The lung is composed of endoderm derived epithelial cells that constitute the luminal surface of the airways and alveolar spaces. Ensheathing the epithelium are mesenchymal derivatives including airway smooth muscle, pulmonary fibroblasts, and vascular endothelium. During development, the epithelium and mesenchyme are involved in a complex circuit of paracrine and autocrine signals that act to drive morphogenesis and patterning of the developing airway structure. The lung initially arises from the anterior foregut endoderm region, which itself arises from the definitive endoderm that develops soon after gastrulation. .
Citation:Lessons from development for directing lung endoderm differentiation in pluripotent stem cells Rachel S. Kadzik and Edward E. Morrisey Cell Stem Cell. Author manuscript; available in PMC 2013 Apr 6. Published in final edited form as: Cell Stem Cell. 2012 Apr 6; 10(4): 355–361. doi: 10.1016/j.stem.2012.03.013 PMCID: PMC3366272 NIHMSID: NIHMS367732 PMID: 22482501