The overall purpose of this preparatory course textbook is to help students familiarize with some terms and some basic concepts they will find later in the Human Anatomy and Physiology I course.The organization and functioning of the human organism generally is discussed in terms of different levels of increasing complexity, from the smallest building blocks to the entire body. This Anatomy and Physiology preparatory course covers the foundations on the chemical level, and a basic introduction to cellular level, organ level, and organ system levels. There is also an introduction to homeostasis at the beginning.