no A MANUAL OP ANATOMY 



two surfaces, two borders, and two extremities. The external - 

 surface is concave, and is overhung above, over about its middle 

 third, by the maxUlary process. It looks towards the outer wall 

 of the nasal fossa. The internal surface is irregularly convex, 

 pitted, and marked by a few antero-posterior grooves. It bulges 

 into the nasal fossa, and limits interiorly the middle meatus. 



The superior border, which is attached, slopes downwards and 

 forwards in front, where it articulates with the inferior turbinate 

 crest of the superior maxilla. Behind this it presents a slight 

 concavity, limited in front by the lachrymal process, which articu- 

 lates with the descending process of the lachrymal, and forms part 

 of the lachrymal canal. Behind the concavity is the ethmoidal 

 process for the uncinate process of the ethmoid. The portion of 

 the superior border between these two processes is folded down- 

 wards and outwards into a thin plate, called the maxillary process, 

 which forms part of the inner wall of the antrum of Highmore 

 below the opening of that cavity. Behind the ethmoidal process 

 the superior border slopes downwards and backwards, and articu- 

 lates with the inferior turbinate crest of the palate bone. The 

 inferior border is convex, thick, pitted, and free. The anterior 

 extremity is short and stunted, whilst the posterior is long, slender, 

 and pointed. 



The bone receives its blood-supply from the spheno-palatine 

 branch of the internal maxillary, and anterior ethmoidal branch 

 of the ophthalmic, arteries. 



Articulations. — The inferior turbinate articulates with the follow- 

 ing four bones : superior maxilla, lachrymal, ethmoid, and palate. 



Structure. — ^The bone is light and porous. 



Ossification. — The inferior turbinate is developed in cartilage from one 

 centre, which appears in the fifth month of intra-u ferine Ufe. 



The Palate Bones. 



The palate bone enters into the formation of the hard palate, 

 the outer wall of the nasal fossa, and the floor of the orbit. It 

 consists of a horizontal and perpendicular plate, which meet at a 

 right angle, and of three processes, namely, pyramidal process 

 or tuberosity, situated at the meeting of the two plates posteriorly, 

 and orbital and sphenoidal processes, situated at the upper ex- 

 tremity of the perpendicular plate, where they are separated by 

 the spheno-palatine notch. 



The horizontal or palatal plate is quadrate, and presents two 

 surfaces and four borders. The superior or nasal surface is smooth 

 and concave from side to side. It forms the posterior fourth of the 

 floor of the nasal fossa, and is covered in the recent state by the nasal 

 mucous membrane. The inferior or palatal surface forms the pos- 

 terior fourth of one-half of the hard palate, and near its posterior 

 border it presents a short transverse ridge, which gives insertion to 

 a portion of the tendon of the tensor palati. The anterior border 



