THE INTERNAL ILIAC ARTERY. 563 



in the main arterial trunk, and select his spot for the application of the ligature ; and (4) it 

 occupies much less time. 



Collateral Circulation. In Professor Owen's dissection of a case in which the internal 

 iliac artery had been tied by Stevens ten years before death for aneurism of the sciatic artery, 

 the internal iliac was found impervious for about an inch above the point where the ligature had 

 been applied, but the obliteration did not extend to the origin of the external iliac, as the ilio- 

 lumbar artery arose just above this point. Below the point of obliteration the artery resumed 

 its natural diameter, and continued so for half an inch, the obturator, lateral sacral, and gluteal 

 arising in succession from the latter portion. The obturator artery was entirely obliterated. 

 The lateral sacral artery was as large as a crow's quill, and had a very free anastomosis with the 

 artery of the opposite side and with the middle sacral artery. The sciatic artery was entirely 

 obliterated as far as its point of connection with the aneurismal tumor, but on the distal side of 

 the sac it was continued down along the back of the thigh nearly as large in size as the femoral, 

 being pervious about an inch below the sac by receiving an anastomosing vessel from the pro- 

 fiinda. The circulation was carried on by the anastomoses of the uterine and ovarian arteries; 

 of the opposite vesical arteries ; of the haemorrhoidal branches of the internal iliac with 

 those from the inferior mesenteric ; of the obturator artery, by means of its pubic branch, 

 with the vessel of the opposite side and with the epigastric and internal circumflex; of the 

 circumflex and perforating branches of the profunda lemoris with the sciatic ; of the gluteal 

 with the posterior branches of the sacral arteries ; of the ilio-lumbar with the last lumbar ; of 

 the lateral sacral with the middle sacral ; and of the circumflex iliac with the ilio-lumbar and 

 gluteal. 



BRANCHES OF THE INTERNAL ILIAC. 



From the Anterior Trunk. From the Posterior Trunk. 



. Superior Vesical. Ilio-lumbar. 



Middle Vesical. Lateral Sacral. 



Inferior Vesical. Gluteal. 



Middle Haemorrhoidal. 



Obturator. 



Internal Pudic. 



Sciatic, 

 f Uterine. 

 \Vaginal. 



The superior vesical is that part of the foetal hypogastric artery which remains 

 pervious after birth. It extends to the side of the bladder, distributing numerous 

 branches to the apex and body of the organ. From one of these a slender vessel 

 is derived which accompanies the vas deferens in its course to the testis, where it 

 anastomoses with the spermatic artery. This is the artery of the vas deferens. 

 Other branches supply the ureter. 



The middle vesical, usually a branch of the superior, is distributed to the base 

 of the bladder and under surface of the vesiculae seminales. 



The inferior vesical arises from the anterior division of the internal iliac, 

 frequently in common with the middle hsemorrhoidal, and is distributed to the 

 base of the bladder, the prostate gland, and vesiculae seminales. The branches 

 distributed to the prostate communicate with the corresponding vessel of the 

 opposite side. 



The middle hgemorrhoidal artery usually arises together with the preceding 

 vessel. It supplies the anus and parts outside the rectum, anastomosing with the 

 other hgemorrhoidal arteries. 



The uterine artery (Fig. 313) passes inward from the anterior trunk of the 

 internal iliac to the neck of the uterus. Ascending in a tortuous course on the 

 side of this viscus, between the layers of the broad ligament, it distributes branches 

 to its substance, anastomosing, near its termination, with a branch from the ovarian 

 artery. It gives off branches to the cervix uteri (cervical), and branches which 

 descend on the vagina, and, joining with branches from the vaginal arteries, form 

 a median longitudinal vessel both in front and behind ; these descend on the ante- 

 rior and posterior surfaces of the vagina, and are named the azygos arteries of the 

 vagina. 



1 Medico- Chirurgical Trans., vol. xvi. 



