How emphysema affects the lungs. Emphysema destroys the walls of <I>alveoli</I> (air sacs) in the lungs. This results in the formation of large air spaces that trap carbon dioxide in alveoli and obstruct the flow of oxygen. The drawings include close-ups of alveoli in a healthy lung and in one with emphysema.
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World Book illustrations by Charles Wellek</P>
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