Osmosis video - Breathing cycle and regulation

The respiratory cycle is the process of inhaling and exhaling air. The main purpose of the respiratory cycle is to bring fresh oxygen into the body and to expel carbon dioxide. Breathing is made possible thanks to a muscle called the diaphragm. When the diaphragm contracts, it pulls downward, which causes the chest cavity to expand. This expansion creates a vacuum that draws in air from outside the body, this is called inhalation. When the diaphragm relaxes, it pushes upward, which causes the chest cavity to contract and expels air from within the body, this is referred to as exhalation.