During the ARP, although some voltage-gated Na+ channels can open, this is counterbalanced by an increased conductance to K⁺ ions across the membrane.

During the ARP, all voltage-gated Na⁺ channels are refractory and closed.

Neurons never receive a second very strong stimulus during the ARP to allow all the voltage-gate channels to open..

During the ARP, the Na⁺/K⁺ pump is too active to allow Na⁺ to depolarise the membrane to threshold for an AP.

During the ARP, only some voltage-gated Na⁺ channels are refractory and closed but these are the ones specifically responsible for APs.