Medullary Chromaffin Cell

Medullary Chromaffin Cell

Chromaffin cells are neuroendocrine cells found in the medulla of the adrenal gland (suprarenal gland, located above the kidneys) and in other ganglia of the sympathetic nervous system. They are modified post-synaptic sympathetic neurons that receive sympathetic input. Instead of releasing neurotransmitter (catecholamines - ~20% Norepinephrine (Noradrenaline) and ~80% Epinephrine (Adrenaline)) to an adjacent organ or tissue for a specific effect, neurotransmitter is released into systemic circulation for systemic effects on multiple organs. Hence they are called neuroendocrine cells.

In the fifth week of (human) fetal development, neuroblast cells migrate from the neural crest to form the sympathetic chain and preaortic ganglia. The cells migrate a second time to the adrenal medulla. Chromaffin cells also settle near the sympathetic ganglia, vagus nerve, paraganglia, and carotid arteries. In lower concentrations, extra-adrenal chromaffin cells also reside in the bladder wall, prostate, and behind the liver.