Ear Ossicles – Class 11 | Chapter – 20 | Biology Short Notes Series PDF

Ear Ossicles: A flexible chain of three middle bones called ear ossicles is found in the middle ear. There are malleus, incus, and stapes of the three ear ossicles. The malleus, incus, and stapes are also known as the hammer, anvil, and stirrup respectively. The handle of the malleus is connected to the umbo-called central portion of the tympanic membrane. The other end of the malleus is connected by ligaments to the incus. The incus is associated with stapes. Stapes, in particular, is connected to the inner ear’s oval membrane, fenestra ovalis. The ossicles of the ear act as a lever that transmits sound waves from the inner ear to the outside ear. They help to communicate sounds to the fluid-filled labyrinth (cochlea) from the air.


Ear Ossicles

As sound waves vibrate the tympanic membrane (eardrum), in turn, pushes the nearest ossicle, the malleus, to which it is connected. The malleus then transmits the vibrations to the staples, through the incus, and thus ultimately to the membrane of the fenestra ovalis (oval window), the opening of the inner ear vestibule.
In order to improve the transmission and reception of sound, the lever action of the ossicles changes the vibrations and is a form of impedance matching.

Function of Ear Ossicles

  • When sound waves strike the tympanic membrane (eardrum), the vibrations are transmitted through the ossicles- malleus, incus, and stapes, via the oval window to the inner ear.
  • Hence, the ear ossicles help in sound transmission from the external ear to the internal ear.


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By Team Learning Mantras