Essential order of lung developmental stages is?
There are four essential lung development stages as described by Moore (2013). First, the pseudoglandular stage entails growth of the intrasegmental bronchial tree between 6 and 16 weeks. Second, during the canalicular stage, from 16 to 26 weeks, the bronchial cailage plates extend peripherally. Each terminal bronchiole gives rise to several respiratory bronchioles, and each of these inturn divides into multiple saccular ducts. Next, the terminal sac stage begins at 26 weeks. During this stage, respiratory bronchioles give rise to primitive pulmonary alveoli . Last, the alveolar stage begins at 32 weeks. During the alveolar stage, the alveolar epithelial lining thins to improve gas exchange. At bih, only approximately 15 percent of the adult number of alveoli is present. Thus, the lung continues to grow, adding more alveoli for up to 8 years. Reference: William's Obstetrics; 24th edition; Chapter 7; Embryogenesis and Fetal Morphological Development.
Pseudoglandular, Canalicular, Terminal sac, Alveolar
Canalicular, Pseudoglandular, Terminal sac, Alveolar
Canalicular, Pseudoglandular, Alveolar, Terminal sac
Pseudoglandular, Canalicular, Alveolar, Terminal sac
General anatomy