Adrenaline, also known as epinephrine by its International Common Denomination (INN), is a hormone and a neurotransmitter. [1] Increases heart rate, constricts blood vessels, dilates the airways, and participates in the fighting reaction or escape from the sympathetic nervous system [2] Chemically, adrenaline is a catecholamine, a monoamine produced only by the adrenal glands from the amino acids phenylalanine and tyrosine. Adrenaline is the neurotransmitter that is released from the adrenal medulla, while norepinephrine is released from the paravertebral ganglia.