The actual sites of gas exchange within the lungs are the

This question is incomplete, it lacks options, the options are:

A) bronchioles.

B) terminal bronchioles.

C) pleural spaces.

D) alveoli.

E) interlobular septa.

The correct answer is D) alveoli.

Explanation:

The alveoli are small air sacs that behave like blood filters because they are capable of gas exchange. These are located within the lungs and are the fundamental and functional structure of the respiratory system. The alveoli (rich in oxygen) have the ability to make the exchange through the membrane that divides the alveolar space of the capillary known as the "respiratory membrane", the oxygen present in the external environment passing through these alveoli, reaching the blood, where it combines with hemoglobin from red blood cells, and then is spread throughout the human body. On the other hand, the elimination of carbon dioxide from the body follows the same path, but vice versa, that is, it is eliminated from the blood, passing through the alveoli.

Alveoli

Explanation:

Gaseous exchange takes place in the alveoli of the lung.

As deoxygenated blood travels through the alveoli, excretory product in the form of carbon dioxide diffuses out through the capillaries and oxygen diffuses in the opposite direction. The now oxygenated blood travels form the lung to the left side of the heart where it is pumped to the rest of the body.