Testing Your Knowledge

1. What are the two major functions of external respiration?

2. What is the connection between external respiration and aerobic, cellular respiration?

3. How does an animal’s size, activity level, and environment influence the structure and function of its respiratory system?

4. Trace the path of an oxygen molecule from a person’s nose to a red blood cell.

5. To what structures in the human respiratory system do an insect’s trachea and trachioles correspond?

6. How is air cleaned before it reaches the lungs?

7. Describe inspiration. Which muscles are active in the process?

8. How does the body transport oxygen to cells?

9. What mechanisms direct more oxygen to metabolically active cells?

10. How does the respiratory system transport most CO2? In what other ways is CO2 transported?

11. How does the brain establish breathing rhythm?

12. What chemical change in the blood is most important in altering breathing rate?