During intense exercise, alveolar PO2 remains relatively stable despite increased ventilation and O2 consumption. Which mechanism explains why alveolar PO2 doesn't drop significantly?

💡 Explanation

Ventilation-perfusion matching dynamically adjusts blood flow to alveoli with the highest oxygen levels; therefore, even with increased consumption, efficient gas exchange maintains alveolar PO2, because this mechanism optimizes the ventilation-perfusion ratio, rather than relying on diffusion rates alone or pH effects.

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