Embryology and evolutionary history of the respiratory tract

Samantha White ； Melinda Danowitz ； Nikos Solounias

《Edorium Journal of Anatomy and Embryology》 3期 (2016/01) Pp. 54-62

https://doi.org/10.5348/A04-2016-16-RA-8

摘要

Human respiratory embryology and anatomy often reflects the evolutionary transformation from primitive breathing apparatuses. The gills of fishes are invested with vasculature, muscles, cartilages and nerves, and function in pumping water to facilitate gas exchange. As tetrapods evolve air-breathing respiratory structures, the gills lose their breathing function. However, the associated arteries, veins, nerves, musculature, and cartilaginous support become integrated into the pharynx and head. In the Tiktaalik, a popular proposed transitional species between fishes and tetrapods, both gills and lungs are present. Variations in the anatomy of the larynx allow for differing methods of sound production between birds, reptiles, and mammals, and the changing position of the larynx in humans represents feeding mechanisms in infants, and voice production in adults. Comprehension of the normal embryologic development also facilitates a deeper understanding of congenital anomalies. The respiratory tree originates as a diverticulum off of the proximal endodermal gut tube; failed septation between the lung buds and digestive tract results in an anomalous respiratory/esophageal connection seen in tracheoesophageal fistulas. Combining key features of human lung embryology with comparative respiratory anatomy reinforces the relationship between structure and function, and will facilitate a deeper comprehension of lung development.

關鍵字

Anatomy education ； Embryology ； Evolutionary biology ； Gills ； Lung ； Respiratory