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A MANUAL OF ANATOMY 



anterior aponeurosis of the transversalis abdominis, in this 

 order from before backwards, all three being closely connected. 

 Ov&c this extent the sheath is deficient posteriorly, and the 

 muscle rests upon the fascia transversalis, with an exception to 

 be presently stated. The lower border of the posterior wall 

 presents a free curved margin, with the concavity downwards, 

 called the semilunar fold of Douglas, over which the deep 

 epigastric artery passes. This fold is usually situated about the 

 junction of the upper fourth and lower three-fourths of the 

 infra-umbilical portion of the linea alba. Sometimes the anterior 

 aponeurosis of the transversalis abdominis, though passing in 

 front of the lower fourth of the rectus, sends scattered fibres 

 behind it, which would thus intervene between the muscle 

 and the fascia transversalis for a variable distance below the fold 

 of Douglas. In such cases the posterior wall of the sheath 

 presents another curved semilunar fold, situated from i to 2 inches 

 below the semilunar fold of Douglas, and known as the band of 



Obliquus Externus Abdominis 

 Obllquus Internus Abdominis ._ ] 



Transversalis Abdominis 



Lumbar Fascia '•, 



Rectus Abdominis 



—Linea Alba 



""--.Fascia Transversalis 



Fig. 286. — Diagram showing the Sheath of the Rectus Abdominis. 

 A, Over the upper three-fourths ; B, over the lower fourth. 



Henle, over which the deep epigastric artery passes. The contents 

 of the sheath are as follows : the rectus abdominis, pyramidalis 

 abdominis, deep epigastric vessels, superior epigastric vessels, and 

 terminal parts of the lower five intercostal, and subcostal, nerves. 



Relation of Structures at the Pubic Crest. — The relation of structures from 

 before backwards is as follows : 



1. The triangular fascia. 



2. The conjoined tendon. 



3. The pyramidalis. 



4. The outer head of the rectus abdominis. 



5. The fascia transversalis. 



A few fibres of the cremaster are inserted into the pubic crest close to the 

 pubic spine. 



Relation of Structures at the Pectineal Portion of the Ilio-pectineal Line.— 

 The relation of structures from before backwards is as follows : 



I. The pubic laniina of the fascia lata, incorporated with which is the pubic 

 ligament of Cooper. 



i. The pectineus. 



3. Gimbernat's ligament. 



4. The conjoined tendon. 



5. The fascia transversalis and the deep femoral arch. 



