Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 14 On the Spine and its Various Bones

Articulation of the vertebrae 33

Now because the spine needed to be formed from the vertebrae as a single body which would be at the same time firm, strong, and flexible, Nature deserves great praise for constructing a spine suitable for both (though contrary) uses. All the vertebrae down to the sacrum (except the first two) are safely bound to each other on their anterior portion (R, R) [discus intervertebralis] by large bodies, and on their posterior (N, O) they are fitted together by double joints [articulationes zygapophysiales], where they gain strength from the anterior structure. Thus the vertebrae are not kept from moving because they are not bound together at their bodies and they are kept separate in their posterior by clearly visible joints. For this reason we are readily able to bend forward but not at all backward. 34 For if you force the membraneous ligaments 35 that join the bodies of the vertebrae (R, R), you will break them along with the other cartilaginous ligament [discus intervertebralis] placed between the bodies of the vertebrae and thus connecting them, so that the vertebrae do not differ much from the tissues connected to it. The next Book will deal abundantly with the nature and substance of these ligaments, and all other matters.



Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 14 On the Spine and its Various Bones