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 [edit on Wikidata] 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. 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[edit] 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[edit] 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[edit] 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. Retrieved 15 January 2022. 4. ^ synd/3938 at Who Named It? 5. ^ J. G. Zinn. Descriptio anatomica oculi humani. Göttingen, B. Abrami Vandenhoeck, 1755. * v * t * e Anatomy of the globe of the human eye Fibrous tunic (outer)| | Sclera| * Episcleral layer * Schlemm's canal * Trabecular meshwork | Cornea| * Limbus * layers * Epithelium * Bowman's * Stroma * Dua's layer * Descemet's * Endothelium Uvea/vascular tunic (middle)| | Choroid| * Capillary lamina of choroid * Bruch's membrane * Sattler's layer | Ciliary body| * Ciliary processes * Ciliary muscle * Pars plicata * Pars plana Iris| * Stroma * Pupil * Iris dilator muscle * Iris sphincter muscle Retina (inner)| | Layers| * Inner limiting membrane * Nerve fiber layer * Ganglion cell layer * Inner plexiform layer * Inner nuclear layer * Outer plexiform layer * Outer nuclear layer * External limiting membrane * Layer of rods and cones * Retinal pigment epithelium | Cells| * Photoreceptor cells (Cone cell, Rod cell) → (Horizontal cell) → Bipolar cell → (Amacrine cell) → Retina ganglion cell (Midget cell, Parasol cell, Bistratified cell, Giant retina ganglion cells, Photosensitive ganglion cell) → Diencephalon: P cell, M cell, K cell, Muller glia Other| * Macula * Perifoveal area * Parafoveal area * Fovea * Foveal avascular zone * Foveola * Optic disc * Optic cup * Ora serrata Anatomical regions of the eye| | Anterior segment| * Adnexa (Eyebrow, Eyelid, Conjunctiva, Lacrimal system, Orbit) * Fibrous tunic * Anterior chamber * Aqueous humour * Iris * Posterior chamber * Ciliary body * Lens * Capsule of lens * Zonule of Zinn | Posterior segment| * Vitreous chamber * Vitreous body * Retina * Choroid Other| * Keratocytes * Ocular immune system * Optical coherence tomography * Eye care professional * Eye disease * Refractive error * Accommodation * Physiological Optics * Visual perception Authority control: Scientific databases | * Terminologia Anatomica | *[v]: View this template *[t]: Discuss this template *[e]: Edit this template