944 THE VASCULAR SYSTEM. 



inguinal ligament (Poupart's), midway between the anterior superior spine of the 

 ilium and the symphysis pubis, where it becomes the femoral artery. Its length 

 is about 87 to 100 mm. (three and a half to four inches), and in the adult it is 

 usually somewhat larger than the hypogastric artery. 



It runs downwards, forwards, and laterally, along the superior aperture ol 

 the pelvis minor, resting upon the fascia iliaca, which separates it, above, frona 

 the medial border, and, below, from the anterior surface of the psoas inajoi 

 muscle ; and it is enclosed, with its accompanying vein, in a thin fascial sheath. 



Relations. Anterior. It is covered in front by peritoneum, which separates it 01 

 the left side from the iliac colon, and coils of small intestine, and on the right side fron 

 the terminal portion of the ileum, and sometimes from the vermiform process. Thi 

 ureter, descending behind the peritoneum, sometimes crosses the front of the arter 

 near its origin, and in the female the ovarian vessels cross the upper part of the artery 

 Near its lower end the artery is crossed anteriorly by the external spermatic branch o 

 the geni to-femoral nerve and by the deep circumflex iliac vein. In the male this part o 

 the artery is crossed also by the ductus deferens, and in the female by the round ligamen 

 of the uterus. Several iliac lymph glands lie in front and at the sides of the externs 

 iliac artery, and almost invariably one of these is directly anterior to its termination. 



Posterior. The fascia iliaca and psoas major muscle lie behind the artery. Near it 

 upper end the obturator nerve and the external iliac vein are posterior to the vessel. 



Lateral. On its lateral side is the genito-femoral nerve. Medial. To the medk 

 side of its lower part is the external iliac vein. 



Branches. In addition to small branches to the psoas major muscle and t 

 the lymph glands, two named branches of considerable size spring from the extern? 

 iliac artery, viz., the inferior epigastric and the deep circumflex iliac. 



(1) Arteria Epigastrica Inferior. The inferior epigastric artery (Figs. 7*74 an 

 777) arises, immediately above the inguinal ligament, from the front of the extern; 

 iliac. It lies in the extra-peritoneal fat, it curves forwards from its origin, tun^ 

 round the lower border of the peritoneal sac, and runs upwards and medially, alon 

 the medial side of the abdominal inguinal ring and along the lateral border of tl; 

 medial inguinal fossa ; it then pierces the transversalis fascia, passes over the sem 

 circular fold (Douglas) and enters the sheath of the rectus abdominis muscle. For I 

 short distance it ascends posterior to the rectus, but it soon penetrates the substan* 

 of the muscle, and breaks up into branches which anastomose with terminal offse 

 of the superior epigastric branch of the internal mammary artery and with tl 

 lower intercostal arteries. At the abdominal inguinal ring, in the male, the ducti 

 deferens, the testicular vessels, and the external spermatic branch of the genit 

 femoral nerve hook round the front and lateral side of the artery, the duct 

 deferens turning medially behind it; whilst in the female the round ligame: 

 of the uterus and the external spermatic branch of the genito-femoral ner . 

 occupy the corresponding positions. 



Branches. (a) Muscular branches supply the rectus, the pyramidalis, the trai 

 versus, and the oblique muscles of the abdominal wall, and anastomose with branches 

 the deep circumflex iliac, the lumbar, and the lower intercostal arteries, (b) Cutaneo 

 branches, which pass from the front of the inferior epigastric, pierce the rectus abdomii 

 and the anterior part of its sheath, and terminate in the subcutaneous tissues of t 

 anterior abdominal wall, where they anastomose with corresponding branches of t 

 opposite side and with branches of the superficial epigastric artery, (c) The exten 

 spermatic in the male (artery of the round ligament of the uterus in the female) 

 small. It descends through the inguinal canal and anastomoses with the exteri 

 pudendal and the scrotal branches of the perineal artery, and in the male with 1 ' 

 internal spermatic artery also. In the male it accompanies the spermatic funicul , 

 supplying its coverings, including the cremaster. In the female it runs with the rot I 

 ligament, (d) The pubic branch descends, either on the lateral or the medial side of 3 

 femoral ring, to anastomose with the pubic branch of the obturator artery ; it anastomc 3 

 also with its fellow of the opposite side. Sometimes, when the obturator branch of 

 hypogastric artery is absent, the pubic branch of the inferior epigastric artery enlar 3 

 and becomes the obturator artery, which descends to the obturator foramen either 1 



