Term
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Definition
-photosensitive -partially surrounded by the orbits -derived from: surface ectoderm outpocketing of prosencephalon
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Term
Anatomical Components of the EYE (4) |
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Definition
1. Globe -provides support for other parts of the eye 2. Lens -image focus 3. Photosensitive Cells -receive visual stimuli 4. Neurons -transmit visual information to the brain
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Term
Structural Layers of the EYE (3) |
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Definition
1. Outer Layer (tunica fibrosa) -cornea and sclera 2. Middle Layer (vascular) -choroid, ciliary body, and iris (uveal tract) 3. Inner Layer -retina |
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Term
Compartments in the EYE (3) |
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Definition
1. Anterior Chamber -between cornea, and iris and lens -filled with aqueous humor 2. Posterior Chamber -between iris, ciliary body, zonule, and lens -filled with aqueous humor
3. Vitreous Space -bounded by the lens and retina
-filled withgelatinous vitreous body -maintains shape of eye -protects retina from trauma of rapid move |
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Term
Tunica Fibrosa - Outer Layer (2 components) |
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Definition
1. Sclera = "whites of the eyes" 2. Cornes = anterior, transparent part of the globe |
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Term
| Sclera = "whites of the eyes" |
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Definition
-dense fiberous connective tissue -many multidirectional collagen bundles parallel to surface of eye -outer surface of sclera = episclera -loose connective tissue
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Term
| Cornea = anterior, transparent part of the globe |
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Definition
-multilayered -avascular -outer non-keratinized stratified squamous epitheliu -high degree of mitotic activity -richly innervated -vascular supply along periphery -nutrients diffuse through these vessels -merge into Schlemm's canal -drains anterior chamber -empties into regional venous system
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Term
Vascular - Middle Layer (3 structures) |
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Definition
-structures comprise the uveal tract 1. Choroid 2. Ciliary Body 3. Iris |
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Term
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Definition
-deeply pigmented (numerous melanocytes) -many blood vessels -loose connective tissue -abundent collagen and elastic fibers -leukocytes ->lympocytes, mast cells, macrophages, and plasma cells -choriocapillary layer -vascularized -responsible for nutrition of retina -compromise this = retina damage |
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Term
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Definition
-key for image focusing -widening of choroid adjacent to lens -appears triangular in shape in cross-section -loose connective tissue than encases ciliary muscle --> ciliary muscle --> ciliary processes |
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Term
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Definition
-smooth muscle fibers -insert on both sclera + multiple point on ciliary body -allow for: -stretching of choroid -releasing tension on lens = proper visual accommodation (image focusing) |
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Term
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Definition
-envaginations of ciliary body -loose connective tissue core -covering of simple columnar epithelium -Oxytalan (zonule) fibers emerge -insert on lens capsule (hold it in place) Constituent cells of ciliary processes are responsible for secretion of aqueous humor |
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Term
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Definition
-projection of choroid -partially covers the lens -leaves and aperture -known as pupil
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Term
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Definition
-rough anterior surface -covers poorly vascularized connective tissue -contains melanocytes -below = connective tissue (highly vascularized) -smooth posterior surface -covered by 2 layers of epithilium inner layer = melanocytes + pigmented outer layer = cellular myofilaments that make up dilator pupillae muscle
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Term
Iris Regulates Amount of Light Entering (adaptation) |
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Definition
-regulated by melanocytes and dilator pupillae muscle -sphincter pupillae muscle = concentric bundles of smooth muscle surrounding the pupil (regulates light inflow) -dilator pupillae muscle = processes sympathetic innervation -sphincter pupillae muscle = processes parasympathetic innervation |
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Term
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Definition
-oviod, highly elastic structure 1. Lens capsule 2. Subcapsular epithelium -simple cuboidal or columnar only found on anterior surface 3. Lens Fibers -below the epithelium -elongated subcapsular epithelial cells -no organelles = transparent and filled with crystallins (proteins)
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Term
Retina - Inner Layer (2 layers) |
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Definition
-photosensitive elements in posterior portion -2 distinct layers 1. Pigment Epithelium 2. Neural (optical) Retina The retina posterior to the ora serrata is sensitive to light and transmits this information to the brain via th eoptic nerve. |
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Term
| Retina - Pigment Epithelium |
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Definition
-single layer of columnar cells -process and transport vit A to photoreceptor cells -produce melanin -absorb light after stimulation of the photoreceptors |
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Term
Retina - Neural Optical Retina (5 Layers) |
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Definition
-detects light -composed of many types of neurons and synapses 1. outer layer of rods and cones 2. external plexiform layer 3. bipolar neurons 4. internal plexiform layer 5. ganglion cells
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Term
Retina - Neural Optical Retina Outer Layer of Rods and Cones |
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Definition
Several Functional Regions: -single dendrite that's sensitive to light -component of outer segment -inner and outer segments -nuclear region -synaptic region
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Term
Retina - Neural Optical Retina External Plexiform Layer |
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Definition
Contains: -synapses between rods and cones -bipolar neurons |
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Term
Retina - Neural Optical Retina Bipolar Neurons |
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Definition
-integrate rods and cones with ganglion cells
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Term
Retina - Neural Optical Retina Internal Plexiform Layer |
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Definition
Contains: -synapses between bupolar cells and ganglion cells |
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Term
Retina - Neural Optical Retina Ganglion Cells |
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Definition
-transmit visual info to brain via their collective axons -collective axons become optic nerve ***Light first passes through ganglion cells (they are closest to vitreous body), then bipolar neurons, before it hits rods and cones.*** Gangion Cells --> Bipolar Neurons --> Rods + Cones |
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Term
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Definition
1. rods 2. cones 3. diffuse bipolar cells 4. monosynaptic bipolar cells 5. ganglion cells 6. horizontal cells 7. amacrine cells 8. supporting cells |
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Term
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Definition
-highly photosensitive -resposive to LOW LIGHT conditions -elongated outer segment = light sensitive part -contains many stacked membranous disks Disks contain: Rhodopsin - interaction with light is 1st step in vision
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Term
Cells of the Retina Cones |
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Definition
-elongated conical processes = responsive to COLOR and HIGER INTENSITY LIGHT -less than 5% of photoreceptos -membraneous disks (in outer segement) formed by invaginations of cell membrane -visual pigment = IODOPSIN = sensitive to RGB light -provide better visual perception than rods |
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Term
Cells of the Retina Diffuse Bipolar Cells |
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Definition
synapse with 2+ photreceptors (multiple rods and cones) |
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Term
Cells of the Retina Monosynaptic Bipolar Cells |
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Definition
synapse with 1 photoreceptor (1 rod or cone) |
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Term
Cells of the Retina Ganglion Cells
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Definition
neurons whose axons converge to form the optic nerve may be diffuse or monsynaptic |
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Term
Cells of the Retina Horizontal Cells |
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Definition
connect photoreceptors to one another communication b/w rods and cones |
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Term
Cells of the Retina Amacrine Cells |
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Definition
| connect ganglion cells to one another |
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Term
Cells of the Retina Supporting Cells |
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Definition
Consist of: -microglia -astrocytes -large, branching Muller cells |
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Term
Accessory Structure of the Eye (3) |
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Definition
1. Conjunctiva 2. Eyelids 3. Lacrimal Glands |
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Term
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Definition
-mucous membrane -covers cornea and inner surface of the eyelid -stratified columnar epithelium -goblet cells |
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Term
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Definition
-protective fold of skin -Contains 3 types of Glands 1. Meibomian Gland -sebaceous gland -does NOT empty into hair follicle -produces lipid-rich surface over tear film -prevents evaporation 2. Glands of Zeis -sebaceous glan -empty into eyelash follicle 3. Glands of Moll -modifies sweat gland -empty into eyelash follicle
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Term
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Definition
-secrete tears -serous lubricating fluid rich in lysozyme -compund tubuloacinar gland -resembles parotid tissue
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Term
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Definition
-adjacent to optic nerve -highest visual acuity -structurally different from retina -only external plexiform layer |
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Term
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Definition
| no retina in front of optic nerve |
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