Last week, we started sharing a detailed series on the physiology of the ear. First, there was an in depth article about the outer ear. This week, we are going deeper into the ear as we share about the physiology of the middle ear.
The outer ear in review:
As we know, the ear is the organ of hearing and balance. The parts of the ear include the outer ear, also called the external ear. We discussed the pinna which is the outer ear that we can see without using any devices.
The pinna is also referred to as the auricle as well. Next, we dove deeper into the ear. The next section of the ear is the ear canal. The ear canal is medically named the external auditory canal.
It is also sometimes called the external auditory tube. This tube connects the outer ear to the middle ear. Next up comes the tympanic membrane.
Medical professionals may call it the tympanic membrane but you may mostly hear it called the eardrum. This part of the ear divides the outer, or external, ear from the middle ear.
The middle ear:
The middle ear is medically named the tympanic cavity.The tympanic cavity is made of the ossicles and the eustachian tube. An eardrum is actually quite thin. It is only eight to ten millimeters in diameter. The eardrum is stretched by small muscles.
Sound waves make the eardrum vibrate. The vibrations travel from the eardrum deeper into the ear to the middle ear. The three small bones that make up the ossicles are called the hammer, anvil, and stirrup.
However, their real names are the malleus, incus, and stapes. Together, these three small bones form a bridge-like structure. The last bone that receives sounds, which is referred to as the stirrup, connects to a small oval window.
Once the sound waves make their way from the eardrum to the oval window, the middle ear functions as an acoustic transformer. The middle ear amplifies the sound waves before they move into the inner ear. The pressure of the sounds waves on the oval window are very strong.
Sometimes they are twenty times higher than on the eardrum. The difference in pressure is due to the difference in size of the eardrum and the oval window. The pressure is increased due to the large difference between the surface of the eardrum and the surface size of the oval window.
The round window in the middle ear vibrates in opposite phase to the vibrations entering the inner ear through the oval window we previously mentioned. Meanwhile, it allows fluid inside of the cochlea to move. Now, the sound moves into the eustachian tube.
As for this part of the ear, we have a whole blog just on this important part of the ear. Check out that article in the link above if you have not already. This will inform you sufficiently on the purpose and function of the eustachian tube.
Seek immediate medical attention from ENT doctors in Orlando:
Thank you for stopping by and reading today’s blog. Remember to come back and read more about your hearing health, physiology of the ear, and how our ENT doctors in Orlando treat patients for ear pain or hearing loss. Make an appointment today to be seen soon!
Staff Writer
