List 4 Vocab Flashcards
1
Q
Intensity Level
A
- amount of energy transmitted (as by acoustic or electro magnetic radiation) the logarithm of the ratio of 2 intensities, powers, or energies.
- usually expressed in dB
2
Q
interference
A
- if source generates a sound continuously both incident and reflected waves will be present at the same time
- at any point when these waves interact it may lead to an increase or decrease in sound pressure
3
Q
Acoustic impedance - American STD
A
- known as acoustic ohms which is the pressure to move a unit volume of the medium per second
4
Q
Specific acoustic impedance
A
- this is Z
- aka shock impedance
- ratio of sound pressure (p) to particle velocity (v) at a single frequency and is expressed in rayls
5
Q
azimuth
A
- the source of sound can be localized in 3 different spatial dimensions
- horizontal plane
6
Q
amplitude
A
- the magnitude of wave
- i.e. how high it goes on y axis
7
Q
inertia (mass)
A
- amount of inertia object has directly proportional to the mass of object
- larger force is required for a more massive object to start, stop, or change direction
- note: all bodies remain at rest or in state of uniform motion unless another force acts in oppositions (newton’s 1st law)
8
Q
damping
A
- gradually reduces degree of oscillation, vibration, or signal intensity or prevents it from increasing
- ex. sound-proofing technology dampens the oscillations of sound waves
- built in dampening is crucial design element in technology that involves the creation of oscillations and vibrations
9
Q
spiral modiolar artery
A
- the major arterial supply to the cochlea, it supplies the apical portion of the cochlea
- originates from the cochlear branch of the vestibulo-cochlear artery
10
Q
inner sulcus cells
A
- line space underneath the tectorial membrane
- support
- tight junctures
- all together junction of endolymph/ perilymph division
11
Q
Hensen Cells
A
- tall supporting cells constituting the outer border of the organ of corti
- henson’s strip - comes close but does not touch IHC
- border after dieter’s cell/claudius cells
12
Q
presynaptic body
A
- found at presynaptic juncture between the hair cell and auditory nerve
- it’s function is to aid in the quick release of neurotransmitters
13
Q
subsynaptic cistern
A
- in synaptic zone of OHC
- feature of efferent not afferent
- stores calcium, releases when nerve terminal releases
- subsurface cisternae ends in sub-synaptic cistern at a nerve ending of OHC
- efferent nerve endings attach to cell opposing this region, efferent synapse onto type II hair cell is marked by this
14
Q
recticular lamina
A
- top surface of organ of corti
inner hair cell -> lateral outer hair cell - below basal lamina, collagenous fibers, anchors the basal lamina to underlying connective tissue
- true chemical divisions between ions in the fluids of scala media (endolymph) and scala tympani (perilymph)
15
Q
Deiters’ Cells
A
- body, stalk (phalangeal process), enlargement at top
- dieters’ cups hold OHC, rigid structures that grab on to OHC, leave room only synapses
- space of neul - room to move, only tight attachment at top and bottom (between OHC and deiters’ cell)
- contain thin strand of tubular & microfilaments
- phalangeal process forms recticular lamina
16
Q
venules at the basilar membrane
A
- vessels with a distinct spiral shape that are located just below attachment of the basilar membrane to the spiral ligament
17
Q
arterioveinous shunts
A
- passageways between an artery and a vein
18
Q
vessel at the vestibular membrane
A
- vessel of the scala vestibuli is a net of capillaries that run spirally forming a basal border of the capillary net
19
Q
vessel of the scala vestibuli
A
- originating from the primary radiating arerioles, this vessel is made up of a smaller set of radiating arterioles and supply all the blood flow to the external wall vessels
20
Q
vessel of the basilar membrane
A
- a spiral blood vessel that lines the basal side of spiral lamina, under the tunnel of cord, supplied by radiating arterioles
21
Q
vessels of tympanic lip
A
- capillary arcade (net), supplied by the radiating arterioles, that supplies the tympanic lip with oxygen
22
Q
limbus vessels
A
- net of capillaries that supply the limbus with blood, which is supplied by the radiating arterioles
23
Q
labyrinthine artery
A
- continuation from basilar artery, splits into the common cochlear artery and anterior vestibular artery
24
Q
outer hair cell features
A
- shaped like cylinder
- nucleus towards base while mitochondria are situated in groups around lateral wall at apex
25
anterior inferior cerebellar artery
- first branch of basilar artery, leading into labyrinth
26
inner hair cell features
- flask shaped
- central nucleus and mitchondria are scattered, nerve endings are near base of cell while organelles are most abundant at apex
27
basilar artery
- primary blood supply to labyrinth
- immediate flow to ear
- > vein cochlear aqueduct
- > spiral modialar artery, near scala vestibuli
28
vertibral arteries
- vertibral artery simply becomes the basilar artery which supplies the labyrinth
29
stria vascularis
- upper portion of the spiral ligament containing numerous capillary loops and small blood vessels
- somewhat stratified into marginal, intermediate and basement cells
- produces endolymph
- 3 cell types:
- - marginal
- - intermediate
- - basal cells
30
Receptor pole
- transduction occurs here
- cuticular plate - where stereocilia attach
- w shape, all attached by tip-links move as i essentially
- taper towards attachment area
- pivot about base
- - reinforcement material makes strong enough doesn't bend too much only pivot
- insertion into cuticular plate:
- - rootlets: anchor to plate
- - hairlets
- - basal body: cuticle free zone, shapes w
31
golgi zone (subcuticular) of IHC
- hair bundle inserts into and is anchored by this plate, a meshwork of actin fillaments
- extends across apical surface of hair cell
- golgi apparatus here
32
marginal (dark) cells
- involved primarily ink + transport & line the endolymphatic space of scala media
- packed with mitochondria
- tight junction with scala media
33
2 types of hair cells
Type A: primarily efferent innervation, dominant in the base
Type B: primarily afferent innervation, dominant in apex
34
basement cells
- separate stria vascularis from underlying spiral ligament
| - middle of two different types of embryonic cells, came from two different places during embryonic development
35
spiral modiolar vein
- beginning of veinous drain from spiral modiolar artery and drains into the cochleomodiolar vein, which joins up with veinous system of vestibular apparatus at the vein of cochlear aqueduct
36
vessel of the spiral prominence
- supplied by radiating arterioles
- spirally directed ridge of tissue between the stria vascularis and basilar membrane
- made up of omega shaped capillaries that run through spiral prominence
37
laminated cisternae
- inside OHC in supranuclear zone
38
tectorial membrane
- primarily collagen
- floats over fluid space over inner spiral sulcus
- connected to endolymphatic space
- one end attached to limbus, over organ of corti at other side loosely attached
- 1/2 membranes of cochlea (other BM)
- 3 zones:
- - limbal: attachment to limbus
- - middle
- - marginal: band loosely attached to the organ of corti
39
Marginal Zone (Band) of the TM
- loose connection to organ of corti
- allows it to move as basilar membrane moves
- klimuras membrane: attaches to OHC directly
- hensons stripe over steriocilia of IHC close to but doesn't touch
40
Middle Zone of TM
- fibrous layer between
41
Limbal Zone of TM
- connects to the limbus
| - floats over fluid space over inner spiral sulcus
42
radiating arterioles
- branch out from the spiral modiolar artery
43
tonofilaments
- found in both pilar & dieters cells
- tubulin & actin, run from head to base, microtubules fan out into base and into head
- dense rigid structure to provide support
- made up of microtubules
44
pillar cells
- form archway in the middle of the cochlea
- paired, heads lock together, looks like wishbone-ish
- feet sitting on/attached to BM
- in between inner and outer hair cells
- - keep endolymph and perilymph seperated
- give organ of corti rigidity, tunnel of organ of corti is perilymph
- head: endolymph
- stalk: connect head and feet, tonofollaments run through to provide support
45
OHC synaptic zone
- efferent and afferent nerve terminal in soma
- rod like structures that are fairly dense, attached to synaptic structures
- regulate gain of cochlear amplifier
- subsynaptic cistern
- - feature of the efferent synapse not afferent
- - stores calcium
- - when nerve terminal release calcium
46
Supranuclear Zone (OHC)
- laminated cisternae, inside of OHC
| - protein prestin, motor protein of cell membrane, makes cell lengthen and shorten
47
subcuticular OHC zone
- lysosomes, organelle turnover
- mitochondria, energy "provide the juice"
- henson body - calcium metabolism, control the calcium metabolism which ultimately controls transduction, homeostatic mechanism
48
musculotubal canal (of carotid wall)
- thin canal that separates the auditory (eustachian) tube and the tensor tympani
- located at the anterior border of the petrous portion of the temporal bone near its junction with the squamous portion
49
tensor tympani (of musculotubal canal - of carotid wall)
- stiffens the ossicular chain to reduce transmission of sounds of low frequency (damping)
- may serve to protect the ear from noise damage
- attached to the malleus hear the tympanic membrane & is innervated by the trigeminal (v) cranial nerve
50
eustachian tube (of musculotubal canal of carotid wall)
- aka auditory tube
- canal that establishes communication between the middle ear and the nasopharynx
- 2 functions: permit drainage of normal and diseased middle ear secretions from middle ear cavity into the nasopharynx and permit middle ear pressure to equalize with external air pressure
- approx 35 to 28 mm in adults
- can be 4 portioned into 4 sections:
- - osseous
- - cartilaginous
- - membranous
- - isthmus
51
labyrinthine wall
- aka medial wall of the tympanic cavity
- verticall directed
- landmarks:
- - oval window
- - promontory
- - round window
- - prominence of the face nerve canal
52
promontory (of the labyrinthine wall)
- rounded protrusion into the middle ear cavity, formed by the lateral projection of the first turn of the cochlea
53
Jacobson's nerve plexus (of labyrinthine wall)
- jacobson nerve = tympanic nerve
- branch of glassopharyngeal nerve (cranial nerve IX)
- branches into tympanic plexus
- located on the surface of the promontory
54
oval window (of labyrinthine wall)
- "kidney" shaped opening into the vestibule of the inner ear, landmark of the labyrinthine wall
- occupied by the footplate of the stapes
55
round window (of the labyrinthine wall)
- circular opening into the first (basal) turn of the scala tympani of the cochlea
- landmark of labyrinthine wall
- located beneath oval window, in come shaped depression somewhat hidden by the promontory
- closed by thin secondary TM
56
prominence of lateral sac (of labyrinthine wall)
- the "bulge" in the medial wall of tympanic cavity caused by the close proximity of the lateral semicircular canal (scc)
57
prominence of facial canal (of labyrinthine wall)
- landmark of the labyrinthine wall, just superior to the oval window, home to the facial nerve
58
cochleariform process (of labyrinthine wall)
- curved lateral terminal of the tensor tympani muscle, the tendon of the tensor tympani emerges from the tensor tympani canal
- follows curve of cochleariform process to its insertion on the upper part of the manubrium of the malleus
59
carotid artery (of labyrinthine wall)
- one on either side of head and neck
- supplies brain with blood
- in close proximity to the anterior wall of the middle ear cavity
- the carotid canal which houses the carotid artery is separated from the anterior wall only by a thin plate of bone
60
mucous membrane
- ciliated lining of the middle ear cavity, continuous with that of nasopharynx and torus tubarius
61
tensor tympani
- larger of tympanic muscles
- completely housed within bony semi canal that runs nearly parallel and superior to the osseous framework of the auditory tube
- septum candlis musculotubarii seperates canal of this muscle from auditory tube (EuT)
- curved terminal of muscle is cochleariform process
- emerges from canal, sharp bend, conforms to curvature of cochleariform process and directed to insertion on upper part of manubrium of malleus
- contraction draws malleus medially and anteriorly
- force almost at right angles to direction of rotation of ossicular chain
- alone muscles increases tension of TM
62
stapedius
- much shorter than tensor tympani
- originates in bony canal running almost parallel to facial nerve canal on posterior wall of tympanic cavity
- nearly vertical, but tendon nearly horizontal
- muscle fibers originate from walls of canal and converge upon a tenson which emerges through a tiny aperture at apex of pyramidal eminence
- tendon attaches to stapes
- contraction exerts force on head of stapes and draws it posteriorly, perpendicular to movement of the ossicular chain
- stapedius and tensor tympani exert forces opposite to one another and perpendicular to primary rotational axis of ossicular chain
