Lung parenchyma

The **lung parenchyma** is the essential functional tissue of the lung comprising the thin-walled alveoli and their closely associated capillaries, forming a very large surface area for gas exchange between air and blood[1][5]. It consists of elastic and collagen fibers embedded in an extracellular matrix, which provide the structural and mechanical properties necessary for lung elasticity and compliance[1][3][4]. The parenchyma houses a variety of cell types—including epithelial cells, fibroblasts, endothelial cells, immune cells, and smooth muscle elements—that collectively maintain gas exchange and respond to physiological and pathological challenges[2][3]. The organization and content of extracellular matrix proteins such as collagen and elastin influence parenchymal stiffness and mechanics and are altered in diseases like fibrosis and COPD[1][3]. Diseases affecting the lung parenchyma include fibrotic diseases, infections, and inflammatory conditions, but it is not a molecular target, enzyme, receptor, or druggable protein; rather, it is an anatomical structure composed of many cellular and acellular components[5]. Note: "Lung parenchyma" is not a molecular target, receptor, enzyme, or similar therapeutic target, but rather a tissue region or compartment. Thus, using it as a "target" in drug development is imprecise, and the fields for molecular interaction, mechanism of action, biomarkers, and safety concerns do not apply[5][1][3].

Other names

Pulmonary parenchymaGas-exchanging tissue of the lungEssential lung tissue