ILIAC ARTERIES. 



841 



between it and the fascia transversalis ; it ap- 

 proaches very near to the inner margin of the 

 deep ring, and at its insertion into the pectineal 

 line it meets and is identified with Gimbernat's 

 ligament; it is closely adherent to the surface of 

 the fascia transversalis, and hence that fascia 

 presents an appearance of thickness and strength 

 upon the inside of the deep ring, which it does 

 not really possess. From the inferior margin 

 of the internal oblique and from the superior 

 side of the crural arch the cremaster muscle 

 descends upon the anterior and external part of 

 the spermatic process, forming one of the 

 coverings of the process within the inguinal 

 canal, of course concealing it after the division 

 of the aponeurosis of the external oblique, and 

 requiring to be detached from the arch along 

 with the~lower fibres of the internal oblique in 

 order that the process may be fairly exposed. 



The deep structures of the anterior wall of 

 the iliac fossa are also three, viz., the fascia 

 transversalis, the fascia propria, and the peri- 

 toneum. 



1. The fascia transversalis is most remark- 

 able in the iliac region, but it is not con- 

 fined to it, being to be traced upward to 

 the surface of the diaphragm, and backward 

 round the interior of the lateral walls of the abdo- 

 men. In the iliac region this fascia is inferiorly 

 first identified with the fascia iliaca from a short 

 distance behind the anterior superior spinous 

 process of the ilium to the outer side of the 

 external iliac artery, or about the middle of the 

 crural arch ; the line of its connection with the 

 fascia iliaca runs downward, forward, and in- 

 ward, at a short distance within the crest of 

 the ilium and the crural arch, approaching the 

 latter, however, as it descends, until at the 

 outside of the artery it touches it ; it is sepa- 

 rated along this line into two laminae which 

 enclose the circumflex iliac artery between 

 them ; there is, therefore, an interval between 

 the arch and the line of connection of the two 

 fasciae in which the fascia iliaca intervenes, and 

 to the surface of this part of the fascia it is 

 that the internal oblique and transverse muscles 

 are attached. In the second place the fascia 

 transversalis descends into the thigh beneath 

 the crural arch, between it and the iliac vessels, 

 and forming the front of their sheath; and, 

 thirdly, it is attached upon the inside of the 

 vessels, along the pectineal line of the pubis 

 posterior to the conjoined tendon of the internal 

 oblique and transverse muscles, between it and 

 the peritoneum, and separated by it from the 

 spermatic process, which is in front of both. 



Internally the fascia transversalis is con- 

 nected to the edge of the tendon of the rectus. 



Midway between the superior anterior spi- 

 nous process of the ilium and the spinous pro- 

 cess of the pubes, and at from half to three- 

 fourths of an inch above the crural arch, the 

 spermatic process escapes from the abdomen, 

 descending within a cylindrical prolongation of 

 the fascia by which the process is enclosed, and 

 which thus forms a sheath for the process. By 

 detaching this prolongation from the fascia 

 around the process, a circular aperture is 

 formed in the fascia, which is the deep in- 



guinal ring, the situation of which has been 

 just defined. On the inside of this opening- 

 are situate the epigastric vessels, the artery f 

 and vein or veins, the artery in the former case 

 being next the ring, in the latter at times the 

 outer of the two veins. 



2. The fascia propria is a cellular stratum in- 

 terposed between the peritoneum and the struc- 

 tures of the abdominal walls which it lines ; it 

 varies in thickness and condition at different 

 parts and in different subjects ; at times it con- 

 tains adeps, at others it is purely cellular, or 

 forms a condensed expansion ; in the iliac 

 region it is thicker upon its posterior than its 

 anterior wall ; on the latter it increases in 

 thickness as it descends towards the crural 

 arch, being so thin towards the umbilicus that 

 the peritoneum adheres very closely to the ten- 

 dinous expansion of the muscles ; at the deep 

 inguinal ring it is more dense, and the perito- 

 neum, the fascia transversalis, and it, are more 

 intimately connected than at either side; ex- 

 ternal to the ring, between it and the spinous 

 process of the ilium, it is so free that the pe- 

 ritoneum may be separated without difficulty 

 from the interior of the fascia transversalis, 

 and along the crural arch it forms, from the 

 external iliac artery outward, a soft mass, 

 sometimes thick, occupying the interval left 

 between the peritoneum and the fascia trans- 

 versalis, at the reflection of the former from 

 the iliac fossa to the anterior wall : upon this 

 wall it encloses the epigastric vessels, the um- 

 bilical ligament, and the spermatic vessels, and 

 not only does it extend universally over the in- 

 terior of the abdominal walls but it is prolonged 

 through their several apertures upon the parts 

 which pass through them, as in the case of the 

 spermatic vessels. 



From the anterior wall of this region it passes 

 to the posterior, where it lines the iliac fossa, 

 and connects the peritoneum or the viscera to 

 the iliac fascia ; at the outer part of the fossa 

 it is remarkably free, soft, and easily lacerated, 

 so that the peritoneum can be detached, pro- 

 bably with greater facility at this than at any 

 other situation; at its inner part it is even more 

 abundant, thicker the nearer to the crural arch, 

 forming the investment by which the iliac ves- 

 sels are inclosed, and descending thence into 

 the pelvis. 



Lastly, the peritoneum of the anterior wall 

 is continuous inferiorly with that of the iliac 

 fossa, being reflected from the one to the other 

 at the distance of five or six lines above the 

 crural arch a fact deserving of much attention, 

 since it permits the external iliac artery to be 

 secured without disturbing the membrane. In 

 its reflection from one wall of the region to 

 the other it leaves immediately above the crural 

 arch, between itself, the fascia transversalis, 

 and the fascia iliaca, a triangular interval of 

 some lines, occupied by the fascia propria, 

 and at times at least by one or more lymphatic 

 glands ; this space is widest at the iliac artery 

 and diminishes as it extends outward ; this fact 

 also deserves attention, inasmuch as it points 

 out where the fascia transversalis may be di- 

 vided, if necessary, in the operation of expo- 



