inferior constrictor (muscle) of pharynx

(redirected from cricopharyngeal part of inferior constrictor (muscle) of pharynx)

in·fe·ri·or con·stric·tor (mus·cle) of phar·ynx

lowest part of outer "circular" muscle layer of pharynx; origin, outer surfaces of thyroid (thyropharyngeal part [TA]) and cricoid (cricopharyngeal part [TA], musculus cricopharyngeus [TA]; superior or upper esophageal sphincter muscle) cartilages; insertion, pharyngeal raphe in the posterior portion of wall of pharynx; action, narrows lower part of pharynx in swallowing, the cricopharyngeal part has a sphincteric function for the esophagus, allowing some voluntary control of eructation and reflux; nerve supply, pharyngeal plexus (cranial root of accessory nerve via the vagus) and rami of the external and recurrent laryngeal nerves.