• The posterior part of the arch presents above and behind a rounded edge for the attachment of the posterior atlantooccipital membrane, while immediately behind each superior articular process is the superior vertebral notch (sulcus arteriae vertebralis). (wikipedia.org)
  • The AF localizes on the vertebral artery (VA) sulcus posterior to the atlas and has incomplete and complete types. (turkishneurosurgery.org.tr)
  • This is a groove that is sometimes converted into a foramen by ossification of the posterior atlantooccipital membrane to create a delicate bony spiculum which arches backward from the posterior end of the superior articular process. (wikipedia.org)
  • it also transmits the suboccipital nerve (first spinal nerve) On the under surface of the posterior arch, behind the inferior articular facets, are two shallow grooves, the inferior vertebral notches. (wikipedia.org)
  • To investigate the co-occurrence of the arcuate foramen (AF) variation of atlas and intracranial vertebral artery (V4) hypoplasia and, therefore, to understand the pathophysiology of Barré-Lièou syndrome (BLS). (turkishneurosurgery.org.tr)
  • In the medial aspect, the lesser wing of the sphenoid forms the anterior clinoid process, an important landmark for the optic nerve and supracavernous internal carotid artery (ICA). (medscape.com)
  • These foramina help in identifying the frontoethmoid suture line, which marks the inferior extent of the anterior cranial fossa. (medscape.com)
  • The frontal bone houses the supraorbital foramina, which, along with the frontal sinuses, form 2 important surgical landmarks during approaches involving the anterior skull base. (medscape.com)