Lecture 16 Flashcards
ossicles are __
3 bones in the middle ear - malleus, incus and stapes
conduction of sound waves is based on the __ movement of __
alternating movement; the basilar and tectorial membranes
the movement of the basilar and tectorial membranes __ the bundles of hair cells
stretches and relaxes
between the basilar and tectorial membranes is __ and __ that __ the sound
hair cells and stereocilia; transduce
the __lymph is between the basilar and tectoral membranes and contains the hair cells
perilymph
the __lymph is in between the tectorial and vestibular membranes
endolymph
movement of the fluid in the ear has __ and __; waves __ through this aqueous environment
frequency and amplitude; propagate
hair cells are __receptors, meaning __ activates the receptor channels
mechano; a physical force
hair cells are what underly the __
transduction of auditory stimuli
the bottom of hair cells are attached to the __
basilar membrane
fluid wave movement causes the __ membrane to move, causing the __ to move
basilar; stereocilia
stereocilia can only move __. when they stretch (move in the direction of __) it causes __ channels to open and it is the influx of this __ that __ the membranes/hair cells
in one plane; the longest hair; K; K; depolarizes
when stereocilia move in the direction of __ (slackening/no tension), the hair cell __ because/and __ channels are closed
the shortest hair; hyperpolarizes; K
after depolarization, __ is released and picked up by the __ and action potentials are sent on to the brain
glutamate; afferent nerve
dynamic effects of K? it’s functioning to both __
depolarize AND hyperpolarize the hair cells
different fluid regions contain different __
ion concentrations
perilymph (or __) and endolymph are __
scala tympani; fluid-filled regions
endolymph is super __ in K concentration (so when hair cells are stretched and K channels open, K goes into the cell __)
high; along its concentration gradient
perilymph is super __ in K concentration (so when hair cells are slack, K leaves the cell __)
low; along its concentration gradient
at rest about __ percent of K channels are open, so there is __ at rest
10; a tonic signal
when stereocilia are stretched the membrane potential is __ than at rest and we see more __
higher; action potentials
when stereocilia are slacked the membrane potential is _- than at rest and we see less __
lower; action potentials
characteristic frequency = __
the frequency at which you have peak sensitivity (lowest threshold to respond)
each neuron/receptor responds best to a particular __
frequency
frequency coding in the basilar membrane: near the apex we’re going to have __ that are __ the hair cells; towards the base of the __ we’re going to need __ to do the same thing
low frequency; exciting; cochlea; higher frequencies
auditory cortex is organized in a __
topographic map
the __ region of the auditory cortex corresponds to the apex. the __ region of the auditory cortex corresponds to the base of the basilar membrane
anterior or rostral (front); posterior or caudal (back)
going from apex to base of basilar membrane (and thus from __ region of AC to __ region), do sounds get lower or higher?
front; back; higher
visual system processes light __
reflected off distant objects
visual system helps us __ (3)
identify objects (shape, color, texture), localize objects, and asses movement
visual system is very __
quick
visual stimuli are transduced by __
photoreceptors
signals conveying visual info leave the retina via __ that convey these signals from the eye to the brain
retinal ganglion cells
are the left and right visual fields represented in each eye?
yes
light = __, photons/waves of various levels of energy
electromagnetic radiation
high energy light = __ wavelength, __ frequency
lower energy = __ wavelength, __ frequency
shorter; higher; larger; lower
visible light falls within __ nm
400-700
hot colors are __ energy and cold colors are __ energy
lower; higher
light of mixed wavelengths = __
light of one wavelength = __
white; color
accommodation =
dynamic changes in the lens in response to where you are looking (far or near)
myopia = \_\_, the image of distant objects are in focus \_\_ hyperopia = \_\_, the image of distant objects are in focus \_\_
nearsightedness; in front of the retina; farsightedness; behind the retina
retina = __ of cells and __ of synapses (__ types of cells)
3 layers; 2 layers; 5 types
in the retina: light goes from __ but information goes from __
front to back; back to front
the retina is specialized to detect __ intensity, not __ intensity
differences in; absolute
5 types of cells in retina
photoreceptors, bipolar cells, horizontal cells, amacrine cells, and retinal ganglion cells
2 types of photoreceptors
rods (light/dark) and cones (color)
the outer segment of __ have more discs, this is what underlies their greater __
rods; sensitivity to light
after a certain point of brightness, rods begin to __ and then cones take over for __
saturate; photopic vision
scotopic vision =
lowest level of illumination, only rods activated, no color vision, poor acuity
mesopic vision =
both rods and cones active
photopic vision = best __, good __, __ active
visual acuity; color vision; only cones
the __ in the photoreceptor disk membranes absorb light of __
photopigments; specific wavelengths
photopigments in rods is __
rhodopsin
__ types of -opsins for cones, that absorb different ranges of wavelengths
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