Adrenal gland and paraganglia
Physiology - medulla

Author: Pallav Gupta, M.D. (see Authors page)

Revised: 8 August 2017, last major update October 2013

Copyright: (c) 2002-2017,, Inc.

PubMed Search: Adrenal medulla [title]

Table of Contents
Definition / general
Cite this page: Physiology - medulla. website. Accessed October 17th, 2018.
Definition / general
  • Synthesizes and secretes primarily catecholamines (norepinephrine and epinephrine) in response to signals from preganglionic nerve fibers in sympathetic nervous system
  • Norepinephrine: local transmitter, chiefly of sympathetic postganglionic neurons
  • Epinephrine: systemic transmitter, interacts with alpha and beta adrenergic receptors
  • See also Anatomy
  • Cells are called chromaffin cells or pheochromocytes
  • Innervated by axons from lower thoracic and lumbar preganglionic neurons via splanchnic nerves
  • Dopamine, which is precursor of norepinephrine, is found in adrenal medulla and peripheral sympathetic nerves and acts as a neurotransmitter in CNS
  • Catecholamines affect cardiovascular and metabolic processes, causing increase in heart rate, blood pressure, myocardial contractility and cardiac conduction velocity (Williams Textbook of Endocrinology)

Synthesis of catecholamines