THE POSTERIOR RADIAL ARTERY 



561 



2. Muscular branches to the flexors of the carpus and digit. The largest of 

 these arise at the proximal third of the forearm. 



3. The common interosseous artery (A. iuterossea communis) is a vessel of 



Artery of rate carpi voiarc 



Oblique ligament 



Internal lateral lig. 

 First carpal bone 



Deep volar metacarpal arteries 

 Int. metacarpal bone 



Radius 



A ccessorio-radial lig. 

 Accessorio-ulnar lig. 



E External lateral lig. 

 Cheek ligament 



Accessorio-metacarpal lig. 

 Deep volar arch 

 S uspe n sory I iga in e nt 

 Ext. metacarpal bone 



Fig. 444. — Deep Dissection of Right C.\ri>is of Horse, Posterior View. 

 1, Radial carpal bone; 2, accessory carpal bone; S, second carpal bone. (After Schmaltz, Atlas d. Anat. d. Pferdes.) 



considerable size which arises at the level of the interosseous space, through which 

 it passes. Before entering the space it gives off a small l)ranch, the volar interos- 

 seous (A. interossea volaris), which descends to the ratlial head of the perforans. 

 In the space it supplies the nutrient arteries of the radius and ulna. Emerging 



Cutaneous branch of musculo- 

 cutaneous nerve 

 Tendon of extensor carpi obliquus 



Lateral ligament 



Tendon of extensor carpi radialis 

 Tendon of anterior dig. extensor 



Skin 



Lateral ligament 



Tendon of lateral dig. extensor 



Tendon of deep dig. flexor 

 Tendon of superficial dig. flexor 

 Long tendon of flex, carpi externus 

 Superficial branch of ulnar nerve. 



Tendon of flex, carpi inter nus 



Int. metacarpal rein 



hit. volar or .small met. artery 



Common dig. or large met. artery 



Posterior annular ligament 



Internal metacarpal nerve 



External metacarpal vein 



External metacarpal nerve 



External volar met. artery 



Fig. 445. — Cross-section of Right Carpus of Horse. 

 The soft structures are cut at the level of the radio-carjjal articulation, exposing the proximal row of carpal 

 bones. Cr, Radial carpal bone; Ci, intermediate carpal bone; Cu, ulnar carpal bone; Ca, accessory carpal bone. 

 (After Schmaltz, Atlas d. Anat. d. Pferdes.) 



from the space it gives ofT branches to the flexor carpi externus, a small recurrent 

 branch (A. interossea recurrens) which passes upward on the outer surface of the 

 ulna and anastomoses with the deep brachial and ulnar arteries, and is continued 

 36 



