296 SMALLER BRANCHES OF THE INTERNAL ILIAC. 



the membranes which invest it. Some of their ramifications 

 anastomose with branches of the sacra media and other con- 

 tiguous arteries. 



On the anterior side of the internal iliac, near the origin of 

 the above mentioned vessels, a ligament, which was originally 

 the umbilical artery, goes off to the side of the bladder, and 

 continues from thence to the umbilicus. Sometimes it con- 

 tinues previous for a short distance, and then small branches 

 pass from it to the bladder. 



In the female it also sends small branches to the uterus and 

 vagina. 



In addition to these Vesical Arteries derived from the umbi- 

 licals, there are other branches distributed to the bladder, which 

 arise very differently, in different subjects, from branches 

 which are soon to be described, as the hemorrhoidal, pudic, &c. 



From the anterior side of the internal iliac, or from one of 

 its great branches, an artery arises which passes out of the 

 pelvis through the aperture in the margin of the ligamentous 

 membrane which closes the foramen thyroideum of the os 

 innominatum ; this is called the 



Obturator Artery. 



This vessel, while it is in the pelvis, often sends small branches 

 to the bladder and its appendages, and to the obturator internus 

 muscle. After it passes out of the pelvis, it divides into 

 branches ; some of which are spent on the obturator externus, 

 and the contiguous muscles, and others go to the hip joint. 

 — One branch of the artery called internal, is distributed in 

 the adductor, gracilis and pectineus muscles which are placed 

 on the inner side oC the thigh. — The origin of this artery is 

 variable. Most commonly it arises from the internal iliac, but 

 often from the ischiatic, and sometimes from the gluteal. In 

 some instances, it originates in a way that is particularly inte- 

 resting, when the operation for crural hernia is to be performed, 

 viz. from the epigastric artery, soon to be described .' for in 

 this case the obturator artery sometimes nearly surrounds the 



