Question

What is the function of the sac-like structures present at the end of bronchioles?

• A. Storage of respiratory gases
• B. Exchange of respiratory gases
• C. Protection of lungs
• D. Protection from bacteria

Answer 1

The correct option is B

Exchange of respiratory gases

Alveoli or air sacs are formed at the end of bronchioles. They provide a surface where the exchange of gases can take place. The walls of the alveoli contain an extensive network of blood vessels. The blood brings carbon dioxide from the rest of the body and releases it into the alveoli. The oxygen in the alveolar air is taken up by the blood in the alveolar blood vessels and is transported to all cells in the body.