Retina and vision Flashcards
what are the 4 things need dot be able toes an object
1- pattern of object must fall onto vision receptors
2- amount of light entering eye must be regulated
3- energy from photon waves must be transducer into electrical signals
4- brain must receive and interpret signals
what are the 4 main regions of the photoreceptors
outer segment, inner segment, cell body and synaptical terminal
what happens to photoreceptors when light hits the receptors
The Vm hyperpolarises
what does the dark current describe
a cGMP gated Na channel that is open in the dark and closed in the light - resulting in brain perceiving objects in visual field
where are rods present
int he outer segment of photoreceptors
what does the dark current channel do in the lgih
IT CLOSES FOR GODS SAKE
what os the dark channel opened by
cGMP
is there more or less glutamate in the dark
more
what is acuity
ability to distinguish 2 nearby points
what is visual acuity determined by
photoreceptor spacing and refractive power
rods or cones, which one helps you see in dim light
rods
is there more or less convergence in rod system
more
what is the magnetic spectrum that we can see
visible light- 750-350nm
can cones or rods help you see colour
cones
are rods in peripheral or central retina
peripheral
