Vertebral Column 23 



in the recent state by the posterior common ligament : deep to the ligament, veins 

 issue from the back of the body (Venae basis vertebrae) by foramina which tend to be 

 paired but may be multiple. 



It remains to consider the upper two vertebrae. 



The Axis, on its front surface, shows a narrow ligamentous area which indicates 

 the cord-like nature of the upper part of the anterior common ligament : outside this 

 the muscular hollow is overhung above and externally by the front edge of the upper 

 articular process, roughened by the capsular ligament. On the base of the transverse 

 process, where it projects from under the articular edge, is an ill-defined tubercle, to 

 which some oblique fibres of the capsule are attached. 



This tubercle, seen in Figs. 16 and 19, is the proper " anterior tubercle " of 

 the transverse process, and the quasi- process projecting from it is really the costo- 

 transverse bar connecting this tubercle with the true transverse element behind ; so 

 the tip is only the "posterior tubercle.'" The correspondence of the parts of the 

 " transverse processes " in this vertebra and the next are shown in Fig. 15, B, and it is 

 evident that the intertransverse muscle on the top of the second process is only the 

 representative of the posterior intertransverse on the third, while the anterior inter- 

 transverse is wanting * in the former case ; thus the anterior primary division of 

 the second nerve, descriptively issuing " internal to the intertransverse muscles," is 

 really in the same plane as the lower nerves that come out between them, and lies, 

 as they do, on the costo-transverse bar. The nerves are shown, with their relations to 

 the artery, in this figure and in Fig. 17. 



The oblique ligamentous fibres correspond with the upper bands of the stellate 

 ligaments of the rib-heads in the thorax, and lie in front of the articulation, which we 

 have seen to be of the nature of a costo-central joint. 



The tip of the transverse process has a sharp posterior lip : the aponeurosis of 

 the Splenius colli is attached to this. In front of this and rather above it, on the 

 tubercle, is a rounded small surface for Lev. anguli scapulae, and internal to this a 

 slight ridge marks the origin of the top fibres of Scalenus medius. The intertransverse 

 muscle is attached to the top of the tubercle and true transverse limb, extending 

 slightly on to the costo-transverse bar. 



The groove on the neural arch behind and outside the upper articular area is for 

 the anterior primary division of the second cervical nerve : the posterior division, or 

 great occipital, crosses the arch a little further back, lying on it under cover of the 

 inferior oblique (see Fig. 18). Two areas can be seen and felt on the surface of the spine 

 and lamina : one concave, and looking upwards and outwards on the spine and 

 extending forward about half-way to the articular surface, the other a rough and 

 narrower area looking downwards and outwards and extending from the lower margin 

 of the spine toward the lower articular eminence. The upper one gives origin to the 

 Inferior Oblique, and the lower affords insertion to Semispinalis colli and Multifidus 

 spinee, the last named also reaching the lower aspect of the lamina : this makes the 

 lamina thick below, giving it a three-sided section, with a sharp upper border for 

 attachment of lig. subflavum. The crest on the upper and back aspect of the spine 

 gives origin to the Rectus posticus major. 



The neural aspect of the laminae shows a transverse line above its lower border 

 for deep fibres of the lig. subflavum. 



The back of the body joins the back of the odontoid process at the level of a ridge 



* There are muscle fibres of this group to be found sometimes attached to the " anterior tubercle," 

 internal to the issuing nerve. Usually these form an oblique ligamentous band. 



