OE
What is one of the two purposes of the pinna?
1) collects sound
2) conducts sound
What is 1 of 2 ways the ME matches the impedances of the OE and IE?
1) lever action of ossicles (malleus longer than incus). 2) difference in size between TM and stapes footplate.
The stapes footplate rocks in and out of which structure?
The oval window
what is the nerve that carries vestibular and audiological information? (name or number)
VIII nerve, vestibulocochlear nerve
What is 1 of 2 functions of Eustachian tube?
1) equalizes middle ear pressure
2) provides drainage route IF fluid is present
What is the benefit of the external auditory canal as far as sound perception?
amplifies a small range of high frequencies (2k to 4k Hz) due to resonance of cavity
What causes the stapedius muscle to contract?
high intensity sounds
What fluid is in the Scala tympani?
perilymph fluid
Where do all nerve fibers synapse?
cochlear nucleus
Which structure is made up of the tectorial membrane, inner hair cells, outer hair cells, and basilar membrane?
organ of corti
What is the name for the deep bowl portion of the pinna?
Concha
The manubrium (as seen during otoscopy) is part of what ME structure?
malleus bone
Where are low frequencies processed and coded in the cochlea?
apical turn of cochlea (top of snail shell)
What portion of the brain is tonotopically organized?
The auditory cortex
The VIII nerve is also tonotopically organized. What portion of the nerve carries high frequency sounds?
The outer portion (periphery) of nerve
Which section of the external auditory canal is cartilaginous with cilia and glands that produce cerumen?
Outer (lateral) 1/3. Inner (medial) 2/3 is bony
The stapedius muscle is innervated by which nerve? (give number or name)
The facial nerve (VII)
This structure is attached to the outer hair cells but not the inner hair cells.
tectorial membrane
What is the function of the efferent system?
Inhibits noise so we can focus on speech/other important sounds
All neurons coming from the cochlea travel through what bony structure?
modiolus
What is the name for the part of the pinna you plug your ear with (right outside of EAC)?
Tragus
Which part of the TM has no middle fibrous layer?
pars flaccida
Name one of the two membranes that separate the 3 scales in the cochlea.
Basilar membrane OR Reissner's membrane
What is 1 of the 2 functions of the superior olivary complex (SOC)?
1) localize sound source through timing and loudness level between ears
2) stimulates VII nerve to contract is a loud sound is heard
What vestibular organ is in charge of giving vertical information (straight up and down, not on axis)
Saccule