What is a physiological role of surfactant in neonates?

Surfactant plays a crucial role in the lungs of neonates primarily by reducing surface tension within the alveoli. This reduction in surface tension prevents the alveoli from collapsing, particularly during exhalation, thus facilitating efficient gas exchange. When surfactant levels are adequate, the lungs can expand more easily, allowing for improved oxygen uptake and carbon dioxide elimination. Neonates, especially those born prematurely, are at risk of surfactant deficiency, which can lead to respiratory distress syndrome (RDS).

While surfactant does have a role in overall lung function that can indirectly support immune function by improving clearance of pathogens, its primary purpose is directly linked to gas exchange. Other areas such as body temperature regulation or circulatory stability are not functions of surfactant, as these factors are managed by different physiological mechanisms.