na·so·phar·ynx. The part of the pharynx that lies above the soft palate; anteriorly it opens into the nasal cavity; inferiorly, it communicates with the oropharynx through the pharyngeal isthmus; laterally it communicates with tympanic cavities through auditory tubes. Synonym(s): epipharynx.he uppermost of the three regions of the throat (pharynx), situated behind the nasal cavity and extending from the posterior nares to the level above the soft palate. On the posterior wall of the nasopharynx, opposite the posterior nares, are the pharyngeal tonsils.