Chapter 8 The Auditory System

Question 1

Function of Auditory System

Answer 1

-Mediates hearing
-Allows us to understand speech
-Consists of multiple parallel pathways that engage multiple cortical regions (via directly or via complex corticocortical networks)

Question 2

Auditory System Receptors

Answer 2

-Hair cells
-Each have bundle of hair like stereocilia on apical surface
-Each receptor is sensitive to a limited frequency range of sounds

Question 3

Order of Neurons in Auditory Pathways

Answer 3

1st: Hair cells to cochlear nuclei
2nd: Cochlear nuclei to superior olivary complex
3rd: Superior olivary complex to inferior colliculus
4th: Inferior colliculus to medial geniculate nucleus
5th: MGN to primary auditory cortex

Question 4

Auditory Pathways Decussation

Answer 4

-Decussations and commissures at multiple levels so sounds from one ear can be processed to both

Question 5

Dorsal Cochlear Nuclei

Answer 5

-Role in identifying sound source elevation and identifying complex spectral characteristics of sound

Question 6

Ventral Cochlear Nuclei

Answer 6

-Horizontal localization of sounds

Question 7

Where do the “What” and “Where” pathways originate and project?

Answer 7

-Originate from the primary auditory cortex
-Project to secondary auditory cortex, then to higher order areas in temporal lobe

Question 8

Where specifically does the “What” pathway project to

Answer 8

-Orbital-frontal cortex -Ventral premotor cortex

Question 9

Where specifically does the “Where” pathway project to

Answer 9

-Posterior-parietal cortex
-Dorsolateral prefrontal
-Premotor cortex
(also projects from temporal lobe to frontal lobe through arcuate fasciculus)

Question 10

Arcuate Fasciculus

Answer 10

-C-shaped structure
-Interconnects caudal superior temporal cortex with the inferior parietal lobule

Question 11

Broca’s and Wernicke’s Area

Answer 11

-Broca’s Area: Speech Production
-Wernicke’s Area: Understanding speech