1134 



SURGICAL AND TOPOGRAPHICAL ANATOMY 



opposite the femoral vessels it also joins the fascia iliaca, and forms with it a 

 funnel-shaped sheath; {d) internal to the femoral vessels the fascia transversalis is 

 attached to the ilio-pectineal line, behind the conjoined tendon, with which it 

 blends. 



INTERNAL RING. — It has already been said that the term ' ring' is here mis- 

 applied except in an artificial sense, as when an opening is made by a scalpel; or 

 in a i)athological one, as when a hernia is making its way by opening nj) the parts. 

 The terms ' internal ' and ' external ' are also misap]jlied as far a-s their usual a})})li- 

 cation to the middle line of the body is concerned. The terms apply to depth only. 

 The ' internal ring ' is not a ring in the least, but merely a funnel-shaped expansion 

 of the transversalis fascia, which the cord carries on with it as it escapes from the 

 abdomen. This expansion may be Aveakened, but it is never an opening save when 

 made so artificially. 



Site. — ^Midway between the anterior superior s^iine and spine of pubes. Shape : 



Fig. 702. 



-Dissection of the Lower Part of the Abdominal Wall from within, 

 THE Peritoneum having been removed. (Wood.) 



Fascia trans- 

 versalis 



Epigastric artery- 



Internal abdom-_ 

 inal ring 



VAS DEFERENS >w\\ 



Spermatic \ 



vessels ^ 



Border of the 

 posterior part 

 of the sheath 

 of the rectus 

 (fold of Doug- 

 las) 



Posterior surface 

 of rectus 



Conjoined tendon 

 in the triangle 

 of Hesselbach 



Obhlrralfd h>/j,n- 

 gasti ic arterii 



Lymphatics in 

 crural rings 



EilTnal iliac artery 



oval, with the long diameter upwards. Dimensions : one inch (25 mm.) by half 

 an inch. Both these are artificial. Boundaries : centre of Poupart's ligament, 

 about half an inch below. Internally, the deep epigastric artery (fig. 702); and 

 thus the inner side seems to be better defined. But the outer side is really the better 

 defined, as here the transversalis fascia is descending to Poupart's ligament, to form 

 the deep ' crural ' arch, and to help to close in the great gap or notch betweini Pou- 

 part's ligament and tlie innominate bone. Owing to the artery lying to the inner 

 side, tlie incision, in cutting to relieve the deep constriction of an inguinal hernia, 

 should always be made directly upwards, so as to avoid the above vessel. 

 Coverings. — There are two chief forms of inguinal hernia: — 



A. The common form : external, or oblique. — External, Ixx'ause it appears 

 (at the internal rhig) external to the deep epigastric artery. Oblique, because it 

 traverses the whole of the inguinal canal, entering it at its inlet and leaving it at 

 its outlet. 



B. Rarer form : internal, or direct. — Internal, because it appears internal 



