Specializations of the human upper respiratory and upper digestive systems as seen through comparative and developmental anatomy

摘要: The human upper respiratory, or aerodigestive, tract serves as the crossroads of our breathing, swallowing and vocalizing pathways. Accordingly, developmental evolutionary change in any these functions will, necessity, affect others. Our studies have shown that position neck mammalian larynx is a major factor determining function this region. Most mammals, such closest relatives nonhuman primates, exhibit positioned high neck. This permits an intranarial to be present creates largely separate respiratory digestive routes. While infant humans retain basic pattern, descent considerably alters configuration. Adult have, accordingly, lost separation routes, but gained increased supralaryngeal region pharynx which allows for production varied sounds speech. How has changed during evolution been difficult assess due absence preserved soft-tissue structures. relationship between basicranial shape laryngeal living mammals can valuable guide reconstruct ancestral humans. Based on findings we examined basicrania fossil ancestors—from over two million years ago near recent times—and reconstructed pharyngeal early forms. allowed us insight into how ancestors may breathed swallowed, when anatomy necessary speech evolved.