Breathing is the process that brings oxygen in the air into your lungs and moves oxygen and through your body. Our lungs remove the oxygen and pass it through our bloodstream, where it's carried off to the tissues and organs that allow us to walk, talk, and move.
Our lungs also take carbon dioxide from our blood and release it into the air when we breathe out.
The SINUSES are hollow spaces in the bones of your head. Small openings connect them to the nasal cavity. The sinuses help to regulate the temperature and humidity of the air your breathe in, as well as to lighten the bone structure of the head and to give tone to your voice.
The NASAL CAVITY (nose) is the best entrance for outside air into your respiratory system. The hairs that line the inside wall are part of the air-cleansing system.
Air can also enters through your ORAL CAVITY (mouth), especially if you have a mouth-breathing habit or your nasal passages may be temporarily blocked.