1. Describe and differentiate between external and internal respiration. 2. Describe the mechanisms involved in inspiration and expiration. 3. What is a spirometer? Describe and define the lung volumes measured using spirometry. 4. Explain the concept of partial pressures of respiratory gases—oxygen, carbon dioxide, and nitrogen. What is the role of gas partial pressures in pulmonary diffusion? 5. Where in the lung does the exchange of gases with the blood occur? Describe the role of the respiratory membrane. 6. How are oxygen and carbon dioxide transported in the blood? 7. Describe the oxygen cascade from dry ambient air to the tissues and into the venous circulation. Provide appropriate values for the various partial pressures of oxygen at each level. 8. How is oxygen unloaded from the arterial blood to the muscle and carbon dioxide removed from the muscle into the venous blood? 9. What is meant by the arterial–mixed venous oxygen difference? How and why does this change from resting conditions to exercise conditions? 10. Describe how pulmonary ventilation is regulated. What are the chemical stimuli that control the depth and rate of breathing? How do they control respiration during exercise?