Most people know that blood is always flowing through our bodies, but many don't know how or why this happens. Readers of this informative volume learn all about the circulatory system-the bodily system that not only carries blood to and from the heart, but also brings oxygen, nutrients, and other materials around the body. Accessible text and eye-catching images support struggling and reluctant readers in learning about this key concept from the upper elementary science curriculum. Provided by publisher.

Includes index.