Adrenal gland and paraganglia
Physiology - medulla

Topic Completed: 1 October 2013

Revised: 1 July 2019

Copyright: 2002-2019,, Inc.

PubMed Search: Adrenal medulla [title]

Pallav Gupta, M.D.
Page views in 2019 to date: 1
Cite this page: Gupta P. OLD Physiology - medulla. website. Accessed October 21st, 2019.
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)
Diagrams / tables

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Synthesis of catecholamines

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