The adrenal medulla secretes epinephrine (also called adrenaline) and norepinephrine (also called noradrenaline). Epinephrine makes up 75 to 80 percent of the secretions from the adrenal medulla, with norepinephrine accounting for the remainder. These hormones are similar to those released by the sympathetic nervous system, but their effects last longer because they remain in the blood for longer periods of time.