If a molecule of CO 2 released into the blood in your RIGHT toe eventually exits your nose, it must pass through all the following EXCEPT: Pulmonary vein Right atrium Right ventricle Pulmonary artery It travels through all Capillaries are better for material exchange because compared to arteries and veins, capillaries.. I. have blood moving slower through them II. have blood move faster through them III. have a lower SA:V IV. have a higher SA:V I and IV II and III How does the shape of red blood cells help with transporting oxygen? The concave shape decreases SA:V for better oxygen exchange The concave shape increases SA:V for better oxygen exchange The disc shape WITHOUT being concave increases SA:V to increase oxygen exchange The disc shape WITHOUT being concave increases SA:V to decrease oxygen exchange.