BI459 Lecture Notes - Lecture 8: Preganglionic Nerve Fibers, Catecholamine, Stressor
Document Summary
Adrenal medulla: stimulated by sympathetic pre-ganglionic neurons, secretes ne/e for the regulation of the short-term (acute) stress response (fight or flight response) Function = to prepare the body for extreme physical exertion. Adrenal cortex: secretes steroid hormones important for the regulation of the long-term (chronic) stress response. The adrenal hormones induce changes in metabolism and/or ionic regulation that work to eliminate or neutralize the effects of the stressor. Stressors can be: physical, injury (pain), malnutrition, hypothermia, psychological, perception of threat, verbal flight, bad day at school glucocorticoid secretion. Only acute stressors that present an immediate threat to homeostasis result in rapid activation of the brain- sympathetic adrenal axis and catecholamine secretion. Both acute and moderate stressors activate the hypothalamic- pituitary adrenal axis and. Usually elevated for only a few minutes (short half-life) Immune suppression increase susceptibility to infections; decrease in wound healing. Childhood abuse has been associated with an increased adrenocorticotropic hormone response to stress.
