Axillary artery and its branches--anterior view of right upper limb and thorax. Upper and lower limits labeled.
The pectoralis minor muscle is used as a landmark for dividing the axillary artery into three parts.
Anterior circumflex humeral
Posterior circumflex humeral
continues as brachial artery
In human anatomy, the axillary artery is a large blood vessel that conveys oxygenated blood to the lateral aspect of the thorax, the axilla (armpit) and the upper limb. Its origin is at the lateral margin of the first rib, before which it is called the subclavian artery.
The axillary artery is often referred to as having three parts, with these divisions based on its location relative to the Pectoralis minor muscle, which is superficial to the artery.
The axillary artery is accompanied by the axillary vein, which lies medial to the artery, along its length.
In the axilla, the axillary artery is surrounded by the brachial plexus. The second part of the axillary artery is the reference for the locational descriptions of the cords in the brachial plexus. For example, the posterior cord of the brachial plexus is so named because it lies posterior to the second part of the artery.
The axillary artery has several smaller branches. The branches can be remembered, in order, when traveling from the heart, with the mnemonics "Screw The Lawyers Save A Patient", "Summertime: The Lakers Schedule Another Parade", "Sixties Teens Love Sex And Pot", or "She Tastes Like Sweet Apple Pie." The origin of these branches is highly variable (e.g. the posterior and anterior circumflex arteries often have a common trunk). An arterial branch is named for its course, not its origin.
The axillary artery can be safely clamped without endangering the arm, but only in a location proximal to the origin of the subscapular artery (and distal to the thyrocervical trunk of the subclavian artery). The anastomotic network surrounding the scapula provides an alternate path for collateral circulation to the arm from arteries including the dorsal scapular artery and suprascapular artery.