The process by which gas is drawn into the lungs through the trachea (see respiratory movement). In mammals the rib cage is raised by contraction of the external intercostal muscles and the muscles of the diaphragm. These actions enlarge the thorax, so that pressure in the lung cavity is reduced below atmospheric pressure, which causes an influx of air until the pressures are equalized. Compare expiration.
Subjects: Sports and Exercise Medicine — Biological Sciences.