Across
- 2. tiny hair in your respiratory system
- 3. this regulate temperature and humidity of the air
- 5. the lungs fill in?
- 8. tube that delivers air from your mouth and nose to the trachea
- 10. small branches that lead to the alveoli
- 11. these are classified millions of microscopic air sacs called -------?
- 12. external extension of fishes are called
Down
- 1. also called as voice box
- 4. found on land and transport oxygen and carbon dioxide in their skin
- 6. used in photosynthesis in exchange of Oxygen
- 7. a major organ that expands and contracts
- 9. Gas pass through pores called ---- in the epidermis