OF THE ABDOMEN 



433 



vessels and nerves, the iliohypogastric and the ilioinguinal nerves. Xear Poupart's ligament 

 the Cremaster lies on the fascia transversalis, internal ring, and spermatic cord. Its lower 

 border forms the upper boundary of the spermati' canal. 



Dissection. Detach the Internal oblique in order to expose the Transversalis beneath. This 

 may be effected by dividing the muscle, above, at its attachment to the ribs: belong at its con- 

 nection with Poupart's ligament and the crest of the ilium; and behind, by a vertical incision 

 extending from the last rib to the crest of the ilium. The muscle should previously be made 



Linea alba. 



FIG. 326. The Transversalis, Rectus. and Pyramidalis muscles. 



tense by drawing upon it with the ringers of the left hand, and if its division be carefully effected, 

 the cellular interval between it and the Transversalis, as well as the direction of the fibres of the 

 latter muscle, will afford a clear guide to their separation; along the crest of the ilium the cir- 

 cumflex iliac vessels are interposed between them, and form an important guide in separating 

 them. The muscle should then be thrown inward toward the linea alba. 



The Transversalis muscle (m. transversus abdomuus) (Fig. 326), so called 

 from the direction of its fibres, is the deepest flat muscle of the abdominal wall, 



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