Answer : The outer ear Pinna Ear canal The Middle Ear Tympanic Membrane The tympanic membrane or eardrum serves as a divider between the outer ear and the middle ear structures. It is gray-pink in color when healthy and consists of three very thin layers of living tissue. The eardrum is very sensitive to sound waves and vibrates back and forth as the sound waves strike it. Middle Ear Cavity The middle ear cavity is located in the mastoid process of the temporal bone. The middle ear cavity is actually an extension of the nasopharynx via the eustachian tube. Eustachian Tube The eustachian tube acts as an air pressure equalizer and ventilates the middle ear. When the air pressure between the outer and middle ear is unequal, the eardrum is forced outward or inward causing discomfort and the ability of the eardrum to transmit sound is reduced. Ossicular Chain The middle ear is connected and transmits sound to the inner ear via the ossicular chain. The ossicular chain amplifies a signal approximately 25 decibels as it transfers signals from the tympanic membrane to the inner ear. THE INNER EAR The inner ear is composed of the sensory organ for hearing—the cochlea, as well as for balance—the vestibular system. The systems are separate, yet both are encased in the same bony capsule and share the same fluid systems. Vestibular or Balance System The balance part of the ear is referred to as the vestibular apparatus. It is composed, in part, of three semicircular canals located within the inner ear. The vestibular system helps to maintain balance, regardless of head position or gravity, in conjunction with eye movement and somatosensory input. The semicircular canals are innervated by the VIIIth cranial nerve. Cochlea The hearing part of the inner ear is the cochlea. The cochlea is spiral-shaped, similar to the shape of a snail. The cochlear duct contains the Basilar membrane upon which lies the Organ of Corti. The Organ of Corti is a sensory organ essential to hearing. It consists of approximately 30,000 finger-like projections of cilia that are arranged in rows. These cilia are referred to as hair cells. Each hair cell is connected to a nerve fiber that relays various impulses to the cochlear branch of the VIIIth cranial nerve or auditory nerve. The apical portion of the basilar membrane (the most curled area of the cochlea) transfers lower frequency impulses. The basal end relays higher frequency impulses. The VIII cranial nerve (VIII C.N.) or auditory C.N. carries the impulses generated from the Organ of Corti to the brainstem. From the brainstem, nerve pathways extend through numerous nuclei to the cerebral cortex in the temporal lobes of the brain. Solution Answer : The outer ear Pinna Ear canal The Middle Ear Tympanic Membrane The tympanic membrane or eardrum serves as a divider between the outer ear and the middle ear structures. It is gray-pink in color when healthy and consists of three very thin layers of living tissue. The eardrum is very se.

1. Answer :
The outer ear
Pinna
Ear canal
The Middle Ear
Tympanic Membrane
The tympanic membrane or eardrum serves as a divider between the outer ear and the middle
ear structures. It is gray-pink in color when healthy and consists of three very thin layers of
living tissue.
The eardrum is very sensitive to sound waves and vibrates back and forth as the sound waves
strike it.
Middle Ear Cavity
The middle ear cavity is located in the mastoid process of the temporal bone. The middle ear
cavity is actually an extension of the nasopharynx via the eustachian tube.
Eustachian Tube
The eustachian tube acts as an air pressure equalizer and ventilates the middle ear. When the air
pressure between the outer and middle ear is unequal, the eardrum is forced outward or inward
causing discomfort and the ability of the eardrum to transmit sound is reduced.
Ossicular Chain
The middle ear is connected and transmits sound to the inner ear via the ossicular chain. The
ossicular chain amplifies a signal approximately 25 decibels as it transfers signals from the
tympanic membrane to the inner ear.
THE INNER EAR
The inner ear is composed of the sensory organ for hearing—the cochlea, as well as for
balance—the vestibular system. The systems are separate, yet both are encased in the same bony
capsule and share the same fluid systems.
Vestibular or Balance System
The balance part of the ear is referred to as the vestibular apparatus. It is composed, in part, of
three semicircular canals located within the inner ear. The vestibular system helps to maintain
balance, regardless of head position or gravity, in conjunction with eye movement and
somatosensory input. The semicircular canals are innervated by the VIIIth cranial nerve.
Cochlea
The hearing part of the inner ear is the cochlea. The cochlea is spiral-shaped, similar to the
shape of a snail.
The cochlear duct contains the Basilar membrane upon which lies the Organ of Corti. The Organ

2. of Corti is a sensory organ essential to hearing. It consists of approximately 30,000 finger-like
projections of cilia that are arranged in rows. These cilia are referred to as hair cells. Each hair
cell is connected to a nerve fiber that relays various impulses to the cochlear branch of the VIIIth
cranial nerve or auditory nerve.
The apical portion of the basilar membrane (the most curled area of the cochlea) transfers lower
frequency impulses. The basal end relays higher frequency impulses.
The VIII cranial nerve (VIII C.N.) or auditory C.N. carries the impulses generated from the
Organ of Corti to the brainstem. From the brainstem, nerve pathways extend through numerous
nuclei to the cerebral cortex in the temporal lobes of the brain.
Solution
Answer :
The outer ear
Pinna
Ear canal
The Middle Ear
Tympanic Membrane
The tympanic membrane or eardrum serves as a divider between the outer ear and the middle
ear structures. It is gray-pink in color when healthy and consists of three very thin layers of
living tissue.
The eardrum is very sensitive to sound waves and vibrates back and forth as the sound waves
strike it.
Middle Ear Cavity
The middle ear cavity is located in the mastoid process of the temporal bone. The middle ear
cavity is actually an extension of the nasopharynx via the eustachian tube.
Eustachian Tube
The eustachian tube acts as an air pressure equalizer and ventilates the middle ear. When the air
pressure between the outer and middle ear is unequal, the eardrum is forced outward or inward
causing discomfort and the ability of the eardrum to transmit sound is reduced.
Ossicular Chain
The middle ear is connected and transmits sound to the inner ear via the ossicular chain. The
ossicular chain amplifies a signal approximately 25 decibels as it transfers signals from the
tympanic membrane to the inner ear.
THE INNER EAR
The inner ear is composed of the sensory organ for hearing—the cochlea, as well as for

3. balance—the vestibular system. The systems are separate, yet both are encased in the same bony
capsule and share the same fluid systems.
Vestibular or Balance System
The balance part of the ear is referred to as the vestibular apparatus. It is composed, in part, of
three semicircular canals located within the inner ear. The vestibular system helps to maintain
balance, regardless of head position or gravity, in conjunction with eye movement and
somatosensory input. The semicircular canals are innervated by the VIIIth cranial nerve.
Cochlea
The hearing part of the inner ear is the cochlea. The cochlea is spiral-shaped, similar to the
shape of a snail.
The cochlear duct contains the Basilar membrane upon which lies the Organ of Corti. The Organ
of Corti is a sensory organ essential to hearing. It consists of approximately 30,000 finger-like
projections of cilia that are arranged in rows. These cilia are referred to as hair cells. Each hair
cell is connected to a nerve fiber that relays various impulses to the cochlear branch of the VIIIth
cranial nerve or auditory nerve.
The apical portion of the basilar membrane (the most curled area of the cochlea) transfers lower
frequency impulses. The basal end relays higher frequency impulses.
The VIII cranial nerve (VIII C.N.) or auditory C.N. carries the impulses generated from the
Organ of Corti to the brainstem. From the brainstem, nerve pathways extend through numerous
nuclei to the cerebral cortex in the temporal lobes of the brain.