I attached the image related to your concerned question.
In theory, the part of the brain that is responsible for the sleep wake cycle is the hypothalamus; specifically, the ventrolateral preoptic nucleus of the hypothalamus. In the image, the location of the hypothalamus is pointed by the green square.
Zoning laws establish the uses an area of land can be put to. Zoning's basic purpose is to equally divide the municipality into zones which includes residential, commercial and industrial zones. Separating and use of these zones should be reasonably equal.