THE CERVICAL VERTEBRAE 49 



body of the vertebra, at the line of junction of its posterior and lateral surfaces. 

 Each pedicle is a root of the vertebral arch. The concavities above and below 

 the pedicles are the superior and inferior intervertebral notches (incisura vertebralis 

 superior et inferior); they are four in number, two on each side, the inferior ones 

 being generally the deeper. When the vertebras are articulated the notches of 

 each contiguous pair of bones form the intervertebral foramina (foramina inter- 

 vertebralia), which communicate with the vertebral canal and transmit the spinal 

 nerves and bloodvessels. 



Laminae. The lamina? are two broad plates of bone which complete the 

 neural arch by fusing together in the middle line behind. They enclose a foramen, 

 the spinal or vertebral foramen (foramen vertebrale), which serves for the protection 

 of the spinal cord. When the vertebras are joined they form, with their ligaments, 

 the vertebral canal (canalis vertebralis). The laminae are connected to the body 

 by means of the pedicles. Their upper and lower borders are rough, for the 

 attachment of the ligamenta subflava. 



Processes. Spinous Process (processus spinosus). The spinous process is 

 a rather long, three-sided mass of bone which projects backward from the 

 junction of the two laminae and may terminate in a tubercle, and serves for the 

 attachment of muscles and ligaments. 



Articular Processes. The articular processes (zygapophyses), four in number, 

 two on each side, spring from the junction of the pedicles with the laminae. Each 

 superior process (processus articularis superior) projects upward, its articular 

 surface (Jades articularis superior) being directed more or less backward; each 

 inferior process (processus articularis inferior) projects downward, its articular 

 surface (fades articularis inferior) looking more or less forward. 1 



Transverse Processes (processus transversi). The transverse processes, two in 

 number, project one at each side from the point where the lamina joins the 

 pedicle, between the superior and inferior articular processes. They also serve 

 for the attachment of muscles and ligaments. 



The Cervical Vertebrae (Vertebrae Cervicales) (Fig. 15). 



The cervical vertebrae are smaller than those in any other region of the spine, 

 and may be readily distinguished by the foramen in the transverse process, which 

 does not exist in the transverse process of either a thoracic or lumbar vertebra. 



Body. The body is small, comparatively dense, and broader from side to 

 side than from before backward. The anterior and posterior surfaces are flattened 

 and of equal depth; the former is placed on a lower level than the latter, and its 

 inferior border is prolonged downward, so as to overlap the upper and fore part 

 of the vertebra below. Its upper surface is concave transversely, and presents 

 a projecting lip on each side; its lower surface is convex from side to side, concave 

 from before backward, and presents laterally a shallow concavity which receives 

 the corresponding projecting lip of the adjacent vertebra. 



Pedicles. The pedicles are directed outward and backward, and are attached 

 to the body midway between the upper and lower borders; so that the superior 

 intervertebral notch is as deep as the inferior, but it is, at the same time, narrower. 



Laminae. The laminae are narrow, long, thinner above than below, and 

 overlap each other, enclosing the vertebral foramen, which is very large, and of 

 a triangular form. 



Processes. Spinous Process. The spinous process is short, and bifid at the 

 extremity, to afford greater extent of surface for the attachment of muscles, the 



1 It may, perhaps, be as well to remind the reader that the direction of a surface is determined by that of a 

 line drawn at right angles to it. 



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