The arteries carry blood from the heart to places in the body that need oxygen. The veins carry blood to the heart. They carry blood that needs oxygen. The heart then pumps the blood to the lungs. That is where the blood gets its oxygen. When the blood gets the oxygen it needs it gets passed through blood vessels called capillaries. Capillaries are one cell thick. Capillaries are thin so the blood can seep through. Alveoli, in the lungs are air sacs. Capillaries cover them and absorb oxygen into the blood. That is how oxygen gets to the body. How does the blood get rid of waste? See our pages about the kidneys and the liver. |
