Vision 1 Cont.

Front 1

3 tunics in the eye..

Back 1

1) Fibrous (outer, protective)
2) Vascular (just inside, blood supply)
3) Nervous (inner, receptors)

Front 2

The fibrous tunic is made up of 2 parts...

Back 2

The cornea and sclera

Front 3

Cornea=

Back 3

-CT matrix-small fibers
-transparent, low h2o content
-stratified squamous outer surface
-simple squamous inner surface
-non vascular
-covers the iris
-helps focus light on the retina
-outer epithelium layer is continuous with bulbar conjunctiva

Front 4

sclera=

Back 4

-firm, white, dense CT w/ elastic fibers
-has blood vessels and nerves
-posterior part is pierced by optic foramen and cranial nerve #2
-covers whole eyeball except for cornea
-it shapes the eyeball, makes it more rigid and protects the inner parts

Front 5

The vascular tunic is made up of 3 parts..

Back 5

-choroid
-ciliary body
-iris

Front 6

choroid=

Back 6

-lines most of the inner surface of the sclera
-provides nutrients to retina
-very vascular
-it is a dark brown membrane
-melanocytes give it the dark color

Front 7

ciliary body=

Back 7

-a thickened extension of the choroid
-forms a muscular ring around the lens
-has ciliary processes with ciliary ligaments that support and change the lens shape
-the lens is suspended from the suspensory ligaments

Front 8

-colored part of the eye
-controls the diameter of the pupil
-contains circular and radial muscles
-anterior ext. of the choroid
-pupil is central opening

Back 8

the iris

Front 9

-smooth muscle fibers
-when contracted, pupil is smaller
-parasympathetic- fibers travel with oculomotor nerve

Back 9

circular muscle in iris

Front 10

-modified contractile epithelial cells (myoepithelial)
-when contracted, pupil is bigger
-sympathetic- fibers run along carotid arteries

Back 10

radial muscle in iris

Front 11

Nervous tunic =

Back 11

the only place where blood vessels can be viewed directly

Front 12

retina =
and is made up of 2 parts

Back 12

-posterior 3/4 part of the eye
-supplied by the central artery of the retina
1) the pigment epithelium
2) the neural layer

Front 13

Pigment epithelium =

Back 13

-sheet 1 layer thick of cuboidal, melanin containing cells
-need these colors so light doesn't bounce around in the eye

Front 14

Neural part =

Back 14

-photoreceptor cells and associated neurons

Front 15

Ora serrata =

Back 15

where the retina attaches into the choroid

Front 16

Detached retina =

Back 16

-blurry images in field of vision
-pigmented and neural layers separate