Grey matter

Template:Infobox Anatomy Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

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).

## Contents

* 1 Composition
* 2 Distribution
* 3 Function
* 4 See also
* 5 External links

## Composition

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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

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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

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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. Research has shown that the amount of gray matter in a brain is positively correlated with human intelligence. (Andreason & Others, 1994)

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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* Gray matter heterotopia
* Neuropil
* Rexed laminae
* substantia nigra
* White matter

## External links

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* Template:EMedicineDictionary

* v
* t
* e

Nervous tissue

CNS|

| Tissue Types|

* Grey matter
* White matter
* Projection fibers
* Association fiber
* Commissural fiber
* Lemniscus
* Nerve tract
* Decussation
* Commissure
* Neuropil
* Meninges

|

Cell Types|

| Neuronal|

* Pyramidal
* Purkinje
* Granule
* Spindle
* Interneuron

|

Glial|

| insulating:|

* Myelination: Oligodendrocyte

|

other|

* Astrocyte
* Ependymal cells
* Tanycyte
* Microglia

PNS|

| General|

* Dorsal
* Root
* Ganglion
* Ramus
* Ventral
* Root
* Ramus
* Ramus communicans
* Gray
* White
* Autonomic ganglion (Preganglionic nerve fibers
* Postganglionic nerve fibers)
* Nerve fascicle
* Funiculus

|

Connective tissues|

* Epineurium
* Perineurium
* Endoneurium

Neuroglia|

* Myelination: Schwann cell
* Neurilemma
* Myelin incisure
* Node of Ranvier
* Internodal segment
* Satellite glial cell

Neurons/
nerve fibers|

| Parts|

| Soma|

* Axon hillock

|

Axon|

* Telodendron
* Axon terminals
* Axoplasm
* Axolemma
* Neurofibril/neurofilament

Dendrite|

*     * Nissl body
* Dendritic spine
* Apical dendrite/Basal dendrite

Types|

* Bipolar
* Unipolar
* Pseudounipolar
* Multipolar
* Interneuron
* Renshaw

Afferent nerve fiber/
Sensory neuron|

* GSA
* GVA
* SSA
* SVA
* fibers
* Ia or Aα
* Ib or Golgi or Aα
* II or Aβ and Aγ
* III or Aδ or fast pain
* IV or C or slow pain

Efferent nerve fiber/
Motor neuron|

* GSE
* GVE
* SVE
* Upper motor neuron
* Lower motor neuron
* α motorneuron
* β motorneuron
* γ motorneuron

Termination|

| Synapse|

* Electrical synapse/Gap junction
* Chemical synapse
* Synaptic vesicle
* Active zone
* Postsynaptic density
* Autapse
* Ribbon synapse
* Neuromuscular junction

|

Sensory receptors|

* Meissner's corpuscle
* Merkel nerve ending
* Pacinian corpuscle
* Ruffini ending
* Muscle spindle
* Free nerve ending
* Nociceptor
* Olfactory receptor neuron
* Photoreceptor cell
* Hair cell
* Taste bud

Template:Spinal cord

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