What is the primary factor that maintains the pressure gradient that drives O₂ from the capillaries into the interstitial spaces and into the cells?

Question

Quizplus · Accepted Answer

As cellular metabolism depletes its O₂, the intracellular PO₂ drops below that of the blood entering the tissue capillary. This provides the diffusion gradient by which O₂ diffuses from the tissue capillary blood (PO₂ = 100 mm Hg) to the cells (PO₂ < 40 mm Hg).

What Is the Primary Factor That Maintains the Pressure Gradient