82 



Bones of the Upper Extremity. 



103. The Left Shoulder-Blade, Scapula, from before. 



The scapula has : an anterior, a posterior surface, an internal, 

 external and superior border, an inferior, superior external and 

 superior internal angle, finally two processes. The bone covers the 

 posterior surface of the 2. to the 7. 8. ribs. 



The anterior surface is somewhat concave, and is marked by 

 35 ridges, Costae scapular es (for insertions of muscles). The shortest superior 

 border has at its outer end the deep supra-scapular notch, Indsura scapulae. 

 At the superior external, thickened angle is the glenoid cavity, Cavi- 

 tas glenoidalis, for the head of the humerus; the slightly depressed surface which 

 surrounds the head, is called the neck, Collum. 



