| A | B |
|---|
| Trachea | Windpipe |
| Diaphragm | Muscle that aids in breathing |
| Respiration | Unconscious exchange of air at the lungs |
| Epiglottis | Flap of cartilage that covers the larynx |
| Carbon dioxide | Exhaled from lungs as waste |
| Exhalation | Breathing out |
| Alveoli | Tiny air sacs in the lungs |
| upper respiratory tract | nose, pharynx, larynx |
| lower respiratory tract | trachea, bronchi, bronchioles, alveoli |
| functions of the nose | air is filtered, warmed, and humidified |
| nostrils | openings in nose through which air enters |
| pharynx | passageway for air and food |
| larynx | "voicebox" - produces sound |
| epiglottis | flap of cartilage that covers trachea during swallowing |
| trachea | "windpipe" that brings air to lungs |
| bronchi | left and right branches of the trachea |
| bronchioles | very small tubes that branch off secondary bronchi |
| alveoli | air sacs at the ends of secondary bronchi |
| function of alveoli | gas exchange |
| spongy tissue of lungs | composed of clusters of alveoli |
| external respiration | exchange of gases between lungs and bloodstream |
| internal respiration | exchange of gases between bloodstream and body cells |
| inspiration | inhaling air into lungs |
| expiration | exhaling air from lungs |
| inspiratory muscles | diaphragm and external intercostals |
| expiratory muscles | abdominal muscles and internal intercostals |
