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16 Cards in this Set
- Front
- Back
3 tunics in the eye..
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1) Fibrous (outer, protective)
2) Vascular (just inside, blood supply) 3) Nervous (inner, receptors) |
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The fibrous tunic is made up of 2 parts...
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The cornea and sclera
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Cornea=
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-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 |
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sclera=
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-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 |
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The vascular tunic is made up of 3 parts..
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-choroid
-ciliary body -iris |
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choroid=
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-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 |
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ciliary body=
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-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 |
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-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 |
the iris
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-smooth muscle fibers
-when contracted, pupil is smaller -parasympathetic- fibers travel with oculomotor nerve |
circular muscle in iris
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-modified contractile epithelial cells (myoepithelial)
-when contracted, pupil is bigger -sympathetic- fibers run along carotid arteries |
radial muscle in iris
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Nervous tunic =
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the only place where blood vessels can be viewed directly
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retina =
and is made up of 2 parts |
-posterior 3/4 part of the eye
-supplied by the central artery of the retina 1) the pigment epithelium 2) the neural layer |
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Pigment epithelium =
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-sheet 1 layer thick of cuboidal, melanin containing cells
-need these colors so light doesn't bounce around in the eye |
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Neural part =
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-photoreceptor cells and associated neurons
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Ora serrata =
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where the retina attaches into the choroid
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Detached retina =
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-blurry images in field of vision
-pigmented and neural layers separate |