ILIAC ARTERIES. 



831 



rather to be continuous with the last branch 

 arising from it. A variable number of branches 

 arise from it ; these are generally the superior 

 vesical, at times the vaginal or the uterine ; and 

 according to their number and size its size 

 varies ; it is not destined to any part, but only 

 gives rise to these branches, being in reality not 

 a branch of the iliac but so much of the vessel, 

 originally the umbilical or placental, as inter- 

 venes between the origin of the great branches 

 and the point at which it becomes impervious, 

 which remains open because of the origin of 

 the vesical arteries, &c. from it, but is thus re- 

 duced in size because of their minuteness. 



6. The uterine artery arises either from the 

 anterior division of the iliac, or from the pudic, 

 or at times from the umbilical ; it runs forward, 

 inward, and somewhat downward, until it 

 reaches the superior lateral part of the vagina, 

 and entering the broad peritoneal fold of the 

 uterus it ascends in it along the lateral region 

 of the uterus in a very tortuous manner, its 

 tortuosity increasing as it proceeds. As it as- 

 cends, it gives off a considerable number of 

 transverse branches, which attach themselves 

 to both surfaces of the organ, penetrate its 

 substance, and supply it with blood, anasto- 

 mosing, at the same time, freely with those 

 from the other side. When it has reached the 

 attachment of the ligament of the ovary, the 

 artery anastomoses with the spermatic artery. 

 Before the artery attaches itself to the uterus, it 

 gives a considerable branch to the vagina, which 

 descends along it to a greater or less extent 

 and is distributed to both its aspects. Branches 

 also go from it to the Fallopian tube, the round 

 ligament, and the ligament of the ovary, and 

 likewise communicate with branches of the 

 spermatic. 



The uterine artery in the unimpregnated con- 

 dition of the uterus is a small vessel, little, if at 

 all, larger than the hemorrhoidal or vesical 

 arteries, but during impregnation, and the more 

 so in proportion as that state advances, it un- 

 dergoes a remarkable change, becoming greatly 

 enlarged, so much so as to equal or exceed in 

 size any of the other branches of the internal 

 iliac ; and at the same time assuming a most 

 tortuous arrangement as well in its branches as 

 in its trunk. 



7. The vaginal artery arises also, when pre- 

 sent, from the anterior division of the iliac, or 

 from the pudic, the uterine, the umbilical, or 

 hemorrhoidal ; it is therefore very irregular and 

 often absent, its place being supplied by 

 branches from others. It runs forward and 

 downward along the side of the vagina, dis- 

 tributing branches to it, and also to the bladder 

 and rectum. At the extremity of the vagina it 

 terminates in the external genital organs, and 

 communicates with the branches of the pudic 

 artery. 



The external branches of the internal iliac 

 artery are four, viz. 



1 . The obturator or thyroid artery, (artere 

 sous-pubio-femorale, Chauss.) is a vessel of con- 

 siderable size, inferior only to the gluteal, pu- 

 dic, and sciatic branches, and about equal to 

 the epigastric artery, but irregular in that as 



well as in other respects. It arises most fre- 

 quently from the posterior division of the 

 internal iliac or from the iliac itself imme- 

 diately before its division ; it runs forward and 

 somewhat downward along the lateral wall of 

 the pelvis toward the superior posterior part of 

 the subpubic or thyroid foramen, through 

 which it escapes from the pelvis into the supe- 

 rior internal part of the thigh. The course of 

 the vessel may be divided into three parts : 

 1st, that within the pelvis ; 2d, that in the sub- 

 pubic canal ; 3d, that in the thigh. Within 

 the pelvis the artery is nearly parallel to the 

 brim of the pelvis, or ilio-pectineal line, and 

 from one-half to three-fourths of an inch be- 

 neath it, it holds a similar relation to the exter- 

 nal iliac vessels, which are above the line and 

 from which it is distant from three-fourths of an 

 inch to one and one-fourth. It is accompanied 

 by the obturator vein and nerve, and is placed 

 between them, the nerve being above and the 

 vein beneath it. It is situate within the pelvic 

 fascia; externally it rests against this fascia 

 above the origin of the levator ani muscle, and 

 separated by it from the internal obturator 

 muscle ; internally it corresponds in front to 

 the side of the bladder to an extent proportioned 

 to the degree to which that viscus may be dis- 

 tended, and is connected to it by cellular sub- 

 stance ; posteriorly it corresponds to the peri- 

 toneum of the pelvis, the ureter, and at times 

 to the anterior division of the iliac artery or 

 some of its other branches. In this part of its 

 course it gives off a branch which ascends to 

 the iliacus and psoas, branches to the obtura- 

 tor internus, to the lymphatic glands of the 

 pelvis and the bladder ; lastly, as it approaches 

 the subpubic foramen it gives an important 

 branch, which ascends posterior to the pubis, 

 distributes small branches as it proceeds, and 

 ends in an anastomosis with a branch, which 

 descends from the epigastric artery. Harrison 

 has occasionally found a considerable branch 

 given off in this situation, which passed to the 

 side of the prostate and the perineum, supply- 

 ing the place of deficient branches of the pudic 

 artery. 



In escaping from the pelvis the artery is 

 contained in an oblique canal leading inward 

 and forward. This canal, the subpubic, is 

 bounded superiorly and externally by the pu- 

 bis, which presents on the under surface of its 

 horizontal ram us an oblique channel, by which 

 the roof of the canal is formed ; inferiorly and 

 internally it is bounded by the margins of the 

 obturator muscles and ligament; toward the 

 pelvis it presents a defined aperture circum- 

 scribed above by the pubis and below by the 

 pelvic fascia, the attachment of which to the 

 bone is interrupted at the part at which the 

 artery passes out, and which describing a 

 curve beneath the vessels, between its points 

 of attachment at either side contributes thus to 

 form a rounded aperture through which they 

 escape without perforating the fascia; a thin 

 prolongation of the fascia is detached from it 

 beneath the vessels into the canal. Hernia 

 occasionally protrudes through this canal, and 

 the artery has been found by Cooper behind 



