OF THE ATLAS WITH THE OCCIPITAL BONE. 



325 



ARTICULATIONS OF THE SPINE WITH THE CRANIUM. 



The ligaments connecting the spine with the cranium may be divided into two 

 sets those connecting the occipital bone with the atlas, and those connecting the 

 occipital bone with the axis. 



III. Articulation of the Atlas with the Occipital Bone. 



This articulation is a double condyloid joint. Its ligaments are the 



Two Anterior Occipito-atlantal. Two Lateral Occipito-atlantal. 



Posterior Occipito-atlantal. Two Capsular. 



Of the Two. Anterior Occipito-atlantal Ligaments (Fig. 228), the superficial is 

 a strong, narrow, rounded cord, attached, above, to the basilar process of the 



Arch for passage of 

 vertebral artery 

 and 1st cervical 



FIG. 229. Occipito-atloid and atlo-axoid ligaments. Posterior view. 



occiput ; below, to the tubercle on the anterior arch of the atlas : the deeper liga- 

 ment is a broad and thin membranous layer which passes between the anterior 

 margin of the foramen magnum above, and the whole length of the upper border 

 of the anterior arch of the atlas below. This ligament is in relation, in front, with 

 the Recti antici minores ; behind, with the odontoid ligaments. 



The Posterior Occipito-atlantal Ligament (Fig. 229) is a very broad but thin 

 membranous lamina intimately blended with the dura mater. It is connected, 

 above, to the posterior margin of the foramen magnum ; below, to the upper border 

 of the posterior arch of the atlas. This ligament is incomplete at each side, and 

 forms, with the superior intervertebral notch, an opening for the passage of the 

 vertebral artery and suboccipital nerve. It is in relation, behind, with the Recti 

 postici minores and Obliqui superiores ; in front, with the dura mater of the spinal 

 canal, to which it is intimately adherent. 



The Lateral Ligaments are strong fibrous bands, directed obliquely upward 

 and inward, attached above to the jugular process of the occipital bone ; below, to 

 the base of the transverse process of the atlas. 



The Capsular Ligaments surround the condyles of the occipital bone, and con- 



