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Flashcards in The EyeBall Deck (40):
1

the retina is compose of...

a retinal pigment epithelium (RPE)
& layers of the neural retina

2

RPE

simple cuboidal epithelium
forms outermost layer of retina and lies just interior to the choroid

3

inner limiting membrane

inner surface of retina next to vitrous humor
the basal lamina of Mueller cells which provide support for all the neural elements of the retina

4

layer of optic nerve fibers

contains central processes of ganglion cells
(these converge at optic disk to form optic nerve)

5

ganglion cell layer

cell bodies of ganglion cells

6

inner plexiform layer

axons of bipolar cells communicate w/ dendrites of ganglion cells & amacrine cells (integrative neurons)

7

inner nuclear layer

nuclei of all retinal cell types;
bipolar cells
amacrine cells
horizontal cells
Meuller cells
(except ganglion cells, rods, and cones)

8

outer plexiform layer

synapses of photoreceptor cells w/ bipolar and horizontal cells

9

outer nuclear layer

cell bodies of photoreceptors (rods and cones)

10

outer limiting membrane

not a membrane
formed by mem junctions (ZA) bet the apical ends of Mueller cells and photoreceptor cells

11

layer of rods and cones

formed by inner segments and outer segments of rods and cones

12

layers of the neural retina (from vitrous humor side down to the RPE)

inner limiting membrane
layer of optic nerve fibers
ganglion cell layer
inner plexiform layer
inner nuclear layer
outer plexiform layer
outer nuclear layer
outer limiting membrane
layer of rods and cones

13

pigment layer - function

1. light absorption (melanin) - catch light not absorbed by the retina and stop it from being reflected preventing blurrying
2. phagocytosis - of oldest photoreceptor outer segment disks
3. blood/retina barrier - supply nutrients to photoreceptors (glucose, retinal, w-3, fatty acids)

14

inner segment (layer of rods and cones)

synthesis of visual pigments
rich in mitochondria
transfers new vis pigment to outer segment where it is incorporated into disk membranes

15

outer segment (layer of rods and cones)

light transduction
hundreds of disk membranes
new disks on bottom, old on top
disk contain visual pigments and mo mechnan for phototransduction

16

fovea

specialized area of the retina
highest photoreceptor density
highest visual acuity
only cone receptors

17

optic disc / papilla

specialize area of the retina
no photoreceptors = blindspot
swelling of disk = intercranial pressure

18

limbus

junction between slcera and cornea

19

cornea (classify epithelium)

stratified squamous
continuous with the sclera

20

bulbar conjunctiva (classify epithelium)

stratified cuboidal to columnar epithelium
contains goblet cells
covers sclera
continuous with the palpebral conjunctiva (covers inside of eyelid)

21

sclera (classify)

dense irregular connective tissue
vascularized

22

cornea

2/3 optic power of eye
avascular
has five layers
pain fibers of CN V -> spinal nuc of V

23

layers of the cornea

Corneal epithelium - non-k strat squamous
Bowman's mem - basement mem
Corneal stroma - dense reg CT (lamellae)
Descement's Mem - basement mem
Corneal Endothelium - simple squamous

24

Corneal Stroma (classify)

dense regular CT
organized into lamellae

25

Uvea (middle layer)

Iris, Ciliary body, & Choroid

26

Iris - function

regulates amt of light - diameter and pigmentation (# of melanocytes)
constrictor pupillae - circumf smooth mm, parasymp
dilator pupillae - radial, myoepithelial cells, sympathetic

27

Ciliary body

an extension of the choroid
secretes aqueous humor
focuses light (by changing lens shape)

28

Outer layer of Epithelium of Ciliary body

simple columnar
rich in melanin

29

Inner layer of Epithelium of Ciliary body

nonpigmented
columnar cells derived from retina, involved in formation of aqueous humor

30

Choroid

located deep to sclera, post ciliary body
provides nutrients
absorbs excess light
pigmented due to melanocytes
choriocapillary lary lies exterior to the RPE and ends anteriorly at the ora serrata

31

Aqueous humor

in ant and post chambers
nutrients for cornea and lens
secreted by ciliary body
reabsorbed by trabecula meshwork that drains via canal of schlemm into venous capillaries of choroid
intraocular pressure mmHg

32

Glaucoma

increase in intraocular pressure
restricts blood flow to retina
(aq humor cant drain)

33

lens

adjustable refractive power
1/3 power of eye

34

accomodation to far object

ciliary mm at rest
suspensory ligaments stretched
lens flattened

35

accomodation to close object

ciliary mm contracted
suspensory ligaments relaxed
lens spherical
refraction increased

36

presbyopia

lens loses elasticity
near pt recedes beyond comf reading dist

37

cataract

clouding of lens, due to denaturation nof lens proteins

38

emmetropic eye

normal proportions
clear image focused on retina

39

hyperopic eye

farsightedness
eye too short and/or lens not strong enough
image focused behind retina
biconvex lens to fix

40

myopic eye

nearsightedness
eye too long and/or lens too strong
image focused infront of retina
biconcave lens to fix