202 



PRACTICAL ANATOMY. 



with its base toward the linea alba ; this is the 

 external inguinal ring. 

 Nerves Ilio-lumbar and ilio-hypogastric. 

 INTERNAL OBLIQUE. 



Origin Outer half of Poupart's ligament, anterior 

 half of crest of ilium, and lumbar fascia, 



FIG. 89. MUSCLES OF THE ABDOMEN. 



12, external oblique ; 16, rectus abdominis; 17, pyramidalis ; 18, internal oblique; 

 19, quadratus lumbornra. 



Insertion The iliac fibres are inserted into the three 

 lower ribs ; those from Poupart's ligament pass 

 upward and inward, become aponeurotic, the 

 aponeurosis reaches the outer border of the rectus 

 muscle and splits, forming the sheath for the rectus 

 (one leaflet passing in front, the other behind). 

 The inner or lower fibres arch upward and out- 

 ward, become aponeurotic ; the aponeurosis joins 



