The primary function of the lungs is to facilitate the exchange of gases between the body and the atmosphere. They play a vital role in the process of respiration, where oxygen from inhaled air is absorbed into the bloodstream and carbon dioxide, a waste product of metabolism, is expelled from the body during exhalation. This gas exchange occurs in tiny air sacs called alveoli, where oxygen diffuses into the blood while carbon dioxide is released from the blood into the air sacs. Proper lung function is essential for sustaining life and supporting energy production in cells.