Air, the most common and only natural breathing gas, is primarily used in breathing. However, it's a mixture of several gases, with oxygen being the vital component for respiration.
The Key Respiratory Gases
While air is the overall answer, it's crucial to understand that several gases play important roles in the respiratory process:
-
Oxygen (O₂): This is the primary gas used by our bodies for aerobic respiration, the process of converting food into energy. As noted in the reference, "[t]hree vital respiratory gases-oxygen (O(2)), nitric oxide (NO), and carbon dioxide (CO(2))-intersect at the level of the human red blood cell (RBC)." https://pubmed.ncbi.nlm.nih.gov/21496039/
-
Carbon Dioxide (CO₂): This gas is a waste product of respiration, exhaled from the lungs. It's also involved in regulating blood pH.
-
Nitric Oxide (NO): Though present in smaller amounts, nitric oxide plays a crucial role in regulating blood vessel dilation and other functions within the respiratory system. As stated in the reference, "[t]hree vital respiratory gases-oxygen (O(2)), nitric oxide (NO), and carbon dioxide (CO(2))-intersect at the level of the human red blood cell (RBC)." https://pubmed.ncbi.nlm.nih.gov/21496039/
Other Gases and Breathing
Other gases are sometimes used in specific medical contexts, such as:
- Hyperbaric oxygen therapy: Uses pure oxygen at increased pressure to treat various medical conditions. https://www.mayoclinic.org/tests-procedures/hyperbaric-oxygen-therapy/about/pac-20394380
- Nitrous oxide (N₂O): Used as an anesthetic in medical settings, but it is not a gas used for routine breathing. https://www.ncbi.nlm.nih.gov/books/NBK532922/
In summary, while the question "Which gas is used in breathing?" can be answered simply as "air", a deeper understanding requires acknowledging the crucial roles of oxygen, carbon dioxide, and nitric oxide within the respiratory system. A breathing gas, as defined by Wikipedia, is "a mixture of gaseous chemical elements and compounds used for respiration." https://en.wikipedia.org/wiki/Breathing_gas
