This edition: The Respiratory System
Cells in our bodies need oxygen for the production of ATP, and the by-product of that energy production—carbon dioxide—must be removed from the body. While the network of blood vessels in the cardiovascular system transports these gases, oxygen must continuously be replenished as our cells use it. Likewise, carbon dioxide must be constantly eliminated to help maintain homeostasis. This exchange of gases is the primary role of the respiratory system, but not the only role.