The Circulatory System—the Body's Moving company

The Circulatory System—the Body's Moving  company

The circulatory system is an organ system that includes the heart, the blood
vessels, and the blood itself. It has three functions:
• to transport materials (i.e., nutrients and oxygen) and cells from one place to
another
• to defend the body against invasion by harmful organisms by taking white
blood cells to an area of injury or infection
• to maintain a constant body temperature
Your body has a closed network of blood vessels—hollow tubes—that move blood
and nutrients. A pumping organ—the heart—pushes blood through this network of
vessels.