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.

    • ‘It turns out that the bacterium that causes leprosy directly damages a protective sheathing, made of the protein myelin, around many nerve cells.’
    • ‘For example, multiple sclerosis involves the progressive destruction of the myelin that insulates neural axons.’
    • ‘They then manipulated them in the laboratory to turn them into specialised cells that form myelin, the insulating layer than surrounds nerve fibres.’
    • ‘They travel to the brain and mount an assault on a substance called myelin, which acts as a protective sheath around nerve fibers.’
    • ‘The neurologic symptoms are a result of destruction of myelin, though axons may also be affected.’


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