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.
There are two types of physiological respiration in animals: internal respiration, and external respiration. Internal respiration is the process of cells in the body exchanging gases, while external respiration is the process of respiration that actually takes place within respiratory organs like the lungs.