Do you see the similarities between the character Sid of "Ice Age" and the cross section at C1 level?
The atlantoaxial joint: a cross section at C1 level.
See the beautiful cervical cross section at C1 level, made by Rauschning in 1991. It's remarkably detailed: the spinal cord, the nerves, the vertabral artery, the C2 dens and the transverse atlantoaxial ligament, and all surrounding muscles. Rauschning wrote about this picture the following:
"Axial section of the atlas through the lateral masses and the posterior arch. The mid–portion of the odontoid process displays articular cartilage anteriorly and also posteriorly where it articulates with the transverse ligament. Lateral to the dens loose areolar vascular tissue. The lateral masses are composed of strong cancerous bone whereas the arches contain more cortical bone. The vertebral arteries are about to enter the transverse foramina of the atlas. They are surrounded by a rete of veins which is continuous with the venous sinusoids which surround the nerve roots in the root canals (periradicular venous plexus) and with the wide sinusoids which surround the thecal sac (epidural veins, internal vertebral venous plexus). These venous compartments display black on cadaveric sections because they are filled with cruor mortis. Note that these epidural veins constitute wide vascular compartments with relatively few septa rather than a serpiginous rete of veins. The thecal sac is oval and renders ample space for the spinal cord which clearly displays the anterior median fissure and the posterior median sulcus. A great number of rootlet filaments emerging from the anterolateral and posterolateral sulcus stepwise merge intrathecally to larger dorsal and ventral roots".
Wolfgang Rauschning, M.D., Ph.D.
Professor of Clinical Anatomy
Academic University Hospital
Department of Orthopaedic Surgery
Uppsala, Sweden
(spineuniverse.com)