Pars lateralis processus transversi

The two transverse processes, one on each side of the vertebral body, project laterally from either side at the point where the lamina joins the pedicle, between the superior and inferior articular processes.

They also serve for the attachment of muscles and ligaments, in particular the intertransverse ligaments.

There is a facet on each of the transverse processes of thoracic vertebrae which articulates with the tubercle of the rib.

A facet on each side of the thoracic vertebral body articulates with the head of the rib.

The transverse process of a lumbar vertebra is also sometimes called the 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.