Auditory System

Question 1

What is the auditory sense organ?

Answer 1

Organ of Corti

Question 2

What is contained in the organ of Corti?

Answer 2

hair cells basilar membrane and tectorial membrane

Question 3

Trace sound from environment to cochlea

Answer 3

1. sound waves
2. tympanic membrane vibrates
3. ossicles vibrate
4. Stapes moves in and out of oval window
5. waves of movement up scala vestibuli within perilymph

Question 4

Trace CNS pathway of auditory input

Answer 4

1. Afferent fibers form cochlear nerve of vestibulocochlear nerve
2. Dorsal and Ventral Cochlear nuclei
   3a. superior olivary complex –> inferior colliculus–> MGN–> A1–> weinerke’s–>angular gyrus–>Broca’s
   3b. inferior colliculus –>MGN

Question 5

Which Broadman’s areas is A1?

Answer 5

41 and 42

Question 6

Wernicke’s area is which broadman’s area?

Answer 6

22

Question 7

Low frequencies go to the _____ and high frequencies go to the _____ of the cochlea

Answer 7

Low frequencies go to the apex

High frequencies go to the base

Question 8

What happens at the superior olivary complex?

Answer 8

localization of sound. Integration of sound and vision

Question 9

Trace the efferent control of auditory perception

Answer 9

A1
MGN
inferior colliculus
OR 
Olivocochlear bundle
Follow CNVIII
Hair cells
Modulates sensitivity to sound

Question 10

The endolymph is found in the _____ and the perilymph is foun in the ______.

Answer 10

Endolymph–cochlear duct

perilympth–cochlea

Question 11

What are the four reasons for hearing loss

Answer 11

1 Conductive-deals with the middle and outer ear

2. Sensorineural- cochlear or auditory nerve; loss of hair cells
3. Central: auditory pathways or centers; brain stem; thalamus cortex
4. Aging-Presbycusis