Which structure is the site of gas exchange in the lungs?

Question

Quizplus · Accepted Answer

The alveoli are small, thin-walled sacs that are the site of gas exchange in the lungs. Oxygen from the air is absorbed into the bloodstream through the walls of the alveoli, while carbon dioxide, a waste product of cellular respiration, is released from the bloodstream into the alveoli to be exhaled. The other structures listed (bronchi, bronchioles, trachea, and larynx) are involved in the passage of air to and from the alveoli, but they do not directly participate in gas exchange.

Which Structure Is the Site of Gas Exchange in the Lungs