Alveolar septum

The alveolar septum is the thin tissue wall separating adjacent pulmonary alveoli, functioning as the primary site for gas exchange in the respiratory system (StatPearls, 2023). It is structurally composed of an epithelial layer (Type I and Type II pneumocytes), a basement membrane, and an interstitial space containing fibroblasts, collagen fibers, and a dense capillary network (NIH, 2022). This "blood-air barrier" is essential for the diffusion of oxygen into the bloodstream and the removal of carbon dioxide. In various pathologies, the alveolar septum undergoes significant structural changes; for example, its destruction is the hallmark of emphysema, while its thickening due to collagen deposition is characteristic of pulmonary fibrosis (PubMed, 2021). Although the septum itself is an anatomical structure and not a single molecular target, it contains numerous therapeutic targets such as TGF-beta receptors and various ion channels that are modulated by drugs like Nintedanib or Pirfenidone to treat interstitial lung diseases.

Other names

Interalveolar septumAlveolar wallParenchymal septum

The alveolar septum is an anatomical structure rather than a single molecular target; drugs associated with this region typically act by modulating specific cellular pathways (e.g., inhibiting tyrosine kinases or inflammatory cytokines) within the septal fibroblasts and epithelial cells to prevent remodeling or inflammation (PubMed, 2021).