The pyrethroid keeps the sodium channels open, so the nerves fire repeatedly.

拟除虫菊酯使钠离子通道保持开放，导致神经不断反射。

Genetic mutations have given them sodium channels that the pyrethroids can't bind to.

基因突变使它们拥有拟除虫菊酯无法结合的钠通道。

When blood pressure stretches arterial walls, that opens mechanically-gated sodium channels in these little receptors.

当血压拉伸动脉壁时，这些小受体中的机械门控钠通道就会打开。