The head of a Roman snail, four tentacles well visible. [RN] Observing a snail crawling around, the view is immediately attracted by its head, orienting itself in its surroundings using the tentacles. The snail feels its environment, touches an obstacle and withdraws the tentacle.
One of these hormones is epinephrine, which can be defined as a hormone secreted by the adrenal medulla in response to short-term stress. Epinephrine is also called adrenaline, and you may have heard of this term before.
Norepinephrine is also a naturally occuring hormone and neurotransmitter produced by your adrenal glands. The medication works similar to epinephrine (adrenaline): Both are vasopressors that constrict blood vessels and increase blood pressure and heart rate. Norepinephrine is injected into your vein through an IV.