16 week fetal pulmonary system

3D Model

-From a structural and functional perspective, the respiratory system is most logically considered as having conducting and gas exchange components, with the bifurcating airways and accompanying pulmonary arteries (PAs) conducting air and blood to peripheral capillary-lined airspaces for gas exchange.

Reference : 1-netters atlas of human embryology (updated edition) 2-larsens human embryology (6th edition) 3-the anatomy of human embryo electron microscope (1st edition)