133 



ELEMENTS OF MAMMALIAN ANATOMY. 



posite the origin of the vertebral, and extending along the 

 visceral surface of the sternum, and sometimes supplying 

 the pericardium of the heart; the superior intercostal, aris- 

 ing near the vertebral artery and supplying the first and 

 second intercostal spaces, the deep muscles of the back, and 

 the serratus magnus; and the thyroid axis, extending 

 craniad to supply some muscles of the neck and the lateral 

 aspect of the scapula (Fig. 74). 



The axillary artery gives origin to three branches : the 

 anterior thoracic, the long thoracic, and the circumflex. 

 The anterior thoracic supplies the pectoral muscles. The 



long thoracic is distributed chiefly 

 to the latissimus dorsi. The cir- 

 cumflex artery is .almost as large 

 as the continuation of the axillary, 

 which beyond this point is called 

 the brachial. The circumflex, 

 about a centimeter from its ori- 

 gin, after giving off the subscapu- 

 lar, which is distributed mainly to 



FIG. 74. 



ARTERIES OF THE FORELIMB. 

 VENTRAL ASPECT. 



a, Digital artery; an, anastomotica 

 magna; ac, anterior circumflex; ai, 

 anterior interosseous ; ax, axillary ; at, 

 anterior thoracic; b, digital artery; be, 

 innominate ; br, brachial ; c, dorsal 

 branch of the radial where it passes 

 between the second and third meta- 

 carpals to the palmar side ; ex, circum- 

 flex ; is, superior intercostal ; Is, left 

 subclavian; It, long thoracic; m, 

 branch to extensor muscles; nt, nutri- 

 ent ; pi, posterior interosseous ; r, 

 radial; rd, radial recurrent; sf, supra- 

 condyloid foramen of the humerus; 

 spr, superior profunda ; sb, subscapu- 

 laris; sp, suprascapularis ; st, sternal; 

 th, thyroid axis; ul, ulnar; ur, ulnar 

 recurrent ; vt, vertebral. . 



