Which structure is described as the superior continuation of the PLL?

Which structure is described as the superior continuation of the PLL?

• A. Nuchal ligament
• B. Interspinous ligament
• C. Anterior longitudinal ligament
• D. Tectorial membrane

Answer: (D)

The main idea is that the posterior longitudinal ligament continues upward beyond the spine into the cranial cavity as a different structure. Inside the vertebral canal the PLL runs along the posterior surfaces of the vertebral bodies, helping limit flexion. As it ascends to the craniovertebral junction, it becomes the tectorial membrane, a broad sheet that covers the dens and atlas and attaches to the inner surface of the occipital bone near the foramen magnum, blending with the dura. This makes the tectorial membrane the superior continuation of the PLL, stabilizing the craniovertebral junction from above. The other structures sit in different regions or have different roles: the nuchal ligament is a continuation of the supraspinous ligament in the neck, the interspinous ligaments connect adjacent spinous processes, and the anterior longitudinal ligament runs along the front of the vertebral bodies.

The main idea is that the posterior longitudinal ligament continues upward beyond the spine into the cranial cavity as a different structure. Inside the vertebral canal the PLL runs along the posterior surfaces of the vertebral bodies, helping limit flexion. As it ascends to the craniovertebral junction, it becomes the tectorial membrane, a broad sheet that covers the dens and atlas and attaches to the inner surface of the occipital bone near the foramen magnum, blending with the dura. This makes the tectorial membrane the superior continuation of the PLL, stabilizing the craniovertebral junction from above. The other structures sit in different regions or have different roles: the nuchal ligament is a continuation of the supraspinous ligament in the neck, the interspinous ligaments connect adjacent spinous processes, and the anterior longitudinal ligament runs along the front of the vertebral bodies.