Which component is essential for the gas exchange process in the alveoli?

Surfactant plays a crucial role in the gas exchange process within the alveoli. It is a substance composed mainly of proteins and lipids that reduces surface tension in the alveoli, the tiny air sacs in the lungs where gas exchange occurs. By lowering surface tension, surfactant prevents the alveoli from collapsing during exhalation, thereby increasing their stability and compliance. This ensures that the alveoli can expand efficiently during inhalation, facilitating a greater surface area for oxygen to diffuse into the blood and for carbon dioxide to be expelled from it.

Without adequate surfactant, the alveoli may collapse or become difficult to inflate, significantly impairing the efficiency of gas exchange. This is particularly important in conditions like neonatal respiratory distress syndrome, where a lack of surfactant leads to severe breathing difficulties.