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Cases

Bones Of The Middle Ear

Bones Of The Middle Ear

A healthy 30-year-old male presents to the internal medicine clinic for a routine physical exam. The patient has no specific concerns on this visit. Examination of the left ear with the Wispr Digital Otoscope reveals this image. Can you identify the first two bones of the middle ear?

In this beautiful image of a healthy and normal ear, it is easy to see both the malleus and the incus “through” the eardrum. The bones of the middle ear are the malleus, incus, and stapes. Commonly referred to as the hammer, anvil, and stirrup. These bones are actually on “the other side” of the eardrum; they are located in the middle ear. The eardrum separates the outer ear (the location of the otoscope) from the middle ear.

WiscMed Wispr bones of the middle ear malleus incus

The malleus is attached to the eardrum and communicates the movement of sound-waves from the eardrum to the inner ear via the chain of bones; malleus, incus, and stapes. In many cases, the tympanic membrane (eardrum) is translucent enough that it is possible to identify both the malleus and the incus. It is generally not possible to see the stapes in a normal ear as it is too “deep” in the middle ear. You can see how the relatively long malleus acts as a lever to amplify small movements of the eardrum to the incus. The structure of the middle ear is an example of nature’s elegant biomechanical engineering.

At Wispr University we have an article on normal ear anatomy that can be helpful in understanding what you see during normal otoscopy.