Blood Vessels

Internal iliac artery - this arises from the bifurcation of the common iliac artery. The internal iliac artery is commonly divided into an anterior division and a posterior division.

1. Anterior division gives off the following branches:

   • Inferior gluteal artery - exits the pelvis via the infrapiriformis recess of the great sciatic foramen (inferior to piriformis muscle). This artery supplies the pelvic diaphragm, piriformis, quadratus femoris, uppermost hamstrings, gluteus maximum, and sciatic nerve.

     1. Internal pudendal artery - exits the pelvis via the infrapiriformis recess of the greater sciatic foramen (inferior to piriformis muscle), enters the perineum via the lesser sciatic foramen, and courses to the urogenital triangle via the pudendal canal. This artery supplies the perineum (main artery of the perineum), including the skin and muscles of the anal triangle and the urogenital triangle and the erectile bodies.

     2. Umbilical artery - runs along the lateral pelvic wall and alongside the bladder for a short distance, then obliterates to form the medial umbilical ligament. The umbilical artery gives rise to the superior vesicle artery, which supplies the superior part of the urinary bladder.

     3. Obturator artery - runs along the lateral pelvic wall and exits the pelvis via the obturator canal. This artery supplies the pelvic muscles, muscles of the medial compartment of the thigh, head of the femur, and ilium.

     4. Vaginal artery (female)/inferior vesicle artery(male) - the vaginal artery in the female supplies the anterior and posterior walls of the vaginal, vestibular bulb, and adjacent rectum. The inferior vesicle artery in the male runs in the lateral ligament of the bladder and supplies the fundus of the bladder, prostrate gland, seminal vesicle, ductus deferens, and lower part of the ureter.

     5. Uterine artery (female)/artery of ductus deferens (male) - the uterine artery runs medially in the base of the broad ligament to reach the junction of the cervix and body of the uterus and runs in front of and above the ureter near the lateral fornix of the vagina. This uterine artery supplies the uterus, ligaments of the uterus, uterine tube, ovary, cervix, and vagina. The artery of the ductus deferens supplies the ductus deferens.

     6. Middle rectal artery - runs medially and descends in the pelvis. It supplies the lower part of the rectum, upper part of the anal canal, prostate gland, and seminal vesicles.

2. Posterior division gives off the following branches:

   • Iliolumbar artery - ascends anterior to the sacroiliac joint and posterior to the psoas major muscle. This artery supplies the psoas major, iliacus, quaratus lumborum, and cauda equina in the vertebral canal.

   • Lateral sacral artery - runs medially in front of the sacral plexus and gives rise to branches that enter the anterior sacral foramina and then emerge from the posterior sacral foramina. It supplies the meninges, roots of the sacral nerves and muscles and skin overlying the sacrum.

   • Superior gluteal artery - exits the pelvis via the suprapiriformis recess of the greater sciatic foramen (superior to the piriformis muscle). It supplies the piriformis, gluteal muscles, and tensor fascia lata.

Median Sacral artery - arises from the posterior aspect of the abdominal aorta and runs close to the midline over the L4 and L5 vertebrae, sacrum, and coccyx. It gives rise to the medial sacral arteries and supplies the posterior part of the rectum, lower lumbar vertebrae, sacrum, and coccyx.

Superior Rectal artery - is a continuation of the inferior mesenteric artery and descends into the pelvis between layers of the sigmoid mesocolon. It supplies the superior part of the rectum.

Ovarian artery (female)/ testicular artery (male) -ovarian artery arises from the abdominal aorta and reaches the ovary through the suspensory ligament of the ovary. This artery supplies the ureter, ovary, and ampulla of the uterine tube. The testicular artery arises from the abdominal aorta and runs in the inguinal canal to enter the scrotum, it supplies the ureter, testis, and epididymis.

Venous Drainage

Pelvic venous plexuses - these plexuses are within the minor (true) pelvis cavity and are formed by intercommunicating veins surrounding the pelvic viscera and include the rectal venous plexus, vesical veonus plexus, prostatic venous plecus, uterine venous plexus, vaginal venous plexus. The pelvic venous plexuses drain venous blood via a number of different pathways as follows:

1. Pelvic venous plexus -> internal iliac veins (join external iliac veins) -> common iliac veins -> IVC

2. Pelvic venous plexus -> median sacral vein -> common iliac vein -> IVC

3. Pelvic venous plexus -> ovarian veins -> IVC

4. Pelvic venous plexus -> superior rectal vein -> IMV -> portal vein

5. Pelvic venous plexus -> lateral sacral veins -> internal vertebral venous plexus -> cranial dural sinuses