| Paraganglion | |
|---|---|
 Paraganglion ofgallbladder | |
| Identifiers | |
| TH | H3.08.02.8.00001 |
| FMA | 15648 |
| Anatomical terms of microanatomy | |
Aparaganglion (pl. paraganglia) is a group of non-neuronal cells derived of theneural crest. They are named for being generally in close proximity tosympathetic ganglia. They are essentially of two types: (1) chromaffin or sympathetic paraganglia made ofchromaffin cells and (2) nonchromaffin or parasympathetic paraganglia made ofglomus cells. They areneuroendocrine cells, the former with primaryendocrine functions and the latter with primarychemoreceptor functions.[1]
Chromaffin paraganglia (also called chromaffin bodies) are connected with theganglia of thesympathetic trunk and the ganglia of theceliac,renal,adrenal,aortic andhypogastric plexuses. They are concentrated near theadrenal glands and essentially function the same way as the adrenal medulla. They are sometimes found in connection with the ganglia of othersympathetic plexuses. None have been found with the sympathetic ganglia associated with the branches of thetrigeminal nerve. The largest chromaffin paraganglion is theorgan of Zuckerkandl, it is probably the largest source of circulating catecholamines in the fetus and young infants, and gradually atrophies to microscopic loci.[1]
Nonchromaffin paraganglia includecarotid bodies andaortic bodies, some are distributed in theear, along thevagus nerve, in thelarynx and at various other places.[2]
Tumors of the paraganglionic tissues are known asparagangliomas, though this term tends to imply the nonchromaffin type, and can occur at a number of sites throughout the body.
Chromaffin paragangliomas are issued from chromaffin cells, and are known aspheochromocytomas. Adrenal pheochromocytomas are usually benign while extra-adrenal ones are more malignant.[3] They are most of the time in the adrenals, and only rarely outside of the abdomen. They usually secrete hormones and estimates of a familial history vary.[1][2]
Nonchromaffin paragangliomas are usually benign.[3] They are generally present at the head and neck, most often at carotid body or jugulo-tympanic, they rarely secrete hormones and commonly have a familial history.[1][2]
This article incorporates text in thepublic domain frompage 1277 of the 20th edition ofGray's Anatomy(1918)
