THE PHAR YXX. 



375 



These are universally regarded as constrictors. 



Sometimes two fasciculi are observed in the crico-pharyngeus. The 

 supplementary fasciculus is somewhat thin, and arises from the posterior 

 border of the bezil of the cricoid cartilage, ascending parallel to the oeso- 

 phagus to terminate with the principal fasciculus. 



ARYTENO-PHARYNGEUS. By this name has been described a small fasci- 

 culus, extremely thin in Solipeds, which extends from the posterior border 

 of the arytenoid cartilage to the origin of the oesophagus. To expose this 

 muscle, which we do not look upon as constant, it is necessary to turn the 

 oesophagus forward on the superior surface of the pharynx. 



STYLO-PHARYNGEUS. -A narrow band which descends from the great 

 hyoideal branch to the side of the pharynx, where it is confounded with 

 the pterygo-pharyngeus. It elevates the pharynx in contracting, and it is 

 also regarded as a dilator ; though the disposition of the parietes of the 

 pharynx, and the feeble volume of this muscle, scarcely allows it to play 

 any efficacious part in the dilatation of that cavity. It may only produce 

 a very slight infundibulum where it is inserted. The real dilating agent 

 of the pharyngeal cavity is the alimentary bolus, which is pushed into it by 

 the action of the tongue (Fig. 149, 5). 



Fig. 176. 



MUSCLES OF THE PHARYNGEAL AND HYOIDEAL REGIONS. 



1, Glenoid cavity of temporal bone ; 2, Superior extremity of styloid bone ; 3, 

 Tensor palati with its pulley, 5 j 4, Stylo-pharyngeus ; 6, Palato-pharyngeus ; 7, 

 Circumflexus palati ; 8,. Pterygo-pharyngeus ; 9, Sublingual gland ; 10, Portion 

 of hyoid bone ^ 11, Hyo-pharyngeus ; 12, Thyro-pharyngeus ; 13, Crico-pharyn- 

 geus; 14, Portion of stylo-pharyngeus ; 15, Hyo-thyroideus ; 16, Styloid bone; 

 17, Crico-arytenoideus lateralis ; 18, (Esophagus ; 19, Sterno-maxillaris and 

 hyoideus, and subscapulo hyoideus ; 20, Trachea ; 21, Hard palate ; 22, Tongue. 



It is not rare to meet a second stylo-pharyngeus muscle terminating on 

 the same point as the first, but proceeding from the inferior extremity of the 

 large branch of the os hyoides, instead of its upper part. 



Certain anatomists designate it the inferior kerato-pharyngeus, and con- 

 sider it as a constrictor of the pharynx. It sometimes exists only on one side. 



3. Vessels and nerves. The blood sent to the pharynx comes from the 



