Which type of alveolar cell can divide to replace damaged Type I cells?

Type II alveolar cells, also known as septal cells, play a crucial role in the alveolar structure of the lungs. One of their primary functions is to produce surfactant, which reduces surface tension in the alveoli and helps prevent their collapse during exhalation. Importantly, Type II cells also have the ability to divide and differentiate into Type I alveolar cells when needed. This regenerative capacity is vital for maintaining the integrity and function of the alveolar surface, especially in response to damage or injury.

Type I alveolar cells, in contrast, are thin and primarily involved in the exchange of gases between the alveoli and the bloodstream. They have a more limited capacity for regeneration and repair compared to Type II cells. Therefore, when it comes to replacing damaged Type I cells, it is the Type II cells that assume this responsibility through their ability to proliferate and differentiate, making them essential for lung health and recovery from injury.