lect 6 - hearing

Question 1

mechanorecption

Answer 1

detection of vibrations in various media (air, water, ground)

Question 2

amphibian papilla

Answer 2

low frequency
- tuned to the call of specific species

Question 3

basilar papilla

Answer 3

high frequency vibrations trigger hair cells

Question 4

periotic sac

Answer 4

liquid flowing within controls balance

Question 5

stapes (par interna / media)

Answer 5

bone that transmit vibrations into the inner ear

Question 6

amphibian hearing

Answer 6

• good hearing
• multiple calls they give off per spp
• no external ear

Question 7

frog sound production

Answer 7

• lungs compress, mouth + nose close
• air flows over vocal chords + sac, gets pumped back and forth
• vocal sacs can be internal + external, single + paired

Question 8

frog call function

Answer 8

• territorial
• mating
• species recognition
• distress
• warning
• response
• release

Question 9

ultrasound hearing

Answer 9

call at higher frequencies to get around the outside noise
- higher than human range
- don’t travel far

Question 10

tympanum

Answer 10

membrane separating middle + inner ear

Question 11

gardiner’s tree frog

Answer 11

• inner ear has no external connection
• specialized tissue in their mouth (buccal cavity) picks up sound and transmits it straight to the inner ear

Question 12

gecko hearing

Answer 12

• very good hearing
• much better directional awareness (eardrums determine direction before signals reach the brain)
• saccule

Question 13

saccule

Answer 13

coordinates balance in mammals and birds
- also used to enhance hearing in amphibians (detect additional vibrations and feed it to the hind brain)

Question 14

hearing loss in chamelons

Answer 14

• no external tympanum
• middle layer degraded
• biotremors

Question 15

biotremors

Answer 15

gulp pouch produces infrasound vibrations (possible intraspecific communication)

Question 16

tuatara + snake hearing

Answer 16

• no external eardrum
• mandible can pick up vibrations from the ground + transmit straight to the brain
• can’t hear quiet sounds (themselves)

Question 17

marine turtle hearing

Answer 17

• no external eardrum
• bones embedded in soft tissue to reduce air sacs

Question 18

hair cell epithelium

Answer 18

• amphibian papilla
• basilar papilla

Question 19

crocodile ears

Answer 19

• good hearing
• open/closeable flaps over their ear
• can hear quiet noises over most frequencies
• modified eustachian tube connecting mouth + nose + ear
• can replenish hair cells over their lifespan

Question 20

tortoise hearing

Answer 20

greet one another in frequencies lower than human range

Question 21

lateral line system

Answer 21

hair cells on the outside embedded in cupula in aquatic amphibians

Question 22

detecting vibrations in fish

Answer 22

pick up vibrations through motor cells + involuntarily twist the other way

Question 23

apical pits

Answer 23

detect ph, vibrations, thermal signals
- croc skull full of little holes where all nerve endings come out to the pit