Question

pre - video question: what gases are exchanged in the respiratory system?
select all that apply, then click submit below
carbon dioxide
nitrogen
carbon monoxide
oxygen
helium

Explanation:

The respiratory system's main function is gas exchange. Oxygen ($O_2$) is taken in from the air we breathe. This oxygen is then transported to cells throughout the body for cellular respiration. At the same time, carbon dioxide ($CO_2$), a waste product of cellular respiration, is transported back to the lungs and exhaled. Nitrogen is the most abundant gas in the air we breathe (about 78%), but it is not significantly exchanged in the respiratory system as it is mostly inert in the body's normal metabolic processes. Carbon monoxide is a toxic gas. In normal, healthy respiratory function, it is not a gas that is exchanged (except in cases of exposure to carbon - monoxide - containing environments like smoke, but that's a pathological situation, not normal gas exchange). Helium is also not involved in the normal gas - exchange process of the respiratory system.

Answer:

carbon dioxide, oxygen