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inguinal ring and note that the space (i.e. the inguinal canal) occupied by 

 the spermatic cord is bounded posteriorly by the inguinal ligament and 

 anteriorly, by the M. obliquus internus; note also that the length of the 

 canal from the external inguinal ring to the level of the peritoneal ring, 

 measured along the spermatic cord, is about lo cm. 



A. iliaca externa (PI. V, 30) arises from the aorta at the level of the 5th 

 lumbar vertebra and extends obliquely ventrally, at the side of the pelvic 

 inlet, to the level of the anterior edge of the pubis where it is continued 

 as the A. femoralis. Remove the overlying peritoneimi and fascia. Note 

 that the large V. iliaca externa is immediately posterior to the artery. The 

 termination of the A. iliaca externa and the beginning of the A. femoralis 

 is indicated by the truncus pudendo-epigastricus or prepubic artery. 



Truncus pudendo-epigastricus or prepubic artery (PI. V, 31) is only 6 to 8 cm. 

 in length. It arises from the A. iliaca externa near the level of the anterior 

 border of the pubis. The artery crosses the dorsal or free edge of the 

 inguinal ligament and extends for a short distance along the abdominal or 

 anterior face of the ligament to the internal inguinal ring where it divides 

 into two branches— A. epigastrica caudalis or posterior abdominal and A. 

 pudenda externa or external pudic. 



(i) A. epigastrica caudalis (or posterior abdominal). 



This branch of the pudendo-epigastric trunk extends cephalad along 

 the lateral border of the M. rectus abdominis to which it is principally dis- 

 tributed; small twigs however, are also supplied to the transversus ab- 

 dominis and the obliquus internus. The artery is accompanied by a vein. 



(2) A. pudenda externa (or external pudic). 



This artery and its branches may be readily exposed by dissecting, 

 en masse, the sheath and penis from the abdominal wall as far back as to 

 the external inguinal ring taking care not to cut the artery as it emerges 

 from the ring at the postero-internal commissure. 



The A. pudenda externa is from 4 to 6 cm. in length. Immediately after 

 it passes through the external inguinal ring it divides into two branches — 

 the A. abdominalis subcutanea and the A. dorsalis penis. Trace the former 

 cephalad, along the side of the sheath, to which and to the superficial inguinal 

 lymph gland it is distributed. The dorsal artery of the penis passes to the 

 dorsum of that organ and terminates at the glans penis. It gives off col- 

 lateral branches to the corpus cavernosum one of which usually passes 

 posteriorly and anastomoses with a branch of the A. obturatoria. In the 

 female the mammary artery takes the place of the dorsal artery of the penis. 

 Note that the enormous venous plexus on the dorsal and lateral sides of the 



