276 



DISSECTION OF THE ABDOMEN. 



Subperi- 

 toneal tissue 

 in groin. 



Trace re- 

 mains of 

 peritoneum. 



Peritoneum 

 of the groin 

 is prolonged 

 on the cord : 



piece may 

 be imper- 

 vious, 



or saccu' 

 lated, 



or open. 



In female 

 may be 

 partly open. 



Spermatic 

 cord 



is oblique in 

 the abdomi- 

 nal wall, 



and vertical 

 beyond ; 



relations ; 



coverings. 



by cutting the transversalis fascia horizontally above the opening of 

 the ring, and then longitudinally over the cord. With the handle 

 of the scalpel the thin membrane may be reflected to each side, so 

 as to lay bare the subperitoneal fat. 



The subperitoneal fat forms a layer between the transversalis 

 fascia and the peritoneum. Its thickness varies much in different 

 bodies, but is greater at the lower than at the upper part of the 

 abdomen. This structure will be more specially noticed in the 

 examination of the wall of the abdomen from the inside. 



Dissection. After the subperitoneal fat has been seen, let it be 

 reflected to look for the remains of a piece of peritoneum which 

 extends along the cord in the form of a fibrous thread. 



The peritoneum, or the serous sac of the abdominal cavity, projects 

 forwards slightly opposite the internal abdominal ring. Connected 

 with it at that spot is a fibrous thread (the remains of a prolongation 

 to the testis in the foatus) which extends a variable distance along 

 the front of the cord. It is generally impervious, and can be followed 

 only a very short way ; but it may sometimes be traced as a fine 

 band to the tunica vaginalis of the testis. 



In some bodies the process may be partly open, being sacculated 

 at intervals ; or it may form occasionally a single large bag in front 

 of the cord. Lastly, as a rare state, it may remain unclosed as in 

 the foetus, so that a coil of intestine could descend in it from the 

 abdomen. 



In the female the fcetal tube of peritoneum sometimes remains 

 pervious for a short distance in front of the round ligament ; the 

 unobliterated portion being called the canal of Nuck. 



The SPERMATIC CORD (fig. 105, p. 286, and fig. 106, F, p. 287) extends 

 from the internal abdominal ring to the testis, and consists mainly 

 of the vessels and efferent duct of the gland, united together by 

 coverings from the structures by or through which they pass. 



In the wall of the abdomen the cord lies obliquely, since its aperture 

 of entrance amongst the muscles is not opposite its aperture of 

 exit from them ; but, escaped from the abdomen, it descends almost 

 vertically to its destination. In the oblique part of its course it is 

 contained in the passage named the inguinal canal ; it is placed at 

 first beneath the internal oblique, and rests against the transversalis 

 fascia; but beyond the lower border of the oblique muscle, it lies on 

 the upper surface of Poupart's ligament, with the aponeurosis of the 

 external oblique between it and the surface of the body, and the con- 

 joined tendon behind it. 



Its several coverings are derived from the strata in the wall of the 

 abdomen. Thus, from within outwards are 



(1) the subperitoneal fat, 



(2) the infundibuliform process of the transversalis fascia, 



(3) the cremaster muscle continuous with the internal oblique, 



(4) the intercolumnar or spermatic fascia from the external 

 oblique muscle, 



and, lastly, the superficial fascia and the skin. 



