Chapter17 part8 p.600-603 hearing process Flashcards
Tympanic membrane vibrates in resonance to sound waves w/ frequencies between what range?
20 and 20000Hz
6 steps of hearing process
- sound wave arrive at tympanic membrane
- movement of tympanic membrane cause displacement of auditory ossicles
- movement of tapes at oval window establish pressure waves in perilyph of scala vestibuli
- pressure waves distort basilar membrane on their way to the round window of the scala tympani
- vibration of the basilar membrane causes hair cells to vibrate against tectorial membrane
- Information about the region and the intensity of stimulation is relayed to the CNS over the cochlear branch of cranial nerve VII
Pressure applied at the oval window can be relieved only at what location?
round window
When the stapes move inward, the round window
bulges outward
The perilymph that is connected to the oval window is called
scala vestibuli
the part of the perilymph that is connected to the round window is called
scala tympani
The location of max distortion varies with _________ of the sound, due to regional differences in the width and flexibility of the ____________ along its length
frequency, basilar membrane
High frequency sounds with _______ wavelength vibrate the basilar membrane near ___________
short, oval window
lower sound frequency has _________ wavelength and the maximum distortion area is farther from___________
longer, oval window
information about frequency is translated into info about_________
position along basilar membrane
vibration of the affected region of the basilar membrane moves the hair cells against____________
tectorial membrane
The movement of the hair cells leads to the displacement of the ________, which opens ___________ in plasma membranes of the hair cells.
sterocilia, ion channels
The ________ of ions depolarize the hair cells and cause what?
inrush, release of neurotransmitters that stimulate sensory neurons
Hair cells of spiral organ are arranged in what?
several rows
Cell bodies of the bipolar sensory neurons that monitor the cochlear hair cells are located where?
center of the bony cochlea- spiral ganglion
From the spiral ganglion, the information is carried by what to cochlear nuclei of what for distribution to other centers in the brain?
cochlear branch of cranial nerve VIII, medulla oblongata
Cell bodies of the sensory neurons that are activated by stimulation of hair cells is located where?
adjacent spiral ganglion
AFferent fibers of the auditory sensory neurons form what of what nerve?
cochlear branch of the vestibulocochlear nerve VIII
The axons from the cochlear branch enter what to synapse where?
medulla oblongata, cochlear nucleus
where does the signal go from medulla oblongata cochlear nucleus of what organ
information ascends to superior olivary nucleus of pons and inferior colliculi of midbrain
The midbrain processes responses to acoustic stimuli, including auditory reflexes that involve what muscles of which part?
skeletal muslces, head, face, trunk
What creates the automatic change of the position of our head and eyes toward source of sound?
midbrain processed reflex
Before reaching the cerebral cortex and awareness, the auditory sensation synapse where?
medial geniculate nucleus of the thalamus
Projection fibers deliver information from medial geniculate nucleus of thalamus to
auditory cortex of temporal lobe
How are the frequencies of the sound relayed to the brain
The auditory cortex contains a map of the spiral organ
Most of the auditory info from one cochlea is projected to which part of the brain?
explain the left/right sides+ signal
auditory complex of crebral hemisphere on opposite side of the brain
but each auditory cortex also receives info from cochlea on that side- localization of left/right sounds
name 3 symptoms in ear of getting old
- tympanic membrane gets less flexible
- articulations between the ossicles stiffen
- round window begin to ossify
