Figure 3.

(a) Calculated values of arterial ${\text{P}}_{O_2}$ (solid lines) and venous ${\text{P}}_{O_2}$ (dashed lines) for simulated conditions of rest, moderate, and maximal exercise as a function of the CV of pulmonary blood flow. (b) Calculated values of arterial saturation (solid lines) and venous saturation (dashed lines) for conditions of rest, moderate, and heavy exercise as a function of the CV of pulmonary blood flow. The results imply that in exercise, the CV has to be in the range of 0.5 to 1 to maintain adequate tissue oxygen supply and to support the observed arteriovenous saturation differences.