medullary Definition

of or relating to the pith of a plant

of or relating to a medulla and especially the medulla oblongata

a primary tissue composed of radiating bands of parenchyma cells extending between the vascular bundles of herbaceous dicotyledonous stems and connecting the pith with the cortex

vascular ray

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