12 



ABDOMEN. 



The fascia transversalis is best seen by re- 

 moving the muscles which lie anterior to it : it 

 is then distinctly observed to extend from the 

 outer margin of the rectus muscle internally 

 over the posterior surface of the anterior wall of 

 the abdomen, and gradually to assume the 

 character of a thin but condensed cellular la- 

 mella over the abdominal surface of the lateral 

 wall : it may, however, be traced internally as 

 far as the linea alba behind the rectus muscle, 

 but here it is extremely thin, and has totally 

 lost the fibrous character. Inferiorly this fascia 

 adheres to Gimbernat's ligament and to the 

 reflected margin of Poupart's, from which it is 

 said, by some French anatomists, to originate. 

 Along the line of Poupart's ligament and ex- 

 ternal to it along the crista ilii, this fascia is 

 united with the fascia iliaca, the union be- 

 ing indicated by a white opaque line formed 

 by a thickening of the membrane, taking the 

 course of Poupart's ligament and the crista ilii, 

 except where it is interrupted for the passage of 

 vessels or other parts. Superiorly, the fascia 

 transversalis also degenerates into a cellular 

 lamella, which passes on the transversalis 

 muscle to the diaphragm. It is for a short 

 distance above Poupart's ligament that this 

 fascia demands most attention ; here it forms the 

 posterior wall of the inguinal canal, and at a 

 point a little external and superior to the middle 

 of Poupart's ligament it presents an opening or 

 separation of its fibres, through which the sper- 

 matic vessels and vas deferens united by lax 

 cellular tissue pass into the inguinal canal, 

 carrying around them a funnel-shaped mem- 

 brane which seems to be a prolongation from 

 or continuation of the margins of this opening, 

 but which is in texture merely a condensed cel- 

 lular layer. This prolonged membrane is the 

 first covering which the spermatic cord receives 

 upon its formation, which takes place as its 

 several constituent parts meet at the opening or 

 slit in the fascia transversalis ; it immediately 

 invests the cellular tissue connecting these parts, 

 which is the tunica vaginalis of the cord ; as 

 it proceeds, the cremaster muscle adheres to it 

 from the external oblique and transversalis 

 muscles, and this again receives at its exit 

 through the external abdominal ring another 

 cellular expansion, to which we have already 

 alluded. 



The opening or slit in the fascia transversalis 

 which we have just described is denominated 

 by anatomists the internal abdominal ring, 

 although, if we speak with reference to the mid- 

 dle line, it is external to the opening in the 

 tendon of the obliquus externus, which is called 

 the external ring. It would certainly be more 

 consistent with the ordinary use of these ad- 

 jectives in anatomy to reverse their application, 

 or if the term anterior were applied to the ex- 

 ternal ring, and posterior to the internal, every 

 purpose would be answered. 



The direction of the internal abdominal ring 

 is vertical and inclined very slightly outwards. 

 When the fibrous character of the fascia trans- 

 versalis is obvious, we can generally observe 

 two very distinct portions of it, one on each 

 side of the ring. The fibres of the external 



portion pass upwards and inwards ; those of 

 the internal portion, which are generally stronger 

 and more developed than in the external, pass 

 upwards and outwards so as to decussate with 

 the external fibres at the upper extremity of the 

 ring. The outer margin of this internal portion 

 often presents towards the ring a lunated ap- 

 pearance, over which the vas deferens turns at a 

 sharp angle ; it can be best seen by examining 

 the parts from behind after the peritoneum has 

 been removed.* The fascia transversalis is 

 continued upwards along the posterior and 

 lateral surface of the abdominal muscles and 

 over the diaphragm under the form of a fine 

 lamina of very condensed cellular membrane, 

 which adheres pretty closely to the muscles, 

 but especially to the diaphragm, where it 

 seems to be incorporated with the proper cel- 

 lular covering of that muscle. We refer to 

 the article GROIN, REGION OF THE, for further 

 particulars respecting the fascia transversalis. 



In the iliac fossa we find a very distinct 

 fibrous expansion covering the whole abdo- 

 minal surface of the iliacus internus muscle. 

 This is tine fascia iliaca. It is seen by raising 

 the peritoneum and the subperitoneal cellular 

 tissue from the fossa. Inferiorly this fascia is 

 connected with the fascia transversalis along 

 the line of Poupart's ligament, except where 

 that connexion is interrupted by the passage of 

 the vessels under the ligament. That space 

 comprises the interval between the inner margin 

 of the tendon of the Psoas and Gimbernat's 

 ligament; and here the fascia lies close to the 

 horizontal ramus of the pubis, and passes be- 

 hind the vessels into the upper part of the thigh, 

 where it adheres to the linea ilio-pectinea, 

 and seems to become continuous with the 

 fascia lata. Externally the fascia iliaca is con- 

 tinuous with the fascia transversalis along the 

 crista ilii, where an opaque line indicates the 

 union, and just internal to which it splits to 

 ensheath the circumflexa ilii artery. On the 

 inner side of the iliac fossa this fascia unites 

 with the pelvic fascia along the brim of the 

 pelvis, this union being likewise indicated by 

 an opaque line similar to that already noticed 

 along the crista ilii. To arrive at this point the 

 fascia, in proceeding from without inwards, 

 passes over the iliacus internus, then over the 

 psoas magnus and parvus, upon which it is 

 thinner than elsewhere ; it then passes behind 

 the iliac artery and vein, and arrives at the 

 pelvic margin. Posteriorly this fascia is con- 

 tinuous with a thin and less fibrous expansion 

 which covers the psoas and quadratus lumborum 

 muscles, adheres to the ligamentum arcuaturn, 

 and is identified superiorly with the cellular 

 expansion on the diaphragm, and externally 

 with the fascia transversalis. 



It has already been stated that the iliac fascia 

 passes behind the iliac vessels. These vessels 

 have also anterior to them a fibrous or cellulo- 

 fibrous expansion, which is connected on the 

 inner and outer side to the fascia iliaca. Some 



* This lunated margin is very well delineated by 

 Cloquet in the third figure of the first plate annexed 

 to his work on Hernia, now translated by Mr. A.M. 

 M'YVhinuic. 



