Definition

Developement stages

 Embyonic (26 days-6 weeks): development of major airways
 Pseudoglandular (6-16 weeks): development of airways to terminal bronchioles
 Acinar or canalicular (16-28 weeks): development of acinus and its vascularization
 Saccular (28-34 weeks): subduvision of saccules by secondary crests
 Alveolar (34-39 weeks): alveolar acquisition

References

 Hislop A. Developmental biology of the pulmonary circulation. Paediatr Respir Rev. 2005 Mar;6(1):35-43. PMID: #15698814#

 Shannon JM, Hyatt BA. Epithelial-mesenchymal interactions in the developing lung. Annu Rev Physiol. 2004;66:625-45. PMID: #14977416#

 Chuang PT, McMahon AP. Branching morphogenesis of the lung: new molecular insights into an old problem. Trends Cell Biol. 2003 Feb;13(2):86-91. PMID: #12559759#