AXILLARY 



525 



The dorsal scapular, arisiiiu; from the siil)seapular, usually at the ahove- 

 mentioned spot, passes hackwards throu^di the triangular spaee bounded by the sub- 

 scapularis above, the teres major l)elo\v, and the long head of the triceps externally, 

 and then between the teres minor and the axillary border of the scapula, which "it 

 connnonly grooves. It thus reaches the infraspinous fossa, Avhere, under cover of 

 the infraspinatus, it anastomoses with the suprascapular and posterior scapular 

 arteries (tig. 347). As it passes througli the triangular s})ace, it gives off a ventral 

 branch, sometimes called the infrascapular, which ramifies between the subscapu- 

 laris and the bone, supplying branches to the subscapularis, to the scapula, and 

 to the shoulder-joint. A second branch is often given off near the triangular space 

 and passes downwards between the teres major and teres minor, supplying both 

 muscles (fig. 348). 



The chief variations in the subscapular artery are: — (a) It niaj- come off witli the posterior 

 circuiuflex; (Z>) it iiiaj' arise from a trunk commou to several other of the branches of the third 



Fig. 349. — The Anastomoses about the Scapula. 



Subscapiilar branch of snpraseiijiular artery 

 Siipraspinovs hrnnch of suprascapular artery 



Posterior scapular arlr 



Supraspinous hranrli 

 uf posterior scapulur 

 artery 



Suhscapti/ar branch 

 of posterior scapulur 

 artery 



Branch of intercostal 

 artery 



Branch of intercostal 

 artery 

 < 'ontimtalion of posterior 

 scapulur artery 



Suprascapular artery 



Acromial branch 

 of ucromio- 

 tlioracic 



Acromial rete 



Subscapular branch 



of suprascapular 



artery 

 Infraspinous branch 



of suprascapular 



artery 

 Subsiiipiilar branch 



<f axillary artery 



Dorsal scapular branch of 

 subscapular artery 



Iiifrasciijiulur branch if 

 dorsal scapular artery 



Continuation of sub- 

 senpular artery 



part of the axillary artery and upjier pavt of the brachial artery ; and (c) its dorsal scapular 

 hranch may arise from the axillary direct. 



2. The anterior circumflex, usually quite a small vessel, comes ofif from the 

 outer .side of the axillary artery, generally opposite the posterior circumflex. It 

 passes beneath the coraco-brachialis and short and long heads of the biceps, wind- 

 ing transversely round the front of the surgical neck of the linmerus, across the 

 bicipital groove, and anastomoses with the posterior circumflex and acromial 

 thoracic arteries. It gives off the following small branches: (n) the bicipital or 

 ascending, which runs up the bici|)ital groove to sup])ly the long tendon of the 

 biceps and the shouhler-joint; and (h) a pectoral or descending branch, which 

 runs downwards along the insertion of the pectoralis major, and supplies the tendon 

 of that muscle. The anterior circumflex artery, in conse(|Uence of its being close 



