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 during this visit. Examination of the left ear with the Wispr Digital Otoscope reveals this image. Can you identify the three bones of the middle ear, the hammer (malleus), anvil (incus), and stirrup (stapes)? In this beautiful image of a healthy and normal ear, it is easy to identify all three bones, technically ossicles, of the middle ear. The middle ear is the space behind the transparent 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 on “the other side” of the eardrum; they are in the middle ear. The eardrum separates the outer ear (the ear canal, open to air) from the middle ear. The eardrum is much like a common musical drum. Most of the surface, the pars tensa, is taught and responds to sound waves with movement. The malleus (hammer) is attached to the eardrum and communicates the movement of 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. Occasionally, you can also identify the stapes as in this example. The stapes is the bone farthest away from the ear drum which is why it is often not possible to see with otoscopy. 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.