Earache - Description

The ear consists of three parts: the external, middle, and interior ear. The external ear also consists of three parts—the auricle, the auditory canal, and the tympanic membrane. The auricle (pronounced OR-uh-kull) is the outermost part of the ear; the part you can see attached to the sides of your head. The auricle is connected to the interior parts of the ear by means of a narrow opening called the auditory canal. At the end of the auditory canal is the tympanic membrane, or eardrum.

Just beyond the tympanic membrane is the middle ear. The middle ear contains three bones called ossicles (pronounced AH-sih-kulls). These three bones are connected to the inner ear.

The middle ear also contains the eustachian (pronounced you-STAY-shun or you-STAY-shee-un) tube, which connects the middle ear to the pharynx (pronounced FAHR-inks). The pharynx is a passageway behind the nose through which air passes into the lungs. The eustachian tube helps maintain an equal air pressure between the middle ear and the outside world.

Sound waves enter the ear through the auricle and auditory canal. They cause the tympanic membrane to vibrate. That vibration is passed on to the ossicles in the middle ear. Those bones, in turn, pass on the sound vibrations to the inner ear. Once they reach the inner ear, the sound vibrations are sent to the brain by way of the auditory nerve. The brain then translates these vibrations into sounds.

Microorganisms that cause disease can enter the ear in one of two ways. They can enter by way of the auricle and auditory canal, or they can come in through the eustachian tube. In either case, these microorganisms can cause an infection. Infections usually occur in the outer ear or the middle ear. An infection of the outer ear is called otitis externa, and an infection of the middle ear is called otitis media.