The subscapular artery is the largest branch of the distal part of the axillary artery. It runs inferiorly at the posterior axillary wall, following the lateral margin of the subscapularis muscle. The artery terminates by dividing into two terminal branches: thoracodorsal and circumflex scapular arteries. Both terminal branches participate in the formation of anastomoses in the scapular region.
The main function of the subscapular artery is to provide blood supply for the muscles and skin of the shoulder, upper extremity and thoracic wall. The supplied muscles include the deltoid, latissimus dorsi, long head of triceps brachii, subscapularis, supraspinatus, infraspinatus and serratus anterior muscles.
|Branches||Thoracodorsal artery, circumflex scapular artery|
|Supply||Deltoid muscle, latissimus dorsi muscle, long head of triceps brachii muscle, subscapularis muscle, supraspinatus muscle, infraspιnatus muscle, serratus anterior muscle, adjacent skin|
This article will discuss the anatomy and function of the subscapular artery.
The subscapular artery is the first branch of the third segment of the axillary artery. It arises after the lateral thoracic artery at the level of the inferior margin of the subscapularis muscle. The subscapular artery runs inferolaterally on the posterior axillary wall, following the lateral border of the subscapular muscle. It terminates by dividing into two terminal branches: the thoracodorsal and circumflex scapular artery.
The subscapular artery forms anastomoses with the suprascapular artery, the dorsal scapular artery and the intercostal arteries.
Branches and supply
Due to the large diameter of the artery and its terminal branches, the subscapular artery supplies numerous muscles of the shoulder region. These include:
- Deltoid muscle
- Latissimus dorsi muscle
- Long head of triceps brachii muscle
- Subscapularis muscle
- Supraspinatus muscle
- Infraspinatus muscle
- Serratus anterior muscle
The subscapular artery provides two large terminal branches: the circumflex scapular and thoracodorsal arteries.
- The circumflex scapular artery is the larger of the two terminal branches. It runs posteriorly, wraps around the lateral margin of scapula and emerges on the posterior surface of the scapula. This branch supplies the teres major and subscapularis muscle. It provides collateral branches that participate in the formation of the scapular arterial anastomoses.
- The thoracodorsal artery runs inferoposteriorly along the lateral border of the scapula. On its course, this artery gives rise to small branches that supply the latissimus dorsi muscle and the adjacent skin.
Learn more about the main arteries of the upper limb with our articles, videos, labeled diagrams and quizzes.
- The subscapular artery can occasionally arise from the second part of the axillary artery which is the part of the artery posterior to the pectoralis minor muscle (in about 15% of cases). This artery can also be absent in which case the terminal branches arise individually from the axillary or lateral thoracic arteries.
- The subscapular artery can also give rise to additional branches, for example, the lateral thoracic or the posterior circumflex arteries.