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Meaning of RETINA

Pronunciation:  'retnu

WordNet Dictionary
[n]  the light-sensitive membrane covering the back wall of the eyeball; it is continuous with the optic nerve

RETINA is a 6 letter word that starts with R.


 See Also: blind spot, cone, cone cell, eye, fovea, fovea centralis, macula, macula lutea, macular area, membrane, neuroepithelium, oculus, optic, optic disc, optic disk, parafovea, peeper, retinal cone, retinal rod, rod, rod cell, tissue layer, visual cell, yellow spot



Webster's 1913 Dictionary
\Ret"i*na\, n. [NL., from L. rete a net. Cf. {Reticule}.]
The delicate membrane by which the back part of the globe of
the eye is lined, and in which the fibers of the optic nerve
terminate. See {Eye}.

Note: The fibers of the optic nerve and the retinal blood
      vessels spread out upon the front surface of the
      retina, while the sensory layer (called Jacob's
      membrane), containing the rods and cones, is on the
      back side, next the choroid coat.

Medical Dictionary
 Definition: Light-sensitive layer of tissue located at the back of the eye that transmits visual images to the brain.
Biology Dictionary
 Definition: The retina is the innermost layer of the eyeball (the outermost layer being the sclera and the cornea, the middle layer is choroid and the ciliary structures). The retina is the place where the image created by the lens of the eye is focused; the information from this image is turned into nerve impulses, which are then sent to the brain via the optic nerve.
 Definition: the layer of cells in the back of the eye that contains two types of cells, rods and cones, that are sensitive to light.