Lexic.us

Definition of Retinal rod

1. Noun. A visual receptor cell that is sensitive to dim light.

Medical Definition of Retinal rod

1. 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)

Lexicographical Neighbors of Retinal Rod

Literary usage of Retinal rod

Below you will find example usage of this term as found in modern and/or classical literature:

1. Journal of Morphology by Wistar Institute of Anatomy and Biology (1892)
"In one case a retinal rod was seen continuous with one of the lenses or lens elements (Fig. 50). Here the short retinal rod expands as ..."

2. The Popular Science Review: A Quarterly Miscellany of Entertaining and (1869)
"The substance of the vertebrate retinal rod has been discovered to be composed of matter having different refractive power, which is so disposed that the ..."

3. The Ocular muscles by Howard Forde Hansell (1912)
"The larger circle represents the limits of space; the smaller one the retina. It is evident then that every retinal rod and cone has its inevitable related ..."

4. A Text Book of Physiology by John Gray McKendrick (1889)
"The diameter of the «nd of a single retinal rod or cone is about -0032 mm., so that the image falling within the smallest visual angle is '0008 mm. larger ..."

5. Encyclopaedia Britannica: A Standard Work of Reference in Art, Literature (1907)
"... nearly the diameter of a single retinal rod or cone. Two objects, therefore, included in a visual angle of less than 60 seconds, appear as one i>oint. ..."

6. Sight: An Exposition of the Principles of Monocular and Binocular Vision by Joseph LeConte (1897)
"A ,a ray from a point d in space passes in a straight line through the nodal point n, and strikes a certain retinal rod d ; that impression is projected by ..."

Other Resources: