GENERAL HISTOLOGY

Detailed explanation-1: -Norepinephrine is a neurotransmitter used by part of the nervous system activated during stress called the sympathetic nervous system. The sympathetic nervous system is involved with regulating blood pressure and pulse rate.

Detailed explanation-2: -Sympathetic System; Overview The primary neurotransmitter in preganglionic sympathetic neurons is acetylcholine (ACh), which activates neurons in the sympathetic ganglion neurons and adrenal medulla via ganglion-type nicotinic ACh receptors.

Detailed explanation-3: -Its major site of storage and release are the neurons of the sympathetic nervous system (a branch of the autonomic nervous system). Thus, norepinephrine functions mainly as a neurotransmitter with some function as a hormone (being released into the bloodstream from the adrenal glands).

Detailed explanation-4: -As a hormone, stress triggers the release of norepinephrine from your adrenal glands. This reaction causes a number of changes in your body and is known as the fight-or-flight response.