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ILIAC ARTERIES. 



division of the internal iliac, at times from the 

 iliac itself; at times from the gluteal, occa- 

 sionally from the primitive iliac, and frequently 

 by a trunk common to it and the lateral sacral ; 

 from its origin, which is somewhat below the 

 base of the sacrum, it runs upward, outward, 

 and backward toward the iliac fossa, passes in 

 front of the sacro-iliac articulation and the 

 lumbo-sacral nerve and external to the obturator 

 nerve; having surmounted the outlet of the 

 pelvis it passes behind the psoas muscle, the 

 external iliac vessels and the anterior crural 

 nerve, and emerges from behind them at the 

 superior and internal part of the fossa, where it 

 divides. As the artery emerges from the pelvis 

 it gives off a branch which descends along the 

 brim, gives small branches to the inside of the 

 psoas, and finally anastomoses with a branch 

 from the epigastric artery ; while concealed by 

 the psoas it gives branches to it and the iliacus 

 internus. Finally it divides into two sets of 

 branches, superior or ascending, and external or 

 transverse ; the former ascend beneath the 

 psoas, supply it, the iliacus and the quadratus 

 lumborum, send a branch into the vertebral 

 canal through one of the inferior intervertebral 

 foramina, and finally communicate with the 

 inferior lumbar arteries. The external set pass 

 outward into the iliac fossa, and are distin- 

 guished into two, a superficial and deep ; the 

 former run across the iliacus muscle, superficial 

 to it and beneath the iliac fascia, supply the 

 muscle and anastomose freely with corres- 

 ponding t branches from the circumflex branch 

 of the external iliac artery : the superior of the 

 superficial branches runs round the crest of the 

 ilium within its inner edge, as it proceeds it 

 gives branches downward to the iliacus and 

 upward to the quadratus lumborum, the trans- 

 versalis and oblique muscles, some of which 

 turn over the crest and communicate with 

 branches of the gluteal artery ; finally it ends in 

 a direct and free anastomosis with the ultimate 

 branch of the circuinflex artery, the fossa having 

 thus an artificial circle formed around it in- 

 ternally, between these branches and the original 

 iliacs. The branches of the deep set pass into 

 the substance of the iliacus muscle, and between 

 it and the bone, and are distributed to the 

 muscle, the periosteum, and the bone, one of 

 them entering the ilium through the canal to be 

 observed at the bottom of the fossa ; their deep 

 branches also communicate with the circumflex 

 iliac, the gluteal and the external circumflex 

 femoral arteries. Sometimes there are two 

 ilio-lumbar arteries. 



2. The lateral sacral artery may be either 

 single or double, and arises either from the 

 posterior division of the iliac, from the iliac 

 itself on its inner side, from the gluteal, or the 

 sciatic, and frequently in common with the 

 ilio-lumbar : it runs downward, and inward in 

 front of the lateral part of the sacrum, the sacral 

 nerves at their exit from the anterior sacral 

 foramina, and the pyriform muscle external to 

 the middle sacral artery and the sympathetic 

 nerve ; it descends to the extremity of the 

 sacrum and then anastomoses with the middle 

 sacral and the artery of the other side ; at times 



instead of terminating thus it enters the sacral 

 canal through the third or fourth foramen and 

 is distributed internally. Its branches are dis- 

 tinguished into two sets, an anterior or internal 

 and a posterior or external. The former are 

 distributed to the sacral nerves within the 

 pelvis, to the pyriform muscle, to the pelvic 

 cellular tissue and glands, to the levator ani 

 muscle and to the sacrum. The posterior are 

 the larger, they are usually four, but at times 

 more numerous, two branches sometimes taking 

 the same course; they pass backward along 

 the sacral nerves, through the sacral foramina, 

 into the canal, and then divide into two, of 

 which one is distributed within the canal to the 

 nerves and their ganglia, to the membranes and 

 the sacrum ; the other escapes backward 

 through the posterior sacral foramen, and is 

 distributed upon the back of the sacrum in the 

 sacro-vertebral channel, anastomosing with the 

 adjoining vessels. 



3. The middle hemorrhoidal artery is some- 

 times wanting, its place being supplied by 

 branches from the other divisions of the iliac ; 

 it is of about the same size as the previous 

 arteries, and varies very much in its source, 

 arising from the anterior division of the iliac, 

 from that vessel itself or from the pudic, the 

 sciatic or lateral sacral arteries, it runs down- 

 ward, forward, and inward along the side and 

 front of the rectum, at first between the intes- 

 tine and the levator ani, and then between it 

 and the fund us of the bladder in man and the 

 vagina in the female, and divides into branches, 

 of which the greater part are distributed to the 

 rectum, anastomosing with the branches of the 

 superior hemorrhoidal from above and with 

 those of the inferior hemorrhoidal from below ; 

 others are distributed to the fundus of the 

 bladder, the prostate and vesiculae in man, and 

 to the vagina in the female. 



4. The vesical arteries are subject to great 

 variety ; they are numerous and smaller than 

 the last described : they are distinguished by 

 Harrison into three sets, inferior, middle, and 

 superior ; the inferior set consists of those 

 branches given to the fundus of the bladder by 

 the middle hemorrhoidal, pudic, and sciatic 

 arteries; the superior, furnished by the um- 

 bilical, are two or more in number, and are 

 distributed to the superior region of the bladder, 

 but the middle is a single vessel larger than 

 the others, and given off by the iliac artery, 

 though frequently arising from some of its 

 branches, particularly the umbilical : it is en- 

 titled by Chaussier " vesico-prostatique :" it 

 passes downward and inward to the fundus of 

 the bladder, and then divides into branches 

 distributed to the bladder, and in the male also 

 to the prostate, the vesicular and neck of the 

 bladder. 



5. The umbilical artery. In the adult sub- 

 ject a small arterial canal usually from an inch 

 and a half to two inches and a half long ex- 

 tends from the termination of the internal iliac, 

 or from one of its branches to the superior 

 lateral part of the bladder ; there it is continued 

 with, or seems to have attached to it superiorly 

 the umbilical ligament, the artery appearing 



