The ears are sensitive organs ,collecting the sounds around us, processing them, and sending sound signals to the brain for meaningful interpretation. Our ears also help us to keep our balance. The ear is made up of three distinct sections: the outer ear, the middle ear, and the inner ear .
The outer or external ear:
The external ear consist of two portions, the first being the pinna, the skin covered flabby cartilage of the ear visible on both sides of the head. The basic function of the outer ear or pinna is to protect the eardrum (tympanic membrane). The outer ear also functions to collect sound waves to the eardrum through the ear canal.
The second component of the external ear is the auditory ear canal or meatus. There are modified sweat glands that secrete ear wax in the ear canal. If ear wax is excessive, the ear drum can be damaged or lead to blockage of the transmission of sound.
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The middle ear:
The middle ear refers to the hollowed air-filled bony space (tympanic cavity) in the temporal bone of the skull behind the eardrum. It is just separated from the outer ear by the ear drum. There are three tiny bones (auditory ossicles) in the tympanic cavity that vibrates when exposed to sound waves, namely:
- Malleus – Also known as hammer
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Incus – Also known as anvil
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Stapes – commonly called stirrup
These bones form a chain around the middle ear and extend to the oval window of the inner ear and their main function is to amplify sound.
The middle ear connects to the back of the throat and nose through the Eustachian tube. The Eustachian tube is the auditory openings that we open when we yawn or swallow.
The inner ear:
The inner ear is the most complicated component of the auditory system located into a tiny space of the hardest temporal bone and inaccessible to direct examination or clinical manipulation. The inner ear comprise of three intimately related structures - the cochlea (spiral tube), three semicircular canals and the vestibule (labyrinth).
The cochlea is directly responsible for hearing and contains nerves responsible for converting energy vibrations within the inner ear fluid into nerve impulses which can be transmitted to the brain. While the vestibule (labyrinth) and semicircular canals function to maintain balance or equilibrium.