1. Inner Ear
Overview
Cochlea
Organ of Corti
Hair Cells
Basilar Membrane

2. Inner Ear

3. Inner Ear

4. Membranous Labrynth

6. Cochlea Spiral - turban shaped In humans Two and a half turns
35 mm long
5 mm high
9 mm diameter at base but becomes narrower at apical end.

7. Cochlea

8. Cochlea

9. Cochlea (cochlear branch of the VIII nerve)

10. Cochlea (spiral ganglion)

11. Cochlea (modiolus)

12. Cochlea (modiolus)

13. Cochlea (scala vestibuli)

14. Cochlea (scala media)

15. Cochlea (scala tympani)

16. Cochlear Fluids Perilymph - scala vestibuli and scala tympani
Endolymph - scala media
Cortilymph - tunnel of corti in tunnel of corti

17. Cochlear Fluids Function
Deliver nutrients and removes waste from inner ear cells.
Important for transduction process between hydraulic and neural-electric energy.
Acts as a medium to transfer hydraulic vibratory motion that causes hair cell distortion.

18. Cochlear Fluids Perilymph Similar to cerbrospinal fluid
Very high in Sodium (Na)
Very low in Potasium (K)
Overall has a negative ionic charge
Endolymph
Very low in Na
Very high in K
Overall has a positive ionic charge
Cortilymph
Similar to perilymph in chemical composition and ionic charge.
Possibly increases electrical charge in hair cells.

19. Cochlea Cross-Section

20. Cochlea Cross-Section
Scala vestibuli
Scala media
Scala tympani

21. Cochlea Cross-Section (scala vestibuli)

22. Cochlea Cross-Section (scala media)

23. Cochlea Cross-Section (scala tympani)

24. Cochlea Cross-Section (organ of corti)

25. Cochlea Cross-Section (Reissner’s membrane)

26. Cochlea Cross-Section (basilar membrane)

27. Cochlea Cross-Section

28. Cochlea Cross-Section (spiral ligament)

29. Cochlea Cross-Section (spiral lamina)

30. Cochlea Cross-Section

31. Cochlea Cross-Section

32. Summary
You know the drill.