Ch7-Auditory, Mechanical, & Chemical Senses Flashcards
periodic compressions of air, water, or other media
sound waves
audition depends upon our ability to detect _____
sound waves
intensity of a sound wave [measured height a sound wave reaches] - measured in decibels; physical dimension
amplitude
psychological experience of amplitude
loudness
number of compressions per second [how many cycles per second] - measured in hertz; physical dimension
frequency
psychological experience of frequency
pitch
range of frequencies in adults
15hz to 20,000hz
sound waves are transduced into ____ ____ through a complex process
action potentials
helps us locate the source of a sound [includes the pinna]
outer ear
after sounds waves pass through auditory canal, they strike the tympanic membrane [eardrum] in the ____ ____
middle ear
Tympanic membrane connects to three tiny bones that transmit vibrations to oval window
malleus [hammer]
incus [anvil]
stapes [stirrup]
snail-shaped structure in inner ear containing three long fluid filled tunnels [scala vestibuli, scala media, scala tympani]
cochlea
order of structures that sound waves pass through from outer ear to inner ear
pinna, tympanic membrane, oval window, cochlea
vibrations in the fluid of the cochlea displace ____ ____, where action potentials originate
hair cells
basilar membrane resembles strings of a piano - each area [neurons] along membrane is tuned to specific frequency
place theory
downfall of place theory:
various parts of basilar membrane are bound too tightly to resonate like piano strings
basilar membrane vibrates in synchrony with a sound, causing auditory nerve axons to produce action potentials at the same frequency in auditory nerve [50hz causes 50 action potentials per second]
frequency theory
downfall of frequency theory:
neurons cannot respond as quickly as the theory requires [max neuron firing rate is 1000hz]
combines modified versions of both place & frequency theory; low frequency = basilar membrane vibrates in synchrony with sound; high frequency = neuron’s action potentials are phase-locked to pearks of sound waves
current theory
auditory nerve as a whole produces volleys of impulses for sounds up to 4,000 per sec; auditory cells must time their response precisely
volley principle
most human hearing takes place below ____
4,000hz
impaired detection of frequency changes
amusia [tone deafness]
ability to hear note & ID it
absolute [perfect] pitch
axons cross over to opposite hemisphere; info ultimately reaches _______ in superior temporal cortex
primary auditory cortex [A1]
pathway detects patterns of sound
“what” pathway
pathway detects location of sound
“where” pathway
includes areas important for detecting visual motion & motion of sounds
superior temporal cortex [area MT]
area important for auditory imagery
area A1
difference between damage to V1 vs damage to A1
V1 damage = cortical blindness
A1 damage = does not necessarily cause deafness
cortex provides map of sounds called
tonotopic map
hearing loss that results from disease, infection, or tumorous bone growth; prevents middle ear from transmitting sound waves properly to cochlea
conductive deafness [middle-ear deafness]
hearing loss that results from damage to cochlea, hair cells, or auditory nerve
nerve deafness [inner-ear deafness]
nerve deafness often produces ______ [ringing in the ears]
tinnitus
3 cues for sound localization
sound shadow
time of arrival
phase difference
difference in intensity between the ears [head makes the sound louder for the closer ear]
sound shadow
difference in ____ of arrival at the two ears [localize sounds with sudden onset]
time
sound coming from anywhere other than straight ahead or straight behind reaches the two ears at different ______ of the sound wave
phases
_____ senses respond to pressure, bending, or other distortions of a receptor
mechanical
if visually tracking an object while dancing is impaired, which sense is most likely damaged
vestibular
sense that detects position and movement of the head; allows compensatory movements of the eyes
vestibular
calcium carbonate particles that lie next to the hair cells
otoliths
filled with jellylike substance & lined with hari cells
3 semicircular canals
the sensation of the body & its movements; discriminates touch, deep pressure, cold, warmth, pain, tickle, & position and movement of joints
somatosensory system
stimulation of touch receptor opens sodium channels in the axon, causing
an action potential
chemical that stimulates heat receptors (hot peppers)
capsaicin
different sub-areas along each strip of the somatosensory cortex respond to
different areas of the body
experience evokes by harmful stimulus, directs our attention & holds it; keeps us away from dangerous stimuli
pain
prefrontal cortex continues to respond to pain as long as ____
the pain lasts
pain sensation begins with
bare nerve ending
axons carrying pain info have little or no myelin, implicating _____
impulses travel slowly; brain processes pain info rapidly & motor responses are rapid
thicker & faster axons result in ____ pain
sharp
tinner & slower axons result in _____ pain
duller
mild pain causes release of _____ neurotransmitter
glutamate
stronger pain causes release of ______ neurotransmitter
both glutamate & substance P
certain areas react not to the sensation of pain but to the ______ of pain
emotional associations
sympathetic pain [cingulate cortex]
systems that respond to opiate drugs & similar chemicals
opiod mechanisms
[block release of sub P]
implication of discovering opiate receptors
1st evidence opiates act on nervous system, not damaged tissue
natural pain killers, inhibit sub P
endorphins
Which theory states the spinal cord neurons that receive messages from pain receptors also receive messages from touch receptors & from axons descending from the brain
gate theory
general principle of gate theory
nonpain stimuli modify the intensity of pain
placebo’s effect is mainly on emotion, not sensation - decreases response in _______ but not _________
cingulate cortex, somatosensory cortex
worsen pain by increasing anxiety
antiplacebos [nocebos]
when someone experiences social pain, activity increases in the
cingulate cortex
Why is itch useful?
It directs you to scratch the itchy area & remove whatever is irritating your skin
there is an _____ relationship between pain & itch
inhibiting
each receptor responds to a limited range of stimuli, and the meaning depends entirely on which neurons are active [3 bells, each sends only 1 msg]
label-line principle
each receptor responds to a wider range of stimuli, and a given response by a given axon means little except in comparison to what other axons are doing [3 bells, combo of bells means different things]
across-fiber pattern principle
nearly all perceptions depend on the pattern across an array of axon; this is the __________ principle
across-fiber pattern
_____ is a combo of taste & smell
flavor
taste & smell axons converge onto many of the same cells in the _______ cortex
endopiriform
receptors for taste are _________; not true neurons
modified skin cells
bumps on the tongue where taste buds receptors are located
papillae
where are human taste buds located?
outer edges of tongue
primary tastes [5]
sweet, salty, bitter, sour, unami
reflects the fatigue of receptors sensitive to a certain taste [ex) after eating salty pretzels, salty chips will taste less salty due to _____]
adaptation
reduced response to one taste after exposure to another
cross-adaptation
taste nerves project to the ____________ [NTS] in the medulla; from NTS info branches out
nucleus of the tractus solitaries
responds to touch stimulation on tongue
somatosensory cortex
primary taste cortex
insula
have highest sensitivity to all tastes & mouth sensations
supertasters
variations in taste sensitivity relate to number of _______ near tip of tongue
fungiform papillae
neurons responsible for smell; located on cilia
olfactory cells
how many olfactory receptors do we have?
several hundred
how is olfactory info coded in receptor cells?
there are hundreds of types of receptor molecules, each responsive to a different chemical
we arrange our olfactory receptors over the entire surface of the nasal passages
localization
olfaction is subject to more rapid ______ than sight or hearing
adaptation
when an olfactory receptor is stimulated, its axon carries an impulse to the ________, which then sends axons to _________ of cerebral cortex
olfactory bulb, olfactory area
experience of one sense in response to stimulation of a different sense
synesthesia
