ANATOMY

Detailed explanation-1: -Without normal surfactant, the tissue surrounding the air sacs in the lungs (the alveoli) sticks together (because of a force called surface tension) after exhalation, causing the alveoli to collapse.

Detailed explanation-2: -When there is not enough surfactant, the tiny alveoli collapse with each breath. As the alveoli collapse, damaged cells collect in the airways, which makes it even harder to breath. These cells are called hyaline membranes. Your baby works harder and harder at breathing, trying to reinflate the collapsed airways.

Detailed explanation-3: -Surface tension tends to collapse the alveoli, but this is countered by a kind of “coating” that covers the alveolar surface called surfactant. Surfactant reduces the surface tension of water, keeping the alveoli open so that we can breathe easily.

Detailed explanation-4: -The main functions of surfactant are as follows: (1) lowering surface tension at the air–liquid interface and thus preventing alveolar collapse at end-expiration, (2) interacting with and subsequent killing of pathogens or preventing their dissemination, and (3) modulating immune responses.