Posterior atlantooccipital membrane
The posterior atlantooccipital membrane (posterior atlantooccipital ligament) is a broad, thin membrane. It is connected above to the posterior margin of the foramen magnum, and below to the upper border of the posterior arch of the atlas.
Posterior atlantooccipital membrane | |
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![]() Posterior atlantooccipital membrane and atlantoaxial ligament. (Posterior atlantooccipital membrane is topmost gray region at center.) | |
Details | |
Identifiers | |
Latin | membrana atlantooccipitalis posterior |
TA98 | A03.1.08.004 |
TA2 | 1633 |
FMA | 25006 |
Anatomical terminology |
Anatomy
At either lateral extremity of the membrane[1] above the groove for the vertebral artery the membrane forms a gap for the passage of the vertebral artery, and the spinal nerve C1.[1]
The free border of the membrane arches over the artery and nerve, and is sometimes ossified.[1]
Innervation
The membrane is innervated by the spinal nerve C1.[1]
Relations
The membrane is deep to the recti capitis posteriores minores, and obliqui capitis superiores. It is superficial to the dura mater of the vertebral canal to which it is closely associated.
Research
In 2015, Scali et al. revisited the anatomy of the posterior atlantooccipital membrane via plastination. Their findings revealed that the PAO membrane superiorly consisted of periosteum of the occiput, whereas inferiorly it formed part of the dura at the cerebrospinal junction, terminating at the level of the third cervical vertebra (rather than attaching to the posterior arch of the atlas).[2] It is believed that this anatomical arrangement permits a superiorly located anchor point for epidural bridging structures and allows dural tensile forces to act in a summated synchronized manner. The author's hypothesize that this complex area assists with outflow of cerebrospinal fluid.
See also
Additional images
- Median sagittal section through the occipital bone and first three cervical vertebræ.
References
- Sinnatamby, Chummy (2011). Last's Anatomy (12th ed.). p. 426. ISBN 978-0-7295-3752-0.
- Frank Scali; Matthew E Pontell; Lance G Nash; Dennis E Enix (2015). "Investigation of meningomyovertebral structures within the upper cervical epidural space: a sheet plastination study with clinical implications". The Spine Journal. 15 (11): 2417–2424. doi:10.1016/j.spinee.2015.07.438. PMID 26210227.
This article incorporates text in the public domain from page 296 of the 20th edition of Gray's Anatomy (1918)