THE PALATE BONE. 53 



generally of large size, and open separately on the palate. A median anterior palatine fossa 

 receiving the two incisor foramina is met with only in man and a few animals, and the deeply 

 placed lamina which then bounds the incisor foramen on the inner side corresponds to the 

 mesial palatine process of the premaxillary bone of other animals. The foramina of Scarpa 

 lie in the suture between the laminae referred to. They transmit the naso-palatine nerves, the 

 nerve of the right side occupying, according to Scarpa, the posterior one, which is usually the 

 larger, and that of the left side, the anterior ; but they are very inconstant. (Scarpa, Annot. 

 Anatom., lib. ii, cap. 5.) 



The maxillary sinus or antrum of Highmore has an irregularly pyramidal form. 

 Its ^alls are thin : the sides correspond to the facial, zygomatic and orbital surfaces 

 of the body ; the base to the nasal surface ; and the apex extends into the malar 

 process. The large aperture is closed to a considerable extent by the uncinate 

 process of the ethmoid, the palate and inferior turbinate bones ; and in the fresh 

 state it is reduced by the mucous membrane to a small orifice through which the 

 cavity communicates with the middle meatus of the nose. Its extent below generally 

 corresponds with that of the molar teeth, and the outer alveoli of one or more of 

 these form prominences in its floor. 



THE PALATE BONE. 



The palate bone forms the back part of the hard palate and the lateral wall 

 of the nose between the superior maxillary bone and the internal pterygoid plate. 

 It consists of a horizontal and a vertical plate united at a right angle, and of 

 three processes, viz., the tuberosity or 



pyramidal process, extending outwards ORBITAL PROCESS 



and backwards from the junction of 

 the horizontal and vertical plates, and 

 the orlital and splwiwidal processes, 

 surmounting the vertical plate. 



The palate bone articulates with its 

 fellow, and with the superior maxillary, 

 ethmoid, sphenoid, vomer, and inferior >NF. T URB. 



turbinate bones. NASAL CREST 



The horizontal or palate plate pre- 

 sents a superior surface, concave and 

 smooth, forming the back part of the 

 floor of the nasal fossa, and an inferior 

 surface, completing the vault of the hard 

 palate, and marked near its posterior Fig 53i _ ElGHT PALATE BONE> FROM BEHIND . 

 border by a transverse ridge to which (Drawn by D. Gunn. ) 



some tendinous fibres of the tensor 



palati muscle are attached. The anterior border articulates with the palate process 

 of the superior maxilla ; the posterior is free, concave and sharp, giving attach- 

 ment to the soft palate, and produced at its inner end into a sharp point, which 

 with that of the other side forms the posterior nasal or palatine spine ; internally 

 it articulates with its fellow by a thick serrated border, forming a continuation of 

 the nasal crest of the superior maxillae, and also supporting the vomer ; externally, at 

 its junction with the vertical plate, it is grooved by the extremity of the posterior 

 palatine canal. 



The vertical plate is very thin. Its internal or nasal surface is divided into two 

 parts, corresponding to the middle and inferior meatuses of the nose, by a nearly hori- 

 zontal ridge, the inferior turbinate crest, which articulates with the inferior turbinate 



PTER. PAL. CA 

 SPHEN. PAL. NOTCH 



SPHEN. MAX. FOSSA 



VERT1CAL PLATE 



EXT. PTCR. PL. 



