147 & 148 Visual system I and II Flashcards
where does the optic nerve terminate
lateral geniculate nuclei of the thalamus
what does the fibrous layer consist of
sclera and cornea
what is the purpose of the middle (vascular) layer
focusing and regualting the intensity of light
what does the cilliary body produce
aqueous humor
contraction of the cilliary muscles result in
decreased tension on suspensory ligament, allows lens to increase in thickness, focusing light rays on near object
constrictor muscle is under the influence of
parasympathetics
dilarot muscle is under the influence of
sympathetic control
what does light pass through
cornea, aqueous humor, lens vitreous body
what is the main refractive structure of the eye
cornea
when aqueous humor is drained it goes through
trabecular meshwork and into the sinus venosus sclerae
what happens when aquous humor fails to drain
increases intraocular pressure, leads to glaucoma
what does the term presbyopia mean
failure of the lens to accomadate, happens with age
what is opacification of the lens called
cataract
what is the condition when debris from photoreceptor cells accumulate between the photoreceptor cell layer and the pigment epithelial layer
retinitis pigmentosa
rods are sensitive to
light
cons are responsible for
color
what is more pedominate in the peripheral zone
rods
the fovea only consist of
cones
what is the first order neuron of rods and cones? second order neuron
bipolar cell, ganglion cell
which cells modulate transmission between photoreceptor and bipolar cells
horizontal
what cells modulate transmission between bipolar and ganglion cells
amacrine
what is the area for acute vision
fovea
what happens to rhodopsin when absorbing light and where is it found
in rods, rhodopsin is broken down into retinal and opsin, dependent on vitamin A
where is iodopsin
cones
