Epinephrine (also known as adrenaline) is a hormone and a neurotransmitter. It increases heart rate, constricts blood vessels, dilates air passages and participates in the fight-or-flight response of the sympathetic nervous system. Chemically, adrenaline is a catecholamine, a monoamine produced only by the adrenal glands from the amino acids phenylalanine and tyrosine.
The term adrenaline is derived from the Latin roots ad- and renes and literally means "on the kidney", in reference to the adrenal gland's anatomic location on the kidney. The Greek roots epi means on top of, while "Nephros" refers to the kidneys. These roots combined create adrenaline which roughly translates to "pertaining to on top of the kidneys" which is also the anatomical location of the adrenal glands. The term epinephrine is often shortened to epi in medical jargon.
Epinephrine is released during sexual arousal and it plays a very important role in orgasm. It has also the function to maintain the heart beat rate to keep the sexual arousal. It is produced by the adrenal glands and it is used during extensive exercise and maintaining bodily functions. Other functions and secretions are discussed in the article.
Adrenal extracts containing adrenaline were first obtained by Polish physiologist Napoleon Cybulski in 1895. These extracts, which he called nadnerczyna, contained adrenaline and other catecholamines. Japanese chemist Jokichi Takamine and his assistant Keizo Uenaka independently discovered adrenaline in 1900. In 1901, Takamine successfully isolated and purified the hormone from the adrenal glands of sheep and oxen. Adrenaline was first synthesized in the laboratory by Friedrich Stolz and Henry Drysdale Dakin, independently, in 1904.