Internal iliac artery
Arteria iliaca interna
Also known as: hypogastric artery
The internal iliac artery is the main artery of the pelvis. It arises from the common iliac artery at the pelvic brim and divides into anterior and posterior divisions, which supply the pelvic organs, the perineum, the buttock and the medial thigh.
Overview
The internal iliac artery is about 4 cm long. It runs down into the pelvis toward the upper edge of the greater sciatic foramen, where it divides.
Posterior division. This supplies the pelvic wall and the buttock. Its branches are the iliolumbar artery, the lateral sacral arteries and the superior gluteal artery, its largest branch. The superior gluteal artery leaves the pelvis above piriformis.
Anterior division. This supplies the pelvic organs, the perineum and some muscles. The umbilical artery stays open in its first part, which gives the superior vesical arteries. The rest of it closes after birth and becomes the medial umbilical ligament. The division also gives the obturator artery, the inferior vesical artery (in men) or vaginal artery (in women), the artery to the ductus deferens and the middle rectal artery.
The uterine artery crosses above the ureter on its way to the uterus. The internal pudendal artery leaves the pelvis below piriformis and re-enters the perineum through the lesser sciatic foramen. It supplies the external genitalia, including the erectile tissue. The last branch is the inferior gluteal artery.
Anatomy
- Branches
Posterior division: the iliolumbar, lateral sacral and superior gluteal arteries. Anterior division: the umbilical (and superior vesical), obturator, inferior vesical or vaginal, middle rectal, uterine, internal pudendal and inferior gluteal arteries.
Function
- Supplies the bladder, rectum, internal genital organs, perineum and external genitalia.
- Supplies the gluteal muscles, the pelvic wall and the hip adductors (through the obturator artery).
- In the fetus, gives rise to the umbilical arteries.
Clinical significance
Pelvic haemorrhage
Pelvic fractures can tear branches of the internal iliac artery, most often the superior gluteal, internal pudendal and obturator arteries. Bleeding can be life-threatening and is controlled by angiographic embolisation or pelvic packing.
Water under the bridge
The uterine artery crosses above the ureter ("water under the bridge") near the cervix. The ureter is at risk when the uterine artery is clamped during hysterectomy.
Corona mortis
An abnormal connection between the obturator artery and the inferior epigastric or external iliac artery crosses the superior pubic ramus. It is called the "corona mortis" ("crown of death") because it can bleed heavily during hernia repair or pelvic fracture fixation.
Mnemonics
Branches
"I Love Going Places In My Very Own Underwear": Iliolumbar, Lateral sacral, Gluteal (superior and inferior), internal Pudendal, Inferior vesical (or vaginal), Middle rectal, Vesical (superior), Obturator, Umbilical (and Uterine).
Compiled from standard anatomy and physiology references — see the Cardiovascular System sources. For education only; not medical advice.