What ligament prevents the dens of the axis from pressing on the spinal cord during active cervical flexion?

• A. Anterior longitudinal ligament
• B. Transverse ligament
• C. Ligamentum flavum
• D. Interspinous ligament

Answer: (B)

The transverse ligament is crucial in maintaining the stability of the atlantoaxial joint and preventing the dens of the axis from compromising the spinal cord during active cervical flexion. This ligament encircles the dens and attaches to the lateral masses of the atlas (C1), forming a strong arch that holds the dens in place.

As the cervical spine flexes, without the support of the transverse ligament, the dens could potentially move anteriorly and impinge on the spinal cord, leading to serious neurological consequences. The transverse ligament's role is to secure the dens, allowing for safe movement of the head and neck while safeguarding the delicate structures of the spinal cord.

Other ligaments, such as the anterior longitudinal ligament, ligamentum flavum, and interspinous ligament, play different roles within the spinal column, including limiting spinal extension, providing support between vertebrae, and aiding in the stability of the spinal column, but they do not have the specific function of securing the dens during flexion like the transverse ligament does.