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

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See Examples For:

myelin sheath

These precursor cells can mature into oligodendrocytes, which produce the myelin sheath surrounding axons.

From Science Daily ● Aug. 14, 2026

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

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

From Science Daily ● Apr. 15, 2026

In both aging mice and mice mimicking MS, the ESI1 treatment prompted myelin sheath production and improved lost neurological function.

From Science Daily ● May 2, 2024

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