a: Gross anatomy of lung and thorax. b: Microscopic anatomy of bronchial wall. C: View of terminal airway and alveoli. d: Alveolar structure.

Clean air then enters the two bronchi, one bronchus going to each lung. The bronchi in the lungs split into smaller and smaller tubes called bronchioles. These end in microscopic air sacs called ...

Bronchus The trachea splits into a left and right bronchus (plural: bronchi), each leads to a lung. Bronchiole Each bronchus splits again and again into thousands of smaller tubes called ...