Endocrinology Exam Questions and Answers

Correct Answer: D

Rationale: Osteomalacia is a condition in which there is a softening of the bones due to a deficiency in vitamin D or calcium. It is not a cause of hypocalcemia, as it is a result of low levels of calcium in the bloodstream. The other options listed are potential causes of hypocalcemia:

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: Persistent muscular weakness is characteristic of myxoedema, which is severe hypothyroidism. Myxoedema can lead to general weakness and fatigue, as thyroid hormones play a crucial role in controlling metabolism and energy production in the body. Other symptoms of myxoedema include cold intolerance, weight gain, dry skin, and hair loss. Conn's syndrome (hyperaldosteronism) is characterized by hypertension and low potassium levels, not persistent muscular weakness. Acromegaly is a condition resulting from excess growth hormone production, leading to enlarged body parts and metabolic changes but not specifically muscular weakness. Hyperparathyroidism is associated with high levels of parathyroid hormone, which can lead to bone weakening and calcium imbalance, but it is not typically a primary cause of muscular weakness.

Correct Answer: A

Rationale: The most common cause of Cushing's disease is an ACTH-producing pituitary adenoma. In this condition, the pituitary gland produces excessive amounts of adrenocorticotropic hormone (ACTH), which stimulates the adrenal glands to produce high levels of cortisol. This leads to the signs and symptoms of Cushing's disease, such as weight gain, high blood pressure, and muscle weakness. Adrenocortical adenoma refers to a benign tumor of the adrenal cortex that can also cause Cushing's syndrome, but it is not as common as an ACTH-producing pituitary adenoma. Ectopic ACTH secretion occurs when a non-pituitary tumor produces ACTH, leading to Cushing's syndrome. McCune-Albright syndrome is a rare genetic disorder that can cause various endocrine abnormalities, but it is not a common cause of Cushing's disease.

Correct Answer: C

Rationale: Acromegaly is a rare hormonal disorder where excess growth hormone is produced, leading to the enlargement of bones and tissues. The prevalence of acromegaly is higher in men compared to women, with a ratio of about two men affected for every woman. This gender difference is believed to be due to the impact of sex hormones on the development and progression of the condition. While acromegaly can affect both men and women, men are more commonly diagnosed with the disorder.