62 ANATOMY OF THE HEAD AND NECK 





the petrous portion of the temporal bone, and inferiorly 

 losing itself in the muscular strata of the pharynx. 



The pharynx is now to be laid tfpen along the posterior median 

 line ; it is also to be dissected away, for a short distance on each side, 

 from its aponeurotic attachment to the occipital bone. 



The pharynx terminates in the oesophagus by a constric- 

 tion opposite the cricoid cartilage. The mucous membrane 

 of the pharynx is thicker, redder, and more abundantly sup- 

 plied with muciparous glands than that of the oesophagus. 



The (ESOPHAGUS lies upon the bodies of the vertebne 

 behind the trachea, and, with two or three slight lateral 

 curvatures, extends downward about nine inches to termi- 

 nate in the stomach. Its walls, like those of the alimentary 

 canal elsewhere, are composed of three layers, viz., muscular, 

 cellular, and mucous. The muscular coat consists of longi- 

 tudinal and circular fibres; these are red and well marked 

 near the pharynx, but pale and indistinct as they approach 

 the stomach. At the upper part, the longitudinal fibres, 

 which are external, are arranged in three fasciculi, one ante- 

 rior, arising from the cricoid cartilage, and two lateral, con- 

 tinuous with the inferior constrictor muscle of the pharynx. 

 The circular, or internal fibres, are also continuous with 

 those of the inferior constrictor. The mucous coat is very 

 movable, and when not distended is thrown into longitu- 

 dinal folds, so that the sides of the tube come in contact 

 with each other. 



The section of the pharynx exposes the posterior aper- 

 tures of the nasal cavity, divided by the septum nasi. On 

 each side of this will be found the trumpet-shaped orifice 

 of the Eustachian tube ; if the mucous membrane is re- 

 moved, it will be found that this tube is composed of carti- 

 lage, and is nearly an inch in length ; it is attached supe- 

 riorly to a groove between the sphenoid and the petrous 

 portion of the temporal bone, through which it communi- 

 cates with the cavity of the tympanum. A bundle of 

 muscular fibres, extending from the lower border of the 

 Eustachian tube to the palato-pharyngeus muscle, is called 

 the salpingo-pharyngeus muscle ; it does not always exist. 



PALATINE REGION. 



The ISTHMUS FAUCIUM is the constriction between the 

 mouth and the upper part of the pharynx, formed above 

 \)y the soft palate, and below by the tongue. 



