142 CERVICAL VERTEBRA. 



and upwards ; while the inferior oblique processes have these 

 surfaces facing obliquely forwards and downwards. 



The transverse processes of these vertebrae are formed in a 

 different manner from those of any other bones of the spine ; 

 for, besides the common transverse process rising from between 

 the oblique processes of each side, there is a second one that 

 comes out from the side of the body of each vertebras ; and 

 these two processes, after leaving a circular hole for the passage 

 of the vertebral artery and vein, unite and form a groove on 

 their upper surface to protect the nerves that pass in it. They 

 terminate obtusely on each side, for the insertion of the 

 muscles. 



The spinous processes project backwards almost horizontally. 

 They are shorter than those of any other vertebrae, and are 

 forked or double at their ends ; they therefore allow a more con- 

 venient insertion to muscles. 



The thick cartilages between the bodies of these cervical 

 vertebrae, the obliquity of their oblique processes, and the 

 shortness and horizontal situation of their spinous processes, all 

 conspire to allow them large motion. 



The holes between the bony cross bridges, for the passage 

 of the nerves from the spinal marrow, have their largest share 

 formed in the lowest of the two vertebrae, to which they are 

 common. 



So far most of the cervical vertebrae agree ; but they have 

 some particular differences, which require a separate conside- 

 ration. 



The first, from its use in supporting the head, has the name 

 of atlas. Contrary to all the other vertebra) of the spine, it 

 has no body ; but, instead of it, there is a bony arch. In the 

 convex forepart of this arch a small rising appears ; and on 

 each side of this protuberance, a small cavity may be observed. 

 The upper and lower parts of the arch are rough and unequal, 

 where the ligaments that connect this vertebrae to the os occi- 

 pitis, and to the second vertebra, are fixed. The back part of 

 the arch is concave, smooth, and covered with a cartilage, in 

 a recent subject, to receive the tooth-like process of the second 



