The Ligaments Connecting the Articular Processes

Class. - Diarthrosis. Subdivision. - Arthrodia.

The articular capsules which unite these processes are composed partly of yellow elastic tissue and partly of white fibrous tissue. In the cervical region only the medial side of the capsule is formed by the ligamenta flava, which in the thoracic and lumbar regions, however, extend anteriorly to the margins of the intervertebral foramina.

The part formed of white fibrous tissue consists of short, well-marked fibres, which in the cervical region pass obliquely downward and forward over the joint, between the articular processes and the posterior roots of the transverse processes of two contiguous vertebra. In the thoracic region the fibers are shorter, and vertical in direction, and are attached to the bases of the transverse processes; in the lumbar, they are obliquely transverse. The articular capsules in the cervical region are the most lax, those in the lumbar region are rather tighter, and those in the thoracic region are the tightest.

There is one synovial membrane to each capsule.