| cone cell of retina | 1. <plant biology> In gymnosperms and club mosses, a group of sporophylls arranged compactly on a central axis, in the angiosperm family Casuarina, a woody multiple fruit incorporating the bracts and bracteoles associated with the flowers. 2. <physiology> The retinal cone responsible for colour vision. (03 Jul 1999) |
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| plexiform layers of retina | Layer's of the retina where synapses occur; in the external layer, processes of rods and cones synapse with bipolar neuron dendrites; in the internal layer, axon terminals of bipolar cells synapse with ganglion cell dendrites. See: retina. Synonym: stratum plexiforme externum et internum retinae. (05 Mar 2000) |
| primary pigmentary degeneration of retina | A hereditary disorder of the retina mainly affecting photoreceptors and retinal pigment epithelium; a miscellaneous category including Friedreich's ataxia, Refsum's disease, and abetalipoproteinaemia. Synonym: primary pigmentary degeneration of retina. (05 Mar 2000) |
| hole in retina | A break in the continuity of the sensory retina, permitting separation between the retinal pigment epithelium and sensory retina. (05 Mar 2000) |
| horizontal cells of retina | Cell's in the outer part of the inner nuclear layer of the retina that lie with their axes more or less parallel with the surface. They are thought to connect the rods of one part of the retina with cones of another part. (05 Mar 2000) |
| separation of retina | <ophthalmology> A painless disorder (when spontaneous) where the patient complains of a gradual raising or lowering of a curtain over the visual field of the affected eye. May also occur as the result of trauma. (27 Sep 1997) |
| shot-silk retina | The appearance of numerous wavelike, glistening reflexes, like the shimmer of silk, observed sometimes in the retina of a young person. Synonym: shot-silk phenomenon, shot-silk reflex. (05 Mar 2000) |
| nasal venules of retina | See: inferior nasal venule of retina, superior nasal venule of retina. (05 Mar 2000) |
| nervous part of retina | nervous part of retina |
| neural retina | <embryology> Layer of nerve cells in the retina, embryologically part of the brain. The incoming light passes through nerve fibres and intermediary nerve cells of the neural retina, before encountering the light sensitive rods and cones at the interface between neural retina and the pigmented retinal epithelium. (04 Jul 1999) |
| nuclear layers of retina | The outer nuclear layer, layer 4, of the retina, neuroepithelial layer of retina, and the inner layer, layer 6, of the retina, ganglionic layer of retina. Synonym: granular layers of retina, stratum nucleare externum et internum retinae. (05 Mar 2000) |
| superior nasal arteriole of retina | The branch of the central artery of the retina that passes to the upper medial, or nasal, part of the retina. Synonym: arteriola nasalis retinae superior. (05 Mar 2000) |
| superior nasal venule of retina | The small vein that drains blood from the upper medial (nasal) part of the retina; it joins the central vein. Synonym: venula nasalis retinae superior. (05 Mar 2000) |
| superior temporal arteriole of retina | The branch of the central artery of the retina that passes laterally above the macula to supply the upper lateral or temporal part of the retina. Synonym: arteriola temporalis retinae superior. (05 Mar 2000) |
| superior temporal venule of retina | The venule that passes from the upper lateral (temporal) part of the retina to join the central vein. Synonym: venula temporalis retinae superior. (05 Mar 2000) |