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Table 4 Stages and events during lung development in humans and mice

From: Developmental genetics of the COPD lung

Developmental stage Human gestation age Mouse gestation age Lung development events
Embryonic 4-7 weeks 9-14 days Septation of trachea from oesophagus
Lung bud forms two main bronchi and individual lobes
Supporting structures are formed including bronchial cartilage and smooth muscle
Pseudoglandular 5-17 weeks 14-16.5 days Branching morphogenesis begins
Proximal airway epithelial and mesenchymal differentiation occurs
Canalicular 16-26 weeks 16.5-17.5 days Further branching
Vascularisation and angiogenesis occurs along the airway
Rapid increase in capillary numbers
Respiratory bronchioles and alveolar ducts form
Type II alveolar epithelial cells differentiate
Saccular 24-36 weeks 17.5 days to postnatal day 5 Type I alveolar epithelial cells differentiate
Type II alveolar epithelial cells maturation
Air sacs are developed
Lymphatic network develops
Surfactant begins to be produced
Initial stage of primary septation for formation of alveoli occurs
Alveolar 36 weeks to childhood Postnatal day 5-30 Secondary septation produces alveoli
Increasing levels of surfactant produced
Majority of gas exchange surface is formed
  1. Information on the stages of human and mouse lung development was collected from many sources [42, 107, 121, 122]