Figure 2.
Oxygen tensions in the body. Reduction of oxygen tensions at different levels of airways, arteries, and tissues after breathing air at sea level and 1.3 ATA and breathing 100% oxygen at sea level and 2.5 ATA. (ATA = atmospheres absolute; PO2 = partial pressure of oxygen; PAO2 = partial pressure of oxygen in alveoli; PaO2 = partial pressure of oxygen in arteries; PtO2 = partial pressure of oxygen in tissues. PmO2 = partial pressure of oxygen in mitochondria. * Estimations through extrapolations).