Myelins

Part of speech: noun

Definitions

1. A type of lipid-rich substance that forms a protective sheath around nerve fibers, facilitating the rapid transmission of electrical impulses
2. A crucial component of the nervous system, providing insulation to neurons and helping in the efficient conduction of signals
3. An essential material in neural anatomy, enabling swift communication between nerve cells by enveloping axons with a fatty layer

Etymology: The word "myelins" is simply the plural of "myelin," so it names the many sheaths of insulating fatty tissue that wrap nerve fibres. "Myelin" itself was formed from the combining form "myelo-," drawn from the Ancient Greek "muelos," meaning "marrow," plus the chemical-sounding suffix "-in." The Greek word for marrow is the same one that gives the bone-marrow sense, and it lies behind the name of the substance because myelin was first recognised in nervous tissue, which was once thought to be closely related to the marrow of the spinal column. The "-in" ending is a common way of naming substances in chemistry and biology, so the word is a scientific coinage built from classical parts rather than something that passed down through ordinary speech. Its pieces therefore show a deliberate choice: an older Greek word for the soft inner matter of bones, applied to a new discovery in the nervous system.

Synonyms: nerve sheathes, myelin sheaths