Chromaffin cells

Chromaffin cells are neuroendocrine cells found primarily in the adrenal medulla. They are derived from neural crest cells and function as modified postganglionic sympathetic neurons. They synthesize and store catecholamines (epinephrine ~80%, norepinephrine ~20%) in dense-core secretory granules. In response to stress signals (acetylcholine from preganglionic fibers), they release these hormones directly into the bloodstream to mediate the systemic "fight-or-flight" response.