what is the purpose of nodes of ranvier in a neuron?:confused:

Node of Ranvier:

These are the gaps between the glial cells that make up the myelin sheath. The exchange of sodium only occurs at the Nodes of Ranvier in cells with a myelin sheath .

if you are interested in more information....more detailed info then check out:

http://www.rwc.uc.edu/Koehler/biophys/4d.html

it spells it out completely....but you may need a bit of background info in neurology to understand. Hope it answers your question.