Vision (Slides 1-9, Quiz 3) Flashcards
What is glaucoma?
intraocular pressure is high
What is poor accommodation?
unable to bend light and focus info onto the retina
What is astigmatism?
eyes will change the direction of light over the photo receptors
What is cataracts?
cloudy lens
What are the 3 layers of the eye?
1) outer layer of the eyeball= sclera (the white of the eye)
2) middle layer= choroid
3) inner layer= retina (lines the back two-thirds of the eyeball)
Which part of the eye is pigmented with melanin?
the iris
Which part of the eye is a hole in the iris?
the pupil
Suspensory ligaments are attached to what?
ciliary body and smooth muscle that is innervated by the ANS
What is macular degeneration?
macula slowly degenerates and you wont be able to see with that part of the eye
The receptors (photoreceptors- rods and cones) for vision are located where?
in the retina
Which vitamin is required for rhodopsin (the protein found in photoreceptor disks that bind light)?
vit A
How many different types of neurons are there in the eye?
5 types
Which neurons in the retina send info away from the eye?
ganglion cells
What is the first neuron in the visual pathway?
bipolar cells
How many histo layers are there in the retina?
10 layers (light has to pass through all the layers, as photoreceptors are in the outer layer)
Which layer of the retina houses the nucleus and cell bodies?
nuclear layer
Which layer of the retina has synapses for axons?
plexiform layer
Rods and cones have outer segments fills with discs containing….
test q
rhodopsin
What is the pathway of light?
-light binds to photoreceptors
-this depolarizes and sends AP to bipolar cells
-bipolar cells send APs to ganglion cells
-ganglion cell axons project to the optic disc and out through the optic nerve CN II
T/F: axons are unmyelinated in the retinal layers before the photoreceptors so that light can get through
true, then they are myelinated
What is the blind spot of the eye and does not contain photoreceptors?
optic disc
The _________ is a small depression in the retina of the eye where visual acuity is highest. The center of the field of vision is focused in this region because retinal cones are very concentrated here
fovea
The ___________ is a larger area including and surrounding the fovea. This is the functional center of the retina
macula
Which photoreceptors have a low threshold where very few photons (dim light) can depolarize it?
rods (rods only come with 1 type of rhodopsin whereas cones has several so the AP for rods is either on or off)
Which photoreceptor requires bright light to be activated?
cones
Long wave length of bright light would activate which cone?
red cone
Middle wavelength of bright light would activate which cone?
green cones
Short wavelength of bright light would activate which cone?
blue cone
Which photoreceptor allows us to perceive color vision?
cones
