myelin sheath

Từ điển WordNet v3.1 - WordNet Dictionary

noun

a layer of myelin encasing (and insulating) the axons of medullated nerve fibers
• Syn:
medullary sheath
• Hypernyms:
sheath, case
• Part Holonyms:
medullated nerve fiber, myelinated nerve fiber
• Substance Meronyms:
myelin, myeline, medulla
• Part Meronyms:
axolemma, Ranvier's nodes, nodes of Ranvier, oligodendroglia, oligodendria