From Wikipedia, the free encyclopedia
- "Gray matter" redirects here. For the short story, see Gray Matter.
| Grey matter |
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| The formation of the spinal nerve from the dorsal and ventral roots. (Grey matter labeled at center right.) |
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| 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).
[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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Anatomy of torso (primarily): the spinal cord |
| epidural space, dura mater, subdural space, arachnoid mater, subarachnoid space, pia mater, denticulate ligaments
conus medullaris, cauda equina, filum terminale, cervical enlargement, lumbar enlargement, anterior median fissure
spinal nerve: dorsal root, dorsal root ganglion, dorsal ramus, ventral root, ventral ramus, sympathetic trunk, ramus communicans (gray, white)
gray matter: central canal, substantia gelatinosa of Rolando, reticular formation, substantia gelatinosa centralis, interneuron, anterior horn, lateral horn, posterior horn (column of Clarke, dorsal spinocerebellar tract)
white matter: anterior funiculus: descending (anterior corticospinal tract, vestibulospinal fasciculus, tectospinal tract), ascending (anterior spinothalamic tract, anterior proper fasciculus)
lateral funiculus: descending (lateral corticospinal tract, rubrospinal tract, olivospinal tract), ascending (dorsal spinocerebellar tract, ventral spinocerebellar tract, spinothalamic tract, lateral spinothalamic tract, anterior spinothalamic tract, spinotectal tract, posterolateral tract, lateral proper fasciculus, medial longitudinal fasciculus
posterior funiculus: fasciculus gracilis, fasciculus cuneatus, posterior proper fasciculus
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