eye anatomy & physio Flashcards
one of the only muscles of the eye with sympathetic innervation
muller’s muscle
what is muller’s muscle innervated by?
CN 3
which CN shuts the eye
CN 7
which CN keeps the eye open
CN 3
what makes the aqueous portion of the tears?
lacrimal gland
2 living layers of the eye
1, epithelium
2. endothelium
____ supplies blood to outer 2/3 of retina, and _____supplies blood to the inner 1/3 of retina
choroid; opthalmic artery
reduced or absent vision
scotoma
loss of half of visual field
hemianopia
loss of either right or left visual field
homoymous
lesion anterior to chiasm
ipsilateral monoocular loss
chiasmal lesion
bitemporal hemianopia
lesion posterior to chiasm
homonymous hemianopia
what is lens metabolism directed towrads?
maintenence of transparency
what is the main location of lens metabolism?
lens epithelium
where does glu enter the lens from/
the aqueous
when is the sorbitol pathway used?
normally only 5%, but when hyperglycemia, it is upregulated
can sorbitol diffuse out of lens?
no, it accumulates and creates an osmotic gradient for influx of H2O–>lens edema
if a person has a sudden change in refractive index?
then consider diabetes
tx for removing sorbitol from eye?
will be converted to fructose, and normalize over 4-6 weeks
what is the refractive surface of the eye?
cornea + lens
what represents 2/3 of the refractive power?
cornea
when refractive power of cornea/lens is different in 1 meridian than in another
astigmatism
hyperopia
farsighted
myopia
nearsighted
decreased ability to focus at near with age
presbyopia
can presbyopia be fixed?
no, cannot be halted with refractive surgery
