Library · Molecule
Adrenaline
Make it clearer
Adrenaline, also called epinephrine, is a hormone. It is made by cells with a name of their own, the chromaffin cells, which live in the adrenal medulla: the inner part of the adrenal gland, the one that sits on top of each kidney. From there the hormone is released into the blood and travels throughout the body.
For it to have an effect, every organ has locks that it fits into, the adrenergic receptors, which come in two kinds: alpha and beta. When there is little adrenaline, it is mainly the beta receptors that switch on, and they widen the bronchi, the tubes air comes in through, and stimulate the heart.
That is why, when something startles you, the heart beats faster, blood sugar goes up, more blood reaches skeletal muscle and less reaches the intestine.
Picture one signal that travels through the blood and reaches several organs at once. There is no need to notify each one separately: the same molecule travels around the body and each organ does its part.
In brief
Adrenaline, or epinephrine, is a catecholamine made mainly by the chromaffin cells of the adrenal medulla and released into the blood as a hormone.
It acts on alpha and beta adrenergic receptors depending on the dose: a low dose activates mainly the beta receptors, which dilate the bronchi and stimulate the heart.
When a threat appears, heart rate and blood sugar rise, more blood reaches skeletal muscle and less reaches the digestive tract.
One signal that travels through the blood and reaches several organs at once.
Sources (2)
- National Center for Biotechnology Information, StatPearls PublishingPhysiology, Catecholamines, StatPearlsPublished
- National Center for Biotechnology Information, StatPearls PublishingEpinephrine, StatPearlsPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
Updated