The boundary between the middle ear and the inner ear is the
A) eardrum.
B) oval window.
C) cochlea.
D) stirrup.
E) auditory canal.

Question

Quizplus · Accepted Answer

The oval window is the boundary between the middle ear and the inner ear. It separates the air-filled middle ear space from the fluid-filled inner ear space. The vibrations of the eardrum are transferred to the oval window by the three tiny bones of the middle ear (malleus, incus, and stapes), which in turn set the fluid inside the cochlea in motion.

The Boundary Between the Middle Ear and the Inner Ear