Postnatal Lung Development Postnatal Development birth-8 year Alveolar period Primary Alveolar Septa Pnmary alveoar septa 3 Alveolar duct Myot:broblasts 'SWE ansitory ducts Terminal bronc Terminal Respiratory bronchiole Respiratory bronchiole Alveoli Capil c 36 weeks D Postnatal Secondary alveolar septa Alveolar ducts and alveoliPostnatal Lung Development Postnatal Development ~ birth – 8 year Alveolar period Secondary alveolar septa Alveolar ducts and alveoli