Showing results for myelin sheath. Search instead for Myelin+Sheath.

myelin sheath

American

noun

Anatomy.

a wrapping of myelin around certain nerve axons, serving as an electrical insulator that speeds nerve impulses to muscles and other effectors.

Etymology

Origin of myelin sheath

First recorded in 1895–1900

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

MS is a disease of the brain and central nervous system, in which the immune system mistakenly attacks the fatty myelin sheath that normally protects the nerves, like insulation around electric wires.

From BBC • May 29, 2026

These metabolites support the growth and maturation of oligodendrocytes, which in turn helps rebuild the myelin sheath.

From Science Daily • Apr. 15, 2026

To test this idea, Zhang and his team examined whether the mutation could protect the myelin sheath.

From Science Daily • Apr. 15, 2026

The myelin sheath is a protective coating that surrounds nerve fibers in the brain and spinal cord.

From Science Daily • Apr. 15, 2026

The thicker this myelin sheath, the faster the transmission.

From Science Daily • Mar. 6, 2024

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023