Corticotropin-releasing hormone (CRH) released by the hypothalamus stimulates the pituitary corticotropic cells to secrete ACTH (adenocorticotrope hormone). ACTH stimulates the adrenal cortex, especially the zona fasciculata that produces glucocorticoids like cortisol.
Cortisol has a negative feedback action on CRH secretion from the hypothalamus and ACTH secretion from the pituitary. Glucocorticoids have many effects, e.g. on glucose metabolism and the immune system.
I. ACTH stimulates adrenaline secretion from the adrenal gland.
II. Chronic stress affects ACTH levels.
Extra info: ACTH stimulates only the cortex of the adrenal gland, especially the production of cortisol. Chronic stress affects the hypothalamus-pituitary-adrenal system: usually ACTH and cortisol levels are elevated.
The adrenal medulla produces the hormones