Cervical Anatomy and Pathology - Superior Portion of the Atlas

Superior Portion of the Atlas

Axial section through the superior portion of the atlas at the level of the tip of the odontoid process lateral of which the strong alar ligaments insert into notches at the anterior–inferior aspect of the occipital condyles. Richly vascularized areolar fat tissue occupies the angles between the dens and the anterior arch of the atlas. Laterally the vertebral arteries present as they curve posteriorly immediately after having left the transverse foramina of the atlas. A few millimeters cranial to this section the vertebral arteries have pierced the atlanto–occipital membrane into the vertebral canal and are also traversing the thecal sac to become the intrathecal constituents of the basilar artery which forms by merging of these arteries anterior to the medulla oblongata in the midline. Posterior to the round lower medulla oblongata the CSF compartment of the cisterna magna expands. Small intrathecal rootlets are located lateral to the medulla, thicker posterior rootlets are separated from thinner anterior root filaments by the suspensory dentate ligament. Anterior to the atlas lie the longus colli muscle. At their lateral aspect lie the internal carotid arteries posterior to which the vagus nerve and the sympathetic trunk are located.

Updated on: 11/29/18

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