ganglion

/ˈgæŋgliən/

/ˈgæŋgliən/

Other forms: ganglia; ganglions

In medicine, a ganglion is a cluster of nerve cells. Although it's not related to nerve cells, a harmless but visible lump on the skin is known as a ganglion cyst.

It's not uncommon for people to get benign but annoying ganglion cysts on their hands as they age. This use of ganglion goes back to the Greek root meaning "knot, swelling under the skin, or tumor." Ganglion came to mean "nerve cells" in medical terminology by the 17th century (although the cyst meaning also stuck around). Humans have many ganglia in their bodies, including the clusters around our spinal nerves and the basal ganglia in our brains.

Definitions of ganglion

1. noun

   an encapsulated neural structure consisting of a collection of cell bodies of neurons
   types:

   autonomic ganglion

   any of the ganglia of the autonomic system whose unmyelinated fibers innervate the internal organs

   basal ganglion

   any of several masses of subcortical grey matter at the base of each cerebral hemisphere that seem to be involved in the regulation of voluntary movement

   otic ganglion, otoganglion

   an autonomic ganglion whose postganglionic fibers are distributed to the parotid gland

   amygdala, amygdaloid nucleus, corpus amygdaloideum

   an almond-shaped neural structure in the anterior part of the temporal lobe of the cerebrum; intimately connected with the hypothalamus and the hippocampus and the cingulate gyrus; as part of the limbic system it plays an important role in motivation and emotional behavior

   caudate, caudate nucleus

   a tail-shaped basal ganglion located in a lateral ventricle of the brain

   claustrum

   a layer of grey matter in the brain adjacent to the lenticular nucleus

   lenticular nucleus, lentiform nucleus

   a basal ganglion shaped like a lens and including the outer reddish putamen and the inner pale yellow pallidum

   globus pallidus, paleostriatum, pallidum

   the inner pale yellow part of the lenticular nucleus

   putamen

   the outer reddish part of the lenticular nucleus

   corpus striatum, striate body, striatum

   a striped mass of white and grey matter located in front of the thalamus in each cerebral hemisphere; consists of the caudate nucleus and the lenticular nucleus

   type of:

   neural structure

   a structure that is part of the nervous system