Start of End of capillary capillary Perfusion limfrCorme attheed Nboyu Lnu cParosij eHcetlletatifrooCmr ethatee dN obuyn L uPcroajse cHtellenCfrreoamt etdh eb yN oLuucn aPs r Hojeellcet frCofCmrrr eoethaemtae tNd eo tbuhdyn e LbPu rcNyoa jeosLc Huutenclle aPsr oHjeelclet froCmr ethatee dN obuyn L uPcroajse cHtelle Cfrreoamt etdh eb yN oLuucn aPsr Hojeellcet Alveolar N O 2 O (normal) 2 e r u s O (Abnormal) s 2 e r p Venous PO2 l a i t r a P Diffusion limitation CO 0 0.25 0.50 0.75 Time in capillary (sec)