What gases are added to inhaled air and then exhaled?

The primary gases added to inhaled air and then exhaled are carbon dioxide and water vapor. During the process of cellular respiration, oxygen from inhaled air is used by the body's cells to generate energy. As a byproduct of this process, carbon dioxide is produced and transported by the bloodstream to the lungs. The lungs then expel the carbon dioxide into the exhaled air. Additionally, water vapor is released into the exhaled air as a result of the body's natural processes, including cellular respiration and evaporation from the respiratory tract.