>>13415657luckily for you there is a whole subject on it. It falls in the very esoteric domain of "biology". There you can learn how cells operate, how they signal to other cells and how they differentiate to form complex tissues and organs. If you want to get more advanced there are courses in biology of cancer where you will learn how cells can stop working correctly and what forces keep them working for the whole.
If you look at biology through a evolutionary perspective you'll learn how organisms increase in complexity which will teach you a lot about your own body and how it works.
Needless to say you got a fucktonne of reading and learning to realize how this works.
If you want a philosophical answer read about emergentism, although that won't teach you about the actual mechanisms the body does employ.
