| A | B |
|---|
| Pharynx | throat, carries air into respiratory tract and food to the digestive system |
| Larynx | voice box, contains vocal cords |
| Epiglottis | covers larynx upon swallowing to help prevent food from entering the respiratory system |
| Trachea | windpipe, conducts air to lungs |
| Bronchi | branches of trachea that enter lungs and then subdivide |
| Bronchioles | smallest subdivisions of the bronchi |
| Lungs | organs of gas exchange |
| Alveoli | tiny sacs where gases are exchanged |
| Surfactant | reduces surface tension in alveoli to ease expansion of the lungs |
| Nasal Cavities | filter, warm, and moisten air |
| Diaphragm | muscle that separates thoracic and abdominal cavities |
| Pleura | membrane that encloses the lung |
| Mediastinum | space between lungs, contains the heart |
