THE BONES. 



69 



Figure : ring-shaped. Parts : Body, Arches, Processes ; 1 Spi- 

 nous, 2 Transverse, 4 Articular. 



Connection; the 1st cervical vertebra with the skull, and with 

 the 2d cervical vertebra, the 2d with the 3d, and so forth ; the 

 5th Lumbar vertebra with the Sacrum ; the 12 Dorsal, besides, 

 with the ribs. 



Position : one above the other. 



a. Body, corpus, centrum, is the anterior, thickest, and most essential part of a 

 vertebra; it presents above and below slightly concave surfaces covered with 

 cartilage, for its junction with the vertebral body lying above and below it, 

 is anteriorly convex; on the sides, evenly excavated and grooved; behind, 

 concave and perforated by foramina, for vessels. This posterior surface forms 

 with the 



b. Arch, arcus [neural arch (Owen)], which springs from its posterior lateral 

 parts, the vertebral foramen, foram. spinale s. medullare, which is triangular in 

 almost all Vertebrae, and serves as a passage for the spinal marrow. The 

 notches, incisura, on the superior and inferior borders of every arch, form, the 

 two together, an inter vertebral foramen, foram. intervertebrale, for art. and nerv. 

 spinal, upon each side. 



c. Processes, proccssus, seven in number. 



1. Muscular processes, proc. musculares, three to each vertebra; 



a. Processes Spinosus, one Spinal process [Neural spine, (Owen)], behind in 

 the centre of the arch; its root almost forked; its point, apex, freely projecting 

 into the back, for the lig. interspinos. apicum, and the Extensor muscles of the 

 trunk. 



b. Processus transversi, two transverse processes, horizontal, one on each 

 side between the body and arch projecting outwards, for li.g. intertransversalia,- 

 and the obliquely ascending or descending cervical and dorsal muscles. 



2. Articular processes, proc. articulares s. obligui,two superior, two inferior, 

 spring laterally from the arch, behind the transverse processes, project out 

 above the plane of the vertebral body ; are tipped with cartilage, and associated, 

 the two of the one, with the two of the other vertebra. 



76. Differences between the Vertebrae of the three regions. 



