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The ear provides humans with a remarkable range of hearing. It is divided up into three
regions, the inner ear, the middle ear, and the outer ear. The outer and middle ear
are responsible for hearing, while the inner ear regulates equilibrium, and balance.
 The outer ear
is composed of the ear canal, the external auditory canal, and the pinna. The pinna is a
cartilage structure resting on opposite sides of the head. The purpose of the pinna is to
funnel sound waves into the external auditory chamber. The external auditory chamber is a
small, narrow chamber that is carved into the temporal bone of the skull. Within this
chamber are glands that regulate the secretion of cerium, commonly known as earwax. When
sound enters the external auditory chamber it is reflected to the tympanic membrane, known
as the eardrum, causing it to vibrate.
The
middle ear, also known as the tympanic cavity, is a small air filled cavity within the
temporal bone. It houses the auditory tube, which runs from the ear, to the throat. The
auditory tube regulates the pressure of the ear, and has adapted to accommodate any
changes in the pressure of the ear. The middle ear houses three of the smallest bones in
the body, the hammer, the anvil, and the stirrup. When the eardrum vibrates it transfers
this vibration to the hammer, the anvil, the stirrup, and finally presses against the oval
window inside the inner ear.
The
inner ear is also known as the osseous labyrinth. It may be divided into three regions,
the cochlea, the vestibule, and the semicircular canals. These regions are responsible for
transforming the vibrations to nerve impulses that can be sent to the brain. The inner ear
holds the perilymph. Inside of which is the membranous labyrinth. These structures contain
a number of sacs follow the shape of the bony labyrinth. These two structures are
responsible for equilibrium, or balance. In the sacs of the perilymph rest receptors known
as maculae. The maculae are responsible for balance. When the sacs of the ear are turned
to a new position, the maculae turn. When the maculae turn, the gel in the inner ear is
pulled, resulting in an impulse to the vestibular nerve, which notifies the brain of the
change of position

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