<prompt> What is the paial pressure for oxygen in the expired air?116 mm Hg158 mm Hg100 mm Hg0.3 mm Hg  <response>: Paial pressure of O2 in expired air PE O2 - 116 mm Hg Gaseous concentration its paial pressure in alveoli: 1. Oxygen: Concentration paial pressure controlled by, Rate of absorption of O2 into blood Rate of entry of new O2 into lungs by ventilatory process. Values: Paial pressure of O2 in inspired air Pi O2 158 mm Hg Paial pressure of O2 in alveolar air PA O2 100 mm Hg Calculated by Alveolar gas equation. Paial pressure of O2 in expired air PE O2 116 mm Hg 