114 LIGAMENTS OF THE PELVIS. 



The superior and inferior costo-sternal ligaments are narrow fas- 

 ciculi corresponding with the breadth of the cartilage, and connect- 

 ing its superior and inferior border with the side of the sternum. 



The synovia! membrane is absent in the articulation of the first 

 rib, its cartilage being usually continuous with the sternum ; that of 

 the second rib has an inter-a-rticular ligament, with two synovial 

 membranes. 



The sixth and seventh ribs have several fasciculi of strong h'ga- 

 mentous fibres, passing from the extremity of their cartilages to the 

 anterior surface of the ensiform cartilage, which they are intended 

 to support. They may be named the costo-xyphoid ligaments. 



The sixth, seventh, and eighth, and sometimes the fifth and the 

 ninth costal cartilages, have articulations with each other, and a 

 perfect synovial membrane. They are connected by ligamentous 

 fibres which pass from one cartilage to the other, external and 

 internal ligaments. 



The ninth and tenth are connected at their extremities by liga- 

 mentous fibres, but have no synovial membranes. 



Actions. The movements of the costo-sternal articulations are 

 very trifling; they are limited to a slight sliding motion. The first 

 rib is the least, and the second the most movable. 



8. Articulation of the Vertebral Column with the Pelvis. The last 

 lumbar vertebra is connected with the sacrum by the same liga- 

 ments with which the various vertebra are connected to each other ; 

 viz. the anterior and posterior common ligaments, intervertebral sub- 

 stance, ligamenta subflava, capsular ligaments, and inter and supra- 

 spinous ligaments. 



There are only two proper ligaments connecting the vertebral 

 column with the pelvis; these are, the 



Lumbo-sacral, 

 Lumbo-iliac. 



The lumbo-sacral ligament is a thick triangular fasciculus of liga- 

 mentous fibres, connected above, with the transverse process of the 

 last lumbar vertebra; and below, with the posterior part of the 

 upper border of the sacrum. 



The lumbo-iliac ligament passes from the apex of the transverse 

 process of the last lumbar vertebra to that part of the crest of the 

 ilium which surmounts the sacro-iliac articulation. It is triangu- 

 lar in form. 



9. The Articulations of the Pelvis. The ligaments belonging to 

 the articulations of the pelvis are divisible into four groups: 1. 

 Those connecting the sacrum and ilium; 2, those passing between 

 the sacrum and ischium; 3, between the sacrum and coccyx; and 4, 

 between the two pubic bones. 



1st, Between the sacrum and ilium. 



Sacro-iliac anterior, 

 Sacro-iliac posterior. 



