With 6 trillion cells, 206 bones, and 600 muscles, the human body is an amazing living mechanism that is in intense and constant activity.

For all curious readers, the Knowledge Guides open the door to a world of complex and captivating phenomena.

Accurate, detailed visual information is all defined in lay language to make it readily accessible to the non-expert. Definitions to scientific terms are given either in the explanation itself, or in the comprehensive glossary.