406 



Arteries of the Neck and Arm. 



3. A. mammaria interna (continued): 



h) A. musculophrenica, extends behind the cartilages of the T^h lO^h (or 11 1^) rib, just 

 over the origins of the pars costalis of the diaphragm, lateralward and downward; it 

 gives off 7'ami intercostales for the 7*^ 10th (or 11^^) intercostal space and is 

 distributed also in the diaphragm and in the abdominal muscles. 



i) A. epigastrica superior, passes between the processus xiphoideus and the 7th costal 

 cartilage forward into the substance of the m. rectus abdorainis,_runs downward in this and 

 anastomoses in the region of the navel with the a. epigastrica inferior; it gives off 

 several small branches wbieh go forward to the skin in the neighborhood of the navel. 



4. Truucus costocervicalis (see also Figs. 441 and 461), from the posterior wall, di- 

 vides after a short, upward course into two terminal branches: 



a) A. cervicalis profunda (deep cervical artery), backward between the l^t rib and the 



jiroc. transversus of the 7tli cervical vertebra, runs upon the m. semispinalis cervicis as 

 far as the epistropheus. It supplies the muscles of the neck and, by a descending 

 branch, the long muscles of the back ; several branches into the intervertebral foramina. 



b) A. iniercostalis suprema (first intercostal artery) bends doi;\Tiward and backward in front 



of the neclc of the first rib to the l^t intercostal space and also usually in front of the neck 

 of the 2"d rib to the 2"d intercostal space. It gives oft" rami posteriores to the muscles 

 and skin of the back and rami spinales into the foramina intervertebraUa ; in these 

 branches and in its further course it behaves quite hke the aa. intercostales (see p. 419). 



5. A. transversa colli (0. T. transverse cervical artery or transyersalis colli) (see Figs. 

 449 and 452), from the upper wall of the ST'sulicla^ia, runs among the branches of the plexus 

 brachialis, 'directly upon the lateral surface of the m. scalenus medius, lateralward and back- 

 ward and divides beneath the m. levator scapulae into its two terminal branches. It gives off 

 a branch to the fossa supraspinata and supplies the muscles in the neighborhood of the same. 



a) Ramus ascendens, extends upward between the m. levator scapulae and the mm. splenii 



in the neck to supply these muscles. 



b) Ramus desce/ideiis, passes "downward between the mm. rhomboidei and the m. serratus 



posterior superior along the margo vertebralis of the scapula; it supplies these and 

 the adjacent muscles and sends branches to the skin. 



A. axillaris (axillary artery) (see Figs. 434, 449 and 451) runs distalward from 

 the lower margin of the m. subclavius along the lateral angle of the axilla ; it is covered at 

 first by the proc. coracoideus, then lies in the groove behind the m. coracobrachialis and is 

 bounded behind by the mm. subscapularis, latissimus dorsi and teres major, medianward by the 

 m. serratus anterioi-. Superficially (in front and mediauMard) it is covered by the v. axillaris ; 

 on the lateral, posterior and inferior and partially also on the anterior surface it is directly 

 surrounded by the long branches of the plexus brachialis. From the lower margin of the m. 

 pectoralis major on, its continuation is called the a. brachialis. Besides small branches to the 

 m. subscai)ularis, ia7ni subscapulares, it gives off the following branches: 



1 . A. thoraealis suprema (0. T. superior thoracic artery)(not illustrated) arises behind the 

 m. subclavius and runs downward, partly in front of and partly behind the m. pectoralis minor to 

 the muscles of the chest ; it is usually absent and substituted by a branch of the a. thoracoacromialis. 



2. A. thoracoacromialis (0. T. acroraiothoracic or thoracic axis) (see Figs. 434, 449 

 and 451) arises at the up})er margin of the m. pectoralis minor and ends in rami pectorales 

 between the muscles of the chest. Branches : 



a) Ramus acromialis, transversely beneath the mm. pectoralis major and deltoideus, inft-ont 



of the proc. coracoideus, lateralward, supplies these muscles, perforates the m. deltoideus 

 and ends in the retc acromiale, situated upon the upper surface of the acromion. 



b) Ramus deltoideus goes downward in tbe slit between the mm. pectoralis major and 



deltoideus; it su})plies especially the latter muscle and the skin over it. 



3. A. thoraealis lateralis (0. T. long thoracic artery) (see Fig. 449 and 451) arises 

 behind the m. pectoralis minor and runs upon the m. serratus anterior downward as far as the 

 5th or fi'h intercostal space ; it supplies (^specially the m. serratus anterior. Several branches 

 [rami mammarii extend) go through the m. pectoralis major to the skin of the mannnary region. 



4. A. subscapularis (see Figs. 451 and 452), arises at the lower margin of the m. 

 subscapularis, goes downward and soon divides into two terminal branches: 



a) A. circumflexa scapulae (0. T. dorsalis scapidae), bends backward between the mm. sub- 



scapularis and teres major and then, medial from the caput longum of the m. triceps, 

 goes upward, ])artly in front of, partly behind the m. teres minor, into the fossa 

 infras})inata. It su]ij)lies the neighboring muscles and skin and anastomoses freely 

 with file a. transversa sca])ulae. 



b) A. tlwracodorsalis, between the mm. latissimus dorsi and serratus anterior along the margo 



axillaris scapulae downward and backward, supplies the neighboring muscles and skin. 



