BREATHING PROCESS

The breathing process (breathing) is divided into two distinct phases: inspiration (inhalation) and expiration (exhalation). During inspiration, the diaphragm contracts and pulls down while the muscles between the ribs contract and pull up. The size of the thoracic cavity becomes larger and the pressure inside becomes smaller. The air enters and fills the lungs. During expiration, the diaphragm relaxes and the volume of the thoracic cavity is smaller, while the pressure inside it becomes larger. The air is expelled.