Oxygen diffuses through the alveolar and capillary walls to the bloodstream, binding to hemoglobin in purple blood cells. Simultaneously, carbon dioxide, a byproduct of cellular metabolism, diffuses in the blood in to the alveoli to become exhaled. b(one) : the circulation and exchange of gases during the lungs or gills https://remingtonxlaoc.bloggerchest.com/37629602/getting-my-ventilation-ductwork-to-work