AN SC 310 - 11
Card Set Information
AN SC 310 - 11
AN SC 310
Lecture 11 - The Ear and Hearing
What are the 3 major parts of the ear?
Outer ear - entry of sound waves
Middle ear - amplification of waves
Inner ear - transduction (E to APs)
2. External auditory meatus
3. Tympanic membrane
5. Oval window
6. Round window
8. Vestibular apparatus
9. Eustachian tube
How are sound waves amplified in the ear?
Sound waves strike tympanic membrane
Ossicle movement (1st lvl amplification)
Oval window movement (2nd lvl amplication)
Where does signal transduction for sound occur?
What are the fluids in the cochlea and where are they located?
Perilymph - scala vestibuli, scala tympani
Endolymph - scala media
What is the mechanism of sound transduction?
Stereocilia - connected by protein bridges, mechanical stress moves bridges which opens/closes cation channels
When stereocilia bend, what happens?
Bend toward tall stereocilia = depolarization = APs
Bend toward short stereocilia = hyperpolarization = no APs
What are the 3 semicircular canals and what mvmt do they detect?
Anterior canal - "yes"
Posterior canal - "ear to shoulder"
Lateral canal - "no"
Where are the receptor cells in the semicircular canals located?
What is the name of the tallest stereocilia?
What does the utricle detect?
What does the saccule detect
What are the 2 branches of the vestibulocochlear nerver (cranial nerve VIII)?
Vestibular nerve for equilibrium
Cochlear nerve for hearing