Henry Gray (18251861). Anatomy of the Human Body. 1918.
The Cutaneous Branches are distributed to the skin of the buttock and back of the thigh.
The iliolumbar artery (a. iliolumbalis) a branch of the posterior trunk of the hypogastric, turns upward behind the obturator nerve and the external iliac vessels, to the medial border of the Psoas major, behind which it divides into a lumbar and an iliac branch.
The Lumbar Branch (ramus lumbalis) supplies the Psoas major and Quadratus lumborum, anastomoses with the last lumbar artery, and sends a small spinal branch through the intervertebral foramen between the last lumbar vertebra and the sacrum, into the vertebral canal, to supply the cauda equina.
The Iliac Branch (ramus iliacus) descends to supply the Iliacus; some offsets, running between the muscle and the bone, anastomose with the iliac branches of the obturator; one of these enters an oblique canal to supply the bone, while others run along the crest of the ilium, distributing branches to the gluteal and abdominal muscles, and anastomosing in their course with the superior gluteal, iliac circumflex, and lateral femoral circumflex arteries.
The lateral sacral arteries (aa. sacrales laterales) (Fig. 539)arise from the posterior division of the hypogastric; there are usually two, a superior and an inferior.
The superior, of large size, passes medialward, and, after anastomosing with branches from the middle sacral, enters the first or second anterior sacral foramen, supplies branches to the contents of the sacral canal, and, escaping by the corresponding posterior sacral foramen, is distributed to the skin and muscles on the dorsum of the sacrum, anastomosing with the superior gluteal.
The inferior runs obliquely across the front of the Piriformis and the sacral nerves to the medial side of the anterior sacral foramina, descends on the front of the sacrum, and anastomoses over the coccyx with the middle sacral and opposite lateral sacral artery. In its course it gives off branches, which enter the anterior sacral foramina; these, after supplying the contents of the sacral canal, escapes by the posterior sacral foramina, and are distributed to the muscles and skin on the dorsal surface of the sacrum, anastomosing with the gluteal arteries.