the exchange of oxygen and carbon dioxide between air in the alveoli and blood in the pulmonary capillaries is called
Confidence votes 38. The Diffusion is the exchange of oxygen (O2) and carbon dioxide (CO2) between the alveoli and the blood. So blood that is pumping through the capillaries in the lungs has a low concentration of O2 and a high concentration of CO2, in the alveoli it is high concentration O2 low concentration CO2. Therefore the 2 gases exchange across the alveoli membrane by diffusion trying to establish a concentration gradient.