Pneumocytes (or alveolar cells) are the cells that line the alveoli and comprise of the majority of the inner surface of the lungs.

What do type 1 and type 2 pneumocytes do?

The key difference between type 1 and type 2 pneumocytes is that type 1 pneumocytes are thin and flattened alveolar cells that are responsible for the gas exchange between alveoli and capillaries, while type 2 pneumocytes are cuboidal alveolar cells that are responsible for the secretion of pulmonary surfactants that …

What are pneumocytes made of?

Most of the alveolar surface is covered by simple squamous cells known as type I pneumocytes (Figure 1-9). These cells have a small nucleus with highly branched cytoplasmic processes covering 4000 to 5000 µm2.