No. Once blood reaches the alveoli it will immediately start to release CO2 to the air in our lungs and absorb O2 from the air in our lungs. This means that the PCO2 will be higher in the blood of the pulmonary artery than in the blood of the alveolus. If this were not so, then passing blood through the alveoli would be pointless.
C02:alveoli
In the alveoli
our total blood volume is unevenly distributed amongst the arteries, veins and capillaries. The heart, arteries , pulmonary and systemic circuits contain about 1.5 liters of whole blood. The venous system contains 3.5 liters, which is circulating within the liveer, bone marrow and skin.
alveoli son..
Right side of the heart is involved in pulmonary circulation. This circulation is called, at times, as lesser circulation, as against the greater or systemic circulation. Blood that flows through the lesser and greater circulation is same in amount. But there is gross difference between the two. You have interstitial compartment in the systemic circulation. This is maintained through high blood pressure there. You do not have the same in pulmonary circulation. What you need here is simple blood flow, with out formation of the interstitial compartment. For that you have blood systolic blood pressure of about 25 mm of mercury. The blood pressure in the capillaries is about 15 mm of the mercury. The oncotic pressure of the blood proteins is about 22 mm of mercury. So very little fluid is leaked out to keep the alveoli wet. Some times in diseased condition more fluid is leaked out in the alveoli, to give rise to pulmonary oedema.
i would say capillaries...
Pulmonary and systemic
Capillaries service cells, arteries and veins transport blood to and from capillaries, respectively.
greater concentration of oxygen in the air sacs of the lungs than in the capillaries.
Capillaries are tiny blood vessels. They need to have a greater surface area to volume ratio because they need to diffuse oxygen quicker.
African-Americans have been shown to be at greater risk for arterial occlusion than other racial groups in the United States.
deoxygenated blood goes to the lungs which then goes down into the bigger bronchi and the get a little smaller into the bronchioles and then goes into the alveoli which is a grape like cluster where the gas exchange takes place and the bad goes out and the good air stays in. this is a dumbed down version of what really happens so if you like my answer you do or you may want to look it up on the internet to get a little better explinaiton