Histology of the Eye

Question 1

Eye 3 layers Outer to Inner

Answer 1

Tunica Fibrosa (sclera, cornea)

Uvea (choroid {vascular}, ciliary body, Iris)

Retina (neural, non-neural)

Question 2

When light hits the eye, whats the order it goes thru

Answer 2

• Cornea
• Anterior Chamber
• Posterior Chamber (behind the eye)
• Vitrious Chamber
• ***KNOW STRUCTURE OF EYE

Question 3

Insects/ Arthropods have what kind of eyes?

Answer 3

Compound Eye- can see motion and shading but can’t focus

Question 4

Tunica Fibrosa structures

Answer 4

Sclera: connective tissue that holds the eye in shape

Cornea: is composed of 5 layers— Corneal Epithelium (more outward touching air), Bowman’s Membrane (extracellular material), Stroma (thrickest layer), Descemet’s Membrane, Endothelium (close to anterior chamber)

Question 5

Canal of Schlemm (at junction of sclera and cornea

Answer 5

Facilitates equilibrium of pressure in the eye by allowing fluid (when theres too much) from anterior chamber flow out through this canal

Question 6

Uvea consists of these 3 layers

Answer 6

1. Choroid: layer of vascular connective tissue (blood vessels) and once it reaches the opening of eye, it forms the iris
2. Ciliary Body:
3. Iris:

Question 7

What is the choriocapillary?

Answer 7

Layer of smaller blood vessels (sub component of Choroid)

Question 8

Ciliary Body

Answer 8

Small structure containing muscle that can contract and change shape of lens for light accommodation

Question 9

Ciliary Body Component

Answer 9

• Ciliary Muscle
• Ciliary Process: folds of epithelium attached to ciliary muscles- each process has zonulary fibers attached to the lens.
• Change of muscle changes the lens size

Question 10

Ciliary Process layers

Answer 10

Double layer of low columnar epithelium.
One pigmented (inner layer because of melanin granules) the other non-pigmented epithelium (outer layer)

Question 11

Ciliary process continues and lines the back of (posterior) what structure…

Answer 11

the Iris

Question 12

Layers of the Iris

Answer 12

Double layer of epithelium

Question 13

What gives rise to eye color>

Answer 13

Double layer of epithelium in the back of Iris- the amount of pigment (melanin granules) in the pigmented epithelium

• Less pigment (blue)
• Intermediate Pigment (green)
• More pigment (brown)
• No pigment (Albino)- looks pink due to reflection of blood

Question 14

Heterochromia Irdis

Answer 14

Difference in coloration can be complete herterochromia

-Part of one iris is a different color from its remainder and finally in central heterochromia there are spikes of different colors radiating from the pupil

Question 15

Zonula Fibers

Answer 15

Oxytalin fibers (first component of elastic fibers) form a bridge between ciliary body processes and the lens

Question 16

Retina Components

Answer 16

lines back of eyeball

1. Neural
2. Anterior Non-Neural: consists of double layer of cells with pigmented and non pigmented epithelia

Question 17

Vitrious chamber

Answer 17

Largest chamber,

has a lot of polyromic acid in it (glycosalidic glycans whichcontain sugars that are hydrophobic)- hold water- viscous

Question 18

Ora Serrata

Answer 18

Transition spot from neural retina (has a spot called the fovea which contains only cones) to non-neural retina (which is double layer of cells that line the ciliated body/process and the back of the iris)

-End of Photoreceptors continues as double layer of epithelium

Question 19

Which part of the eye gives best visual accuity (sharpness)

Answer 19

Fovea

Question 20

3 layers of Neural Retina

Answer 20

1. Outer layer of rods and cones embedded in pigmented epithelium (receive photons of energy in form of light and can initiate stimulus)
2. Intermediate layer of bipolar neurons- Support cells that forms connections with ganglion cells (one end connects with ganglion cell the other connected to rods/cones—one end conencted to bipollar neurons and the other to axons of cells??)
3. Internal layer of ganglion cells- deepest layer

Question 21

Where are rods and cones embedded?

Answer 21

Deepest layer of retina (pigmented epithelium) are the photoreceptors

Question 22

What is most sensitive to light?

Answer 22

Rod Cells- only give black and shades of gray / white- NO COLOR- Rhodospin

Question 23

What is Rhodopsin responisble for?

Answer 23

Shades of black and white

Question 24

Color- variants of iodopin which gives perspection of color

Answer 24

Cone Cells

Question 25

Other name for Fovea Centralis

Answer 25

Macula– area only has CONES NO Rods

Question 26

Macula Degeneration

Answer 26

Lose central part of vision

Question 27

Detached Retina

Answer 27

Condition in which the retina detaches from the choroid-disrupting vision

Question 28

Central Artery of the Retina runs through…

Answer 28

The optic nerve

Question 29

Optic Nerve

Answer 29

Blind Spot also showing the central artery- no rods or cones

Question 30

What is the Non- Neural Retina lined by

Answer 30

Double layer of epithelium lines the ciliary body and posterior iris

Question 31

Accessory Structures of the Eye

Answer 31

Lens, Eyelid & Conjuctiva, Lacrimal Apparatus

Question 32

Lens Components

Answer 32

1. Lens Capsule, proteoglycans, Type IV Collagen
2. Lens Epithelium, simple suboidal to columnar
3. Differentiating lens fibers contain crystallin proteins
4. Mature Lens Fibers

Question 33

Cateract- what is it and what the solution

Answer 33

Clouding of lens, TReated with surgey by removing the natural lens and replaceming with an intraocular lens implant

Question 34

Eyelid Component (inner to outer)

Answer 34

• Conjunctiva (most inner)
• Tarsus Fibroelastic Plate
• Meibomian Gland (sebaceous)
• Orbicular Muscle
• Eyelashes (outer)

Question 35

Conjuctiva Structure

Answer 35

Mucosa covering portion of Sclera continues as lining of internal eyelid, stratified columnar to stratifies squamous

Question 36

Lacrimal Apparatus Produce…

Answer 36

Tears, they are tubuloalveoli acini, serous

Question 37

Extramuscular Muscles

Answer 37

pull muscle to move around and focus