Covers the levels of organization of the human body. We have moved all content for this concept to for better organization. Please update your bookmarks accordingly. 1. Explain the difference between anatomy and physiology. Anatomy is the study of the structures of the human body and physiology is the study of the function of the body's parts. 2. Please organize the following structures in order from smallest to largest: system, tissue, organ, and cell. Cell, Tissue, Organ, System. 3.