Lecture 5- Hearing And Equilibrium Flashcards
When does sound transduction occur?
After the trapped stereocilia of hair cells are deflected by localized membranes of basilar membrane
Inner hair cells
Sensory
Send signals along cochlear branch of vestibulocochlear nerve
Outer hair cells
Efferent
Not sensory
receive signals from brain and alter tension of tectorial membrane, improving hearing sensitivity by amplifying low-amplitude (quiet) vibrations.
Help distinguish between very similar sound frequencies
How is pitch (frequency) perceived?
by hair cells in different positions along the basilar membrane.
How is loudness (volume) perceived?
by greater amplitude vibrations in fluids of the cochlea, causing larger deflections of hair cells and producing larger graded potentials which generate more frequent action potentials.
What is the ability to hear where sound are coming from based on?
the relative intensity and timing of sounds reaching each of your ears.
What does our sense of equlibrium respond to?
head movements
visual information
information from stretch receptors in muscles and tendons
Saccule
Near cochlea
monitor position of the head in space and respond to linear acceleration.
Vestibule
the central cavity of the bony labyrinth. It contains two membranous sacs that house equilibrium receptor regions called maculae.
Utricle
Near semicircular canals
monitor position of the head in space and respond to linear acceleration.
What does each semicircular canal contain?
A semicircular duct
Ampulla
Modular swelling on one end of semicircular duct
Contains equilibrium receptor (crista ampullaris)
Crista ampullaris
Equilibrium receptor
Detects angular or rotational acceleration
Maculae of vestibule
monitor the position of the head in space, and respond to linear acceleration.
Up/down movement
Maculae of utricle
horizontal with vertical hairs.
Forward/backward movements, such as tilting the head
