Axillary aery is divided into three pas by?

Axillary aeryIt is the main aery of upper limb. It begins at the level of outer border of first rib as a continuation of subclan aery. It ends at the level of lower border of teres major to continue as brachial aery.The axillary aery is covered anteriorly by pectoralis minor, which divides it into three pas:?1) First pa :- This pa is proximal to upper border of pectoralis minor, i.e. extends from outer border of first rib to upper border of pectoralis minor. The branch of first pa is Superior thoracic aery.2) Second pa :- This pa is behind pectoral is minor. It gives following branches.A) Thoracoacromial aery :- It pierces clavipectoral foscia and gives following branches :-(i) Acromial (ii) Pectoral, (iii) Clavicular and deltoid.B) Lateral thoracic aery3) Third pa :- This pa is distal to lower border of pectoralis minor, i.e. extends from pectoralis minor (lower border) to teres major (lower border). It gives following branches ?A) Subscapular aery:- It gives off circumflex scapular aery and then continues us thoracodorsal aery.B) Anterior circumflex humeral aery.C) Posterior circumflex humeral aery.Anterior and posterior circumflex aeries (both are branches of 3rd pa of axillary aery) forms anastomosis around surgical neck of humerus.