DISSECTION OF THE UPPER LIMB. 



internal, 



external, 



ascending, 



and de- 

 scending. 



Alar tho- 

 racic. 



Long tho- 

 racic. 



External 

 mammary. 



Subscapular 



dorsal 

 branch, 



which give 

 infra- 

 scapular. 



Anterior 

 and 



posterior 

 circumflex. 



Muscular. 



Axillary 

 vein : 



of the artery, which appears at the upper border of the pecto- 

 ralis minor, and opposite the interval between the large pectoral 

 and deltoid muscles. Its principal offsets are directed inwards and 

 outwards : 



a. The inner or thoracic set supply the pectoral muscles, and give 

 a few offsets to the side of the chest, which anastomose with the 

 intercostal and other thoracic arteries. 



b. The outer or acromial set enter the deltoid, and some twigs 

 perforate that muscle to anastomose over the acromion with a branch 

 of the suprascapular artery. 



c. A small clavicular branch ascends to the subclavius muscle. 



d. The humeral branch runs downwards with the cephalic vein 

 between the pectoral and deltoid muscles, to which it is distributed. 



The alar thoracic is very inconstant as a separate branch, its place 

 being frequently taken by offsets of the subscapular and long 

 thoracic arteries ; it is distributed to the glands and fat of the 

 axilla. 



The long thoracic branch is directed along the border of the 

 pectoralis minor to about the fifth intercostal space ; it supplies 

 the pectoral and serratus muscles, and anastomoses, like the other 

 branches, with the intercostal and thoracic arteries. In the female 

 it gives branches to the mammary gland. 



An external mammary artery is frequently met with, especially in 

 the female ; its position is near the middle of the axilla with a 

 companion vein. It supplies the glands, and ends in the wall of 

 the thorax below the long thoracic. 



The subscapular branch courses with a nerve of the same name 

 along the subscapularis muscle, just within the fold of the 

 latissimus dorsi, as far as the lower angle of the scapula, where 

 it ends in branches for the serratus magnus, latissimus dorsi, 

 and teres major muscles. It also gives many off-sets to the 

 glands of the space. 



Near its origin the artery sends backwards a considerable dorsal 

 branch round the lower border of the subscapular muscle, which 

 gives an infrascapular offset to the ventral aspect of the scapula, and 

 then turns to the dorsum of that bone, where it will be afterwards 

 dissected (p. 38). 



The subscapular artery is frequently combined at its origin with 

 other branches of the axillary, or with branches of the brachial 

 artery. 



The circumflex branches wind round the humerus below the sub- 

 scapular muscle. The anterior is small, and passes outwards beneath 

 the coraco-brachialis and biceps, and should be looked for by draw- 

 ing the axillary artery a little away from the coraco-brachialis 

 muscle. The posterior is much larger, and disappears with the 

 companion nerve between the subscapularis and teres major muscles. 

 They will be followed in the dissection of the shoulder. 



Small muscular offsets enter the coraco-brachialis muscle. 



The AXILLARY VEIN (gf) continues upwards the basilic vein of 

 the arm, and has the same extent as the axillarv artery. It lies to 



