Class 11 NEET Biology Chemical Coordination and Integration

Norepinephrine is released from the adrenal medulla into the blood as a hormone and is also a neurotransmitter in the central nervous system and sympathetic nervous system. An increase in norepinephrine from the sympathetic nervous system increases the rate of contractions in the heart. Norepinephrine also underlies the fight-or-flight response, along with epinephrine, directly increasing heart rate, triggering the release of glucose from energy stores, and increasing blood flow to skeletal muscle.
Prolactin is a hormone produced by the anterior portion of the pituitary gland.
Vasopressin's two primary functions are to retain water in the body and to constrict blood vessels. It regulates the body's retention of water by acting to increase water reabsorption in the collecting ducts of the nephron.
Glucagon is a peptide hormone, produced by alpha cells of the pancreas, that raises the concentration of glucose in the bloodstream.