130 LIGAMENTS OF THE PELVIS. 



The superior and inferior costo-sternal ligaments are narrow fasciculi 

 corresponding with the breadth of the cartilage, and connecting its 

 superior and inferior border with the side of the sternum. 



The synovial membrane is absent in the articulation of the first rib, 

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

 second rib lias an inter-articular ligament, with two synovial mem- 

 branes. 



The sixth and seventh ribs have several fasciculi of strong ligament- 

 ous fibres, passing from the extremity of their cartilages to the anterior 

 surface of the ensiform cartilage, which latter they are intended to 

 support. They are 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 ligament- 

 ous 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 Sternum. The pieces of the sternum are 

 connected by means of a thin plate of interosseous cartilage placed be- 

 tween each, and by an anterior and posterior ligament. The fibres of 

 the anterior sternal ligament are longitudinal in direction, but so 

 blended with the anterior costo-sternal ligaments, and the tendinous 

 fibres of origin of the pectoral muscles as scarcely to be distinguished 

 as a distinct ligament. The posterior sternal ligament is a broad 

 smooth plane of longitudinal fibres, placed upon the posterior surface 

 of the bone, and extending from the manubriun to the ensiform car- 

 tilage. These ligaments contribute very materially to the strength of 

 the sternum and to the elasticity of the front of the chest. 



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

 lumbar vertebra is connected with the sacrum by the same ligaments 

 with which the various vertebrae are connected to each other ; viz. 

 the anterior and posterior common ligaments, intervertebral substance, 

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

 ligaments. 



There are, however, tivo proper ligaments connecting the vertebral 

 column with the pelvis ; these are, the 



Lum bo-sacral, 

 Lumbo- iliac. 



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

 ous 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 



