THE HEAD AND NECK. 115 



membrane frequently give way, and hemorrhage results. This occurs more fre- 

 quently in children than in adults. 



Describe the nerve-supply to the mucous membrane of the nose. 



1. The olfactory nerves are distributed to the Schneiderian membrane of the 

 upper third of the septum, and to the superior and middle turbinals. 



2. The nasal nerve, a branch of the ophthalmic division of the fifth nerve, 

 supplies the anterior half of the roof, outer wall, and inner wall of the nasal 

 fossae with common sensation. 



3. The upper branches of Meckel's ganglion and the Vidian nerve supply 

 the posterior half of the roof, outer wall and inner wall, and the superior tur- 

 binal. 



4. The anterior palatine branch of Meckel's ganglion on its way down to the 

 roof of the mouth supplies the middle and inferior turbinals. 



Frontal sinus 



Orifice of middle ethmoidal cells 



SUPERIOR TURBINAL BONE 

 Orifice of the posterior ethmoidal cells 

 Orifice of the sphenoidal sinus 

 Sphenoidal sinus 



Orifloe of frontal sinus 



UPPER ORIFICE OF 

 NASAL DUCT 



ORIFICE OF EUSTAOHIAN 

 TUBE 



LOVvER ORIFICE OF NASAL DUCT 



MIDDLE TURBINAL BONE 



INFERIOR TURBINAL BONE ORIFICE OF THE ANTRUM ORIFICE OF INFUNDIBULUM 



FIG. 77. SECTION OF THE NOSE, SHOWING THE TURBINAL BONES AND MEATUSES, 

 WITH THE OPENINGS IN DOTTED OUTLINE. 



5. The naso-palatine branch of Meckel's ganglion supplies the lower and 

 posterior part of the septum. The anterior superior dental nerves supply the 

 inferior turbinated bone, hence a disease of this bone may cause pain in the ear 

 or in any of the teeth. 



The Intramural Sinuses. This is a convenient term by which to distinguish 

 the air-containing cells, in connection with some of the bones of the skull and face, 

 from the dural sinuses in the dura mater, whose use is to contain and convey blood 

 away from the brain. These sinuses are the ethmoid, the sphenoidal, the mastoid, 

 the maxillary or antrum of Highmore, the frontal, mastoid antrum, and mastoid 

 cells. As they all communicate directly or indirectly with the nasal fossae, we 

 will consider them in this place. The mastoid cells communicate with the middle 

 ear, and this with the pharynx by the Eustachian tube. The others communi- 

 cate with the nasal fossae as indicated in figure 77. 



Formation. The intramural cells are formed by absorption of the middle 





