Movement between two adjacent vertebrae is facilitated by what structure?

The movement between two adjacent vertebrae is primarily facilitated by the facet joints. These are synovial joints located at the back of the vertebral column, where the superior and inferior articular processes of adjacent vertebrae meet. The facet joints allow for a controlled range of motion, enabling flexion, extension, and rotation of the spine while also providing stability to prevent excessive movement that could lead to injury.

The role of facet joints is crucial because they are designed to bear weight and distribute loads during movement, thereby protecting the spine's integrity. They also provide a surface that can withstand the wear and tear of regular physical activity, which is essential given the mobility and load-bearing demands placed upon the spine.

Intervertebral discs, while important for cushioning and absorbing shock between the vertebrae, primarily serve the purpose of spacing and providing some degree of movement through their compressible structure, rather than facilitating movement in the same way facet joints do. Ligaments support and stabilize the vertebrae but do not directly contribute to the movements between them. Cartilage acts as a protective and cushioning layer but, like ligaments, does not enable movement between vertebrae.