Module 22 - Special Senses: Hearing and Balance Flashcards
define sound
sound – the interpretation
of vibrations
define volume
Volume – wave amplitude
define pitch
Pitch – wave frequency
what collects sound in the external ear
auricle
what is the anatomical word for ear drum
tympanic membrane
what are the 3 components of the auditory ossicles of the middle ear
malleus, incus, stapes
what are the two components of the inner ear that separate the middle and inner ear
oval and round windows
what connects the hear to the throat
auditory tube
what are the 3 main parts of the inner ear
cochlea - hearing
vestibule - static balance
semicircular canals - dynamic balance
the endolymph has more what? Na or K
more K, less Na
the perilymph has more what? Na or K
more Na, less K
what’s on the outside of the inner ear, the bony labyrinth or the membranous labyrinth
bony labyrinth is on the outside
what is the end of the tube in inner ear called
helicotrema
where are the hair cells in the cochlea
in the spiral organ
what is attached to the round window in the cochlea
scala tympani
what is attached to the oval window in the cochlea
scala vestibuli
where are the specialized cells in the cochlea
in the basilar membrane
what makes up the spiral organ in the cochlear duct
supporting cells, outer hair cells, inner hair cells
what is stereocilia
Hair cells have bundles of microvilli at their
apex called stereocilia
what is tip-link
tip-link – connects tip of each stereocilium in a hair bundle to the side of the next longer stereocilium
Explain depolarization of inner ear
- Unstimulated – gating
spring relaxed - Stereocilia bend toward
taller stereocilia – gating
spring stretches - K+ enters the cell
lower pitch goes through blank while higher goes through blank
helicotrema, oval window
describe the effect of sound waves on the cochlear structures
- Sound waves enter external auditory canal and strike the tympanic
membrane causing it to vibrate - Vibration is transferred to the middle ear
- Foot plate of the stapes vibrates in the oval window
- Vibration of the foot plate causes the perilymph in the scala vestibuli to
vibrate. - Vibration of the perilymph causes the vestibular membrane to vibrate
vibrations in the endolymph displacement of the basilar membrane
Movement of the basilar membrane is detected in the hair cells. - Vibrations from the perilymph in the scala vestibuli and vibrations in the
basilar membrane are transferred to the perilymph of the scala tympani. - Vibrations in the perilymph of the scala tympani are transferred to the
round window
whats the neural pathway of hearing
the utricle deals with blank motion while the saccule deals with blank motion
horizontal, vertical
explain static equilibrium
the blank dictates head direction in dynamic equilibrium
cupula
the cupula moves with or against direction of head?
opposite direction
stimulation in dynamic equilibrium stops when…
stimulation stops when fluid in canals catches up with
the cupula
what happens when the movement of the head stops in dynamic equilibrium
movement of the head ceases – endolymph continues
to move in the same direction as the head was – cupula
will also
explain neural pathway of balance
