ULNAR ARTERY. 329 



The Carpal branches are intended for the supply of the wrist, the 

 anterior carpal in front, and the posterior, the larger of the two, be- 

 hind. The carpalis posterior crosses the carpus transversely to the 

 ulnar border of the hand, where it inosculates with the posterior car- 

 pal branch of the lilnar artery. Superiorly it sends branches which 

 inosculate with the termination of the anterior interosseous artery ; 

 inferiorly, it gives off posterior interosseous branches, which anastomose 

 with the perforating branches of the deep palmar arch, and then run 

 forward upon the dorsal interossei muscles. 



The Metacarpal branch runs forward on the second dorsal interos- 

 seous muscle, and inosculates with the digital branch of the superficial 

 palmar arch, which supplies the adjoining sides of the index and mid- 

 dle fingers. Sometimes it is of large size, and the true continuation 

 of the radial artery. 



The Dorsales pollicis are two small branches which run along the 

 sides of the dorsal aspect of the thumb. 



The Princeps pollicis descends along the border of the metacarpal 

 bone, between the abductor indicis and adductor pollicis to the base of 

 the first phalanx, where it divides into two branches, which are dis- 

 tributed to the two sides of the palmar aspect of the thumb. 



The Radialis indicis is also situated between the abductor indicis 

 the adductor pollicis, and runs along the radial side of the index finger, 

 forming its collateral artery. This vessel is frequently a branch of 

 the princeps pollicis. 



The Interossece, three or four in number, are branches of the deep 

 palmar arch ; they pass forward upon the interossei muscles and in- 

 osculate with the digital branches of the superficial arch, opposite the 

 heads of the metacarpal bones. 



The Perforantes, three in number, pass directly backwards between 

 the heads of the dorsal interossei muscles, and inosculate with the 

 posterior interosseous arteries. 



ULNAR ARTERY. 



The Ulnar artery, the other division of the brachial artery, crosses 

 the arm obliquely to the commencement of its middle third ; it then 

 runs down the ulnar side of the fore- arm to the wrist, crosses the an- 

 nular ligament, and forms the superficial palmar arch, which terminates 

 by inosculating with the superficialis volse. 



Relations. In the upper or oblique portion of its course, it lies 

 upon the brachialis anticus and flexor profundus digitorum ; and is 

 covered in by the superficial layer of muscles of the fore-arm and the 

 median nerve. In the second part of its course, it is placed upon the 

 flexor profundus and pronator quadratus, lying between the flexor 

 carpi ulnaris and flexor sublimis digitorum. While crossing the annu- 

 lar ligament it is protected from injury by a strong tendinous arch, 

 thrown over it from the pisiform bone ; and in the palm it rests upon 

 the tendons of the flexor subb'mis, being covered in by the palmaris 



