they need to have these specialized voltage-gated ion channels

细胞膜上必须有那些专用的
in their membranes.

电压门控离子通道
Cardiac myocytes have that,

心肌细胞上就有这种通道
they also have actin and myosin.

同时还有肌动蛋白和肌球蛋白
They're muscle cells and they're capable of contracting,

它们是肌细胞具有收缩功能
meaning that this myocyte here can shorten itself.

也就是说这些肌细胞可以自己缩短
It can make itself shorter by contracting just like a muscle,

这些细胞可以像骨骼肌一样可以收缩变短
a whole muscle contracts.

一个完整的收缩过程
That's different than neurons

这一点和神经元截然不同
so they have this capacity to transmit action potentials;

所以说它们不但可以传递动作电位
they have this capacity to contract.

它们也具有收缩功能
Now,in muscle cells,

在骨骼肌细胞中