THE ABDOMEN 



765 



witlriii its sheath, and, passing behind Poupart's ligament and the femoral 

 vessels encased in the crural sheath, it usually points over the saphenous 

 opening on a level with the small trochanter, where it may simulate a femoral 

 hernia. 



Lumbar Aponeurosis. — This is situated between the last rib and 

 the iliac crest, and is to be regarded as the posterior aponeurosis of 

 the transversalis abdominis muscle. When followed backwards it 

 divides into three laminae, anterior, middle, and posterior. The 

 anterior lamina, which is thin, covers the quadratus limiborum, and 

 is attached internally to the fronts of the transverse processes of 

 the lumbar vertebrae near their tips. In this situation it is inter- 

 posed between the quadratus Imnborvun and psoas magnus, and 

 receives the iliac fascia which forms the psoas sheath. At the outer 



Erector Spinae 



Lumbar 

 Spine 



Transverse Process 



Posterior Lamina of Lumbar Aponeurosis 



Middle Lamina of Lumbar Aponeurosis 

 Quadratus Lumborum 



Anterior Lamina of Lumbar 

 Aponeurosk 

 Latissimus Dorsi 



Body of 3rd Psoas Magnus, covered 

 Lumbar Vertebra by Psoas Fascia 



Obliquus Ext. Abd. 

 Obliquus Int. Abdominis 

 Transversalis Abdominis 



Fig. 328. — Diagram of the Lumbar Aponeurosis. 



border of the quadratus lumborum it joins the middle lamina, and 

 is here also continuous with the fascia transversalis. Superiorly it 

 forms the external arcuate ligament, which extends between the 

 last rib and the tip of the first Ivunbar transverse process. Inferiorly 

 it is attached to the ilio-lumbar ligament and the contiguous part 

 of the inner lip of the iliac crest. The middle lamina, which is of 

 considerable strength, is attached internally to the tips of the 

 lumbar transverse processes, and externally, at the outer border of 

 the quadratus lumborum, it is joined by the anterior lamina, whilst 

 at the outer border of the erector spinae it receives the posterior 

 lamina. Superiorly it is attached to the lower border of the last 

 rib, and inferiorly to the back part of the summit of the iliac crest. 

 The middle lamina lies between the quadratus limiborum and the 



