Tensor tympani muscle

Last revised by Craig Hacking on 16 Feb 2024

The tensor tympani muscle is a small slender muscle in the middle ear that dampens excessive sound vibrations by tensing the tympanic cavity via the malleus.

Gross anatomy

The muscle arises from the superior surface of the cartilaginous part of the Eustachian tube, the greater wing of the sphenoid, and the petrous part of the temporal bone. It passes into the protympanum of the tympanic cavity, covered by the semicanal for the tensor tympani. The muscle has a slender tendon that reflects laterally at the cochleariform process and then inserts into the upper end of the handle of the malleus.

Blood supply

The tensor tympani is supplied by the superior tympanic branch of the middle meningeal artery.

Innervation

The muscle is supplied by the nerve to medial pterygoid, a branch of the mandibular nerve (CNV3), whose cell bodies lie in the motor nucleus of the trigeminal nerve in the pons.

Action

The tensor tympani muscle acts to pull down the handle medially, which in turn tenses the tympanic membrane and therefore reduces the amplitude of its oscillations. This prevents damage to the inner ear from loud sounds. It has no opposing antagonist and elastic recoil restores the status quo as the muscle relaxes.

It has a secondary action on the base of the stapes, tighening the footplate into the oval window.

Related pathology

  • Paralysis of this muscle leads to a hypersensitivity to loud noises (hyperacusis).

  • hypertrophy of the tensor tympani muscle

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Cases and figures

  • Figure 1: number 21
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