Final answer:
Pulmonary surfactant reduces surface tension in the lungs and helps with lung inflation. In newborn infants, a lack of surfactant can lead to hyaline membrane disease. Applying surfactant can improve their chances of survival.
Step-by-step explanation:
Pulmonary surfactant is a substance that reduces the surface tension in the lungs, making it easier for them to inflate. It is essential for proper lung function and gas exchange. For newborn infants and premature babies, the lack of sufficient surfactant can lead to hyaline membrane disease, which makes it difficult for them to inflate their lungs. The application of surfactant can help treat this condition and improve their chances of survival.