Assertion: sacrum's surface | /r/HasProperty | smooth
Facets:
Source sentences:
text: The posterior surface is smooth, and gives origin to the Obturator internus, and, close to the medial margin, to the Constrictor urethrae.
text: This concave surface is smooth and formed by the fused body of the sacral vertebra with four ridges persisting to mark the lines of ossification (intervertebral disc).
text: The pelvic surface faces anteriorly (front) and is smooth and concave.
text: The front (ventral) surface of the sacrum is concave and smooth whereas the back (dorsal) surface is convex and covered by five rough longitudinal ridges.