What is blood for kids?
Blood is needed to keep us alive. It brings oxygen and nutrients to all the parts of the body so they can keep working. Blood carries carbon dioxide and other waste materials to the lungs, kidneys, and digestive system to be removed from the body. Blood also fights infections, and carries hormones around the body. Red blood cells deliver oxygen to tissues and organs, such as muscle, the liver and the brain. Blood also contains white blood cells. These help the body fight disease.