82G SURGICAL ANATOMY OF INGUINAL HERNIA. 



of Poupart's ligament at the inner side of the Internal Oblique, being connected 

 with that muscle, and also occasionally with the Transversalis. It passes along 

 the outer side of the spermatic cord, descends with it through the external ring 

 upon the front and sides of the cord, and forms a series of loops, which differ 

 in thickness and length in different subjects. Those at the upper part of the 

 cord are exceedingly short, but they become in succession longer and longer, 

 the longest reaching down as low as the testicle, where a few ar.e inserted into 

 the tunica vaginalis. These loops are united together by areolar tissue, and 

 form a thin covering over the cord, the fascia cremasterica. The fibres ascend 

 along the inner side of the cord, and are inserted by a small pointed tendon, 

 into the crest of the os pubis and front of the sheath of the Eectus muscle. 



It will be observed, that the origin and insertion of the Cremaster is precisely 

 similar to that of the lower fibres of the Internal Oblique. This fact affords an 

 easy explanation of the manner in which the testicle and cord are invested by 

 this muscle. At an early period of foetal life, the testis is placed at the tower 

 and back part of the abdominal cavity, but, during its descent towards the 

 scrotum, which takes place before birth, it passes beneath the arched border of 

 the Internal Oblique. In its passage beneath this muscle some fibres are 

 derived from its lower part, which accompany the testicle and cord into the 

 scrotum. 



It occasionally happens that the loops of the Cremaster surround the cord, 

 some lying behind as well as in front. It is probable that, under these circum- 

 stances, the testis, in its descent, passed through instead of beneath the fibres of 

 the Internal Oblique. 



In the descent of an oblique inguinal hernia, which takes the same course as 

 the spermatic cord, the Cremaster muscle .forms one of its coverings. This 

 muscle becomes largely developed in cases of hydrocele and large old scrotal 

 hernias. No such muscle exists in the female, but an analogous structure is 

 developed in those cases where an oblique inguinal hernia descends beneath the 

 margin of the Internal Oblique. 



The Internal Oblique should be detached from Poupart's ligament, separated from the Trans- 

 versalis to the same extent as in the previous incisions, and reflected inwards on to the sheath of 

 the Rectus (Fig. 451). The circumflex iliac vessels, which lie between these two muscles, form 

 a valuable guide to their separation. 



The Transversalis muscle has been previously described (p. 362). Its lower 

 part is partly fleshy and partly tendinous in structure ; this portion arises from 

 the outer third of Poupart's ligament, and, arching downwards and inwards over 

 the cord, terminates in an aponeurosis, which is inserted into the linea alba, the 

 crest of the pubes, and the pectineal line to the extent of an inch, forming, 

 together with the Internal Oblique, the conjoined tendon. Between the lower 

 border of this muscle and Poupart's ligament, a space is left in which is seen 

 the fascia transversalis. 



The inguinal, or spermatic canal, contains the spermatic cord in the male, and 

 the round ligament in the female. It is an oblique canal, about an inch and a 

 half in length, directed downwards and inwards, and placed parallel with, and 

 a little above, Poupart's ligament. It communicates, above, with the cavity of 

 the abdomen, by means of the internal abdominal ring, which is the point where 

 the cord enters the spermatic canal ; and terminates, below, at the external ring. 

 It is bounded, in front, by the integument and superficial fascia, by the aponeu- 

 rosis of the External Oblique throughout its whole length, and by the Internal 

 Oblique for its outer third ; behind, by the conjoined tendon of the Internal 

 Oblique and Transversalis, the triangular ligament, transversalis fascia, and the 

 subperitoneal fat and peritoneum ; above, by the arched fibres of the Internal 

 Oblique and Transversalis; below, by the union of the fascia transversalis with 

 Poupart's ligament. That form of protrusion in which the intestine follows the 

 course of the spermatic cord along the spermatic canal, is called oblique inguinal 

 hernia. 



