4 6 4 



PRACTICAL ANATOMY. 



They are for the attachment of muscles and ligaments. Their ligaments are 

 periosteal, and are named interspinous and supraspinous. (Fig. 335.) 



What is the ligaincntmn nucluz ? 



Literally, the ligament of the nape of the neck. This is a septum of con- 

 nective tissue between the muscles of the back of the neck. Its attachments are 

 the external occipital protuberance (Fig. 338) and the spines of the cervical ver- 

 tebrae. It is rudimentary in man impossible of demonstration in practical 

 anatomy, except as a very feeble intermuscular connective tissue ; not being 

 demonstrable even, in my experience, as an intermuscular septum, such as we 

 find between the peronei muscles and those on the front part of the leg. 



Describe the atlas. 



This is the first of the cervical series of vertebrae. It consists of an anterior 



Vertical portion of crucial 



ligament 

 Central odontoid ligament 



Lateral odontoid ligaments 



Transverse portion of 

 crucial ligament 

 Accessory band of atlanto- 

 azoidean capsules 

 Atlanto-azoidean joint 



Oocipito-cervioal or cervico-basilar 

 ligament 



Posterior common ligament 



FIG. 336. VERTICAL TRANSVERSE SECTION OF THE SPINAL COLUMN AND THE OCCIPITAL I><M 



TO SHOW LIGAMENTS. 



(The cervico-basilar (l), though shown as a distinct stratum, is really the deeper part of 

 the posterior common ligament (2).) 



arch, a posterior arch, and two lateral masses. Morphologically, its divorced or 

 dismembered body obtains as the odontoid process of the axis. 



Give composition of the lateral mass. 



The lateral mass consists of (i) a superior articular process that articulates 

 with the occipital condyle ; (2) an inferior articular process that articulates with 

 the axis ; (3) costal process a rudimentary rib ; (4) a transverse process for 

 muscular attachment; (5) a costotransverse foramen for the vertebral artery; 

 (6) tubercles for attachment of the transverse liganu nt. 



\Vhat do YOU find at the junction of the lateral mass and the posterior arch / 



A groove for the lodgement of the vertebral artery. 



\\ liat is peculiar about tlie relation of the articular processes of the axis and 

 atlas to (lie spinal nerves f 



In these vertebrae the nerves issue behind the articular processes ; the remain- 

 ing spinal nerves issue in front of the articular facets or processes. 



