Eye Flashcards
Comeoscleral coat
gives eyeball it’s structure and helps refract incoming light rays
Uvea - vascular layer
blood supply is coming form ophthalmic a
includes iris, ciliary ody and choroid
retina
innermost layer/neurolayer of eyeball
visual layer
thick portion located in back of beyeball.
nonvisual part
think portion locatedin anterior part of retina
ora serrata
rough edge where visual retina becomes nonvisual retina
Aqueous humor
fluid-filled environment located in both anterior and posterior channels. No blood vessels here so light rays can pass through.
Vitreous humor
jelly-like
made mostly of water, but has collagen to make it gelatinous
born with this
slow transfer of nutrition from choroid layer
Detached retina
retina is pulled from its blood supply
Cornea
transparent and avascular
provides for 2/3rd of the refractive power
5 layers of corneoscleral coat (from outside to in)
- Corneal epithelium
- Bowman’s membrane
- Corneal stroma
- Descemet’s membrane
- Corneal endothelium
Cornea epithelium
Cells are stratified squamous nonkeratinized
contains ferritin to prevent UV damage
has microvilli on apical surface to help retain lacrimal tears, keeps cornea from drying
innervated by V1
has good mitotic activity
Bowman’s membrane
Anterior basement membrane acellular does not regenerate contributes to strength of cornea barrier to infection
Corneal stroma
heavily packed with different collagenfibrils in different patterns
thickest part of cornea
adjacent lamellae are arranged at right angles to each other which maintains transparancy of cornea
Descemet’s memrane
posterior basement membrane
regenerates after injury
thickens with age
helps miantain normal curbature of cornea
Corneal endothelium
simple squamous epithelium with lots of zonula occludens (tight junction) which allow it to get nutrients and water
limited proliferative ability
responsble for virtually all of metabolic exchanges of cornea
Sclera
white of eyeball
tough fibrous connective tissue, collagen, and elastic fibers to maintain shape of eyeball
3 layers of sclera
tenon’s space, substantia propria, suprchoroid lamina
Tenon’s space
space between periorbital fat and tenon’s capsule
provides eyeball with space to move around in
Substantia propria (tenon’s capsule)
where extraocular eye muscles attach
Suprachoroid lamina
attach is to choroid
how sclera gets nutrients
Are anterior and posterior pigment epithelium separate
yes, separated by basement membrane
What gives color to eyes
anterior and posterior pigment epithelium
What does color of iris depend on
amount of melanocytes
ciliary processes
produce aqueous humor.
no blood cells here
What is the blood-aqueous barrier due to
zona occludens
Flow of aqueous humor
posterior chamber to pupil to anterior chamber to trabecular meshwork to canal of schlemm to venous system
Open-Angle Glaucoma
vision is damaged gradually, may take place over the course of some years. Aqueous humor does not go inot canal of schlemm, causes fluid backup
headaches, burning sensetation in eyes, blurred vision, halos
Closed-Angle Glaucoma
blurry vision, rainbow halos, headaches or severe pain
less common and can cause blindness quickly
circular ciliary muscle
reduces tension on the lens
longitudinal ciliary muscle
strectchs choroid
Choroid
dark-brown layer
lots of melanocytes in vascular region
lies between sclera and retina
5 layers of bruch’s membrane
basal lamina of endothelial cells of choriocapillary layer
collagen fibers
elastic fibers
collagen fibers
basal lamina of the retinal epithelial cells
Neural retina (innermost layer)
has non-photosenstive region and photosenstive region
Non-photosenstive region
anterior to ora serrata
lines the inner part of the ciliary body and posterior surface of the iris
Photosenstive region
posterior to ora serrata
most of retina is visual portion
Optic Disc
where the optic nerve is taking all the information from the retina out and back to brain
no photoreceptor cells here -blindspot
Fovea centralis
site on retina for greatest point of visual acuity
where retina really thins out
Macula lutea
yellow spot
surrounds fovea centralis
