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.
Anterior circumflex humeral
Posterior circumflex humeral
continues as brachial 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.
- First part – the part of the artery superior to the pectoralis minor
- Second part – the part of the artery posterior to the pectoralis minor
- Third part – the part of the artery inferior to the pectoralis minor.
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.
- First part (1 branch)
- Second part (2 branches)
- Thoraco-acromial artery
- Lateral thoracic artery. If the lateral thoracic artery is not branching from the axillary artery, will most likely branch from the following (in order of likelihood): (1) thoracoacromial, (2) third part of axillary artery, (3) suprascapular artery, (4) subscapular artery
- Third part (3 branches)
Clinical significance edit
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.
Additional images edit
The veins of the right axilla, viewed from in front.
The right brachial plexus (infraclavicular portion) in the axillary fossa; viewed from below and in front.
Suprascapular and axillary nerves of right side, seen from behind.
Brachial plexus and axillary artery
- lesson3axillaryart&vein at The Anatomy Lesson by Wesley Norman (Georgetown University)
- Axillary artery at the Duke University Health System's Orthopedics program
- Anatomy photo:05:06-0101 at the SUNY Downstate Medical Center – "Axillary Region: Parts of the Axillary Artery"
- Anatomy figure: 05:04-01 at Human Anatomy Online, SUNY Downstate Medical Center – "The axillary artery and its major branches shown in relation to major landmarks."