Histo of Eye S2M1

The flashcards below were created by user lancesadams on FreezingBlue Flashcards.

  1. The wall of the eye consists of what layers
    • Corneoscleral coat (outer)
    • Uvea (middle vascular layer)
    • Retina (inner photosensitive layer)
  2. Where is the anterior chamber of the eye
    Between the cornea and the iris
  3. Where is the posterior chamber of the eye
    Between the iris and the lens
  4. Where is the Vitreous chamber of the eye and what does it contain
    • Between the lens and the retina
    • Vitreous humor
  5. What does the Vitreous humor consist of
    Hyaluronic acid and widely dispersed collagen fibers
  6. What does the Corneosclera consist of
    • Sclera (white portion)
    • Cornea (transparent portion)
    • These layers are continuous
  7. What is the Sclera made of
    Dense fibrous connective tissue that provides attachment for the eye muscles, and is interspersed with fibroblasts and few capillaries
  8. Limbus
    • Area of transition from the transparent collagen bundles of the cornea to the white opaque fibers of the sclera
    • "Area in Limbo"
  9. What are the five layers of the cornea
    • Epithelium
    • Bowmans capsule
    • Corneal stroma
    • Descemets membrane
    • Endothelium
    • "EBCDE"
  10. What type of cells are in the epithelium of the cornea
    Non-keratinized stratified squamous epithelium
  11. What protects the cornea from UV
  12. What is in the bowmans capsule of the cornea and what is its role
    • No cells, but contains collagen fibers
    • Helps to prevent against infection
  13. What is the thickest layer of the cornea and what is it made of
    • Corneal Stroma
    • Collagen, elastic fibers, interspersed fibroblasts
  14. What secretes the Descemets membrane
  15. What kind of cells make up the Endothelium of the cornea
    Simple Squamous epithelium
  16. What makes the cornea so sensitive
    It is highly innervated
  17. What are the three parts of the Uvea/Vascular coat
    • Choroid
    • Ciliary body
    • Iris
  18. What is the choroid
    • A highly vascularized layer that provides nutrients for the underlying retina
    • It also contains connective tissue and fibroblasts
  19. What is in the choroid that prevents the reflection of incident light
    Melanocytes, this is also what makes it black
  20. What is the role of the ciliary body
    • It contains the ciliary muscle that helps shape the lens
    • Its processes make the Aqueous humor
  21. The ciliary body is made up of what layers
    • Outer non-pigmented layer
    • Inner pigmented layer
  22. What happens when the ciliary muscles are contracted
    • The lens becomes thicker to focus on near objects
    • Relaxation makes it flatter
  23. What is the role of the iris
    Regulation of the amount of light that enters the eye by the contraction of diaphragm muscle (colored portion of the eye)
  24. What determines the color of the iris
    • 1. Melanin content of the iris pigment epithelium
    • 2. Melanin content within the iris stroma
    • 3. Cellular density of the iris stroma
  25. What makes the Aqueous humor, and what is made of
    • Ciliary epithelium in the posterior chamber
    • Similar to plasma, but much less protein
  26. Where can aqueous humor be found
    In the anterior and posterior chambers of the eye
  27. What is the purpose of the aqueous humor
    It provides nutrients and oxygen to the lens and cornea
  28. How does the aqueous humor get out of the anterior chamber
    Through the canal of Schlemm directly to the venous system
  29. In what direction does the Aqueous humor flow
    From the posterior chamber to the anterior chamber
  30. How much aqueous humor is drained a minute
    2-3 ul through the Canal of Schlemm
  31. Glaucoma
    Increased intraocular pressure damaging the optic nerve, often caused by excessive secretion of aqueous humor
  32. What is the lens of the eye made up of
    • 35% Protein
    • 65% Water
    • Encased in collagen IV membrane
  33. Crystallins
    Lens fibers that have lost their organelles and nuclei and are among the longest lived proteins in the body
  34. What is unique about the life of a lens
    It keeps growing throughout life and contains the longest lived proteins in the body
  35. Cataracts
    Then lens becomes clouded with age due to conformational changes or the cross linking of the lens proteins
  36. What must an image travel through before reaching the retina
    • Cornea
    • Aqueous humor
    • Lens
    • Vitreous body
  37. What is the chief refractive element of the eye
    The Cornea
  38. Emmetropia
    Ideal vision
  39. Myopia
    • Near-sighted (far objects are blurry)
    • Result of the cornea being too thick or eyeball is too long
  40. Hyperopia
    • Far-sighted (near objects are blurred) eyeball is too short
    • (Hyper = focused image is beyond the retina)
  41. What kind of lens is used to correct myopia and hyperopia
    • Myopia - Concave
    • Hyperopia - Convex
    • "My Opi (grandpa) lives in a cave"
  42. Astigmatism
    Unequal curvatures so the image isn't focused in one portion on the retina
  43. The retina consists of what two components
    • Neural retina
    • Retinal pigment epithelium
  44. Neural retina
    Top layer of the retina (closest to lens) that contains the light sensitive receptors and the complex neuronal networks
  45. Retinal pigment epithelium
    Bottom layer of the retina composed of simple cuboidal melanin containing cells and rests on the choroid
  46. Where is the neural retina derived from
    Inner layer of the optic cup
  47. What is the pigment epithelial layer of the retina derived from
    Outer layer of the optic cup
  48. What is a detached retina
    A seperation between the Neural retina and the Retinal pigment epithelium
  49. What provides the nutrients and metabolic support for the rods and cones
    Retinal pigmented epithelium
  50. Rods have what role in the eye
    They detect dim light (no color) and there is only one type
  51. What is the role of the Cones in the eye
    They are specialized receptors for bright light and color
  52. Cones have three types to detect what colors
    • Red
    • Blue
    • Green
  53. Why is a detached retina bad
    The neural receptors are detached from their source of nutrients from the Retinal pigment epithelium and therefore quickly die
  54. Fovea
    • A shallow depression of the retina and is the area of greatest visual acuity
    • Cell layers usually on top of the rods and cones are arranged off to the side here allowing light direct access
  55. Cones are highly concentrated where
    In the Fovea
  56. Macula
    A yellow pigmented zone that encircles the fovea
  57. Optic disk
    Exit site for the optic nerve, also known as the blind spot
  58. Rhodopsin/Iodopsin molecules
    • Molecules in the outer segments of the discs that absorb photons
    • Iodopsin are in the cones
  59. Upon the absorption of photons in the Rhodopsin molecules what happens
    Closure of Na+ channels in the plasma membrane hyperpolarizing the the membrane and reducing the rate of neurotransmitter release
  60. Light effects the neurotransmitters in the eye how
    There is a low rate of transmitters released and the cell hyperpolarizes
  61. When is there a high amount of transmitter release
    When it is dark
  62. How many Rhodopsin are there in one rod cell
    30 million
  63. Retinal
    The chromatophore of rods that is made from vitamin A
  64. What are the cell types in the retina, from external to internal
    • Ganglion cells
    • Amacrine cells
    • Bipolar Neurons
    • Horizontal cells
    • Photoreceptors
    • Muller cells (Supporting cells on sides)
    • "Gangli Americans Buy Heavy Cameras from Macys"
  65. Axons of the bipolar cells synapse with
    Dendrites of the ganglion cells
  66. Horizontal cells are found synapsing where
    With the synaptic junctions between the photoreceptor cells and the bipolar cells modulating synaptic activity
  67. Amacrine cells have what function
    They modulate synaptic activity connecting with axonal endings of bipolar cells and dendrites of ganglion cells
  68. Ganglion cells have what function
    • Their axons pass to the brain in the optic nerve
    • They are large and multipolar
  69. Muller cells have what function
    (Neuroglial cells) They envelope and support the neurons and the nerve processes of the retina
  70. The nuclei of rods and cones are found in what layer
    External nuclear layer
  71. Age Related Macular Degeneration (AMD)
    Loss of vision in the center of the field (macula) because of damage to the retina

    Leading cause of vision loss and blindness among the Americans who are over the age of 65
  72. Drusen
    Yellow deposits of the macula that starts AMD between the retinal pigment epithelium and the choroid
  73. What is the difference between dry AMD and wet
    Dry results from atrophy to the retinal pigment epithelial layer below the retina

    Wet is caused by abnormal blood vessel growth in the choriocapillaries leading to blood and protein leakage below the macula
Card Set:
Histo of Eye S2M1
2011-08-12 13:35:12
Ross S2M1

Show Answers: