Bronchi
1. The two branching tube of trachea are called bronchi.
2. There are two bronchi
3. The walls of bronchi are not richly supplied with blood capillaries.
Alveoli
1. The out growths of microscopic air sacs are called alveoli.
2. There are millions of alveolar sacs.
3. The walls of the bronchioles are richly supplied with blood capillaries.
