| optic nerve | <anatomy, nerve> The optic nerve. The nerve carrying impulses for the sense of sight. Projection from the vertebrate retina to the midbrain. Embryologically, a CNS tract rather than a peripheral nerve. Popular experimental preparation for studies of regeneration of retino tectal projections in lower vertebrates and also for studies of glial cell lineage in CNS. Synonym: cranial nerve II. (18 Nov 1997) |
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| optic nerve diseases | Diseases of the optic nerve. (12 Dec 1998) |
| optic nerve drusen | Basophilic, calcareous, laminated acellular bodies within the optic nerve anterior to the scleral lamina cribrosa. (05 Mar 2000) |
| optic nerve glioma | <radiology> F = M, child / young adult (75% less than 10 yrs, 90% less than 20 yrs), fusiform, isodense mass, with or without enhancement, rarely calcified associated with neurofibromatosis Cf: optic nerve meningioma (12 Dec 1998) |
| optic nerve head | The portion of the optic nerve seen in the fundus with the ophthalmoscope. It is formed by the meeting of all the retinal ganglion cell axons as they enter the optic nerve. Because the retina at the optic disk has no photoreceptors there is a corresponding blind spot in the visual field. (12 Dec 1998) |
| optic nerve hypoplasia | Congenitally small optic disk resulting from failure of development of retinal ganglion cells, with a reduced number of axons; visual impairment may be marked. See: de Morsier's syndrome. (05 Mar 2000) |
| optic nerve meningioma | <radiology> Female (80%), middle age, (24% occur before 10 yrs, but are associated with neurofibromatosis), tubular, hyperdense mass, intense tramtrack enhancement, ** Cf: optic nerve glioma (12 Dec 1998) |
| optic nerve sheath decompression | A venting of the optic nerve sheath into the retrobulbar space, by slitting or by fenestrating the sheath. See: optic nerve sheath fenestration. (05 Mar 2000) |
| optic nerve sheath fenestration | The cutting of a window in the dura of the optic nerve sheath to relieve papilledema and prevent further loss of optic nerve fibres. (05 Mar 2000) |
| ganglionic layer of optic nerve | <anatomy, nerve> The inner layer of multipolar neurons in the retina consisting of the relatively large neurons that give rise to the fibres of the optic nerve. Synonym: stratum ganglionare nervi optici. (05 Mar 2000) |
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| vascular circle of optic nerve | <anatomy, nerve> A network of branches of the short ciliary arteries on the sclera around the point of entrance of the optic nerve. Synonym: circulus vasculosus nervi optici, circulus arteriosus halleri, circulus zinnii, Haller's circle, Zinn's corona, Zinn's vascular circle. (05 Mar 2000) |
| coloboma of optic nerve | <anatomy, nerve> A congenital notch in the formation of the optic nerve, appearing as a craterlike excavation at the optic disk. (05 Mar 2000) |
| postlaminar part of optic nerve | <anatomy, nerve> The portion of the optic nerve posterior to the lamina cribrosa of the sclera. Synonym: pars postlaminaris nervi optici. (05 Mar 2000) |
| prelaminar part of optic nerve | <anatomy, nerve> The portion of the optic nerve anterior to the lamina cribrosa of the sclera. Synonym: pars prelaminaris nervi optici. (05 Mar 2000) |
| drusen of the optic nerve head | Basophilic, laminated, calcareous acellular masses that resemble crystals within the nerve head, anterior to the lamina cribrosa, that may simulate papilledema and/or cause visual field defects. Synonym: intrapapillary drusen. (05 Mar 2000) |
| dural sheath of optic nerve | <anatomy, nerve> The outer sheath around the optic nerve, continuous with the dura mater. Synonym: vagina externa nervi optici, dural sheath of optic nerve. (05 Mar 2000) |
| internal sheath of optic nerve | <anatomy, nerve> The innermost sheath around the optic nerve, continuous with the leptomeninges (pia-arachnoid) and including a cerebrospinal fluid-filled intervaginal space, continuous with the subarachnoid space. Synonym: vagina interna nervi optici. (05 Mar 2000) |
| intersheath spaces of optic nerve | <anatomy, nerve> The spaces within the internal sheath of the optic nerve, between the arachnoidal and pial layers, filled with cerebrospinal fluid and continuous with the subarachnoid space. Synonym: spatia intervaginalia nervi optici, intersheath spaces of optic nerve, Schwalbe's spaces. (05 Mar 2000) |
| intervaginal space of optic nerve | <anatomy, nerve> The spaces within the internal sheath of the optic nerve, between the arachnoidal and pial layers, filled with cerebrospinal fluid and continuous with the subarachnoid space. Synonym: spatia intervaginalia nervi optici, intersheath spaces of optic nerve, Schwalbe's spaces. (05 Mar 2000) |
| intracanicular part of optic nerve | <anatomy, nerve> The part of the optic nerve lying within the optic canal. Synonym: pars intracanaliculus nervi optici. (05 Mar 2000) |
| intracranial part of optic nerve | <anatomy, nerve> The portion of the optic nerve between the optic canal and the optic chiasm. Synonym: pars intracranialis nervi optici. (05 Mar 2000) |
| intralaminar part of optic nerve | <anatomy, nerve> The portion of the optic nerve as it passes through the lamina cribrosa of the sclera. Synonym: pars intralaminaris nervi optici. (05 Mar 2000) |
| intraocular part of optic nerve | <anatomy, nerve> The part of the optic nerve within the eye; it is divided into intralaminar, postlaminar, and prelaminar parts. Synonym: pars intraocularis nervi optici. (05 Mar 2000) |
| orbital part of optic nerve | <anatomy, nerve> The part of the optic nerve between the eye and the optic canal. Synonym: pars orbitalis nervi optici. (05 Mar 2000) |