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Stress response
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Anything that pushes the body out of balance, physical or psychological, sets off the stress response. That internal balance is called homeostasis, and the response exists precisely to get it back.
What is interesting is that there is not one response but two, and they arrive at different moments. The fast one runs through the sympathetic-adrenal-medullary axis: the sympathetic nervous system signals the adrenal gland, and the gland releases catecholamines, the family that adrenaline belongs to.
The slow one runs through a chain of hormones, the hypothalamic-pituitary-adrenal axis. The hypothalamus releases CRH, the pituitary answers with ACTH, and the adrenal cortex secretes cortisol.
Think of two alarms on different timers: one goes off immediately and the other sounds only after a while. When stress becomes chronic, that system stops helping and the responses turn dysfunctional.
In brief
Any physical or psychological stimulus that disrupts homeostasis triggers a stress response.
It has two components: a fast one through the sympathetic-adrenal-medullary axis, which makes the adrenal gland release catecholamines, and a slow one through the hypothalamic-pituitary-adrenal axis.
Two alarms on different timers: one goes off immediately and the other takes a while to arrive.
In the slow axis the hypothalamus releases CRH, the pituitary responds with ACTH, and the adrenal cortex secretes cortisol.
The goal is to restore homeostasis, but chronic stress leads to dysfunctional responses.
Sources (1)
- National Center for Biotechnology Information, StatPearls PublishingPhysiology, Stress Reaction, StatPearlsPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
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