Those last three are called latent pacemakers, and they have slower depolarization rates - which is the rate at which they fire off electrical signals - and they get slower as you move further down.

后三者被称为潜在起搏点，他们的去极化速率更慢（在这个速率下它们发射电信号）向下级更远处传导时，它们会变得更慢。