Exhalation This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Exhalation".
Exhalation (or expiration) is the movement of air out of the bronchial tubes, through the airways, to the external environment during breathing.
Exhaled air is rich in carbon dioxide, a waste product of cellular respiration during the production of ATP.
Exhalation has a complementary relationship to inhalation; the cycling between these two efforts define respiration.
