The internal iliac artery (also known as the hypogastric artery) is the smaller terminal branch of the common iliac artery. It supplies the pelvic walls, pelvic viscera, external genitalia, perineum, buttock and medial part of the thigh.
Gross anatomy
Origin
The common iliac artery bifurcates into the internal iliac artery and external iliac artery at the level of the pelvic brim anterior to the sacroiliac joint.
Course
The internal iliac artery courses posteromedially towards the greater sciatic foramen. It is approximately 4 cm in length.
At the superior margin of the greater sciatic foramen it divides into an anterior division and posterior division. The anterior division continues down to the ischial spine anterior to piriformis giving off visceral and parietal branches. The posterior division only gives rise to parietal branches.
Branches
Anterior division
umbilical artery (only patent in the fetus)
superior vesical artery (branch of the umbilical artery)
obturator artery (25% will branch off the inferior epigastric artery)
vaginal artery
inferior vesical artery
uterine artery
middle rectal artery
internal pudendal artery (supplies the external genitalia)
inferior gluteal artery
The obturator, internal pudendal and inferior gluteal arteries are parietal branches, whereas the other arteries in the above list are visceral arteries (i.e. umbilical, superior and inferior vesical, vaginal, uterine and middle rectal artery).
The nine branches of the anterior division of the internal iliac artery may be more easily remembered in these divisions:
"three urinary": umbilical artery, superior vesical artery, inferior vesical artery
"three visceral": uterine artery, vaginal artery, middle rectal artery
"three parietal": obturator artery, internal pudendal artery, inferior gluteal artery
Posterior division
iliolumbar artery
lateral sacral arteries
superior and inferior branches
superior gluteal artery