Biology II - Special Senses Unit: Hearing and Equailibrium

receptors for both hearing and equilibrium are found in the ______

internal ear, but they function independently of each other

hearing definition

converting sound waves (vibrations) into impulses the brain can make sense of

equilibrium definition

a sense of balance

how many part is the ear broken into and name them

3

external ear, middle ear, and internal ear

external ear contains the…

pinna, external acoustic meatus, and tympanic membrane (eardrum)

middle ear contains the…

auditory ossicles

name the auditory ossicles and their 2nd name

malleus (hammer), incus (anvil), and stapes (sternup)

internal ear contains the…

vestibule (used for balance), cochlea (means snail), and semicircular canals (used for balance)

how does balance work

the vestibular apparatus is responsible for equilibrium. it consists of the semicircular canals and the vestibule. it is filled with fluid and sensory hair cells that move as the head moves, detecting the direction of the motion.

how do we hear

1. sound creates vibrations in the air

2. the external ear channels vibrations toward the eardrum

3. the eardrum passes the vibrations to the auditory ossicles

4. the auditory ossicles amplify the vibrations and transmit them to the cochlea of the inner ear

5. fluid in the cochlea moves due to the vibrations

6. the basilar membrane, found int he cochlea, vibrates, causing hair cells found in the Organ of Corti to move

7. the moving hair cells trigger an action potential to send to the brain through the auditory nerve

8. The brain interprets the sound