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Grey matter, or brain matter in American English, is a major component of the central nervous system, consisting of neuronal cell bodies, neuropil ( dendrites and unmyelinated axons ), glial cells ( astrocytes and oligodendrocytes ), synapses, and capillaries. Grey matter is distinguished from white matter in that it contains numerous cell ...
The neocortex consists of the grey matter, or neuronal cell bodies and unmyelinated fibers, surrounding the deeper white matter ( myelinated axons) in the cerebrum. This is a very thin layer though, about 2–4 mm thick. [ 6] There are two types of cortex in the neocortex, the proisocortex and the true isocortex.
Myelin. Myelin ( / ˈmaɪ.əlɪn / MY-ə-lin) is a lipid -rich material that surrounds nerve cell axons (the nervous system's electrical wires) to insulate them and increase the rate at which electrical impulses (called action potentials) pass along the axon. [ 1][ 2] The myelinated axon can be likened to an electrical wire (the axon) with ...
White matter is the tissue through which messages pass between different areas of grey matter within the central nervous system. The white matter is white because of the fatty substance (myelin) that surrounds the nerve fibers (axons). This myelin is found in almost all long nerve fibers, and acts as an electrical insulation.
Grey matter is composed of cell bodies, dendrites, unmyelinated axons, protoplasmic astrocytes (astrocyte subtype), satellite oligodendrocytes (non-myelinating oligodendrocyte subtype), microglia, and very few myelinated axons. White matter is composed of myelinated axons, fibrous astrocytes, myelinating oligodendrocytes, and microglia.
Gray ramus communicans; White ramus communicans; The grey and white rami communicantes are responsible for conveying autonomic signals, specifically for the sympathetic nervous system. Their difference in coloration is caused by differences in myelination of the nerve fibres contained within, i.e. there are more myelinated than unmyelinated ...
The white matter consists of axons and oligodendrocytes, while the gray matter consists of neurons and unmyelinated fibers. Both tissues include a number of glial cells (although the white matter contains more), which are often referred to as supporting cells of the CNS.
The grey columns, (three regions of grey matter) in the center of the cord, is shaped like a butterfly and consists of cell bodies of interneurons, motor neurons, neuroglia cells and unmyelinated axons. The anterior and posterior grey columns present as projections of grey matter and are also known as the horns of the spinal cord.