336 



DR. C. F. SONNTAG ON THE ANATOMY, 



in front with the buccinator, both being attached to the pterygo- 

 mandibular ligament. It is attached to the mylo-hyoid line on 

 the mandible, the internal pterygoid plate, the base of the tongue, 

 the mucous membrane of the floor of the mouth and the bucco- 

 pharyngeal aponeurosis. The lower border is overlapped by the 

 middle constrictor, and the stylo-pharyngeus passes between 

 them as a few separate, but thick, bundles of fibres. Some of 

 these fibres pass into, and blend with, the outer surface of the 

 superior constrictor. The upper part of the muscle is separated 

 by a large sinus of Morgagni from the base of the skull, but the 

 levator palati and tensor palati, which are situated therein, lie 

 horizontally, whereas the}'' are more vertical in Man, and of 

 smaller size. The constrictor is attached above and behind into 



Text-figure 32. 



S.HJ 



A. B. 



The omo-hyoid muscle (A) and the anatomy of the submental region (B). A.B.O.j 

 P.L.O., and P.M.O: anterior, postero-lateral and postero-mesial bellies of 

 the omo-hyoid muscle; F.S : fatty septum; L.A: lingual artery; N.G.H : 

 nerves to the genio-hyoid muscle; H.B : hyoid bone; S.H. and S.T : sterno- 

 hyoid and sterno-thyroid muscles ; IX and XII : cranial nerves. Other 

 letters as in text-fig. 31. 



the basis cranii. It is difficult, and in some places impossible, to 

 separate the superior constrictor from the stylo-glossus muscle 

 which courses downwards and forwards on its outer surface. 



A well-marked bundle of fibres passes towards the angle of the 

 mouth. The middle constrictor of the pharynx arises from the 

 deep surface of the hyoid bone in the angle between the greater 

 and lesser cornua, and it is inserted into the mid-dorsal line of 

 the pharynx, its fibres mingling with those of the opposite 

 muscle. It is overlapped by the inferior constrictor. Some fibres 

 of the stylo-pharyngeus pass into its outer surface. Between the 

 superior and middle constrictors there is a non-muscular area 

 anteriorly. The inferior constrictor of the pharynx arises as in 



