Alveolar Structure Diagram: Key Cell Types and Functions in the Lungs #279108 (License: Personal Use)

The image is a cross-sectional schematic of a pulmonary alveolus, with type I pneumocytes forming the thin gas-exchange barrier, type II pneumocytes producing surfactant (shown in blue vesicles), and capillary endothelium facilitating oxygen diffusion. A macrophage patrols the alveolar lumen, while fibroblasts reside in the interstitium; red blood cells (RBCs) are depicted within capillaries to emphasize gas transport. The thickness of type I cells and endothelium is exaggerated 3× for clarity.

Used in medical textbooks, physiology lectures, and online educational resources to teach respiratory anatomy and function; targets students, clinicians, and researchers seeking to understand alveolar microstructure and cellular roles in gas exchange and immunity.