Some scholars thought directly about health and some thought about other related factors. Therefore, innumerable causes came to be related to the question of health. Lot of thinking about the body has been done over thousands of years. Modern physiologists have tried to reveal the subtlest mysteries of the body.
If we go back to the past, we find that the acharayas dealing with Yoga thought a great deal about the body. Yoga came to acquire an independent anatomy. Yoga has its own physiology. The metaphysics mulled over the body and they are successful in forming their own physiology.
Innumerable ideas and concepts about the body have come into vogue.