Biology, asked by PragyaTbia, 1 year ago

Give a brief account of Mechanism of vision.

Answers

Answered by Kinsie
2
Retina is the innermost layer of eye. It contains three layers of cells – inner ganglion cells, middle bipolar cells, and outermost photoreceptor cells. A photoreceptor cell is composed of a protein called opsin and an aldehyde of vitamin A called retinal. When light rays are focused on the retina through cornea, it leads to the dissociation of retinal from opsin protein. This changes the structure of opsin. As the structure of opsin changes, the permeability of membrane changes, generating a potential difference in the cells. This generates an action potential in the ganglionic cells and is transmitted to the visual cortex of the brain via optic nerves. In the cortex region of brain, the impulses are analysed and image is formed on the retina.
Answered by inchudevi459
1

Answer:Mechanism of vision is controlled by the photoreceptor which is present in the rod cell of Retina

Explanation:

vision is one of most important sensesory response of human body.Retina present in the inner portion of eye rhodopsin pigment wich contain photoreceptor that help in our visual perception.Rodopsin is a pigment that consist of opsin and chromophore called 11 cis retinal.When light strikes our eyes at that time the photoreceptor  is activated resuting in the bleaching of rhodopsin to bathorodopsin then to lumirodopsin and last to metarodopsin 1 and metarodopsin 2.

                       The activated photoreceptor inturn helps in the stimulation of phosphodiesterase an enzyme which help in the formation of 5  prime GMP from  cyclic GMP.The lowering of cellular cGMP level causes hyperpolarization by closing sodium ion channel.

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