The air tubes branching off the end of trachea?

The air tubes branching off the end of the trachea are called bronchi. The trachea is the main airway that carries air from the mouth and nose to the lungs. When the trachea reaches the lungs, it branches into two tubes called the primary bronchi. The primary bronchi then branch into smaller tubes called the secondary bronchi, which then branch into even smaller tubes called the tertiary bronchi. The tertiary bronchi end in tiny air sacs called alveoli, which are where gas exchange occurs between the air and the blood.