752 



HERNIA. 



through this ring, it has the epigastric artery to 

 its internal or pubic side, and generally the 

 vessels of the cord behind it; but a variety 

 sometimes occurs, for the hernia may protrude 

 exactly at the spot where the spermatic artery 

 and vas deferens meet eacli other at an angle, 

 and separate these vessels from each other, 

 leaving the artery rather to the outside and in 

 front, tlie vas deferens still occupying its usual 

 situation behind. After the hernia has passed 

 the fascia transversalis, it is still behind tlie 

 fibres of the internal oblique and transversa'.is 

 muscles, and has to pass a few lines (the dis- 

 tance varying in different subjects) before it 

 reaches the posterior surface of tlie tendon of 

 the external oblique. On prosecuting this dis- 

 section further by detaching the fascia trans- 

 versalis from the transversalis muscle in a di- 

 rection downwards and outwards, the intestine 

 will be found to have entered a canal of an inch 

 and a quarter to an inch and a half in length, 

 its direction being obliquely downwards and 

 inwards to the external ring. This is termed 

 the inguinal canal, and is thus formed. Pou- 

 part's ligament, whether it be considered as a 

 portion of the tendon of the external oblique or 

 not, is powerfully strong and thick : to it the 

 fascia transversalis is firmly adherent behind, 

 and the thinner and more expanded fibres of 

 the tendon of the external oblique before. 

 Between these, then, a sheath is formed in 

 which the hernia is lodged, having in front the 

 tendon of the external oblique, and also covered 

 by the cremaster muscle, particularly that part 

 of it which has its origin from Poupart's liga- 

 ment. Behind it is the fascia transversalis, 

 and more internally or nearer the pubis the 

 conjoined tendon oif the internal oblique and 

 transversalis, and below is Poupart's ligament. 

 Above, it is crossed obliquely by the inferior 

 margin of tlie internal oblique and transversalis. 

 These muscles have a Heshy origin from the ex- 

 ternal third of Poupart's ligament, from which 

 they pass in an arched form to be inserted by 

 a common tendon into the crest of the pubis. 

 Under this arch the viscus slips and thus places 

 itself anterior to the conjoined tendon before 

 passing through the external ring and becoming 

 a scrotal hernia. 



Anatomists have not agreed in their descrip- 

 tions of the internal oblique muscle, although 

 a correct and accurate knowledge of the situa- 

 tion of it and of the transversalis in the neigh- 

 bourhood of the rings is indispensable to the 

 right understanding of hernia. According to Sir 

 A. Cooper* and Lawrence, t the upper part 

 only of the internal ring is shut up by these 

 muscles, leaving the lower unprotected, and con- 

 sequently, according to this view of the subject, 

 a hernia on entering the inguinal canal should 

 have them above it. CloquetJ stales that the 

 inferior border of the transversalis passes on a 

 level with the superior, opening internally, but 

 the edge of the internal oblique is lower down, 



covers the spermatic cord in tlie inguinal canal, 

 and passes over it to be inserted into the pubis 

 at the point where it csfiipcx J'nmi the iiiju'ior 

 opening f the canal, that is, the external ring. 

 Scarpa* gives a different description still, where 

 he says, " towards the side at about eight lines 

 distance from the apex of the ring, the lower 

 muscular fibres of the internal oblique muscle 

 separate from each other to allow the sper- 

 matic cord to pass between them ;" and 

 Guthrief considers the occasional passage of a 

 hernia through the fibres of this muscle, and its 

 compression by them, lobe nounfrequent cause 

 of strangulation. It is not easy to reconcile 

 these conflicting authorities, which in them- 

 selves demonstrate the fact that the inferior 

 border of this muscle exhibits some varieties in 

 its relation to the inguinal canal and internal 

 ring according to the extent of its origin from 

 Poupart's ligament. When a hernia is present, 

 I have always seen it arched over the neck of 

 the sac, and although I would by no means 

 assert that a rupture never takes its course 

 between these muscular fibres, yet I have not 

 met with an instance, and as I have observed 

 elsewhere, I imagine such an occurrence would 

 create a deviation from the usual relative 

 anatomy of the cremaster muscle with respect 

 to the hernial sac. See ABDOMEN. 



The inguinal canal terminates in front at the 

 external ring, which is formed by a separation 

 of the fibres of the external oblique muscle as 

 it passes inwards and downwards to be inserted 

 into the pubis. Almost immediately after the 

 muscle has become tendinous, a disposition to 

 this separation is observable, and a kind of split 

 is formed in the tendon, the edges of which 

 are, however, pretty firmly held in their re- 

 lative positions by fibres passing closely and 

 irregularly across from one to the other. These 

 fibres have been called the intercolumnar fascia. 

 Besides these there is a very remarkable ar- 

 rangement of tendinous fibres seeming to arise 

 from Poupart's ligament, and thence radiating 

 in an arched form (the convexity of the arck 

 looking towards the pubis) to form a strong in- 

 terlacement with the fibres of the external 

 oblique. J Independent of these adventitious 

 bands the tendon itself, as it approaches the crural 

 arch and the pubis, seems to become thicker 

 and stronger ; and (as has been remarked by 

 Scarpa) in the dead body after the integuments 

 are removed and the parts left for some time 

 exposed, the lower portion of the aponeuiosis 

 appears opaque and dense, while the part above 

 the umbilicus preserves its transparency, and 

 allows the fleshy fibres of the subjacent muscle 

 to be seen through it. The separation above 

 alluded to being effected, the tendon is divided 

 into two portions, termed the pillars of the 

 ring : the anterior or internal is broader and 

 flatter, and runs to be inserted into the pubis of 

 the opposite side, and the ligamentous sub- 

 stance that covers the front of this bone. The 



Page 6. 



t Lawrence on Ruptures, p. 162. 

 i Anatomy of Hernia, by Jules Cloquct, trans- 

 lated by M'Whinaic, p. 6. 



* Page 25. 



t Anatomy of Hernia. 



t Sometimes termed Camper's fascia, from its 

 being so admirably delineated iu the " Icones." 



