2 7 



THE ABDOMEN AND PELVIS 



Abscesses arising in connection with the vertebral column lie 

 between the fascial envelope of the abdomen (p. 271) and the 

 lumbo-dorsal fascia (Fig. 83). If the pus bursts through the 

 latter layer, it enters the upper lumbar triangle and then passes 

 downwards and laterally. Escaping from under cover of the 

 latissimus dorsi, it gains the lumbar triangle (of Petit) and points 

 above the iliac crest. 



Linea alba 



Rectus sheath, ant. wall 



Rectus sheath, post, wall 

 Transversalis fascia 



Peritoneum 



Duodenum, third part 

 Ascending colon 



I'eri-nephric 

 fascia 



Lumbo-dorsal 

 fascia 



Peri-nephric abscess 



Lumbo-dorsal f., ant. layer 

 Lumbo-dorsal f., middle layer 

 Lumbo-dorsal f., post, layer 

 Gerota's space 



FIG. 82. Diagram of a Transverse Section through the Abdomen, 



at the level of the Third Lumbar Vertebra. 



On the left side, the normal arrangement of the fasciae is shown. On the 

 right side, the course taken by a peri-nephric abscess is represented. The pus 

 has perforated the peri-nephric and the lumbo-dorsal fasciae, and, after passing 

 downwards and laterally, has appeared at the lateral border of the latissimus 

 dorsi in the lumbar triangle (of Petit). 



Abscesses which arise within the fascial envelope of the 

 abdomen tend to pass forwards round the abdominal wall in the 

 extra-peritoneal fat. 



The Quadratus Lumborum is a flat muscle arising below from the iliac 

 crest and the ilio-lumbar ligament, which extends between the crest and the 

 transverse process of the fifth lumbar vertebra. It becomes narrower as it 

 passes upwards to be inserted into the twelfth rib. Anteriorly, it is clothed 

 by the anterior lamella of the lumbo-dorsal fascia, which separates it from 

 the medial continuation of the fascia transversalis (p. 271). Both muscles 

 acting together produce extension of the vertebral column ; one, acting alone, 

 produces lateral flexion. The nerve-supply is derived from L. i, 2, 3, and 4. 



The Psoas Major occupies the groove between the bodies and transverse 

 processes of the lumbar vertebrae. It arises from the twelfth thoracic and all 

 the lumbar vertebras, and passes downwards and laterally along the margin 



