What are the bare gaps between stretches of myelin called, and how long are they compared with the insulated stretches? · Lobeworks/17

Nodes of Ranvier, about a micrometre long; the insulated stretches between them are internodes, typically about a hundred times the fibre's diameter, so from about a hundred micrometres to over a millimetre.

What are the bare gaps between stretches of myelin called, and how long are they compared with the insulated stretches?

Nodes of Ranvier, about a micrometre long; the insulated stretches between them are internodes, typically about a hundred times the fibre's diameter, so from about a hundred micrometres to over a millimetre. The sodium channels are packed at the nodes, and that is the only place the spike is regenerated.