In order to accomplish your goals in life you must do a lot of work. Not work in the economic sense, but work in the scientific sense, which means to transfer energy from one form to another by application of a force over some distance. The purpose of this work includes, but is not limited to; the regulation of temperature, maintaining chemical concentrations, blood circulation, breathing, nerve impulse production, physical movements, and manipulation of environmental objects. A side-effect of doing all this work is the production of thermal energy which you release to your environment as heat. The combination of doing work and generating heat depletes your internal energy reserves, requiring you to take in more chemical energy (food). The purpose of the human body is to facilitate the body’s energy pathway, (energy input, energy storage, work output, and heat release), in order to maintain the conditions necessary for life and allow you to accomplish those things which are important to you.

The basic energetic functions of the human body. This book will discuss the physics concepts behind this diagram, in addition to many others. The diagram will acquire more detail as we go along, eventually morphing into the complete concept map shown in the next Chapter.