white matter

views updated Jun 08 2018

white matter That part of the nervous system which is composed mainly of the fibres or axons of nerve cells, most of which are covered by whitish, fatty sheaths (composed of myelin), hence appearing white in freshly-cut brain or spinal cord. The axons in the white matter are responsible for conducting information from and to the nerve cell bodies that are concentrated in the grey matter.

See myelin; nerves.

white matter

views updated May 14 2018

white matter Tissue of the central nervous system which is composed mainly of axons of neurons surrounded by myelin sheaths, which give rise to the white appearance. Compare GREY MATTER.

white matter

views updated Jun 11 2018

white matter Part of the tissue that makes up the central nervous system of vertebrates. It consists chiefly of nerve fibres enclosed in whitish myelin sheaths. Compare grey matter.

white matter

views updated May 21 2018

white matter n. nerve tissue of the central nervous system that is paler in colour than the associated grey matter because it contains more nerve fibres and thus larger amounts of myelin.