Question

Fill in the following blank with a suitable word:

The actual exchange of gases takes place in the ______ of the lungs.

Answer 1

The actual exchange of gases takes place in the alveoli of the lungs.

Explanation:

The alveoli are millions of microscopic, thin-walled air sacs wrapped in tiny blood vessels (capillaries). While the rest of the respiratory system serves as a pathway for air to move, the alveoli are the only site where oxygen physically crosses into the blood and carbon dioxide leaves it.