THE VASCULAR SYSTEM. 



[49 



vertebral artery and supplying the first and second 

 intercostal spaces, the deep muscles of the back, and 

 the serratus magnus; and the thyroid axis, extend- 

 ing cephalad to supply some muscles of the neck and 

 the lateral aspect of the scapula (Fig. 72). 



The axillary artery gives origin 

 to three branches: the anterior 

 thoracic, the long thoracic, and 

 the circumflex. The anterior tho- 

 racic supplies the pectoral mus- 

 cles. The long thoracic is distrib- 

 uted chiefly to the latissimus 

 dorsi. The circumflex artery is 

 almost as large as the continua- 

 tion of the axillary, which be- 

 yond this point is called the bra- 

 chial. The circumflex, about a 

 centimeter from its origin, after 

 giving off the subscapular, which 

 is distributed mainly to struc- 

 tures in the subscapular fossa, 

 winds around the neck of the 



FIG. 72. ARTERIES OF THE FOREUMB. 

 VENTRAL ASPECT. 



a, Digital artery ; an, anastomotica magna ; 

 ac, anterior circumflex; ai, anterior in- 

 terosseous; ax, axillary; at, anterior 

 thoracic; b, digital artery; be, brachio- 

 cephalic; br, brachial; c, dorsal branch 

 of the radial where it passes between the 

 second and third metacarpals to the 



palmar side; ex, circumflex; is, superior intercostal; Is, left subclavian; 

 It, long thoracic; m, branch to extensor muscles; nt, nutrient; pi, pos- 

 terior interosseous ; r, radial; rd, radial recurrent; sf, supracondyloid 

 foramen of the humerus; spr, superior profunda; sb, subscapularis ; sp, 

 suprascapularis ; st, sternal; th, thyroid axis; ul, ulnar; ur, ulnar recur- 

 rent ; vt, vertebral. 



