HEARING PT 1

Question 1

what are the three major parts of the ear

Answer 1

inner, external, middle

Question 2

differentiate between external/middle and inner

Answer 2

external and middle are only involved with hearing and inner is involved in hearing and equilibrium (balance)

Question 3

what are the two structures of the external ear

Answer 3

auricle and external acoustic meatus

Question 4

describe the auricle

Answer 4

pinna; shell-like projection

Question 5

what are the three sections of the auricle

Answer 5

 Helix (rim)
 Lobule (earlobe)
 Funnel sounds waves into auditory canal

Question 6

describe the external acoustic meatus

Answer 6

auditory canal; short tube extending from auricle to eardrum

Question 7

whats the external acoustic meatus lined with

Answer 7

hairs, sebaceous glands, and modified sweat glands (secrete ear wax)

Question 8

whats the tympanic membrane

Answer 8

eardrum; boundary between outer and middle ear

Question 9

what does the tympanic membrane look like

Answer 9

Thin, translucent, connective tissue membrane

Question 10

what makes the tympanic membrane vibrate

Answer 10

sound waves

Question 11

what does the tympanic membrane transfer

Answer 11

sound energy to tiny bones of middle ear
→ sets them vibrating

Question 12

what does the middle ear range from

Answer 12

eardrum to vestibular window

Question 13

what are the three ossicles in the middle ear

Answer 13

malleus, incus, stapes

Question 14

what do the malleus, incus, stapes transmit

Answer 14

vibration of eardrum to oval window

Question 15

what happens after oval window is vibrated

Answer 15

Sets inner ear fluid in motion → Excites hearing receptors

Question 16

describe shape and location of internal ear

Answer 16

Complicated shape (i.e. labyrinth); Lies deep in temporal bone, behind eye socket

Question 17

what are the two division of the internal ear

Answer 17

bony labyrinth and membranous labyrinth

Question 18

whats the bony labyrinth

Answer 18

bony walls that give internal ear cavity-like form

Question 19

whats the membranous labyrinth

Answer 19

membranous sacs/ducts in the bony labyrinth

Question 20

what fluids do the membranous and bony labyrinth contain

Answer 20

perilymph (bony) and endolymph (membranous)

Question 21

what do perilymph and endolymph conduct and respond to

Answer 21

conduct sound vibrations for hearing & respond to mechanical forces from body position changes and acceleration

Question 22

what are the three regions of the internal ear

Answer 22

vestibule, semicircular canals, and cochlea

Question 23

whats the shape of the vestibule

Answer 23

central egg-shaped cavity

Question 24

what does the vestibule contain

Answer 24

saccule (extends to cochlea) and utricle (extends to semicircular canals)

Question 25

what receptors does the vestibule house

Answer 25

equilibrium receptors: respond to gravity pull and head position changes

Question 26

what are the semicircular canals

Answer 26

anterior, posterior, and lateral canals

Question 27

what duct do the semicircular canals contain

Answer 27

semicircular duct (communicates with utricle)

Question 28

what receptors do the semicircular canals house

Answer 28

equilibrium receptors in ampulla (swelling): respond to rotational head movement

Question 29

what does the cochlea extend from, contain, and what receptors does it house

Answer 29

 Extends from vestibule  Contains cochlear duct  Houses receptor organ (spiral organ) for hearing

Question 30

what are the three chambers of the cochlea

Answer 30

1) Scala vestibuli 2) Scala media (cochlear duct) 3) Scala tympani

Question 31

what does each chamber contain

Answer 31

scala vestibuli (perilymph), scala media (enodymph) scala tympani (perilymph)

Question 32

what are the other two structures in cochlea

Answer 32

spiral organ and basilar membrane

Question 33

describe sound

Answer 33

pressure disturbance (alternating areas of high and low pressure) produced by a vibrating object and propagated by molecules of a medium (air)

Question 34

describe hearing

Answer 34

reception of an air sound wave that is converted to a fluid wave that ultimately stimulates mechanosensitive cochlear hair cells that send impulses to the brain for interpretation

Question 35

what are sound waves created from

Answer 35

Alternating areas of high- (compressions) and low- (rarefactions) pressures

Question 36

how does kinetic energy work with sound waves

Answer 36

transferred to air molecules, which then transfer it to other air molecules  Wave energy declines with time and distance

Question 37

whats frequency

Answer 37

pitch; number of waves that pass a point in a given time

Question 38

whats amplitude

Answer 38

intensity/volume; height of wave

Question 39

whats wavelength

Answer 39

distance bw two consecutive crests

Question 40

how are wavelength and frequency related

Answer 40

Shorter wavelength → Higher frequency

Question 41

where does sound enter

Answer 41

external acoustic meatus

Question 42

what happens after sound enters external acoustic meatus

Answer 42

Strikes tympanic membrane  Vibrates at same frequency as sound

Question 43

what happens after sound strikes tympanic membrane

Answer 43

Vibration transferred to auditory ossicles and amplify vibration

Question 44

what happens after vibration is amplified from stapes

Answer 44

Stapes hits oval window, which Vibrates perilymph in bony labyrinth

Question 45

what is the sound we can hear transmitted through

Answer 45

transmitted through cochlear duct to scala tympani

Question 46

what happens after sound is transmitted to scala tympani

Answer 46

Vibrates basilar membrane → Activates hair cells → Action potential sent to brain

Question 47

when do Basilar membrane characteristics changes

Answer 47

across length of basilar membrane

Question 48

what do sounds at audible frequencies do to basilar membrane

Answer 48

vibrate it

Question 49

what happens to sound below audible frequencies

Answer 49

sound returned

Question 50

does Location of basilar membrane vibration and hair cell activation corresponds to specific frequency

Answer 50

yes