Auditory System

Question 1

What is the function of the thalamus? Where in the diencephalon is it found?

Answer 1

Relays most types of sensory information to neocortex; Dorsal (“roof”)

Question 2

What is the function of the hypothalamus? Which part of the diencephalon is it found in?

Answer 2

Controls autonomic nervous system, controls motivated behaviors, controls many endocrine functions; Ventral (“basement”)

Question 3

What is a part of the telencephalon?

Answer 3

Basal Ganglia, Limbic System, Cerebral Cortex

Question 4

What does the Basal Ganglia control? What structures are in it?

Answer 4

Mediated motor, learning, and “reward” functions; Caudate/Putamen, Nucleus Accumbens

Question 5

What is the limbic system? What is in it?

Answer 5

Mediates emotions, memory, and social behaviors; Medial Prefrontal Cortex, Hippocampus, Amygdala

Question 6

What does the medial prefrontal cortex do?

Answer 6

Social behaviors, “working” memory, and other executive functions

Question 7

What does the hippocampus do?

Answer 7

Learning & memory, stress

Question 8

What does the amygdala do?

Answer 8

Aggressiveness, fear, anxiety, and other emotions

Question 9

What are the lobes of the Cerebral cortex?

Answer 9

Frontal lobe, parietal lobe, temporal lobe, occipital lobe

Question 10

What separates the 2 hemispheres? The frontal and parietal lobe? The temporal, frontal, and parietal lobe?

Answer 10

Longitudinal fissure; Central Fissure, Lateral Fissure

Question 11

How many layers of cell bodies is there in the cerebral cortex?

Answer 11

6

Question 12

What are the 3 properties of sound?

Answer 12

Frequency, Intensity, Complexity

Question 13

What structures are found in the outer ear?

Answer 13

Pinna, Auditory canal, Tympanic Membrane

Question 14

What structures are found in the middle ear?

Answer 14

Ossicles

Question 15

What structures are found in the inner ear?

Answer 15

Oval window, Auditory vestibular nerve, Cochlea

Question 16

What is the function of the attenuation reflex? How does it happen?

Answer 16

Adapt ear to loud sounds & improve speech perception; Onset of loud sound causes tensor tympani and stapedius muscle contraction

Question 17

What is a general function of the ossicles?

Answer 17

Sound Amplification

Question 18

What is the perilymph?

Answer 18

Fluid in scala vestibuli and scala tympani

Question 19

What is the Endolymph?

Answer 19

Fluid in scala media

Question 20

What is the job of the inner hair cells in the cochlea?

Answer 20

Providing auditory information that eventually reaches the brain

Question 21

What is the job of the outer hair cells in the cochlea?

Answer 21

Regulate the “tightness” of the cochlea

Question 22

Where are the stereocilia found in the cochlea? What do they do?

Answer 22

Contained at the top of each hair cell, extending into the tectorial membrane; Movement changes the polarization of hair cells

Question 23

What does the Organ of Corti sit on?

Answer 23

Basement membrane

Question 24

What is the process of transduction of sound pressure?

Answer 24

Sound pressure –> perilymph/endolymph movement –> basilar membrane movement –> stereocilia movement –> hyper or de polarize hair cells –> opening or closing of Ca channels –> incr. or decr. of NT release

Question 25

What does movement of stereocilia towards long sterocilia mean? Short stereocilia?

Answer 25

Movement towards long stereocilia= depolairzation & open channels, short sterocilia= hyper polarization & closed channels

Question 26

What 2 things determine sound intensity?

Answer 26

Firing frequency & Number of spiral ganglion neurons

Question 27

What is place coding?

Answer 27

Different frequencies vibrate basilar membrane at different spots/places.
Low = apex High = Base

Question 28

What is phase-lock coding?

Answer 28

Frequency of sound = frequency of action potentials locked on specific wave phase.

Question 29

What 2 methods do we use to code for sound localization? At which frequencies do we use each?

Answer 29

Interaural time delay: Time taken for sound to reach each ear; Low frequencies
Interaural intensity difference: Intensity difference b/w the ears; Higher Frequencies

Question 30

What is the central auditory pathway?

Answer 30

Hair cells –> Bipolar cells in the Spiral ganglion –> Vestibocochlear Nerve –> Ventral cochlear nucleus (brainstem) –> Superior olive –> Inferior Colliculus –> Thalmus - MGN –> Auditory cortex