Obturator artery
Arteria obturatoria
Definition
The obturator artery passes forward and downward on the lateral wall of the pelvis, to the upper part of the obturator foramen, and, escaping from the pelvic cavity through the obturator canal, it divides into an anterior and a posterior branch. In the pelvic cavity this vessel is in relation, laterally, with the obturator fascia; medially, with the ureter, ductus deferens, and peritoneum; while a little below it is the obturator nerve.
Branches of the obturator artery:
Inside the pelvis the obturator artery gives off:
Some iliac branches to the iliac fossa, which supply the bone and the Iliacus, and anastomose with the ilio-lumbar artery;
A vesical branch, which runs backward to supply the bladder
A pubic branch, which is given off from the vessel just before it leaves the pelvic cavity. The pubic branch ascends upon the back of the pubis, communicating with the corresponding vessel of the opposite side, and with the inferior epigastric artery.
Outside the pelvis, the obturator artery divides at the upper margin of the obturator foramen, into an anterior and a posterior branch which encircle the foramen under cover of the Obturator externus.:
The anterior branch runs forward on the outer surface of the obturator membrane and then curves downward along the anterior margin of the foramen. It distributes branches to the Obturator externus, Pectineus, Adductores, and Gracilis, and anastomoses with the posterior branch and with the medial femoral circumflex artery.
The posterior branch follows the posterior margin of the foramen and turns forward on the inferior ramus of the ischium, where it anastomoses with the anterior branch. It gives twigs to the muscles attached to the ischial tuberosity and anastomoses with the inferior gluteal. It also supplies an articular branch (acetabular branch) which enters the hip-joint through the acetabular notch, ramifies in the fat at the bottom of the acetabulum and sends a twig along the ligamentum teres to the head of the femur.
The obturator artery sometimes arises from the main stem or from the posterior trunk of the hypogastric, or it may spring from the superior gluteal artery; occasionally it arises from the external iliac. In about two out of every seven cases it springs from the inferior epigastric and descends almost vertically to the upper part of the obturator foramen. The artery in this course usually lies in contact with the external iliac vein, and on the lateral side of the femoral ring; in such cases it would not be endangered in the operation for strangulated femoral hernia. Occasionally, however, it curves along the free margin of the lacunar ligament, and if in such circumstances a femoral hernia occurred, the vessel would almost completely encircle the neck of the hernial sac, and would be in great danger of being wounded if an operation were performed for strangulation.
References
This definition incorporates text from a public domain edition of Gray's Anatomy (20th U.S. edition of Gray's Anatomy of the Human Body, published in 1918 – from http://www.bartleby.com/107/).