Adrenaline, also called epinephrine, is produced by the adrenal glands. The adrenal glands actually consist of two distinct regions: the adrenal cortex and the adrenal medulla. Each region produces different types of hormones. The adrenal medulla is responsible for the production of adrenaline.
Two adrenal glands are present in humans, and they lie atop the kidneys. The inner region of the adrenal gland is the medulla, and the outer portion is the cortex. The cortex releases corticoids and sex hormones.
The adrenal medulla consists of nerve cells that are part of the sympathetic nervous system, according to the MCB department at the University of California, Berkeley. These neurons release the neurotransmitter adrenaline directly into the bloodstream instead of into a synapse. In addition to adrenaline, norepinephrine and catecholamines are also produced by the adrenal medulla.