THE PHARYNX. 951 



lie ascertained by driving a needle through the tissues of the palate in this situation, when it 

 will be at once felt to enter the canal. The artery emerging from the opening runs forward in a 

 groove in the bone just internal to the alveolar border of the hard palate, and may be wounded 

 in the operation for the cure of cleft palate. Under these circumstances the palatine canal may 

 require plugging. By introducing the finger into the mouth the anterior border of the coronoid 

 process of the jaw can be felt, and is especially prominent when the jaw is dislocated. By 

 throwing the head well back a considerable portion of the posterior wall of the pharynx may be 

 seen throush the isthmus faucium, and on introducing the finger the anterior surface of the 

 bodies of the upper cervical vertebrae may be felt immediately beneath the thin muscular stra- 

 tum forming the wall of the pharynx. The finger can be hooked around the posterior border 

 of the soft palate, and by turning it forward the posterior nares, separated by the septum, can 

 be felt, or the presence of any adenoid or other growths in the naso-pharynx ascertained. 



THE PHARYNX. 



The pharynx is that part of the alimentary canal which is placed behind the 

 nose, mouth, and larynx. It is a musculo-membranous sac, somewhat conical in 

 form, with the base upward and the apex downward, extending from the under 

 surface of the skull to the cricoid cartilage in front and the intervertebral disk 

 between the fifth and sixth cervical vertebne behind. 



The pharynx is about four inches and a half in length, and broader in the 

 transverse than in the autero-posterior diameter. Its greatest breadth is opposite 

 the cornua of the hyoid bone ; its narrowest point, at its termination in the 

 oesophagus. It is limited, above, by the body of the sphenoid and basilar process 

 of the occipital bone ; belotv, it is continuous with the oesophagus ; posteriorly, it 

 is connected by loose areolar tissue with the cervical portion of the vertebral 

 column and the Longi colli and Recti capitis antici muscles ; anteriorly, it is 

 incomplete, and is attached in succession to the internal pterygoid plate, the 

 pterygo-maxillary ligament, the lower jaw, the tongue, hyoid bone, and thyroid and 

 cricoid cartilages ; lateral!//, it is connected to the styloid processes and their mus- 

 cles, and is in contact with the common and internal carotid arteries, the internal 

 jugular veins, and the glosso-pharyngeal, pneumogastric, hypoglossal, and sym- 

 pathetic nerves, and above with a small part of the Internal pterygoid muscles. 



It has seven openings communicating with it the two posterior nares, the 

 two Eustachian tubes, the mouth, larynx, and oesophagus. 



The posterior nares are the two oval openings (see page 222) situated at the 

 upper part of the anterior wall of the pharynx. 



The two Eustachian tubes open one at each side of the upper part of the 

 pharynx, at the back part of the inferior meatus. Below the posterior nares are 

 the posterior surface of the soft palate and uvula, the large aperture of the 

 mouth, the base of the tongue, the epiglottis, and the cordiform opening of the 

 larynx. 



The cewphageal opening is the lower contracted portion of the pharynx. 



Structure. The pharynx is composed of three coats mucous, fibrous, and 

 muscular. 



The pharyngeal aponeurosis, or fibrous coat, is situated between the mucous 

 and muscular layers. It is thick above, where the muscular fibres are wanting, and 

 is firmly connected to the basilar process of the occipital and petrous portion of the 

 temporal bones. As it descends it diminishes in thickness, and is gradually lost. 

 It is strengthened posteriorly by a strong fibrous band which is attached above to 

 the pharyngeal spine on the under surface of the basilar portion of the occipital 

 bone, and passes downward, forming a median raphe, which gives attachment to 

 the Constrictor muscles of the pharynx. 



The mucous coat is continuous with that lining the Eustachian tubes, the nares, 

 the mouth, and the larynx. It is covered by columnar ciliated epithelium, as low 

 down as on a level with the floor of the nares ; below that point the epithelium is of 

 the squamous variety. Beneath the mucous membrane are found racemose mucous 

 glands ; they are especially numerous at the upper part of the pharynx around the 

 orifices of the Eustachian tubes. Throughout the pharynx are also numerous crvpts 

 or recesses, the walls of which are surrounded by lymphoid tissue similar to what 



