ARTERIES OF THE PELVIC LIMB 673 
through the greater sciatic foramen, dividing into several branches as it emerges; 
these enter the gluteal muscles (Fig. 580). 
6. The iliaco-femoral or lateral circumflex artery of the thigh (A. circumflexa 
femoris lateralis) passes ventro-laterally across and beneath the shaft of the ilium, 
under cover of the iliacus muscle, and dips in between the rectus femoris and vastus 
lateralis. It is accompanied by two satellite veins. It gives collateral branches to 
the iliopsoas, the glutei, and the tensor fascize late, supplies the nutrient artery of 
the ilium, and terminates in the quadriceps femoris (Fig. 580). 
7. The obturator artery (A. obturatoria), the medial terminal branch of the 
internal iliac, passes downward and backward on the pelvic surface of the shaft of 
the ilium, along the ventral border of the iliac head of the obturator internus, ac- 
companied by the satellite vein and nerve, which lie ventral to the artery (Fig. 576). 
On reaching the obturator foramen it dips under the obturator internus and passes 
obliquely through the lateral part of the foramen. In this part of its course it 
gives off a vesical branch and twigs to the obturator internus and the hip-joint. 
It emerges from the obturator foramen behind the obturator externus, passes be- 
tween the quadratus femoris and the adductor, runs backward on the ventral face 
of the ischium, and, in the male, enters the crus penis, forming the arteria profunda 
penis. It anastomoses with the internal pudic, and usually with the external 
pudie by a branch (A. dorsalis penis caudalis) which runs forward on the dorsum 
penis. Collateral branches are detached to the obturator muscles, the adductors 
of the thigh, the semimembranosus, biceps femoris, and semitendinosus, and anas- 
tomoses are formed with the deep femoral and posterior femoral arteries. In the 
female the terminal part is small and enters the root of the clitoris. 
ARTERIES OF THE PELVIC LIMB 
The main arterial trunk of each pelvic limb descends to the proximal part of 
the posterior surface of the tibia, where it divides under cover of the popliteus 
muscle into the anterior and posterior tibial arteries. The different parts of the 
trunk receive names which correspond to the several regions through which it 
passes. In the abdomen it is termed the external iliac artery, in the proximal two- 
| thirds of the thigh it is called the femoral artery, and distal to this it is termed the 
_ popliteal artery. 
THE EXTERNAL ILIAC ARTERY (Figs. 575, 576) 
The external iliac artery (A. iliaca externa) arises from the aorta under the 
fifth lumbar vertebra, and usually just in front of the origin of the internal iliac. 
It descends at the side of the pelvic inlet along the tendon of the psoas minor, 
crosses the insertion of that muscle, and reaches the level of the anterior border of 
) the pubis, beyond which it is continued by the femoral artery. It is covered by the 
peritoneum and fascia, and is related behind to the corresponding vein. Its chief 
branches are as follows: 
1. The circumflex iliac artery (A. circumflexa ilium profunda) arises from the 
external iliac at its origin or from the aorta directly. It passes across the iliac 
fascia toward the tuber coxze, and divides into two branches at or near the lateral 
border of the psoas major. The artery lies between the fascia and the peritoneum 
and is accompanied by two veins. It furnishes small branches to the psoas muscles 
and the external iliac lymph glands. The anterior branch gives twigs to the iliacus 
and psoas muscles, and passes downward and forward in the flank on the trans- 
versus abdominis, along, or under cover of, the upper margin of the obliquus ab- 
dominis internus. It gives branches to these muscles, the obliquus abdominis 
externus, and the skin of the flank. The posterior branch perforates the abdominal 
wall close to the tuber cox, and runs downward on the medial face of the tensor 
43 
