A multilaminated ligament surrounding the periphery of each disc space, attaching, craniad and caudad, to end-plate cartilage and ring apophyseal bone and blending centrally with nucleus pulposus. Note: Either anulus or annulus is correct spelling. Nomina Anatomica uses both forms whereas Terminologia Anatomica states "anulus fibrosus." 18,21 Fibrosus, has no correct alternative spelling; fibrosis has a different meaning and is incorrect in this context. AJNR