Which system, besides the respiratory system, also uses oxygen and carbon dioxide?

The circulatory system plays a crucial role in the transportation of oxygen and carbon dioxide throughout the body. It works closely with the respiratory system, where oxygen is taken in through the lungs and transferred to the bloodstream. The heart pumps this oxygen-rich blood to various tissues and organs.

Additionally, carbon dioxide, a waste product of aerobic metabolism, is transported back to the lungs via the bloodstream, where it is expelled from the body when we exhale. This exchange of gases – oxygen being delivered to cells for energy production and carbon dioxide being removed – is vital for maintaining cellular respiration and overall metabolic processes.

This interdependence means that the circulatory system is integral in managing the levels of these gases in the body, making it the correct choice in the context of this question.