| sacral plexus | Formed by the fourth and fifth lumbar (lumbosacral trunk) and first, second, and third sacral nerves; it lies on the inner surface of the posterior wall of the pelvis usually embedded in the piriformis muscle; its nerves supply the lower limbs, its major product being the sciatic nerve. Synonym: plexus sacralis, ischiadic plexus, sciatic plexus. (05 Mar 2000) |
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| sacral promontory | The most prominent anterior projection of the base of the sacrum. Synonym: pelvic promontory, promontorium ossis sacri, promontory of the sacrum. (05 Mar 2000) |
| sacral region | The area of the back overlying the sacrum. Synonym: regio sacralis. (05 Mar 2000) |
| sacral splanchnic nerves | Branches from the sacral sympathetic trunk that pass to the inferior hypogastric plexus; part of the abdominopelvic (sympathetic) splanchnic nerves, but their specific function is unclear. They tend to be confused with the pelvic splanchnic nerves, which are much more significant structures. Synonym: nervi splanchnici sacrales. (05 Mar 2000) |
| sacral triangle | The surface area over the sacrum. (05 Mar 2000) |
| sacral tuberosity | A rough prominence on the lateral surface of the sacrum posterior to the auricular surface for attachment of posterior sacroiliac ligaments. Synonym: tuberositas sacralis. (05 Mar 2000) |
| sacral veins | See: lateral sacral veins, median sacral vein. (05 Mar 2000) |
| sacral venous plexus | A venous plexus on the pelvic surface of the sacrum, formed by tributaries to the lateral sacral veins. Synonym: plexus venosus sacralis. (05 Mar 2000) |
| sacral vertebrae | The segments of the vertebral column, usually five in number, that fuse to form the sacrum. Synonym: vertebrae sacrales. (05 Mar 2000) |
| intermediate sacral crests | Crests formed by the fusion of articular processes of all the sacral vertebrae. Synonym: articular crests, cristae sacrales intermediae. (05 Mar 2000) |
| lateral sacral artery | <anatomy, artery> Usually one of two arteries which arise from the internal iliac artery or its branches; they supply muscles and skin in the neighborhood and send branches into the sacral canal, supplying radicular and spinal arteries, and continuing on to the skin and subcutaneous tissues overlying the sacrum. Synonym: arteria sacralis lateralis. (05 Mar 2000) |
| lateral sacral crests | Crests which are rough ridges lying lateral to the sacral foramina; they represent the fused transverse processes of sacral vertebrae. Synonym: cristae sacrales laterales. (05 Mar 2000) |
| lateral sacral veins | Several veins that receive the drainage of the sacral venous plexus and sacral intervertebral veins then accompany the corresponding artery and empty into the internal iliac vein on each side. Synonym: venae sacrales laterales. (05 Mar 2000) |