The human body harbors an incredible range of diversity at not only the physical and creative level but also in the dynamics of the entire cellular system. At adulthood the average human body has almost 10 trillion cells and has over 200 different categories of cells. A few of these types of cells are shown here. We have over 200 bones and thousands upon thousands of fibers which go into making up the various 600 muscles that we depend on not only for movement, but also facial expression and communication. The brain has over 100 billion neurons. The diverse chemistry that our bodies depend on helps to fashion our mood, behavior and health. There are two types of enzyme systems: metabolic and digestive. Additionally the body is composed of glands, hormones, senses, and various immunological responses that all contribute to its well- being and function. About the background image: Confocal light micrograph of cultured endothelial cells. A fluorescent dye has been used to show the cell structure. Endothelial cells are flat and line all of the body’s blood vessels.