What is the primary function of type II pneumocytes in the alveoli?

Type II pneumocytes play a crucial role in the lungs, primarily through their function of producing surfactant. Surfactant is a complex mixture of lipids and proteins that reduces surface tension in the alveoli, the tiny air sacs where gas exchange occurs. By lowering surface tension, surfactant prevents the alveoli from collapsing during exhalation, thereby maintaining lung stability and ensuring that they can expand easily during inhalation.

This production of surfactant is vital for normal respiratory function. In a healthy lung, surfactant allows for greater efficiency in gas exchange by improving lung compliance and facilitating the re-opening of collapsed alveoli. Without adequate surfactant, issues such as respiratory distress syndrome can occur, particularly in premature infants or individuals with certain lung diseases. Thus, the primary function of type II pneumocytes is indeed to produce surfactant, making the lungs more effective in performing their essential role in respiration.