Asking questions and discovering the how and why things work are often the starting points of any scientific inquiry. For children, many initial questions are often centered on the human body. Why do we eat? What organs help me breath? Why don't I have to tell my heart to beat, yet I tell my feet to move? This Lerner Series presents information for intermediate readers to answer these questions and many others about systems of the body. Why is blood red? In Your Circulatory System, the different components of blood are identified. Red blood cells are the most abundant and give blood the red color. White blood cells, platelets, and plasma complete the structure of the blood tissue. As blood moves through the body, nutrients are delivered, wastes are retrieved, infections are fought off, and even clots stop excessive blood flow when injured. What organs are part of the circulatory system? The heart and blood vessels provide its structure.

The four chambers of the heart enable blood to flow throughout the body every minute of every day. The valves open and close providing a one-way path that circulates blood from the heart to the arteries and back to the heart through the veins. Magnified pictures of the aorta connecting to the heart, red and white blood cells, and even capillaries in the eye provide the reader with a point of reference as the inside of the human body is conceptualized. Each book in the series focuses on one system as well as its interaction with other systems to keep the entire organism functioning. The circulatory system takes the nutrients provided by the digestive system and the oxygen provided by the respiratory system to distribute them to cells throughout the body and produce energy. Photographs and diagrams appear as pages are turned to complement and pull the reader into the text. Questions are posed creating an interactive text that will delight! --NSTA.