Understanding pulmonary gas exchange: ventilation-perfusion relationships.

This essay looks at the historical significance of four APS classic papers that are freely available online: Fenn WO, Rahn H, and OTIS AB. A theoretical study of the composition of the alveolar air at altitude. Am J Physiol 146: 637-653. 1946 (http://ajplegacy.physiology.org/cgi/reprint/146/5/637). Rahn H. A concept of mean alveolar air and the ventilation-bloodflow relationships during pulmonary gas exchange. Am J Physiol 158: 21-30, 1949 (http://ajplegacy.physiology.org/cgi/reprint/158/1/21)). Riley RL. And Cournand A. "Ideal" Alveolar air and the analysis of ventilation-perfusion relationships in the lungs. J Appl Physiol 1: 825-847. 1949 (http://jap.physiology.org/cgi/reprint/1/12/825). Riley RL. And Cournand A. Analysis of factors affecting partial pressures of oxygen and carbon dioxide in gas and blood of lungs: theory. J Appl Physiol 4: 77-101. 1951 (http://jap.physiology.org/cgi/reprint/4/2/77).