discussing her medical history, she reports experiencing numbness in her entire right foot. Upon examination, an ulcer is observed on the webbing between her fourth and fifth toes.
What would be the most appropriate next course of action to investigate this woman's condition?Your Answer:
Correct Answer: Full neurovascular examination of the lower limbs
Explanation:The two main factors that contribute to diabetic foot disease are loss of sensation and peripheral arterial disease. When reviewing a diabetic patient who presents with a complication, it is crucial to recognize that those with a loss of protective sensation are at a high risk of developing diabetic foot disease. Therefore, any ulcers must be promptly managed to prevent severe infection.
Out of the given options, the most appropriate next step in managing this patient is to conduct a full neurovascular examination of their lower limbs. While checking the HbA1C levels is important, it is not the immediate concern for this patient. Similarly, examining foot sensation using a 10g monofilament is a crucial step, but it is only a part of a comprehensive neurovascular examination. Measuring C-peptide is not relevant to the current situation.
Diabetic foot disease is a significant complication of diabetes mellitus that requires regular screening. In 2015, NICE published guidelines on diabetic foot disease. The disease is caused by two main factors: neuropathy, which results in a loss of protective sensation, and peripheral arterial disease, which can cause macro and microvascular ischaemia. Symptoms of diabetic foot disease include loss of sensation, absent foot pulses, reduced ankle-brachial pressure index (ABPI), intermittent claudication, calluses, ulceration, Charcot’s arthropathy, cellulitis, osteomyelitis, and gangrene.
All patients with diabetes should be screened for diabetic foot disease at least once a year. Screening for ischaemia involves palpating for both the dorsalis pedis pulse and posterial tibial artery pulse, while screening for neuropathy involves using a 10 g monofilament on various parts of the sole of the foot. NICE recommends that patients be risk-stratified into low, moderate, and high-risk categories based on factors such as deformity, previous ulceration or amputation, renal replacement therapy, and the presence of calluses or neuropathy. Patients who are moderate or high-risk should be regularly followed up by their local diabetic foot centre.
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This question is part of the following fields:
- Endocrine System
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Question 19
Incorrect
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A 42-year-old man with schizophrenia undergoes his yearly physical examination. He is currently taking risperidone as part of his medication regimen.
What is the most common issue that can be linked to the use of risperidone in this patient?Your Answer:
Correct Answer: Galactorrhoea
Explanation:Risperidone, an atypical antipsychotic, has the potential to increase prolactin levels. This is because it inhibits dopamine, which reduces dopamine-mediated inhibition of prolactin. Although elevated prolactin may not cause any symptoms, it can have adverse effects if persistently elevated. One of the major roles of prolactin is to stimulate milk production in the mammary glands. Therefore, any cause of raised prolactin can result in milk production, which is known as galactorrhoea. This can occur in both males and females due to raised prolactin levels. Galactorrhoea is the most likely side effect caused by risperidone.
Raised prolactin levels can also lead to reduced libido and infertility in both sexes. However, it is unlikely to result in increased libido. Prolactin can interfere with other hormones, such as oestrogen and progesterone, which can cause irregular periods, but it does not specifically cause painful periods. Elevated levels of prolactin would not result in seizures. Risperidone is more likely to be associated with weight gain rather than weight loss, as it acts on the histamine receptor.
Understanding Prolactin and Its Functions
Prolactin is a hormone that is produced by the anterior pituitary gland. Its primary function is to stimulate breast development and milk production in females. During pregnancy, prolactin levels increase to support the growth and development of the mammary glands. It also plays a role in reducing the pulsatility of gonadotropin-releasing hormone (GnRH) at the hypothalamic level, which can block the action of luteinizing hormone (LH) on the ovaries or testes.
The secretion of prolactin is regulated by dopamine, which constantly inhibits its release. However, certain factors can increase or decrease prolactin secretion. For example, prolactin levels increase during pregnancy, in response to estrogen, and during breastfeeding. Additionally, stress, sleep, and certain drugs like metoclopramide and antipsychotics can also increase prolactin secretion. On the other hand, dopamine and dopaminergic agonists can decrease prolactin secretion.
Overall, understanding the functions and regulation of prolactin is important for reproductive health and lactation.
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This question is part of the following fields:
- Endocrine System
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Question 20
Incorrect
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A 59-year-old man with a known history of type-2 diabetes comes for a check-up. He is currently on metformin only for his diabetes and reports compliance with the prescribed regimen.
His HbA1c is 63 mmol/mol (target = 53mmol/mol) and the patient and clinician agree to initiate a sulfonylurea along with his metformin.
What is the primary mode of action of the new treatment?Your Answer:
Correct Answer: Increases stimulation of insulin secretion by pancreatic B-cells and decreases hepatic clearance of insulin
Explanation:Sulfonylureas are a type of oral hypoglycemic agent that stimulate insulin secretion by pancreatic B-cells and reduce the clearance of insulin by the liver. They are known as insulin secretagogues.
Sulfonylureas are a type of medication used to treat type 2 diabetes mellitus. They work by increasing the amount of insulin produced by the pancreas, but only if the beta cells in the pancreas are functioning properly. Sulfonylureas bind to a specific channel on the cell membrane of pancreatic beta cells, known as the ATP-dependent K+ channel (KATP).
While sulfonylureas can be effective in managing diabetes, they can also cause some adverse effects. The most common side effect is hypoglycemia, which is more likely to occur with long-acting preparations like chlorpropamide. Another common side effect is weight gain. However, there are also rarer side effects that can occur, such as hyponatremia (low sodium levels) due to inappropriate ADH secretion, bone marrow suppression, hepatotoxicity (liver damage), and peripheral neuropathy.
It is important to note that sulfonylureas should not be used during pregnancy or while breastfeeding.
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This question is part of the following fields:
- Endocrine System
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Question 21
Incorrect
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A 32-year-old woman comes to the clinic complaining of fatigue and weight loss that has been going on for 6 weeks. She reports feeling dizzy when she stands up and has noticed a tan all over her body, despite it being early spring in the UK.
Upon conducting a blood test, it is found that she has hyponatraemia and hyperkalaemia, with normal full blood count results. A lying-standing blood pressure reading shows a postural drop of 36 mmHg.
What is the most likely cause of this woman's presentation in the UK, given her symptoms and test results?Your Answer:
Correct Answer: Autoimmune adrenal insufficiency
Explanation:The most likely cause of this patient’s symptoms is autoimmune adrenalitis, which is responsible for the majority of cases of hypoadrenalism. In this condition, auto-antibodies attack the adrenal gland, leading to a decrease or complete loss of cortisol and aldosterone production. This results in low blood pressure, electrolyte imbalances, and a significant drop in blood pressure upon standing. The body compensates for the low cortisol levels by producing more adrenocorticotropic hormone (ACTH), which can cause the skin to take on a bronze hue.
While iodine deficiency is a common cause of hypothyroidism worldwide, it is not consistent with this patient’s presentation. A mutation in the HFE gene can lead to haemochromatosis, which can cause reduced libido and skin darkening, but it does not match the electrolyte abnormalities described. Pituitary tumors and tuberculosis can also cause hypoadrenalism, but they are less common in the UK compared to autoimmune causes.
Addison’s disease is the most common cause of primary hypoadrenalism in the UK, with autoimmune destruction of the adrenal glands being the main culprit, accounting for 80% of cases. This results in reduced production of cortisol and aldosterone. Symptoms of Addison’s disease include lethargy, weakness, anorexia, nausea and vomiting, weight loss, and salt-craving. Hyperpigmentation, especially in palmar creases, vitiligo, loss of pubic hair in women, hypotension, hypoglycemia, and hyponatremia and hyperkalemia may also be observed. In severe cases, a crisis may occur, leading to collapse, shock, and pyrexia.
Other primary causes of hypoadrenalism include tuberculosis, metastases (such as bronchial carcinoma), meningococcal septicaemia (Waterhouse-Friderichsen syndrome), HIV, and antiphospholipid syndrome. Secondary causes include pituitary disorders, such as tumours, irradiation, and infiltration. Exogenous glucocorticoid therapy can also lead to hypoadrenalism.
It is important to note that primary Addison’s disease is associated with hyperpigmentation, while secondary adrenal insufficiency is not.
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This question is part of the following fields:
- Endocrine System
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Question 22
Incorrect
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As a medical student in community care, while shadowing a health visitor, I observed her measuring the height and weight of children to monitor their growth. What factors drive growth during the developmental stage of 4 to 10 years old?
Your Answer:
Correct Answer: Growth and thyroid hormones
Explanation:Understanding Growth and Factors Affecting It
Growth is a significant difference between children and adults, and it occurs in three stages: infancy, childhood, and puberty. Several factors affect fetal growth, including environmental, placental, hormonal, and genetic factors. Maternal nutrition and uterine capacity are the most crucial environmental factors that affect fetal growth.
In infancy, nutrition and insulin are the primary drivers of growth. High fetal insulin levels result from poorly controlled diabetes in the mother, leading to hypoglycemia and macrosomia in the baby. Growth hormone is not a significant factor in infancy, as babies have low amounts of receptors. Hypopituitarism and thyroid have no effect on growth in infancy.
In childhood, growth is driven by growth hormone and thyroxine, while in puberty, growth is driven by growth hormone and sex steroids. Genetic factors are the most important determinant of final adult height.
It is essential to monitor growth in children regularly. Infants aged 0-1 years should have at least five weight recordings, while children aged 1-2 years should have at least three weight recordings. Children older than two years should have annual weight recordings. Children below the 2nd centile for height should be reviewed by their GP, while those below the 0.4th centile for height should be reviewed by a paediatrician.
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This question is part of the following fields:
- Endocrine System
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Question 23
Incorrect
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A 50-year-old man has a laparotomy and repair of incisional hernia. Which hormone is most unlikely to be released in higher amounts after the surgery?
Your Answer:
Correct Answer: Insulin
Explanation:Reduced secretion of insulin and thyroxine is common after surgery, which can make it challenging to manage diabetes in people with insulin resistance due to the additional release of glucocorticoids.
Surgery triggers a stress response that causes hormonal and metabolic changes in the body. This response is characterized by substrate mobilization, muscle protein loss, sodium and water retention, suppression of anabolic hormone secretion, activation of the sympathetic nervous system, and immunological and haematological changes. The hypothalamic-pituitary axis and the sympathetic nervous systems are activated, and the normal feedback mechanisms of control of hormone secretion fail. The stress response is associated with increased growth hormone, cortisol, renin, adrenocorticotrophic hormone (ACTH), aldosterone, prolactin, antidiuretic hormone, and glucagon, while insulin, testosterone, oestrogen, thyroid stimulating hormone, luteinizing hormone, and follicle stimulating hormone are decreased or remain unchanged. The metabolic effects of cortisol are enhanced, including skeletal muscle protein breakdown, stimulation of lipolysis, anti-insulin effect, mineralocorticoid effects, and anti-inflammatory effects. The stress response also affects carbohydrate, protein, lipid, salt and water metabolism, and cytokine release. Modifying the response can be achieved through opioids, spinal anaesthesia, nutrition, growth hormone, anabolic steroids, and normothermia.
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This question is part of the following fields:
- Endocrine System
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Question 24
Incorrect
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A 55-year-old woman comes to her doctor complaining of fatigue, difficulty passing stool, and muscle weakness. Her lab results show:
Free T4 6 pmol/l (9-18 pmol/l)
TSH 7.2 mu/l (0.5-5.5 mu/l)
Based on the probable diagnosis, which of the following tests is most likely to be positive in this patient?Your Answer:
Correct Answer: Anti-thyroid peroxidase (anti-TPO) antibodies
Explanation:Rheumatoid factor is not the most suitable answer for a patient with hypothyroidism, despite its presence in various rheumatological conditions and healthy individuals.
Understanding Thyroid Autoantibodies
Thyroid autoantibodies are antibodies that attack the thyroid gland, causing various thyroid disorders. There are three main types of anti-thyroid autoantibodies: anti-thyroid peroxidase (anti-TPO) antibodies, TSH receptor antibodies, and thyroglobulin antibodies. Anti-TPO antibodies are present in 90% of Hashimoto’s thyroiditis cases and 75% of Graves’ disease cases. TSH receptor antibodies are found in 90-100% of Graves’ disease cases. Thyroglobulin antibodies are present in 70% of Hashimoto’s thyroiditis cases, 30% of Graves’ disease cases, and a small proportion of thyroid cancer cases.
Understanding the different types of thyroid autoantibodies is important in diagnosing and treating thyroid disorders. Hashimoto’s thyroiditis and Graves’ disease are the most common autoimmune thyroid disorders, and the presence of specific autoantibodies can help differentiate between the two. Additionally, monitoring the levels of these antibodies can help track the progression of the disease and the effectiveness of treatment. Overall, understanding thyroid autoantibodies is crucial in managing thyroid health.
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This question is part of the following fields:
- Endocrine System
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Question 25
Incorrect
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A 25-year-old woman presents for her first-trimester review at the antenatal clinic. She reports feeling well with no specific concerns. Due to complications in her previous pregnancy, she undergoes several screening blood tests, including thyroid function testing. The results reveal a TSH level of 4.2 mIU/L (normal range: 0.4-4.0), thyroxine (T4) level of 220 nmol/L (normal range: 64-155), and free thyroxine (fT4) level of 15 pmol/L (normal range: 12.0-21.9). Despite having no symptoms of thyrotoxicosis and a normal physical examination, what thyroid-associated protein primarily causes these findings to occur?
Your Answer:
Correct Answer: Thyroid binding globulin
Explanation:During pregnancy, thyroid function can be affected, leading to a range of conditions. However, in the case of a patient with a nodular goitre, antithyroid antibodies are not a likely cause. Thyroglobulin levels may increase slightly in the final trimester, but this is not the primary issue. Similarly, while TSH levels may be raised in pregnancy, this is a secondary effect caused by an increase in TBG.
During pregnancy, there is an increase in the levels of thyroxine-binding globulin (TBG), which causes an increase in the levels of total thyroxine. However, this does not affect the free thyroxine level. If left untreated, thyrotoxicosis can increase the risk of fetal loss, maternal heart failure, and premature labor. Graves’ disease is the most common cause of thyrotoxicosis during pregnancy, but transient gestational hyperthyroidism can also occur due to the activation of the TSH receptor by HCG. Propylthiouracil has traditionally been the antithyroid drug of choice, but it is associated with an increased risk of severe hepatic injury. Therefore, NICE Clinical Knowledge Summaries recommend using propylthiouracil in the first trimester and switching to carbimazole in the second trimester. Maternal free thyroxine levels should be kept in the upper third of the normal reference range to avoid fetal hypothyroidism. Thyrotropin receptor stimulating antibodies should be checked at 30-36 weeks gestation to determine the risk of neonatal thyroid problems. Block-and-replace regimes should not be used in pregnancy, and radioiodine therapy is contraindicated.
On the other hand, thyroxine is safe during pregnancy, and serum thyroid-stimulating hormone should be measured in each trimester and 6-8 weeks postpartum. Women require an increased dose of thyroxine during pregnancy, up to 50% as early as 4-6 weeks of pregnancy. Breastfeeding is safe while on thyroxine. It is important to manage thyroid problems during pregnancy to ensure the health of both the mother and the baby.
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This question is part of the following fields:
- Endocrine System
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Question 26
Incorrect
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Mr. Smith is a 54-year-old man who visits your GP clinic for his annual review of his type 2 diabetes. He informs you that he has been managing it through diet for a few years, but lately, he has gained some weight. His latest HbA1C reading is 9.8% (normal range 3.7-5.0%). You suggest continuous dietary advice and prescribe metformin to regulate his blood glucose levels. Which of the following statements about metformin is accurate?
Your Answer:
Correct Answer: It decreases hepatic gluconeogenesis
Explanation:While some diabetic treatments such as insulin and sulfonylureas can lead to weight gain, metformin is not associated with this side effect. Metformin functions by enhancing insulin sensitivity and reducing hepatic gluconeogenesis, without directly impacting insulin secretion from pancreatic beta cells, thus it does not cause significant hypoglycemia. Ghrelin, a hormone that controls appetite, is not influenced by any diabetic medications.
Understanding Diabetes Mellitus: A Basic Overview
Diabetes mellitus is a chronic condition characterized by abnormally raised levels of blood glucose. It is one of the most common conditions encountered in clinical practice and represents a significant burden on the health systems of the developed world. The management of diabetes mellitus is crucial as untreated type 1 diabetes would usually result in death. Poorly treated type 1 diabetes mellitus can still result in significant morbidity and mortality. The main focus of diabetes management now is reducing the incidence of macrovascular and microvascular complications.
There are different types of diabetes mellitus, including type 1 diabetes mellitus, type 2 diabetes mellitus, prediabetes, gestational diabetes, maturity onset diabetes of the young, latent autoimmune diabetes of adults, and other types. The presentation of diabetes mellitus depends on the type, with type 1 diabetes mellitus often presenting with weight loss, polydipsia, polyuria, and diabetic ketoacidosis. On the other hand, type 2 diabetes mellitus is often picked up incidentally on routine blood tests and presents with polydipsia and polyuria.
There are four main ways to check blood glucose, including a finger-prick bedside glucose monitor, a one-off blood glucose, a HbA1c, and a glucose tolerance test. The diagnostic criteria are determined by WHO, with a fasting glucose greater than or equal to 7.0 mmol/l and random glucose greater than or equal to 11.1 mmol/l being diagnostic of diabetes mellitus. Management of diabetes mellitus involves drug therapy to normalize blood glucose levels, monitoring for and treating any complications related to diabetes, and modifying any other risk factors for other conditions such as cardiovascular disease. The first-line drug for the vast majority of patients with type 2 diabetes mellitus is metformin, with second-line drugs including sulfonylureas, gliptins, and pioglitazone. Insulin is used if oral medication is not controlling the blood glucose to a sufficient degree.
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This question is part of the following fields:
- Endocrine System
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Question 27
Incorrect
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A 23-year-old woman is experiencing renal colic and is being evaluated for possible MEN IIa. What is the most common parathyroid gland abnormality associated with this condition?
Your Answer:
Correct Answer: Hyperplasia
Explanation:Medullary thyroid cancer, hypercalcaemia, and phaeochromocytoma are associated with multiple endocrine neoplasia type IIa. The most frequent occurrence in this condition is medullary thyroid cancer, while hyperplasia is the most common lesion in the parathyroid glands. In contrast, parathyroid adenoma is the most common lesion in MEN I.
Understanding Multiple Endocrine Neoplasia
Multiple endocrine neoplasia (MEN) is an autosomal dominant disorder that affects the endocrine system. There are three main types of MEN, each with its own set of associated features. MEN type I is characterized by the 3 P’s: parathyroid hyperplasia leading to hyperparathyroidism, pituitary tumors, and pancreatic tumors such as insulinomas and gastrinomas. MEN type IIa is associated with the 2 P’s: parathyroid hyperplasia leading to hyperparathyroidism and phaeochromocytoma, as well as medullary thyroid cancer. MEN type IIb is characterized by phaeochromocytoma, medullary thyroid cancer, and a marfanoid body habitus.
The most common presentation of MEN is hypercalcaemia, which is often seen in MEN type I due to parathyroid hyperplasia. MEN type IIa and IIb are both associated with medullary thyroid cancer, which is caused by mutations in the RET oncogene. MEN type I is caused by mutations in the MEN1 gene. Understanding the different types of MEN and their associated features is important for early diagnosis and management of this rare but potentially serious condition.
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This question is part of the following fields:
- Endocrine System
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Question 28
Incorrect
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A 10-year-old girl visits her pediatrician with her mother. She is worried that she hasn't started puberty yet while some of her classmates have.
The pediatrician explains to the young girl and her mother that the onset of puberty can vary and that it is considered delayed if there are no signs of puberty by the age of 13 years. The pediatrician reassures the girl that there is no need to worry and that she should be patient.
What is the first sign the girl should expect?Your Answer:
Correct Answer: Testicular enlargement
Explanation:The initial indication of male puberty is the growth of the testicles. This typically happens between the ages of 9.5 and 13.5 years and is the first sign of male puberty. Testicular enlargement is the only pubertal change present in Tanner stage 1.
During Tanner stage 2, which usually occurs between the ages of 10.5 and 14.5 years, penis growth begins.
Pubic hair development also starts during Tanner stage 2, between the ages of 9.9 and 14.0 years.
The height growth spurt occurs at age 14 and reaches a maximum of 10cm/year in Tanner.
The voice changes during Tanner stage 3, which typically happens around 13.5 years old.
Puberty: Normal Changes in Males and Females
Puberty is a natural process that marks the transition from childhood to adolescence. In males, the first sign of puberty is testicular growth, which typically occurs around the age of 12. Testicular volume greater than 4 ml indicates the onset of puberty. The maximum height spurt for boys occurs at the age of 14. On the other hand, in females, the first sign of puberty is breast development, which usually occurs around the age of 11.5. The height spurt for girls reaches its maximum early in puberty, at the age of 12, before menarche. Menarche, or the first menstrual period, typically occurs at the age of 13, with a range of 11-15 years. Following menarche, there is only a slight increase of about 4% in height.
During puberty, it is normal for boys to experience gynaecomastia, or the development of breast tissue. Girls may also experience asymmetrical breast growth. Additionally, diffuse enlargement of the thyroid gland may be seen in both males and females. These changes are all part of the normal process of puberty and should not be a cause for concern.
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This question is part of the following fields:
- Endocrine System
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Question 29
Incorrect
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A 67-year-old man has visited the doctor with concerns about his blood glucose levels. He has type 1 diabetes and also suffers from chronic obstructive pulmonary disease (COPD). Following a recent bout of pneumonia, he has been experiencing difficulty in managing his blood sugars. You suspect that one of his newly prescribed medications may be contributing to this issue. Which medication could be causing acute problems with diabetic control?
Your Answer:
Correct Answer: Prednisolone
Explanation:The use of corticosteroids, such as prednisolone, can have a negative impact on diabetic control due to their anti-insulin effects. This can cause an increase in glucagon levels, leading to elevated blood sugar levels. While this effect is usually temporary and should resolve on its own, higher doses of insulin may be necessary during treatment. Prednisolone is often prescribed to manage exacerbations of COPD.
Amoxicillin, a penicillin antibiotic, can be prescribed alongside prednisolone to treat infective asthma exacerbations. Its bactericidal effects are unlikely to affect diabetes control.
Carbocisteine is a mucolytic medication commonly used for long-term management of COPD and bronchiectasis. It helps to thin sputum in the lungs, making it easier to cough up and preventing colonization. It is not known to worsen diabetes control.
Doxycycline, a tetracycline antibiotic, is commonly used to treat COPD exacerbations. However, it does not typically affect blood sugar control and is unlikely to be a contributing factor in this case.
Corticosteroids are commonly prescribed medications that can be taken orally or intravenously, or applied topically. They mimic the effects of natural steroids in the body and can be used to replace or supplement them. However, the use of corticosteroids is limited by their numerous side effects, which are more common with prolonged and systemic use. These side effects can affect various systems in the body, including the endocrine, musculoskeletal, gastrointestinal, ophthalmic, and psychiatric systems. Some of the most common side effects include impaired glucose regulation, weight gain, osteoporosis, and increased susceptibility to infections. Patients on long-term corticosteroids should have their doses adjusted during intercurrent illness, and the medication should not be abruptly withdrawn to avoid an Addisonian crisis. Gradual withdrawal is recommended for patients who have received high doses or prolonged treatment.
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This question is part of the following fields:
- Endocrine System
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Question 30
Incorrect
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Release of somatostatin from the pancreas will lead to what outcome?
Your Answer:
Correct Answer: Decrease in pancreatic exocrine secretions
Explanation:Octreotide is utilized to treat high output pancreatic fistulae by reducing exocrine pancreatic secretions, although parenteral feeding is the most effective treatment. It is also used to treat variceal bleeding and acromegaly.
Octreotide inhibits the release of growth hormone and insulin from the pancreas. Additionally, somatostatin, which is released by the hypothalamus, triggers a negative feedback response on growth hormone.
Somatostatin: The Inhibitor Hormone
Somatostatin, also known as growth hormone inhibiting hormone (GHIH), is a hormone produced by delta cells found in the pancreas, pylorus, and duodenum. Its main function is to inhibit the secretion of growth hormone, insulin, and glucagon. It also decreases acid and pepsin secretion, as well as pancreatic enzyme secretion. Additionally, somatostatin inhibits the trophic effects of gastrin and stimulates gastric mucous production.
Somatostatin analogs are commonly used in the management of acromegaly, a condition characterized by excessive growth hormone secretion. These analogs work by inhibiting growth hormone secretion, thereby reducing the symptoms associated with acromegaly.
The secretion of somatostatin is regulated by various factors. Its secretion increases in response to fat, bile salts, and glucose in the intestinal lumen, as well as glucagon. On the other hand, insulin decreases the secretion of somatostatin.
In summary, somatostatin plays a crucial role in regulating the secretion of various hormones and enzymes in the body. Its inhibitory effects on growth hormone, insulin, and glucagon make it an important hormone in the management of certain medical conditions.
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This question is part of the following fields:
- Endocrine System
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