Anatomy of the Ear Medical BY: Kasia Gredzik

The ear is separated into 3 parts: The Inner ear, the middle ear and the outer ear.

Different Look!

Outer Ear The outer ear consists of pinna or auricle, the external auditory canal and the ear drum. The outer ear serves to direct sound vibrations into the ear canal which is carried it to the eardrum. When these sound vibrations reach the eardrum, the eardrum begins to vibrate and we are able to hear.

The Middle Ear The middle ear has three smallest bones in the body. These are the malleus, incus and stapes. These bones send sound through the air filled middle ear. Later, they transfer the sound to the inner ear. Out of the oval window of the cochlea, the last bone is being pushed in and out. The eustachian tube is also found in the middle ear. It serves to equalize pressure between the ear as well as the environment.

The Inner Ear The inner ear, is made up of cochlea and the vestibular system. The snail-shaped cochlea has hair cells that are microscopic cells that connect nerve fibers and enable us to hear. The rocking motion of the stapes in the oval window moves fluid within the cochlea. This causes an action of movement of the hair cells. This shearing action causes the hair cells to send electrical impulses to the auditory nerve. Then these nerves with the information are being carried to the brain by the vestibular system which are interpreted in our brains to a message our minds understand. 


How are people deaf? When someone has a hearing problem or is deaf, this is due to either genetic problem which someone is already born with the defect or it happens over time. Listening to loud noises over and over again, hurts the inside of the ears and ear drums making the ears harmful and slowly loosing the ability to pick up sound vibration.

Types of Hearing Loss Joke? Haha no? Sensorineural Hearing Loss: has to do with a problem in the inner ear. The most common causes of sensorineural hearing loss are: age related changes, noise exposure, inner ear blood circulation issues, various diseases, inner ear fluid disturbances, ototoxic medication, genetics and problems with the hearing nerve. There is no cure for this type of hearing loss and is permanent. Hearing aids are the closest aid that can allow this type of person to hear or cochlear implants may also be an option if the hearing aids do not work.

Conductive Hearing Loss This occurs when sound is not conducted efficiently through the ear canal, eardrum or the tiny bones of the middle ear. Meaning the sounds from outside aren’t being effectively transmitted to the cochlea. This reduces the sound trying to reach into your ear. The reason why it happens is because earwax blocks the ear canal, as does the fluid in the middle ear. Also deformations, in the eardrum or disease of any of the three middle ear bones also contribute to the conductive hear loss. It may be cured only to infection or earwax with medical treatment or surgery to the middle part of the ear is possible as well. It may also be permanent damage when disease overcomes the middle year. If such occurs, only hearing aids or implantable bone-anchored hearing implants are an option.

Mixed Hearing Loss: Central Hearing Loss: Occurs when both sensorineural and conductive hearing loss are present. Solution to those are also the hearing aid or surgery or implants. Central Hearing Loss: This is where the sound is sent through electrical signals to our brain for processing the auditory nerve. Many issues in the central nervous system cause processing of auditory stimulus to breakdown resulting in auditory processing disorder. If someone suffers from this problem may hear but have difficulty understanding the sounds making it almost seam as someone is holding fingers in their ears, or simply having the feeling of ears being full of water.

What is a hearing aid? Dictionary definition: small electronic apparatus that amplifies sound and is worn in or behind the ear to compensate for impaired hearing What the hearing aid does is simply allow someone to hear. By first picking up sound through a tiny microphone, the circuit later takes the sound and deciphers it by already programmed to do the hard work for you. Then the receiver takes the vibrations and delivers in to the inner year, allowing you to hear sounds you never could hear before. This machine is programmed so well that it know when to amplify sound to either make it louder or softer based on the sound you hear around you. All of this is simply powered by a simple battery that fits perfectly in the time ear piece. -picks up sound and amplifies it into your Ear like a microphone so you can hear!

How did Beethoven become deaf? One theory of the cause of Beethoven’s deafness is thought to have been Otosclerosis – the abnormal growth of bone of the inner ear. This is a disease of one of the three main bones of the ear where another bone prevents the ear to work properly and causes hearing loss. Otosclerosis is a disease, which results in new bone formation either in the area of the stapes bone or in the cochlea area It unable the bone to vibrate properly and the sound is then not passed to the inner part of the ear. This results in what is called a conductive hearing loss. The thicker the bone, the greater the impact on the hearing loss. This whole process occurs slowly with time and has a greater affect within time, till it reaches complete deafness. Another theory may have been syphilis, typhus or lead poisining from his heavy medicine he got from doctors. Being a heavy drinker he drank from led cups making him exposed to other diseases that caused a deafness infection. Lastly, some though since his father beat him as a child, injury to the ear may have caused him loss of hearing in the later years of his life.

Ultrasound Images Ultrasound images are produced by the reflection of sound waves against your internal organs and tissues. When a bean of ultrasound pulses pass through the body, the energy is absorbed and the beam is attenuated. These pulses will reflect through the internal body structures, which send echoes to the surface. There they are collected by the transducer which when put together they form images, in black and white. These images display the structures of reflecting structures of the body and produce echoes which form into images that allow us to see and form the structures we need to see.

Anatomy Game! http://www.wisc-online.com/objects/ViewObject.aspx?ID=ap1502

7) Anatomy coloring workbook by Edward Alcamo Ph.D. Bibliography! 1) http://www.wisc-online.com/objects/ViewObject.aspx?ID=ap1502 2) Class Physics Text Book 3) http://webschoolsolutions.com/patts/systems/ear.htm 4) http://www.medkb.com/Uwe/Forum.aspx/tinnitus/917/Is-hearing-loss-the-whole-explanation 5) http://www.healthyhearing.com/content/faqs/Hearing-loss/Types/38062-Different-types-of-hearing 6) http://fookembug.wordpress.com/2007/08/05/how-did-beethoven-become-deaf/ 7) Anatomy coloring workbook by Edward Alcamo Ph.D.