What is the function of the alveoli in the lungs?

What is the function of the alveoli in the lungs?

• A. To facilitate oxygen absorption from blood
• B. To facilitate gas exchange between air and blood
• C. To produce mucus for air filtration
• D. To help regulate blood pH

Answer: (B)

The primary function of the alveoli in the lungs is to facilitate gas exchange between air and blood. Alveoli are tiny, balloon-like structures that increase the surface area available for this exchange process. When air is inhaled, oxygen travels into the alveoli, where it diffuses across the thin walls of these structures and into the surrounding capillaries. At the same time, carbon dioxide in the blood diffuses out of the capillaries into the alveoli to be exhaled. This crucial process allows the body to obtain oxygen necessary for cellular metabolism and to remove carbon dioxide, a waste product of that metabolism. Other options do not correctly describe the primary function of the alveoli. While mucus production and air filtration occur in other parts of the respiratory system, such as the nasal passages and bronchi, it is not a role attributed to the alveoli. Similarly, while the respiratory system plays a role in regulating blood pH indirectly through gas exchange, the alveoli's main focus is not on this regulatory function. Instead, their specialized structure and positioning make them essential for effective and efficient gas exchange, which is vital for maintaining overall respiratory and body health.

The primary function of the alveoli in the lungs is to facilitate gas exchange between air and blood. Alveoli are tiny, balloon-like structures that increase the surface area available for this exchange process. When air is inhaled, oxygen travels into the alveoli, where it diffuses across the thin walls of these structures and into the surrounding capillaries. At the same time, carbon dioxide in the blood diffuses out of the capillaries into the alveoli to be exhaled. This crucial process allows the body to obtain oxygen necessary for cellular metabolism and to remove carbon dioxide, a waste product of that metabolism.

Other options do not correctly describe the primary function of the alveoli. While mucus production and air filtration occur in other parts of the respiratory system, such as the nasal passages and bronchi, it is not a role attributed to the alveoli. Similarly, while the respiratory system plays a role in regulating blood pH indirectly through gas exchange, the alveoli's main focus is not on this regulatory function. Instead, their specialized structure and positioning make them essential for effective and efficient gas exchange, which is vital for maintaining overall respiratory and body health.