Transverse process
Processus transversus
Definition
The transverse processes, two in number, project one at either side from the point where the lamina joins the pedicle, between the superior and inferior articular processes. They serve for the attachment of muscles and ligaments.
The transverse process of a lumbar vertebra is also called costal or costiform process, because it corresponds to a rudimentary rib (costa) which, as opposed to the thorax, is not developed in the lumbar region.