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are situated near the bifurcation of the A. circumfiexa ihaca. Dissect up 

 the peritoneum cephalad of the peritoneal or vaginal ring and note very 

 carefiilly the relation of this ring and the spermatic cord, to the posterior 

 edge of the M. obhquus intemus. Do not confuse the M. cremasteric 

 externa with the obhquus intemus. Transect the obhquus intemus a Httle 

 dorsal to the peritoneal ring. Now trace the anterior branch of the A. 

 circumfiexa iliaca. At, or near, its origin it may give off one or two small 

 branches to the psoas magnus and iliacus. About 5 cm. from its origin 

 this anterior branch divides into two branches which are distributed to 

 the Mm. transversus, abdominis obliquus internus and obliquus externus. 

 The posterior branch of the A. circumfiexa iliaca, 5 to 8 cm. from its origin, 

 also divides into two branches of which one goes to the obliquus internus 

 and the other, after perforating the abdominal wall near the external angle 

 of the ilium, runs downward on the inner face of the M. tensor fasciae latae, 

 about 5 cm. from its anterior border, and is distributed to the panniculus, 

 the precrural or subiliac lymph gland and to the inner face of the tensor 

 fasciae latae. To demonstrate this latter branch reflect the skin in the 

 region of the flank and dissect between the abdominal wall and the inner 

 face of the tensor fasciae latae. Find the artery (and vein) on the inner 

 surface of the tensor fasciae latae, 5 to 8 cm. from its anterior border, and 

 trace it in both directions. 



Internal inguinal ring. 



The internal inguinal ring should not be confused with the small peri- 

 toneal or vaginal ring of the male. The internal inguinal ring is from 10 

 to 12 cm. in length, measured from the prepubic tendon to the dorsal margin 

 of the peritoneal ring. The anterior boundary of the internal inguinal 

 ring is formed by the posterior edge of the M. obliquus intemus; the pos- 

 terior boundary is formed by the inguinal ligament. In the male the follow- 

 ing structures pass through the inguinal canal, viz., the evaginated peritoneum 

 of the spermatic cord, the ductus deferens or spermatic duct, the spermatic 

 nerves, artery and vein and lymph vessels, the A. pudenda externa and 

 the M. cremasteric externa. The skin in the region of the external inguinal 

 ring should now be carefully turned aside in order to expose the superficial 

 ingmnal lymph gland, the external inguinal ring and the structures which 

 pass through it. The superficial inguinal lymph gland forms a large mass, 

 8 to ID cm. long, which lies anterior to the external inguinal ring. In the male 

 the gland extends along the course of the A. abdominalis subcutanea on 

 either side of the penis; in the female the gland is situated between the 

 mammary gland and the abdominal wall. Now turn aside the portion of 

 the M. obliquus intemus that forms the anterior boundary of the internal 



