342 ABDOMEN 



Reflection of Skin. Two incisions are required : (Fig. 127) (i) a 

 transverse incision along the line which separates the anal from the 

 urogenital triangle i.e. in front of the tuberosities of the ischia ; (2) an 

 incision at right angles to the first in the line of the median raphe. This 

 incision should begin well forwards on the scrotum and be continued back 

 a little beyond the point of the coccyx. The knife should be carried round 

 the anus so as to encircle it. 



The four triangular flaps which are marked out should now be reflected. 

 Some difficulty will be experienced in raising the skin. This is due to the 

 presence of a number of fasciculi of involuntary muscle which radiate 

 outwards from the anus. The term corrugator cutis ani is applied to this 

 muscle. The superficial fascia and the external sphincter muscle are now 

 exposed. 



FIG. 128. Outlet of Male Pelvis. 



Panniculus Adiposus (Superficial Fascia). The student 

 should examine the superficial fascia as it is spread over 

 the entire extent of the perineal space. It shows great 

 differences in character and texture in different positions. 

 At the side of the anus it is remarkable for the large 

 quantity of fat it holds in its meshes. This fat is soft 

 and lobulated, and passes upwards upon each side of the 

 anal canal in the form of a pliable and elastic pad. Over 

 the tuberosities of the ischia the superficial fascia under- 

 goes a striking alteration. Here it becomes tough and 

 stringy ; dense fibrous septa separate the lobules of fat from 

 each other and connect the skin with the subjacent bone. 



