The EyeBall

Question 1

the retina is compose of…

Answer 1

a retinal pigment epithelium (RPE)

& layers of the neural retina

Question 2

RPE

Answer 2

simple cuboidal epithelium

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

Question 3

inner limiting membrane

Answer 3

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

Question 4

layer of optic nerve fibers

Answer 4

contains central processes of ganglion cells

these converge at optic disk to form optic nerve

Question 5

ganglion cell layer

Answer 5

cell bodies of ganglion cells

Question 6

inner plexiform layer

Answer 6

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

Question 7

inner nuclear layer

Answer 7

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

Question 8

outer plexiform layer

Answer 8

synapses of photoreceptor cells w/ bipolar and horizontal cells

Question 9

outer nuclear layer

Answer 9

cell bodies of photoreceptors (rods and cones)

Question 10

outer limiting membrane

Answer 10

not a membrane

formed by mem junctions (ZA) bet the apical ends of Mueller cells and photoreceptor cells

Question 11

layer of rods and cones

Answer 11

formed by inner segments and outer segments of rods and cones

Question 12

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

Answer 12

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

Question 13

pigment layer - function

Answer 13

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)

Question 14

inner segment (layer of rods and cones)

Answer 14

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

Question 15

outer segment (layer of rods and cones)

Answer 15

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

Question 16

fovea

Answer 16

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

Question 17

optic disc / papilla

Answer 17

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

Question 18

limbus

Answer 18

junction between slcera and cornea

Question 19

cornea (classify epithelium)

Answer 19

stratified squamous

continuous with the sclera

Question 20

bulbar conjunctiva (classify epithelium)

Answer 20

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

Question 21

sclera (classify)

Answer 21

dense irregular connective tissue

vascularized

Question 22

cornea

Answer 22

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

Question 23

layers of the cornea

Answer 23

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

Question 24

Corneal Stroma (classify)

Answer 24

dense regular CT

organized into lamellae

Question 25

Uvea (middle layer)

Answer 25

Iris, Ciliary body, & Choroid

Question 26

Iris - function

Answer 26

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

Question 27

Ciliary body

Answer 27

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

Question 28

Outer layer of Epithelium of Ciliary body

Answer 28

simple columnar

rich in melanin

Question 29

Inner layer of Epithelium of Ciliary body

Answer 29

nonpigmented

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

Question 30

Choroid

Answer 30

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

Question 31

Aqueous humor

Answer 31

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

Question 32

Glaucoma

Answer 32

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

Question 33

lens

Answer 33

adjustable refractive power

1/3 power of eye

Question 34

accomodation to far object

Answer 34

ciliary mm at rest
suspensory ligaments stretched
lens flattened

Question 35

accomodation to close object

Answer 35

ciliary mm contracted
suspensory ligaments relaxed
lens spherical
refraction increased

Question 36

presbyopia

Answer 36

lens loses elasticity

near pt recedes beyond comf reading dist

Question 37

cataract

Answer 37

clouding of lens, due to denaturation nof lens proteins

Question 38

emmetropic eye

Answer 38

normal proportions

clear image focused on retina

Question 39

hyperopic eye

Answer 39

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

Question 40

myopic eye

Answer 40

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