Through engaging text, readers learn about the human body's respiratory system. Topics include the nose, sinuses, windpipe, bronchial tree, throat, tonsils, larynx, and lungs. Readers learn that snot keeps the lining of the body's airways from drying out and that the diaphragm is the main respiratory muscle. A detailed diagram allows readers to follow a molecule of oxygen through the respiratory system. Kid-friendly text introduces respiratory problems, such as the common cold and influenza, and diseases, such as asthma and lung cancer. Also highlighted are ways to keep the respiratory system in good shape. Full-color photos, medical models, phonetics, glossary, and index enhance the text.