390 



THE SUBCLAVIAN ARTERY. 



When the siiperficial cervical is separated from the posterior scapular, it some- 

 times arises from other sources than the thyroid axis, as from the suprascapular 

 or the subclavian artery. 



Fig. 25S. 



i^^''%'^. ' . 



Fig. 258. — Dissection of the eight side 



OF THE ANTERIOR ThORACIC AND AB- 

 DOMINAL Wall, to show the Anasto- 

 moses OF THE Internal Mammary. 

 Intercostal, and Epigastric Vessels 

 (slightly altered from Tiedemann), 

 (A. T.) \ 



The pectoral part of the serratus mag- 

 niis, the external and internal oblique,, 

 and the rectus abdominis muscles, have 

 been removed ; 1, upon the subclavius 

 muscle, points to the first part of the 

 axillary artery above the pectoralis minor 

 muscle, giving rise to the acromio-thoracic 

 artery, which is cut short ; 2, upon the 

 pectoralis minor, points to the lower part 

 of the axillary artery and vein ; 3, the 

 long thoracic artery ; 4, on the cartilage of 

 the first rib, marks the upper part of the 

 internal mammary artery ; 4', the lower 

 part of the same artery giving its abdominal 

 branch behind the cartilage of the seventh 

 rib ; 5, in the fourth intercostal space, 

 marks the anastomosis of the internal 

 mammary and intercostal arteries ; 6, 

 anterior branches of the internal mam- 

 mary artery ramifying over the front of the 

 sternum ; 7, on the transversalis muscle 

 immediately above the internal inguinal 

 aperture, points to the last part of the ex- 

 ternal iliac artery, from which are seen 

 rising, 8, the deep epigastric artery, and 

 9, the deep circumflex iliac ; 10, the anas- 

 tomosis of the epigastric with the abdomi- 

 nal branch of the internal mammary 

 artery ; 11, the spermatic cord and sper- 

 matic twig of the epigastric artery ; 12, 

 the femoral artery ; lo, the femoral vein ;. 

 14, a lymphatic gland closing the femoral 

 ring. 



3. — Internal Mammary Ar- 

 tery. — The internal mammary 

 artery, remarkable for its length 

 and the number of its branches, 

 arises from the under side of the ■ 

 subclavian, opposite the thyroid 

 axis. It runs forwards and down- 

 wards behind the clavicle to the 

 inner surface of the cartilage of 

 the first rib, lying between this 

 and the sac of the pleura : from 

 this point it inclines a little inwards, and then descends vertically 

 behind the costal cartilages, a sho t distance from the border of the 

 sternum, as fixr as to the interval between the sixth and seventh 

 cartilages, where it ends by dividing into two branches. One of the 



