The neural arch consists of four articular processes, two superior along with two inferior. The superior processes protrude rather more from pedicles and articulate with the inferior articular processes of the vertebra above. The inferior articular processes articulate with superior articular processes of the vertebra below and spring from laminae.
Each vertebra has four articular processes:
- A right and left inferior articular process.
- A right and left superior articular process.
There is a smooth region of bone on the medial surface of each superior articular process in the intact spine which is enclosed with articular cartilage and on the lateral surface of each inferior articular process. This area is called the articular facet of each articular process.
The superior and inferior articular processes are located superior and inferior the junction of pedicle as well as lamina, along with the part of arch which separates these processes is called pars interarticularis.
Direction of Articular Surfaces
The direction of articular surfaces varies in cervical, thoracic as well as lumbar zone. The articular surfaces of inferior articular processes are pointed opposite towards those of superior articular processes.
The articular surfaces of superior articular processes face:
- Backwards and upwards in the cervical zone.
- Backwards and laterally in the thoracic zone.
- Backwards and medially in the lumbar zone.