Your Vascular System
Your vascular system is made up of vessels that carry your blood throughout your body. Arteries carry oxygen-rich blood away from your heart. Veins carry oxygen-poor blood back to your heart. Your blood leaves the left side of the heart and is pumped out to the rest of your body.
The aorta is the main artery from your heart. As your blood travels throughout your body, it enters smaller and smaller blood vessels, reaching every cell, dropping off nutrients and picking up waste products and carbon dioxide.
Your blood then starts the trip back in your veins, entering larger and larger ones as it goes, passing through your kidneys and liver on the way to drop off waste products. The blood eventually comes back to the right side of your heart to start all over again.