| A | B |
|---|
| Brain | the body's control center |
| Spinal cord | a bundle of neurons running within the spine |
| Neurons | cells which carry electrical signals throughout the body |
| Reflex | a quick action before the brain knows |
| Trachea | the tube air passes through in the neck |
| Bronchial tubes | air passage ways inside the lungs |
| Alveoli | small lung sacs where air enters the blood |
| Diaphragm | a muscle which controls breathing |
| Inhale | to breath in |
| Exhale | to breath out |
