Mammal hormones

Testosterone is a steroid hormone found in mammals. Testosterone is primarily secreted in the testes of males and the ovaries of females, although small amounts are also secreted by the adrenal glands. It is the principal male sex hormone and an anabolic steroid. In men, testosterone plays a key role in the development of male reproductive tissues such as the testis and prostate as well as promoting secondary sexual characteristics such as increased muscle, bone mass and hair growth.

Epinephrine (also known as adrenaline) is a hormone and neurotransmitter. It increases heart rate, contracts blood vessels, dilates air passages and participates in the fight-or-flight response of the sympathetic nervous system. It is produced by the adrenal glands.