1186 THE SURGICAL ANATOMY OF HERNIA. 



in the male and the round ligament in the female pass through this fascia ; the 

 point where they pass through is called the internal or deep abdominal ring. This 

 opening is not visible externally, owing to a prolongation of the transversalis fascia 

 on these structures, forming the infundibuliform process. 



The internal or deep abdominal ring is situated in the transversalis fascia, 

 midway between the anterior superior spine of the ilium and the symphysis pubis, 

 and about half an inch above Poupart's ligament. It is of an oval form, the 

 extremities of the oval directed upward and downward ; it varies in size in dif- 

 ferent subjects, and is much larger in the male than in the female. It is bounded 

 above and externally by the arched fibres of the Transversalis muscle, below and 

 internally by the deep epigastric vessels. It transmits the spermatic cord in the 

 male and the round ligament in the female. From its circumference a thin, 

 funnel-shaped membrane, the infundibuliform fascia, is continued round the cord 

 and testis, enclosing them in a distinct pouch. When the sac of an oblique 

 inguinal hernia passes through the internal or deep abdominal ring, the infundi- 

 buliform process of the transversalis fascia forms one of its coverings. 



The Subperitoneal Areolar Tissue. Between the fascia transversalis and the 

 peritoneum is a quantity of loose areolar tissue. In some subjects it is of con- 

 siderable thickness and loaded with adipose tissue. Opposite the internal ring it 

 is continued round the surface of the cord, forming a loose sheath for it. 



The deep epigastric artery arises from the external iliac artery a few lines above 

 Poupart's ligament. It at first descends to reach this ligament, and then ascends 

 obliquely along the inner margin of the internal or deep abdominal ring, lying 

 between the transversalis fascia and the peritoneum, and passing upward pierces 

 the transversalis fascia and enters the sheath of the Rectus muscle just below the 

 semilunar fold of Douglas. Consequently the deep epigastric artery bears a very 

 important relation to the internal abdominal ring as it passes obliquely upward 

 and inward from its origin from the external iliac. In this part of its course it 

 lies along the lower and inner margin of the internal ring and beneath the 

 commencement of the spermatic cord. As it winds round the internal abdominal 

 ring it is crossed by the vas deferens in the male and by the round ligament in the 

 female. 



The peritoneum, corresponding to the inner surface of the internal ring, presents 

 a well-marked depression, the depth of which varies in diiferent subjects. A thin 

 fibrous band is continued from it along the front of the cord for a variable distance, 

 and becomes ultimately lost. This is the remains of the pouch of peritoneum 

 which, in the foetus, accompanies the cord and testis into the scrotum, the 

 obliteration of which commences soon after birth. In some cases the fibrous band 

 can only be traced a short distance, but occasionally it may be followed, as a fine 

 cord, as far as the upper end of the tunica vaginalis. Sometimes the tube of 

 peritoneum is only closed at intervals and presents a sacculated appearance, or a 

 single pouch may extend along the whole length of the cord, which may be closed 

 above, or the pouch may be directly continuous with the peritoneum by an 

 opening at its upper part. 



In the female (in the foetus) the peritoneum is also prolonged in the form of a 

 tubular process for a short distance into the inguinal canal. This process is called 

 the canal of Nuck. It is generally obliterated in the adult, but sometimes it remains 

 pervious even in advanced life. It is analogous to the peritoneal pouch which 

 accompanies the descent of the testis. 



INGUINAL HERNIA. 



Inguinal hernia is that form of protrusion which makes its way through the 

 abdomen in the inguinal region. 



There are two principal varieties of inguinal hernia external or oblique, and 

 internal or direct. 



External or oblique inguinal hernia, the more frequent of the two, takes the 



