auditory and vestibular system Flashcards
the cochlea
basilar membrane
tapered structure
narrow at 1 end and gets wider
topographical mapping of frequences
allows us to distinguish between different frequencies
how is transduction achieved
by mechanical movement of specialised sensory cells
sound waves cause the fluid in the cochlea to
move because of pressure waves
which causes basilar membrane to undulate up and down
endo-cochlea potential
stereocilia are bathed in endolymph (high K+) the base is bathed in perilymph (low K+)
electromotility
depolarisation= contraction hyperpolarisation = relaxation
what is biphasic
depolarisation and hyperpolarisation is K+ dependent
what does tip links do
converts movement into ion conduction
sound in the air reaches what and causes it to
tympanic membrane
causing it to vibrate
what does the tympanic membrane do
causes the 3 bones to vibrate
making the stapes move in and out at the oval window
resulting pressure causes movements in the inner ear fluid
waves through what causes hearing
through basilar membrane up and down movements
stereocilia where are the located
and what doe they do
embedded in the tectorial membrane
bent back and forth when the basilar membrane shifts
what do the shifts in the stereocilia do
the open or close gated ion channels
where do inner ear cells synapse
afferent neurons
increasing neurotransmission increases
rate of firing of afferent neurons
semicircular canals what do they do
they detect changes in movement
3 canals at right angles to each other
receptive hair cells are located where
ampulla
when the head moves what moves with the fluid
cupula
causing swaying and bending
Each hair cell is oriented so that it depolarizes when the stereocilia are bent toward
the kinocilium
otolith organ
provides info on position of the head relative to gravity
hair cells are oriented towards what
the striola
what does the striola cause
which acts as a axis of symmetry
hair bundles on either side of the striola are
of opposite morphological polarization
what detects movement in the horizontal plane
Utricle
what detects movement in the vertical plane
Saccule
