Now that you’ve gotten to know the adrenal glands a bit, let’s go step-by-step through the fight-or-flight response. The acute stress response: playing hormone telephone Epinephrine is the principal hormone that interacts with the sympathetic nervous system in the initial part of the fight-or-flight response.įun fact: epinephrine and norepinephrine function both as hormones in the endocrine system and as neurotransmitters in the nervous system! In fact, norepinephrine is the main neurotransmitter of the sympathetic nervous system. The medulla produces epinephrine/adrenaline (E) and norepinephrine/noradrenaline (NE). Cortisol is a glucocorticoid released during the later part of the stress response. The cortex is composed of glandular epithelial tissue, whereas the medulla is made of nervous tissue.ĭifferent regions of the cortex produce a variety of different hormones, including mineralocorticoids (which affect water and mineral balance), glucocorticoids (which affect glucose levels), and gonadocorticoids (adrenal sex hormones).

Let's check out the adrenal glands in context in Visible Body Suite:Įach adrenal gland has two main parts: an outer cortex, which makes up the majority of the gland, and an internal medulla. You might also know the adrenal glands as the suprarenal glands for this reason-suprarenal literally means “above the kidney.' My colleagues here at VB like to refer to these guys as “the party hats of the kidneys,” which is a pretty apt description considering their fun pointy shape and the fact that there’s one sitting atop each kidney. When it comes to the body’s stress response, the adrenal glands are the stars of the show. Today, we’re going to talk about both of these types of stress-the classic fight-or-flight response as well as what happens when your body experiences persistent stress. It can really do damage to the body over time. Once the danger has passed, the body goes back to business as usual.Ĭhronic stress, on the other hand, happens when the body is constantly responding to stress and remaining in a heightened state for a long time. The fight-or-flight (or fight-flight-freeze) response, aka the “alarm” stage of the stress response, is there for a good reason-it prepares the body to deal with danger (you know, like outrunning a ferocious animal that’s trying to eat you, or fighting off a fellow cave-person coming at you with a spear).

So, what is stress? At its core, stress is all about how the body reacts to a potential threat. Most of us spend a lot of time either feeling it, trying to relieve it, or both. Stress is a pretty big deal in modern society.

The Endocrine System: The Adrenal Glands and the Stress Response

Adrenal cortex hormones and functions