vertebral (adj.)

"bone of the spine," early 15c., from Latin vertebra "joint or articulation of the body, joint of the spine" (plural vertebræ), perhaps from vertere "to turn" (from PIE root *wer- (2) "to turn, bend") + instrumental suffix -bra. The notion would be the spine as the "hinge" of the body.

suffix forming adjectives from nouns or other adjectives, "of, like, related to, pertaining to," Middle English -al, -el, from French or directly from Latin -alis (see -al (2)).