THE SKELETON 



343 



there are 3 little bones in each ear. This makes a total 

 of 28 bones in the head. 



The backbone, or spinal column, consists of 24 bony 

 rings, or vertebrae (cf. 341). There are, in addition, 

 two bones at the base of 

 the backbone; these are 

 called the sacrum and the 

 coccyx. 



Twelve of the vertebrae 

 have 2 ribs each. The 7 

 upper pairs of ribs are 

 joined in front to the 

 sternum, or breast bone, 

 and are called true ribs. 

 The 5 lower pairs of ribs 

 are called false ribs. The 

 3 upper pairs of false ribs 

 are joined to the lowest 

 pair of true ribs. The 2 

 lowest pairs of false ribs 

 are not attached, in front, 

 to anything, and are called 

 floating ribs. The shoulder 

 bones are 2 clavicles (collar 

 bones) and 2 scapulas 

 (shoulder blades). There 

 is also a hyoid bone at the 

 base of the tongue. The 

 lower end of the abdomen 

 is supported by the sacrum and coccyx bones of the 

 spinal column, and by the 2 pelvic, or hip, bones. 



FIG. 276. 

 Surface Muscles of the Body, 



