Noun. /ˈwaɪt ˌmæt̬.ɚ/
by Christine Side
What does it mean?
White matter is a type of tissue located deep in the brain and on the outer layer of the spinal cord. It is primarily made up of axons coated in myelin, a fatty coating that insulates neurons and allows electrical signals to travel faster. White matter helps the brain and spinal cord communicate and exchange information across different regions. The name comes from the light appearance of these areas, which is due to the myelin-coated axons.
How do I use it in a sentence?
Half of the human brain is composed of white matter, which sends signals generated by the cell bodies located in the gray matter.
Figure caption: (Left) A drawn coronal slice of the human brain at the thalamus with pointers to the cortical gray matter and the subcortical white matter. (Right) A drawn section of the spinal cord with pointers to the surface white matter and the deeper gray matter. Image created by author in BioRender.
History of usage
The word was first described by Andreas Vesalius in his treatise titled De Humani Corporis Fabrica in 1543.
Related terms
Gray matter, axon, myelin, subcortical, brain, spinal cord, neuroscience
