([Fig. 96]).—M. glossopharyngeus (i).
Origin.—Some fibres on the ventral and lateral part of the genioglossus (f) leave that muscle near its caudal end. They form a thin band of diverging fibres which pass outside of the cranial horn of the hyoid. A similar sheet of fibres leaves the midventral part of the styloglossus (e). The two sheets unite and the united muscle crosses the hyoid, turns dorsad, and has its
Insertion into the median dorsal raphe of the pharynx.
Action.—Constrictor of the pharynx.
M. constrictor pharyngis inferior (k).—A thin sheet of muscle covering the sides of the pharynx at its caudal end.
Origin from the lateral surfaces of the thyroid and the cricoid cartilages. The fibres pass dorsad and craniad, the cranial ones covering the fibres of the middle constrictor (j).
Insertion.—The median longitudinal raphe on the dorsum of the pharynx. The caudal fibres are transverse and continuous with the circular fibres of the œsophagus. The cranial fibres may pass as far as the base of the sphenoid.
Action.—Constrictor of the pharynx.
M. constrictor pharyngis medius (j).—A thin sheet which covers the middle part of the lateral surface of the pharynx.
Origin.—The ventral two pieces of the cranial horn and the whole of the caudal horn of the hyoid. The fibres diverge, passing dorsad.