Medical Dictionary

myelin sheath

noun

Medical Definition of MYELIN SHEATH

:  the insulating covering that surrounds an axon with multiple spiral layers of myelin, that is discontinuous at the nodes of Ranvier, and that increases the speed at which a nerve impulse can travel along an axon—called also medullary sheath
April 25, 2015
lissome Hear it
nimble or easily flexed
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