OF THE RIBS WITH THEIR CARTILAGES. 



335 



oblong-shaped facets. Each articulation is enclosed in a thin capsular ligament 

 lined by ftynovial membrane, and strengthened externally and internally by liga- 

 mentous fibres (interchondral ligaments) which pass from one cartilage to the 

 other. Sometimes the fifth costal cartilage, more rarely that of the ninth, articu- 

 lates, by its lower border, with the adjoining cartilage by a small oval facet ; more 



The synovial cavities exposed by 

 a vertical section of the sternum and curtilages. 



Cartilage continous with 

 sternum. 



ana 

 two synovial membranes. 



Single synovial 

 membrane. 



FIG. 238. Chondro-sternal, chondro-xiphoid. and interchondral articulations. Anterior view. 



frequently they are connected together by a few ligamentous fibres. Occasionally 

 the articular surfaces above mentioned are wanting. 



Articulations of the Ribs with their Cartilages (Costo-chondral) 



(Fig. 238). 



The outer extremity of each costal cartilage is received into a depression in the 

 sternal end of the ribs, and the two are held together by the periosteum. 





