A. iliaca communis, common iliac artery. The right and left arteries represent the two terminal branches, into which the aorta splits at the level of the IV lumbar vertebra slightly to the left of the midline, why the right common iliac artery is 6-7 mm longer than the left. From the place of aortic aa split. The iliacae communes diverge at an acute angle (in a man the angle of divergence is approximately 60 °, in a woman due to a greater width of the pelvis 68–70 °) and are directed down and laterally to the sacroiliac joint, at the level of which each is divided into two final branches: a. iliaca interna for the walls and organs of the pelvis and a. iliaca externa mainly for lower limbs.
By origin aa. iliacae communes are the initial segments of the umbilical arteries of the embryo; almost all the rest of the germinal aa. In adults, umbilicales are obliterated and turn into ligg. umbilicalia mediales.