Why does alveoli produce a surfactant?

Alveoli produce surfactant to reduce surface tension within the tiny air sacs of the lungs, which helps prevent their collapse during exhalation. This surfactant, primarily composed of phospholipids and proteins, allows for more efficient gas exchange by stabilizing the alveoli and ensuring that they remain open even at low lung volumes. Additionally, surfactant plays a crucial role in improving lung compliance, making it easier for the lungs to expand during inhalation.