1136 



DIGESTIVE SYSTEM 



and in front of the tonsil, forming the glosso-palatine arch of the fauces. It reaches the side 

 of the tongue at the junction of its middle and posterior thirds, and some of its fibres continue 

 forward to join with those of the stylo-glossus and hyo-glossus, while the majority pass medially 

 to become continuous with the transversus ILnguaj. Nerve-supply. — From the pharyngeal 

 branches (plexus) of the vagus. Action. — (1) To draw the sides of the soft palate downward; 

 (2) to draw the sides of the tongue upward and backward. The combination of these actions 

 tends to constrict the faucial isthmus. (The origin and insertion of the glosso-palatinus as 

 given above are often described as reversed.) 



The pharyngo-palatinus (palato-pharyngeus) — named from its attachments — is a thin 

 sheet. Origin. — (1) From the aponeurosis of the soft palate by two heads which are separated 

 by the insertion of the levator veli palatini; (2) by one or two narrow bundles from the lower 

 part of the cartilage of the auditory (Eustachian) tube (salpingo-pharyngeus) . Insertion. — (1) 

 By a narrow fasciculus into the posterior border of the thyreoid cartilage near the base of the 

 superior cornu; (2) by a broad expansion into the fibrous layer of the pharynx at its lower part. 



Fig. 894. — The Muscles of the Pharynx, Lateral View. 



Medial lamina of 



pterygoid process 



Constrictor pharyngis 



superior 



Pterygo-mandibular raphe 



Stylo -hy Old bgament 



Conslrictor pharyngis 

 medius 



Stylo-pharyngeus 



Constrictor pharyngis 

 inferior 



(Esophagus 



Buccinator 



Crico-thyreoideus 

 Cricoid cartilage 





Structure. — The upper head of the muscle consists of scattered fibres which blend with the oppo- 

 site muscle across the middle line; the lower head is thicker, and follows the curve of the posterior 

 border of the palate. The two heads with the fasciculus from the auditory (I'^ustachian) tube 

 form a f;ompac:t muscular band in the posterior palatine arch; the fibres mingle with those of 

 the stylo-pharyngeus, at the lower border of the superior constrictor, and then expand upon the 

 lower part of the jiliarynx. Nerves up ply. — From tlic pharyngeal ))ran('.h (jjIcxus) of the vagus. 

 Action. — (Ij y\pi)roximates the jjoslerior arches of llic I'auccs; (2) (h'prcsses the soft i)alate; 

 (3) elevates t lie piiuryiix and larynx. (Tlie origin and insertion above given are often described 

 as reversed.) 



The inferior constrictor is thick and strong. It arises from the thyreoid cartilage im- 

 mediately beliind the oblique line and superior tubercle (thyreo-pharyngeus), and from a 

 tcndincjus arch extending between the inferior tubercle of the tliyrpoi<l and the cricoid cartilage 

 and also from the lateral surface of the cricoid cartilage (cricropharyngeus) (fig. 894). The 

 fibres spread backward and medialward, the lowc^st horizontally, whilst those above ascend 

 more and more oblifiuely, and are inserted into the fibrous raph6 of the i)harynx. Some of 



