198 



ARTICULATIONS. 



brae ; 2. Those which connect the neck and tubercle of the ribs with the trans- 

 verse processes. 



1. AKTICULATION BETWEEN THE HEADS OF THE BIBS AND THE BODIES 



OF THE 



Anterior View. 



These constitute a series of angular ginglymoid joints, formed by the articula- 

 tion of the heads of the ribs with the cavities on the contiguous margins of the 

 bodies of the dorsal vertebrae, connected together by the following ligaments : 



Anterior Costo-vertebral or Stellate. 



Capsular. 



Interarticular. 



The Anterior Costo-vertebral or Stellate Ligament (fig. 124) connects the anterior 



part of the head of each 



Fig. 124. Costo-vertebral and Costo-transverse Articulations. rib, with the Sides of the 



bodies of the vertebrae, 

 and the intervening in- 

 tervertebraldisk. It con- 

 sists of three flat bundles 

 of ligamentous fibres, 

 which radiate from the 

 anterior part of the head 

 of the rib. The superior 

 fasciculus passes up- 

 wards to be connected 

 with the body of the 

 vertebra above ; the in- 

 ferior one descends to 

 the body of the vertebra 

 below; and the middle 

 one, the smallest and 

 least distinct, passes ho- 

 rizontally inwards to be 

 attached to the interver- 

 tebral substance. 



Relations, In front, 

 with the thoracic ganglia 

 of the sympathetic, the 

 pleura, and, on the right 



side, with the vena azygos major ; behind, with the interarticular ligament and 

 synovial membranes. 



In the first rib, which articulates with a single vertebra only, this ligament does 

 not present a distinct division into three fasciculi ; its superior fibres, however, 

 pass to be attached to the body of the last cervical vertebra, as well as to the 

 body of the vertebra with which the rib articulates. In the eleventh and twelfth 

 ribs, which also articulate with a single vertebra, the same division does not exist ; 

 but the upper fibres of the ligament, in each case, are connected with the vertebra 

 above, as well as to that with which the ribs articulate. 



The Capsular Ligament is a thin and loose ligamentous bag, which surrounds 

 the joint between the head of the rib and the articular cavity formed by the junc- 

 tion of the vertebrae. It is very thin, firmly connected with the anterior ligament, 

 and most distinct at the upper and lower parts of the articulation. 



The Interarticular Ligament is situated in the interior of the joint. It consists 

 of a short band of fibres, flattened from above downwards, attached by one extremity 

 to the sharp crest on the head of the rib, and by the other to the intervertebral 

 disk. It divides the joint into two cavities, which have no communication with 

 one another, and are each lined by a separate synovial membrane. In the firsts 



J.eu*er Synoeuti 



