INTERNAL ILIAC ARTERY. 



317 



INTERNAL ILIAC ARTERY. 



The Internal Iliac artery is a short trunk, varying in length from an 

 inch to two inches. It descends obliquely to a point opposite the upper 

 margin of the great sacro-ischiatic foramen, where it divides into an ante- 

 nor and a posterior trunk. 



Fig. 156. 



Relations. This artery rests externally on the sacral plexus and on the 

 origin of the pyriformis muscle ; posteriorly it is in relation with the in- 

 ternal iliac vein, and anteriorly with the ureter. 



Branches. The branches of the anterior trunk are the 



Umbilical, 

 Middle vesical, 

 Middle hsemorrhoidal, 



And in the female the 



Uterine, 

 And of the posterior trunk, the 



Ilio-lumbar, 

 Obturator, 



Ischiatic, 

 Internal pudic. 



Vaginal. 



Lateral sacral, 

 Gluteal. 



The umbilical artery is the commencement of the fibrous cord into 

 which the umbilical artery of the foetus is converted after birth. In after 

 life, the cord remains pervious for a short distance, and constitutes the 

 umbilical artery of the adult, from which the superior vesical artery is 

 given off to the fundus and anterior aspect of the bladder. The cord may 



*The distribution and branches of the iliac arteries. 1. The aorta. 2. The left com- 

 mon iliac artery. 3. The external iliac. 4. The epigastric artery. 5. The circumflexa 

 ilii. 6. The internal iliac artery. 7. Its anterior trunk. 8. Its posterior trunk. 9. The 

 umbilical artery giving off (10) the superior vesical artery. After the origin of tins 

 branch, the umbilical artery becomes converted into a fibrous cord the umbilical liga- 

 ment. 11. The internal pudic artery passing behind the spine of the ischium (12) and 

 lesser sacro-ischiatic ligament. 13. The middle haemorrhoidal artery. 14. The ischiatic 

 artery, also passing behind the- anterior sacro-ischiatic ligament to escape from the 

 pelvis. 15. Its inferior vesical branch. 16. The ilio-lumbar, the first branch of the pos- 

 terior trunk (8) ascending to inosculate with the circumflexa ilii artery (5) and form aa 

 arch along the crest of the ilium. 17. The obturator artery. 18. The lateral sacral. 

 19. The gluteal artery escaping from the pelvis through the upper part of the great 

 sacro-ischiatic foramen. 20. The sacra media. 21. The right common iliac arteiy cu 

 ihort. 22. The femoral ar*ery. 



27* 



