What role does surfactant play in the lungs?

Surfactant plays a crucial role in the lungs by reducing surface tension in the alveoli. The alveoli are tiny air sacs where gas exchange occurs, and they are lined with a thin layer of fluid. Without surfactant, the surface tension of this fluid could lead to alveolar collapse, especially at low lung volumes. By reducing surface tension, surfactant prevents the alveoli from collapsing and ensures they can expand properly during inhalation. This function is essential for maintaining proper lung mechanics, allowing for efficient gas exchange and overall respiratory function.

This property of surfactant is particularly important because it helps maintain compliance in the lungs. In the absence of sufficient surfactant, as seen in conditions like neonatal respiratory distress syndrome, the alveoli can collapse, leading to difficulty breathing and inadequate oxygenation. Thus, surfactant's primary and vital role in the lungs centers around the management of surface tension within the alveoli.