92 OSTEOLOGY, OR ANATOMY OF OSSEOUS SYSTEM 



groove for the extensor indicis, extensor communis, and exten- 

 sor minimi digiti. Just above the first groove is an impression 

 for the supinator longus. 



THE BONES OF THE HAND 



The skeleton of the hand consists of three segments wrist 

 hones, bones of the palm (metacarpal), and bones of the 

 fingers (phalanges). 



The carpus, or wrist bones, are composed of eight short 

 bones arranged in two rows: the upper row, from the radial to 

 the ulnar side, comprises the scaphoid, lunar (semilunar), 

 pyramidal (cuneiform), and pisiform; in the inferior row arc 

 the trapezium, trapezoid, os magnum, and unciform. 



THE ARTICULATIONS OF THE CARPAL BONES 



The metacarpus, or bones of the palm, support the fingers, 

 and consist of five long, slightly divergent bones, which articu- 

 late with the carpus as follows: 



The first metacarpal articulates at its base with - one bone. 



The second metacarpal articulates at its base with four bones. 



The third metacarpal articulates at its base with three bones. 



The fourth metacarpal articulates at its base with four bones. 



The fifth metacarpal articulates at its base with two bones. 



