Respiratory System in Mammals

The mammalian heart is more compartmentalized than reptile lungs.
Bronchi, bronchioles, alveoli.
In each lung of a human, there are about 150.000.000 alveoli.
The alveoli for gas exchangePharinx, Trachea, larynx
Endothelial cell layer in respiratory passageway.
Mucus covering the respiratory cell surface.
Ciliated cells
Nose, nasal cavity and its function for humidification of airUpper tract
Nose, pharynx and associated structures
Lower tract
Larynx, trachea, bronchi, lungs