THE PHARYNX 



349 



attached to the base of the skull, the great cornu of the hyoiil bone, and the 

 thyroid cartilage of the larynx. They are as follows: 



1. The stylo-pharyngeus arises from the inner surface of the tlorsal third of the 

 great cornu of the hyoid bone, passes downward and inward, and enters the wall of 

 the pharynx by passing between the pterygo-pharyngeus and palato-pharyngeus. 

 Its fibers radiate, many passing forward, others inward beneath the hyo-pharyngeus. 

 It raises and dilates the pharynx to receive the bolus in swallowing. 



/^^ 



ebrum 



A'""^ 



j/rerebellum ^ 





^Qp, 



^n. 1 



Septum 

 nasi 



ce 



HyO'glo5SU5 



20 



o^to 



.hv^i^fi^ 



Fig. 254 — Posterior Part of a Sagittal Section of Hf.ad of Horse, Cut about 1 cm. to the Leit of the 



Median Plane. 

 /, Posterior nares; i?, pharyngeal oritice of Eustachian tube; -i, aiiitu? laryngis; 4, entrance to a'.sophagus; 

 6, posterior pillar of soft palate; .5', junction of 6 with its fellow over entrance to oesophagus; 6, epiglottis; 7, body 

 of thyroid cartilage; 5, arytenoid cartilage; 9, 9, cricoid cartilage; W, true vocal cord; 11, false vocal cord; IS, 

 lateral ventricle of larynx; IS, crico-arytenoideus post. s. dorsalis; 14, oesophagus; 15, external carotid artery; IS, 

 hypoglossal nerve; 17, glosso-pharyngeal nerve; 18, great cornu of hyoid bone; 19, Eustachian tube; SO, body of 

 hyoid bone; 21, hyoideus transversus; 22, ridges of hard palate; 2£', soft palate; 23, septum between frontal 

 sinuses; 24, olfactory raucous membrane; 25, sphenoidal sinus; 26, basilar part of occipital bone; 26', supra- 

 occipital; j^T', body of sphenoid bone; 25, pituitary body; 2S, chiasma opticum; i?0, corpora quadrigemina; SI, 

 thalamus; 32, arachnoid; SS, odontoid ligament; 34, posterior auricular muscles. 



2. The palato-pharyngeus arises by means of the aponeurosis of the soft 

 palate from the palate and pterygoid bones. Its fibers pass backward on the lateral 

 wall of the pharynx, and are inserted in part into the upper edge of the thyroid 

 cartilage, in part turn inward to end at the median fibrous raphe. Its action is to 

 shorten the pharynx, and to draw the larynx and oesophagus toward the root of the 

 tongue in swallowing. 



3. The pterygo-pharyngeus is flat and triangular. It lies on the anterior part 

 of the lateral wall of the pharynx. It arises from the pterygoid bone above the 



