Neuro test #4.txt

  1. What detects low frequency sounds?
    Interaural time differences
  2. What detects high frequency sounds?
    Interaural intensity differences
  3. What is the K and Na ratios in the endolymph and perilymph?
    • Endolymph: high K, low Na
    • Perilymph: high Na, low K
  4. What are the three parts of the cochlear duct?
    • Scala Media
    • Scala Vestibuli
    • Scala Tympani
  5. What is the fluid difference b/t the three parts of the cochlear duct?
    • Scala Media = Endolymph
    • Scala Tympani and Vestibuli = Perilymph
  6. What windows must be passed through to enter either the scala vestibuli or scala tympani?
    • Vestibuli = Oval Window
    • Tympani = Round Window
  7. What is the name of the bone that makes up the swirly pattern of the cochlea?
  8. Image Upload 1
    vestibular membrane
  9. Image Upload 2
    Tectorial membrane
  10. Image Upload 3
    Spiral ligament
  11. Image Upload 4
    Basilar membrane
  12. Image Upload 5
    Stria Vascularis
  13. What does the Stria Vascularis contain?
  14. What window does the stapes first contact?
    Oval Window
  15. What frequencies are based as the base and apex of the basilar membrane and why?
    • Base: higher frequencies, thinner
    • Apex: lower frequencies, thicker
  16. What creates the material within the tectorial membrane?
    Spiral limbus
  17. What forms the APC (cuticular plate) above the hair cells of the organ of corti?
    Dieter's cells
  18. When do stereocilia de-/hypo-polarize?
    • Depolarize: when bent towards taller cilia
    • Hyperpolarize: when bent towards smaller cilia
  19. What type of fibers synapse on IHCs?
    Type 1 Afferents
  20. What type of fibers synapse on OHCs?
    Type 2 afferents
  21. What is the difference in frequency range between IHCs and OHCs?
    • IHC: Narrow frequency range
    • OHC: Wide frequency range, low frequency
  22. What codes for frequency and intensity?
    • frequency = afferent fiber placement
    • intensity = AP firing rate
  23. Efferent Cochlear innervation
    What do the Lateral Superior Olive (LSO) fibers project to?
    What do the Medial Superior Olive (MSO) fibers project to?
    • LSO: Type I fibers of IHCs
    • MSO: OHCs
  24. What frequencies reach medial and lateral isofrequency columns?
    • Medial: high frequency
    • Lateral:low frequency

    ** They follow the "base to apex rule" with the base being thinner and the apex thicker
  25. What artery supplies the cochlear nuclei in the medulla?
    AICA - specifically the internal labyrinthine artery
Card Set
Neuro test #4.txt
Neuro test #4