Card Set Information

2011-06-07 04:01:36
eyes vision

eyes, vision
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  1. Ansosmia
    results when one cannot smell due to damage of olfactory nerve or zinc deficiency
  2. Eye & Vision
    40% of cerebral cortex is dedicated to processing images captured by the eye and the eye is protected by a cushion of fat within the optical orbit
  3. Eyebrows
    shade from sunlight & keep sweat away from the eyes
  4. eyelids
    used for blinking & have glands producing eye grit. Tarsal glands release oil that forms a film & slows water evaporation
  5. Conjunctiva
    transparent mucous membrane covering inner surfaces of eyelids (white of the eye) and is known as pink eye when becomes inflammed due to bacteria or virus
  6. Lacrimal apparatus
    consists of lacrimal gland & lacrimal duct secreting a fluid to keep eye moist with blinking eye spreading fluid on surface and lacrimal fluid killing the bacteria
  7. extrinsic eye muscles
    the six muscles moving the eye
  8. Structures that protect the eye
    • eyebrows
    • eyelids
    • conjunctiva
    • lacrimal apparatus
    • extrinsic eye muscles
  9. anatomy of eyeball
    designed to protect photoreceptors, capture & process & image.
  10. Fibrous tunic
    makes up sclera & cornea
  11. cornea
    transparent (avascular containing pain receptors) & allows light to enter eye...easily damaged, but has good regeneration ability
  12. Vascular tunic
    composed of choroids, ciliary body, and iris
  13. choroid
    dark in color containing melanin to absorb light; highly vascularized
  14. ciliary body
    encircles lens & helps to adjust it
  15. iris
    • colored part of eye with the color coming from amount of melanin in iris body
    • (note: iris has smooth muscles controlling size of pupil with the papillary light reflex protecting eye from light damage)
  16. pupil
    opening of iris
  17. sensory tunic
    also called retina & contains melanocytes and a sheet of nervous tissue made up of photoreceptors (rods & cones)
  18. Rods & Cones
    • Rods: dark & grays (do not regenerate themselves)
    • Cones: bright (do not regenerate themselves)

    ******Rods & cones contact a bipolar neuron synapsing with ganglion cells. Axon of the ganglion cells enter optic nerve & carry stimulus to occipital lobe
  19. macula lutea
    "yellow spot" at posterior pole
  20. fovea centralis
    a pit at its center & is the area containing only cones providing visual acuity
  21. optic disc
    (blind spot): where retina gathers to & from optic nerve and lies medial to fovea centralis
  22. retina has...
    • macula lutea
    • fovea centralis
    • optic disc
  23. Internal chambers & fluids
    fluids in these chambers nourish eye tissues & maintain appropriate pressure

    • The posterior chamber filled with vitreous humor
    • The anterior chamber filled with aqueous humor
  24. posterior chamber
    filled with vitreous humor that regulates eye pressure, maintains retina against the eye wall, and allows the image to travel across the eye to the retina. This is formed as an embryo and lasts the entire life time.
  25. anterior chamber
    filled with aqueous humor, it is more liquid than vitreous humor, periodically regenerated, and drains into scleral venous sinus.
  26. lens
    a transparent disc that changes shape to adjust to focus light. The lens sends images that are upside down and reverse from left to right. The cerebral cortex reverses the image. With age the lens thickens and becomes less flexible reducing its ability to focus light.
  27. eyes are designed to see best where...
    far distances.
  28. pupil constricts when what?
    when looking at closed up objects
  29. Visual pathways of image
    • Image travels from retina to optic nerve to optic chiasma to optic tract (This tract travels to midbrain some tract branch out to control eye reflexes, other branch to the hypothalamus). From the hypothalamus to the thalamus to cerbral cortex (visual cortex in occipital lobe). Images are sent at different angles from both eyes, the brain process that information to create just one image
    • .-->retina--->
    • optic nerve--->
    • optic chiasma--->
    • optic tract--->
    • hypothalamus-->
    • thalamus-->
    • cerebral cortex (in occipital lobe)