If you want to find the answer to these and many, many other questions, this is the book for you! Absorbing texts and over 250 pictures tell you everything you need to know about your body. Here you will find out how the brain functions and how the heart works. You will learn how the blood circulates and the muscles move, why we need sleep and how our immune system fights off illnesses. And do you know why we have two nostrils? The answers are inside!