medulla, adrenal

medulla, adrenal The innermost portion of the adrenal gland, which makes epinephrine (adrenaline) and norepinephrine (noradrenaline). These hormones cause the breakdown of the storage product glycogen to the sugar glucose in the liver, facilitate the release of fatty acids from adipose (fat) tissue, cause narrowing (constriction) of most blood vessels in the body, and increase the output of the heart.