Across
- 3. the part of the brain that sends messages to regulate the working rate of the lungs
- 6. a life-threatening colorless and odorless gas
- 7. a condition that causes the bronchioles to constrict
- 10. an iron-rich protein that oxygen binds to
- 13. movement of molecules from an area of high to low concentration
- 14. a lung disorder, which destroys alveoli over time
- 15. a disease causing the lungs to produce thick, sticky mucus
Down
- 1. air sacs where gas exchange take place
- 2. the organ system responsible for gas exchange
- 4. the best biology teacher
- 5. the type of feedback loop determining the working rate of the lungs
- 8. the leading cause of respiratory diseases
- 9. the smallest of the three types of blood vessels
- 11. a gas molecule essential for human survival
- 12. the organ where alveoli reside