What are the 4 main functions of ACTH?

1. ACTH stimulates the adrenal cortex and causes the secretion gluco­corticoids.

2. Gluco-corticoid is a very essential hormone for an individual to meet the stressful conditions. When an animal is faced with a stressful situa­tion, impulses from the sense organs pass to the brain and then to the hypothalamus. The hypothalamus intern influences adenohypophysis to secrete more quantity of ACTH.

3. Melanocyte pigmentation is also under the control of ACTH and pa­tients in whom there is insufficiency of adrenal secretion are abnormally pigmented as a result of the loss of negative feedback provided by Corti­sol. This condition is known as Addison’s disease.


4. There is a diurnal variation in the secretion of ACTH. As a result of this, the Cortisol levels in the plasma will be at its peak in the morning (about 6 am) and will reach their lowest level around midnight. In an abnormality known as Cushing’s disease there is hypersecretion of Corti­sol and the diurnal variation is lost.