The bodily process of inhalation and exhalation; the process of taking in oxygen from inhaled air and releasing carbon dioxide by exhalation.
The metabolic processes whereby certain organisms obtain energy from organic molecules; processes that take place in the cells and tissues during which energy is released and carbon dioxide is produced and absorbed by the blood to be transported to the lungs.
See moreMovement of oxygen from the outside air to the cells within tissues, and the transport of carbon dioxide in the opposite direction.