The adrenal medulla secretes norepinephrine, also called noradrenaline.
Stress and emergency conditions cause it to be released. Norepinephrine and epinephrine raise blood sugar levels by increasing heart rate, and respiration rate, and stimulating glycogen, lipid, and protein breakdown for energy.
Norepinephrine is a neurotransmitter that regulates alertness, arousal, and attention in the brain and spinal cord.
Constricts blood vessels, which aids in the maintenance of blood pressure during stressful situations.
Sleep-wake cycle, emotions, and memory are all influenced.
The brain and body are mobilized for action when norepinephrine is released. In the so-called fight-or-flight response, norepinephrine levels are lowest during sleep, rise during alertness, and reach significantly higher levels under stressful or dangerous conditions.