Tue May 01, 2012 By: Harsh1 Peswani

why the lungs alveoli are covered with blood capillaries

Expert Reply
Tue May 01, 2012
Alveoli are covered with blood capillaries so that the exchange of gases can take place between the membranes of the alveoli and the surrounding capillaries. The blood capillaries covering alveoli have a low oxygen and high carbon dioxide concentrations. This allows oxygen to diffuse into the blood and carbon dioxide to diffuse out of the blood.
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