Air Sacs

At the end of the bronchial tree the air sacs [alveoli] can be found. One can imagine the transition area between the smallest airways and the air sacs as grapes on a vine. However, our air sacs are not-contrary to the grapes- "separated" (each grape hanging on a single stalk) but connected with each other by small passages or interalveolar connections [Pores of Kohn]. These are among other things important for a balanced air distribution in the air sacs.

Did you know?

There are about 200-300 million air sacs in our lungs. If you sliced them open and put them next to each other, this would make a total surface area of about 80-140 square metres. That is roughly the size of a tennis court, all of which is in your rib cage.