人体显微照片：当精子遇上卵子

9.肺气泡 Alveoli in the lung


肺气泡

This is what a colour-enhanced image of the inner surface of your lung looks like. The hollow cavities are alveoli; this is where gas exchange occurs with the blood.

　　这张彩色图片显示的是人类肺部内表面。图中的洞穴是肺气泡，这里是血液交换气体的地方。