Type II alveolar cells, also known as type II pneumocytes, are specialized cells located in the alveoli of the lungs. They play a crucial role in the respiratory system by producing and secreting surfactant, a substance that reduces surface tension in the alveoli. This helps prevent the alveoli from collapsing during exhalation, ensuring efficient gas exchange. In addition to surfactant production, Type II alveolar cells also contribute to the repair and regeneration of the alveolar epithelium after injury. They can differentiate into Type I alveolar cells, which are responsible for gas exchange, thus playing a vital role in maintaining lung function and health.