THE RIBS. 



101 



and two floating. The upper five are the true ribs; 

 they arch outward from the vertebral column, and are 

 continued to the sternum, each by a single piece of costal 

 cartilage (the true costal cartilages). The false ribs are 

 the sixth, seventh, eighth, ninth, and tenth, and are 



FIG. 46. THE PECULIAK RIBS. 



articulated anteriorly with the sternum through the 

 medium of the false costal cartilages. The eleventh and 

 twelfth are the floating ribs. A rib presents for exami- 

 nation a head, a neck, a tuberosity, shaft, angle and 

 sternal extremity. The head, flattened, reniform in out- 

 line, presents two articular facets, an upper smaller and 



