476 



THE ARTERIES OF THE ABDOMEN. 



branch which ramifies in the iliac fossa, supplying the ilio-psoas muscle and anasto- 

 mosing with the ilio-lumbar artery. 



(b) One or two small pubic branches are given off by the artery as it is about to 

 leave the pelvis : these vessels ramify on the back of the pubis, and communicate 

 behind the bone and the attachments of the abdominal muscles with the pubic 

 branch of the epigastric artery, and with the corresponding offsets of the oppo- 

 site side. 



(c) The internal terminal branch, turning downwards close to the inner margin 

 of the thyroid foramen, furnishes offsets to the obturator muscles and to the upper 



Fig. 381, A. and B. VIEWS OP THE LEFT 



HIP-BONE, WITH THE ATTACHED ABDO- 

 MINAL MUSCLES, FROM THE INSIDE, 

 SHOWING DIFFERENT POSITIONS OF 

 THE ABERRANT OBTURATOR ARTERY. 



(R. Quain.) \ 



In A, the aberrant artery passes to the 

 outer side of a femoral hernia ; in B, it sur- 

 rounds the neck of the sac. 



a, rectus muscle ; b, iliacus ; c, symphysis 

 pubis ; d, obturator membrane ; e, on the 

 transversalis fascia, points to the vas deferens 

 passing through the internal abdominal ring ; 

 /, testicle ; + , neck of a femoral hernial sac ; 

 1, external iliac artery ; 2, external iliac 

 vein ; below 2, the obturator nerve ; 3, 

 epigastric artery, giving off 4, the aberrant 

 obturator artery. 



ends of the adductors, and anasto- 

 B moses with branches of the internal 

 circumflex artery. 



(d) The extwnal terminal branch 

 descends near the outer margin of 

 the thyroid foramen, sends a small 

 offset inwards to anastomose with 

 the lower part of the internal branch, 

 and then, inclining outwards in the 

 groove below the acetabulum, is 

 distributed to the muscles arising 

 from the ischial tuberosity and 

 anastomoses with branches of the sciatic artery. It also gives twigs to the obtu- 

 rator muscles ; and one small branch, entering the hip-joint through the cotyloid 

 notch, supplies the fat and synovial membrane at the bottom of the acetabulum, and 

 is continued in the interarticular ligament to the head of the femur. 



Varieties. The obturator artery very frequently has its origin transferred to the com- 

 mencement of the epigastric artery (nearly 30 per cent.), and occasionally to the external iliac 

 near its termination (T2 per cent.) ; of it may arise by two roots, one from the internal iliac 

 and the other from the epigastric (3'6 per cent.). 1 Sometimes the obturator artery arises 

 from the epigastric on both sides of the same body, but in the majority of instances the 

 irregular origin exists only on one side. It may be said that in two out of every five subjects 

 the obturator artery is arising from the epigastric on one or both sides. The epigastric origin 

 is somewhat more common in the female than in the male ; and the origin by two roots is 



1 W. Pfitzner, " Ueber die Ursprungsverhaltnisse der Arteria obturatoria," Anatom. Anzeiger, iv, 

 1889 ; S. Jastschinski, "Die Abweichungen der Arteria obturatoria nebst Erklarung ihres Entstehens," 

 Internat. Monatschr. f. Auat. u. Phys., viii, 1891. 



