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

Structure of the cervical vertebrae.

Although the bodies of the thoracic and lumbar vertebrae are joined to each other with flat and barely convex surfaces in the same way two smooth, broad beams lie against each other (compare the cervical vertebrae here to the thoracic and lumbar vertebrae in the fig. in ch. 14), Nature wished the oblong lower part of the body of the neck vertebrae (z in fig. 9 and r in fig. 8) 114 and of the head to swell in the manner of a joint made for evident motion, and she hollowed out the upper part of the vertebral bodies [corpus vertebrale, facies intervertebralis] (h, q, k in fig. 9 and nos. 1 and 2 in fig. 8) with a broad depression in such a way that the oblong body of the upper vertebra would enter into this depression of the vertebra beneath, and the structure of the vertebrae would rise up more fit for motion. 115 This type of structure 116 is more conspicuous in the connection of the second vertebra with the third, and in some of the vertebrae beneath. The seventh cervical vertebra rests upon the almost totally smooth surface of the first thoracic, and even its own body is not as hollowed on its upper surface as that of the vertebrae above it; this happens chiefly because it was useful for the upper vertebrae to be moved more loosely than the lower. 117 The muscles and ligaments of the vertebrae will show amply in the second book how safely the vertebrae are bound together by ligaments, and how zealously Nature provided for these loose connections of the bones. For the present, let us marvel supremely at the workmanship of God because He provided with such incredible craft at one time for their safety and their complex motion; and no matter how much more frequent the injuries and dislocations of the neck 118 we may see than in the remaining parts of the backbone, yet it should be still more striking


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that so many people are never affected by a fault in a neck having this loose an articulation. We should likewise consider how much inconvenience a rigid and immobile neck would bring to all the tasks of life. The body of the second vertebra is not smooth on its anterior surface (l, m, n in fig. 10) as are the other vertebral bodies of the neck; instead, its form swells with a projection running along its length in the shape of a rather broad line, and is depressed near each side of this projection. This must be attributed to those muscles (A and B in the 8th table of muscles) [m. longus colli] which flex the neck and come together at this point, being inserted more securely into a vertebral body of this shape. But since the third cervical vertebra lies below the second, and a muscle [m. longus colli, pars verticalis] on each side that flexes the neck is inserted on top of this vertebra also, it is no wonder that the anterior face of the body of the third vertebra is quite similar to that of the second: no wonder, indeed, that because of these muscles the surface 119 of all the cervical vertebrae looks compressed and not protuberant in a semicircle 120 like the thoracic or lumbar vertebrae.



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