'Grey matter' (or 'gray matter') is a major component of the
central nervous system, consisting of nerve cell bodies, glial cells (
astroglia and
oligodendrocytes), capillaries, and short nerve cell extensions/processes (
axons and
dendrites).
Composition
Grey matter is composed of unmyelinated neurons as opposed to
white matter (
myelinated neurons). It has a grey brown color which comes from the
capillary blood vessels and the neuronal cell bodies.
Distribution
Grey matter is distributed at the surface of the
cerebral hemispheres (
cerebral cortex) and of the
cerebellum (
cerebellar cortex), as well as in the depth of the cerebral (
thalamus;
hypothalamus;
subthalamus,
basal ganglia -
putamen,
globus pallidus,
nucleus accumbens;
septal nuclei), cerebellar (deep cerebellar nuclei -
dentate nucleus,
globose nucleus,
emboliform nucleus,
fastigial nucleus),
brainstem (
substantia nigra,
red nucleus,
olivary nuclei,
cranial nerve nuclei) and
spinal white matter (
anterior horn,
lateral horn,
posterior horn).
Function
The function of grey matter is to route sensory or motor stimulus to
interneurons of the CNS in order to create a response to the stimulus through
chemical synapse activity.
Grey matter structures (cortex, deep nuclei) process information originating in the
sensory organs or in other grey matter regions. This information is conveyed via specialized nerve cell extensions (long
axons), which form the bulk of the
cerebral,
cerebellar, and
spinal white matter.
See also
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White matter
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Neuropil
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Gray matter heterotopia
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Rexed laminae
External links
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