THE BONES OF THE HEAD 109 



The superior border is short, and articulates with the internal 

 angular process of the frontal. The inferior harder, behind the 

 lachrymal crest, articulates with the internal border of the orbital 

 surface of the superior maxilla, whilst in front of the crest it forms, 

 as stated, the descending process, and articulates with the lachrymal 

 process of the inferior turbinate. The anterior harder articulates 

 with the inner lip of the lachrymal groove on the posterior border 

 of the nasal process of the superior maxilla. The posterior harder 

 articulates with the anterior border of the os planum of the ethmoid. 



The bone derives its blood-supply from the nasaJ and anterior 

 ethmoidal branches of the ophthalmic artery. 



Articulations. — The lachrymal articulates with four bones, as 

 follows : superiorly with the frontal, anteriorly with the superior 

 maxilla, inferiorly with the inferior turbinate, and again with the 

 superior maxilla, and posteriorly with the ethmoid. 



Structure. — ^The bone consists of a thin translucent plate. 



Ossification. — The lachrymal is developed in membrane usually from one 

 centre, which appears during the third month of intra-u ferine life. 



The Inferior Turbinate Bones. 



The inferior turbinate or spongy bone (maxillo-turbinal) some- 

 times called the inferior concha, is situated on the outer wall of the 



Lachrymal Process 



1. A Ethmoidal Process 



Front Part of Superior- 

 Border 



, "-^ ^^^^^"^""--rtS^^^^ Back Part of Superior Bord<;r 



)erior -^<y>^ - " -' • ibR^ i 



Anterior ExUemity - -^^ ■' f¥*'x - ' ^ *^ ~*'J!P)'^/^ 



^'^~~^^ir^^^T~Tf'J.!^i-^'^ Inferior Border 



L Lachrymal Process 



Ethmoidal Process 1 



Maxillary Process ^ 



Anterior 



Extremity 



Inferior Border 



Fig. 67. — The Right Inferior Turbinate Bone. 

 A, Internal View ; B, External View. 



nasal fossa, where it overhangs the inferior meatus, and is in series 

 with the inferior turbinate process (middle spongy bone) of the 

 ethmoid. It is elongated from before backwards, and presents 



