Ch. 11 The Ears And Hearing

Front 1

external ear

Back 1

gathers sound waves and conduct them to the typanic membrane.

Front 2

tympanic membrane

Back 2

sep. the ext. and middle ears

Front 3

middle ear

Back 3

What part of the ear does amplification of sound waves in preparation for the transmission of those from air to fluid environment.

Front 4

middle ear

Back 4

malleus
incus
stapes

Front 5

ossicles

Back 5

extend from the tympanic membrane to a thin membrane (oval window).

Front 6

oval window

Back 6

conn. btwn. the middle and inner ears.

Front 7

round window

Back 7

conn. middle and inner ears

Front 8

eustachian tube

Back 8

conn. the middle ear w/ the pharynx
helps maintain normal pressure in the middle ear.

Front 9

decibels

Back 9

amplitude of a sound is most conveniently expressed in logarithmic units called ________.

Front 10

hertz

Back 10

The frequency of sound waves is measured as the number of waves per second, or _______.

Front 11

sound waves
amplitude

Back 11

The oscillations occur at the same frequency as that of the ______ ______, and w/ an amplitude proportional to the _________ of the sound waves.

Front 12

malleus
tympanic
oscillate

Back 12

Because the ________, the first of the small ossicles, is connected to the _________ membrane, oscillations of the tympanic membrane cause the malleus to ___________ at the same frequency and w/an amplitude reflecting that of the tympanic membrane's vibrations.

Front 13

oval window
Amplification

Back 13

The stapes overlies the ____ _______ to the fluid filled cochlea, such that oscillations of the stapes generates waves in the fluid of the cochlea. _____________ is required during this process.

Front 14

cochlea

Back 14

The organ in which sound transduction occurs.

looks like a spiral shell on outside

Front 15

helicotrema

Back 15

point at the end of the spiral

Front 16

cochlea

Back 16

vestibular membrane & basilar membrane seps. it into:

scala vestribuli (vestibular duct)
scala tympani (duct)
scala media (cochlear duct)

Front 17

helicotrema

Back 17

The vistibular and basilar membranes join at the ___________; thus there is an opening btwn the scala vestibuli and scala tympani at the ____________.

Front 18

perilymph

Back 18

What is the fluid in the scala vestibuli and scala tympani called?
(similar to cerebralspinal fluid)

Front 19

endolymph

Back 19

What is the fluid inside the scala media called?
(similar to intracellular fluid)
(high conc. of K+ and low conc. of Na+)

Front 20

oval and round windows

Back 20

What separates the cochlea from the middle ear?

Front 21

stapes
oval window
round window

Back 21

When the _______ vibrates in response to sound waves, it causes vibration of the ____ _______, producing waves in the perilymph of the scala vestibuli. The waves travel through the scala tympani, where they cause motion of the _______ _______.

Front 22

organ of corti

Back 22

hair cells
tectorial membrane
sterocilia

Front 23

stereocilia

Back 23

The anatomy of the organ of Corti is such that sound waves cause mechanical bending of the ___________, which causes receptor potentials in the hair cells.

Front 24

open
close

Back 24

Depending on the direction the stereocilia bend, K+ channels in the hair cells either _____ or ______.

Front 25

depolarize

Back 25

The opening of K+ channels results in K+ diffusing into the hair cell, causing ____________.

Front 26

hyperpolarization

Back 26

Closing of the K+ channels prevents K+ from diffusing into the hair cell, causing _______________.

Front 27

bending of stereocilia

Back 27

What causes the K+ channels to open or close?

Front 28

partially depolarized

Back 28

When the stereocilium are sticking straight up (no sound waves present), what happens to the hair cell?

it depolarizes
it hyperpolarizes
it partially depolarizes

Front 29

it depolarizes

Back 29

When the stereocilium are bent towards the taller stereocillium, what happens to the hair cell?

it depolarizes
it hyperpolarizes
it partially depolarizes

Front 30

it hyperpolarizes

Back 30

When the stereocilium are bent away from the largest stereocillium, what happens to the hair cell?

it depolarizes
it hyperpolarizes
it partially depolarizes

Front 31

bony labyrinth

Back 31

The vesitibular apparratus is located in cavities of the temporal bones called the ____ ________.

Front 32

membranous labyrinth

Back 32

The vestibular apparatus consists of membrane-bound structures w/in bony labyrinth, these structures are also called ___________ __________.

Front 33

vestibular apparatus

Back 33

semicircular canals
utricle
saccule

Front 34

semicircular canals

Back 34

detect rotational acceleration
oriented in planes that are perpendicular to each other

Front 35

ant. canal (semicircular canals)

Back 35

detects rotation of the head up and down, and when nodding "yes"

Front 36

post. canal (semicircular canals)

Back 36

detects rotation of the head up and down to the side, as in moving the ear to the shoulder.

Front 37

lateral canals (semicircular canals)

Back 37

detects rotation of the head from side to side, as when shaking the head to indicate "no"

Front 38

utricle and saccule

Back 38

detect linear acceleration

Front 39

utricle

Back 39

detects accleration forward and backward

Front 40

saccule

Back 40

detects acceleration up or down

Front 41

ampulla

Back 41

have receptor cells for equilibrium
a hair cell
an enlarged area at the base of each semicircular canal

Front 42

cupula

Back 42

in ampulla
a gelatinous area separated from the endolymph by a membrane

Front 43

kinocilium

Back 43

one of the stereocilia that is much larger that the others in the cupula.

Front 44

endolymph

Back 44

When the constant rotation suddenly stops, the head and bony labyrinth stop as well, but the ___________ keeps moving for a time.

Front 45

otoliths

Back 45

small calcium crystals that add mass to the gelatinous material