THE OBTURATOR ARTERY; 



443 



terminal branches. In its course through the pelvis, the artery is 

 placed between the pelvic fascia and the peritoneum, a little below the 

 obturator nerve. Beneath the pubis it lies with its accompanying vein 

 and nerve in an oblique canal, formed partly by a groove in the bone, 

 and partly by fibrous tissue, after passing through which it divides 

 immediately into an external and an internal branch, which are deeply 

 placed behind the external obturator muscle. 



Branches. — (a) Within the pelvis, besides others of smaller size, tlie obturator 

 artery often supplies a branch to the iliac fossa and muscle, and one which rans 

 backwards upon the urinaiy bladder. 



(i) Anastomotic vessels, which may be cslladt. i)Hhic, are given off by the obtu- 

 rator artery as it is about to escape from the pelvis : these vessels ramify on the 

 back of the pubis, and communicate behind the bone and the attachments of the 

 abdominal muscles, with small offsets from the epigastric artery. These anasto- 

 mosing branches lie to the inner side of the cnu-al ring. 



Fiff. 284. 



=^=V. 



Fig. 284, A. and B.— Views 

 OF THE Left Wall of the 

 Pelvis, with the attached 

 abuomixal muscles fkom 

 the inside, showing dif- 

 feuent positions of the 

 Aberrant OiiTURATOR Ar- 

 teries (,from 11. Quain). -]- 



In A, a case is represented 

 in which the aberrant arterj- 

 passes to the outside of a 

 femoral hernia ; in B. an in- 

 stance is shown in which it 

 surrounds the neck of the sac. 



a, posterior surface of the 

 rectus muscle ; h, iliacus in- 

 temus muscle ; c, symphysis 

 pubis ; d, obturator mem- 

 braae ; e, placed on the fascia 

 transversalis, points to the vas 

 deferens passing through the 

 internal inguinal aperture ; /, 

 the testicle ; +, the neck of a 

 femoral hernial sac ; 1, the 

 external iUac artery ; 2, the ex- 

 ternal iliac vein ; below 2, the 

 obturator nerve ; 3, the deep 

 epigastric artery ; 4, aberrant 

 obturator artery, arising from 

 the epigastric. 



(c) The intertial terminal 

 branch cui-ves inwards be- 

 neath the obturator exter- 

 nus, close to the inner margin 

 of the thyroid foramen, and 

 furnishes branches to the 

 obturator muscles, the gracilis, and the adductor muscles. 



{d) The external terminal branch has a similar arrangement near the outer 

 margin of the thyroid foramen ; it descends as far as the' ischial tuberosity, and 

 supplies the obturator muscles, and the upper ends of the long muscles which 

 are attached to that tuberosity. This branch usually sends off a small arteiy, 

 which enters the hip-joint through the cotyloid notch, and ramifies in the 

 synovial fatty tissue, and along the round ligament as far as the head of the 

 lemur. 



