The lung is the essential organ of respiration in air-breathing vertebrates.
Its principal function is to transport oxygen from the atmosphere into the bloodstream, and to excrete carbon dioxide from the bloodstream into the atmosphere.
This it accomplishes with its mosaic of specialized cells that form millions of tiny, exceptionally thin-walled air sacs where gas exchange takes place.
Lungs also have nonrespiratory functions..
For more information about the topic Lung, read the full article at Wikipedia.org, or see the following related articles:
Note: This page refers to an article that is licensed under the GNU Free Documentation License. It uses material from the article Lung at Wikipedia.org. See the Wikipedia copyright page for more details.

