How much does our skeleton weigh? What does the brain do in a dream? Why is the blood red and the snot green? What happens if you don't brush your teeth for a month? Why doesn't a person have a tail? Why do some people have curly hair, while others have straight hair? These and other children's questions are answered by the scientist, therapist, candidate of medical sciences Maxim Kaltygin. The book tells in detail, but without boring academicism, about the main organs and systems of our body, about the processes that go on in our body while we are busy with everyday affairs. The child learns not only about the structure of the body at the macro and micro levels, but also about the mechanisms of memory and speech, about the classical proportions of a person and the medicine of the future. At the end of the book - tasks and a story about body parts that we see in the mirror, but whose names we do not know.