For Ages 12-14
The heart must ceaselessly move blood around your body to keep you alive. It pushes that blood through a system of blood vessels. Those vessels branch out to carry blood all over your body, making oxygen, nutrients, water, and dissolved electrolytes available to every cell in your body. They also carry away waste materials for disposal or recycling. The heart, with all its associated vessels, is called the cardiovascular system. This name — cardiovascular — is one of those anatomy word puzzles: cardio- means “heart” and vascular means “vessels.”