The movable vertebræ form two sets of articulations, viz., those formed
by the bodies, and those formed by the articular processes of adjacent
vertebræ; the former are termed =intercentral=, and the latter,
=interneural=. Associated with these are ligaments uniting the arches
and processes; some of these are =special=, _i. e._, confined to a
single joint, while others are =common=, _i. e._, extend along the
entire vertebral column or a considerable part of it. The joints between
the atlas and axis and between the former and the skull require separate
consideration.