At the end of each branch is a tiny air sac called an alveolus.

在每个分支的末端都有一个叫做肺泡的小气囊。

Because alveoli serve as critical exchange points between the blood and air from the outside world, they have their own specialized types of white blood cells, or macrophages, which defend against foreign organisms by enveloping and eating them.

因为肺泡相当于血和来自体外的空气的一个临界交换，拥有专门的白血细胞，又名巨噬细胞，这种细胞通过包络和吞噬外来细胞来进行防御。

Once it reaches the lungs, it gets ingested by alveolar macrophages and inside macrophages, it gets wrapped up in a vesicle called phagosome, which normally merges with lysosomes to kill invading bacteria.

进入肺内后，就会被肺泡巨噬细胞吞噬；在巨噬细胞内，被包裹在称为吞噬体的囊泡中，通常吞噬体会与溶酶体合，清除入侵的细菌。

Gas exchange in the lungs, so oxygen moving from the alveoli into the blood and carbon dioxide from the blood into the alveoli are both great examples of diffusion.

肺部进行气体交换，因此氧气从肺泡进入血和二氧化碳从血进入肺泡都是扩散的很好的例子。

It then fills the alveoli, tiny air sacs that enable the exchange of oxygen and carbon dioxide between the lungs and blood.

然后填充肺泡，微小的空气囊能使氧气和二氧化碳在肺部和血交换。

The alveoli are tiny air sacs that look like tiny clumps of grapes, that are wrapped up in a net of capillaries.

肺泡是微小的气囊，看起来像小丛葡萄，包裹于毛细血管网中。

Both of your lungs contain about 700 million alveoli, which together provide an amazing 75 square meters of moist membrane surface area.

你的两个肺包含大约 7 亿肺泡，共同提供了惊人的 75 平方米的湿膜表面积。

Alveolar macrophages then eat up these red blood cells, which causes them to take on this brownish color from iron build-up.

肺泡巨噬细胞后会吞噬这些红细胞，导致这些细胞由于铁元素积聚而呈现棕褐色。

They represent tiny air-sacs or alveoli getting filled with fluid, and turning a shade of grey on a CT scan.

这代表着肺泡中充满体，从而在CT显像中呈现灰色阴影。

And if there's one thing your body hates, it's a bunch of exotic material spicing up your sensitive alveoli!

如果有你身体讨厌的东西进来的话，就是一堆有毒的东西让你的肺泡激动起来了！

Free from particles, the inhaled air is now in the alveolus surrounded by mostly type I pneumocytes.

移出异物后，肺泡中的空气周围围绕的大多是I型肺泡细胞。

Initially, doctors had no way to alter the stretchability or squeeziness of their patients' air sacs.

最初，医生没有办法改变病人肺泡的拉伸性或挤压力度。

Eventually the respiratory bronchioles ends when there are nothing but alveoli, and at that point the airway is called an alveolar duct rather than a respiratory bronchiole.

最终呼吸性细支气管结束于肺泡，此时气道被称为肺泡管，而不是呼吸性细支气管。

The body also tries to force the fluid out of the alveoli through coughing.

身体也试图通过咳嗽，使那些体脱离肺泡。

As alveoli are responsible for gas exchange, this is not good news.

由于肺泡负责气体交换，这可不是好消息。

It has the ability to stop phagolysosomal fusion, and survive and replicate inside alveolar macrophages.

可以阻止吞噬体和溶酶体合，从而在肺泡巨噬细胞内生存并增殖。

There's a layer of Saran Wrap that's holding all those alveoli together, and then there's a layer against the chest wall, and there's a space between the lungs and the ribcage.

有一层保鲜膜将所有肺泡包裹在一起，然后有一层紧靠胸壁，在肺部和胸腔有一个空。

Because that's because each sac contains a cluster of alveoli, these tiny cavities lined with super thin, wet membranes made of simple squamous epithelium tissue.

因为这是因为每个囊包含一簇肺泡，这些微小的空腔内衬着由简单鳞状上皮组织制成的超薄湿膜。

The immune system releases additional white blood cells in the alveoli to help.

免疫系统也会在肺泡中释放出更多的白血细胞去帮忙。

That problem happens deep in the lungs, in tiny air sacs called alveoli, which exchange carbon dioxide for oxygen.

这个问题出现在肺部深处，叫做肺泡的微小气囊中，肺泡是将二氧化碳转化为氧气的部位。