Tensor tympani muscle

Tensor Tympani Muscle

Tensor tympani muscle (shown in red)

The Tensor tympani muscle is a small muscle located within the middle ear. It plays a crucial role in dampening the sounds produced by chewing and other loud noises. The muscle is innervated by the medial pterygoid nerve, a branch of the mandibular nerve (V3), which is itself a branch of the trigeminal nerve.

Structure

The tensor tympani muscle originates from the cartilaginous portion of the auditory tube and the greater wing of the sphenoid bone. It inserts into the handle of the malleus, one of the three ossicles in the middle ear. When it contracts, it pulls the handle of the malleus medially, tensing the tympanic membrane and damping vibration in the ear ossicles, thereby reducing the perceived amplitude of sounds.

Function

The primary function of the tensor tympani muscle is to dampen the noise produced by chewing. When the muscle contracts, it pulls the handle of the malleus inward, which in turn pulls the tympanic membrane inward, reducing its ability to vibrate in response to sound waves. This dampens the sound of chewing, which would otherwise be amplified by the resonance of the oral cavity and the nasal cavity.

Clinical significance

Damage to the tensor tympani muscle can result in hyperacusis, a condition characterized by an increased sensitivity to certain frequency and volume ranges of sound. A person with hyperacusis may find normal environmental sounds to be uncomfortably loud or even painful.

See also

• Stapedius muscle
• Middle ear
• Ossicles
• Tympanic membrane