Tensor tympani
The
tensor tympani muscle originates from the cartilagenous 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.
Innervation of the muscle is from branches of the mandibular division of the
trigeminal nerve (V3), by way of the
Otic ganglion.
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.
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McGill
