What makes the heart beat faster or slower? How do tightrope walkers keep their balance? Why does spinning fast cause dizziness? Explore the mysteries and the workings of the human body through this fascinating collection of ideas, projects, and activities. Have fun while you learn about everything from the body's basic building blocks to how the brain receives messages from other parts of the body. Make a model of a human cell that you can eat for dessert. Make a working model of a human lung from a soda bottle, a balloon, and a garbage bag. Through these and other activities, you'll find...