Aveloli are the structures within the lungs, at the terminal end of bronchioles. They are not blood vessels. Aveoli resemble a cluster of grapes hanging off the smallest branches of a tree, with the tree upside down. The main bronchus in the upper chest is like the tree trunk, the bronchi branch and thin to bronchioles, then end at the aveoli. There O2 and CO2 exchange takes place.
from the aveolus
Veins are the type of blood vessel that drains blood from tissues and returns it to the heart.
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Arteries
Oxygen enters the blood in the alveoli of the lungs
capillary
artery
Pulmonary veins.
isn't it your heart. = )
Veins
No, I think you mean "vein".
This is called an aneurysm.