The true vertebra - Lumbar vertebra
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Lumbar vertebra
The lumbar vertebras, (fig. 36,) five in number, are larger than either of the other sets. The foramen of each vertebra in this region is large and triangular. The notches, 3 * for the formation of the inter-vertebral foramina are very deep, especially the inferior pair. The body, 1 much broader from side to side than from before backwards, is flat on its superior and inferior surfaces. It is not so convex anteriorly as that of the dorsal vertebras. The articulating processes are thick, strong, and disposed vertically; the superior pair, 7 concave, look backwards and inwards; the inferior, 8 convex, forwards and outwards; the former are farther apart than the latter, hence they receive and in a manner, embrace the lower articulating processes of the vertebra above them. From each of the superior articulating processes a " tubercle" projects backwards. The transverse processes, 8 long, thin, and horizontal, do not project backwards like those of the dorsal vertebrae. The spinous process. 6. is broad, flat, and nearly of square form so that it terminates not by a pointed extremity, like those in the dorsal region, but presents rather a compressed and rough border. The plates or laminae, though shorter, are deeper and thicker than those of the dorsal vertebrae.
If, now, the three vertebrae (cervical, dorsal, and lumbar,) here described separately, are taken together and contrasted, it will be found that the several parts of one differ so much from the same parts in another, and are so characteristic of the region to which they belong, that any one of them would serve to distinguish the classes of the vertebrae. Thus, that the ring, the body, or any process would be sufficient to determine whether a vertebra is of the cervical, the dorsal, or the lumbar part of the column.
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