Beachey: Respiratory Care Anatomy and Physiology, 2nd Edition

Answers to Concept Questions

Chapter 9: Carbon Dioxide Equilibrium and Transport

9-1	Removing carbon dioxide molecules from the blood “pulls” the hydration reaction to the left, causing blood hydrogen and bicarbonate ions to react to form carbonic acid and ultimately more carbon dioxide. As long as the body continues to remove CO2 molecules, this process continues, and blood H+ concentration falls.

9-2	Inadequate ventilation means the lungs do not remove carbon dioxide rapidly enough to keep up with its rate of production by the tissue cells. Consequently, blood CO2 builds up and PCO2 rises. This drives the hydration reaction to the right, generating the volatile acid, H2CO3.

9-3	Normally, ventilation keeps pace with the increased carbon dioxide production of exercise, maintaining a constant blood PCO2. Thus the blood volatile acid (H2CO3) content remains constant.

9-4	If carbonic anhydrase were suddenly removed from the blood, the hydration reaction’s speed in the erythrocyte would slow greatly. As a result, carbon dioxide diffusion rate into the erythrocyte would slow and plasma PCO2 would rise.