What are the small air sacs at the end of the airway responsible for gas exchange?

The small air sacs at the end of the airway responsible for gas exchange are the alveoli. These structures are critical to the respiratory system as they provide a large surface area for the transfer of gases between the air and the bloodstream. Alveoli facilitate the exchange of oxygen and carbon dioxide through their thin walls, allowing oxygen to diffuse into the blood while carbon dioxide is expelled from the blood into the air within the alveoli.

Each alveolus is surrounded by a network of capillaries, which are small blood vessels where the actual gas exchange takes place. While bronchioles are part of the airway system leading to the alveoli, they do not themselves engage in gas exchange. Ventilators are mechanical devices used to assist or replace spontaneous breathing and are not structures found in the respiratory system. Understanding the role of alveoli is fundamental to comprehending how respiration and gas exchange occur in the body.