Your circulatory system a system that carries your blood throughout your body. Your system is basically made up of your veins, arteries, capillaries, and your heart. Of course, your blood has red/white blood cells platelets, and plasma. Your heart is one of the most important organ. As you know, your heart pumps your blood for you. This is why it plays a important role in the circulatory system. Your arteries are the biggest blood vessels. They carry blood with oxygen away from your heart. They are also the reddish lines a that you see in drawings or diagrams. Your capillaries are your smallest blood vessels. Only one blood cell can fit in the opening at a time. Your veins are the second largest blood vessel. They are the blue lines in diagrams and drawings. It also carries the blood back to your heart. Red blood cells carry oxygen. They can increase the surface for gas exchange. You can find a lot of them in your blood. Platelets are white cells that help stop wounds that keep on bleeding. Plasma is a white liquid that flows around your body. What Does This System Work With? The Circulatory system works with the Respiratory system because when we breath in and out oxygen and carbon dioxide, the red blood cells transports these around your body. How Can You Help Protect This System? You can help by not smoking first, because your red blood cells carry your oxygen and carbon dioxide. Also, try to avoid anything that might damage your heart. The End!