Adrenal Glands: Anatomy and the adrenal cortex Adrenal Cortex The outer layer of the adrenal gland. The activity of the adrenal medulla is regulated by the sympathetic nervous system. Derived from ectoderm, adrenal medulla consists mainly of chromaffin cells that produces and stores a number of neurotransmitters, mainly adrenaline (epinephrine) and norepinephrine. Adrenal Glands: Anatomy, the adrenal medulla Adrenal Medulla The inner portion of the adrenal gland. Beneath the cortex lies the adrenal medulla, which secretes catecholamines involved in the fight-or-flight response. The outer parenchyma is called the adrenal cortex and has 3 distinct zones, each with its own secretory products. There are 2 primary portions of the adrenal glands Adrenal Glands The adrenal glands are a pair of retroperitoneal endocrine glands located above the kidneys.