Tympanic membrane

Tympanic Membrane

The tympanic membrane, also known as the eardrum, is a thin, cone-shaped membrane that separates the external ear from the middle ear in humans and other tetrapods. Its primary function is to transmit sound from the air to the ossicles inside the middle ear, and then to the oval window in the fluid-filled cochlea.

Anatomy

The tympanic membrane is an obliquely positioned, semi-transparent membrane with a pearly gray color. It is composed of three layers: the outermost layer, which is continuous with the skin of the ear canal; the middle fibrous layer, which is the strongest and contains radially and circularly arranged collagen fibers; and the innermost layer, which is a thin layer of mucosa that is continuous with the lining of the middle ear.

Physiology

The tympanic membrane plays a crucial role in the human auditory system. It vibrates in response to sound waves, with the frequency of vibration corresponding to the pitch of the sound, and the amplitude corresponding to the volume. These vibrations are then transmitted to the ossicles, which amplify and transmit the vibrations to the fluid of the cochlea, triggering a response in the auditory nerve.

Clinical significance

Damage to the tympanic membrane can result in hearing loss. This can occur as a result of trauma, infection, or exposure to loud noise. A ruptured or perforated tympanic membrane is a common condition that can cause pain, hearing loss, and sometimes vertigo. Treatment may involve surgery to repair the membrane, a procedure known as tympanoplasty.

See also

• Otitis media
• Tympanometry
• Tympanostomy tube