THE HEAD AND NECK. 



IT 3 



posterior nares is the opening into the pharynx. (Fig. 73.) Notice: On the 

 outer wall, and even forming part of the same, are the three turbinated bones. 



Study figure 74. Remove the mucous membrane from the septum, and find 

 (i) suture between the vomer and ethmoid ; (2) junction between cartilage and 

 ethmoid ; (3) the naso-palatinc groove on the vomer, containing a nerve and an 

 artery of the same name. The nerve, a branch of Meckel's ganglion, one on each 

 side, passes through the foramina of Scarpa, in the anterior palatine canal (Fig. 

 74), and anastomoses with the anterior palatine nerves, also branches of Meckel's 

 ganglion. (Figs. 53 and 75.) 



The turbinated bones (Fig. 77) are three in number. They occupy the outer 

 wall, as follows fractionally : The superior turbinal, the posterior third ; the middle 

 turbinated, the posterior two-thirds ; the inferior turbinated extends the whole 

 length of the wall. 



NA SA L OLFA CTOR Y 

 FRONTAL SINUS NERVE NERVE 



OLFACTORY NERVE 

 TO SUPERIOR TL'R- 

 JilNA TE BONE 



SPHENOIDAL SINUS 



VIDIAN NERVE 



MECKEL'S 



GANGLION 

 DESCENDING 



PALATINE 



ORIFICE OF EUSTACHIAN 

 TUBE 



NASAL BRANCHES 



POSTERIOR 



PALATINE 

 ANTERIOR 



PA LA TINE 

 MIDDLE PALATINE 



FIG. 75. NERVES OF THE NASAL CAVITY. 



Tlie Etluno-turbinals (Fig. 77). This name is given to the superior and middle 

 turbinals. They belong to the lateral mass of the ethmoid bone. 



The meatuses are three irregular cavities on the outer wall of the nasal 

 fossae. Into them open the nasal duct and the frontal, ethmoidal, maxillary, and 

 sphenoidal sinuses : 



Inferior, receives the nasal duct conveying the tears. 



Middle, receives the openings the antrum, frontal, and anterior ethmoidal cells. 



Superior, the opening of the sphenoidal and posterior ethmoidal cells. 



Describe the nasal mucous membrane. 



It is called pituitary membrane, from an erroneous idea entertained by the 

 ancients that the nasal deflections had their origin in the pituitary body. It is 

 also called the Schneiderian mucous membrane. In the regions of the turbinals 

 and septum it is thick, vascular, and loosely attached to the bone ; in the bottom 

 of the meatuses and in the intramural sinuses communicating with the nasal 



