1. Introduction: The work your body never stops doing
Right now you are sitting still and reading. You feel like you are "doing nothing." But inside you, nothing has stopped. Your heart is pumping. Your lungs are pulling in air. In every cell, food is being burned for energy and waste is being cleared out.
That non-stop maintenance work is what we call life processes — the basic jobs a living body must keep doing every second just to stay alive.