Parts and Functions of the Ear
Dec 22, 2015
Parts and Functions of the Ear
What is sound?
• Sound is the vibration of air molecules. Sound waves refer to the “ripples” created as the sound vibrations move out from the source.
• 1. To send sound waves to the middle ear.
• 2. To keep the ear clean of debris.
a) cilia: hair
b) cerumen: ear wax
The tympanic membrane has two functions:1. Seals off the middle ear.
2. Vibrates the ossicles (ear bones).
The ossiclesthe three smallest bones in the
body• h. Malleus
(hammer)• i. Incus
(anvil)• j. Stapes
(stirrup)• (MIS)
Ligaments connect the malleus directly to the back of the tympanic membrane.
The stapes taps the cochlea to transmit sound vibrations to the inner ear.
e. Eustachian tube• Has two functions:• Equalizes air pressure in the
middle ear• Drains the middle ear
b. semicircular canal c. cochlea
• The semicircular canals maintain balance.
• The cochlea changes sound vibrations to nerve impulses.
These nerve endings are triggered
by vibrations sent through the liquid-filled cochlea. As the nerves exit the cochlea they combine together to become the auditory nerve.