| pars intralaminaris nervi optici | <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) |
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| pars intraocularis nervi optici | <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) |
| 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) |
| 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) |
| nucleus tractus mesencephali nervi trigemini | <anatomy, nerve> A long, narrow plate of unipolar neurons extending throughout the length of the midbrain, in and along the lateral angle of the central gray substance. The nucleus is the single known instance of primary sensory neurons enclosed in the central nervous system instead of in a peripheral sensory ganglion. Its peripheral axonal processes pass with the trigeminal nerve, give collaterals to the trigeminal motor nucleus, and terminate in the muscles of mastication. Synonym: nucleus tractus mesencephali nervi trigemini. (05 Mar 2000) |
| nucleus tractus solitarii | A slender cell column extending sagittally through the dorsal part of the medulla oblongata, beneath the floor of the rhomboid fossa, immediately lateral to the limiting sulcus. It is the visceral sensory (visceral afferent) nucleus of the brainstem, receiving the afferent fibres of the vagus, glossopharyngeal, and facial nerves by way of the solitary tract. The caudal two-thirds of the nucleus processes impulses originating in the pharynx, larynx, intestinal and respiratory tracts, and heart and large blood vessels; its rostral one-third receives impulses from the taste buds and is known as the rhombencephalic gustatory nucleus. Synonym: nucleus tractus solitarii. (05 Mar 2000) |
| nucleus tractus spinalis nervi trigemini | The long sensory nucleus extending from the caudal border of the pontine sensory nucleus of the trigeminus down through the lateral region of the rhombencephalon into the upper three segments of the spinal cord's dorsal horn; it receives the fibres of the sensory root of the trigeminal nerve which descend along its lateral border as the spinal tract of trigeminal nerve. Synonym: nucleus tractus spinalis nervi trigemini, descending nucleus of the trigeminus, spinal nucleus of the trigeminus. (05 Mar 2000) |
| tractus | Synonym: tract. Origin: L. A drawing, drawing out, extent, tract, fr. Traho, pp. Tractus, to draw (05 Mar 2000) |
| tractus centralis tegmenti | A large fibre bundle passing longitudinally through the central mesencephalic and pontine tegmentum, distinguished from adjacent longitudinal groups of fibre-fascicles of the reticular formation by a more compact composition. In transverse sections of the mesencephalon the bundle occupies a large triangular area lateral to the medial longitudinal fasciculus; farther caudally it expands ventralward and finally passes over the lateral side of the (inferior) olivary nucleus, becoming part of the latter's fibre capsule. The bundle contains fibres from the mesencephalic tegmentum and regions surrounding the central gray substance descending to the olivary nucleus; it also includes numerous fibres ascending from the medullary, pontine, and mesencephalic reticular formation to the thalamus and subthalamus region. Synonym: tractus tegmentalis centralis, central tegmental fasciculus, tractus centralis tegmenti. (05 Mar 2000) |
| tractus cerebellorubralis | That component of the superior cerebellar peduncle (brachium conjunctivum) which distributes fibres within the red nucleus of the opposite side. Synonym: tractus cerebellorubralis. (05 Mar 2000) |