842 



ILIAC ARTERIES. 



sing the external iliac with least danger to the 

 peritoneum, viz. on the outside of the deep 

 inguinal ring and close as possible to the crural 

 arch. The peritoneum of the anterior wall of 

 the fossa is weaker toward the middle line 

 than externally; it presents toward the abdo- 

 men two depressions or recesses denominated 

 by Velpeau " fossettes inguinales," internal 

 and external ; these depressions vary veiy much 

 in their depth, sometimes hardly perceptible, 

 at others of considerable depth and capacity, 

 more especially the external, which is much 

 the larger; they are produced by the projection 

 of the umbilical ligament from the interior of 

 the abdominal wall, and the reflection of the 

 peritoneum round the ligament, by means of 

 which a triangular fold, wide in proportion to 

 the degree to which the ligament projects, is 

 formed, the base of which is below, the apex 

 above toward the umbilicus, and in the free 

 edge of which the ligament is contained ; this 

 fold separates the depressions, one being 

 external to it, the other internal, between it 

 and the urachus ; the external one, the bottom 

 of which tends forward and inward, corresponds 

 to some point of the posterior wall of the in- 

 guinal canal, but its precise relation to it is 

 uncertain, because of the irregularity of the 

 position of the umbilical ligament ; at times 

 it is identical with another slight depression 

 situate on the outside of the epigastric vessels, 

 which marks the situation of the deep inguinal 

 ring, the ligament in such case being behind 

 these vessels ; at others it corresponds to the 

 wall of the canal, to the superficial inguinal or 

 the deep femoral rings, the ligament being in 

 these latter cases internal to the epigastric 

 vessels. 



The branches of the external iliac artery de- 

 serving of particular attention are usually two, 

 the anterior or circumflex iliac and the epigas- 

 tric arteries; throughout the superior part of its 

 course the artery gives only minute branches to 

 the peritoneum, the cellular tissue, the psoae 

 muscles, and the lymphatics; the other two, 

 which have been mentioned, are given off im- 

 mediately before the artery escapes from the 

 abdomen. They arise at a very short distance 

 above the crural arch, sometimes so high as 

 three-fourths of an inch from it, at others at it, 

 and sometimes again below the arch from the 

 femoral ; they proceed one from the outer and 

 the other from the inner side of the vessel, 

 sometimes opposite to each other, at others in- 

 differently one above the other; occasionally 

 they are given off from a trunk common to 

 both; they are nearly of equal size, but for the 

 most part the epigastric is larger than the cir- 

 cumflex. 



1. The anterior or circumflex iliac artery, 

 (arteria circumflexa iliaca or ilii ; Fr. artere 

 circonflexe iliaque, ou iliaque ou anterieure,) 

 arises from the outer side of the external iliac 

 on a level with or somewhat lower than the 

 epigastric; it runs outward and upward above 

 and parallel to the crural arch as far as 

 the superior anterior spinous process of the 

 ilium ; during this course it lies upon the fascia 

 iliaca superficial to the psoas and iliacus mus- 



cles and the anterior crural nerve, and it is 

 inclosed in a triangular canal, formed behind 

 by the fascia iliaca, below and above by la- 

 minae of the fascia transversalis, which divides 

 at its union with the former, in order to inclose 

 the artery. When the anterior abdominal wall 

 has been thrown down, and the peritoneum 

 with the fascia propria removed from the iliac 

 fossa, the course of the vessel may be traced by 

 a white line, which marks the union of the two 

 fasciae, extending from the middle of the crural 

 arch upward and outward within about three- 

 fourths of an inch of the spinous process of 

 the ilium; by the division of the fascia trans- 

 versalis along this line the artery will be ex- 

 posed. 



During its course toward the spinous process 

 the artery gives branches to the psoas and 

 iliacus, the transversalis and oblique muscles,, 

 and to the inguinal glands ; near the process it 

 gives upward a considerable branch, which 

 ascends in the anterior wall of the abdomen 

 between the internal oblique and transversalis 

 muscles, in front of the spinous process, serving 

 with its accompanying veins as a guide in dis- 

 section by which to distinguish between the- 

 two muscles; it divides into branches, which 

 are distributed to the muscles, as also to the 

 structures, which cover and line them, and 

 communicate with branches of the epigastric, 

 lumbar, and intercostal arteries. 



The circumflex artery pursues its course and 

 runs backward around and within the crest of 

 the ilium, internal to the transversalis muscle ; 

 during its course it gives branches inward to 

 the iliacus muscle which anastomose with si- 

 milar branches from the iliolumbar, and up- 

 ward to the lateral abdominal muscles, which 

 are partly distributed to them, partly turn over 

 the crest of the ilium and communicate with 

 the gluteal artery, and in part communicate 

 with the lumbar or intercostal arteries. Finally, 

 the artery, very much reduced in size, anasto- 

 moses freely with the termination of the ilio- 

 lumbar, which pursues a similar course in a 

 contrary direction around the interior of the 

 crest of the ilium. 



The circumflex artery has been found by 

 Monro to present an irregularity deserving of 

 notice ; he has seen a branch from it, nearly as 

 large as the epigastric, pass under the crural 

 arch, about two inches from the symphysis 

 pubis, and there divide into branches, which 

 were distributed upon the symphysis and the 

 fat and skin over the arch. 



2. The epigastric artery, (Fr. artere epigas- 

 trique, A. sus-pubienne) arises from the in- 

 ternal and rather anterior part of the iliac 

 artery, near to the crural arch ; the distance 

 of its origin from the arch, however, is liable 

 to variety ; for the most part it occurs about 

 half an inch above it, but it is frequently 

 nearer to it, or even at it, and occasionally it 

 is below it, arising from the femoral artery ; it is 

 given off, as has been stated, from that part 

 of the iliac, which is left uncovered by peri- 

 toneum, and its point of origin is posterior to, 

 sometimes above, sometimes on a level with, 

 and at others below the reflection of the mem- 



