THORACIC JOINTS 115 



costo-transverse bands, the anterior and posterior costo-trans- 

 verse ligaments and the ligament of the neck of the rib. 

 The anterior costo-transverse ligament ascends from the 

 anterior margin of the upper border of the neck of the rib 

 to the lower border of the transverse process above. The 

 posterior costo-transverse ligament passes upwards from the 

 posterior part of the upper border of the neck of the rib to 

 the junction of the lamina and the transverse process of 

 the vertebra above ; and the ligament of the neck of the rib 

 (O.T. middle costo-transverse ligament] connects the posterior 

 aspect of the neck of the rib with the anterior aspect of the 

 transverse process of the vertebra of the same number. 



In the case of the eleventh rib the costo-transverse liga- 

 ments are rudimentary or absent, and in the case of the 

 twelfth rib they are usually entirely absent. 



Intervertebral Articulations. The bodies of the vertebrae 

 are held together by a series of synchondrodial joints, sup- 

 ported anteriorly by an anterior longitudinal ligament, and 

 posteriorly by a posterior longitudinal ligament. The vertebral 

 arches, by means of the articular processes, form a series of 

 diarthrodial joints surrounded by capsular ligaments, each 

 capsule being lined with a synovial stratum. Certain ligaments 

 pass between different portions of the vertebral arches and their 

 processes, viz., the ligamenta flava between adjacent laminae, 

 the inter-transverse, the inter-spinous, and the supra-spinous 

 ligaments. 



The laminae and the spinous processes of the vertebrae have been 

 removed by the dissector of the head and neck in opening up the vertebral 

 canal to display the spinal medulla. Consequently, the ligamenta flava, 

 the inter-spinous and supra-spinous ligaments, cannot be seen at present. 



The anterior longitudinal ligament (O.T. anterior common 

 ligament} is situated- anterior to the bodies of the vertebrae, 

 and extends from the atlas vertebra above to the first piece 

 of the sacrum below. It consists of stout glistening fibrous 

 bands, which are firmly attached to the margins of the verte- 

 bral bodies and to the intervertebral fibro-cartilages. The 

 most superficial fibres are the longest, and extend from a 

 given vertebra to the fourth or fifth below it. The deeper 

 fibres have a shorter course, and pass between the borders 

 of two, three, or four adjacent vertebrae. The dissector 

 cannot fail to notice that the origin of the longus colli muscle 

 is inseparably connected with this ligament, 

 ii 8 a 



