I could not find an answer link. There is 21% oxygen(O2) in the air we
take into our lungs. PAO2 is the O2 concentration in the alveoli,
which are the smallest divisions in the lungs,where exchange of oxygen
and carbon dioxide(CO2) takes place between the air we take in and
blood in the arteries(blood vessels carrying blood from the heart to
tissues/organs). PaO2(note the small a) is the oxygen concentration in
the arteries. So the exchange of oxygen occurs, depending on the
gradient, called as A-a gradient, between the alveoli and the
arteries, i.e. from the high O2 in alveoli to the low O2 conc. in the
arteries as PAO2 is higher than PaO2.Please let me know if you need
furhter explanation of the above. |
