OF THE RIBS WITH THE STERNUM. 



279 



Fig. 193. Costo-sternal, Costo-xiphoid, and Intercostal Articulations. Anterior View. 



ITif tynovidl cavities exposed 

 by a, vertical section jftAe Sternum It Ca.rtilj.ge4 



Actions. The movements which are permitted in the costo-sternal articula- 

 tions, are limited to elevation and depression ; and these only to a slight extent. 



ARTICULATION OF THE CABTILAGES OP THE EIBS WITH EACH OTHER. (Fig. 193.) 



The cartilages of the sixth, seventh, and eighth ribs articulate, by their lower 

 borders with the corresponding margin of the adjoining cartilages, by means of 

 a small, smooth, oblong-shaped facet. Each articulation is inclosed in a thin 

 capsular ligament, lined by synovial 7nembrane, and strengthened externally and 

 internally by ligamentous fibres (intercostal ligaments), which pass from one 

 cartilage to the other. Sometimes the cartilage of the fifth rib, more rarely 

 that of the ninth, articulates, by its lower border, with the adjoining cartilage 

 by a small oval facet; more frequently they are connected together by a few 

 ligamentous fibres. Occasionally, the articular surfaces above mentioned are 

 wanting. 



