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NODE OF RANVIER--SPEEDS NERVE IMPULSE CONDUCTION, MYELINATED NERVE FIBERS IN A NERVE, LONGITUDINAL SECTION, 250X. The Nodes of Ranvier appear as constrictions in the Myelin Sheath The NERVE FIBER is reddish and the MYELIN SHEATH is represented by the white space surrounding the fiber. Nodes of Ranvier are uninsulated areas with many ion channels. They promote SALTATORY ("jumping") CONDUCION of the nerve impulse where the nerve impulse seems to jump from node to node instead of the continuous conduction in unmyelinated nerve fibers. Conduction is faster in these myelinated fibers.