so 



THE SKELETON 



bone, and the inner surfaeoof the internal i.terytroid plate. The outer wall presents 

 three recesses or meatuses. The superior meatus, the shortest, is situated between 

 the superior and middle turbinal; it opens ]K)steriorly; two orifices are in relation 

 with it, namely, the orifice of the posterior ethmoidal cells and the spheno- 

 palatine foramen. The middle meatus lies between the middle and inferior 

 turbinals. It oi)ens anteriorly and posteriorly. This meatus has two orifices com- 

 numieating with it — the opening of the antrum (which is of very irregular shape) 

 and the termination of the infundibulum. The inferior meatus is situated be- 

 twei-n the inferior turl)inal and the lloor of the fossa; it i)resents near its anterior 

 part, under cover of the turbinal, the terminal orifice of the nasal duct. This is 

 the largest meatus, and, like the middle, opens anteriorly and posteriorly. 



The anterior narial orifices are bounded above by the lower border of the nasal 

 bones, laterally l)y the maxilhe, and inferiorly by the premaxillary portions of the 

 maxillie. In the recent state they are separated l)y the triangular cartilage; in the 

 dried skull the most anterior inferior limit is the anterior nasal spine. 



The posterior narial orifices are bounded above by the al?e of the vomer, the 

 sphenoidal process of the palate bones, and the under surface of the sphenoid; 

 externally by the internal pterygoid plates; and inferiorly by the posterior border 



Fig. 88. — Skotion thbough the Nasal Fossa to show the Outer Wall with 



THE Meatuses. 



CRISTA GALLI 





BODY OF SPHENOID 



SPHENOIDAL SINUS 



SPHENO-PALATINE FORAMEN 



MIDDLE MEATUS 



INTERNAL PTERYGOID PLATE 



PALATE BONE <Y I '^ 



FRONTAL SINUS 



SUPERIOR TURBINAL 

 '— MIDDLE TURBINAL 

 NFUNDIBULUM 



INFERIOR TURBINAL 

 ANTERIOR NASAL SPINE 



ANTERIOR PALATINE FORAMEN 



of the horizontal ]»la.tes of the palate bones. They are divided by the posterior 

 border of the vomer and the posterior nasal spine. 



The nasal fossa communicate with all the more important fossae and sinuses of 

 the skull. By means of the foramina in the roof they are in connection with the 

 cranial cavity. The infundibulum brings each fossa in communication with the 

 frontal and anterior ethmoidal cells. The posterior ethmoidal and the sphenoidal 

 cells open into the superior meatuses. The spheno-palatine foramina connect them 

 witli the splieno-maxillary fossffi, and an irregular orifice in each outer wall causes 

 them to comnmni(-ate with the antra. The nasal ducts connect them with the 

 orbits, and the anterior palatine canals with the buccal cavity. 



The sutures visible in an anterior view of the skull are numerous, and for the 

 most part uiiiiii]»ortant: — 



The transverse suture extends from one external angular process to the other. 

 The upper part of the suture is formed by the frontal bone; below are the malar, 

 greater and lesser wings of the sphenoid, os planum, lachrymal, maxillary, and 

 nasal bones. A i)ortion of this complex suture, lying between the si)henoidril and 

 frontal bones, a])pears in the anterior cranial fossa. 



Other and less important fissures are the internasal, naso-maxillary, inter- 



