What surrounds the alveoli in the lungs?
1 Answer
Jun 19, 2016
Capillaries.
Explanation:
Each alveolus is surrounded by a network of capillaries carrying deoxygenated blood. As the blood flows past the alveoli, carbon dioxide diffuses out of the blood and oxygen diffuses into it, combining with haemoglobin on the red blood cells to make oxyhaemoglobin.