INGUINAL HERNIA 



1395 



layer, it carries with it a coating of tissue from that layer; e. g., the inferior cava passing through 

 its foramen in the diaphragm, and the membranous urethra through the m-o-genital diaphragm. 



Effect of position of the thigh on the ring. — As the lower crus is blended with Poupart's 

 ligament, and as the fascia lata is connected with this, movements of the thigh will affect the 

 ring much, making it tighter or looser. Thus extension and abduction of the thigh stretch 

 the criu-a and close the ring. In flexion and adduction of the thigh the crm-a are relaxed; and 

 this is the position in which reduction of a hernia is attempted. In flexion and abduction of 

 the thigh, the ring is open; and this is the position in which a patient should sit, with thighs 

 widely apart, to try on a truss, and cough or strain downward, as in rowing. If the hernia is 

 now kept up, the truss is satisfactory. 



Helping to protect this most important spot, and preventing its being more than a potential 

 ring, are not only the two crura and the intercrural fibres, but also a structure which has been 

 called a third or posterior pillar, namety, the reflected inguinal ligament. This has its base 

 above at the lower part of the linea alba, where it joins its fellow and the aponeurosis of the 

 external oblique, and its apex downward and lateraUj', where, having passed behind the medial 

 crus it blends with the lacunar (Gimbernat's) ligament. Again, the falx inguinalis (the con- 



FiG. 1119 — The Parts concerned in Inguinal Hernia. 

 (From a dissection in the Hunterian Museum.) 

 External oblique, cut and turned back Internal oblique External oblique 



Falx inguinalis 



Poupart's (inguinal) ligament 



Reflected inguinal ligament 



Transversus 



Fascia trans- 

 versalis 



Peritoneum 



Common fem- 

 oral vessels 



joined tendon of the internal oblique and transversahs), curving medially and downward to 

 be attached to the ilio-pectineal line and spine, is a most powerful protection, behind, to what 

 is otherwise a weak spot and a potential ring. 



Inguinal canal. — This is not a canal in the usual sense, but a chink or flat- 

 sided passage in the thickness of the abdominal wall. The descriptions of the 

 canal usually given apply rather to the diseased than to the healthy state. It 

 was a canal once, and for a time only, i. e., in the later months of foetal life (p. 1387). 

 It remains weak for a long time after, but only a vestige of it remains in the well- 

 made adult. 



Length.— In very early life there is no canal; one ring lies directly behind the 

 other, so as to facilitate the easy passage of the testis. In the adult it measures 

 about 37 mm. (1| in.) in length, this lengthening being brought about by the 

 growth and separation of the alse of the pelvis. This increased obliquity gives 

 additional safety. On the other hand, a large hernia has not only opened widely 

 the canal and rings, but it has pulled them close together, and one behind the other 

 thus not only rendering repair much more difficult, but also the path to the 



