40 ANATOMY AND PHYSIOLOGY 



POINTS OF SPECIAL INTEREST 



The cervical vertebrae present a foramen at the base of the 

 transverse process, the transverse foramen, through which an artery 

 runs to the brain, entering the skull through the foramen mag- 

 num. (There are no transverse foramina in the dorsal or lumbar 

 regions.) 



Their spinous processes are cleft or bifid. 



Transverse foramen 

 Transverse process 



Articular process 



Lamina 



Spinous process 



Pedicle 



FIG. 32. CERVICAL VERTEBRA, SHOWING BIFID SPINOUS PROCESS. (Morris.) 



FIG. 33. ATLAS, SUPERIOR SURFACE. 

 i, Tubercle of anterior arch; 2, 

 articular facet for odontoid process 

 of axis; 3, posterior arch and posterior 

 tubercle; 4, groove for vertebral artery 

 and first cervical nerve; 5, transverse 

 process; 6, transverse foramen; 7, 

 superior articular process; 8, tubercle 

 for attachment of transverse ligament. 

 (Sappey.) 



FIG. 34. Axis POSTERO- 

 SUPERIOR VIEW. 

 i, Posterior surface ot 

 body; 2, odontoid proc- 

 ' e ss; 3, 3, superior articu- 

 lar processes; 4, 4, inferior 

 articular processes; 5, 



5, transverse processes; 



6, spinous process. 

 (Sappey.) 



The first is called the atlas It is a mere ring but has the usual number of 

 processes (Fig. 33). The atlas is so named because it bears the weight of the 

 skull (as Atlas, the fabled giant, bore the globe upon his shoulders). 



The second is the axis. A strong process projects upward from its body 

 forming a pivot for the ring-like atlas to revolve around. The pivot is caUed 



