| A | B |
|---|
| respiratory system | the group of organs that take oxygen from the air and remove carbon dioxide from the body |
| mucus | a sticky liquid produced by the linings of the nose and other body parts that open to the outside |
| trachea | the tube that leads from the throat toward the lungs, also called the windpipe |
| inhale | to breathe in |
| bronchial tube | one of the pair of tubes that branch off from the trachea and go into the lungs |
| air sac | one of the tiny pouches in the lungs in which the exchange of oxygen and carbon dioxide takes place |
| exhale | to breathe out |
| diaphragm | the large muscle below the lungs that helps you breathe |
| capillary | a tiny blood vessel with thin walls through which oxygen, nutrients, and wastes pass |
| excretory system | the group of organs that get rid of cell wastes |
| kidney | one of the pair of organs of the excretoty system that filter cell wastes from blood |
| urine | a liquid formed in teh kidneys consisting of nitrogen wastes, some salts, and extra water |
| urinary bladder | a muscular, baglike organ that stores urine until it leaves the body |
