Outer spiral sulcus
Sulcus spiralis externus
Definition
The periosteum, forming the outer wall of the ductus cochlearis, is greatly thickened and altered in character, and is called the spiral ligament. It projects inward below as a triangular prominence, the basal crest, which gives attachment to the outer edge of the basal lamina; immediately above the crest is a concavity, the sulcus spiralis externus.
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/).
