The lateral pectoral nerve originates from the anterior aspect of the lateral cord, also known in anatomical terminology as lateral fascicle, at the level of the first portion of the axillary artery. It gives off one or more branches which perforate the clavipectoral fascia to innervate the clavicular portion of pectoralis major (C5, C6, and C7). It gives off an inferior branch which joins the medial pectoral nerve to form the ansa pectoralis to innervate the sternocostal part of pectoralis major. The medial pectoral nerve originates from the anterior aspect of the medial cord, also known in anatomical terminology as medial fascicle, at the level of the first portion of the axillary artery, behind it. From here, it curves passing between the axillary artery and vein to form the ansa pectoralis localized in the second portion of the axillary artery just distal to the thoracoacromial artery (landmark). It innervates pectoralis minor, perforates it, and ends in pectoralis major.