Grey matter

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"Gray matter" redirects here. For the short story, see Gray Matter.
Grey matter
The formation of the spinal nerve from the dorsal and ventral roots. (Grey matter labeled at center right.)
Latin substantia grisea
Dorlands/Elsevier s_27/12766773

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).

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[edit] 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.

[edit] 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).

[edit] Function

The function of grey matter is to route sensory or motor stimulus to interneurons of the CNS for creation of response to 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.

[edit] References in fiction

Hercule Poirot created by the crime writer Agatha Christie referred to his "little grey cells" when he was actually referring to his brain, thought process and skills to deduce the motive or murderer in question so can also be used as a slang word for brains or the use of them.

[edit] See also

[edit] External links


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Histology: nervous tissue
Neurons (gray matter): soma, axon (axon hillock, axoplasm, axolemma, neurofibril/neurofilament), dendrite (Nissl body, dendritic spine)
types (bipolar, pseudounipolar, multipolar, pyramidal, Purkinje, granule)

Afferent nerve/Sensory nerve/Sensory neuron (GSA, GVA, SSA, SVA, Type Ia sensory fiber), Efferent nerve/Motor nerve/Motor neuron (GSE, GVE, SVE) Alpha motor neuron, Gamma motoneurons, Upper motor neuron, Lower motor neuron), Interneuron (Renshaw)

Synapses: neuropil, synaptic vesicle, neuromuscular junction, electrical synapse

Sensory receptors: Free nerve ending, Meissner's corpuscle, Merkel nerve ending, Muscle spindle, Pacinian corpuscle, Ruffini ending, Olfactory receptor neuron, Photoreceptor cell, Hair cell, Taste bud

Glial cells: astrocyte, ependymal cells, microglia, radial glia

Myelination (white matter): Schwann cell, oligodendrocyte, nodes of Ranvier, internode, Schmidt-Lanterman incisures, neurolemma

Related connective tissues: epineurium, perineurium, endoneurium, nerve fascicle, meninges
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