Insertion into the median dorsal raphe of the pharynx. The cranial fibres are inserted into the base of the sphenoid bone. The muscle covers part of the stylopharyngeus (l) and the superior constrictor ([Fig. 66], f, [page 112]) and is partly covered by the glossopharyngeus ([Fig. 96], i).
Action.—Constrictor of the pharynx.
M. stylopharyngeus (l).
Origin from the tip of the mastoid process of the temporal bone and from the inner surface of the cartilaginous piece between the tympanohyal and the stylohyal bones. The parallel fibres form a flat band which passes ventrocaudad over the outer surface of the constrictor superior.
Insertion.—The ventral fibres pass beneath the middle constrictor (j) at its cranial border and, continuing toward the middle line of the pharynx, gradually lose themselves among the fibres of the superior constrictor. The dorsal fibres pass onto the outer surface of the middle constrictor and are lost among its fibres.
Action.—Constrictor of the pharynx.
M. constrictor pharyngis superior or pterygopharyngeus ([Fig. 66], f, [page 112]).—A flat, triangular sheet beneath the constrictor medius.
Origin.—The tip of the hamular process of the pterygoid bone. The muscle passes caudad, the fibres diverging, and dips beneath the cranial border of the constrictor medius.
Insertion into the median dorsal raphe of the pharynx. The dorsal fibres are inserted into the base of the sphenoid. The ventral fibres pass lengthwise of the pharynx, closely connected with those of the stylopharyngeus ([Fig. 96], l), and finally reach the level of the larynx.
Action.—Constrictor of the pharynx.