Endocrinology Practice Questions

Correct Answer: B

Rationale: Correct Answer: B (Rheumatic carditis) Rationale: 1. Rheumatic carditis is a heart condition, which may lead to a decreased cardiac output and subsequently a lower pulse rate during sleep. 2. Anxiety neurosis can lead to increased sympathetic activity, causing an elevated pulse rate during sleep. 3. Pulmonary tuberculosis can cause systemic inflammation and increased metabolic demand, resulting in an elevated pulse rate during sleep. 4. Atropine, a parasympatholytic drug, inhibits the action of the parasympathetic nervous system, leading to an increased pulse rate.

Correct Answer: C

Rationale: Diabetes insipidus is a condition where the kidneys are unable to conserve water, leading to the excretion of large volumes of dilute urine. This is due to either a lack of antidiuretic hormone (ADH) production (central DI) or the kidneys' insensitivity to ADH (nephrogenic DI). Choice A is incorrect as the urine is dilute, not concentrated. Choice B is incorrect as diabetes insipidus results in large, not small, urine volumes. Choice D is incorrect as the urine is dilute, not concentrated. Therefore, choice C accurately describes diabetes insipidus.

Correct Answer: B

Rationale: The correct answer is B: Intranasal vasopressin may be helpful. In diabetes insipidus, there is a deficiency of vasopressin leading to excessive urination and thirst. Administering vasopressin intranasally can help replace the deficient hormone, reducing urine output and thirst. Hypernatremia (choice A) can occur due to excessive water loss, but it is not always present. There is no osmolar gap (choice C) in diabetes insipidus. Urine specific gravity (choice D) is typically low in diabetes insipidus due to the dilute urine produced.

Correct Answer: C

Rationale: The correct answer is C: Bi-temporal hemianopia. Pituitary adenoma compressing the optic chiasm typically leads to bi-temporal hemianopia due to compression of the crossing fibers from the nasal visual fields. This results in loss of peripheral vision in both temporal visual fields. A: Bilateral inferior visual field deficits and B: Bilateral superior visual field deficits are less likely as they are not typical patterns associated with optic chiasm compression. D: Right homonymous hemianopia is incorrect as it is not associated with compression of the optic chiasm by a pituitary adenoma.

Correct Answer: C

Rationale: Increased parathyroid hormone (PTH) concentration is associated with tetany because PTH helps regulate calcium levels in the blood. When calcium levels are low, PTH is released to stimulate the release of calcium from bones and increase calcium absorption from the intestines. Tetany is characterized by muscle cramps and spasms due to low calcium levels, which can occur when PTH levels are elevated. A: Vitamin D toxicity is associated with high levels of calcium in the blood, not low calcium levels as seen in tetany. B: Rickets is a condition caused by vitamin D deficiency, leading to impaired bone growth and development, not directly related to elevated PTH levels. D: Reduced excretion of phosphate is not directly linked to elevated PTH levels, as PTH primarily regulates calcium levels.