342 



THE PHARYNX. 



during the passage of the food completely separates an upper from a 

 lower part by means of the contraction of the muscles connected with it 

 which are placed in the posterior pillars of the fauces. Seven openings 

 lead into the cavity of the pharynx ; viz., above the velum, the two 

 posterior openings of the nares {choaiuc narimn, fig. 241, 1), and at 

 the sides the apertures of the Eustachian tubes (6) ; while below the 

 velum, there is first the passage leading from the mouth (3) ; then 

 the superior opening of the larynx (4), and lastly the passage into the 

 oesophagus (5). 



The pharynx is about four inches and a half in length, and is con- 

 siderably 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 this it rapidly contracts like a funnel towards 

 its termination in the gullet, opposite the cricoid cartilage, where it is 

 narrowest. 



Fk. 211. 



Fig. 241. — Antero-Posterior Vertical Section through the Head a little to the 



LEFT OF the MiUDLE LiNE, SHOWING THE RELATIONS OF THE NaSAL AND BuCCAL 



Cavities, the Pharynx, Larynx, &c. 



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

 palate ; d, the lips ; it, the u\'nla ; r, anterior pillar of the fauces ; i, jjosterior pillar ; 

 t, the tonsil placed between the pillars ; p, upper part of the pharynx ; If, 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 isthiniis- 

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

 6, opening of the right Eustachian tube. 



Attachments. — The walls of the pharynx are formed by a fascia or 

 layer of fibrous tissue, named the pharyngeal aponeurosis, dense at Its, 

 upper part but lax and weak below, which is surrounded by muscles 

 and lined by a mucous membrane. At its upper end this fibrous wall 

 is attached to the posterior part of the body of the sphenoid bone. 



