300 million
Why are the alveoli so important?
The tiniest hollow cavities in our lungs are known as alveoli. Their walls are so thin that oxygen can enter into the blood from the lungs, and vice versa for carbon dioxide. One lung contains
Why are the alveoli so important?
The tiniest hollow cavities in our lungs are known as alveoli. Their walls are so thin that oxygen can enter into the blood from the lungs, and vice versa for carbon dioxide. One lung contains