How does surfactant contribute to lung function in newborns?

Surfactant plays a critical role in newborn lung function by reducing surface tension within the alveoli. This reduction in surface tension is essential because it prevents the alveoli—the tiny air sacs in the lungs—from collapsing, particularly at the end of exhalation. By ensuring that the alveoli remain open and stable, surfactant facilitates efficient gas exchange, allowing oxygen to enter the bloodstream and carbon dioxide to be expelled.

In the absence of sufficient surfactant, which can occur in premature infants, the increased surface tension can lead to atelectasis (collapse of alveoli) and impaired gas exchange. This condition is a key factor in neonatal respiratory distress syndrome, which highlights the importance of surfactant in maintaining proper lung function and oxygenation in newborns.

The other options do not accurately describe the function of surfactant: minimizing oxygen intake and blocking airways do not support lung function, and increasing alveolar pressure would not promote optimal gas exchange. Thus, understanding the role of surfactant in reducing surface tension is vital for recognizing its importance in neonatal care.