Respiratory organ
To maintain life, we absorb oxygen from the air. And we export carbon dioxide from the body.
Human respiratory organs include the nose, organs, bronchi and lungs.
Each bronchus in the lung continues to diverge and taper. The end of this thin branch is connected to the alveoli. The alveoli are a very thin airbag.
Capillaries surround the surface of the alveoli. In alveolar gas exchange occurs between air and blood. Since the lungs consist of many alveoli, the surface area is extensive. Therefore, the exchange of gas between the air and the blood can occur quickly and easily.
Wrinkles found in living organisms
There are many wrinkles all over our body, such as the brain, lungs, intestines, tongue, and nasal passages. These folds are a way to fit as large a 2D area as possible in a small 3D space. In this way, it can increase efficiency.
Not only humans but many other creatures are wrinkled to increase the efficiency of material exchange. (ex: fish’s gills, plant root hairs…)