Surfactant is a product which is secreted by the lungs. Its purpose is to reduce the lungs surface tension. Without surfactant the moist surfaces of the lungs would have such a high surface tension that the smaller alveoli would collapse.
Surfactant reduces surface tension, so that the alveoli in the lungs are able to expand. It is essentially a biological detergent.
Surfactant reduces surface tension. Without surfactant, the wet...