Quiz 10- hearing, taste, smell

Question 1

sound is a product of…

Answer 1

vibrational movements of air and water molecules

Question 2

pressure waves are characterized by…

Answer 2

frequency and amplitude

Question 3

pitch

Answer 3

perception of sound frequency

Question 4

loudness

Answer 4

amplitude of sound waves

Question 5

outer ear

Answer 5

pinna funnels sound into the auditory canal
tympanic membrane vibrates in response to sound waves
secondary sensors

Question 6

middle ear

Answer 6

malleus, incus, stapes, oval window, Eustachian tube
vibrated by tympanic membrane

Question 7

inner ear

Answer 7

cochlea, semicircular canals, hair cells, cochlear nerve
primary sensors

Question 8

origin of corti

Answer 8

vestibule and semicircular canal- balance
cochlea- hearing

Question 9

cochlea

Answer 9

scala media (cochlear duct)
scala vestibular- oval window to helicotrema
scala timpani- back to round window
basilar and vestibular membrane

Question 10

auditory mechanics- step 1

Answer 10

sound waves collected by auditory meatus cause vibration of tympanic membrane

Question 11

auditory mechanics- step 2

Answer 11

vibrational energy transmitted to malleus, then incus, then stapes
stapes pushes against oval window

Question 12

auditory mechanics- step 3

Answer 12

vibration of oval window transfers energy to scala vestibule, which causes basilar membrane to vibrate

Question 13

auditory mechanics- step 4

Answer 13

vibration of basilar membrane causes hair cells to bend, opening K+ channels at their base

Question 14

auditory mechanics- step 5

Answer 14

K+ enters hair cell, depolarizing it
K+ leaves by basilar membrane

Question 15

endolymph

Answer 15

fills scala media
has low Na+ and high k+
produced by perilymph

Question 16

perilymph

Answer 16

plasma with high Na+ and low K+

Question 17

tip links

Answer 17

stereocilia are linked by tip links
allow for mechanical stretch to open channels at stereocilia base
composed of cadherin-23 and protocadherin-15

Question 18

tympanic reflex

Answer 18

contraction of tensor tempani and stepedius muscles stiffens tympanic membrane and reduces transmission of sound

Question 19

cochlear hair cells

Answer 19

attached to tectorial membrane
depolarization- tip link tilted left- open ion channels
hyperpolarization-tip link tilted right- closed ion channels

Question 20

Hair cells

Answer 20

have no axonal projections
each stereocilia associated with 1 K+ channel

Question 21

cochlear frequency tuning

Answer 21

standing waves formed at specific frequencies because of localized composition of cochlea

Question 22

cochlear frequency coding

Answer 22

different sound energies focus energy in specific areas of cochlea- activation of these hair cells is interpreted as different frequencies

Question 23

intensity coding

Answer 23

loud sounds characterized by large AP firing rate and which hair cells fire within a given frequency area of cochlea

Question 24

superior olive

Answer 24

interaural intensity differences- lateral superior olive
interaural timing differences- sound reaches one ear before the other- medial superior olive

Question 25

otosclerosis

Answer 25

change in movement of middle ear bones

Question 26

Meniere's disease

Answer 26

inner ear problem cause is unknown age-related hearing loss and dizziness

Question 27

tinnitus

Answer 27

buzzing or hissing caused by anemia, caffeine, drugs, tumors, injuries, hypertension

Question 28

oxotoxic medications

Answer 28

damages sensory cells used in hearing and balance ex. aspirin

Question 29

vestibular system

Answer 29

detection of other types of energy- gravity, acceleration, etc. stereocilia with no tiplink and Na+ mediated depolarization static labyrinth and kinetic labyrinth

Question 30

static labyrinth role

Answer 30

position and acceleration

Question 31

kinetic labyrinth role

Answer 31

movement

Question 32

otoliths

Answer 32

calcium carbonate crystals, provide mass above stereocilia changes sensitivity of hair cells

Question 33

vertigo

Answer 33

balance disorders causing dizziness peripheral or central vertigo

Question 34

peripheral vertigo

Answer 34

sudden onset, intermittent, severe symptoms, dependent on head position, nausea and vomiting

Question 35

central vertigo

Answer 35

gradual onset, constant, mild symptoms, independent of head positions disorders of motor balance

Question 36

olfaction

Answer 36

volatile external chemicals chemoreceptor neurons express specific receptor proteins, within superior nasal cavity

Question 37

olfactory epithelium

Answer 37

about 10^7 bipolar chemoreceptors- replaced every 30 days express GPCRs as stimulus detectors

Question 38

odorant genes

Answer 38

large gene family, primordial function each olfactory neuron expresses 1 odorant gene of small amount an odorant can activate more than one GPCR

Question 39

pheromones

Answer 39

species-specific volatile chemicals sweat and urine denotes social status and reproductive readiness (heat)

Question 40

gustation

Answer 40

taste tongue papillae- 10^4 taste buds less sensitive than olfaction replaced every 10 days

Question 41

human sweet tooth

Answer 41

sweetness is desired by all humans and cultures