THE ARTERIES 



637 



The ulnar artery doscends on the deep flexor of the digit, and sends a connecting 

 branch to the ra(nal ai)ove the carinis. Xear the middle of the metacarpus it gives 

 off the first volar metacarpal artery and divides into the second, third, and fourth 

 superficial volar metacarpal arteries. The first vohir artery unites with the cor- 

 responiHiig dorsal arter>- to form the first common digital artery, which supplies 

 proper digital arteries for the opposed surfaces of the first and second digits. The 

 superficial volar arteries descend in the spaces between the other metacarpal bones, 

 unite near the metacarpo-phalangeal joints with the corresponding deep volar and 

 dorsal metacarpal arteries to form three common digital arteries. Each of the latter 



Fig. 489. — Arteries of Distal Part of Right Forp. 

 Limb of Dog, Anterior View. 

 a, Branch of volar interosseous artery; 6, 

 proximal collateral radial artery (external branch) ; 

 c, radial artery (tlorsal branch); d, rete carpi dorsale; 

 e, deep dorsal metacarpal arteries; /, sujjerficial dorsal 

 metacarpal arteries; </, common digital arteries; h, 

 proper digital arteries. 



Fig. 490. 

 i, Radial artery; j, ulnar artery; k, volar in- 

 terosseous artery; /.deep volar arch; m, external (fifth) 

 volar metacarpal artery; n, deep volar metacarpal 

 arteries; p. superficial volar metacarpal arteries; o, 

 q, common digital arteries; r, proper digital arteries. 



divides after a short course into two proper digital arteries, which run along the 

 opposed surfaces of the second to the fifth digits. The external digital artery of 

 the fifth digit comes from the superficial volar arch formed by the union of 

 a branch of the volar interosseous with the fourth superficial volar metacarpal 

 artery. 



The rete carpi dorsale gives off four dorsal metacarpal arteries which descend 

 in the intermetacarpal spaces and unite near the metacarpo-phalangeal joints with 

 the volar arteries to form the common digitals. 



The thoracic aorta supplies the last nine or ten pairs of intercostal arteries, 

 but no anterior phrenic arteries. It gives off two or more oesophageal branches, in 



