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167 Cards in this Set
- Front
- Back
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External ear?
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Hearing; terminates at eardrum
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Middle ear?
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Hearing; contains auditory ossicles
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Inner ear:?
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Hearing and balance; interconnecting fluid-filled tunnels and chambers
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External Ear Function?
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collect sounds
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auricle or pinna ?
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elastic cartilage covered with skin
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external auditory canal ?
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curved 1” tube of cartilage & bone leading into temporal bone
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ceruminous glands produce?
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cerumen = ear wax
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tympanic membrane or eardrum?
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epidermis, collagen & elastic fibers, simple cuboidal epith.
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Perforated eardrum at time of injury give you?
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pain, ringing, hearing loss, dizziness
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Middle Ear Cavity?
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Air filled cavity in the temporal bone
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Separated from external ear by eardrum and from internal ear by oval & round window?
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Middle Ear Cavity
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Middle Ear Cavity has 3 ear ossicles connected by?
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synovial joints
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malleus attached to eardrum, incus, & stapes attached by?
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a foot plate to membrane of oval window
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stapedius and tensor tympani muscles attach to?
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Ossicles
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Auditory (Eustachian) tube leads to?
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Nasopharynx
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Auditory (Eustachian) tube?
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helps to equalize pressure on both sides of eardrum
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Mastoiditis?
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Irritation of the mastoid bone
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Middle ear cavity connects to?
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Mastoid bone
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Tensor tympani attaches to?
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Malleus
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Tensor tympani limits movements of?
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Malleus
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Tensor tympani stiffens eardrum to?
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prevent damage
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Tensor tympani is innervated by the?
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mandibular branch of the trigeminal nerve (CN V)
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Stapedius m. inserts onto?
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Stapes
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Stapedius muscle prevents?
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very large vibrations of stapes from loud noises
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Stapedius muscle innervated by?
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CN VII
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Bony labyrinth =?
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set of tubelike cavities in temporal bone
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Bony labyrinth has semicircular canals, vestibule & cochlea lined with?
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periosteum & filled with perilymph
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Bony labyrinth surrounds & protects?
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Membranous Labyrinth
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Membranous labyrinth =?
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set of membranous tubes containing sensory receptors for hearing & balance and filled with endolymph
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Membranous labyrinth parts ?
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utricle, saccule, ampulla, 3 semicircular ducts & cochlea
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Cochlea?
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Hearing
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Vestibule:?
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Balance
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Why is Endolymph similar to cytosol?
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high level of K+
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Endolymph is located??
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In membranous labyrinth
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Perilymph is similar to?
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CSF
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Perilymph is located?
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Space between membranous and bony labyrinth
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Vestibulocochlear nerve = CN?
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VIII
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ampullary, utricular & saccular brs. Form?
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vestibular branch
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cochlear branch has spiral ganglion in?
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bony modiolus
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Semicircular canals:?
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Balance
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What are the 3 fluid filled channels found within the cochlea?
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scala vestibuli, scala tympani and cochlear duct
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Vibration of the stapes upon the oval window sends vibrations into?
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the fluid of the scala vestibuli
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Partitions that separate the channels of Cochlea are?
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Y shaped
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vestibular membrane above & basilar membrane below form the?
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central fluid filled chamber (cochlear duct)
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Fluid vibrations affect hair cells in?
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cochlear duct
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16,000 hair cells have 30-100?
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stereocilia(microvilli )
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Microvilli make contact with?
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tectorial membrane
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tectorial membrane?
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gelatinous membrane that overlaps the spiral organ of Corti
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Basal sides of inner hair cells synapse with?
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1st order sensory neurons whose cell body is in spiral ganglion
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Stapes pushes on fluid of scala vestibuli at?
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oval window
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At helicotrema, vibration moves into?
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scala tympani
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Fluid vibration dissipated at?
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round window which bulges
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sound waves
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Vibrating object causes compression of air around it
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audible range is
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20 to 20,000 Hz
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hear best within
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500 to 5000 cycles/sec or Hz
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speech is how many Hz?
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100 to 3000 Hz
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Frequency of a sound vibration is
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pitch
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higher frequency is
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higher pitch
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Greater intensity (size) of vibration, the ?
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louder the sound measured in decibels (dB)
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Conversation is (Hz)?
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60 dB
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pain above (Hz)?
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140dB
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OSA requires ear protection above?
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90dB
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Auricle collects
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sound waves
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Eardrum vibrates:
slow vibration in response to ? |
low-pitched sounds
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Eardrum vibrates:
rapid vibration in response to ? |
high-pitched sounds
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Ossicles vibrate since ?
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malleus attached to eardrum
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ossicles are ?
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“bone amplfier”
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Stapes pushes on oval window producing ?
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fluid pressure waves in scala vestibuli & tympani
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oval window vibration 20X more vigorous than
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eardrum
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Pressure fluctuations inside cochlear duct move?
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the hair cells against the tectorial membrane
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Microvilli are bent producing
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receptor potentials
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Volume or loudness : Function of ?
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wave amplitude
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Pitch: Function of ?
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wave frequency
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Timbre
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Resonance quality or overtones of sound
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Sounds at different frequencies vibrate different portions of the ?
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basilar membrane
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high pitched sounds vibrate the stiffer more basal portion of the?
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cochlea
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low pitched sounds vibrate the upper cochlea which is ?
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wider and more flexible
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Louder sounds cause a greater vibration of the ?
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basilar membrane
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___________ sounds stimulate more hair cells which our brain interprets as “louder”?
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Louder
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Hair cells convert mechanical deformation into ?
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electrical signals
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As microvilli are bent, mechanically-gated channels in the membrane let in ?
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K+ Ions
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This depolarization spreads & causes voltage-gated Ca+2 channels at the base of the cell?
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to open
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Triggering the release of neurotransmitter onto the first order neuron more ?
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neurotransmitter means more nerve impulses
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Cochlea can produce ?
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inaudible sounds
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inaudible sounds caused by ?
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shortening & lengthening of outer hair cells in response to signals from motor neurons
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Otoacoustic Emissions can be recorded by ?
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sensitive microphone next to the eardrum
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With Otoacoustic Emissions vibration travels backwards toward the ?
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eardrum
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In Otoacoustic Emissions as outer hair cells shorten, they stiffen the
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tectorial membrane
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Otoacoustic Emissions amplifies the responses of the ?
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inner hair cells
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Otoacoustic Emissions increase our ?
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auditory sensitivity
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Cochlear branch of CN VIII sends signals to ?
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cochlear nucleus in the medulla (on the same side)
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signals travel from the cochlear nucleus in the medulla (on the same side) to?
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the superior olivary nuclei (of both sides) in the pons
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differences in the arrival of impulses from both ears, allows us to?
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locate the source of a sound
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In The Auditory Pathway Fibers ascend to the (3)?
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inferior colliculus
-thalamus -primary auditory cortex in the -temporal lobe (areas 41 & 42) |
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damage to hair cells from antibiotics, high pitched sounds, anticancer drugs = ?
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Nerve deafness
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fail to notice Nerve deafness until difficulty ?
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with speech
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Conduction deafness is associated with?
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-perforated eardrum
-otosclerosis |
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One can get Cochlear Implants If deafness is due to destruction of?
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hair cells
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Cochlear Implants = ?
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Microphone, microprocessor & electrodes
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Microphone, microprocessor & electrodes translate sounds into?
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electric stimulation of the vestibulocochlear nerve
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artificially induced nerve signals follow
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normal pathways to brain
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Cochlear Implants provides only a ?
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crude representation of sounds
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VESTIBULAR SYSTEM =
Two components? |
1. Dynamic
2. Static |
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Dynamic = ?
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detection of linear and rotational acceleration/deceleration;
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Static = ?
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detection of head orientation in space relative to gravity.
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Two purposes of the vestibular system: ?
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1. Control eye reflexes to achieve fixation at a point
2. Control reflexes for postural control |
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Static equilibrium = maintain the position of the body (head) relative to ?
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the force of gravity
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macula receptors within ?
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saccule & utricle
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Dynamic equilibrium = maintain body position (head) during ?
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sudden movement of any type - rotation, deceleration or acceleration
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crista receptors within ?
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ampulla of semicircular ducts
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The Detection of angular acceleration/deceleration happens with the help of ?
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3 semicircular canals
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3 semicircular canals are Filled with ?
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endolymph
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Receptor – crista ampullaris: cupula with ?
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sensory hair cells embedded in gelatinous membrane
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Receptor Detection sensitivity = ?
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1 degree/second/second
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hair cells are not stimulated when there is (2)?
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no movement or movement at constant speed
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Posterior canal =
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left & right (head tilt)
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Superior Canal = ?
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nod for yes
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Horizontal canal = ?
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shake head for "no"
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Crista = ?
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Small elevation within each of three semicircular ducts
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anterior, posterior & horizontal ducts detect ?
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different movements
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Hair cells covered with?
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cupula of gelatinous material
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When you move, fluid in canal bends cupula stimulating ?
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hair cells that release neurotransmitter (glutamate)
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When head moves, the attached semicircular ducts and hair cells move ?
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with it
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endolymph fluid does not move when the head moves and ?
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bends the cupula and enclosed hair cells
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Nerve signals to the brain are generated indicating ?
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which direction the head has been rotated
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– the kinocilium is located always on one side of the
hair cells and? |
on the same side overall in the cupula
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frequency of action potential depends on ?
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magnitude and direction of force on hair cells.
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This is unlike many other neurons whose action potential
frequency depends? |
only on stimulus magnitude.
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maculae are perpendicular to?
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one another
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hair cells embedded in gelatinous membrane contain?
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otolyths
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Hair cells are oriented in different directions so that some are stimulated when ?
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head beand forward OR backwards
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otolyths are ?
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calcium carbonate crystals with (glyco)proteins
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Otolyths detection sensitivity ?
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0.5 degree (decreases with increase in tilt)
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Otolithic Organs = ?
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Thickened regions called macula within the saccule & utricle of the vestibular apparatus
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Cell types in the macula region?
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-hair cells with stereocilia (microvilli) & one kinocilium (cilia)
-supporting cells that secrete gelatinous layer |
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Gelatinous otolithic membrane contains calcium carbonate crystals called ?
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otoliths that move when you tip your head
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Movement of stereocilia and kinocilium results in ?
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the release of neurotransmitter onto the vestibular branches of the vestibulocochler nerve
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Sensory (hair) cells to ?
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primary sensory neurons in vestibular nerve (VIII)
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Primary sensory neurons in vestibular nerve (VIII) to
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vestibular nuclei of medulla (brain stem)
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cerebellum to ?
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reticular nuclei
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Describe the two intergrative pathways?
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1. down into brain stem and spinal cord for controlling antigravity muscles;
2. upward into midbrain for controlling thalamus -> cerebrum |
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Vestibular nuclei ?
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motor neuron of eye movement and postural reflexes
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Fibers from vestibulocochlear nerve (VIII) end in ?
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vestibular nuclei in the medulla and the cerebellum
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Cerebellum receives constant updated sensory information which it sends to?
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the motor areas of the cerebral cortex
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motor cortex can adjust its signals to ?
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maintain balance
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cranial nerves that control eye and head and neck movements (4)?
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III, IV, VI & XI
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vestibulospinal tract adjusts postural skeletal muscle contractions in response to ?
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head movements
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Vertigo = ?
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– the sensation of spinning with respect to the environment
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Vertigo Direction of sensation depends on which semicircular canal is?
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stimulated and is oriented in the direction opposite to the endolymph displacement (in the direction of rotation).
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Autonomic responses of vertigo (4)?
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nausea and vomiting, pallor, perspiration
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Autonomic responses of Very intense vertigo (4)?
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cardiac, vasomotor and respiratory responses which can lead to hypotension and hyperpnea.
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Nystagmus = ?
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an oscillatory eye movement
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Slow component ?
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always in the direction of
flow of endolymph. |
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Fast component ?
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– the recovery phase of eye rotation (this is the direction of nystagmus) – in direction opposite to flow of endolymph.
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Slow component Reflex arc – (afferent): ?
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cristae to vestibular
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Slow component Reflex arc – (efferent): ?
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vestibular center to extrinsic
eye muscles |
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Fast component Reflex arc – afferent: ?
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cristae to vestibular
nuclei in the brain stem to vestibular reticular formation in brain stem |
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Fast component Reflex arc – efferent: ?
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reticular formation to eye muscles.
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Motion sickness
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a physiological response to abnormal body motion and visual experience
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Motion sickness Treatment ?
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dimenhydrinate
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antibiotics such as aminoglycosides (strepto-, kana-, genta-, neomycin) damage ?
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damage inner ear hair cells and otolyths = cause hearing loss and equilibrium disturbances.
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Menier’s disease
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Characterized by hearing loss, tinnitus (ringing in the ear) and attacks of vertigo.
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Menier’s disease is Caused by ?
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overproduction or underabsorption of endolymph.
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Endolymph is continuously secreted by ?
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epithelial cells = cerebrospinal fluid
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Endolymph drains into the ?
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venous sinus of dura mater of the brain
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Endolymph rate of synthesis = ?
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rate of removal
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functions of the endolymphatic sac (ES) (three)?
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Breakdown and removal of waste products from the endolymphatic proteins and otoconia
Secretory activity primarily in the form of acidic glycoproteins referred to as "homogeneous substance" (HS) which normally fills the ES lumen Volume regulation of the endolymph by cycles of secretion and degradation/resorption of the osmotically active HS |
