The aveolus is surrounded by capillaries. So capillaries carry deoxygenated blood to the alveolus where the oxygen from the alveolus diffuses into the blood in the capillaries. The deoxygenated blood is now oxygenated and is carried out of the lung via capillaries that then merge into the pulmonary vein.
In other words, alveolus does not have oxygenated blood it just puts oxygen into the deoxygenated blood hat this brought in.
Alleles
I had bio a while ago though so I could be wrong...
It is the central nervous system that takes charge of the body's involuntary functions outside conscious awareness. It is this system that is responsible for all of the body's involuntary acts, such as breathing, blinking, etc.