Cushing's syndrome is the result of hypersecretion of which gland?

Cushing's syndrome is specifically caused by the hypersecretion of cortisol, a steroid hormone produced by the adrenal cortex. In this condition, the body produces excessive levels of cortisol, which can result from various factors such as an adrenal tumor or overproduction by the pituitary gland due to a condition known as Cushing's disease, where there is an overproduction of adrenocorticotropic hormone (ACTH) that stimulates the adrenal cortex to release cortisol.

The adrenal cortex's role in the endocrine system is critical as it regulates metabolism, immune response, and stress response through the secretion of glucocorticoids like cortisol. Therefore, understanding the function of the adrenal cortex is essential for recognizing the implications of Cushing's syndrome, including its symptoms, such as weight gain, hypertension, and changes in skin appearance.

In contrast, the thyroid gland primarily regulates metabolism via hormones like thyroxine, the pancreas is involved in glucose metabolism and insulin production, and the hypothalamus plays a pivotal role in the regulation of hormonal secretions from the pituitary gland. Thus, while these other glands are essential for various bodily functions, they are not involved in the pathophysiology of Cushing's syndrome.