Articular processes

Articular processes are anatomical structures found in the vertebral column. They are part of the vertebra and are crucial for the movement and flexibility of the spine.

Anatomy

Each vertebra in the spine has four articular processes: two superior and two inferior. The superior articular processes project upward from the vertebra, while the inferior articular processes project downward. These processes are paired on either side of the vertebra and are located at the junction of the vertebral arch and the vertebral body.

The articular processes of adjacent vertebrae articulate with each other to form the facet joints, also known as zygapophysial joints. These joints are synovial joints, meaning they are surrounded by a capsule of connective tissue and produce a lubricating synovial fluid. The surfaces of the articular processes are covered in hyaline cartilage, a type of connective tissue that reduces friction and absorbs shock.

Function

The articular processes and the facet joints they form play a crucial role in the movement of the spine. They allow for flexion and extension (bending forward and backward), lateral flexion (bending side to side), and rotation. The orientation of the articular processes varies in different regions of the spine, which affects the types of movement that are possible. For example, in the lumbar spine, the articular processes are oriented in the sagittal plane, which allows for flexion and extension but limits rotation.

Clinical significance

Conditions such as osteoarthritis can affect the articular processes and facet joints, leading to pain and reduced mobility. This is often due to the wear and tear of the hyaline cartilage covering the articular processes. Treatments for such conditions may include physical therapy, medication, and in some cases, surgery.