031 How Rods and Cones respond to Light

http://www.interactive-biology.com - In this episode, I go through the process of how rods and cones respond to light. I use Rods as an example and show how Rhodopsin, Transducin and Phosphodiesterase are involved in the process. Enjoy

Category:

Education

Tags:

• vision
• rods
• cones
• retina
• lens
• receptor potential
• Human eye
• how the eye works
• Nervous system
• senses
• interactive biology

[EphraimHeinrich]

Interesting and well done video. But I miss some details to the reactions happening in the rods. For example the fact that the whole process is a cascade.

[InteractiveBiology]

@EphraimHeinrich Hi, thank you for watching. Leslie will be uploading more videos by next year. He just might or might not tackle this topic again with more clarifications. Please stay tuned for more!

[Ckaotenkind]

Thank you a lot. I'm from Germany and although the videos are in english I understand it very well. You rescued me for my biology test tomorrow. And now I will be able to write it in english :) Unfortunately my teacher won't understand one single word. THANK YOU, it's very well explained

[InteractiveBiology]

@Ckaotenkind Well, we're glad to know you've gained something from it. We hope you aced your test. Stay tuned because we have new Biology videos coming very soon :)

[joinmebowser9000]

@InteractiveBiology Can't wait for that video. I remember this video was why I subscribed. You really saved my day!

[InteractiveBiology]

@joinmebowser9000 THank You! Keep on watching :) We'll have more added to the site very soon!

[AbdullahDiaa2]

@belvidere123 and cGMP is not depolarizing directly => it opens the cGMP gated Na channels => causing depolarization through Na entry to the cell // and in the dark there'll be more more cGMP and less GMP as there's NO light photons which activate PDE and as a result converting cGMP to GMP !!

[AbdullahDiaa2]

@belvidere123 Rod cells have a relatively high concentration of cGMP => the cGMP-gated Na Channels are open => Na enters rods => increase membrane potential in the DARK ,, once photons hit Rhodopsin => PDE will be activated => converting cGMP to GMP => closing the Na channels => decreasing membrane potential

[belvidere123]

If in the dark there, PDE converts CGMP into GMP, how is CGMP depoloarizing?  Wouldnt there be less CGMP and more GMP in the dark.

[mp5yourmp3]

@88rampitup88 and you think thats enough to say "the fovea contains a lot of rods and cones?" no. its very misleading

[88rampitup88]

@mp5yourmp3 You are incorrect. While the central 300 µm of the fovea, called the foveola, is totally rod-free, there are actually some rods scattered amongst the cones in the rest of the fovea.

[dearizqi]

Great video! very simple explained. It helps me to understand my medical study about the eye. Thank youuuu soo much.

[mp5yourmp3]

great video. but at the beginning you said the fovea contains a lot of rods and cones, which i believe is false. it ONLY contains cones.

[xxnaruto1234xx]

@bizz76 Yes, we entirely use cones in bright light since there are very low cGMP levels in rods and no further hyperpolarization can be done. Also, the process is same for cones as well and in response to light, they also go through hyperpolarization. Only difference is cones have different type/s of opsins present.

I think you are confusing cones with the Bipolar cells? I hope InteractiveBiology can cover a topic on Bipolar cells and their receptive field.

[bhatiakaran71]

Very simply explained...

Great video...Thanx...