The Eye

Question 1

What makes up the external layer

Answer 1

sclera and cornea

Question 2

Derivatives of the surface ectoderm

Answer 2

Lens, Corneal epithelium, Conjunctional epithelium

Question 3

what makes up the middle layer of the eye

Answer 3

choroid
ciliary body
iris

Question 4

what makes up the internal layer of the eye

Answer 4

retinal coat, rods and cones

Question 5

virteous body location and content

Answer 5

behind the lens

water (99%), collagen, hyaluronic acid molecules

Question 6

sclera tissue makeup and function

Answer 6

thick layer of DICT
protects, maintains shape
fibrous coat, supportive function, inelastic
opaque white

Question 7

choroid content and function

Answer 7

layer of loose connective tissue
melanocytes – melanized, brown, absorption of stray light
blood vessels, richly vascularized, nutritional

Question 8

Bruch’s membrane ?

Answer 8

layer of extracellular material between the blood vessels and the retinal pigment epithelium.

Question 9

layers of the retina

Answer 9

outer layer of rods and cones
intermediate layer of bipolar neurons
internal layer of ganglion cells

Question 10

horizontal cells of the retina

Answer 10

interconnect photoreceptor cells

Question 11

amacrine cells of the retina

Answer 11

interconnect bipolar and ganglion cells

Question 12

mueller cells

Answer 12

glial cells within the retina

Question 13

retinal pigment epithelium ?

Answer 13

• absorbs light, pigment granules
• prevents back reflection of light striking retina
• sustains metabolism/pigment turnover of photoreceptors

Question 14

what type of junctions are found in the RPE

Answer 14

• forms part of blood-retinal barrier – tight junctions

Question 15

Detached retina?

Answer 15

no junction between RPE and photoreceptor

Question 16

The retina follows an action potential . T/F ?

Answer 16

False graded

Question 17

fovea ?

Answer 17

highest visual acuity
thinnest retinal region
highest packing density
pure cone photoreceptor region

Question 18

macula lutea

Answer 18

• surrounds the fovea, has mostly rods and a yellow pigment

Question 19

yellow pigment in the eye is also known as

Answer 19

lutein

Question 20

Age-related macular degeneration (ARM)

Answer 20

major cause of blindness in the Western Hemisphere. It is caused by loss of photoreceptors in the macula and is correlated with increasing accumulations of material (debris) in Bruch’s membrane.

Question 21

another cause of ARM

Answer 21

decrease in lutein pigment in the macula,

Question 22

Function of pigment in the macula lutea

Answer 22

pigment protects photoreceptors from light and oxidative damage.

Question 23

optic papilla/.disc is also known as

Answer 23

the blind spot

Question 24

where do the axons of the ganglion cells exit the eyeball?

Answer 24

optic disc

Question 25

Parts of the anterior eye

Answer 25

cilary body, iris, cornea, limbus, lens

Question 26

ciliary processes ?

Answer 26

secrete aqueous humor

Question 27

ciliary muscle?

Answer 27

accomadation

Question 28

responsible for separates anterior and posterior chambers

Answer 28

iris

Question 29

what does the stroma of the iris contain

Answer 29

Melanocytes | Constrictor and Dilator muscles

Question 30

cornea ?

Answer 30

transparent , avascular

Question 31

most focusing of light occurs in the ___ from direct light rays converging on ___

Answer 31

cornea and retina

Question 32

3 layers of the cornea

Answer 32

Corneal epithelium, Corneal stroma, and Corneal endothelium

Question 33

___ constantly pump ions (mostly bicarbonate) from the cornea into the anterior chamber.

Answer 33

corneal endothelial cells

Question 34

Water follows osmotically, and this causes the cornea to be kept in ___ state

Answer 34

partially dehydrated

Question 35

what causes coreal transplants

Answer 35

when corneal cells dies they don't turnover but near cells spread over space.. too much damage can cuase holes =swelling and opacity

Question 36

flow of aqueous humor

Answer 36

pos chamber --> pupil-->ant chamber-->trabecular meshwork --> canal of schlemm-->scleral veins

Question 37

why is there no direct opening b/w meshwork and canal of schlemm

Answer 37

fluid is transcytosed to maintain intraocular pressure

Question 38

glaucoma causes

Answer 38

intraocular pressure irregular from blockage of pigment granules in meshwork

Question 39

what causes transparency in the cornea

Answer 39

the close, regular packing of the proteins (crystallins) in the lens fibers and the absence of light scattering organelles.

Question 40

opacity?

Answer 40

lack of transparency

Question 41

presbyopia

Answer 41

loss of ability to focus actively on nearby objects

Question 42

what is another cause of glaucoma ?

Answer 42

long term asprin use .. acetalyation of crytallines= no glycosylation

Question 43

accommodation : close vs distant objects ? 1. ciliary muscle 2. suspensory ligament 3. lens

Answer 43

close : 1. contract,2. relax 3. curved | distant: 1. relax, 2. contracted 3. flat