topic.7.the.senses.powerpoint.7.1.hearing Flashcards
Hearing relies on ____ in the ear that respond to the
sensory hair cells; vibrations of sound waves
Vibrations produces____
soundwaves,
Exists as variations of pressure in air aka vibrating air
A loud sound will effect what part of the wave?
wave amplitude
A bigger amplitude results in a
louder sound
The pitch of a sound is related to ___, which is related to the ___ of a wave.
frequency; wavelength
higher the frequency, the ___ wavelength
shorter
draw the auditory system
-auditory canal-eardrum-malleus-incas-stapes-oval window-round window-cochlea-auditory nerve Eustachian tube at bottom
Eardrum:
also called tympanic membrane
Malleus:
hammer
incus:
anvil
stapes:
stirrup (also known as ossicles)
Eustachian tube:
leads to the throat. When we swallow, tube opens, air flows in or out of the ear to equalize pressure.
cochlea:
a spiraled, hollow, conical chamber of bone
Scala vestibuli:
vestibular canal (perilymph: rich in Na+); superior cochlear duct
Scala media:
cochlear duct (endolymph: rich in K+)
Scala tympani:
tympanic canal (perilymph: rich in Na+); inferior scala media
Write in spatial order scala media, scale tympani and scale vestibuli
Vestibular canal
cochlear duct
tympanic duct
in the cochlea duct, you can find sterocilia of hair cell in between what two things?
tectorial membrane and basilar membrane
basilar membrane
-forms part of the floor of the cochlear duct
-Anchors the sensory hair cells in the Organ of Corti
-Vibrates in response to the vibrations transmitted through the inner
ear
Organ of Corti:
region located in the cochlear duct that contains sensory hair cells that detect the sound vibrations transmitted to the inner ear
Organ of corti is distributed along the
sensory epithelium, a
cellular layer on the basilar
membrane
How are action potentials generated in the cochlea?
- vibrations from the eardrum pushes through fluid into the inner ear
- basilar membrane vibrates
3.bends hair cells against the tectorial membrane
4.generate action potentials in afferent neurons leading to auditory regions in the brain
Afferent neurons=
auditory nerve
Auditory nerves will travel to
auditory center in the
temporal lobe of the brain
____attaches tip of
each stereocilium in a hair bundle to the
side of the next longer stereocilium
Tip link (gating spring)
In the process of detection of sounds,as stereocilia bend, they open ____
K+ gates
***Bending steriocilia in one direction depolarizes the cell and stimulates neurotransmitter
release. Applies/opposite
In the basilar membrane, how does
Hair cells in the organ of Corti are “tuned” to certain sound frequencies
by way of their location in the cochlea due to the ___
degree of stiffness in
the basilar membrane
orient stiffness in relation to basilar membrane
Basilar membrane is narrow and stiff near the oval window; wider at the
outer end of cochlear duct
high pitched sounds (which are comprised of high frequency vibrations)
vibrate ___
basilar membrane at its narrow, stiff beginning end
Low pitched sounds vibrate the basilar membrane near
the wider, and
less stiff farther end