myelin

noun

my·​e·​lin ˈmī-ə-lən 

: a soft white material that forms a thick layer around the axons of some neurons and is composed chiefly of lipids (such as cerebroside and cholesterol), water, and smaller amounts of protein

myelinic

ˌmī-ə-ˈli-nik 

adjective

Examples of myelin in a Sentence

Recent Examples on the Web

The disease affects the central nervous system, attacking the substance that protects nerve fibers (myelin), damaging nerves and disrupting communication between the brain and the body. —Jessie Opoien, Journal Sentinel, 22 May 2024

The immune system attacks the myelin, or protective sheath, that covers nerve fibers. —Kerry Breen, CBS News, 8 June 2024

Your body also needs the mineral to help make myelin, a protein that wraps protectively around nerve cells to help amplify all those signals. —Lizzy Briskin, SELF, 26 Mar. 2024

While the cause is unknown, MS attacks the central nervous system, creating lesions on the brain and spinal cord, and damaging the protective layer surrounding the nerve fibers, called myelin. —Andrew Abrahams, Peoplemag, 1 Mar. 2024

Word History

Etymology

borrowed from German Myelin, from Greek myelós "bone marrow" + German -in -in entry 1 — more at myelo-

Note: The term was introduced by Rudolf virchow in "Ueber das ausgebreitete Vorkommen einer dem Nervenmark analogen Substanz in den thierischen Geweben," Archiv für pathologische Anatomie und Physiologie und für klinische Medicin, 6. Band (1854), p. 571

First Known Use

1866, in the meaning defined above

Phrases Containing myelin

• myelin sheath

Kids Definition

myelin

noun

my·​elin

ˈmī-ə-lən

: a soft white somewhat fatty material that forms a thick layer around the axons of some neurons

Medical Definition

myelin

noun

my·​e·​lin ˈmī-ə-lən 

: a soft white material of lipid and protein that is secreted by oligodendrocytes and Schwann cells and forms a thick sheath about axons see myelin sheath

myelinic

ˌmī-ə-ˈlin-ik 

adjective