Sacrum Bone

Description

Centered in anatomical position, the female sacrum is presented from the anterior (pelvic) aspect, with the pelvic girdle highlighted for orientation against the rest of the skeleton. The sacral promontory forms the anterosuperior margin where S1 meets the body of L5, while the broad alae expand laterally toward the sacroiliac region. Four paired anterior sacral foramina punctuate the concave pelvic surface, separated by transverse ridges that mark the fused sacral vertebral bodies, and the bone tapers inferiorly to the apex where it meets the coccyx. Anterior sacral anatomy matters because it frames the pelvic inlet and the obstetric conjugate, and subtle differences in sacral curvature and promontory projection can influence pelvic dimensions discussed in childbirth mechanics. Those anterior foramina transmit ventral rami of S1 to S4, so sacral fractures or pelvic ring disruptions can correlate with radicular pain, bowel or bladder symptoms, and sexual dysfunction depending on the level involved. For procedural planning, the pelvic surface sits immediately posterior to the presacral space and anterior to sacral nerve roots, a relationship that informs anterior approaches to the lumbosacral junction and risk discussions around presacral hemorrhage or neural injury. Use this artwork in gross anatomy and pelvis-perineum teaching blocks to pair bony landmarks with dermatomes and pelvic floor innervation, and in OB-GYN or orthopaedic content discussing pelvic inlet assessment, sacroiliac joint pathology, and sacral fracture classification. It also fits radiology primers when correlating the anterior sacral foramina and promontory with AP pelvis radiographs and CT reformats. Anatomical accuracy verified by SciePro's Medical Advisory Board.