160 ANATOMY OF UPPER EXTREMITY, ETC. 



The oblique ligament is a slender band, sometimes wam 

 ing, which extends from the front of the coronoicl process 

 to the radius below its tubercle. 



The tendon of insertion of the biceps muscle may now be 

 examined better than could be done previously ; a bursa is 

 found between it and the bone ; near its attachment the 

 tendon twists, its anterior surface becoming external, and 

 vice versa. 



The interosseous membrane is a thin fibrous la}^er, at- 

 tached to the contiguous margins of the radius and ulna, 

 separating the muscles of the front and back part of 

 the forearm ; its fibres are directed obliquely downward 

 toward the ulna ; superiorly the membrane is wanting. 



The WRIST-JOINT is maintained by four ligaments : 



The external lateral ligament is a short strong band be- 

 tween the stj^loid process of the radius and the upper part 

 of the scaphoid bone. 



The internal lateral ligament is smaller but longer than 

 the external ; it extends between the styloid process of the 

 ulna and the upper part of the cuneiform bone. 



The anterior ligament is a membranous layer reaching 

 from the end of the radius to the anterior surface of the 

 first row of carpal bones. 



The posterior ligament is also a membranous layer, and 

 extends from the lower end of the radius to the posterior 

 aspect of the first row of carpal bones. 



The radius and ulna are held together at their lower arti- 

 culation by a triangular fibro-cartilage, placed between 

 them ; this is attached b}' its apex to the inner surface of 

 the styloid process of the ulna, and by its base to the edge 

 of the lesser articulating surface of the radius ; a few scat- 

 tered fibres loosely surround this joint by way of a capsular 

 ligament. 



The carpal bones are united into two rows by dorsal, pal- 

 mar, and interosseous bands, and the two rows are simi- 

 larly united with each other; they are all supplied by one 

 sy no vial membrane, except the pisiform bone, which has a 

 capsule and synovial membrane distinct from the others ; 

 it has also two special ligaments, one to the process of the 

 imciform bone and the other to the base of the fifth meta- 

 carpal bone. 



