Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 16 On the Vertebrae of the Thorax

Diversity in the bodies of thoracic vertebrae.

First, the bodies of the thoracic vertebrae vary in size to the degree one is closer to the neck than the other (the first of the figures showing all the bones and the fig. for ch. 14 show this variation of articulation and bulk). The body of the first thoracic vertebra is thus quite smaller than the twelfth. Next, the body of the first, on its superior surface where it is joined to the seventh cervical vertebra, is not entirely flat but swells slightly at each side and subtly imitates the bodies of the cervical vertebrae (h, k, q in fig. 9, ch. 15); but the lower part of this body has a flat surface like the upper and lower surfaces of the bodies of all thoracic vertebrae (A in figs. 1, 2, 3). No lower portion of the body in the thoracic vertebrae is in fact extended even the least bit in a long downward slope or ends in a depression of the body of the next vertebra, as do the cervical vertebrae (r in fig. 8 and z in fig. 9, ch. 15). Yet Galen attests otherwise 14 , attributing more or less the same articulation to the thoracic vertebrae as we have shown in the preceding chapter that the bodies of the cervical vertebrae construct. Moreover, the bodies of the first and second thoracic vertebrae do not protrude forward with a round or curving anterior shape as much as the bodies of the other thoracic vertebrae, which much more resemble a circle or the letter C than the highest vertebrae, and protrude farther into the thoracic cavity. The two upper vertebrae of the thorax, like the cervical vertebrae, are depressed in their anterior surface and are much broader (so to speak) than deeper, and conform to the bulge of a half parenthesis, “(” , rather than a C. This special feature occurs in them not only to provide a loose articulation fit for motion but also for the muscles that flex the neck (A and B in the 8th table of muscles) [m. longus capitis]. For those muscles are so laid out upon both sides of the bodies of the first thoracic and all the cervical vertebrae that it is clear the vertebrae are compressed by them. But the remaining vertebral bodies have no such muscles attached or lying upon them. 15 It also happens to all the thoracic vertebrae alike that they have a depression on each side [fovea costalis superior corporis vertebrae] to which the capitula of the ribs [facies articularis superior capitis costae] are articulated.



Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 16 On the Vertebrae of the Thorax