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 | |
| Latin | anulus tendineus communis |
| TA98 | A15.2.07.015 |
| TA2 | 2047 |
| FMA | 49071 |
| 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):
- Superior division of the oculomotor nerve (CNIII)
- Nasociliary nerve (branch of ophthalmic nerve)
- Inferior division of the oculomotor nerve (CNIII)
- Abducens nerve (CNVI)
- Optic nerve
Parts
editThe 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
editIt 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
edit- ^ 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.
- ^ 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.
- ^ 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.
- ^ synd/3938 at Who Named It?
- ^ J. G. Zinn. Descriptio anatomica oculi humani. Göttingen, B. Abrami Vandenhoeck, 1755.