Introduction To Anatomy and Physiology

Anatomy is the structure and relationship of the body and its parts. Anatomy is studied at two levels: gross and microscopic. Those structures studied at the gross level are large and easily observable, whereas those at the microscopic level cannot be seen with the naked eye, but-as the name suggests-needs a microscope. 
Physiology is the study of how the body parts work and carry-out life-sustaining activities. The structure always determines the function. This is called the Principle of Complementarity.