Isthmus of the fauces
A part of the oropharynx directly behind the mouth cavity, bounded superiorly by the soft palate, laterally by the palatoglossal arches, and inferiorly by the tongue. The fauces are regarded as the two pillars, formed by the palatoglossus and the palatopharyngeus muscle, respectively, and covered with mucous membrane.
Syn: oropharyngeal isthmus
Word origin: 1550s, from Latin isthmus, from Greek isthmos “narrow passage, narrow neck of land,” especially that of Corinth, of unknown origin, perhaps from eimi “to go” + suffix –thmo (cf. ithma “a step, movement”).