how human ear enables us to produce sound waves and how we actually interpret them.I got a grade hope students will be clarifying their basic concepts related to anatomy of the human ear.

1. Topic:-Anatomy of the Ear
Presented to:-Dr.Kashef Shaban
Presented By:-Fatima Hussain
ID:-BAF1702031
Course:-Human Anatomy-1
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2. 2
• The External Ear
• Consists of: –
• Auricle (pinna)
• Made of elastic cartilage
• Helix (rim)
• Lobule (ear lobe)
• External auditory canal
• Lies within temporal bone & connects to ear drum (tympanic membrane)
• Contains ceruminous glands which secrete ear wax
• Tympanic membrane
• Epithelial & simple cuboidal
• Changes acoustic energy into mechanical energy
• Perforated eardrum = tear

3. The Middle Ear
Auditory Ossicles (smallest bones in body)
.Malleus
Attaches to ear drum
 Articulates with incus
• Incus
Articulates with stapes
• Stapes (stirrup)
Footplate of stapes fits into oval window
• Opening to Eustachian tube
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4. • Protection by Two Tiny Muscles:-
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Tensor Tympani
Attaches to Malleus to
increase tension on ear
drum.
Stapedius
Smallest skeletal muscle
prevent damage to inner
ear.
Dampens large vibrations
of stapes to protect oval
window.

5. • Auditory Tube (Eustachian tube)
 Is a route for pathogens to travel from nose and
throat to ear causing Otitis Media
 During swallowing and yawning it opens to equal
pressure in middle ear.
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6. The Inner Ear (Labyrinth)
• Bony labyrinth –
• Contains perilymph
• Semicircular canals
 Anterior, posterior, and lateral
 Lie right angles to each other
• Vestibule
• Oval portion
• Cochlea
• Looks like a snail
• Converts mechanical energy into electrical energy
• Membranous labyrinth
• Contains endolymph.
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7. • The Cochlea:-
• Divided into 3 channels –
• Cochlear duct (scala media) -Contains the
Organ of Corti .
• Scala vestibuli -Ends at the oval window
• Scala tympani-contains pillar cells and
supporting cells.
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8. Organ of Corti
• Organ of Corti. The organ of Corti is the sensitive element in the
inner ear and can be thought of as the body's microphone.
• It is situated on the basilar membrane in one of the three
compartments of the Cochlea.
• It contains four rows of hair cells which protrude from its
surface.
• The end organ of hearing
• Contains stereocilia & receptor hair cells
• Tectorial and Basilar Membranes
• Cochlear fluids
• Fluid movement causes deflection of
nerve endings
• Nerve impulses (electrical energy)
are generated and sent to the brain.
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9. Summary of How We Hear
• Acoustic energy, in the form of sound waves, is
channeled into the ear canal by the pinna.
• Sound waves hit the tympanic membrane and cause
it to vibrate, like a drum, changing it into mechanical
energy.
• The malleus, which is attached to the tympanic
membrane, starts the ossicles into motion.
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10. • The stapes moves in and out of the oval window of
the cochlea creating a fluid motion, or hydraulic
energy.
• The fluid movement causes membranes in the Organ
of Corti to shear against the hair cells.
• This creates an electrical signal which is sent up the
Auditory Nerve (cochlear nerve) to the brain.
• The brain interprets it as sound!
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11. Conclusion
 The ear is a very complicated device.
 hearing is a delicate and complex phenomenon.
 The healthy human ear can hear
frequencies ranging from 20Hz to 20,000 Hz.
 The average person can hear sounds
down to about 0 dB, the level of
rustling leaves.
 Some people with very good hearing
can hear sounds down to -15 db.
 This should put into perspective
the common saying that the ears are the
ultimate judge in music production..
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12. • Ears are always working. Your ears never stop
hearing even while you're asleep.
• Ears help with balance. Your ears are essential for
you to maintain your balance.
• Ears self-clean.
• Ears have the smallest bones in the body. ...
• Earlobes are constantly growing.
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13. References
• https://audiologicalservices.net/audiology-news-
lufkin-tx/5-amazing-facts-about-ears
• http://www.pamf.org/hearinghealth/facts/hearing_f
acts.html
• https://emedicine.medscape.com/article/1948907-
overview
• https://www.healthline.com/human-body-
maps/ear#1
• https://www.britannica.com/science/ear/The-
physiology-of-hearing
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14. The End
Thank you….
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