File:Human lung stages 01.jpg

Summary

Overview of lung development

Development of the airways and blood vessels in humans. Lung development is subdivided into morphologically defined stages (blue). These stages are correlated to the development of the airways (black) and blood vessels (red). On average a human airway ends after 23 generations in an alveolar saccule. Because the shape of the lung is defined by the shape of the thorax and not by the branching pattern of the airways, a range of 18–30 generations has been observed. A capillary plexus surrounding the growing lung buds give rise to the pre-acinar arteries by the mechanism of vasculogenesis. The intra-acinar arteries are formed by angiogenesis. An acinus is defined as a small tree of airways served by a most distal purely conducting airway (terminal bronchiole). A ventilatory unit is defined as a tree of alveolar ducts served by a most distal respiratory bronchiole. In mice and rats the acini and the ventilatory units are the same entity because they do not possess any respiratory bronchioles.

(text from figure information)

Reference

Schittny JC. (2018). How high resolution 3-dimensional imaging changes our understanding of postnatal lung development. Histochem. Cell Biol. , 150, 677-691. PMID: 30390117 DOI.

Based on Hislop (2005) and adapted from Schittny (2014).

Copyright

© The Author(s) 2018 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

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https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6267404/figure/Fig1/?report=objectonly