4i8 



ABDOMEN 



have a similar course to the arteries, and end in fine twigs 

 to the papillae of the glans. 



TRIGONUM LUMBALE AND LUMBAR FASCIA. 



On the sixth day after the body was placed on its back it will be turned 

 upon its face, with blocks supporting the thorax and pelvis, and in this 

 position it will remain for five days. At the end of the first or the 

 beginning of the second day of this period, when the dissector of the upper 

 extremity has cleaned the latissimus dorsi, the dissector of the abdomen 

 must take the opportunity of examining the posterior border of the external 

 oblique. As the posterior border of the muscle passes from the last rib to 



Sacrospinalis 



Quadratus 

 lumborum 



Psoas 

 magnus 



Serratus 

 post. inf. 



Latissimus 

 dorsi 



Transversus 

 abdominis 



Internal 



oblique 



External 



oblique 



Fascia 

 transversalis 



FIG. 158. Lumbar fascia and sheath of Rectus abdominis. 

 The dotted line represents the Peritoneum. 



the lateral lip of the iliac crest it is quite free and, in many cases, there is 

 a small triangular interval between it and the lower part of the lateral 

 border of the latissimus dorsi in which the fibres of the more deeply situated 

 internal oblique can be seen. This is the trigonum himbale Petiti. It is a 

 comparatively weak region of the abdominal wall, and in some rare cases 

 hernia of the abdominal contents occurs through it. Not uncommonly, 

 however, the lateral border of the latissimus dorsi overlaps the posterior 

 border of the external oblique, and in these cases the trigonum lumbale does 

 not exist. 



On the third day, after the dissector of the upper extremity has reflected 

 the muscles which connect the upper extremity with the trunk on the 

 posterior aspect, the dissector of the abdomen, in association with the 

 dissector of the head and neck, should examine the lumbar fascia and the 

 lumbar origins of the internal oblique and the transversus abdominis 

 muscles. 



The lumbar fascia is a portion of the lumbo-dorsal fascia which binds 



