chap, xv.) THE WRIST AND HAND. 259 



The posterior interosseous vessels will be cut long, 

 and will be found 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 out about the wri&t: Commencing at 

 the outer side, the lower extremity and styloid process 

 of the radius can be well denned. 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 brevis pollicis. 

 These are very distinct when the thumb is abducted, 

 and the slit-like interval between the 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 i-adial 



