Editing Node of Ranvier (section)

===Action potential===
An [[action potential]] is a spike of both positive and negative ionic discharge that travels along the membrane of a cell.<ref>{{cite journal | last1 = Fry | first1 = C | doi = 10.1016/j.mpsur.2007.07.007 | title = Cell physiology I | journal = Surgery (Oxford) | year = 2007 | volume = 25 | issue = 10 | pages=425–429 | s2cid = 57536809 }}</ref>  The creation and conduction of action potentials represents a fundamental means of communication in the nervous system.  Action potentials represent rapid reversals in voltage across the plasma membrane of axons.  These rapid reversals are mediated by voltage-gated ion channels found in the [[plasma membrane]]. 
The action potential travels from one location in the cell to another, but [[ion flow]] across the membrane occurs only at the nodes of Ranvier. As a result, the action potential signal jumps along the axon, from node to node, rather than propagating smoothly, as they do in axons that lack a myelin sheath. The clustering of voltage-gated sodium and potassium ion channels at the nodes permits this behavior.