Adrenocorticotropic hormone

Definition

Adrenocorticotropic hormone (ACTH) is a peptide hormone produced by the anterior pituitary gland that stimulates the adrenal cortex to release cortisol, a vital hormone involved in stress response and metabolism regulation. It plays a crucial role in the hypothalamic-pituitary-adrenal (HPA) axis, influencing various physiological processes, including immune response and energy metabolism.

5 Must Know Facts For Your Next Test

1. ACTH is released in response to corticotropin-releasing hormone (CRH) from the hypothalamus, activating the HPA axis during stress situations.
2. The primary function of ACTH is to stimulate the adrenal cortex to produce cortisol, which helps the body manage stress and maintain homeostasis.
3. High levels of ACTH can indicate conditions such as Cushing's disease or Addison's disease, highlighting its importance in diagnosing endocrine disorders.
4. ACTH secretion follows a diurnal rhythm, peaking in the early morning and declining throughout the day, which influences cortisol levels in the body.
5. Understanding ACTH's role can help explain age-related changes in cortisol production and how these changes impact overall health and disease susceptibility.

Review Questions

• How does adrenocorticotropic hormone influence the stress response in the body?
  • Adrenocorticotropic hormone (ACTH) is crucial for initiating the body's stress response by stimulating the adrenal cortex to produce cortisol. This process begins when the hypothalamus releases corticotropin-releasing hormone (CRH), which prompts the anterior pituitary to secrete ACTH. The resulting increase in cortisol levels helps mobilize energy reserves and modulate immune functions, enabling the body to respond effectively to stressors.
• Evaluate the implications of abnormal ACTH levels on health and how they relate to specific endocrine disorders.
  • Abnormal levels of adrenocorticotropic hormone (ACTH) can significantly affect health, as they are often indicators of underlying endocrine disorders. For example, elevated ACTH levels may suggest Cushing's disease, where excessive cortisol production leads to various symptoms like weight gain and hypertension. Conversely, low ACTH levels can be associated with Addison's disease, resulting in insufficient cortisol production, fatigue, and low blood pressure. Recognizing these patterns is essential for accurate diagnosis and treatment planning.
• Synthesize information about how aging impacts the production and regulation of adrenocorticotropic hormone and its effects on overall health.
  • As individuals age, there are notable changes in the regulation and secretion of adrenocorticotropic hormone (ACTH), which can affect overall health. Research indicates that older adults may experience altered HPA axis function leading to variations in cortisol production. These age-related shifts can influence various aspects of health, including increased susceptibility to stress-related illnesses and chronic diseases. Understanding this relationship helps highlight the need for tailored health interventions for older populations to manage stress effectively and maintain hormonal balance.

Related terms

Cortisol: A steroid hormone produced by the adrenal cortex that helps regulate metabolism, immune response, and stress response.

Pituitary Gland: A small gland located at the base of the brain, responsible for producing various hormones, including ACTH, that regulate numerous body functions.

Hypothalamus: A region of the brain that links the nervous system to the endocrine system, playing a key role in regulating the release of ACTH through corticotropin-releasing hormone (CRH).