The respiratory system facilitates gas exchange between the body and environment. It involves the intake of oxygen and exhalation of carbon dioxide. Large animals developed respiratory surfaces like lungs and gills to efficiently exchange gases through diffusion. The human respiratory system includes the nose, pharynx, larynx, trachea, bronchi, bronchioles and alveoli which deliver air to the lungs for gas exchange via diffusion between alveoli and capillaries before exhalation. Diseases can impact the respiratory system by affecting airway condition or gas exchange.

1. Respiratory System (Human And Animal)

4. Gas exchange systems in several animals