For example, after menopause, estrogen production stops, which leads to death of the alveolar cells.

例如，经后，雌激素止，会导腺细胞死亡。

As a result, during every menstrual cycle, the alveolar cells undergo division and apoptosis.

因此，在每一个月经周期中，腺细胞都会经历裂增殖和凋亡的阶段。

Without these hormones, the glandular cells, particularly the alveolar cells, cannot survive, and undergo apoptosis which is programmed cell death.

如果没有这些激素，腺体细胞，尤其是腺细胞将无法存活，并会凋亡，即程序性死亡。

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

巨噬细胞之后会吞噬这些红细胞，导这些细胞由于铁元素积聚而呈现棕褐色。

As you can see below, small capillaries press up against the respiratory zone, bringing the blood close to the alveolar air.

正如你在下面所看到的，小毛细血管挤压着紧贴呼吸区，携带血液紧靠气。

The respiratory membrane separates the alveolar air on one side from the blood on the other.

呼吸膜将一侧的空气与另一侧的血液离。

As you can see, oxygen moves out of the alveolar air into the blood, and carbon dioxide moves out of the blood into the alveolar air.

正如你看到的，氧气气移出进入血液，二氧化碳血液中移入气。

Just like healthy alveolar cells, some breast cancer cells have hormone receptors that allow them to grow in the presence of the hormones.

就像健康的腺细胞一样，一些乳腺癌细胞也有激素受体，会使它们在激素作用下生长。

As blood flows through the pulmonary capillaries, oxygen diffuses into the blood and carbon dioxide diffuses into the alveolar gas.

当血液流过毛细血管时，氧气扩散到血液中，二氧化碳扩散到气体中。

As you can see in the picture above, the partial pressure of carbon dioxide in the alveolar air is about 40 mmHg.

如上图所示，空气中二氧化碳的压约为40 mmHg。

Bacterial growth and death of alveolar macrophages produce powerful chemotactic factors that cause a large influx of polymorphonuclear leukocytes and monocytes from the peripheral blood.

军团菌的增长及巨噬细胞的死亡产生了强大的趋化因子，造成大量多形核白细胞和单核细胞外周血涌入。

The partial pressure of oxygen is 100 mmHg in alveolar air compared to only 40 mmHg in the blood entering the lungs.

空气中的氧压为100 mmHg，而进入部的血液中只有40 mmHg。

The partial pressure of carbon dioxide is 40 mmHg in the alveolar air and 45 mmHg in the blood entering the lungs.

空气中的二氧化碳压为40 mmHg，进入部的血液中的二氧化碳压为45 mmHg。

This respiratory surface, also known as the respiratory membrane, includes the alveolar epithelial cells as well as the pulmonary capillary endothelial cells.

呼吸表面，也称为呼吸膜，包括上皮细胞和毛细血管内皮细胞。

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，此时气道被称为管，而不是呼吸性细支气管。

Zooming in on the alveoli, there’s a layer of alveolar cells that secrete breast milk into the lumen which is the space in the center of the gland.

放大腺来看，这里有一层腺细胞向腔内乳汁。

The respiratory membrane is very thin, as it consists of only two cells - that is, the alveolar epithelial cell and the pulmonary capillary cell.

呼吸膜很薄，因为它只有两个细胞，即上皮细胞和毛细血管细胞。

So the alveolar wall, the basement membrane, and the capillary wall is really all that separates the air from the blood, and this is called the blood-gas barrier.

所以，壁、基底膜和毛细血管壁将空气和血液离，这个结构叫气血屏障。

Carbon dioxide diffuses in the opposite direction since the partial pressure is greater in the blood entering the lungs than it is in the alveolar air.

二氧化碳向相反方向扩散，因为进入部血液中的压比空气中的压大。

Since the partial pressure of oxygen is lower in the blood entering the lungs than it is in the alveolar gas, oxygen diffuses into the blood.

由于进入部的血液中的氧压低于气体中的氧压，因此氧气扩散到血液中。