Where does the exchange of carbon dioxide and oxygen with the blood occur
the bronchi
bronchiole
alveolar ducts
alveolar sacs
It seems that you are asking different questions under different names. You can ask more than one question on a post.
Think of it as transportation. Where does the "end of the line" occur?
If that doesn't help, try
http://www.answers.com/topic/air-sac
I hope this helps. Thanks for asking.
The exchange of carbon dioxide and oxygen with the blood occurs in the alveolar sacs. These small air sacs are located at the ends of the bronchioles in the lungs. They have thin walls, which are surrounded by a network of tiny blood vessels called capillaries.
When we inhale, oxygen from the air enters the alveolar sacs and diffuses across the thin walls into the capillaries. At the same time, carbon dioxide from the blood in the capillaries diffuses into the alveolar sacs and is then exhaled out of the body during exhalation.
So, to answer your question, the exchange of carbon dioxide and oxygen with the blood occurs in the alveolar sacs.