Blood is a very important tissue. Blood carries food, waste, oxygen, and carbon dioxide to and from all the cells in the body.

The heart applies pressure^* which pushes blood through tubes called blood vessels. As it travels through these blood vessels it also exchanges heat with body tissues. This process keeps our bodies at a constant^* temperature. Blood contains two main types of blood cells.

There are 4 main blood types.

Food that helps to keep our blood healthy are rich in iron. Children and women should be especially careful to eat plenty of foods that are high in iron to maintain healthy blood.