Why partial pressure of O_{2 }in expired air is 116 mm Hg and that of CO_{2 }is around 32 mm Hg. Why partial pressure of oxygen is more than expected as most of the oxygen was already used by the tissues during breathing and respiration.

Why partial pressure of O_{2 }in expired air is 116 mm Hg and that of

1.	Why partial pressure of O_{2 }in expired air is 116 mm Hg and that of CO_{2 }is around 32 mm Hg. Why partial pressure of oxygen is more than expected as most of the oxygen was already used by the tissues during breathing and respiration.
Answer» Why partial pressure of O_{2 }in expired air is 116 mm Hg and that of CO_{2 }is around 32 mm Hg. Why partial pressure of oxygen is more than expected as most of the oxygen was already used by the tissues during breathing and respiration.