What is Type 2 Pneumocyte hyperplasia?
What is Type 2 Pneumocyte hyperplasia?
In summary, prominent type 2 pneumocyte hyperplasia can occur in the settings of spontaneous pneumothorax and, similarly to other reactive processes such as squamous metaplasia, can mimic epithelial malignancy in the lung.
What does Type II Pneumocyte do?
Type 2 pneumocyte: The cell responsible for the production and secretion of surfactant (the molecule that reduces the surface tension of pulmonary fluids and contributes to the elastic properties of the lungs).
What are alveoli type 2 cells?
Type II cells are defenders of the alveoli by secreting surfactant, keeping the alveolar space relatively free from fluid, serving as progenitor cells to repopulate the epithelium after injury, and providing important components of the innate immune system.
What does Type II Pneumocyte damage cause?
Apoptosis of type II epithelial cells could interfere with the synthesis of surfactant, thereby allowing alveolar collapse. Type I pneumocytes would also be reduced in number, causing denuding of the alveolar capillary membrane, and leading to the development of fibrosis and parenchyma remodelling.
Can type 2 pneumocytes regenerate?
Type II epithelial cells are small cuboidal cells which usually reside in the corners of the alveolus, covering roughly 2% of the alveolar surface area. Type II pneumocytes are known to produce surfactant and regenerate alveolar epithelium after injury.
What is the difference between Type 1 and Type 2 alveolar cells?
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 is the difference between type I and type II alveolar cells?
Are type 2 alveolar cells phagocytic?
Two types are pneumocytes or pneumonocytes known as type I and type II cells found in the alveolar wall, and a large phagocytic cell known as an alveolar macrophage that moves about in the lumens of the alveoli, and in the connective tissue between them.
Which Pneumocyte can regenerate?
Type II pneumocytes
Type II pneumocytes are known to produce surfactant and regenerate alveolar epithelium after injury. In healthy lungs, type I and type II cells exist in a 1:1 ratio.
Can Covid give you COPD?
With this, COVID-19 can cause overall worsening of these conditions, such as asthma, chronic obstructive pulmonary disease (COPD), interstitial lung disease, etc.
What is the difference between Type 1 and Type 2 pneumocytes?
Type 2 pneumocytes represent 60% of the alveolar cell population numerically, but occupy only 5–10% of the alveolar surface area. Unlike the thin, flat type 1 cells, type 2 pneumocytes are rounded cells which are commonly located in obtuse angles in the polygonal alveolus (Fig. 10.15a).
What is micronodular type II pneumocyte hyperplasia?
Micronodular type II pneumocyte hyperplasia is largely, though not exclusively, confined to patients with tuberous sclerosis, of which it is a particularly rare manifestation.80–88 It may be seen in otherwise normal lungs or in association with pulmonary lymphangioleiomyomatosis.
What are lamellar bodies in Type II pneumocytes?
They comprise 25% of the cytoplasm of type II pneumocytes. These lamellar bodies are meant to be the substrate of the synthetic activity of the pneumocytes. These structures are equated with the surface active substances (surfactant) that are formed in the cytoplasm of these cells.
What is the role of targethgf in type 2 pneumocyte proliferation?
HGF plays a central role in type 2 pneumocyte proliferation that is similar to its role in liver regeneration, perhaps not surprising since liver and lung are both derivatives of the embryonic endoderm.
