Vision Flashcards
(29 cards)
What type of muscles are the extraocular muscles and where do they attach
Rectus, sclera
Name all the structures the light passes through
cornea, pupil, lens, rertina (fovea centralis)
In macula degeneration is the blindness in the centre or periphery
centre
what is the name of the membrane covering the sclera
conjuctiva
when the cilliary muscles contract, what shape is the lends
fatter
what is the function of the choroid
carries blood vessels, maintains photoreceptors
also theh are highly pigmented and contain melain
which structure sperates the a and p chambers
iris!
what supplies blood to the inner two thirds of the retina
central artery and vein
what supplies blood to the outer third of the retina
choroid
what supplies nutrients to the ganlion cells
vitreous humour
what produces aqueuos humor and where does it drain out
Produced by cilliary body, drained out bu schlemms canal
does the aquous humor enter the a or p chamber first
posterior
which nerve innervates the intraocular rectus muscles
3
where are the lacrimal glands located and what cranial nerve innervates them
top lateral corner, cn 7
which cn does somatic senory and which one does special sensory
somatic = 5, special = 2
name the structure that supports the outer retina
pigment epithelium
- contains melalin (therefore dark)
- absrobs light and precents scattering of light, maintains photoreceptos metabolically
at which point does light become an electical signal, at which point does it become an AP
electical at photorecptors, AP at ganglion cells
which nucleus in the midbrain does visual reflexes
superior colliculus
which nucleus in that thalamus is involved in vision
lateral geniculate nucleus
how is power measured
1/focal length
what is the term for when the lens is too strong - and what does it cause
myopia - short signeedness
far point
explain hyperopia
lens too weak, longsightedbess
near point
what is the term for when the cornea has different focusing powers in its planes
astigmatism
more commonly thicker from side view
what type of lens correcrs astogmatism
cylindrical
