Spina vestibuli

Spina vestibuli
Interior of dorsal half of heart from a human embryo of about thirty days. (Spina vestibuli labeled at center left.)
Anatomical terminology []

Below the opening of the orifice of the coronary sinus they fuse to form a triangular thickening—the spina vestibuli.

This article incorporates text in the public domain from the 20th edition of Gray's Anatomy (1918)