We take in oxygen and not other gases because oxygen is what is needed to maintain bodily functions. When we inhale, a mix of gases enters the lungs, containing oxygen, nitrogen, carbon(IV)oxide, water vapour and a little noble gases. The air then goes to the lungs together but only the oxygen is diffused into the blood stream. The rest of it is sent back out along with some carbon(IV)oxide that diffuses out. This oxygen is then transported around the body to
1) aid in the break down of food to release energy
2)keep the body oxidized.
These are things that can only be achieved with oxygen and as such, the body takes it in and not the other gases
the organs responsible for the breathing process. Here are the respiratory organs:
1. Nose (Cavum Nasalis)
The nose functions to filter the incoming air and moisturize it. Another function is as a sense of smell detection.
This organ functions to connect the nose to the mouth. With this organ, humans can breathe through the mouth.
3. Throat (Trachea)
Works to connect the nose and mouth to the lungs.
4. Throat Branch (Bronchus)
Continues the task of the throat, connecting the nose to the lungs. There are two bronchuses, namely the right and left.
These are branches that are smaller than the bronchi.
These are air bubbles found at the ends of the bronchioles. This section serves to absorb oxygen entering the lungs.
This is where exchange of incoming oxygen gas and carbon dioxide out through the alveoli.
From a brief description of the function of the respiratory organs above we can see, it turns out that the air that enters our body not only contains oxygen, but other gases also enter. From the nose, pharynx, throat and branches, to the alveoli, oxygen is absorbed; while other gases are released again along with carbon dioxide released from the lungs.