The relations of the femoral and abdominal inguinal rings, seen from within the abdomen. Right side. (External iliac artery is large artery at center, and inguinal ligament runs from upper right to lower left. When the artery crosses the ligament, it becomes the femoral artery.)
The external iliac arteries are two major arteries which bifurcate off the common iliac arteries anterior to the sacroiliac joint of the pelvis. They proceed anterior and inferior along the medial border of the psoas major muscles. They exit the pelvic girdle posterior and inferior to the inguinal ligament about one third laterally from the insertion point of the inguinal ligament on the pubic tubercle at which point they are referred to as the femoral arteries. The external iliac artery is usually the artery used to attach the renal artery to the recipient of a kidney transplant.
The abdominal aorta divides to form the "common iliac arteries" in the lower abdomen, and these vessels supply blood to the pelvic organs, gluteal region, and legs. Each common iliac artery descends a short distance and divides into an internal and an external branch. The external iliac artery provides the main blood supply to the legs. It passes down along the brim of the pelvis and gives off two large branches - the "inferior epigastric artery" and a "deep circumflex artery." These vessels supply blood to the muscles and skin in the lower abdominal wall. The external iliac artery passes beneath the inguinal ligament in the lower part of the abdomen and becomes the femoral artery.
^Tortora, Gerard J.; Grabowski, Sandra R. (2003). Roesch, Bonnie, ed. Principles of Anatomy and Physiology: Volume 4 Maintenance and Continuity of the Human Body (Textbook) 4 (10th ed.). New York, NY: John Wiley & Sons, Inc. p. 734. ISBN0-471-22934-2.