The first dorsal vertebra is marked at each side by a complete articular surface for the first rib, and on its inferior border by a slight excavation, which receives half the head of the second : the upper articular processes are oblique, and the spinous more nearly horizontal than those below it.
The tenth dorsal vertebra is usually marked by an articular surface, which receives the entire of the head of the corresponding rib.
The eleventh has but a single articular surface on the side of its body. Its transverse process is much reduced in size, and does not articulate with the tubercle of the rib. The form of its spinous process, of its laminae and body, approaches that of the lumbar vertebrae.
The twelfth dorsal vertebra, in most of its characters, resembles the eleventh, and is to be distinguished by its greater similarity to the lumbar vertebrae, especially by means of the lower articular processes, which are convex and look outwards, like the same processes in the lumbar region.