ANATOMY IX A NUTSHELL. 547 



The inferior border, which is the longest, articulates with the nasal cresl 

 of the superior maxillary and palate bone. 



The anterior border is short and articulates with the incisor crests of the 

 superior maxillary bone. 



The antero-superior border receives the Lower margin of the triangular 

 cartilage below and the vertical plate of the ethmoid above. 



The postero-superior border is the thickest and has a median groove which 

 receives the rostrum of the sphenoid bone. This border is bounded on either 

 side by the ala, which fits in the vaginal process of the sphenoid. This joint 

 is a schindylesis. 



OSSIFICATION. — This bone ossifies from one center. 



Articulation. — It articulates with six bones. The sphenoid and ethmoid 

 of the cranium, the two superior maxillary, the two palate of the face. It also 

 articulates with the cartilage of the septum. 



Attachment of Muscles. — It has no muscles attached to it. 



Blood Supply. — Anterior and posterior ethmoidal, and nasopalatine 

 through Stenson's canal. 



LESSON CLXXXVI. 



Palate Bone. (Plates CCLXII-CCLXIII-CCXXVIII-CCXXIX). 



The palate bones are two in number and situated between the superior 

 maxillary bones and the pterygoid processes of the sphenoid bone at the back 

 of the nasal fossae. Each bone helps to form the roof, floor, and outer wall of 

 the nose, and the floor of the orbit. They also help to form the spheno-max- 

 illary fissure, spheno-maxillary fossa, and the pterygoid fossa, and the zygo- 

 matic fossae. Each one has the following points for consideration: 



The horizontal plate, which is thick, has two surfaces and four borders. 



The superior surface is concave transversely and forms the back part of 

 the floor of the nose. 



The inferior surface is also concave and forms the back pail of the hard 

 palate, and has upon it a transverse ridge for the attachment of the Tensor 

 tympani aponeurosis. A groove is situated at the outer end of this transverse 

 ridge which with the tuberosity of the superior maxillary bone forms the pos 

 terior palatine canal. Posterior to this groove are foramina of the accessory 

 posterior palatine canals. 



The anterior border is serrated ami articulates with the palate process of 

 the superior maxillary bone. 



The internal border is thick and articulate- with the internal border of it- 

 fellow, thus forming a groove on the upper surface for the reception of the 

 vomer. On the posterior extremity of this border is a posterior nasal -pine 

 which is for the origin of the Azygos uvula- muscle. 



The external border joins the verl Leal plate of the palate bone at righl angle. 



The posterior border is free and concave, and gives attachment to the soft 

 palate. 



