CERVICAL VERTEBRA. 



141 



the trunk : for, when we bow forwards, the weight bears 

 entirely on the bodies of the vertebrae ; if we bend back, the 

 obHque processes support it ; if we recline to one side, we rest 

 upon the oblique processes of that side and part of the bodies ; 

 if we stand erect all the bodies and oblique processes have their 

 share in our support. 



The irue veriebne are divided into three classes, which agree 

 with each other in their general structure, but are distinguished 

 by several peculiarities. 



These classes are named Cervical, Dorsal, and Lumbar. 

 The CERVICAL are the seven uppermost vertebrae ; which 

 are distinguished from the rest by these marks : their bodies 

 are smaller and more solid than any others ; and are flattened on 

 the front surface. They are also flat behind, where small 

 processes rise, to which the internal ligaments are fixed. The 

 upper surface of the body of each vertebrae is made hollow, 

 by a slanting thin process which is raised on each side. The 

 lower surface is also hollowed, but in a different manner; for 

 here the posterior edge is raised a little, and the anterior one 

 is considerably extended. Hence, the cartilages between these 

 vertebra? are firmly connected, and their articulations are 

 secure. 



Fig. 33.* These cartilages are thick, especially 



at their forepart ; which is one rea- 

 son why the vertebra? project for- 

 ward as they descend, and have the 

 larger motion. 



Their oblique processes more justly 

 deserve that name than those of any 

 other vertebrae. They are situated 

 slanting ; the upper ones having their 

 smooth and almost flat surfaces facing obliquely backwards 



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

 concave in its middle, and rising on each side into a slanting thin process or 

 ridge. 2. The lamina or lamella. 3. The pedicle rendered concave by the 

 superior intervertebral notch. 4. The bifid spinous process. 5. The bifid or 

 notched transverse process. 6. The vertebral foramen. 7. The superior oblique 

 or articular process. 8. The inferior oblique or articular process. 



