Exam 2: Eye

Question 1

Layers of Eye

Answer 1

Fibrous layer (Corneoscleral coat), Vascular Coat (Uvea), Retina

Question 2

Fibrous layer contains

Answer 2

Cornea and Sclera

Question 3

Vascular Coat contains

Answer 3

choroid, ciliary body, and iris

Question 4

Retina contains

Answer 4

Neural and retinal pigment epithelium

Question 5

Anterior segment is split into

Answer 5

Anterior chamber and posterior chamber

Question 6

Anterior segment contains

Answer 6

Aqueous humor, iris, ciliary body and muscle, lens, cornea, anterior sclera

Question 7

Posterior segment contains

Answer 7

Vitreous chamber with vitreous humor, visual retina, RPE, posterior sclera, and uvea

Question 8

Cornea

Answer 8

anterior 1/6 of eye, continuous with sclera
transparent and avascular
Made of 5 layers

Question 9

5 layers of Cornea

Answer 9

Corneal epithelium, Bowman’s membrane, Corneal stroma, Descemet’s membrane, Corneal endothelium

Question 10

Corneal epithelium

Answer 10

stratified squamous (nonkeratinized)
Mitotic activity high to replace injured epithelium
Have microvilli to help retain tears - prevents cornea from drying
Contain ferritin to protect from UV damage
Innervated by ophthalmic division of CN V

Question 11

Bowman’s membrane (anterior basement membrane)

Answer 11

Acellular basement membrane
Doesn’t regenerate
Terminates at Corneoscleral limbus
Strength and stability of cornea, barrier to prevent against infections

Question 12

Corneal stroma

Answer 12

middle layer of cornea, 90% of thickness
Collagen fibrils arranged in lamellae at right angle - transparency
Proteoglycans and Collagen V for spacing of collagen fibrils

Question 13

Descemet’s membrane (Posterior basement membrane)

Answer 13

Basement membrane of cornea endothelium, regenerates after injury, thickens with age, interwoven meshwork of fibers and pores
maintain normal curvature of cornea

Question 14

Corneal endothelium

Answer 14

faces anterior chamber of eyeball
Simple squamous epithelium with zonula adherens, zonula occludens, and desmosomes
Metabolic exchanges of cornea

Question 15

Sclera

Answer 15

white of eyeball
posterior 5/6s of eyeball
Tough fibrous connective tissue - maintain shape

Question 16

Tenon’s capsule

Answer 16

fascial sheath over surfvace of sclera

extraocular muscles insert

Question 17

Corneoscleral limbus

Answer 17

location of stem cells for corneal epithelium

Location of iridocorneal angle

Question 18

Uvea (Vascular coat)

Answer 18

Contains Iris, ciliary body, choroid

Question 19

Iris

Answer 19

most anterior portion of uvea
pupil, anterior and posterior pigment epithelium - give iris color
Contractile diaphragm of front of lens

Question 20

Dilator pupillae

Answer 20

opens pupil when contracts

Like rays of sun branching out from pupil

Question 21

Sphincter pupillae

Answer 21

closes pupil when contracts

wraps around pupil

Question 22

Ciliary body

Answer 22

Anterior to ora serrata

Lined by 2 layers of simple columnar epithelium separated by a basement membrane

Question 23

Inner layer of ciliary body epithelium

Answer 23

adjacent to aqueous humor, non-pigmented, fluid transporting epithelium

Question 24

Outer layer of ciliary body epithelium

Answer 24

pigmented - melanin

Ciliary channels

Question 25

Ciliary Processes

Answer 25

75 radial ridges Secretion and anchoring of zonule fibers - form suspensory ligament of lens Produces aqueous humor Form blood-aqueous barrier

Question 26

Flow of aqueous humor

Answer 26

Posterior chamber to pupil to anterior chamber to trabecular meschwork to Canal of Schlemm to venous system

Question 27

Ciliary muscle

Answer 27

longitudinal fibers stretch choroid Radial fibers flatten lens - distal vision Circular fibers reduce tension on lens - near vision

Question 28

Choroid

Answer 28

Dark-brown vascular sheet - prevents reflection of light waves Lies between sclera and retina Has two layers - Choriocapillary layer and Bruch's membrane

Question 29

Choriocapillary layer

Answer 29

inner vascular layer | richer in small blood vessels -nutrient to retina

Question 30

Bruch's membrane

Answer 30

innermost layer of choroid 5 layers: Basal lamina, Collagen fibers, Elastic fibers, Collagen fibers, Basal lamina of retina

Question 31

Photosensitive region of retina

Answer 31

Posterior to ora serrata | Vision portion of retina

Question 32

Optic disc

Answer 32

site where optic nerve joins retina | No photoreceptors - blind spot

Question 33

Macula lutea and fovea centralis

Answer 33

fovea centralis contains only cones Macula lutea surrounds fovea Greatest point of visual acuity on retina

Question 34

RPE

Answer 34

Pigmented layer Most external layer of retina below rods and cones - dark background for light to be picked up Simple cuboidal Mechanical separation occurs at this junction - detached retina

Question 35

Layer of rods and cones

Answer 35

Photoreceptive layer

Question 36

Rods

Answer 36

``` Most abundant Contains flattened discs Contain rhodopsion and retinal Light hyperpolaizes Low light intensity ```

Question 37

Cones

Answer 37

Sensitive to color (red, blue, and green) | Highly concentrated in Fovea centralis

Question 38

Outer limiting membrane

Answer 38

Apical ends of Muller cells = supportive cells | Between Rod and cone layer and Outer nuclear layer

Question 39

Outer nuclear layer

Answer 39

Contains nuclei of rods and cones

Question 40

Outer plexiform layer

Answer 40

Contains synapses between photoreceptor cells, bipolar cells, and horizontal cells

Question 41

Inner nuclear layer

Answer 41

Contains nuclei of bipolar, horizontal, amacrine, interplexiform, and Muller cells

Question 42

Inner plexiform layer

Answer 42

Contains synapses between bipolar, ganglion, interplexiform, and amacrine cells

Question 43

Ganglion cell layer

Answer 43

Contains cell bodies of multipolar ganglion cells | Single layer of cells throughout most of retina - none in fovea centralis, but several layers in macula lutea

Question 44

Layer of optic nerve fibers

Answer 44

Contains axons of ganglion cells forming the optic nerve | Travels to optic disc

Question 45

Inner limiting membrane

Answer 45

Basal laminae of Muller cells | Most internal membrane of retina

Question 46

Lens

Answer 46

Biconvex, transparent, elastic Avascular, no innervation Contains type IV collagen fibers and proteoglycans in lens capsule Cuboidal layer of cells on anterior surface of lens

Question 47

Conjuctiva

Answer 47

Stratified columnar epithelium with goblet cells | Secretions produce a tear film to protect cornea