Are the alveoli part of the conducting zone or respiratory zone?

The alveoli are indeed classified as part of the respiratory zone of the respiratory system. The primary function of the respiratory zone is gas exchange, and this is where the alveoli play a crucial role. The alveoli are tiny air sacs located at the end of the bronchial tree, specifically within the lungs, and they provide a large surface area for oxygen and carbon dioxide exchange between the air and the bloodstream.

In contrast, the conducting zone includes structures that primarily serve to filter, warm, and humidify the air as it travels toward the lungs, but they do not participate in gas exchange. The conducting zone consists of the nasal cavity, pharynx, larynx, trachea, bronchi, and bronchioles, leading up to the terminal bronchioles, which precede the respiratory zone.

Therefore, designating the alveoli as part of the respiratory zone is correct because they are the final destination for inhaled air, where the crucial process of respiration occurs.