When a neuron is not conducting any impulse, i.e., resting, the axonal membrane is comparatively more permeable to potassium ions (K+) and nearly impermeable to sodium ions.

What is resting axonal membrane?

During the resting potential, sodium channels are completely closed, but potassium channels are partly open, so potassium can flow slowly out of the neuron. As an action potential travels down the axon, there is a change in polarity across the membrane.

What is the resting membrane potential at axonal membrane?

A neuron at rest is negatively charged: the inside of a cell is approximately 70 millivolts more negative than the outside (−70 mV, note that this number varies by neuron type and by species).