| ROS | reactive oxygen species; review of systems; rod outer segment |
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| ROSP | rod outer segment protein |
| HARH | High Altitude Retinal Hemorrhage |
| IRMA | 1) Intra-Retinal Microvascular Abnormalities 2) Immuno-Radio-Metric Assay... |
| PRP | 1) Progressive Rubella Panencephalitis 2) Platelet Rich Plasma &... |
| rod outer segment | <ophthalmology, physiology> Major photoreceptor cell of vertebrate retina (about 125 million in a human eye). Columnar cells (about 40m long, 1m diameter) having three distinct regions: a region adjacent to and synapsed with, the neural layer of the retina contains the nucleus and other cytoplasmic organelles, below this is the inner segment, rich in mitochondria, that is connected through a thin neck (in which is located a ciliary body) to the outer segment. The outer segment largely consists of a stack of discs membrane infoldings that are incompletely separated in cones) that are continually replenished near the inner segment and that are shed from the distal end and phagocytosed by the pigmented epithelium. The membranes of the discs are rich in rhodopsin, the pigment that absorbs light. (03 Jul 1999) |
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| rod outer segments | The portion of the retinal rod cell between the inner segment and the pigment epithelium layer of the retina. (12 Dec 1998) |
| rod vision | Vision when the eye is dark-adapted. See: dark adaptation, dark-adapted eye. Synonym: night vision, rod vision, scotopia, twilight vision. (05 Mar 2000) |
| withe-rod | <botany> A North American shrub (Viburnum nudum) whose tough osierlike shoots are sometimes used for binding sheaves. Source: Websters Dictionary (01 Mar 1998) |
| harrington rod insertion | <orthopaedics> A procedure that involves fusing together two or more vertebrae in the spine using either bone grafts or metal rods (Harrington rods). This procedure may be used to correct kyphosis or scoliosis. It is also used in those who require spine stabilisation due to vertebral damage from ruptures discs, fractures, osteomyelitis, osteoarthritis or tumour. (27 Sep 1997) |
| enamel rod inclination | The direction of the enamel rods with reference to the outer surface of the enamel of a tooth. (05 Mar 2000) |
| enamel rod sheath | Organic covering of the individual enamel rod. (05 Mar 2000) |
| all-trans-retinal | The orange retinaldehyde resulting from the action of light on the rhodopsin of the retina, which converts the 11-cis-retinal component of the rhodopsin to all-trans-retinal plus opsin. Synonym: trans-retinal, visual yellow. (05 Mar 2000) |
| blood-retinal barrier | Specialised nonfenestrated tightly-joined endothelial cells that form a transport barrier for certain substances between the retinal capillaries and the retinal tissue. (12 Dec 1998) |
| central retinal artery occlusion | <ophthalmology> The sudden blockage of the retinal artery with a blood clot that commonly leads to a painless but irreversible blindness in that eye. (12 Jan 1998) |
| central retinal fovea | A depression in the centre of the macula retinae containing only cones and lacking blood vessels. Synonym: fovea centralis retinae, central pit. (05 Mar 2000) |
| central retinal vein occlusion | <ophthalmology> The sudden blockage of the retinal vein with blood clot that commonly leads to a painless irreversible blindness in that eye. (12 Jan 1998) |
| retinal | 1. <anatomy> Pertaining to the retina. 2. <biochemistry> The aldehyde of retinol, derived by the oxidative enzymatic splitting of absorbed dietary carotene and having vitamin A activity. In the retina, retinal combines with opsins to form visual pigments. One isomer, 11 cis retinal combines with opsin in the rods (scotopsin) to form rhodopsin or visual purple. Another, all trans retinal (trans r.), visual yellow, xanthopsin) results from the bleaching of rhodopsin by light, in which the 11 cis form is converted to the all trans form. Retinal also combines with opsins in the cones (photopsins) to form the three pigments responsible for colour vision. (18 Nov 1997) |
| retinal adaptation | Adjustment to degree of illumination. (05 Mar 2000) |
| retinal anlage tumour | A benign neoplasm of neuroectodermal origin that most often involves the anterior maxilla of infants in the first year of life. It presents clinically as a rapidly growing blue-black lesion producing a destructive radiolucency; histologically, it is characterised by small round undifferentiated tumour cells interspersed with larger polyhedral melanin-producing cells arranged in an alveolar configuration. Synonym: melanoameloblastoma, pigmented ameloblastoma, pigmented epulis, progonoma of jaw, retinal anlage tumour. (05 Mar 2000) |