292 



DISSECTION OF THE ABDOMEN. 



other 



hernia are 



femoral, 



obturator, 



sciatic. 



Dissection 

 abdomen 



Cords on 

 nai 



Three 



external, 



internal, 



and middle. 



Situation of 



Dissection 



hernia. It should be remembered that the narrowed neck is at the 

 upper end and not in the centre of the swelling. 



OTHER FORMS OF HERNIA. At each of the other apertures in the 

 parietes of the abdomen, a piece of intestine may be protruded, so 

 as to form a hernia. For instance, there may be femoral hernia below 

 Poupart's ligament, with the femoral vessels ; obturator hernia 

 through the thyroid foramen, with the artery of the same name ; and 

 sciatic hernia through the sciatic notch. 



The femoral hernia, as the most important, will be noticed 

 presently ; but the student will refer to special treatises for detailed 

 information respecting the heruim. 



Dissection, The abdomen is now to be opened to see the cords 

 an( ^ depressions on the posterior surface of the wall. A transverse 

 cut may be made through the umbilicus across the front of the 

 abdomen ; and on holding up the lower half of the wall, three 

 prominent fibrous cords, the urachus and the obliterated hypogastric 

 arteries, will be seen ascending to the umbilicus from the pelvis. 



Cords on the abdominal icall. In the middle line is the urachus, 

 which reaches from the summit of the bladder to the umbilicus ; on 

 each side is the obliterated hypogastric artery, extending from the 

 side of the pelvis to the umbilicus ; and a little external to the last, 

 near Poupart's ligament, is a less marked prominence of the perito- 

 neum caused by the deep epigastric artery. 



Fossce. With this disposition of the cords, three hollows (inguinal 

 fossa) are seen near Poupart's ligament, one internal to the obliterated 

 hypogastric artery, another outside the deep epigastric artery, and 

 the third between the two. The external fossa corresponds by its 

 lower and inner part to the internal abdominal ring, opposite which 

 there is often a slight depression or dimple of the peritoneum, and is 

 the place where an external inguinal hernia begins to protrude. The 

 internal fossa is between the obliterated hypogastric artery and the 

 urachus ; its outer part is opposite the external abdominal ring, and 

 is the seat of the commoner (inferior) variety of internal hernia. 

 The middle fossa is the smallest, and is placed behind the inguinal 

 canal ; in it the superior variety of internal hernia leaves the abdo- 

 minal cavity. 



In some bodies the obliterated hypogastric artery is close to, or 

 behind, the epigastric artery ; and in that case the middle fossa will 

 be wanting. 



FEMORAL HERNIA. In this hernia the intestine leaves the 

 abdomen below Poupart's ligament, and descends in the membranous 

 sheath around the femoral vessels. Only so much of the structures 

 will be described here as can be now seen ; the rest have been 

 noticed fully in the dissection of the thigh (pp. 143 et seq). 



Dissection. The dissection for femoral hernia is to be made on 



Divide will 

 ' 



^ ower portion of the abdominal wall is to be divided from the 

 umbilicus to the pubis, the cut being made on the left side of the 

 urachus, and care being taken not to injure the bladder, which may 



