FOREARM AND HAND 143 



by the deep head of the pronator teres. The ulnar nerve in 

 the proximal third of the forearm is separated from the 

 vessel by a wide interval, but in the distal two-thirds of the 

 forearm it closely accompanies the artery, and lies on its 

 medial side. 



In the cubital fossa the ulnar artery rests upon the 

 brachialis ; more distally it is in contact posteriorly with the 

 flexor digitorum profundus ; whilst at the wrist the artery lies 

 upon the superficial surface of the transverse carpal ligament. 



Branches of the Ulnar Artery. In the forearm the ulnar 

 artery gives off the following branches : 



1. A. recurrens ulnaris volaris. 



2. A. recurrens ulnaris dorsalis. 



3. A. interossea communis. 



4. A. carpea volaris. 



5. A. carpea dorsalis. 



6. Rami musculares. 



The muscular branches are of small size, and come off at 

 variable points for the supply of the neighbouring muscles. 



The volar ulnar recurrent artery (O.T. anterior ulnar re- 

 current) is the smaller of the two recurrent branches. It runs 

 proximally, anterior to the medial epicondyle of the humerus, 

 in the interval between the pronator teres and the brachialis 

 muscles, and it anastomoses with the anterior terminal branch 

 of the inferior ulnar collateral artery. 



The dorsal ulnar recurrent artery (O.T. posterior ulnar 

 recurrent] passes medially, under cover of the flexor digitorum 

 sublimis, and then turns proximally, between the two heads 

 of origin of the flexor carpi ulnaris, to gain the interval 

 between the medial epicondyle of the humerus and the 

 olecranon, on the dorsal aspect of the limb. There it becomes 

 associated with the ulnar nerve, and anastomoses with the 

 posterior terminal branch of the inferior ulnar collateral artery 

 and with the superior ulnar collateral artery. 



It is not uncommon to find the two recurrent arteries 

 arising from the ulnar trunk by a short common stem. 



The common interosseous artery is a short, wide trunk, which 

 takes origin immediately distal to the recurrent branches, 

 about 25 mm. (one inch) from the commencement of the ulnar 

 artery. It passes dorsally to the proximal margin of the 

 interosseous membrane, where it divides into two terminal 

 branches, viz., the volar (O.T. anterior] and the dorsal (O.T. 

 posterior] interosseous arteries. 



The arteria interossea dorsalis passes backwards above 



