Transverse ridges
Lineae transversae
Definition
The middle part of pelvic surface of sacrum is crossed by four transverse ridges, the positions of which correspond with the original planes of separation between the five segments of the bone.
References
This definition incorporates text from a public domain edition of Gray's Anatomy (20th U.S. edition of Gray's Anatomy of the Human Body, published in 1918 – from http://www.bartleby.com/107/).
