How does the Air Travel Through the Respiratory System Respiratory system in humans Humans, like many other land animals with backbones, breathe in oxygen-rich air and breathe out carbon dioxide-rich air with the help of lungs. Lungs are present inside our chest (also called the thorax). They are protected by the rib cage. The ribs also support the lungs and help to pump air … [Read more...] about How does the Air Travel Through the Respiratory System