The anterior intercostal aeries anastomose with the posterior intercostal aeries. Ligation of the anterior aeries would not affect the supply of the intercostal spaces because the posterior aeries would provide collateral aerial supply. Branches of the musculophrenic aery provide supply for the lower seventh, eighth, and ninth intercostal spaces. The superior epigastric aery passes into the rectus sheath of the anterior abdominal wall. The lateral thoracic aery arises from the second pa of the axillary aery, and the thoracodorsal aery is a branch of the subscapular aery, a branch of the third pa of the axillary aery