1 :{2 / " > i . 



-ive attachment to tin- nm>ele> of the tongue ;,,,,! to others. 

 Tin-van- nut cx>n8ideredapartofthekeleton,properly8OcaUed. 



^ -_'71. '/'/" 7V/////-, w Zbr*>. The most 



iii]|)(irtaiit part of the skeleton of the trunk is the 

 '' verteliral colunin, composed ot'the hones called ver- 

 tebra . It supports the head, which may he con- 

 sidered :is a continuation of it ; hut anatomist.- st ill 

 speak of the vertebral column as a part distinct 

 from the head. In this view it is composed of 

 -,/ :]:} vertebne, namely. 7 cervical (/) ; 12 dorsal (//) ; 



15 lumbar (/); 5 sacral (.v); an< ; -. . I 1 



presents several curves when viewed in profile, but 

 is straight when seen from before backwards, or 

 ml from behind forwards. At first all the vertebra- 

 are distinct, but with years certain of them 

 become fused into one or more: the o sacral 

 - vertebrae generally unite so as to form one n 

 and the coccygeal bones are also disposed to 

 fuse into one bone in the adult. 

 Fig. 79. The essential character of a veitehra (///// cer- 

 tain exceptions, however) is to be formed or com- 

 posed of a body and processes, and to have a foramen, or short 



anal, behind the body, in which the spinal marrow ami its 

 membranes are lodged. But the coccygeal vertebra- in man 



are quite rudimentary, and cannot he included in 

 this definition. At the sides of the column are 

 openings for the passage of the nerves; they are 

 called the foramina intervertehrali: 1 . and are 

 generally formed by the union of two vertebra-. 



The body of a vertebra is a disc (</), with 

 parallel surfaces, each united (with certain 

 tions) to the adjoining vertebra by a substance 



called intervertebral ; this is a tibro-eartilage of great strength. 



llexibility. and elasticity, on which the strength and mohilitv 



if the column greatly depends. 



Four articular processes also greatly contribute to its strength, 

 and limit its movements in certain directions. The spinous 

 - h, as well as the transverse p; _ r ive attach- 



ments to numerous muscles, and the latter support the ribs. 

 The mobility of the column varies in different regions, hein^r 

 \tensive in the neck and loins. The eivctor musc.es 

 of the spine, those intended merely to raise the body upright, 

 and to counterbalance the weight of all the viscera situated in 



