LS2:Sensory Systems part 2

Card Set Information

LS2:Sensory Systems part 2
2012-06-13 04:11:22

Show Answers:

  1. Auditory systems
    1.Use mechanoreceptors to convert pressure waves to receptor potentials
  2. Fires an action potential
    • 1.Stretch receptors:Ionotropic
    • 2.Olfaction:metabotropic
  3. Don't fire action potentials
    • 1. Hearing:Ionotropic
    • -releases neurotransmitter
    • 2.Vision:metabotropic
  4. what do pinnaedo?
    collect sound waves and direct them to the auditory canal
  5. what does the Tympanic membrane cover and why does it vibrate?
    • 1.Covers the end of the auditory canal
    • 2.Vibrates in response to pressure waves
  6. Middle ear
    • 1.Air filled cavity
    • 2.Equilibrates air pressure between middle ear and the outside
  7. by what does the middle open to the throat?
    the Eustachian tube
  8. Ossicles
    • 1.Malleus, incus, stapes
    • 2.Transmit vibrations of tympanic membrane to the oval window of the cochlea
  9. Inner ear
    1.Fluid filled cavity
  10. Inner ear canals
    • 1.Vestibular system: for balance
    • 2.Cochlea: for hearing
  11. Cochlea
    • 1 Tapered and coiled chamber composed of three parallel canals separated by
    • -Reissner's membrane
    • -Basilar membrane
  12. Three canals of Cochlea
    • 1.Upper and lower
    • -have high Na+ concentrations, move vibrations
    • 2.Middle
    • -have high K+ concentration, filled with endoli
  13. Round window
    • 1.Flexible membrane at the end of the canal
    • -relieves pressure
  14. Organ of Corti
    • 1.Transduces pressure waves into action potentials
    • 2.Contains hair cells with stereocilia
  15. where does the organ of Corti sit?
    on the basilar membrane
  16. what can the hair cells in the organ of Corti do?
    • 1.They bend and create a graded potential that alter neurotransmitter release
    • 2.Translate physical force to something nervous system can use
    • 3.Outer hairs: not important
    • 4.Inner hairs: these translate physical force into transmitter
    • release in the auditory nerve
    • 5.Mechanorecpetors, but do not fire action potentials, release neurotransmitters
  17. what causes basilar membrane to move?
  18. Action potentials stimulated by mechanoreceptorsat different positions along organ of Corti aretransmitted to the brain via....
    the auditory nerve
  19. Conduction deafness
    1.Loss of function of tympanic membrane or ossicles
  20. When you activate the basilar membrane....
    • 1.Sound pressure moves from the upper cana of the cochlea
    • 2.travels down through the lower canal
    • 3.relieves pressure through the round window
  21. Nerve deafness
    • 1.Damage to inner ear or auditory nerve pathways
    • 2.Hair cells in the organ of Corti can be damaged by loud sounds
    • 3.Damage is cumulative and irreversible
    • Ex.Loud music
  22. Hair cells
    1.Mechanoreceptors in organs of hearing and equilibrium
  23. Bending of stereocilia can_____or_____ion channels
    open or close
  24. Hair cells: the plasma membrane can be depolarized or hyperpolarized
    • 1.K+ flows through stereocilia to depolarize cells
    • 2.Ca+ rushes in, causes transmitter release
  25. Rhodopsins
    pigment all animals use
  26. Photorecpetor cells
    Metabotropic sensory cells that transform light into action potentials
  27. Light travels to the retina...
    • 1.optic nerve
    • 2.Ganglion cells(first cells to fire action potential)
    • 3.Photoreceptors
    • 4.Pigmented epithelium
  28. Rod cells have
    • 1.Outer segment
    • -discs of plasma membrane containing rhodopsin to capture photons
    • -where light is translated
    • 2.Inner segment
    • -contains the nucleus and organelles
    • 3.Synaptic terminal
    • -wherethe rod cell communicates with other neurons
  29. Rhodopsin
    • -Molecule consists of:
    • 1. opsin(a protein)
    • 2. a light-absorbing group, 11-cis-retinal
  30. where do Rhodopsin molecules sit?
    in plasma membrane of a photoreceptor cell
  31. When 11-cis-retinal absorbs photons lights......
    • -Changes to the isomer all-trans-retinal
    • -Changes the conformation of opsin
    • How it works:
    • 1. Transducin gets activated by rhodopsin
    • 2.Binds and activates PDE, which changes cGMP to GMP
    • -Dark room: depolarizes and opens Na+ and Ca2+channel
    • -light hits eye: hyperpolarizes and closes channel ,cGMP can bind
  32. Bleaching
    in vertebrate eyes, the retinal and opsin eventually separate
  33. Rod cell
    • 1.Type of vertebrate photoreceptor
    • 2.Modified neuron that does not produce action potentials
  34. Membrane potential of rod cell
    • 1.No light = -35mV
    • 2.With light = hyperolarizes the rod cell, less transmitter
  35. Cells that are responsible for night vs color vision
    • 1.Rod cells:Night vision
    • 2.Cone cells: color vision
  36. In dark, whats happening with sodium and calcium?
    • 1. lots of sodium and calcium are flowing into the cell
    • 2.cyclic GMP is bonded tochannels
  37. In light, what is happening with transducin?
    • 1.Transducin activates PDE
    • 2. PDE convertscGMP to GMP
    • 3. Na+ channels close
    • 4.Membrane is hyperpolarized
  38. Foeva
    area where cone cell density is highest
  39. color blindness
    Loss of function of one or more types of cone cells
  40. How many types of cone cells do humans have?
  41. How many layers of neurons does the retina have?
  42. What forms the optic nerve?
    Axxons from ganglion cells
  43. how are photoreceptor cells connected to ganglion cells?
    via bipolar cells
  44. When the rod is in the dark, cells dump....
    glutamate(excitatory transmitter)
  45. Horizontal cells
    form synapses with bipolar cells and phtoreceptors
  46. Amacrine cells
    form local synapses with bipolar cellsand ganglion cells
  47. Light activates ____bipolar cells
    • 1. ON bipolar cells
    • -metabotropic
    • -depolarize in light
    • -hyperpolarize in dark
  48. Dark activates _____bipolar cells
    • 1. OFF bipolar cells
    • -ionotropic
    • -depolarize in dark
    • -hyperpolarize in light