Definition for Inner Ear
From Biology Forums Dictionary
Vibrations of the innermost ossicle, the stirrup, are transmitted through a flexible membrane, the oval window to the Cochlea of the inner ear.
The cochlea is a tube, about 3.5 cm long, that is coiled like a snail shell and filled with a special fluid called Endolymph. The most dramatic difference in the composition of endolymph from other lymph in the body is its high concentration of potassium (K+) ions.
Running through the cochlea for its entire length is a plate of bone and an inner tube that is also filled with endolymph. These structures divide the outer tube of the cochlea into two separate chambers.
Because liquids are practically incompressible, it is necessary to have some way of relieving the pressures created when the Oval window is pushed in and out. The flexible round window does this by moving in the opposite direction.