What is the function of surfactant in the lungs?

Surfactant plays a crucial role in the respiratory system, particularly in the alveoli, which are the tiny air sacs in the lungs where gas exchange occurs. Its primary function is to reduce surface tension within the alveoli. The alveolar walls are lined with a thin layer of liquid, and without surfactant, the surface tension of this fluid would be high enough to cause the alveoli to collapse, making it difficult for the lungs to expand during inhalation.

By decreasing surface tension, surfactant stabilizes the alveoli, preventing them from collapsing, especially during exhalation. This stabilization allows the alveoli to remain open and facilitates efficient gas exchange by providing a larger surface area for oxygen and carbon dioxide to diffuse across. Moreover, proper surfactant function is essential for maintaining the integrity of the lungs and ensuring that breathing is effective and lungs can expand properly with each breath.

Improper surfactant levels or function can lead to respiratory problems, such as neonatal respiratory distress syndrome in premature infants, highlighting surfactant's importance in lung function and overall respiratory health.