Definition of Pneumocyte

Pneumocyte:These are specialized cells that form the inner lining of the alveoli, which are the tiny air sacs in the lungs. The alveoli contain two distinct types of pneumocytes:Type 1 Pneumocyte: This cell plays a key role in facilitating the exchange of gases, such as oxygen and carbon dioxide, within the alveoli. It is characterized by its large, thin structure that covers an extensive surface area. Type 1 pneumocytes are vulnerable to numerous toxic substances and lack the ability to self-replicate.Type 2 Pneumocyte: This cell is essential for producing and secreting surfactant, a substance that lowers the surface tension of pulmonary fluids and aids in maintaining the elasticity of the lungs. Type 2 pneumocytes are smaller in size and have the capability to replicate within the alveoli, allowing them to replace damaged type 1 pneumocytes when necessary.

Medical Definition & Meaning