Median sagittal section of the sacrum
About this plate
Median sagittal section of the sacrum.
The sacrum is a large triangular bone formed by the fusion of five sacral vertebrae, wedged between the two iliac bones and articulating superiorly with the fifth lumbar vertebra and inferiorly with the coccyx. In median sagittal section its anterior surface is concave and its posterior surface convex, with transverse ridges marking the lines of vertebral fusion. The sacral canal, a continuation of the vertebral canal, runs longitudinally and terminates below at the sacral hiatus. The coccyx, composed of three to five rudimentary vertebrae, projects downward and slightly forward, articulating with the sacral apex through a small fibrocartilaginous disc.
Source: After Gray's Anatomy (1918). Public domain (Gray's Anatomy, 1918), modernized rendering.
Rendering © 2026 Neuro.Wiki — recolouring, relabelling and three-dimensional modelling. The underlying historical figure is public domain and remains so. Free to view and to cite with a link; not licensed for redistribution, dataset compilation, or AI model training.