What is surfactant and what is its function?

Surfactant is a mixture of fat and proteins made in the lungs. Surfactant coats the alveoli (the air sacs in the lungs where oxygen enters the body). This prevents the alveoli from sticking together when your baby exhales (breathes out).

Its classically known role is to decrease surface tension in alveolar air spaces to a degree that facilitates adequate ventilation of the peripheral lung.