Retina Structure and Phototransduction Quiz

Extensions of Müller’s cells and astrocytes

Towards the optic disc and then in the optic nerve

Further developments in animal models with migration of retinal cells into the perforated sub-retinal implant

<p>3 types</p> Signup and view all the answers

<p>They mediate the absorption of light by cones</p> Signup and view all the answers

<p>Modulate the response to light</p> Signup and view all the answers

<p>3-5% in the foveal pit, and 15% on the foveal slope</p> Signup and view all the answers

<p>The spectral range of light reaching the retina affects colour perception, and age-related yellowing of the lens can alter this range.</p> Signup and view all the answers

<p>Humans have 3 types of cones, distinguishing colours that differ by 5 nm, while mantis shrimp have 12 types, distinguishing colours that differ by 25 nm.</p> Signup and view all the answers

<p>The relative ratios of different types of cones determine colour sensitivity, with S-cones, M-cones, and L-cones contributing differently to colour perception.</p> Signup and view all the answers

<p>The retina processes signals from cones, while the brain interprets these signals to create our perception of colour.</p> Signup and view all the answers

<p>WebVision, specifically the chapter on retinal circuits.</p> Signup and view all the answers

<p>Light activates Rhodopsin which in turn activates Transducin, leading to the activation of PDE, degradation of cGMP, closure of cGMP-gated channels, and hyperpolarization of the plasma membrane.</p> Signup and view all the answers

<p>Cyclic nucleotides, such as cGMP, play a crucial role in opening or closing ion channels in response to light, ultimately affecting the polarization of the plasma membrane.</p> Signup and view all the answers

<p>Retinal neurons use neurotransmitters such as glutamate and GABA to transmit signals. Glutamate acts as an excitatory neurotransmitter in some pathways and an inhibitory neurotransmitter in others.</p> Signup and view all the answers

<p>Horizontal cells mediate lateral interactions in the outer retina, playing a crucial role in processing visual information and modulating signals between photoreceptors and bipolar cells.</p> Signup and view all the answers

<p>Activation of Rhodopsin triggers a cascade of events involving Transducin and PDE which results in the closure of cGMP-gated channels, decreasing Na+ and Ca2+ influx, leading to hyperpolarization of the membrane.</p> Signup and view all the answers

<p>Gap junctions facilitate direct electrical communication between photoreceptors, bipolar cells, and horizontal cells in the retina, influencing signal integration and synchronization.</p> Signup and view all the answers

<p>Bipolar cells in the retina include rod bipolar cells, S-cone bipolars, midget bipolars, and diffuse bipolars, each with distinct synaptic connections to photoreceptors and ganglion cells.</p> Signup and view all the answers

<p>Bipolar cells receive input from photoreceptors and modulate their responses based on the type of photoreceptor and the conditions of light, either hyperpolarizing or depolarizing in response to specific stimuli.</p> Signup and view all the answers

<p>Cones have a unique structural organization in the phototransduction cascade, with distinct synaptic connections, including pedicles and triads, compared to the spherule and ribbons found in rod phototransduction.</p> Signup and view all the answers

<p>Inhibition of neurotransmitter release, such as glutamate, in photoreceptors plays a crucial role in signal transmission and modulation, contributing to the precision and efficiency of visual processing in the retina.</p> Signup and view all the answers