Flashcards in W22-L5: Hearing Deck (20):
What is the function of the ossicles?
Matches the impedance of the air to impedance of the fluid within the inner ear
What are the three chambers of the cochlea?
The basilar membrane is wider at the
The basilar membrane is stiffer at the
The base responds to which frequencies?
What is the organ of corti?
Auditory receptors and hair cells sandwiched between basilar membrane and reticular lamina
Deflection of the hair bundle towards tallest stereocilium causes
opening of channels, and depolarization
Displacement of the hair bundle in either directions alters what?
T/F The change in membrane potential due to displacement is symmetric
False, Larger depolarizations than hyperpolarization
Why is potassium important in hearing?
Potassium serves to both depolarize and repolarize the cell
The endolymph has high or low potassium?
What are the two types of hair cells and where do they project to?
Inner hair cells:
95% of nerves that project
to brainstem nuclei
Outer hair cells:
Efferent inputs from the superior olivary complex
What can outer hair cells do during low intensity stimuli to amplify signal?
Change length, Depolarization causes cell contraction
Hyperpolarization causes cell elongation
How do antibiotics cause hearing loss?
Loss of outer hair cells, reduces basilar membrane movement
What is the auditory pathway to the cortex?
Cochlear nucleus, lateral lemniscus, inferior colliculus, MGN, cortex
What is the superior olivary complex?
Lateral and medial superior olives & the
What does the medial superior olive do?
Localization of sound by measuring time delay
What does the lateral superior olive do?
localization of sound by sensing intensity differences
When is the duplex theory relevant?