Bones of the Skull. 



Crista ethmoidalis 



Processus orbitalis 



Incisura sphenopalatina 

 Processus sphenoidalis 



Pars 

 " perpendiciilaris 



Crista conchalis 

 Facies nasalis 



Area for completion of 

 the fossa pterygoidea 



Processus pyramidalis 

 Spina nasalis posterior 



A 



Maxilla 



Fars lioriy.oiilalis 



37. Right palate bone, os palatinum, from within. 



The paired os palatinum (palate bone) (see also Figs. 38, 39, 59, 60, 68 70, 7274) 

 lies in the posterior part of the nasal cavity and there forms a part of the floor of the same 

 (of the hard palate) and of the lateral wall. It presents for examination a pars horizontals 

 and a pars perpendicularis. 



The pars horizontalis (0. T. horizontal plate) (see also Figs. 38, 59, 60 and 7375) 

 is very similar to the proc. palatinus maxillae, only shorter; the upper surface (fades nasalis), 

 is smooth and slightly concave; the lower surface (fades palatina), is somewhat rough and 

 presents near the posterior margin a small sickle-shaped elevated surface for the attachment 

 of the m. tensor veli palatini. The anterior, slightly serrated margin lies on the posterior 

 border of the proc. palatinus maxillae and forms with this the sutura palatina transversa. 

 The medial margin unites with the corresponding border of the bone of the other side and 

 forms the posterior part of the sutura palatina mcdiana ; on the upper surface of this border 

 the crista nasalis (for union with the vomer) projects upward and runs out behind into the 

 spina nasalis posterior. The posterior margin is smooth and concave. 



From the lateral part of the posterior margin projects backward the strong processes 

 pyramidalis (see also Figs. 38, 39, 59, 60, 67 and 68). It is inserted from in front into the 

 fissura pterygoidea oss. sphenoidalis and helps, with a smooth area on its posterior surface, 

 to complete the inferior part of the fossa pterygoidea. The external, rough surface unites 

 with the posterior portion of the corpus maxillae just above the eighth alveolus. The edge 

 between the posterior and the lateral surface sometimes helps, also to form the fossa infra- 

 temporalis (see Figs. 68), and then possesses a smooth surface. The medial, smooth surface 

 looks into the nasal cavity. The inferior surface belongs to the lower surface of the hard 

 palate and contains usually three openings, of which the foramen palatinum majus lies 

 furthest forward, the others, foramina palatina minor a, lie further backward. These are the 

 outlets of the canales palatini (for the aa. palatinae major et minores ; nn. palatini) which 

 sometimes open lateralward and which perforate perpendicularly the processus pyramidalis: 

 they are the starting points of the sulci palatmi on the hard palate (see p. 29). 



