What is one of the functions of the pulmonary surfactant?

Pulmonary surfactant plays a crucial role in maintaining the structural integrity of the alveoli, the tiny air sacs in the lungs where gas exchange occurs. Its primary function is to reduce surface tension within the lungs. By doing this, surfactant prevents the alveoli from collapsing, especially during exhalation when the volume of air decreases. This is important because if alveoli were to collapse, it would be difficult for them to reopen during the next inhalation, leading to impaired gas exchange and potential respiratory distress. The presence of pulmonary surfactant ensures that alveoli can remain stable and maintain their shape, thereby facilitating efficient gas exchange with minimal effort during breathing.

While enhancing gas exchange, trapping pathogens, and producing mucus are important functions in the respiratory system, they are not the primary roles of pulmonary surfactant.