262 



APPLIED ANATOMY. 



Externally is the coracobrachial muscle (which partly overlaps it and forms its 



guide), the main trunk and outer head of the median, and the musculocutaneous nerves. 



Internally is the axillary vein with the ulnar nerve between it and the artery. 



The internal and lesser internal cutaneous nerves also lie to its inner side with the 



former the more anterior. 



Ligation of the Third Portion of the Axillary Artery. The arm being 

 placed out from the body, palm upward, the incision for ligating the axillary artery in 

 the third portion of its course is laid along the inner border of the coracobrachial 

 muscle, at about the junction of the anterior and middle thirds of the axilla and on a 

 line joining the middle of the clavicle and a point at the bend of the elbow midway 

 between the two condyles of the humerus. 



The middle of the incision should be just above the lower edge of the folds of 

 the axilla. The deep fascia having been opened, the coracobrachial muscle with the 



musculocutaneous nerve piercing it is 

 pulled outward. Lying on the artery 

 to its outer side is the median nerve; 

 it is to be drawn outward. To the 

 inner side lies the axillary vein with 

 the ulnar nerve beneath it and the 

 internal cutaneous nerve (cutaneus 

 antebrachii medialis) in front of it 

 close to the artery. 



The needle is passed from within 

 outward. The artery at this point may 

 be crossed by some muscular fibres 

 coming from the latissimus dorsi and 

 crossing the axilla. The axillary vein 

 is the continuation of the basilic from 

 the lower border of the teres major 

 upward. 



Of the two venae comites of the 

 brachial artery the inner one blends 

 with the basilic at the lower border 

 of the teres major; the outer one 

 crosses the artery to empty into the 



Acromiothoracic 



Posterior circumflex 

 Anterior circumflex 

 Subscapular 



Alar thoracic 



Superior profunda (arteria 

 profunda brachii) 



Brachial artery 



FIG. 274. Collateral circulation after ligation of the third 

 portion of the axillary artery. 



axillary vein on the opposite side. 



The axillary vein receives the 

 subjjCapular, circumflex, long thoracic, 

 acromiothoracic, alar, and cephalic, 



and contains a pair of valves opposite the lower border of the subscapularis muscle. 

 Collateral Circulation after Ligature of the Axillary Artery. If the 

 first portion of the axillary is tied, the acromiothoracic artery comes off so low down 

 (under the edge of the pectoralis minor muscle almost) that the ligature is placed 

 above it, in which case the collateral circulation is similar to that of the subclavian 

 (see page 149). The second portion of the axillary, lying beneath the pectoralis 

 minor, is not subject to ligation. In the third portion the subscapular and anterior 

 and posterior circumflex arteries come off so close together that the ligature will be 

 placed either just below or just above them (Fig. 274). 



If below, then the collateral circulation will be between them above and the 

 superior profunda below. If above the subscapular, then the anastomosis would be 

 as follows: 



PROXIMAL VESSELS. DISTAL VESSELS. 



Acromiothoracic, acromial branch with anterior and posterior circumflex 



Acromiothoracic, humeral branch with anterior and posterior circumflex 



Acromiothoracic, pectoral branch with subscapular 



Long thoracic branch . with subscapular 



Alar thoracic branch with subscapular 



Posterior scapular (branch of trans, cervical) with subscapular and dorsalis scapulae 



Suprascapular with dorsalis scapulae and posterior 



circumflex 



