Transverse ligament of atlas former is attached to the basilar part of the occipital bone, in close relation with the membrana tectoria; the latter is fixed to the posterior surface of the body of the axis; hence, the whole ligament is named the cruciate ligament of the atlas. The transverse ligament divides the ring of the atlas into two unequal parts: of these, the posterior and larger serves for the transmission of the medulla spinalis and its membranes and the accessory nerves; the anterior and smaller contains the odontoid process. The neck of the odontoid process is constricted where it is embraced posteriorly by
Cervical vertebrae plexus. The cervical spinal nerves emerge from above the cervical vertebrae. For example, the cervical spinal nerve 3 (C3) passes above C3. The atlas (C1) and axis (C2) are the two topmost vertebrae. The atlas, C1, is the topmost vertebra, and along with the axis; forms the joint connecting the skull and spine. Its chief peculiarity is that it has no body because the body of the atlas has been fused with that of the axis. The axis, C2, forms the pivot on which the atlas rotates. The most distinctive characteristic of this bone is the strong odontoid process (dens)