Endocrinology Exam Questions and Answers

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: B

Rationale: ADH (antidiuretic hormone), also known as vasopressin, is secreted by the posterior lobe of the pituitary gland. ADH plays a key role in regulating water balance in the body by controlling the reabsorption of water in the kidneys. When the body senses a decrease in blood volume or an increase in blood osmolarity, ADH is released to signal the kidneys to conserve water, leading to concentrated urine production and water retention in the body.

Correct Answer: D

Rationale: Medullary carcinoma of the thyroid typically presents with symptoms related to the thyroid gland itself, neck mass or swelling, and sometimes cervical lymphadenopathy. It is characterized by the production of calcitonin, leading to high serum calcitonin levels. Carcinoid syndrome, which includes symptoms such as flushing, diarrhea, and wheezing, is more commonly associated with neuroendocrine tumors, rather than medullary carcinoma of the thyroid. Psychosis is not a typical feature or manifestation of medullary carcinoma of the thyroid.

Correct Answer: B

Rationale: The triad of hyponatremia (low sodium levels in the blood), haemodilution (increased plasma volume), and urine hypertonic to plasma (high urine osmolality compared to blood osmolality) is characteristic of Syndrome of Inappropriate Antidiuretic Hormone (SIADH). In SIADH, there is excessive release of antidiuretic hormone (ADH), also known as vasopressin, leading to water retention by the kidneys and dilutional hyponatremia. This condition results in the body holding onto water, causing hyponatremia and dilution of the blood. The urine being hypertonic compared to plasma indicates that the kidneys are reabsorbing water effectively and concentrating the urine.

Correct Answer: D

Rationale: Acromegaly is typically caused by the overproduction of growth hormone (GH) by the pituitary gland. In around 95% of cases, this overproduction is due to the presence of a non-cancerous tumor called a pituitary adenoma. These adenomas are benign, slow-growing tumors that cause the pituitary gland to produce excessive amounts of growth hormone, leading to the characteristic symptoms of acromegaly such as enlargement of the bones and soft tissues.