AIRWAYS;
TRACHEA; BRONCHUS; BRONCHI; BRONCIOLES
ALVEOLI

Air enters the lung through the trachea (or windpipe). Air quickly branches into the left and right bronchus (pleural: bronchi). Each bronchus branches into many smaller airways called bronchioles. The alveoli are the small air filled sacs at the end of the air passages. The alveoli are surrounded by small capilliaries that allow the exchange of oxygen and carbon dioxide between the air and blood.

This entire pathway is referred to as the airway.

Image 1: Airways

Image 2: Alveoli