Normal lung function The main function of the lungs is to bring oxygen-rich air into the body and expel carbon dioxide.
When air flows into the lungs, it is brought into close proximity with the blood, where oxygen diffuses into the body and carbon dioxide diffuses out.
This process, as simple as it sounds, requires an extraordinary coordination of air flow, or ventilation, and blood flow, or perfusion.
There are over 20 divisions in your airway, starting at the main windpipe, or the trachea, all the way out to the little balloons at the end of the airway, called alveoli, that are in close contact with your blood vessels.