Auditory

Question 1

Human speech intensity

Answer 1

65dB

Question 2

Frequency

Answer 2

10-20,000Hz

Question 3

What occurs in the middle ear?

Answer 3

air pressure waves are converted to mechanical energy via tympanic membrane and ossicles

Question 4

Tube responsible for connecting ear with nasopharynx

Answer 4

Eustachian tube (site of infections known as otitis media)

Question 5

Function of tensor tympani

Answer 5

pressure regulator; stretched in loud environment (innervated by CN 5)

Question 6

Function of stapedius

Answer 6

purely reflexive, contracts to dampen very loud sounds by pulling on neck of stapes to control amplitude of sound (innervated by 7)

Question 7

What can you see past the tympanic membrane?

Answer 7

CN 7 and malleus

Question 8

Two components of inner ear

Answer 8

cochlea and vestibular apparatus (semicircular canals, etc)

Question 9

Perilymph

Answer 9

fluid in bony labyrinth

Question 10

Endolymph

Answer 10

fluid in membranous labyrinth; has very little protein and very low sodium concentration; carries a charge of +80mV

Question 11

Three routs of pressure wave transduction to inner ear

Answer 11

1) Air (poor)
2) Osseous (vibration of bone in skull - mastoid and petrous - still poor) called bone conduction
3) Ossicular (EFFICIENT) directly couples inner and outer ear; called air conduction

Question 12

What makes up the cochlea?

Answer 12

scala vestibuli (connected to oval window), helicotrema (apex), and scala tympani (connected to round window)

Question 13

What secretes endolymph?

Answer 13

stria vascularis

Question 14

What is cochlea contained within?

Answer 14

the modiolus

Question 15

What structure is between the scala vestibuli and scala tympani?

Answer 15

Cochlear duct (scala media)
Reisner’s membrane separates it from scala vestibuli from above
Basilar membrane separates it from scala tympani from below

Question 16

Where is the basilar membrane the widest?

Answer 16

helicotrema (the apex)

low pitches heard here

Question 17

Where is the basilar membrane the stiffest?

Answer 17

at the base

highest pitches are heard here

Question 18

What is the Organ of Corti?

Answer 18

site of transduction of pressure waves on the hair cells - sits on the basilar membrane

Question 19

Function of outer hair cells

Answer 19

• displacement sensitive
• used to modulate the tectorial membrane (ONLY receptors directly modified by CNS and can tune themselves to respond by becoming longer and shorter)
• 10 hair cells per bipolar cell

Question 20

Function of inner hair cells

Answer 20

• velocity sensitive
• short and stiff and used to detect sound; NOT modified by CNS
• each are innervated by 10 bipolar cells

Question 21

What does bending of the hair cells TOWARDS kinocilium do?

Answer 21

depolarizes and opens K+ ion channels

Question 22

What does bending of hair cells AWAY from kinocilium do?

Answer 22

hyperpolarizes and closes K+ channels decreasing release of neurotransmitter

Question 23

What is the “Tonotopic Map?”

Answer 23

map of basilar membrane where different frequencies resonate along it. Info is carried to CNS (like cochlear nuclei, inferior colliculus, medial geniculate, cerebral cortex, and Heschel’s gyrus)

Question 24

Where is hearing bilateral?

Answer 24

past cochlear nuclei

Question 25

What is phase locking?

Answer 25

what is done to achieve temporal resolution (first pushes when sound starts then pulls back)

Question 26

What is the interaural difference?

Answer 26

the delay between when a sound is heard in one ear and the other

Question 27

Name of the auditory area of the cortex?

Answer 27

Heschl's gyrus

Question 28

Stroke in Wernicke's area

Answer 28

failure to comprehend auditory signals (either visual or spoken) Word salad

Question 29

Stroked in Broca's area

Answer 29

failure to produce speech (loss of input to motor cortex) | Broca = boca problems