| pars orbitalis nervi optici | <anatomy, nerve> The part of the optic nerve between the eye and the optic canal. Synonym: pars orbitalis nervi optici. (05 Mar 2000) |
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| pars postlaminaris nervi optici | <anatomy, nerve> The portion of the optic nerve posterior to the lamina cribrosa of the sclera. Synonym: pars postlaminaris nervi optici. (05 Mar 2000) |
| pars prelaminaris nervi optici | <anatomy, nerve> The portion of the optic nerve anterior to the lamina cribrosa of the sclera. Synonym: pars prelaminaris nervi optici. (05 Mar 2000) |
| circulus vasculosus nervi optici | <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) |
| spatia intervaginalia nervi optici | <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) |
| stratum ganglionare nervi optici | <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) |
| discus nervi optici | 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) |
| radix | Origin: L. Radix, -icis, root. See Radish. 1. <philosophy> A primitive, from which spring other words; a radical; a root; an etymon. 2. <mathematics> A finite expression, from which a series is derived. 3. <botany> The root of a plant. Source: Websters Dictionary (01 Mar 1998) |
| radix anterior | The motor root of a spinal nerve. Synonym: radix anterior, radix motoria, anterior root, motor root, radix ventralis. (05 Mar 2000) |
| radix arcus vertebrae | The constricted portion of the arch on either side extending from the body to the lamina; bound intervertebral foramina superiorly and inferiorly. Synonym: pediculus arcus vertebrae, radix arcus vertebrae. (05 Mar 2000) |
| radix brevis ganglii ciliaris | A branch of the oculomotor nerve supplying parasympathetic preganglionic nerve fibres to the ciliary ganglion. Synonym: radix parasympathica ganglii ciliaris, radix oculomotoria ganglii ciliaris, motor root of ciliary ganglion, oculomotor root of ciliary ganglion, radix brevis ganglii ciliaris, short root of ciliary ganglion. (05 Mar 2000) |
| radix clinica | That portion of a tooth embedded in the investing structures; the portion of a tooth not visible in the oral cavity. Synonym: radix clinica. (05 Mar 2000) |
| radix cochlearis | <anatomy, nerve> One of the components of the vestibulocochlear nerve; it is made up of the central processes of the bipolar neurons which compose the spiral (cochlear) ganglion in the spiral canal of the modiolus of the bony cochlea; the cochlear root enters the cranial cavity by passing in fascicles through the spiral foraminous tract at the bottom of the internal auditory meatus; it enters the brainstem through the pontomedullary groove, closely adhering to the caudoventral aspect of the vestibular root, and distributes its fibres to the ventral and dorsal cochlear nuclei in the floor of the lateral recess of the fourth ventricle. Synonym: radix cochlearis, cochlear root of vestibulocochlear nerve, inferior root of vestibulocochlear nerve, radix inferior nervi vestibulocochlearis. (05 Mar 2000) |
| radix dentis | That part of a tooth below the neck, covered by cementum rather than enamel, and attached by the periodontal ligament to the alveolar bone. Synonym: radix dentis, radix, root. (05 Mar 2000) |
| radix dorsalis | The sensory root of a spinal nerve, having a dorsal root ganglion containing the nerve cell bodies of the fibres conveyed by the root in its distal end. Synonym: radix posterior, radix sensoria, posterior root, radix dorsalis. (05 Mar 2000) |