Fourth Grade
Worksheets
Your Circulatory System
Your circulatory (say: SIR-kyuh-luh-tohr-ee) system has three parts. The main part is your heart. Your blood is another part. Your blood vessels are the third part.
Your circulatory system works like a delivery truck. It takes blood to all parts of your body. Your body is made up of tiny cells. The blood carries things to your cells that they need. Then your blood picks up the waste products from the cells. These are the things that your cells don't need.
Your heart is an organ inside your chest. It is about the same size and shape as your fist. It is a muscle. The heart's job is to pump your blood. The blood's job is to move the things your body needs. The blood goes to each little cell that makes up your body.
