✅Functions Of The Respiratory System In The Horse Gas exchange is the major function of the lung, which ensures the transport of oxygen (O2) from air into blood and of carbon dioxide (CO2) in the reverse direction. ✅ Ribs and Respiratory Mechanics The ribs provide the structure for the chest cavity and, with the intercostal muscles and the diaphragm, facilitate the mechanics of breathing. Check in at https://www.winnhorses.org/horsemanship-clinics to see where you can catch up to Wendy . ✅Blood