THE STERNUM 



119 



The Sternum (Breast Bone). 



The sternum (Figs. 115 to 117) is an elongated, flattened bone, forming the 

 middle portion of the anterior wall of the thorax. Its upper end supports the 

 clavicles, and its margins articulate with the cartilages of the first seven pairs 



STERNOCLEIDOMASTOIDEUS 

 STTBCLAVIUS \ 



Jt/l 



FIG. 115. Anterior surface of sternum and costa cartilages. 



of ribs. It consists of three parts, named from above downward, the manubrium, 

 the body or gladiolus, and the xiphoid process ; in early life the body consists of four 

 segments or sternebrce. In its natural position the inclination of the bone is oblique 

 from above, downward and forward. It is slightly convex in front and concave 





