60 OSTEOLOGY, OR ANATOMY OF OSSEOUS SYSTEM 



The Nasal Bones 



The two form the bridge of the nose, and each articulates 

 with four bones the frontal, superior maxillary, ethmoid, 

 and its fellow. They are narrow and thick above, broader 

 and thinner below. They articulate above with the inner 

 part of the nasal notch of the frontal. 



The inferior border is free, and gives attachment to the 

 lateral nasal cartilage; it usually has a small notch near the 

 inner end. The external border is longest, and articulates 

 by means of small teeth with the nasal process of the superior 

 maxilla. 



The internal border meets its fellow- in a somewhat irregular 

 internasal suture, which commonly deviates to one side at 

 the upper end. Posteriorly the two form a crest which rests 

 from above down on the nasal process of the frontal, the ver- 

 tical plate of the ethmoid, and the septal nasal cartilage. The 

 facial surface is convex below and concave above, and presents 

 vascular foramina. 



The posterior surface is concave, and a little external to 

 its centre is a longitudinal groove for the nasal nerve. 



The Lacrymal Bones 



The lacryrnal, or os luif/uis, is a thin scale, like a finger 

 nail, at the anterior and inner part of the orbit. It articulates 

 with four bones frontal, ethmoid, superior maxilla, and 

 inferior turbinate. It presents two surfaces and four borders. 

 Its e.tierndl xmjdcc is divided by a vertical ridge, the lacrymal 

 crest; in front of it is the lacrymal groove, and this part is 

 prolonged below as the descending process to articulate with the 

 inferior turbinate; behind the crest the surface is smooth and 

 forms part of the orbit, and is produced below into the hamidar 

 process, which comes forward into the lacrymal notch of 

 the superior maxilla and bounds the outer side of the orifice 

 of the nasal duct. The internal surf (tee is a depressed furrow 

 completing above some of the anterior ethmoidal cells, and 

 below it looks into the middle nasal meatus. 



Of the four borders, the anterior is the longest and articulates 

 with the nasal process of the superior maxillary bone. 



