820 



THE PHARYNX. 



to the sides of the tongue, to the hyoid bone, and stylo-hyoid ligament ; 

 and, still lower down, to the thyroid and cricoid cartilages. 



The pharynx is about four iuches and a half in length, and is considerably 

 wider across than it is deep from before backwards. Its width above is 

 moderate ; its widest part is opposite the cornua of the hyoid bone, and 

 below tbis it rapidly contracts towards its termination, opposite the cricoid 

 cartilage, where it is narrowest. 



Structure. The muscles of the pharynx are the superior, middle and 

 inferior constrictors, the stylo-pharyngeus, and the palato-pharyngeus. 

 They are described at page 187. 



The mucous membrane lining the inner surface of the pharynx is con- 

 tinuous at the several apertures with that of the adjacent cavities. It 

 varies somewhat in its character in different parts. Its upper portion is 



Fig. 575. 





Fig. 575. ANTERO-POSTERIOR VERTICAL SECTION THROUGH THE HEAD A LITTLE TO THE 



LEFT OP THE MlDDLE LlNE, SHOWING THE RELATIONS OP THE NASAL AND BuCCAL 



CAVITIES, THE PHARYNX, LARYNX, &c. 



a, nasal septum, and below it the section of the hard palate ; b, the tongue ; c, soft 

 palate ; d, the lips ; u, the uvula ; r, anterior pillar of the fauces ; i, posterior pillar ; 

 t, the tonsil placed between the pillars ; p, upper part of the pharynx ; h, body of the 

 hyoid bone ; k, thyroid cartilage ; n, cricoid cartilage ; v, on the upper vocal cords above 

 the glottis ; s, epiglottis ; 1, posterior opening of the nares ; 3, behind the isthmus 

 faucium ; 4, opposite the superior opening of the larynx ; 5, passage into the oesophagus ; 

 6, opening of the right Eustachian tube. 



thick where it adheres to the periosteum of the basilar process, but is much 

 thinner near the entrance of the Eustachian tube and the posterior nares : 

 in this situation numerous glands are found collected in a layer beneath the 

 mucous membrane. The glands are of two kinds, viz., racemose, which are 

 especially numerous in the upper portion ; and simple or compound follicular, 

 which exist throughout the whole of the pharynx. A chain of glands forming 

 a glandular mass, exactly similar to that of the tonsils, stretches across the 



