Anatomy is the study of what the parts are. Babies just learning their first words are usually avid students of anatomy. "Where's your nose?" "Show me your eyes."
Physiology is the study of what the parts are for. Why do we have kneecaps? What is your pancreas for? This has not always been obvious. The ancient Greeks thought that the spleen produced anger. The Egyptians believed the brain to serve no purpose whatsoever.
It's one thing to know that you are part of the body of Christ. It is another thing entirely to know what purpose you serve in the body.
