Psychology Wiki

Assessment | Biopsychology | Comparative | Cognitive | Developmental | Language | Individual differences | Personality | Philosophy | Social |
Methods | Statistics | Clinical | Educational | Industrial | Professional items | World psychology |

Biological: Behavioural genetics · Evolutionary psychology · Neuroanatomy · Neurochemistry · Neuroendocrinology · Neuroscience · Psychoneuroimmunology · Physiological Psychology · Psychopharmacology (Index, Outline)

Annulus of Zinn
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 = Annulus of Zinn, 7 = Trochlea, 10 = Superior tarsus, 11 = Sclera, 12 = Optic nerve
Latin annulus tendineus communis
Gray's subject #227 1022
MeSH [1]
Eye orbit anterior.jpg
Anterior view

The annulus of Zinn, also known as the annular tendon or common tendinous ring, is a ring of fibrous tissue surrounding the optic nerve at its entrance at the apex of the orbit. It is the origin for five of the six extraocular muscles. (Some sources only include four.[1])

It can be used to divide the regions of the superior orbital fissure.[2]

The arteries surrounding the optic nerve are sometimes called the "circle of Zinn-Haller" ("CZH").[3] This vascular structure is also sometimes called "circle of Zinn".


Some sources distinguish between these terms more precisely, with the annulus tendineus communis being the parent structure, divided into two parts: [4]

  • a lower, the ligament or tendon of Zinn, which gives origin to the Rectus inferior, part of the Rectus internus, and the lower head of origin of the Rectus lateralis.
  • an upper, which gives origin to the Rectus superior, the rest of the Rectus medialis, and the upper head of the Rectus lateralis. This upper band is sometimes termed the superior tendon of Lockwood.


It is named for Johann Gottfried Zinn.[5][6] It should not be confused with the Zonule of Zinn, though it is named after the same person.


  1. Anatomy Tables - Eye. URL accessed on 2008-03-17.
  2. Shi X, Han H, Zhao J, Zhou C (2007). Microsurgical anatomy of the superior orbital fissure. Clin Anat 20 (4): 362–6.
  3. 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.
  4. eMedicine - Orbit Anatomy : Article by Guy J Petruzzelli. URL accessed on 2008-03-17.
  5. Who Named It synd/3938
  6. J. G. Zinn. Descriptio anatomica oculi humani. Göttingen, B. Abrami Vandenhoeck, 1755.
This page uses Creative Commons Licensed content from Wikipedia (view authors).