BCS0025 - Anatomy and Physiology: The Respiratory SystemEvery cell in our body needs oxygen: without it we would die within minutes. Every cell in our body must also rid itself of carbon dioxide. As we breathe- or respire - we obtain oxygen by inhaling. When we exhale we release carbondioxide.
Like other bodily functions such as heartbeat and blood pressure, breathing goes on without our conscious attention - for example, when we are asleep. But we can also control our breathing if we wish: during exercise or when swimming, and of course when we talk or sing. The organs that make breathing possible form the respiration system. | 
