Arrange the following in order from highest to lowest po2. a. po2 of pulmonary veins b. po2 of pulmonary artery c. po2 of alveolar air

Order from higher to lower partial pressure is equal to  

a.PO2 of pulmonary veins

b.PO2 of alveolar air  

c.PO2 of pulmonary artery

Explanation:

In pulmonary artery the blood is impure i.e deoxygenated due to which the partial pressure of oxygen is lower in pulmonary artery as compared to the pulmonary alveoli which has pure or oxygenated blood.  

The PO2 of Alveoli is equal to 104 mmHg while the PO2 of pulmonary artery is 40 mmHg.

For alveolar air, the partial pressure is equal to 100 mmHg

Thus, order from higher to lower partial pressure is equal to  

a.PO2 of pulmonary veins

b.PO2 of alveolar air  

c.PO2 of pulmonary artery