Sagittal view of the head at the level of foramen magnum. The foramen magnum is the largest foramen of the skull and marks the junction of the medulla with the spinal cord. The meningeal layer of cranial dura continues into the vertebral canal as the spinal dura. Posterior to the medulla is the tonsil of the cerebellum. Anterior to the medulla is the basilar part of the occipital bone or the clivus. Just inferior to the foramen magnum are the atlas and axis vertebrae. The atlas (C1 vertebra) is a ring of bone with anterior and posterior arches. It lack a body. This is assumed by the upward projecting dens from the body of the axis. The first cervical intervertebral disc occurs between the bodies of the axis and the third cervical vertebra. Anterior to this junctional area is the nasopharynx and oropharynx and the midline soft palate and uvula. Above and lateral to the soft palate are exposed the two principal muscles of the soft palate, namely, the levator veli palatini and tensor veli palatini. (Image courtesy of PA Rubino)