Middle Ear

The middle ear is the portion of the human auditory system located between the outer and inner ear. It is a small, air-filled cavity that contains three tiny bones called ossicles. These bones, the malleus, incus, and stapes, transmit sound waves from the eardrum to the inner ear.

What is the middle ear and what does it do?

The middle ear has two main functions:

  • To amplify sound waves: The middle ear amplifies sound waves by a factor of about 20. This amplification is necessary because the inner ear is not very sensitive to sound.
  • To match impedances: The middle ear matches the impedance of air to the impedance of the inner ear fluid. This is important because sound waves cannot travel effectively from one medium to another if the impedances are not matched.

What are the 3 parts of the middle ear?

The three parts of the middle ear are:

  • The tympanic membrane (eardrum): The tympanic membrane is a thin, cone-shaped membrane that separates the middle ear from the outer ear. It vibrates in response to sound waves, which causes the ossicles to vibrate.
  • The ossicles: The ossicles are three tiny bones that transmit sound waves from the eardrum to the inner ear. They are named the malleus, incus, and stapes.
  • The Eustachian tube: The Eustachian tube is a small tube that connects the middle ear to the back of the throat. It helps to equalize the pressure in the middle ear with the pressure in the atmosphere.

What is middle ear also called?

The middle ear is also called the tympanic cavity.

What is the function of the middle ear in physiology?

The middle ear plays an important role in physiology by amplifying sound waves and matching impedances. This allows sound waves to travel effectively from the outer ear to the inner ear, where they are converted into electrical signals that are sent to the brain.

Disorders of the Middle Ear

The middle ear is susceptible to a number of disorders, including:

  • Ear infections: Ear infections are the most common disorder of the middle ear. They are caused by bacteria or viruses that infect the Eustachian tube.
  • Barotrauma: Barotrauma is a condition that occurs when the pressure in the middle ear is not equal to the pressure in the atmosphere. This can happen when you travel in an airplane or scuba dive.
  • Ossicular chain disorders: Ossicular chain disorders are problems with the ossicles. They can cause hearing loss.
  • Cholesteatoma: Cholesteatoma is a benign growth that can develop in the middle ear. It can cause hearing loss and other problems.

Treatment for Middle Ear Disorders

The treatment for middle ear disorders depends on the specific disorder. Ear infections are usually treated with antibiotics. Barotrauma can be treated with decongestants and pain relievers. Ossicular chain disorders may require surgery. Cholesteatoma may also require surgery.

If you have any concerns about your hearing, it is important to see an audiologist. The audiologist will be able to assess your hearing and recommend the best treatment for you.