76 



OSTEOLOGY 



portion, and a posterior portion, the arch or neural 

 canal. The arch is formed by two pedicles, and two 

 laminae, supporting seven processes viz., four articular, 

 two transverse, and one spinous. Taking a typical 

 vertebra the tenth thoracic, for example. The body 

 is cylindric; the upper and lower surfaces are flat, 

 with a rim around the circumference. The front 



Superior articular process. 



Demi-facet for head of rib. 



Facet for tubercle of rib. 



Demi-facet for head of rib. 

 Inferior articular process. 



A dorsal vertebra. (Gray.) 



and sides are convex from side to side and concave 

 from above downward. The back is slightly concave 

 from side to side. The neural arch is completed 

 laterally by two processes of bone arising from the 

 postero-external aspect of the body, called pedicles, 

 and the latter continue as lamina behind, where 

 they meet to complete the posterior aspect of the neural 

 arch. The upper and lower borders of the pedicles 



