Neuro 2000 Auditory Perception/Sensation Flashcards
Explain what sensation is.
detection of an enviornmental stimuli
(ex; smelling brownies)
Explain what perception is.
awareness of what we sense
Give the order of the sensory pathway.
sensory receptor cells -> thalamus ->
primary sensory cortex
Explain the function of the thalamus.
all senses processed through the thalamus before being sent via cerebral cortex for interpretation. plays a role in
-sleep
-wakefulness
-consciousness (alert)
-cognition (forming storage of memories, sexual arousal, learning)
the doctor that diagnoses the problem
Explain the process of transduction.
converts a sensory signal/energy (photon, sound wave) into an electrical impulse for it to be interpreted by the brain.
Explain what sensory receptor cells (exteroceptors) are.
AFFERENT neurons that detect enviornmental stimuli (ex; pain) that is transformmed into neural impulses to be transmitted to the CNS through transduction.
Explain the function of the primary sensory cortex.
-percieve touch
-percieve pressure
-percieve pain
-percieve temperature
Explain the function of an accessory pathway
a path way that involuntary/reflective stimuli go through
pressure over distance
points of compressed and uncompressed air
Explain what sound is.
wave of mechanical energy that travels through air/any medium (molecules bump into each other to push each other along)
low frequency
less often/low pitch
Explain the function of hair cells.
specialized auditory receptor neurons embedded in the basilar membrane BART SIMPSON.
-converts mechanical energy into electrical energy
high frequency
more often/high pitch
low intensity
low volume
What is the hertz range for humans?
20-20,000 hertz
high intensity
high volume
Explain the function of ossicles.
a trio of bones that transfers vibrations or sound waves from the outer ear to the inner ear for auditory transduction.
What three bones make up the ossicles?
malleus (hammer)
incus (anvil)
stapes (stirrup)
Explain what the malleus contains.
contains a head, neck, and handle (manubrium) lateral process, anterior process
Explain what the incus contains.
short limb - stability
long limb
What is contained in the outer ear?
-pinna
-auditory canal
Explain what the stapes contains.
-capitulum
-base
-anterior limbs
-posterior limbs
Explain the function of the basilar membrane.
-holds the auditory receptors (hair cells)
-serves as base layer of the organ of Corti
-propagates sound vibrations that allow the brain to interpret sound
Explain the function of the pinna.
-collects sound waves
-directs sound waves
Explain the function of the eustachian tube.
A narrow tube between the middle ear and the throat.
– equalize air pressure on both sides of the eardrum
Explain the function of the auditory canal
-amplify sounds
Explain the function of the cochlea
-transforms sound waves into electrical impulses so the brain can interpret as sound frequencies
What is contained in the inner ear?
cochlea
semicircular canals
Explain the function of the stereocilia.
make up the individual ‘hairs’ of the hair cell. when bended, converts physical force from sound, head movement, or gravity into an electrical signal.
Explain the process of mechanoelectrical transduction.
converts sound, gravity, or head movement into electrical signals
process is conducted in hair cells at the tip of the stereocilia
Explain the function of the tectorial membrane.
-reinforce traveling waves
-corrects auditory representation of the soiund
-a shelf against which the cilia of the auditory hair cells move
Explain the function and appearance of the tympanic membrane.
thin, oval-shaped membrane
-separates the outer ear from the middle ear
-causes vibration when sound waves reach the TM
Explain the steps to sound conduction.
1) mechanical energy wave in air
2) this wave hits the pinna and is reflected/funneled into the auditory canal
3) waves hit the tympanic membrane which vibrates at the frequency of sound
4) this causes ossicles to vibrate (first the hammer (malleus) then the anvil (incus) then the steric (stapes)
5) this causes the steric to move in and out of the cochlea through the oval window
6) this recreates the waves from the air in the liquid of the cochlea
7) inside of the cochlea the basilar membrane begins to vibrate (base vibrates in a high frequency and apex vibrates in a low frequency)
Explain the function of the TRPA1.
ion channel (mechanically gated potassium channel) is on tips of stereocillia
there is high potassium outside so it will move in causing depolarization
the process of the docking proteins on vesicles getting pulled and releasing neurotransmitters alerts the rest of the nervous system the sound wave
Explain the steps to perception of sound.
1) sensory receptor cells (hair cells) sense sound inside cochlea
2) spiral ganglion neurons gain synaptic connection from hair cells
3) this connects to auditory neuron that goes to the cochlear nucleus (in pons)
4) this goes to the superior olivary nucleus (inside pons) job = localization of sound
5) this goes to the inferior colliculus in the midbrain (reflexive orientation to a novel auditory stimulus)
axons will connect to the superior colliculus that connects to motor neurons for head/neck/eyes which connect to muscle cells which is why we look at sudden stimulus
6) this connects to medial geniculate nucleus inside thalamus and this modulates attention to sound
7) this goes to primary auditory cortex (found in temporal cortex)
8) auditory info from auditory cortex and visual info from the visual cortex put together in association cortex (specifically wernicke’s area in the temporal cortex to help us understand meaning of words)
** hair cells die over time
back of auditory cortex
high frequency sounds
front of auditory cortex
lower frequency sounds
What happens when the basilar membrane vibrates?
- Movement of the hair cells and their sterocilia occurs,
- opening up ion channels
- causes the release of neurotransmitters to propagate the auditory signal to the vestibulocochlear neerve
- then carries the information regarding the auditory stimulus to the brain to be analyzed and percieved.
Explain the process of mechanoelectrical transduction (MET).
hair cells in the inner ear convert mechanical vibrations into electrical signals that allow us to hear.
Explain the function of the association cortex.
recieves information from multiple primary sensory cortices forming the basis for cognition.
in the cerebral cortex
different pieces of info –> spatial relationships (cognitive pathway)
Explain what spatial relationships are.
the ability to recognize and visualize
-shapes
-objects
-determines how they relate to one another
Where are spatial relationships processed?
CATEGORICAL in the left hemisphere
COORDINATE in the right hemisphere
