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Outer Ear
Description and Function The outer ear is the portion of the ear that sits atop the skull, which is made of flesh and cartilage. It is the visible part which serves to protect the eardrum. It also collects and guides sound waves into the middle ear. Parts and their functions Pinna (ear flap) The ear flap or pinna is the outer portion of the ear. This is the physical portion of the ear that you see on the side of your head, which is used like a satellite dish to collect sound and transmit it inward where it can be translated into the appropriate medium. Meatus (ear canal) This is the ear canal, which extends inward from the outer ear. This 2 cm canal helps to amplify sound as it enters the middle ear so it can be interpreted properly. This area also contains cells which produce ear wax, which helps keep debris out of the middle ear Middle Ear Description and Function The middle ear contains tissue and bone but no skin, and is the area where sound is translated into mechanical energy so it can pass through the body. Most diseases such as ear infections will take hold in the middle ear, though some can also affect the inner ear. It translates sound waves from the outer ear into the form of pressure waves. Compositional parts and their functions Tympanic Membrane (Eardrum) The eardrum, known scientifically as the tympanic membrane Is a thin piece of tissue that is stretched between the outer and middle ear. It is called the drum because sound waves will hit it and cause it to vibrate, which will take the sound from acting as wave energy and translate it to mechanical energy that can travel through the rest of the ear. Malleus (Hammer) The malleus or hammer of the ear is one of the smallest bones in the body. It is connected to the ear drum, and will vibrate as the drum is hit by the sound waves, passing the sound on to the rest of the ear. Incus (Anvil) The anvil bone or the incus sits on top of the hammer, and will collect the vibrations coming from the ear drum, sending them on to the stirrup. Stapes (Stirrup) The stirrup or stapes sits below the anvil, and is the final bone in the inner ear to collect and pass on sound. These sound waves will cause the stirrup to compress, compressing the waves so they can be passed on to the inner ear. Inner Ear (Labyrinth) Description and Function The inner ear is the portion of the ear which is responsible for translating the message and sending it to the brain where it can be interpreted. It is filled with fluid that helps to balance the ear organs and comprise the hearing so it can be passed to the nerves. Compositional parts and their functions Cochlea This is a spiral tube that is covered in a stiff membrane. This membrane is filled with nerve cells, commonly known as ear hairs. These hairs are each designed to pick up on a different type of vibration, which hits in different frequencies. As the nerves begin to vibrate they will turn these frequencies into an electrical pulse which will be sent up to the brain. If the ear is exposed to sound that is too high pitched or too loud, these hair-like nerves can break off, and they will not grow back. This is one of the biggest contributors to hearing loss. Auditory Nerve These nerves receive the electrical impulses generated by the ear and pass this information up to the brain so it can be interpreted. http://www.md-health.com/Parts-Of-The-Ears.html Cochlear Implant
What is a cochlear implant?Ear with cochlear implant. A cochlear implant is a small, complex electronic device that can help to provide a sense of sound to a person who is profoundly deaf or severely hard-of-hearing. The implant consists of an external portion that sits behind the ear and a second portion that is surgically placed under the skin (see figure). An implant has the following parts:
How does a cochlear implant work?A cochlear implant is very different from a hearing aid. Hearing aids amplify sounds so they may be detected by damaged ears. Cochlear implants bypass damaged portions of the ear and directly stimulate the auditory nerve. Signals generated by the implant are sent by way of the auditory nerve to the brain, which recognizes the signals as sound. Hearing through a cochlear implant is different from normal hearing and takes time to learn or relearn. However, it allows many people to recognize warning signals, understand other sounds in the environment, and enjoy a conversation in person or by telephone. http://www.nidcd.nih.gov/health/hearing/pages/coch.aspx |