chap, xv.i THE WRIST AND HAND. 235 



The posterior interosseous vessels will be cut long, 

 and will be fqimd between the superficial and deep 

 muscles. 



Fig. 25 shows the relation of the parts as they 

 would be cut in a circular amputation of the limb 

 through the lower third. 



CHAPTER XV. 



THE WRIST AND HAND. 



Surface anatomy* The following structures 

 can be made put about the wrist: Commencing at 

 the outer side, the lower extremity and styloid process 

 of the radius can be well defined. The bone is here 

 superficial in front and behind. The styloid process 

 lies more anteriorly than does the corresponding 

 process of the ulna, and also descends about half an 

 inch lower down the limb. The outer surface of the 

 radius at the wrist is crossed by the tendons of the 

 extensor ossis metacarpi and extensor primi inter- 

 nodii pollicis. These are very distinct when the 

 thumb is abducted, and the slit-like interval between 

 ohe two can be felt. About the centre of the front of 

 the wrist is the palmaris longus tendon, which is usually 

 the most conspicuous of the tendons on this aspect 

 of the joint. It is rendered most prominent when the 

 wrist is a little flexed, the fingers and thumbs ex- 

 tended, and the thenar and hypothenar eminences as 

 much approximated as possible. A little to its outer 

 side is the larger but less prominent tendon of the 

 flexor carpi radialis. In the narrow groove between 

 these two tendons lies the median nerve, and on the 

 radial side of the flexor carpi radialis is the radial 



