During inhalation the diaphragm contracts thus moving down and the external intercostal muscles contract moving the rib cage up and outwards. Meanwhile, the diaphragm contracts and flattens. This increases the volume of the thoracic cavity therefore decreasing the pressure inside the lungs. This causes air to rush into the lungs.
The main purpose of inhalation is to provide the body with oxygen required for aerobic respiration.
- ↑ William J. Germann and Cindy L. Stanfield, Principles of Human Physiology (2012) Page 528