The Visual System Flashcards
What is the purpose of the pupil?
The part of the eye that allows light through. Iris and sclera don’t let light in!
Pupils modulates quantity of light and depth of field.
Why are the cornea and lens curved?
To refract(bend) the light coming in, so that the light is focused on the back of the eye where the photoreceptors are(Retina)
What is the big chamber in the eye called? Why is it called that?
Vitreous chamber, because the chamber is comprised of gelatinous substance called Vitreous.
Define cataract
Term for when lens becomes opaque.
General reasons for this happening is chronic UV exposure.
Define what the back of the eye with very dense photoreceptor concentration is called.
The Fovea.
Why are there no blood vessels in the middle of the eye? Why are they all pushed to the side?
Theory: Moving the blood vessels away from the Fovea prevent light scattering as the light comes through the eye.
What is the scientific name for the blind spot? Why do we have one?
Optic Disk: region, where optic nerve and blood vessels, leave the eye. No photoreceptors on that part of the eye.
After light enters the eye through the cornea how is light modified?
-Pupil modulates quantity of light and depth of field.
-focused on retina by changes in the lens.
After light enters the eye through the cornea and modified through the pupil what happens when light hits the retina?
Photoreceptors transduce light energy into electrical signal.
Explain the neural pathway for producing visual images.
Signal goes to neurons which go to optic disk.
Optic disk: is location where neurons joined the optic nerve.
Optic nerve crosses over in the optic chiasm.
Neurons synapse and lateral geniculate body in thalamus.
Optic tract ends at the visual cortex in the occipital lobe.
Define Pupillary reflex. What does it mean that’s it’s a consensual reflex?
Pupillary reflex is how our eyes dilate to focus our vision. It’s consensual because if it happens to one eye it happens to both eyes!
Describe the pathway for the Pupillary reflex.
Hint: 3 Optic -, two anatomy terms.
What is the problem that causes people to be dyslexic?
Difficulty distinguishing left and right reversal from the visual input you were receiving.
Define optics.
Describes the light behavior and properties.
Define Myopia
Focal point falls in front of the retina.
Define Hyperopia.
Focal point falls behind the retina.
Explain how the ciliary muscle controls the lens in order to change focus.
Why do we say the visual system is backwards?
The light comes through the eye, and before it reaches the photoreceptors it has to travel through all these neurons.
Defined the similarities and differences between rods and cones.
Rods: function well in low light and are used in night vision; Visual pigment-contain rhodopsin
Cones: responsible for high acuity vision, and color vision during the daytime.
Both have some structure: outer, inner, and basal segment; Visual pigment-3 pigments primarily excited by red, green, and blue light.
Visual pigments: convert light energy into a change in membrane potential.
Explain phototranduction in rods. Hint: 3 main steps.
CB is visual FC of this
CB
Define Binocular vision.
The central portion of the visual field, where the visual field of each eye overlap.
Processed to give 3D vision.
Summary test
