582 



A NG 10 LOGY 



Desc. br. o/ 

 transverse cervical 



Transverse scapular 



Acromial branch 

 of tkoracoacromial 

 I 



FIG. 521. The scapular and circumflex arteries. 



The Transverse Scapular Artery (a. transversa scapula; suprascapular artery) passes 

 at first downward and lateralward across the Scalenus anterior and phrenic 



nerve, being covered by the 

 Sternocleidomastoideus; it then 

 crosses the subclavian artery 

 and the brachial plexus, and 

 runs behind and parallel with 

 the clavicle and Subclavius, 

 and beneath the inferior belly 

 of the Omohyoideus, to the 

 superior border of the scapula; 

 it passes over the superior 

 transverse ligament of the 

 scapula which separates it from 

 the suprascapular nerve, and 

 enters the supraspinatous fossa 

 (Fig. 521). In this situation it 

 lies close to the bone, and rami- 

 fies between it and the Supra- 

 spinatus, to which it supplies 

 branches. It then descends be- 

 hind the neck of the scapula, 

 through the great scapular 

 notch and under cover of the 

 inferior transverse ligament, to 

 reach the infraspinatous fossa, where it anastomoses with the scapular circumflex 

 and the descending branch of the transverse cervical . Besides distributing branches 

 to the Sternocleidomastoideus, Subclavius, and neighboring muscles, it gives off a 

 suprasternal branch, which crosses over the sternal end of the clavicle to the skin of 

 the upper part of the chest; and an acromial branch, which pierces the Trapezius 

 and supplies the skin over the acromion, anastomosing with the thoracoacromial 

 artery. As the artery passes over the superior transverse ligament of the scapula, 

 it sends a branch into the subscapular fossa, where it ramifies beneath the Sub- 

 scapularis, and anastomoses with the subscapular artery and with the descending 

 branch of the transverse cervical. It also sends articular branches to the acro- 

 mioclavicular and shoulder-joints, and a nutrient artery to the clavicle. 



The Transverse Cervical Artery (a. transversa colli; transversalis colli artery) lies 

 at a higher level than the transverse scapular; it passes transversely above the 

 inferior belly of the Omohyoideus to the anterior margin of the Trapezius, beneath 

 which it divides into an ascending and a descending branch. It crosses in front of 

 the phrenic nerve and the Scaleni, and in front of or between the divisions of the 

 brachial plexus, and is covered by the Platysma and Sternocleidomastoideus, and 

 crossed by the Omohyoideus and Trapezius. 



The ascending branch (ramus ascendens; superficial cervical artery) ascends be- 

 neath the anterior margin of the Trapezius, distributing branches to it, and to the 

 neighboring muscles and lymph glands in the neck, and anastomosing with the 

 superficial branch of the descending ramus of the occipital artery. 



The descending branch (ramus descendens; posterior scapular artery) (Fig. 521) 

 passes beneath the Levator scapulae to the medial angle of the scapula, and then 

 descends under the Rhomboidei along the vertebral border of that bone as far as 

 the inferior angle. It supplies the Rhomboidei, Latissimus dorsi and Trapezius, 

 and anastomoses with the transverse scapular and subscapular arteries, and with 

 the posterior branches of some of the intercostal arteries. 



