Cortisol Response ~ The synthesis of cortisol in the adrenal gland is stimulated by the anterior lobe of the pituitary gland with adrenocorticotropic hormone (ACTH); ACTH production is in turn stimulated by corticotropin-releasing hormone (CRH), which is released by the hypothalamus.
If a person has Cushing’s disease, it means that a group of abnormal cells has built up in the pituitary gland to form an ACTH-producing pituitary tumor. These abnormal cells produce ACTH, just as normal pituitary gland cells do—only far too much. The excess ACTH travels to adrenal glands. The adrenal glands are then bombarded with signals to produce more and more cortisol. As a result, the adrenal glands continuously secrete too much cortisol.
Cushing's syndrome describes the signs and symptoms associated with prolonged exposure to inappropriately high levels of the hormone cortisol. This can be caused by taking glucocorticoid drugs, or diseases that result in excess cortisol, adrenocorticotropic hormone (ACTH), or CRH levels.
The pituitary has two parts. The anterior lobe is the source of prolactin, GH, thyroid-stimulating hormone (TSH, controlling the thyroid), gonadotropic hormones (LH and FSH, controlling testes or ovaries) and adrenocorticotropic hormone (ACTH, controlling the adrenal glands). The posterior lobe contains nerve fibers coming from the brain (hypothalamus) storing oxytocin (necessary for uterine contractions during delivery) and anti-diuretic hormone.