15. Pelvic arteriogram, AP projection
The abdominal aorta bifurcates into the left and right common
iliac arteries anterior to the L4 vertebra. Each of these divides into an
external and internal iliac artery at the pelvic brim over the
sacroiliac joints. The external iliac artery continues around the brim
and enters the lower extremity beneath the inguinal ligament as the femoral
artery. The internal iliac artery descends into the pelvic cavity
and divides into an anterior and a posterior trunk, but beyond this point the
pattern of distribution is quite variable. In general the anterior trunk gives
off both parietal branches (to or through the pelvic wall) — obturator,
internal pudendal, inferior gluteal arteries — and visceral branches
(to the pelvic viscera) — superior and inferior vesical arteries,
middle rectal artery, and either vaginal and uterine arteries
or ductus deferens artery. The posterior trunk gives off only parietal
branches — iliolumbar, lateral sacral, superior gluteal arteries.
