The respiratory system brings oxygen into the body and removes carbon dioxide. Air enters through the nose and passes through the pharynx, larynx, trachea, and bronchi before reaching the lungs. In the lungs, the bronchi divide into smaller bronchioles containing alveoli where oxygen passes from the air into the blood and carbon dioxide is released from the blood and expelled from the body.

1. THE RESPIRATORY SYSTEM We need oxygen to live.

2. We breathe to obtain oxygen from the air.

3. This function is carried out by the respiratory system.