Various studies have mentioned the presence of the supernumerary muscles of the pharynx that originate from the petrous portion of the temporal bone and get inserted on the superior constrictor muscle. The ninth cranial nerve curves around the posterolateral border of the stylopharyngeus muscle to pass between the superior and middle constrictor muscles and reach the tongue. The lateral border of this recess (lateral glossoepiglottic fold or pharyngoepiglottic fold) is composed of the stylopharyngeus muscle and the palatopharyngeus muscle. The stylopharyngeus muscle has a topographical relationship with the piriform recess, which is the major route for pharyngeal swallowing and serves as the largest pocket providing post-deglutition retention. Some fibers merge with the lateral glossoepiglottic fold while others join with the fibers of the palatopharyngeal muscle and insert into the posterior border of the thyroid cartilage/lamina. Some of the fibers of the stylopharyngeus muscle become lost in the superior and middle constrictor muscles.

On the lateral pharyngeal wall, the stylopharyngeus muscle lies posterior to the superior constrictor muscle and anterior to the buccopharyngeal fascia. During its course, it penetrates the pharyngeal wall between two pharyngeal muscles (superior constrictor and the middle constrictor). There it runs in a longitudinal direction running deep to the superior constrictor muscle and superficial to the middle constrictor muscle.

It runs in a downward direction between the external and the internal carotid arteries. It is the only pharyngeal muscle that has an origin outside the pharyngeal wall. The stylopharyngeus muscle originates from the medial side of the base of a bony projection from the temporal bone, i.e., the styloid process.

Middle pharyngeal constrictor origin