Eye Histology

Question 1

What are the three main layers of the eye?

Answer 1

Outer - Fibrous tunic

Middle (vascular)- Uveal

Retinal -

• outer pigmented
• inner retina proper

Question 2

What are the chambers of the eye?

Answer 2

ANTERIOR: cornea to iris

POSTERIOR: iris to lens

VITREOUS SPACE: lens to posterior

Question 3

Tell me some cool facts about Vitreous

Answer 3

Largest chamber, sits in back of eye

-humor present from birth and not renewed,

Has remnants of hyaloid artery that degenerated, FLOATERS

Question 4

What’s the SCLERA?

Answer 4

Dense, regular collagenous connective tissue

Provides shape of eye

Few blood vessels

Question 5

What are the layers of the CORNEA?

Answer 5

Part of the outer layer

1. Epithelium
   - basal cells undergoing mitosis
2. Bowman’s membrane
   - Thin collagen - no cells
   - strength
3. Stroma
   - organized collagen - cellular
4. Descemet’s membrane
   - fine collagen
5. Endothelium
   - simple squamous
   - metabolically active

Question 6

What can you tell me about the general CORNEA?`

Answer 6

Avascular

Pain nerve fibers

Damage epi ok
Damage Bowman = permanent

STRONGEST REFRACTING LAYER

Question 7

CHOROID FACTS

Answer 7

Part of UVEAL (middle) layer (vascular tunic)

HIGHLY vascularized

Nourish outer retina (by diffusion)

PIGMENTED

Question 8

What is the ciliary body?

Answer 8

part of Uveal layer,

Anterior eye

Has ciliary muscle

Question 9

How does the eye focus on near objects?

Answer 9

Ciliary muscles contract

Decrease distance between them and lens

Ligaments attached to lens go slack

Lens go to it’s natural round shape

That focuses on near things

Controlled by PARASYMPATHETICS

Question 10

Where is aqueous humor made?

Answer 10

Cuboidal cells from retinal derived epithelium

Sitting on ciliary body

Question 11

What are the three components of the lens?

Answer 11

avascular

1. CAPSULE:
   - refractive
   - Type IV collagen
2. SUBSCAPULAR EPI:
3. LENS FIBERS
   - flat cells
   - contain CRYSTALLIN

Question 12

Nearsighted

Answer 12

Myopia

See close up

Focus in front of retina

Question 13

Farsighted

Answer 13

Hyperopia

Focus behind the retina

See things at a distance

Question 14

Is the iris just there to be pretty?

Answer 14

Yes and No

Irregular outer layer, pigmented cells

Layer of CT

Vascular layer

Muscle

Question 15

Muscles of the Iris

Answer 15

Dilator papillae muscles

• radiating smooth muscle
• sympathetics

Constrictor/sphincter papillae
-para

Question 16

What are the two eye reflexes?

Answer 16

Corneal

• through ophthalmic (V1)
• back facial nerve

Light

• through optic nerve
• back para of occulomotor