Why do organs in a multicellular organism work in concert?

The work of the whole organism is supported by the central nervous system, it is she who sends signals to all cells and organs. Thanks to the central nervous system, the body can continue to work during sleep. Thus, you do not have to worry that during sleep they will stop working, for example, the lungs and the whole body will suffocate. Each organ has a specific function and role in the body, like gears in a clock, they ensure the operation of the entire system, and when one organ becomes unusable, the whole body suffers.