Question

In the ear of man, the perilymph passes from middle to inner ear through

• A. Foramen ovale
• B. Fenestra ovalis
• C. Fenestra rotundus
• D. Tympanic membrane

Answer 1

Answer: (B)

Fenestra ovalis

The fenestra ovalis connects the tiny bones of the middle ear to the scala vestibuli, which is the upper part of the cochlea. As sound waves vibrate the eardrum, it, in turn, moves the nearest ossicle, the malleus to which it is attached. The malleus then transmits the vibrations, via the incus, to the stapes, and so ultimately to the membrane of the fenestra ovalis. The stapes of the middle ear transmits to the fenestra ovalis (oval window) on the outside of the cochlea, which vibrates the perilymph (fluid) in the scala vestibuli (upper chamber of the cochlea).