What Are the Functions of Adrenal Medulla?

The adrenal medulla is the inner core of the adrenal gland, one of which is located at the top of each kidney. Made up of masses of neurons, the medulla is part of the autonomic nervous system's sympathetic branch.

Primary Function

• The adrenal medulla, although part of the nervous system, functions as an endocrine gland, releasing the so-called stress hormones--epinephrine (adrenaline) and norepinephrine (noradrenaline)--into the bloodstream.

Functions of Epinephrine

• Released at times of stress, epinephrine quickens the heartbeat, strengthens the force of cardiac contractions, elevates blood pressure, constricts blood vessels, opens airways in the lungs and redistributes blood flow to vital organs.

Functions of Norepinephrine

• Like epinephrine, norepinephrine plays a role in the body's response to fight-or-flight stressors, but it also has been shown to be a significant factor in matters of attention and concentration.

Not Considered Essential

• Despite the role it plays in fight-or-flight situations, the adrenal medulla's function is not considered essential. "You don't need it to live," writes Kelly Rehan in an article on EndocrineWeb.

Adrenal Cortex

• The same cannot be said of the adrenal cortex, the outer layer of the gland. The cortex releases cortisol, which regulates metabolism, and aldosterone, involved in blood pressure regulation.