The Anatomy of the Human Ear (The Middle Ear)

ear-anatomy-middleAnatomy of the Outer Ear
Anatomy of the Inner Ear

The middle ear is a portion of the ear that exist between the eardrum and the oval window. The middle ear sends sound from the outer ear to the inner ear. The middle ear contains three different bones: the hammer (malleus), the anvil (incus) and the stirrups (stapes), the oval window, the round window and the Eustachian tube.

The bones of the middle ear
The eardrum is very thin, measures around 8-10 mm in diameter and is stretched by the small muscles. The compression from sound waves makes the eardrum oscillate.

The vibrations are conveyed deeper into the ear via three bones in the middle ear; the hammer (malleus), the anvil (incus) and the stirrup (stapes). These three bones form a bridge structure, and the last bone, the stirrup, is the last bone to receive sound, is connected to the oval window.

When sound waves are transmitted from the eardrum to the oval window; the middle ear functions to acoustically transform and amplify sound waves before they move on into the inner ear. The pressure of the sound wave on the oval window is nearly 20 times higher than on the eardrum.ear-anatomy-middle2

The pressure grows due to the variance in size between the somewhat large surface of the eardrum and the smaller surface of the oral window. An example of this same principle occurs, when a person, wearing a shoe with a sharp stiletto heel, steps on your foot. The small surface of the heel will cause more pressure and pain than a flat shoe with a large surface.

ear-anatomy-middle3The round window
The round window is in the middle ear, vibrating in opposite phase to vibrations that enter inner ear via the oval window. Through this method, fluid in the cochlea to move.

The Eustachian tube
The Eustachian tube is also found in the middle ear and connects the ear with the rearmost part of the plate. The Eustachian tube’s purpose is to equalize the air pressure on both sides of the eardrum. This prevents pressure from building up in the ear. When you swallow, the Eustachian tube opens, thus equalizing the pressure inside and outside the ear.

ear-anatomy-middle5In the majority of cases, pressure is equalized automatically, but if this does not occur, it can be brought about may making an energetic swallowing action. The swallowing action will force the tube connecting the palate with the ear to opened, thus equalizing the pressure.ear-anatomy-middle4

Additional pressure can build up in situations where the inside of the eardrum is different from that on the outside of the eardrum. If the pressure is not equalized, pressure will build up on the eardrum, preventing it from vibrating sound correctly. The restricted vibration results in a minor reduction in hearing ability, which can create a muffling sensation. A significant difference in pressure will cause discomfort and even slight pain, the built-up pressure in the ear will frequently occur in circumstances where the pressure often changes, for example when flying on an airplane or driving through mountainous areas.

Signs of an Ear Infection

Anatomy of the Outer Ear
Anatomy of the Inner Ear



Health Life Media Team