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myelin Syllabification: my·e·lin
Pronunciation: /ˈmīələn/

Definition of myelin in English:


Anatomy & Physiology
A mixture of proteins and phospholipids forming a whitish insulating sheath around many nerve fibers, increasing the speed at which impulses are conducted.
Example sentences
  • It turns out that the bacterium that causes leprosy directly damages a protective sheathing, made of the protein myelin, around many nerve cells.
  • They then manipulated them in the laboratory to turn them into specialised cells that form myelin, the insulating layer than surrounds nerve fibres.
  • For example, multiple sclerosis involves the progressive destruction of the myelin that insulates neural axons.


Pronunciation: /-ləˌnātəd/
Example sentences
  • Their content of myelinated nerve fibers indicates their origin as branches of the pelvic colonic innervation.
  • It also preserved many of the myelinated nerve fibers in treated animals, compared to untreated rats and those that did not receive the triple combination, the researchers found.
  • The incompletely myelinated frontal lobes of children only gradually join the grid of electrical activity that operates the brain.
Pronunciation: /ˌmīələˈnāSHən/
Example sentences
  • Other innovations in this group of animals include an adaptive immune system similar to that of humans, a closed and pressurized circulatory system, and myelination of the nervous system.
  • Hence, neuronal circuitry and myelination are disrupted.
  • Next are areas related to memory, then to spatial orientation and to comprehension of language and then we see myelination in language areas.


Late 19th century: from Greek muelos 'marrow' + -in1.

Definition of myelin in:
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