What is Adrenocorticotropic Hormone (ACTH)?

ACTH is a hormone produced by the anterior pituitary gland located at the base of the brain. It is part of the hypothalamic-pituitary-adrenal (HPA) axis, which is responsible for the body's response to stress and regulation of various physiological processes.

Functions of Adrenocorticotropic Hormone

• Stimulates the production and release of cortisol from the adrenal glands
• Plays a role in the body's response to stress and helps regulate metabolism, immune function, and blood pressure
• Regulates the growth and development of the adrenal cortex

Regulation of ACTH Release

The secretion of ACTH is controlled by the hypothalamus, specifically by the release of corticotropin-releasing hormone (CRH). CRH stimulates the pituitary gland to produce and release ACTH into the bloodstream. ACTH then acts on the adrenal glands to stimulate the production and release of cortisol.

Clinical Significance

Abnormal levels of ACTH can lead to various health conditions. For example, excessive production of ACTH can result in conditions such as Cushing's syndrome, characterized by high levels of cortisol in the body. On the other hand, low levels of ACTH can lead to adrenal insufficiency, causing symptoms such as fatigue, weakness, and low blood pressure.

Study Tips for Understanding ACTH

• Understand the role of the hypothalamus in regulating ACTH release
• Learn about the feedback mechanisms involved in the HPA axis
• Explore the clinical conditions associated with dysregulation of ACTH levels
• Review the physiological effects of cortisol and its regulation by ACTH