myelin

[ mahy-uh-lin ]

noun

, Biology.

1. a soft, white, fatty material in the membrane of Schwann cells and certain neuroglial cells: the substance of the myelin sheath.

myelin

/ ˈmaɪɪlɪn; ˈmaɪɪˌliːn /

noun

1. a white tissue forming an insulating sheath ( myelin sheath ) around certain nerve fibres. Damage to the myelin sheath causes neurological disease, as in multiple sclerosis

myelin

/ mī′ə-lĭn /

1. A whitish, fatty substance that forms a sheath around many vertebrate nerve fibers. Myelin insulates the nerves and permits the rapid transmission of nerve impulses. The white matter of the brain is composed of nerve fibers covered in myelin.

Derived Forms

• ˌmyeˈlinic, adjective

Other Words From

• mye·linic adjective

Word History and Origins

Origin of myelin¹

First recorded in 1865–70; myel- + -in ²

Example Sentences

Some researchers suspect that antiviral treatments would probably make the most sense when used early on, before the immune system eats away at the myelin around the nerve cells.

From Science News

Enteric glia help the gut digest food, for instance, and a type of glia called Schwann cells, sisters to the brain’s oligodendrocytes, spread myelin on peripheral nerves to help speed signals along.

From Science News

In MS, the amount and quality of myelin is abnormal, replaced by “sclerotic” plaques, the hallmark of the disease.

From The Daily Beast

This loss of usable myelin results in poor nerve-to-nerve coordination, resulting is a slightly haywire main dashboard.

From The Daily Beast

Between the neurolemma and the axis cylinder is the medullated sheath, composed of a fatty substance known as myelin.

From Project Gutenberg

Alveolar cells commonly contain fat-droplets and, less frequently, myelin globules.

From Project Gutenberg