Bones of the Skull. 



31 



Proccssus orbitpli? 



Incisura sphenopalatina 

 Processus sphenoidalis 



Crista conchalis 



Crista nasalis s 



Facies nasalis 



Sulcus pterygopalatinus 



Pars 

 perpendicularis 



Processus sphenoidalis 



Incisura sphenopalatina 



Processus orbitalis 



Facies maxillaris 



Sulcus 

 pterygopalatinus 



Spina nasalis posterior 



Area completing 



the fossa 



pterygoidea 



Pars horizoiitalis 



Processus pyramidalis 



Foramen palatinum majus 



i ' 



Processus pyramidalis 

 Area completing the fossa pterygoidea 



38 and 39. Right palate bone, os palatinum. 



From behind. From without. 



The pars perpendicularis (0. T. vertical plate] (see also Figs. 37, 6870 and 

 72 74) ascends as a thin leaf of bone vertically upward from the lateral margin of the pars 

 horizontals. The medial fades nasalis is smooth and presents two ridges extending from 

 before backward, an upper, shorter, crista ethmoidalis (0. T. superior turbinated crest), for 

 the attachment of posterior, free end the concha nasalis media, and a lower, crista conchalis 

 (0. T. inferior turbinated crest), for union with the concha nasalis inferior. The lateral surface, 

 fades maxillaris, is for the most part rough and unites in front with the posterior, rough 

 portion of the facies nasalis corporis maxillae, so that it covers over a portion of the hiatus 

 maxillaris from behind (see Fig. 68); it is attached behind to the anterior margin and the 

 medial surface of the lamina medialis proc. pterygoidei oss. sphenoidalis. Between these two 

 areas, extending from above downwards, is the smooth, shallow sulcus pterygopalatinus. 

 Through the attachment of the lateral surface to the two bones mentioned this forms together 

 with the sulcus pterygopalat. of the proc. pteiyg. oss. sphenoidalis and a groove on the upper 

 jaw bone, above, the fossa ptcrygopalatina, open lateralward (for the aa. maxill. int., palat. 

 descendens, sphenopalat. ; nn. zygornat., sphenopalat. , alveol. sup., infraorbit. ; gangl. spheno- 

 palat.), below, the canalis pterygopalatinus (0. T. posterior palatine canal) (for the a. palat. 

 descendens; nn. palat., rr. nasal, post. inf. gangl. sphenopalat.), closed also externally by the 

 proc. pterygoideus oss. sphenoid, and the upper jaw; it is continued below into the canales 

 palatini (for the aa. palatinae major et minores; nn. palat.) which usually run in the proc. 

 pyramidalis alone. From the upper margin of the pars perpendicularis extend two processes, 

 the processus sphenoidalis bent somewhat backward and markedly medianward, which lies 

 on the inferior surface of the body of the sphenoid and on the ala vomeris, and the processus 

 orbitalis forward and somewhat lateralward. The latter is bulged out and contains a small 

 cavity, the posterior part of a posterior ethmoidal cell which projects into the proc. orbitalis. 

 Its lateral, upper, smooth surface forms the most posterior part of the floor of the orbit: in 

 front and below it meets the facies orbitalis corporis maxillae (sutura palatomaxiUaris) , 

 in front and above the lamina papyracea oss. ethmoid, (sutura palatoethmoidalis) , behind, 

 and above the anterior margin of the lateral surface of the body of the sphenoid (sutura 

 sphenoorbitalis) ; behind and below it lies free and helps in part to form the medial portion 

 of the fissura orbitalis inferior, in part it looks into the fossa pterygopalatina. Between the 

 proc. sphenoid, and the proc. orbital, lies the indsura sphenopalatina, which is closed by the 

 attachment of the bone to the under surface of the body of the sphenoid forming the foramen 

 sphenopalatinum (for the a. sphenopalat. : rr. nasal, poster, super, lateral et medial, gangl. 

 sphenopalat.). 



