What percentage of alveolar cells are great alveolar cells (Type II)?

Great alveolar cells, also known as Type II alveolar cells, make up approximately 5% of the total alveolar surface area, though they are crucial for the overall function of the lungs. These cells are primarily responsible for the production and secretion of pulmonary surfactant, a substance that reduces surface tension within the alveoli and helps to prevent their collapse during exhalation.

While there are many more Type I alveolar cells, which are thin and primarily facilitate gas exchange, the Type II cells' role in maintaining alveolar stability and surface tension regulation is vital. Their relatively small percentage compared to Type I cells does not diminish their importance in respiratory health.