Reference > Anatomy of the Human Body > Page 617
  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 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.

Peculiarities.—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 (Fig. 541 A); 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 (Fig. 541 B), 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.

FIG. 541– Variations in origin and course of obturator artery. (See enlarged image)

  The internal pudendal artery (a. pudenda interna; internal pudic artery) is the smaller of the two terminal branches of the anterior trunk of the hypogastric, and supplies the external organs of generation. Though the course of the artery is the same in the two sexes, the vessel is smaller in the female than in the male, and the distribution of its branches somewhat different. The description of its arrangement in the male will first be given, and subsequently the differences which it presents in the female will be mentioned.
  The internal pudendal artery in the male passes downward and outward to the lower border of the greater sciatic foramen, and emerges from the pelvis between the Piriformis and Coccygeus; it then crosses the ischial spine, and enters the perineum through the lesser sciatic foramen. The artery now crosses the Obturator internus, along the lateral wall of the ischiorectal fossa, being situated about 4 cm. above the lower margin of the ischial tuberosity. It gradually approaches the margin of the inferior ramus of the ischium and passes forward between the two layers of the fascia of the urogenital diaphragm; it then runs forward along the medial margin of the inferior ramus of the pubis, and about 1.25 cm. behind the pubic arcuate ligament it pierces the inferior fascia of the urogenital diaphragm and divides into the dorsal and deep arteries of the penis.


