Tensor tympani

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Tensor tympani
Image:Gray912.png
The right membrana tympani with the hammer and the chorda tympani, viewed from within, from behind, and from above.
Image:Gray914.png
The medial wall and part of the posterior and anterior walls of the right tympanic cavity, lateral view. (Label for "Tensor tympani muscle" is at right, second from bottom.)
Gray's	subject #231 1046
Origin:
Insertion:	handle of the malleus
Blood:
Nerve:	medial pterygoid nerve from the mandibular nerve (V)
Action:

The tensor tympani muscle originates from the cartilaginous wall of the Eustachian tube (also called the auditory tube) and the bony wall surrounding the tube. The muscle inserts onto the handle of the malleus. When tensed, the action of the muscle is to pull the malleus medially, tensing the tympanic membrane, damping vibration in the ear ossicles and thereby reducing the amplitude of sounds: compare the role of the stapedius muscle.

Innervation of the muscle is from branches of the mandibular division of the trigeminal nerve (V3), by way of the Otic ganglion.

[edit] Details from Gray's anatomy

The Tensor tympani, the larger of the two muscles of the tympanic cavity, is contained in the bony canal above the osseous portion of the auditory tube, from which it is separated by the septum canalis musculotubarii.

It arises from the cartilaginous portion of the auditory tube and the adjoining part of the great wing of the sphenoid, as well as from the osseous canal in which it is contained.

Passing backward through the canal, it ends in a slender tendon which enters the tympanic cavity, makes a sharp bend around the extremity of the septum, and is inserted into the manubrium of the malleus, near its root.

It is supplied by a branch of the mandibular nerve through the otic ganglion.

The Tensor tympani draws the tympanic membrane medialward, and thus increases its tension.

[edit] Additional images

Base of skull. Inferior surface.

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.