44 HUMAN ANATOMY. 



The laminae arc two broad, flat plates of bone, projecting 

 backward and inward from the pedicles, to complete the verte- 

 bral arch and inclose the spinal foramen. Their upper and 

 lower margins are rough for attachment of the ligamenta sub- 

 flava. 



The spinous processes vary much in size and shape in the 

 different regions. They project backward from the junction 

 of the laminae, and afford attachment for muscles. 



The transverse processes project, one on each side, from 

 the junction of the laminae with the pedicles, and in the cervical 

 region from the sides of the body also, inclosing the foramen 

 for the vertebral artery. 



The articular processes, four in number, project one above 

 and below on each side, from the junction of the laminas and 

 pedicles. The two superior project upward and more or less 

 backward, the inferior downward and more or less forward, 

 articulating with the corresponding processes of the adjoining 

 vertebra. 



The spinal foramen is a large, triangular canal, inclosed 

 by the body in front, the pedicles laterally, and the laminae be- 

 hind for the passage of the spinal cord and its membranes. 



THE CERVICAL VERTEBRAE are characterized by small body, 

 concave above, convex below, the anterior margin overlapping the 

 one below; short and bifid transverse process, perforated at 

 base by foramen for vertebral artery ; oblique articular processes 

 superior convex directed upward and backward, inferior con- 

 cave downward and forward ; short spinous process, bifid, placed 

 horizontally ; long and narrow lamina, inclosing large, triangular 

 spinal canal. 



The peculiar cervical vertebrae are first, second, and seventh. 



The first or atlas is ring-like, without either body or spinous 

 process, and consists of an anterior and posterior arch and two 

 lateral masses. The anterior arch, convex in front, presents 

 tubercle for longus colli muscles and behind articulates with 

 odontoid process of axis. The posterior arch is deeply grooved 

 above for transmission of vertebral artery and suboccipital nerves, 

 and terminates behind in a rudimentary spine. It articulates 

 above with condyles of occipital, below with axis. The trans- 

 verse process is short and contains a foramen. 



The axis, so-called from the pivot-like odontoid process, 

 which projects from the upper part of its body to articulate with 

 the anterior arch and transverse ligament of atlas. 



The seventh resembles the dorsal series, its spinous process 

 being long, not bifid, and prominent; hence its name, "vertebra 

 prominens." To it is attached the ligamentum nuchae. 



