20 A MANUAL OF ANATOMY 



is directed straight backwards, and terminates in a single large 

 tubercular eminence. The other characters of this vertebra to 

 be noted are as follows : the antero-posterior measurement of 

 the body exceeds that of other cervical vertebrae ; the trans- 

 verse process is massive and comparatively long ; the posterior 

 tubercle is very distinct, but the anterior is rudimentary, or 

 wanting ; the costo- transverse foramen is of small size, and does 

 not transmit the vertebral vessels and vertebral sympathetic 

 plexus. The vertebral vein, however, may pass through it. 



Varieties. — (i) The costal process may remain separate from the transverse 

 process, thus giving rise to a cervical rib. (2) The costal process may be 

 wanting on one or both sides, in which cases there is no costo-transverse 

 foramen. 



Fig. 12 — The Seventh Cervical Vertebra (Superior View). 



(The Costal Process of the Left Side was undeveloped in this vertebra.) 



It is to be noted that the sixth cervical vertebra is peculiar in the 

 following respects : the spinous process, like that of the vertebra 

 prommens, terminates in a single large tubercular eminence; 

 and the tubercle of each costal process, known as the anterior 

 tubercle, is of large size, and is called the carotid tubercle of jChas- 

 saignac. 



The cervical vertebrae receive their blood-supply from branches 

 of the vertebral arteries. 



The Thoracic Vertebrae. 



The thoracic vertebrae are twelve in number, and their distinctive 

 character is the presence of one or more facets on either side of 

 the bodies for articulation with the heads of ribs. The first. 



