RT Book, Section A1 Klocke, Robert A. A1 Shifren, Adrian A2 Grippi, Michael A. A2 Antin-Ozerkis, Danielle E. A2 Dela Cruz, Charles S. A2 Kotloff, Robert M. A2 Kotton, Camille Nelson A2 Pack, Allan I. SR Print(0) ID 1194946592 T1 Diffusion, Chemical Reactions, and Diffusing Capacity T2 Fishman’s Pulmonary Diseases and Disorders, 6e YR 2023 FD 2023 PB McGraw-Hill Education PP New York, NY SN 9781260473988 LK accessmedicine.mhmedical.com/content.aspx?aid=1194946592 RD 2024/03/29 AB Uptake of oxygen and excretion of carbon dioxide require rapid, efficient exchange in the lung. The quantities of exchanged gases are staggering. For example, an 1800-calorie diet requires absorption of 375 L of oxygen per day, as well as excretion of a slightly smaller volume of carbon dioxide. Because blood remains in the pulmonary capillary bed for a limited time, the process of exchange must be accomplished in less than 0.75 s at rest and 0.5 s during exercise. This rapid, high-volume exchange occurs efficiently despite numerous interacting processes of diffusion and chemical reaction that occur in the lung. The rates of these processes are not only affected by intrinsic characteristics of blood but also determined by a host of other factors, including inspired oxygen fraction, alveolar gas tensions, cardiac output, and metabolic activity. The ease of exchange of respiratory gases belies the complexity of the overall process.