Anatomy of the Auditory System

Question 1

1a. What nerve passes posterior to the pars flaccida of the tympanic membrane?

Answer 1

chorda tympani, a branch of CN VII

Question 2

2a. What muscles take origin from the cartilaginous part of hte pharyngotympanic tube (Eustachian tube)?

Answer 2

levator veli palatini & salpingopharyngeus

Question 3

3a. What cranial nerve contributes to parasympathetic fibers to the tympanic plexus on the promontory?

Answer 3

tympanic nerve (a branch of CN IX)

Question 4

4a. What middle ear muscle is innervated by the facial nerve?

Answer 4

stapedius muscle

Question 5

5a. What cochlear component contains endolymph?

Answer 5

scala media (cochlear duct)

Question 6

6a. What term is used to describe the deflection of the basilar membrane induced by sound waves?

Answer 6

traveling wave

Question 7

7a. What cochlear hair cell activates the afferent neurons for the perception of sound?

Answer 7

inner hair cells

Question 8

8a. What cell wall protein contracts to cause outer hair cell amplification of basilar membrane deflections which, in turn, generate distortion product otoacoustic emissions?

Answer 8

prestin

Question 9

9a. What ion channel is lost when the outer hair cell stereociliar are destroyed?

Answer 9

mechanotransduction channel

Question 10

10a. What midbrain nuclei receive cochlear nerve afferents?

Answer 10

inferior colliculus

Question 11

11a. What cochlear nucleus provides input to superior olivary complex?

Answer 11

ventral cochlear nucleus

Question 12

12a. What eponym is used to designate the transverse gyrus that characterizes the primary auditory cortex?

Answer 12

Heschl’s Auditory Cortex or Transverse Gyri of Heschl