It's a complex mixture of phospholipids, proteins, and other lipids. The primary phospholipid in surfactant is dipalmitoylphosphatidylcholine (DPPC), which is responsible for its surface-active properties.
Here's how surfactant works:
* Reduces surface tension: Surfactant molecules align at the air-water interface in the alveoli, reducing the surface tension of the fluid lining the alveoli. This prevents the alveoli from collapsing during exhalation.
* Prevents alveolar collapse: Without surfactant, the surface tension of the fluid would be so high that the alveoli would collapse during exhalation. This would make it very difficult to breathe.
* Improves gas exchange: By keeping the alveoli open, surfactant also helps to improve gas exchange by increasing the surface area available for diffusion of oxygen and carbon dioxide.
Surfactant is essential for normal lung function. In premature babies, surfactant production may be insufficient, leading to respiratory distress syndrome (RDS).
