Explain briefly the structure and functions of middle ear.
The middle ear is an air-filled chamber on the inner side of eardrum. Its cavity communicates with an air-filled tube called eustachian tube, which maintains a balanced air pressure on either side of the tympanum. The small bones called auditory ossicles are present in the middle ear. The malleus is attached to the ear-drum on one side and to the incus on the other side. The incus intum articulates with the stapes. The stapes is attached to the membrane over an oval-window between the middle ear and the internal ear. Functions: The auditory ossicles transmit the sound- induced vibrations of the ear-drum to the endolymph in the internal ear. The eustachian tube balances and maintains a constant pressure on either side of the ear-drum.
