Eye Histology

Question 1

miosis/mydriasis

Answer 1

small pupil/large pupil

Question 2

layers of the eye

Answer 2

outer- sclera/cornea. sclera maintains shape and is dense regular CT

middle- vascular layer
(choroid; ciliary muscle, iris)

retina- two layers- outer pigmented and inner retina proper (neural- 3 layers)

Question 3

which layer of the eye is continuous w/ the dura?

Answer 3

sclera

Question 4

anterior v posterior v vitreous chambers

Answer 4

anterior- cornea to iris

posterior- iris to lens, zonular fibers and ciliary body

a and p chambers filled w/ aqueous humor

vitreous- posterior to lens. filled with vitreous humor

Question 5

“floaters”

Answer 5

hyaloid artery goes to lens directly from optic nerve, but degenerate early in life

remnants can cause floaters

Question 6

5 parts of the cornea

Answer 6

epithelium- 5/6 cell layers w/ basal stem cells

bowmans memrbane- collagen w/o cells

stroma- collagen w/ cells

descemets membrane- fine collagen, thin

endothelium- simple squamous. contains ion pumps for maintaining opacity

Question 7

cornea vasculature

Answer 7

no blood vessles, only pain fibers

limbus has corneal stem cells

nutrition comes from aqueous humor

inflammation can cause inappropriate vascularization via VEGF

Question 8

choroid

Answer 8

highly pigmented and vascular- supplies retina via diffusion

Question 9

ciliary body

Answer 9

intermediate layer (very little retinal layer). contains ciliary muscle, which contracts to relieve tension on suspensory ligaments, rounding the lens and allowing people to focus close

Question 10

aqueous humor production

Answer 10

comes from retinal layers of ciliary body

cuboidal

Question 11

3 components of the lens

Answer 11

capsule- anterior, refractile, thick basement membrane w/ type 4 collagen

subcapsular- simple cuboidal, only on anterior side

lens fibers- majority of lense. cells that lose their nuclei after accumulating crytallin. fibers at the middle of the lens are the oldest

Question 12

hyper/myopia

Answer 12

hyper- focus behind retina, can only see things at a distance

myopia- focus in front of retina, can only see things close up

Question 13

astigmatism

Answer 13

irregular focus point

Question 14

iris

Answer 14

mostly uveal layer, with posterior retinal lining

posterior epithelial layer creates pigment

myoepthelial layer is dilator pupillae- sympathetics

irregular outer layers w/ fibroblasts and pigment cells

Question 15

sphincter pupillae

Answer 15

circular muscle at the edge of the pupil activated by parasympathetics

Question 16

corneal reflex

Answer 16

corneal epithelium transmits along opthalmic nerve. facial nerve activates oribicularis oculi muscles causing bilateral blinking

Question 17

light reflex

Answer 17

light enterss via optic nerve. activates oculomotor nerve resulting in bilateral constriction

Question 18

how is aqueous humor resorbed?

Answer 18

canal of schlemm, sclerl venous sinus

glauocma- inadequate abrosption

Question 19

retinal detachment

Answer 19

seperation of 2 retinal leyers

Question 20

are rods and cones the deep or superficial retinal layers

Answer 20

deep

Question 21

ora serrta

Answer 21

spot in retina anteriorly where rods and cones disappear

Question 22

pars plana

Answer 22

between ciliary body and ora serrta