If you do not have Shockwave, click here to download it. Click here for more information. As you read, check your drawing to see that it fits the description. Also, add information that is new to you. Find out about the network of tubes, or blood vessels, through which blood flows .
Arteries carry blood away from the heart.
Veins carry blood back to the heart. Arteries branch into smaller and smaller blood vessels as they get farther from the heart. As they get closer to cells, arteries become extremely small and are called capillaries. At the cells, capillaries join together and are known as veins. Open the link and try to figure out how the different types of blood vessels keep blood containing oxygen separate from blood containing carbon dioxide.