Module 6 Flashcards
the ear transforms energy from acoustic waves to ?
after leaving the ear auditory information is ?
hearing takes place in the ?
electrical impulses the brain can interpret
transmitted and processed in the neural pathway from the ear to the brain
brain
Parts of the auditory system:
1. Outer ear: collects and shapes
- middle ear: performs ? to overcome resistance to ?
- inner ear: houses the ? as well as the ? which performs temporal and spectral?
- neural pathways of the auditory system ?
- cerebral cortex:
frequency components of soundwaves
impedance matching/ sound transfer into the fluid filled cochlea
vestibular system/ cochlea/ analyses of acoustic signal
(CN VIII and auditory pathway) covey and process auditory signal from cochlea to cerebral cortex
interprets signal - hearing happens here
outer ear: collects and ?
what two components: (aka?) and ?
separated from middle ear by ?
and shapes sound
pinna (auricle) and external auditory meatus (ear canal)
tympanic membrane (eardrum)
ear canal hair and cerumen:
the outer third of the ear canal has ? these hairs perform a ?
cerumen (aka?) also has useful function. It helps ? it also helps?
tiny hairs / protective purpose as they help trap debris
ear wax/ moisten and lubricate the skin of the ear canal/ trap debris
Tympanic Membrane:
three layers :
attaches to ? so it is slightly ?
epithelial (external) fibrous (intermediate) -radial -circular mucuous membrane (internal)
malleus at the umbo / concave
Middle Ear:
sound is transmitted from the eardrum to the inner ear via ? the ? the smallest ?
eustachian tube connecting middle ear to ? is opened by the ? to provide ? and to ?
“bony bridge”/ossicular chain/ bones in the body / malleus incus and stapes
nasopharynx/ tensor veli palatini / oxygen to the middle ear and to equalize pressure on both sides of the tympanic membrane
Middle Ear functions: overcomes impedance mismatch between an ? and provides a signal gain of about ? -difference between the size of the ? -lever effect ? -buckling movement of ?
reflexive action of stapedius and tensor tympani ? providing some portection from ?
air-filled system and the fluid filled inner ear / 31dB
- tympanic membrane and the oval window
- size/mass of malleus compared to stapes
- tympanic membrane
-stiffens ossicular chain/ loud low frequency sounds
Ossicular connections:
manubrium of malleus attaches to the ?
head of the malleus articulates with the body of the incus via ?
lenticular process of incus articulates with the ?
footplate of the stapes rests in the ?
tympanic membrane
malleolar facet
head of the stapes (incudostapedial joint)
-oval window of the temporal bone
Middle ear muscles:
-
attach to ?
smallest ?
stapedius
tensor tympani
ossicles
muscles in the human body
Stapedius:
rotates ?
footplate of stapes posteriorly stiffening ossicular chain
Tensor tympani: pulls malleus?
anteromedially/ stiffening ossicular chain
Eustachian tube: also called ?
aerates ?
-provides ?
-maintains ?
dysfunction can have serious ?
auditory tube and pharyngotympanic tube
middle ear
- oxygen for middle ear tissue
- pressure equalization between middle ear and outside atmosphere
consequences (negative middle ear pressure, middle ear fluid, infection, conductive hearing loss)
Inner ear:
the inner ear houses ?
it can be divided into three main sections
organs of hearing and balance
vestibule
semi-circular canals
cochlea
Bony Labyrinth:
the tunnel like cavities within the petrous portion f the temporal bone are called the ?
the petrous portion of the temporal bone is the most ?
epithelial lining secretes?
bony labyrinth (also called the osseous labyrinth)
dense bone in the human body
perilymph
Membranous Labyrinth: like a ? doesnt completely fill ? filled with ? houses the actual organs of ?
fluid filled sac resting within the bony labyrinth
the bony labyrinth
endolymph
balance and hearin g
Vestibule:
Lateral wall of the vestibule contains the ?
vestibule connects to both the ?
the otolithic organs of the vestibular system ? are located in the ?
oval window (into which the footplate of the stapes is embedded)
vestibular mechanisms and the hearing mechanisms
utricle and saccule/ vestibule
Semi-Circular Canals:
three ring like structures, each oriented in a different plane ?
SC canals open into the ? the vertical canals share an ?
expanded regions near the areas where the SC canals open to the ?
at right angles to others (anterior vertical, posterior vertical, and lateral)
vestibule/ aperture, the crus commune
vestibule are called ampullae
Cochlea:
contains the organ of ?
often described as a ?
in humans, has about ?
core about which it coils is called the ?
-core of the modioulus is continuous with the ? through which the ? passes
hearing
coiled, snail like shape
2 5/8 turns
modiolus
-internal auditory meatus of the temporal bone/ vestibulocohlear nerve (CN VIII) passes
organ of corti:
the organ of?
located within the ?
filled with ?
-
-
hearing
scala media
-endolymph
stereocilia
- outer hair cells
- inner hair cells
- separated by tunnel of corti
Outer hair cells (OHC)
- approx?
- arranged in three rows (text says rows broaden to ? near apical end)
- shaped like
- tips embedded in ?
- excitation primarily the result of ? as cilia are ?
- one to many ? each OHC shares CN VIII innervation with ?
12000 four -test tubes -tectorial membrane -shearing effect / displaced relative to tectorial membrane
-pattern/ 10 other OHCs
Inner Hair Cells (IHC) approx? arranged in? shaped like ? near ? but not ? excitation produced by efect of ? many to one ? each ihc IS CONNECTED TO AS MANY AS ?
3500 one row tear drops or gourds tectorial membrane/ embedded fluid flow and turbulence of endolymph innervation pattern/ 10 CN VIII nerve fibers
Other Cochlear Areas:
helicotrema: region through which ?
round window: membrane covered opening between?
cochlear aqueduct: tiny opening between ?
scala tympani and scala vestibuli comm.
between scala tympani and middle ear
scala tympani and subarachnoid space of cranial cavity
Cochlear Membranes:
basiliar membrane: forms ?
tectorial membrane: overlays ?
reissner’s membrane: separates ?
floor of scala media (cochlear duct)
hair cells of cochlea
scala vestibuli and scala media (cochlear duct)
Frequency Specificity:
healthy young human auditory mechanism is sensitive to frequencies between about ?
cochlea has ? high frequency sounds are resolved at ? and low freq. sounds at the ?
tonotopic org. is also present in the ?
20 Hz and 20,000 Hz (approx. 10 octaves)
tonotopic org./basal end/apex
auditory pathways and cerebral cortex of the brain
The travelling wave:
georg von bekesy’s work helped establish ?
design of basilar membrane supports ?
freq. components of complex sounds can be processed in ?
understanding of this phenomenon
wave action corresponding to stimulus freq.
different portions of the basilar membrane
Basilar membrane and freq.:
the basilar membrane’s design contributes to our ability to ?
graded stiffness
graded thickness
graded width
analyze freq.
basal end is stiffer than apical end
basal end is thinner than apex
basal end is narrower than apex
Freq. perception:
-
-
1%
100 Hz vs 101 Hz
1000 Hz vs 1010 Hz
10,000 Hz vs 10,100Hz
Retro-Cochlear pathways
information travels through cranial nerve VIII through the ? and up to the ?
decussation ? of nerve fibers allows each side of the brain to ?
brainstem/auditory cortex of the brain
(crossing over) receive input from both ears
