The axillary aery is divided into three pas by

Axillary aery is the continuation of the subclan aery. It extends from the outer border of the first rib to the lower border of the teres major muscle. It continues as the brachial aery. The pectoralis minor muscle crosses it and divides it into three pas. they are - (i) First pa, superior (proximal) to the muscle. (ii) Second pa, posterior (or deep) to the muscle. (iii) Third pa, inferior (distal) to the muscle. Ref : B D Chaurasi's Human Anatomy , seventh edition , volume 1 , pg. no., 50 ( fig. 4.6 )