Then, they face the respiratory tract's first-line defense: the mucociliary escalator.

粘膜纤毛自动扶梯。

But some of these invaders may get past the mucociliary escalator into the lungs, where they meet the alveoli.

但是有些入侵者有可能通过粘膜纤毛自动扶梯并进入到肺里，并接触到肺泡。

One of the body's first lines of defence against airborne pathogens is known as the " mucociliary clearance mechanism" .

人体抵抗空气传播病原体的第一道防线被称为“黏液纤毛清除机制”。

The mucociliary escalator consists of mucus that traps invaders and tiny hairs called cilia that carry the mucus toward the mouth, where it can be coughed out.

粘膜纤毛自动扶梯由困住入侵者的粘液和一些细小的毛发组成，这些毛发叫做纤毛，负责把粘液运送至嘴巴，使它们可以被咳出去。

With thick mucus, though, it gets a lot harder to clear and the mucociliary action becomes defective, which means bacteria is allowed to chronically colonize the lungs.

当黏液厚重时，粘液纤毛作用就变得困难起来，细菌得以在肺内长期繁殖。

Normally the cilia, these hair-like projections lining the airways, do a pretty good job of keeping the them clean by moving mucus, which catches things like debris and bacteria, toward the pharynx, called mucociliary action.

一般情况下，纤毛像毛发一样排列在气道内，在排送黏液、保持气道清洁方面有很大的作用，它们将捕获了污垢和细菌的黏液向咽部排送，这就是粘液纤毛作用。

For example, we have mechanical techniques like coughing, a mucociliary escalator that lines the entire airway and moves out larger bacteria, and macrophages that are nestled deep inside the alveoli and ready to destroy anything that lands there.

例如，我们有像咳嗽这样的技能，贴在气道的黏膜纤毛可移除较大的细菌，而巨噬细胞则在肺泡深处准备吞噬降解那里的东西。