my·​e·​lin | \ ˈmī-ə-lən How to pronounce myelin (audio) \

Definition of myelin

: 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

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Other Words from myelin

myelinic \ ˌmī-​ə-​ˈli-​nik How to pronounce myelinic (audio) \ adjective

Examples of myelin in a Sentence

Recent Examples on the Web

But when myelin becomes inflamed, perhaps due to a virus, that signal gets disrupted. Erik Lacitis, The Seattle Times, "Mysterious paralyzing illness leaves Washington families reeling," 19 Oct. 2018 The immune systems eats away at the fatty sheathing that covers and protects the nerve fibers in these areas (myelin). Carolyn L. Todd, SELF, "What Selma Blair 'Thought Was a Pinched Nerve' Turned Out to Be MS," 22 Oct. 2018 Helping that signal travel so fast is insulating material called myelin that covers the nerve cells in the spinal cord. Erik Lacitis, The Seattle Times, "Mysterious paralyzing illness leaves Washington families reeling," 19 Oct. 2018 Glial cells, among other things, build sheaths of a fatty material called myelin, which acts as an insulator to isolate the electrical activity of nerve impulses. John Timmer, Ars Technica, "The genetics of education: 1,271 genes account for 10% of the variation," 25 July 2018 This coating, made of a substance called myelin, protects our nerves and speeds up those vital electrical pulses moving from one neuron to the next, kissing across synaptic gaps in a brisk burst of chemicals. Aaron Gilbreath, Longreads, "The Inward Empire," 27 June 2018 In cells that make myelin, the substance that insulates and protects nerves, an abundance of sulfatides destroys tissue throughout the brain, spinal cord, and other parts of the nervous system. Vibhav Rangarajan, STAT, "The ‘cruel joke’ of compassionate use and right to try: Pharma companies don’t have to comply," 5 June 2018 The ragged extensions of an oligodendrocyte can supply many neurons (nerve cells) with myelin, an insulating material which allows each neuron's communicating axon to transmit electrical impulses efficiently. Doug Criss, CNN, "5 things for March 28: North Korea & China, Sacramento, water park death, new organ," 28 Mar. 2018 Drugs like inhalants can change the structure of the nervous system by destroying myelin: the fatty substance that coats the nerves like insulation. Stmichaelschool,, "St. Michael School Hosts Info Night and Open House: Community Voices," 13 Jan. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'myelin.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of myelin

1866, in the meaning defined above

History and Etymology for myelin

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Time Traveler for myelin

The first known use of myelin was in 1866

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More Definitions for myelin


my·​e·​lin | \ ˈmī-ə-lən How to pronounce myelin (audio) \

Medical Definition of myelin

: 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

Other Words from myelin

myelinic \ ˌmī-​ə-​ˈlin-​ik How to pronounce myelinic (audio) \ adjective

More from Merriam-Webster on myelin Encyclopedia article about myelin

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