Chromaffiinisolut

Chromaffiinisolut, also known as chromaffin cells, are specialized neuroendocrine cells found primarily in the adrenal medulla of the adrenal glands. These cells are responsible for the synthesis, storage, and secretion of catecholamines, namely epinephrine (adrenaline) and norepinephrine (noradrenaline). They are also found in smaller numbers in sympathetic ganglia and along the sympathetic nervous system chain.

The name "chromaffin" originates from their characteristic staining reaction with chromium salts. When exposed to these salts, the catecholamines within the cells are oxidized and polymerized, resulting in a brown coloration. This histochemical property was historically important for their identification and study.

Chromaffin cells develop from neural crest cells, migrating to the adrenal medulla during embryonic development. They are innervated by preganglionic sympathetic neurons, which release acetylcholine. Upon stimulation, these neurons trigger the release of catecholamines from the chromaffin cells into the bloodstream. This release is a key component of the body's "fight-or-flight" response, preparing the body for immediate action by increasing heart rate, blood pressure, and metabolic rate.

The hormones secreted by chromaffin cells have diverse physiological effects throughout the body. Epinephrine is a potent stimulator of the cardiovascular system and plays a role in glucose metabolism. Norepinephrine also affects blood pressure and heart rate, and it acts as a neurotransmitter in the central nervous system. The activity of chromaffin cells is tightly regulated by the sympathetic nervous system and other hormonal signals.