- May 18, 2019-

The airbag is a kind of compressed air or water medium filled in a flexible rubber capsule; the elasticity is achieved by the compressibility of air and the fluidity of water. Birds have 9 airbags. It has the function of assisting breathing, reducing body density, reducing friction and heat dissipation between organs. The posterior air is connected to the end of the middle bronchus, and the front airbag is connected to the abdominal bronchi.