Breathing

Process of moving air in and out of the lungs

Breathing (respiring or ventilating) is the rhythmic process of inhaling air into the lungs providing oxygen, and exhaling the air removing carbon dioxide, in the gas exchange process. All aerobic organisms require oxygen for cellular respiration, which extracts energy from food and produces carbon dioxide as a waste product. External respiration (breathing) brings air to the alveoli where gases move by diffusion; the circulatory system then transports oxygen and carbon dioxide between the lungs and the tissues.

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