Iliac Vessels
The aortic bifurcation gives rise to the two common iliac
arteries, which incline down- wards and laterally on the medial aspects of
psoas major (Fig. 4.90).
The vessels terminate in front of the sacroiliac joints by dividing into
internal and external iliac arteries. The right common iliac artery crosses in
front of the left common iliac vein, while that on the left is crossed by the
inferior mesenteric vessels. The ureter crosses
either the lower end of the common iliac artery or the commencement of its
external branch (Fig. 4.90).
The internal iliac artery begins at the bifurcation of the common iliac artery
and descends on the lateral wall of the pelvis (p. 238).
The external iliac artery curves round the pelvic brim (Fig. 4.90) and,
passing behind the inguinal ligament, enters the thigh as the femoral artery
(Fig. 6.19). The external iliac artery is accompanied on its medial side by the
corresponding vein and posterolaterally by psoas major. The external iliac
vessels are crossed by the ovarian vessels in the female and by the ductus deferens
in the male. Near the inguinal ligament the artery gives off the inferior
epigastric artery, which runs upwards and medially, medial to the deep inguinal
ring (Figs 4.18 & 4.23).
Each external iliac vein begins behind the inguinal ligament as
the continuation of the femoral vein (Fig. 4.90). It receives the inferior epigastric
vein, ascends on the medial side of the corresponding artery and joins the
internal iliac vein (p. 145) to form the common iliac vein. The two common
iliac veins continue upwards and medially, passing behind the right common
iliac artery, by which they may be com- pressed, before uniting to form the
inferior vena cava.
