THE PALATE BONES. 23 



Name its articulations, centres, and muscles. The malar articulate* 

 with 4 bones, the frontal, sphenoid, temporal, and superior maxillary. It is 

 developed by one centre of ossification, and has 5 muscles attached to it, the 

 levator labii superioris, zygomaticus major and minor, masseter and temporal. 



THE PALATE BONES. 



Describe them. They are 2. irregularly-shaped bones, situated poste- 

 riorly in the nares. Each bone assists in forming the floor and outer wall of 

 the nose, the roof of the mouth, the floor of the orbit, the inner wall of the 

 antrum, the zygomatic, spheno-maxillary, and pterygoid fossae, and presents ths 

 following points. 



HORIZONTAL PLATE, completes the nasal floor and hard palate ; has a 

 Ridge, on the inferior surface, for the tensor palati aponeurosis. 

 Groove, assisting to form the posterior palatine canal. 

 Foramina, transmitting the anterior and posterior FIG. 8. 



palatine nerves. 

 Anterior Border^ is serrated, and joins the superior 



maxillary bones. 



Posterior Border, is free and concave, for the attach- 

 ment of the soft palate. 



Inner Border, d is thick, and articulates with its fel- 

 low, forming a groove for the reception of the vomer. 

 Its posterior extremity is the 

 Posterior Nasal Spine, for the origin of the azygos 



uvulae muscle. 



VERTICAL PLATE/ a broad and thick lamella, presents the following : 

 Superior Turbinated Crest, on the inner surface. Below it is the 

 Inferior Turbinated Crest,g dividing the middle meatus of the nose from 



the inferior, and articulating with the inferior turbinated bone. 

 Posterior Border, articulates with the pterygoid process of the sphenoid. 

 Groove, on the external surface, helping to form the posterior palatine canal. 

 Two Smooth Surfaces, externally, one forming the inner wall of the zygo- 

 matic fossa; the other, part of the inner wall of the antrum. 

 Two Rough Surfaces, also externally, one for articulation with the superior 



maxillary ; the other with the pterygoid process of the sphenoid. 

 Deep Notch, which by articulation with the sphenoid bone, forms the 



spheno-palatine for amen, h for the spheno-palatine nerves. 

 PTERYGOID PROCESS,^ is wedged into the notch between the plates of the ptery- 

 goid process of the sphenoid, with which it articulates laterally. In it are the 

 Palatine Foramina, for the external and posterior palatine nerves. 

 Posterior Surface, aids in forming the pterygoid fossa. 

 8 



