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 15 On the Vertebrae of the Neck or Cervix

The remaining description of the first vertebra. 54

Near to the outer sides of the depressions [massa lateralis atlantis, facies articularis superior] that receive the capitula of the occipital bone, the first cervical vetrebra puts forth a single transverse process on each side (S in figs. 2, 3, 4, 10, 11), much longer than the other transverse processes of the neck vertebrae, extended and a bit wider, but not as wide in humans as in dogs and simians with tails, where it is like a kind of wing. The transverse processes of the first vertebra are extended more prominently so that each may receive a more convenient insertion of two muscles [m. obliquus capitis superior] than the transverse processes of the other vertebrae of the neck. Into these processes are separately inserted the fifth (I and H in the 14th table of muscles) [m. obliquus capitis superior] and sixth (L and K in the same table) [m. obliquus capitis inferior] pairs of muscles that move the head. 55 These processes are perforated by a large foramen (T in figure 2) [foramen transversarium] through which a vein and an artery (s in the last fig. of Bk. 3) [arteria et vena vertebralis] going to the skull are borne. Near the posterior part of the depressions in which the head is articulated, a depression (V in figures 3 and 11) [sulcus arteriae vertebralis] is carved in the first vertebra on either side, corresponding to the one (H in fig. 1) [fossa condylaris] that I said was hollowed in the occipital bone near the posterior part of the capitula [condylus]. Both depressions, in the occipital bone and in the first vertebra, together provide a path to the first pair of nerves [nn. cervicales I] of the dorsal medulla. In dogs, not a depression but a special foramen is cut in the first cervical vertebra for this emerging nerve, because their first vertebra is quite wide and deep. This depression [sulcus a. vertebralis] in the human vertebra extends even to the posterior part of the foramen [f. transversarium] by which the transverse process is pierced; thus, this depression makes room not only for a nerve but also for a vein and an artery. It was explained a little earlier that these vessels enter the skull through the foramen (f in ch. 12, fig. 2) [canalis condylaris] carved out near the base of the capitula of the occipital bone. The first vertebra of the neck is the only one that lacks a posterior process or spine, because like a thorn


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it would damage some pairs of muscles and would provide no path or place suitable for them, especially for the third pair of muscles (A and B in the 14th table of muscles) that move the head. Instead, in that part (X in figs. 3, 4, 10 56 , 11) [tuberculum posterius] where the other vertbrae end in a spine, this one is rough and bulges out as if in a sharp line, so that the fourth [third] pair of muscles that move the head (G and F in the 14th table of muscles) 57 may the more easily take their origin from here.



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 15 On the Vertebrae of the Neck or Cervix