What role does surfactant play in the lungs?

Surfactant plays a critical role in the lungs primarily by reducing surface tension within the alveoli. The alveoli are tiny air sacs in the lungs where gas exchange occurs, and they are lined with a thin layer of fluid. Without surfactant, the surface tension created by this fluid can lead to the collapse of the alveoli, a condition known as atelectasis. By lowering surface tension, surfactant ensures that the alveoli remain open and can expand properly during inhalation, facilitating the exchange of oxygen and carbon dioxide.

Furthermore, surfactant allows for more efficient lung mechanics. It helps stabilize the alveoli so that they can remain inflated even when the lung volume decreases, which is crucial during normal breathing. This stabilization is particularly important in premature infants, who may not produce enough surfactant and are at risk for respiratory distress syndrome.

Overall, by reducing surface tension, surfactant improves lung function and supports effective ventilation, making it essential for maintaining healthy respiratory mechanics.