Regarding syndrome of inappropriate antidiuretic hormone (SIADH), which is true?

Correct Answer: A

Rationale: In the syndrome of inappropriate antidiuretic hormone (SIADH), there is excessive secretion of antidiuretic hormone (ADH) leading to increased water reabsorption in the kidney tubules. This results in dilutional hyponatremia because the amount of water reabsorbed is greater than the electrolytes, such as sodium, leading to a relative decrease in their concentration in the blood. As a result, hyponatremia occurs in SIADH, contributing to symptoms such as nausea, confusion, and seizures due to the imbalance in electrolytes.

Correct Answer: D

Rationale: Ranitidine is not associated with an increased risk of osteoporosis in adults. It is a histamine-2 blocker commonly used to reduce stomach acid production and treat conditions such as ulcers and gastroesophageal reflux disease. On the other hand, the other options listed are known to increase the risk of osteoporosis:

Correct Answer: B

Rationale: Hashimoto's thyroiditis is an autoimmune disease where the immune system mistakenly attacks the thyroid gland. The antibodies produced by the immune system target the thyroglobulin in the thyroid gland, leading to its destruction over time. This results in decreased thyroid hormone production, leading to hypothyroidism. Therefore, choice B, "A destructive autoimmune disease caused by auto-reactive antibodies against thyroglobulin," best describes Hashimoto's thyroiditis.

Correct Answer: C

Rationale: The phrase "Cushing's disease" specifically refers to the cause of Cushing's syndrome that is due to an ACTH-secreting pituitary adenoma. In this specific case, the excess production of ACTH leads to bilateral adrenal hyperplasia and oversecretion of cortisol. It is important to differentiate between Cushing's syndrome caused by a pituitary adenoma (Cushing's disease) and other causes such as adrenal adenomas, ectopic ACTH production, or iatrogenic sources.

Correct Answer: A

Rationale: In the context of pharmacology and endocrinology, understanding the symptoms of hyperthyroidism is crucial for healthcare professionals to make accurate diagnoses and provide appropriate treatment. The correct answer is A) Tremor. Tremor is a common symptom of hyperthyroidism due to the increased metabolic rate and overstimulation of the sympathetic nervous system associated with an excess of thyroid hormones. Tremors are often seen in the hands and fingers of individuals with hyperthyroidism. Option B) Weight gain is incorrect because hyperthyroidism typically leads to weight loss, not weight gain. The increased metabolic rate causes individuals to burn calories at a faster rate, resulting in weight loss despite a normal or increased appetite. Option C) Heat intolerance is a common symptom of hyperthyroidism as the excess thyroid hormones can affect the body's thermoregulation, making individuals more sensitive to heat. This symptom is often accompanied by increased sweating. Option D) Diarrhea is not a common symptom of hyperthyroidism. While gastrointestinal symptoms such as diarrhea can occur in some cases, they are not as prevalent or characteristic of hyperthyroidism as tremors, weight loss, and heat intolerance. Educationally, understanding the specific symptoms of hyperthyroidism helps students and healthcare professionals differentiate it from other thyroid disorders such as hypothyroidism. This knowledge is essential for accurate diagnosis and management of patients with thyroid disorders, highlighting the importance of recognizing the hallmark signs and symptoms of hyperthyroidism like tremors.