eye histology

Question 1

three layers of eyeball

Answer 1

external to internal -fibrous corneoscleral (cornea + sclera) -uvea (iris, cilliary body, and choroid) -retina

Question 2

what contains smooth muscle that regulates pupil size?

Answer 2

iris

Question 3

what contains smooth muscle that regulates lens shape?

Answer 3

cilliary body

Question 4

purpose of choroid?

Answer 4

has vessels to nourish outer retina

Question 5

between the cornea and iris? between the iris and lens? between the lens and the retina?

Answer 5

-anterior chamber (with aqueous humor) -posterior chamber (with aqueous humor) -vitreous space (with vitreous humor)

Question 6

what is responsible for the refraction of light?

Answer 6

cornea

Question 7

layers of cornea

Answer 7

-corneal epithelium - V1 (ophthalmic) nerve endings, ability to regenerate, and microvilli for tear film -corneal stroma - collagen fibers for transparency, Avascular -corneal endothelium - single cell layer for water regulation of cornea

Question 8

damage to what cornea layer will cause swelling and opacity?

Answer 8

corneal endothelium (deep layer)

Question 9

Question 10

what tissue type is the sclera made of?

continuous with what?

Answer 10

dense irregular CT

CNS dura mater

Question 11

canal of schlemm

Answer 11

at junction of cornea and sclera (limbus), this is a venous channel that drains the aqueous humor

Question 12

2 muscles of the iris

Answer 12

2 smooth muscles, both innervated by autonomic fibers

1- dilator (sympathetic)

2. sphincter pupillae (parasympathetic)

Question 13

sympathetic fibers for the dilator muscle originate in

and the parasym. for the sphinctor pupillae in

Answer 13

the superior cervical ganglion

the ciliary ganglion

Question 14

when ciliary body (muscle) contracts, …

Answer 14

tension in the zonula fibers is decreased

lens curvature can then increase

and eye can focus on near objects

Question 15

what produces aqueous humor?

Answer 15

ciliary epithelium

Question 16

pathway for aqueous humor circulation?

Answer 16

cilliary processes/epithelium –> posterior chamber –> through pupil –> anterior chamber –> canal of schlemm

Question 17

excess aqueous humor…

Answer 17

due to less drainage or overproduction can cause increased ICP –> glaucoma or blindness

Question 18

RPE

Answer 18

retinal pigmented epithelium

• melanin containing cells to absorb light
• component of blood-retinal barrier
• vitamin a to photoreceptors
• phagocytic disposal

Question 19

rods or cones:

which is more numerous in periphery?

in central?

Answer 19

rods

conres are the sole receptor in fovea = high visual acuity

Question 20

area of highest visual acuity?

Answer 20

fovea

Question 21

“blind spot”

Answer 21

the optic disc

–point where there are no photoreceptors

-central artery of retina enteres here and where ganglion axons leave

Question 22

lens:

capsule, epithelium, and fibers

Answer 22

c - thick BM

e - simple cubiodal anterior layer

f - elongated epithelium cells with NO nuclei and filled w crystallin protein

Question 23

where are crystallins?

Answer 23

inside lens fibers

Question 24

cataract

Answer 24

clouding of the lens

Question 25

presbyopia

Answer 25

loss of lens elasticity = loss of accomodation for near vision

-occurs w age

Question 26

bulbar vs palpebral conjunctiva

Answer 26

bulbar covers anterior sclera

palpebral lines eyelids

Question 27

muscle that closes eyelids

innervation?

Answer 27

orbicularis oculi

facial VII

Question 28

meibomian glands

Answer 28

eyelid sebacious glands

-help retain film of tears

“tarsal glands”

Question 29

styes

Answer 29

staph infection of eyelid glands

Question 30

chalazion

Answer 30

noninfectious

chronic inflammation of the meibomian glands

Question 31

pink eye

Answer 31

inflammation of the conjunctiva

-conjunctivitis