Ears Basics
What are the most common ear diseases or conditions?
The most common ear disease or condition is hearing loss, which is usually present in older patients. The most common thing in a pediatric patient would be an otitis media, which is an infection of the middle ear. Patients with hearing problems commonly come to their primary care physician, be it a pediatrician or internist, and they're usually treated with antibiotics for middle ear infection, or referred for a hearing screen if they have some hearing loss.
How do ears work?
This is a model of the ear and from here you can see the outer ear, which is made up of the oracle. This is the entrance to the ear canal here. If we remove this section here, we can see all of the different parts of the ear. This is the external auditory canal, which makes up the external ear, and this is an example of the tympanic membrane, which is on an angle, actually, and this is the eardrum. You can see that there, and then the bones of the ear, which are attached to the eardrum on the back side. This space here is the middle ear, and that's where middle ear infections occur. This tube here is the Eustachian tube which attaches to the middle ear and helps to regulate the pressure in the ear. So, Otitis Externa or swimmers ear would involve this part of the ear canal up to the eardrum, but it doesn't involve any of the rest of the system. Inflammation and swelling in this area is very painful, and this is what typically a swimmer would get if they maintain water in their ear. Otitis Media is an infection in the middle ear space, behind the eardrum, and is caused by bacteria that either travels up the Eustachian tube or fluid that is collected in the area just because of negative pressure and causes a middle ear infection. The difference between the adult Eustachian tube and a child's is that in the adult, the Eustachian tube is more vertical than in a child. In a child, the Eustachian tube is horizontal, so it allows bacteria and things like milk or food to get into this tube and cause inflammation that extends up into the middle ear.
How does the inner ear work?
The inner ear is comprised of the cochlea and the vestibule, and the vestibule is this bony canal that's filled with fluid, and this is where our balance comes from. The cochlea is the hearing organ. The sound comes down the ear canal, vibrates the eardrum, and is transmitted to the cochlea, which then sends the signal through this nerve to the brain. The vestibule, which is this labyrinth of bony rings, contains fluid that shifts when we move our head from side to side in all directions. It helps us to maintain our balance and know where we are in space. If there's any trauma to the head, this system can be damaged and cause a vertigo or dizziness that the patient experiences. That's pretty much the ear.
What is the "eardrum"?
The eardrum is a membrane that separates the outer ear from the middle ear. It's attached to ossciles, which are bones that vibrate and amplify sound. The eardrum also protects your middle ear from fluid, bacteria or debris getting into the middle ear and causing an infection. The eardrum, in essence, acts like an amplifier.
What are "Eustachian tubes"?
A Eustachian tube is a tube that connects the middle ear to the back of your nose. The Eustachian tube allows the pressure in the middle ear to be regulated so that when you're at high altitudes and the air expands, the air can get out of your middle ear. If the air had nowhere to, go your eardrum would rupture or burst in high altitudes. Or if you were swimming and you dive, you need to get air into your ears and the Eustachian tube allows you to regulate that pressure.
