The common tendinous ring, also known as the annulus of Zinn or annular tendon, is a ring of fibrous tissue surrounding the optic nerve at its entrance at the apex of the orbit. It is the common origin of the four recti muscles of the group of extraocular muscles.

Common tendinous ring
Rectus muscles:
2 = superior, 3 = inferior, 4 = medial, 5 = lateral
Oblique muscles: 6 = superior, 8 = inferior
Other muscle: 9 = levator palpebrae superioris
Other structures: 1 = Common tendinous ring, 7 = Trochlea, 10 = Superior tarsus, 11 = Sclera, 12 = Optic nerve
Anterior view
Details
Identifiers
Latinanulus tendineus communis
TA98A15.2.07.015
TA22047
FMA49071
Anatomical terminology

It can be used to divide the regions of the superior orbital fissure.[1]

The arteries surrounding the optic nerve form a vascular structure known as the circle of Zinn-Haller, or sometimes as the circle of Zinn.[2]

The following structures pass through the tendinous ring (superior to inferior):

Parts

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The common tendinous ring spans the superior orbital fissure and can be described as having two parts – an inferior tendon which gives origin to the inferior rectus muscle, and to part of the lateral rectus muscle; and a superior tendon which gives origin to the superior rectus muscle, and to part of the medial and lateral recti muscles.[3]

Eponym

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It is named for Johann Gottfried Zinn.[4][5] It should not be confused with the zonule of Zinn, though it is named after the same person.

References

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  1. ^ Shi X, Han H, Zhao J, Zhou C (2007). "Microsurgical anatomy of the superior orbital fissure". Clin Anat. 20 (4): 362–6. doi:10.1002/ca.20391. PMID 17080461. S2CID 43849585.
  2. ^ Ko MK, Kim DS, Ahn YK (1999). "Morphological variations of the peripapillary circle of Zinn-Haller by flat section". Br J Ophthalmol. 83 (7): 862–6. doi:10.1136/bjo.83.7.862. PMC 1723100. PMID 10381675.
  3. ^ Shumway, Caleb L.; Motlagh, Mahsaw; Wade, Matthew (2022). "Anatomy, Head and Neck, Eye Inferior Rectus Muscle". StatPearls. StatPearls Publishing. PMID 30085520. Retrieved 15 January 2022.
  4. ^ synd/3938 at Who Named It?
  5. ^ J. G. Zinn. Descriptio anatomica oculi humani. Göttingen, B. Abrami Vandenhoeck, 1755.