CERVICAL VERTEBRA. 11 



attachment of muscles. The articular processes, four in number, 

 stand upwards and downwards from the laminae of the vertebra to 

 articulate with the vertebra above and below. 



Cervical Vertebrae. In # 



a cervical vertebra the body 

 is smaller than in the other 

 regions ; it is thicker be- 

 fore than behind, broad from 

 side to side, concave on the 

 upper surface, and convex 

 below ; so that when arti- 

 culated, the vertebrae lock 

 the one into the other. The 

 laminae are narrow and long, 

 and the included spinal 

 foramen large and triangu- 

 lar. The superior interver- 

 tebral notches are slightly 



deeper than the inferior ; the inferior being the broadest. The 

 spinous process is short and bifid at the extremity, increasing in length 

 from the fourth to the seventh. The transverse processes are also short 

 and bifid, and deeply grooved along the upper surface for the cervical 

 nerves. Piercing the base of the transverse process is the vertebral 

 foramen f which gives passage to the vertebral artery and vein, and 

 vertebral plexus of nerves. The transverse processes in this region, 

 are formed by two small developments which proceed, the one from the 

 side of the body, the other from the pedicle of the vertebra, and unite 

 near their extremities to enclose the circular area of the vertebral fora- 

 men. The anterior of these developments is the rudiment of a cervi- 

 cal rib ; and the posterior, the analogue of the transverse processes in 

 the dorsal region. The extremities of these developments are the 

 anterior and posterior tubercles of the transverse process. The articular 

 processes are oblique ; the superior looking upwards and backwards ; 

 and the inferior, downwards and forwards. 



There are three peculiar vertebrae in the cervical region : The first 

 or atlas ; the second or axis ; and the seventh or vertebra promi- 

 nens. 



The Atlas (named from supporting the head) is a simple ring of 

 bone, without body and composed of arches and processes. The an- 



* A central cervical vertebra, seen upon its upper surface. 1. The body, 

 concave in the middle, and rising on each side into a sharp ridge. 2. The 

 lamina. 3. The pedicle rendered concave by the superior intervertebral notch. 

 4. The bifid spinous process. 5. The bifid transverse process. The figure is 

 placed in the concavity between the anterior and posterior tubercles, between 

 the two processes which correspond with the rudimentary rib and the true 

 transverse process. 6. The vertebral foramen. 7. The superior articular pro- 

 cess, looking backwards and upwards. 8. The inferior articular process. 



t Sometimes, as in a vertebra now before me, a small additional opening 

 exists by the side of the vertebral foramen, in which case it is traversed by a 

 second vein. 



