1. Patients with chronic bronchitis have excessive mucus production and general inflammation of the entire respiratory tract. The mucus narrows the airways and makes breathing difficult. Explain what does narrowing of the airways do to resistance of the airways to air flow?

2. Why do people with chronic bronchitis have a higher than normal rate of respiratory infections?

3. Compare the possible consequences of breathing too rapidly with the possible consequences of breathing too slowly.

4. If alveolar ventilation increases, what do you predict will happen to arterial PO2? To arterial PCO2?To venous PO2?To venous PCO2?  Explain.

5. When the pulmonary blood flow to a lung is blocked, as by embolus, the region may survive on its bronchial flow. Why does the affected lung region continue to expire CO2 but not to take up significant O2?

6. What congenital defects underlie left-to-right shunts that increase PO2 first in the 1) right atrium, 2) right ventricle, 3) pulmonary artery?

7. Explain why normal people can function very effectively even when their systemic arterial PO2 is only 40 mm Hg (e.g., hypoxic hypoxia of high altitude), which is the same tension found in normal mixed blood.

8. Discuss whether edema-filled alveoli constitute a diffusion defect (the barrier is too thick) or a ventilation/perfusion problem (the alveoli are full of liquid). If the alveolar-arterial oxygen partial pressure difference was found to be 300 mm Hg while the subject was breathing oxygen for 10 minutes, what would you conclude about the mechanism of the arterial hypoxemia?

9. Describe how the oxygen supply to skeletal muscles is regulated at rest and during vigorous exercise.

10. Various drugs can antagonize the carbonic anhydrase in circulating red blood cells. What changes might you expect in the blood or in the body if you studied a person before and after such a substance had been taken? Distinguish between early (non-steady-state) events and steady-state events.

11. Severe hemorrhage increases peripheral vasoconstriction and heart rate. Why does it cause rapid breathing?

12. Why does left ventricular failure or mitral valve dysfunction cause elevated pulmonary blood pressure?

13. What would happen to the following in a person suffering from an acute asthma attack (bronchoconstriction)?