Begin identification of the major components of the axillary region. First identify some important vascular structures. The majority of these vessels can be found either in the axilla or very close to it. The axillary artery begins at the lateral edge of the first rib and runs to the inferior edge of the teres major. Now find two of the major branches of the axillary artery. The more proximal branch, the thoracoacromial artery , comes off the axillary artery medial to the superior edge of the pectoralis minor. The branches of this "trunk" supply the pectoral and superior regions of the shoulder. The more distal branch, the subscapular artery , comes off the axillary artery inferior to the pectoralis minor and heads inferiorly along the posteriolateral wall of the axilla. (Figure 11-2)

At the inferior border of the teres major, the axillary artery continues as the brachial artery . The brachial artery runs to a point slightly proximal to the elbow.

Figure 11-2
Arterial supply of the shoulder region.

The deep brachial or profunda brachii artery is the only major branch of the brachial artery. It arises from the brachial artery slightly distal to the teres major muscle. This artery normally courses distally in a posterior lateral direction, and is usually accompanied by the radial nerve. (Figure 11-2)