UPPER EXTREMITY AND THORAX, POSTERIOR. 371 



found at the back it is covered by the trapezius, levator 

 anguli scapuli, rhomboid muscles. Its course is around 

 the upper angle and along the vertebral border of the 

 scapula to its lower angle. 



It anastomoses, (a) in the supraspinous fossa, with the 

 suprascapular ; ($) in the infraspinous fossa, with the dor- 

 salis scapulae, and (c] at its terminus with the subscapular. 



Its muscular branches supply the adjacent muscles. 



The Suprascapular Artery and Nerve. Fig. 77. 



The artery is one of the branches of the thyroid axis. 

 See page 112. Origin of nerve. See page 315. 



In this part of the dissection it is found passing into the 

 supraspinous fossa over the transverse ligament of the 

 scapula, while the suprascapular nerve passes under it, 

 through the foramen which it forms out of the notch in 

 the scapula. 



The nerve and artery take the same course through the 

 supraspinous fossa and great scapular notch, and terminate 

 in the infraspinous fossa. Both supply the supra- and infra- 

 spinatus muscles and the shoulder joint. 



The artery anastomoses with the posterior scapular in the 

 supraspinous fossa, the dorsalis scapular in the infraspinous 

 fossa, and the acromial branch of the acromiothoracic over 

 the spine and acromial process of the scapula. 



The Dorsalis Scapulae. Fig. 77. 



This large branch from the subscapular (really the con- 

 tinuation of the artery) appears at the back in the triangular 

 interval between the subscapularis above, the teres major 

 below, and the long tendon of the triceps at the outer side, 

 and under cover of the teres minor, between which and 

 the bone it passes into the infraspinous fossa to anastomose 

 with the suprascapular and posterior scapular arteries. 



