BRANCHES OF RADIAL. 489 



Surgical Anatomy. The operation of tying the radial artery is required in cases of wounds 

 either of its trunk, or of some of its branches, or for aneurism ; and it will be observed, that the 

 vessel may be easily exposed in any part of its course through the forearm. The operation in 

 the middle or inferior third of the forearm is easily performed ; but in the upper third, near the 

 elbow, it is attended with some difficulty, from the greater depth of the vessel, and from its 

 being overlapped by the Supinator Longus aud Pronator Teres muscles. 



To tie the artery in the upper third, an incision three inches in length should be made through 

 the integnment, from the bend of the elbow obliquely downwards and outwards, on the radial 

 side of the forearm, avoiding the branches of the median vein ; the fascia of the arm being 

 divided, and the Supinator Longus drawn a little outwards, the artery will be exposed. The 

 venae comites should be carefully separated from the vessel, and the ligature passed from the 

 radial to the ulnar side. 



In the middle third of the forearm the artery may be exposed by making an incision of similar 

 length on the inner margin of the Supinator Longus. In this situation, the radial nerve lies iu 

 close relation with the outer side of the artery, and should, as well as the veins, be carefully 

 avoided. 



In the lower third, the artery is easily secured by dividing the integument and fasciae in the 

 interval between the tendons of the Supinator Longus and Flexor Carpi Radialis muscles. 



The branches of the radial artery may be divided into three groups, corres- 

 ponding with the three regions in which the vessel is situated: 



f Radial recurrent. f Posterior carpal. 



In the j Muscular. J Metacarpal. 



Forearm. ) Superficialis volse. 1S ' 1 Dorsales pollicis. 



[ Anterior carpal. [ Dorsalis indicia. 



C Princeps pollicis. 



TT -1 Radialis indicis. 

 Hand. ^ -r, ,? , 



Perforating. 



[Interosseous. 



The radial recurrent is given off immediately below the elbow. It ascends 

 between the branches of the musculo-spiral nerve, lying on the Supinator Brevis, 

 and then between the Supinator Longus and Brachialis Anticus, supplying these 

 muscles and the elbow-joint, and anastomosing with the terminal branches of the 

 superior profunda. 



The muscular branches are distributed to the muscles on the radial side of the 

 forearm. 



The superficialis volse arises from the radial artery, just where this vessel is 

 about to wind round the wrist. Running forwards, it passes between the mus- 

 cles of the thumb, which it supplies, and sometimes anastomoses with the termi- 

 nation of the ulnar artery, completing the superficial palmar arch. This vessel 

 varies considerably in size, usually it is very small, and terminates in the mus- 

 cles of the thumb; sometimes it is as large as the continuation of the radial. 



The carpal branches supply the joints of the wrist. The anterior carpal is a 

 small vessel which arises from the radial artery near the lower border of the 

 Pronator Quadratus, and running inwards in front of the radius, anastomoses 

 with the anterior carpal branch of the ulnar artery. From the arch thus formed, 

 branches descend to supply the articulations of the wrist. 



The posterior carpal is a small vessel which arises from the radial .artery be- 

 neath the extensor tendons of the thumb; crossing the carpus transversely tc s 

 the inner border of the hand, it anastomoses with the posterior carpal branch 

 of the ulnar. It sends branches upwards, which anastomose with the termina- 

 tion of the anterior interosseous artery; other branches descend to the meta- 

 carpal spaces; they are the dorsal interosseous arteries for the third and fourth 

 interosseous spaces; they anastomose with the posterior perforating branches 

 from the deep palmar arch. 



The metacarpal (first dorsal interosseous branch} arises beneath the extensor 

 tendons of the thumb, sometimes with the posterior carpal artery; running for- 

 wards on the second dorsal interosseous muscle, it communicates, behind, with 

 the corresponding perforating branch of the deep palmar arch; and, in front, 



