Medicine & BodyGreek → English
Myelin
/ˈmaɪəlɪn/noun
The fatty sheath that wraps nerve fibres and speeds the signals along them.
The Greek roots
μυελός
myelós
marrow
Literally: “marrow substance”
Follow a root:μυελός4 words
The story of the word
Rudolf Virchow named the substance in 1854 after μυελός, marrow, because the pale fatty stuff squeezing out of a cut nerve looked like marrow to him. It is not marrow, and generations of students have been misled by the label. The same root sits inside poliomyelitis, literally inflammation of the grey marrow, which is what ancient anatomy called the spinal cord.
- How it travelled
- Ancient Greek → scientific coinage → German → English
- First recorded
- 1850s
Same family
myelomapoliomyelitisosteomyelitis
In a sentence
Multiple sclerosis attacks myelin, and the signals slow down or stop.
Myelin keeps forming into a person's twenties, which is part of why reaction times improve.