Commercial Door Threshold - Width 4 in, Color/ Finish Mill Finish, Material Aluminum, Thickness 1/2 in, Length 145 in Average rating: out of 5 stars, based on reviews Write a review ratings q&a
Capillaries connect the arteries to veins. The arteries deliver the oxygen-rich blood to the capillaries, where the actual exchange of oxygen and carbon dioxide occurs. The capillaries then deliver the waste-rich blood to the veins for transport back to the lungs and heart. Veins carry the blood back to the heart.
Therefore, most veins carry deoxygenated blood and most arteries carry oxygenated blood. However, the pulmonary veins carry oxygen rich blood to the heart, and the pulmonary arteries carry oxygen poor blood to the lungs. So, in short: no they do not carry blood all the time; the pulmonary veins carry oxygenated blood. Source(s): B.S. in Biology. MayDay Â· 6 years ago.