Physio Test 4 pt2

Card Set Information

Physio Test 4 pt2
2014-05-17 18:02:28

Test 4
Show Answers:

  1. Astigmatism
    Blurry images at all distance; unequal curves on lens and/or cornea, creating discontinuous image on the retina
  2. Outer segment
    Contain membrane-bound discs with pigments that absorb and react to light
  3. Rods
    Pigment discs stacked like pennies all the way to the base, membranes are DISTINCT from the plasma membrane
  4. Cones
    Pigment discs taper off toward the base, membranes are CONTINUOUS with the plasma membrane
  5. Opsin
    Trans membrane protein in in the membrane of pigmented discs of rods and cones
  6. Retinal
    • Light absorbing molecule that changes shape when struck by a photon of light
    • Vitamin A = precursor to retinal
  7. Rhodopsin
    • Visual pigment in rods
    • Membranes of pigmented discs of outer segment
  8. Bleaching of pigment
    Breakdown of rhodopsin after thew absorption of light
  9. Excitation of Rods
    • Rhodopsin
    • Bleaching of pigment
  10. Excitation of cones
    • Photopsins
    • Different colors
    • Color blindness inherit gene for one of the photon proteins that is deficient, most common are red and green mutations
  11. Photopsins
    3 distinct pigments in cones are sensitive to 3 different parts of the visible spectrum
  12. Blue cones
    Maximum sensitivity at 455nm
  13. Green cones
    Maximum sensitivity at 530nm
  14. Red cones
    Maximum sensitivity at 625nm
  15. Different colors
    Differential activation of each of the three different cones
  16. Light adaptation
    • From very dark to very bright
    • Rhodopsin in rods is quickly bleached out
    • Cones are activated to take over (5min)
    • Consensual pupil reflex - constriction
  17. Dark adaptaion
    • Very bright to very dark
    • cones are gradually cease to be stimulated
    • Bleached out rods can produce rhodopsin
    • Pupillary dilation - pupils increase in size
  18. Nyctalopia
    • Night blindness
    • Deficiency in function of rods during dim-light situations
    • Vitamin A deficiency in general cause
  19. Binocular vision
    Two eyes have overlapping regions of the visual field, so that the same point is seen from slightly different angels
  20. Depth perception
    A result of binocular vision in which person can perceive relative distances based on information gather in both eyes
  21. Vibration of medium
    • Sound travels in compression waves through a particular medium
    • Solid = fastest
    • Gas = slowest
  22. Sound as a wave
    The series of high pressure and low pressure areas are called "compressions" and "rarefactions", respectively/
  23. Sine wave
    Graphic representation of areas of compression and rarefaction of a sound wave
  24. Wavelength
    The distance between 2 areas of compression for a given sound wave
  25. Frequency
    The number of waves that pass a given point in one second (1/s = hertz)
  26. Wavelength and frequency
    • Short wave/high freq = high pitched tones
    • Long wave/low freq = low pitched tones
    • Human freq range = 20hz - 20khz
  27. Amplitude
    • Intensity of energy in a given wave of sound
    • Signified by height of sine wave
    • Loudness - subjective interpretation of intensity of a sound
    • Decibel - Logarithmic scale to measure the intensity of sound wave
  28. Human amplitude range
    0dB - 120dB (130dB = pain level)
  29. Resonance
    Different fibers of basilar membrane have different "natural freq"
  30. Basilar membrane
    • Fibers of different lengths, thickness, and tension like strings of a piano
    • Specific parts of basilar membrane vibrate only at specific freq (pitch)
  31. Cochlear hair cells
    Rest on the basilar membrane, contain "sterocilia" which project into the "tectorial membrane"
  32. Perceiving Pitch (freq)
    Location of vibration on the basilar membrane
  33. Perceiving difference in loudness (intensity)
    Amplitude increases, more hair cells of the basilar membrane (with same pitch) are activated
  34. Localizing source of sound
    • Superior olivary nucleus
    • Relative intensity
    • Relative timing
  35. Superior olivary nucleas
    First point where sound from both ears come together
  36. Relative intensity
    The amplitude of sound waves hitting the different ears
  37. Relative timing
    The difference in timing in which a sound reaches both ears
  38. Conduction deafness
    • Disruption in sound vibrations to basilar membrane (ext & mid ear)
    • Caused by:
    • Blocked auditory canal (wax, fluid)
    • Perforated tympanic membrane
    • Otitis media
    • Otosclerosis
  39. Otitis media
    Middle ear infection/inflammation
  40. Otosclerosis
    Hardening of the earbone joints
  41. Sensorineural deafness
    • Disruption anywhere in pathway from hair cells to the auditory cortex
    • Caused by:
    • Loss of hair cells (explosion)
    • Dmg to vestibulochochlear nerve (VIII)
    • Dmg to nuclei/tracts to the cortex
  42. Tinnitus
    • Chronic perception of clicking or ringing
    • Cause by:
    • Sudden blow to the tympanic membrane
    • Gradual deterioration of afferents in chochlear nerve
  43. Menierre's Syndrome
    • Effects both hearing and balance
    • Results in tinnitus, vertigo, and interspersed nausea and vomiting
  44. Linear movement
    • Vestibule
    • Horizontal acceleration
    • Vertical acceleration
  45. Vestibule
    Bony cavity of the inner ear between the chochlea and the semicircular canals
  46. Saccule and Utricle
    Smaller sacs housed within the vestibule
  47. Maculae
    Patch of supporting cells and hair cells along the utricles and saccules
  48. Hair cells
    • Like hair cells of basilar membrane
    • Respond when bent
  49. Otolithic membrane
    Jelly like sheet that abuts the stereocilis of the hair cells
  50. Horizontal acceleration
    • Maculae of UTRICLE is in the horizontal plane
    • Hairs bend when motion in FORWARD/BACKWARD
  51. Vertical Acceleration
    • Maculae of SACCULE  is int he vertical plane
    • Hair bend when motion is UP/DOWN
  52. Angular Movement
    • Semicircular canals
    • Crista ampullaris
    • Change in angular (rotation) acceleration
    • Vestibular nystagmus
    • Vertigo
  53. crista ampullaris
    like maculae, contain hair cells that respond to flow of endolymph in canals
  54. Change in angular (rotational) acceleration
    Movement of the head in non-linear direction is monitored by three canals
  55. Vestibular nystagmus
    Movement of eyes to remain fixed on object when on "merry-go-round"
  56. Vertigo
    False feeling of gravity or motion
  57. Vestibular nuclei
    • Also receive input from eyes and somatic proprioceptors
    • Coordinates information to help control motion of eyes, neck, limbs
  58. Cerebellum
    • Also receives input from eyes and somatic proprioceptors
    • Coordinates information to help regulate head positon, posture, and balance
  59. Problems with Equilibirum
    Dizziness, nausea, imbalance, vomiting
  60. Motion sickness
    Conflict between visual/somatic inputs and action of the vestibular apparatus