the continuation of the subclavian artery after crossing the first rib to enter the axilla; becomes the brachial artery upon passing the inferior border of the teres major muscle. It is accompanied by the cords of the brachial plexus, and is enclosed with them and the axillary vein in the axillary sheath as it traverses the axilla. The parts of the axillary artery are described: proximal, posterior and distal to the pectoralis minor muscle. Branches: 1st partsuperior thoracic artery; 2nd partthoracoacromial arterial trunk, lateral thoracic artery; 3rd partsubscapular artery, anterior and posterior humeral circumflex arteries. Syn: arteria axillaris [NA].