Term
| What are the 4 layers of the eye? |
|
Definition
1. Sclera
2. Cornea
3. Choroid
Retina |
|
|
Term
|
Definition
Dense
White, Opaque
Protective coat
that covers 85% of the eye |
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Term
| The Cornea covers what % of the eye |
|
Definition
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Term
| The Cornea is a thin tear film that has what kind of properties |
|
Definition
| Refractory properties that bend the light rays |
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|
Term
| The choroid is said to be |
|
Definition
| vascular--has blood supply |
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Term
| The Retina has what two layers? |
|
Definition
| the neuronal and outer pigmented layer |
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Term
| Which parts of the eye are said to be transparent? |
|
Definition
1. Cornea
2. Aqueous Humor
3. Vitreous
4. Lens
5. Retina |
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|
Term
| What is the function of the lens? |
|
Definition
| To focus the incoming image into the retina |
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|
Term
| The Vitreous has what functions |
|
Definition
1. Shock absorber
2. structural support
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|
|
Term
| What % of volume does the Vitreous make in the eye? |
|
Definition
|
|
Term
|
Definition
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|
Term
| Light comes in first through the _________ then through the _______ to focus in the _________ |
|
Definition
1. Cornea
2. Lens
3. Retina
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|
Term
| What is refractive power measured in? |
|
Definition
|
|
Term
| The cornea has what fraction of the 59 diopters that have the ability to bend light? |
|
Definition
|
|
Term
| The lens has what fraction of diopters that are able to bend light? |
|
Definition
|
|
Term
| True/False: The lens is vascular |
|
Definition
| False: it is avasular so it has no blood supply |
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Term
| The lens of the eye has __________ anterior and posterior sides |
|
Definition
|
|
Term
| Accomodation is the ability to ________ |
|
Definition
| increase the lens refractive power |
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|
Term
| What connects the lens to the ciliary body? |
|
Definition
|
|
Term
| When you bring an object closer the ciliary body_________ and relaxes the ____________ |
|
Definition
1. Contracts
2. lens ligaments |
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|
Term
| When lens become relaxed what happens to their shape? |
|
Definition
| They become more spherical, convex and thicker |
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|
Term
| Contraction of the ciliary body is controlled by the |
|
Definition
| Parasympathetic nerve signals |
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Term
| The closer the object the _________________ |
|
Definition
| stronger and more precise the focusing system has to be. |
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Term
| A loss in the power of accomodation is called |
|
Definition
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|
Term
| Presbyopia increases with age and causes the addition of ___________ which makes the lens less ______ and leads to biofocals being needed |
|
Definition
1. Fibers to the outermost portion of the lens
2. Elastic but thicker
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|
Term
| In Presybopia the eye remains focused on ____________ |
|
Definition
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|
Term
| The Lacrimal System produces ___________ via the ____________ |
|
Definition
1. Tears
2. Lacrimal gland |
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|
Term
| Tears are collected by the _________ and ______ |
|
Definition
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|
Term
| Tears are emptied into the ________ |
|
Definition
|
|
Term
| _____________ empties the tears to nasal cavity |
|
Definition
|
|
Term
|
Definition
1. 98% water
2. 1.5 % of NaCl
3. K+
4. albumin
5. Glucose
6. Lysosomez
7. Immunoglobins |
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|
Term
| Glucose in tears serves what function |
|
Definition
|
|
Term
| Lysosomez and Ig serve what function in the eyes |
|
Definition
| Protection against infections |
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|
Term
| Tears serve what 3 functions |
|
Definition
1. Provide wet and protect cornea and conjuctiva
2. Cleans and provides nutrients to cornea
3. Protects against infection |
|
|
Term
|
Definition
| Thin layer of mucous membrane that line the outer surface of the eye and the anterior surface of the eyelids |
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|
Term
| A disorder of the conjuctiva is called |
|
Definition
| Conjunctivitis or aka pink eye |
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|
Term
| Conjuctivitis is due to _____ |
|
Definition
| an inflammation caused by bacteria, virus, allergens, or chlamydia |
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|
Term
| The Aqueous Humor is made by the ________ |
|
Definition
| Ciliary process epithelium |
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|
Term
| Aqueous Humor in found between the _____ and the _______ where it provides nutrients to it |
|
Definition
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|
Term
| Aqueous Humor outflows from the ________ to ____________ |
|
Definition
1. Trabecular Meshwork
2. Schlemns Canal |
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|
Term
| In the Plasma Membrane there are ___________ that provide energy to make the Aqueous Humor |
|
Definition
|
|
Term
| What regulates the Na-K-ATPase on the P.M. of the epithelium cell? |
|
Definition
|
|
Term
| How does regulation of Na-K-ATPase occur? |
|
Definition
1. ACh binds to its receptor on PM
2. Releases Ca2+
3. Ca2+ binds to Calmodulin receptor on the NOS and activates it
4. NO then binds to a sGC (soluble Guanine Cyclase)
5. Converts to cGMP
6. cGMP binds to a PKG (protein kinase G)
7. cGMP also binds to RRR (reversible protein phosphorylation) that decreases the Na-K-ATPase activity
End goal: Decrease the formation of Aqueous Humor |
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|
Term
| The Aqueous Humor aid in ______ |
|
Definition
| Maintaining intraocular pressure |
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|
Term
| To maintain the intraocular pressure what two things must be equal? |
|
Definition
| The rate of secretion and the rate of outflow of the aqueous humor |
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|
Term
| Improper regulation of Intraocular pressure leads to what? |
|
Definition
|
|
Term
| What kind of agents decrease the cell volume thus increasing the rate of outflow of aqueous humor? |
|
Definition
|
|
Term
| What kind of agents disrupt the actin cytoskeleton thus icnreasing the aqueous humor outflow? |
|
Definition
|
|
Term
| What is the main function of the retina? |
|
Definition
| To recieve visual images and transmit them to the brain |
|
|
Term
| The retina is split up in two layers, what are they? |
|
Definition
The outer layer that has melanin
and the Neural (inner layer) that has receptors |
|
|
Term
| In the Neuronal retina what are the three layers that make it up? |
|
Definition
1. posterior photoreceptors
2. Middle biopolar cells
3. Inner layer of ganglion cells with photoreceptros |
|
|
Term
| What are the 2 photoreceptors in the eye? |
|
Definition
|
|
Term
|
Definition
Black and white
Used for night vision |
|
|
Term
|
Definition
|
|
Term
| What is phototransduction? |
|
Definition
| A process where incoming light is converted to an electrical signal to be sent to the brain |
|
|
Term
| What region of the cone is light sensitive? |
|
Definition
|
|
Term
| Where is their a high density of cones? |
|
Definition
| In the macula because there the fovea has a high amount of it |
|
|
Term
| What are the three cone colors? |
|
Definition
|
|
Term
| In rods, what visual pigment is responsible for trapping the light? |
|
Definition
|
|
Term
| Rhodopsin is made up of a protein called __________ and a vitamin A derived pigment called ________. |
|
Definition
|
|
Term
| What absorbs the light that is not absorbed by Rhodopsin? |
|
Definition
|
|
Term
| Rhodopsin has a chromophore called what? |
|
Definition
| 11-cis retinal that binds to opsin |
|
|
Term
| During light capture the cis retinal turns into? |
|
Definition
|
|
Term
| Describe the steps that occur during light capture |
|
Definition
1. Rhodopsin is broken down into retinal and opsin
2. 11-cis retinal to all trans retinal
3. Opsin is activated
4. Rhodopsin is now Metarhodopsin
5. GTP binds to transducin
6. beta/gamma dissociate from G-protein
7. alpha/gprotein bind to Phosphodieasterasen(PDE) to activate it
8. PDE degrades cGMP to GMP
9. CNG (cyclic nucleotide gated) channels close |
|
|
Term
| If the CNG channels close during light capture what 2 effects does it have? |
|
Definition
1. decrease in Ca2+ influx
2. Hyperpolarization of membrane
|
|
|
Term
| A lower Ca2+ concentration leads to what? |
|
Definition
| resynthesis of cGMP by activating the cyclase activating protein (GCAP) |
|
|
Term
| What makes up the optic nerve? |
|
Definition
| all the axons from the retinal ganglion cells |
|
|
Term
| During the dark, what is reformed? |
|
Definition
|
|
Term
| How is Rhodopsin reformed? |
|
Definition
1. all trans retinal is converted back to 11-cis retinal
2. combines with opsin
|
|
|
Term
| If you have a reduced sensitivity to light, what kind of deficiency do you have? |
|
Definition
|
|
Term
| Light adaptation decreases what? |
|
Definition
1. sensitivity of eye to light
2. Concentration of the photosensitive chemicals in rods and cones |
|
|
Term
| Hyperopia, or farsightedness is a ________ |
|
Definition
| Decrease in refractive power |
|
|
Term
| With hyperopia the image is focused behind the retina, so __________ objects are clear but __________ are blurry. |
|
Definition
|
|
Term
| How do you correct Hyperopia? |
|
Definition
|
|
Term
| In hyperopia, the eyeballs are |
|
Definition
|
|
Term
| Myopia is when the eyeballs are too |
|
Definition
|
|
Term
| Myopia, or nearsightedness, can see ________ objects fine, but _______ objects are blurry. |
|
Definition
|
|
Term
| In Myopia, the distant objects image is focused where in the retina? |
|
Definition
|
|
Term
| With Myopia, is there is an increase in ______ |
|
Definition
|
|
Term
| How do you correct Myopia? |
|
Definition
|
|
Term
| What is it called when you have uneven curvature in the cornea? |
|
Definition
|
|
Term
| What percentage of US people have myopia? |
|
Definition
|
|
Term
| Someone with astigmatism which objects are blurred? |
|
Definition
|
|
Term
| What happens to the light rays in astigmatism? |
|
Definition
| The light rays focus in two different areas in the retina, which causes a blurry picture |
|
|
Term
| The visual cortex is located where? |
|
Definition
| In the occipital lobe and provides visual sensation and perception |
|
|
Term
| What % of people with myopia also have astigmatism? |
|
Definition
|
|
Term
| Cataracts does not do what? |
|
Definition
|
|
Term
| How do you treat Cataracts? |
|
Definition
|
|
Term
| What is the most common cause of visual loss? |
|
Definition
|
|
Term
| If someone is color blind what happens to their sight? |
|
Definition
They mismatch colors
or confuse them |
|
|
Term
| What is it called when you have a degeneration of the retinal photoreceptors? |
|
Definition
|
|
Term
| True/False: Diabetic Retinopathy causes the retinal capillary walls to thicken, hemorrage and form weak blood vessels? |
|
Definition
|
|
Term
| What seems to be the treatment for Diabetic Retinopathy? |
|
Definition
|
|
Term
| What is the 3rd cause of blindness? |
|
Definition
|
|
Term
|
Definition
Age-related Macular Degeneration
(disease associated with a decrease in vision with increase in age) |
|
|
Term
|
Definition
| Blood vessels grow under the macula and raise it from its normal position at the back of the eye |
|
|
Term
| If you see straight lines instead of wavy lines then you probably have what? |
|
Definition
|
|
Term
| In Dry AMD the cones in the macula break down and create what |
|
Definition
| Blurr spots in the cneter of your vision |
|
|
Term
| What are the three ways to treat wet AMD? |
|
Definition
1. argon laser photocoagulation of extrafoveal
2. Chorodial neovascularisation (CNV)
3. Photodynamic therapy of sub foveal |
|
|
Term
| In Glaucoma you have what? |
|
Definition
1. Optic Disk cupping
2. Axonal loss
3. Visual field loss - the area where objects are seen |
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