Four primary regions are the brainstem, the cerebellum, the cerebrum, and the cerebral cortex. Each brain region is responsible for a variety of functions, and injury to any of these regions impairs specific functions.
Cellular respiration is a pathway that organisms use to generate energy. Oxygen is required and is used to break down nutrients, like glucose sugar. The nutrients are broken down to generate ATP (energy) and carbon dioxide and water (waste). Organisms from all kingdoms of life can use cellular respiration including bacteria, archaea, plants, protists, animals, and fungi.
All cells from living organisms undergo cellular respiration. Respiration occurs in the mitochondria of  eukaryotic cells and in the cytoplasm of prokaryotic cells. A cell under goes two types of respiration 1st aerobic and 2nd anaerobic respiration. In 1st one cell need or cell use oxeygen, and 2nd one in which cell respire with out oxygen.