Endocrinology Exam Questions and Answers

Correct Answer: A

Rationale: Dermal hyperpigmentation, also known as hyperpigmentation of the skin, is commonly associated with conditions such as Addison's disease, hemochromatosis, and bronchogenic carcinoma. In Addison's disease, there is increased production of melanin due to elevated levels of adrenocorticotropic hormone (ACTH) which stimulates melanocytes. Hemochromatosis can cause hyperpigmentation due to excess iron deposits in the skin. Bronchogenic carcinoma can lead to a condition known as acanthosis nigricans, characterized by dark, velvety discoloration of the skin primarily around the neck and armpits. However, Conn's syndrome, which is a primary aldosteronism resulting from an adrenal adenoma or hyperplasia, is not typically associated with dermal hyperpigmentation.

Correct Answer: B

Rationale: Postmenopausal estrogen therapy has been shown to have a protective effect on bone density and reduce the risk of osteoporosis-related fractures, including hip fractures. Estrogen therapy helps to maintain bone strength and reduce the chances of fractures in postmenopausal women. Therefore, estrogen therapy does not increase the risk of hip fractures; in fact, it may decrease the risk of hip fractures in this population.

Correct Answer: A

Rationale: Primary hyperparathyroidism is a condition characterized by the overproduction of parathyroid hormone (PTH) by the parathyroid glands, leading to elevated levels of calcium in the blood. This excessive calcium can cause calcification in various tissues, including the basal ganglia of the brain. The calcification of the basal ganglia in primary hyperparathyroidism is a well-known radiological finding and can be visualized on imaging studies such as CT scans or MRI. Hypoparathyroidism, on the other hand, is characterized by low levels of PTH and results in decreased serum calcium levels, making it an unlikely cause of basal ganglia calcification. Secondary hyperparathyroidism is associated with chronic kidney disease and is also characterized by high PTH levels, but basal ganglia calcification is not a typical manifestation of this condition. Milk-alkali syndrome is a disorder characterized by excessive intake of

Correct Answer: D

Rationale: Blood calcium levels are primarily regulated by the actions of parathyroid hormone (PTH) and Vitamin D. Vitamin D plays a crucial role in maintaining calcium balance in the body by promoting the absorption of calcium from the intestines. When blood calcium levels are low, Vitamin D works to increase absorption of calcium to raise the levels back to normal. Therefore, elevated blood calcium levels are commonly associated with excess Vitamin D intake or conditions that increase Vitamin D levels, such as hypervitaminosis D.

Correct Answer: A

Rationale: Hypertonicity (increased osmolarity or high concentration of solutes in the blood) is the most potent stimulus for the hypothalamic production of arginine vasopressin (also known as antidiuretic hormone or ADH). When the body senses increased plasma osmolality, the osmoreceptors in the hypothalamus stimulate the release of vasopressin from the posterior pituitary gland. Vasopressin acts on the kidneys to increase water reabsorption and decrease urine output, helping to restore normal osmolarity. This mechanism helps to conserve water and maintain body fluid balance in response to dehydration or increased solute concentration in the blood.