The Iliac vein is a name given to three separate veins that drain blood from the pelvic region of humans.
Internal (Hypogastric) Iliac Vein receives blood from the perineal
and pelvic regions of the body. From the pelvis blood drains from the sciatic, gluteal, internal pudic and
obturator veins. In the case of the perineum it receives blood from
the hemorrhoidal and vesicoprostatic plexuses in the male;
vaginal and cervical plexuses in the female.
The External Iliac Vein drains blood from the femoral vein.
The External and Internal Iliac Veins flow into the Common Iliac Vein. The Common Illiac of the right side merges with that of the left.
This union forms the inferior vena cava, which pumps
blood back into the heart to recirculate.
The word Iliac means "of the Ilium". The Ilium is the name for the largest bone in the pelvis, resembling the top half of a butterfly wing. Ilium comes from the Latin for flank.
Blood Flow Chart
Pelvic Veins -> Internal Iliac
-> Common Iliac -> Inferior Vena Cava -> Heart
Femoral Vein -> External Iliac
Gray, Henry. Gray's Anatomy. Crown Publishers, 1977
Marieb, Elaine N. Human Anatomy and Physiology. Sixth Edition. Pearson