How do we not use any air in the respiratory system?

Tiny hairs called cilia (pronounced: SIL-ee-uh) protect the nasal passageways and other parts of the respiratory tract, filtering out dust and other particles that enter the nose with the breathed air. read more

Clearing the Air. The respiratory system has built-in methods to prevent harmful substances in the air from entering the lungs. Hairs in your nose help filter out large particles. Microscopic hairs, called cilia, are found along your air passages and move in a sweeping motion to keep the air passages clean. read more

Your lungs and respiratory system automatically perform this vital process, called gas exchange. In addition to gas exchange, your respiratory system performs other roles important to breathing. These include: Bringing air to the proper body temperature and moisturizing it to the right humidity level. Protecting your body from harmful substances. read more

The lungs and respiratory system allow oxygen in the air to be taken into the body, while also enabling the body to get rid of carbon dioxide in the air breathed out. Respiration is the term for the exchange of oxygen from the environment for carbon dioxide from the body's cells. read more