200 ABDOMEN 



11. The spermatic cord. 



12. The inguinal canal. 



13. The extra- peritoneal fat. 



14. The parietal peritoneum. 



15- The obliterated umbilical artery. 

 1 6. The urachus. 



Dissection. Reflection of Skin. Incisions (i) Along the 

 middle line of the body from the xiphoid process of the sternum 

 to the symphysis pubis. The knife should be carried round the 

 navel so as to surround it with a circular incision. (2) From 

 the xiphoid process transversely round the thorax, as far back 

 as the knife can be carried. (3) From the symphysis pubis 

 laterally, along the line of the inguinal ligament, to the anterior 

 superior spine of the ilium, and then backwards along the crest 

 of the ilium (Fig. 91). 



The large flap of skin thus mapped out must be carefully 

 raised from the subjacent superficial fascia and turned laterally. 

 If the abdominal wall is flaccid, the dissection may be facili- 

 tated by inflating the abdomen. Make an incision through the 

 umbilicus, large enough to admit the nozzle of the bellows or an 

 injection-pipe fixed to a bicycle-pump, and, when the walls are 

 quite tense, secure the opening with twine, which should previously 

 be sewn through the skin round the lips of the incision. 



Panniculus Adiposus (Superficial Fascia). The superficial 

 fascia, laid bare by the reflection of the skin, presents the 

 same appearance, and possesses the same general characters, 

 as in other localities. Above, it is thin and weak, and is 

 directly continuous with the corresponding fascia over the 

 thorax; below, it becomes more strongly marked, and acquires 

 a greater density. Towards the lower part of the abdomen 

 the superficial fascia develops special characters ; it consists 

 of two layers a fatty superficial stratum called Camper's 

 fascia, and a deep membranous stratum termed Scarpc? s fascia* 



There is another point, however, in which the superficial 

 fascia differs somewhat from the same fascia in other parts of 

 the body. It is more elastic, the increased elasticity being 

 due to the augmentation of the elastic fibres in its deeper 

 membranous part. Over the lower part of the linea alba 

 the elastic tissue is collected in the form of a distinct band, 

 which descends, in front of the symphysis pubis, and becomes 

 connected with the suspensory ligament of the penis. A 

 reference to comparative anatomy gives interest to this fact. 

 The elastic band in the human subject is the rudimentary 

 representative of a continuous and distinct layer of yellow 

 elastic tissue (the abdominal tunic\ which is present in the 

 horse and other quadrupeds in which the weight of the 

 viscera is sustained chiefly by the abdominal wall. 



