What is the primary function of surfactants in the body?

Surfactants play a crucial role in the body primarily by lowering surface tension. They are substances that contain both hydrophilic (water-attracting) and hydrophobic (water-repelling) parts, allowing them to reduce the cohesive forces between liquid molecules at the interface. This property is especially important in the lungs, where surfactant reduces the surface tension of the alveoli, preventing their collapse and facilitating gas exchange.

In other contexts, such as in the digestive system, surfactants aid in the emulsification of fats, making them more easily digestible and absorbable. By lowering surface tension, surfactants enhance the ability of liquids to spread and mix, which is essential for numerous physiological processes.