retinal

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retinal

 [ret´ĭ-nal]
1. pertaining to the retina.
2. the aldehyde of retinol, having vitamin A activity. One isomer (11-cis-retinal) combines with opsin in the retinal rods (scotopsin) to form rhodopsin (visual purple); another, all-trans-retinal, or visual yellow, 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 retinal cones to form the three pigments responsible for color vision.

ret·i·nal

(ret'i-năl),
1. Relating to the retina.
2. Retinaldehyde, most commonly referring to the all-trans form; participates in the visual process; 11-cis-retinal binds with an opsin to form iodopsin or rhodopsin; light causes the formation of all-trans-retinal, which dissociates from the protein.

retinal

/ret·i·nal/ (ret´ĭ-n'l)
1. pertaining to the retina.
2. the aldehyde of retinol, derived from absorbed dietary carotenoids or esters of retinol and having vitamin A activity. In the retina, retinal combines with opsins to form visual pigments. The two isomers 11-cis retinal and all-trans retinal are interconverted in the visual cycle.

retinal 1

(rĕt′n-ăl′)
adj.
Of or relating to the retina of the eye.

retinal 2

(rĕt′n-ăl′, -ôl′)
n.
Either of two chromophores that are aldehydes of vitamin A1 and vitamin A2 and that bind covalently with an opsin protein to form rhodopsin or porphyropsin. Also called retinene.

retinal

[ret′inəl, ret′inal′]
Etymology: L, rete
1 n, an aldehyde precursor of vitamin A produced by the enzymatic dehydration of retinol. It is the active form of the vitamin necessary for night, day, and color vision. See also retinene, vitamin A.
2 adj, pertaining to the retina.

retinal

adjective Referring to the retina noun 11-cis-retinal, vitamin A aldehyde A retinal pigment that absorbs visible light at 400-600 nm, resulting in an isomeric transition of the 11-cis-retinal moiety to a trans-retinal conformation causing a G protein-mediated depolarization event

ret·i·nal

(ret'i-năl)
1. Relating to the retina.
2. Retinaldehyde; most commonly referring to the all-trans form.

retinal

The aldehyde found in visual pigments, such as visual purple. Also known as retinaldehyde.

retinal 

1. Pertaining to the retina.
2. See rhodopsin.

retinal

1. pertaining to the retina.
2. the aldehyde of retinol, having vitamin A activity. One isomer(11-cis-retinal) combines with opsin in the retinal rods (scotopsin) to form rhodopsin (visual purple); another, all-trans-retinal, or visual yellow, 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 retinal cones to form the three pigments responsible for color vision.

retinal absence
inherited as a recessive character in foals.
central progressive retinal atrophy
a disease of the retinal pigmented epithelium, generally in middle-aged Labrador retrievers, Border collies, Golden retrievers, Irish setters, and English springer spaniels. There are pigmentary changes in the tapetal fundus, with attenuation of retinal vasculature, and atrophy of the optic disk. Day vision is affected first, followed by impairment, but not always blindness, in any situation. Called also CPRA.
retinal degeneration
see progressive retinal atrophy (below), bright blindness, taurine nutritional deficiency, retinopathy.
retinal detachment
see retinal detachment.
retinal dialysis, retinal disinsertion
separation of the sensory retinal layer from the pigment layer at the ora ciliaris retinae.
retinal dysplasia
a congenital anomaly in many species, consisting of an abnormal differentiation of retinal cells and proliferation of photoreceptors, forming rosettes. May be caused by viral infections such as feline panleukopenia, bluetongue, bovine virus diarrhea and canine herpesvirus; an inherited defect in some breeds of dogs and cattle.
retinal ganglionic cell layer
the layer of the retina which contains ganglion cell bodies.
retinal hemorrhages
occur in association with many systemic diseases and intoxications in most species, including ethylene glycol poisoning, ehrlichiosis, severe anemia and thromboembolic meningoencephalitis in cattle.
inner retinal nuclear layer
the layer of the retina which contains the cell bodies of bipolar neurons and association neurons.
light-induced retinal degeneration
a phototoxic degeneration in rats and mice caused by exposure to continuous light and high temperatures.
retinal nuclear layer
the layer of the retina which includes inner and outer nuclear layers of the retina.
retinal optic nerve fiber layer
retinal layer of axonal processes of the ganglion cells as they approach the optic papilla and emerge as the optic nerve.
outer retinal nuclear layer
the layer of the retina which contains the cell nuclei of the photoreceptor cells.
retinal photoreceptor layer
the retinal layer which contains rods and cones, modified neuronal processes of the photoreceptor rod and cone cells.
retinal pigment epithelial layer
retinal layer just beneath the choroidal basal complex of the eye; probably serves as a store of vitamin A. Long cellular processes extend to and between the photoreceptor cells in the next layer.
retinal plexiform layer
the retinal layer which includes inner and outer plexiform layers; both consist of a network of cell processes of adjacent nerve cells, especially photoreceptor and ganglion cells.
progressive retinal atrophy
a group of inherited, degenerative diseases of the retina, occurring most commonly in dogs and consisting of a progressive, noninflammatory degeneration or dysplasia of rods and cones or purely cones, leading to blindness. Specific features, such as age of onset, pattern of degeneration, and ultrastructural and biochemical changes vary between the many breeds in which the disease is found. Night blindness followed by a loss of day vision are clinical signs common to most. There may also be an associated cataract formation. See also central progressive retinal atrophy (above), cone dysplasia, rod-cone dysplasia. Called also PRA.
progressive retinal degeneration
in one system of classification, a term encompassing a range of retinal disorders otherwise referred to as various types of retinal atrophy, retinal dysplasias or retinal degenerations. The inherited rod-cone dysplasias of dogs and cats are included in Type I; pigment epithelial dystrophy (central progressive atrophy) is Type II; and hemeralopia of Alaskan malamutes and miniature poodles is Type III. Called also PRD.
sudden acquired retinal degeneration
a nonspecific degeneration of rods and cones that progresses to complete retinal atrophy and blindness in mature dogs. The cause is unknown. Called also silent retina syndrome, metabolic toxic retinopathy, SARD.