Anatomy of Hearing including Ear Structures and Brain Structures
The ear, an organ for hearing and balance, is anatomically divided into three sections: the outer ear, the middle ear, and the inner ear (Henderson). Each section contains many distinct parts that assist in the task of detecting and interpreting sound which is otherwise known as hearing (Henderson). The outer ear is composed of the auricle (pinna) and the external auditory canal (ear canal) (Sisco). The outer ear functions to catch sound waves and funnels them through the ear canal to the middle ear (Inner body). A sound wave, also known as a pressure wave, is a "repeating pattern of high pressure and low pressure regions moving through a medium" (Henderson). The human ear is capable of hearing sound waves 20-20,000 Hz (PATTS). The cartilage skin flap that is most externally visible is known as the pinna (Innerbody). The pinna, besides helping to catch sound waves, provides protection for the ear canal and ear drum (Henderson). When many people think of the ear they think of it as only the pinna. The pinna leads to the external auditory canal (Innerbody). The ear canal narrowing at the middle and widening just before the ear drum, acts as a tunnel for sound waves (CCENT). The external auditory canal is approximately 1 inch long and contains cerumen (ear wax) (Innerbody). Glands within the ear secrete the cerumen, which acts as a protectant against bugs and bacteria (CCENT). Although too much cerumen in the ear canal can block transmission of sound, doctors discourage the manual cleaning of the ear canal (CCENT). The middle ear is an air-filled cavity consisting of the ear drum, three tiny ossicles known as the malleus, incus and stapes, and the eustachian tube (Sisco). The middle ear serves to transmit pressure waves into mechanical vibrations (PATTS). The middle ear is separated from the outer ear by the tympanic membrane (ear drum.)(Hope).The ear drum is about 1/3" in diameter, gray in...
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