Your body's nervous system is fizzing with electricity. It sends messages and instructions to every part of your body and collects information from around you. Your nervous system also controls the hormones that travel in your blood and make chemical changes throughout your body. Sending mesages describes how these amazing systems work. It shows how your body's nerves collect and send information and the part played by your brain. It explains how hormones work and how they control so much of your body's activity. And it outlines what can happen if these complex systems stop working properly." --B.cover.