Final answer:
The release of adrenocorticotropic hormone (ACTH) is stimulated by corticotropin-releasing hormone (CRH) from the hypothalamus in response to stress, leading to the secretion of cortisol. Short-term and long-term stress responses involve different mechanisms, with ACTH being central to the longer-term regulation of stress effects in the body.
Step-by-step explanation:
The release of adrenocorticotropic hormone (ACTH) is a crucial element in the body's response to stress. The physiological and psychological stressors initiate a cascade of hormonal signals starting with the hypothalamus. The hypothalamus secretes corticotropin-releasing hormone (CRH), which then stimulates the anterior pituitary gland to release ACTH. In turn, ACTH activates the adrenal glands to secrete corticosteroids, including cortisol, which plays a significant role in managing stress responses.
During a short-term stress response, the sympathetic nervous system triggers the adrenal medulla to release epinephrine and norepinephrine, facilitating the fight-or-flight response. Conversely, the long-term stress response involves the HPA axis, where ACTH promotes the secretion of glucocorticoids. These hormones assist in maintaining energy levels by catalyzing the breakdown of stored nutrients into usable forms. While beneficial in the short term, prolonged exposure to high levels of cortisol can lead to adverse health effects, including a weakened immune system and increased susceptibility to illness.