Scala media:
- Scala media is a cavity filled with endolymph inside the cochlea.
- It is separated by basilar membrane and reissner membrane.
Roof:
- Roof of scala media is formed by vestibular membrane.
- Outer wall formed by periosteum which lines the bony canals.
Floor:
Floor is formed by membrana basilaris and the outer part of lamina spiralis ossea.
Diagram:
Function:
- Scala media has organ of corti which is the receptor organ for hearing.
- Endolymph is very rich in potassium and has positive potential (80mV).