Nasal Bones
The nasal bones are two small oblong bones, varying in size and form in different individuals; they are placed side by side between the frontal processes of the maxillae and form their junction, ' the bridge' of the nose (figs. 314, 376).
Figure 376
Each nasal bone has two surfaces and four borders. The external surface (fig. 377) is concavo-convex from above downwards, and convex from side to side ; it is covered by the procerus muscle and compressor naris muscle, and is perforated near its centre by a foramen for the transmission of a small vein. The internal surface (fig. 378) is concave from side to side and is traversed from above downwards by a groove, which lodges the anterior ethmoidal nerve. The superior border, thick and serrated, articulates with the nasal notch of the frontal bone. The inferior border, thin and notched, gives attachment to the lateral cartilage of the nose. The lateral border articulates with the frontal process of the maxilla. The medial border, thicker above than below, articulates with the opposite nasal bone and is prolonged behind into a vertical crest, which forms a small part of the septum of the nose, and articulates, from above downwards, with the nasal spine of the frontal, the perpendicular plate of the ethmoid, and the cartilage of the septum of the nose.
Ossification.- The nasal hone is ossified from one centre, which appears at the beginning of the third month of fetal life in the membrane overlying the anterior part of the cartilaginous nasal capsule.
Figures 377 - 378
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Vertebral Column