what body part is the main trunk of the system of tubes by which air passes to and from your lungs? main-stem bronchus
Eventually, the bronchi become known as bronchioles â the smallest air tubes in the lungs. This system of air tubes can be thought of as an upside down tree, with the trachea being the main trunk and the bronchi and bronchioles being the branches. The medical term for all the air tubes is 'the respiratory tract'.