Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

ANAT + PHYS (9610) > UNIT 7: Inner Ear > Flashcards

UNIT 7: Inner Ear Flashcards

(80 cards)

Start Studying
1
Q

the inner ear is comprised of

A

the organs of hearing and equilibrium

structurally linked

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

organs of hearing and equilibrium are innervated by

A

vestibulocochlear nerv CN VIII

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

systems of hearing and equilibrium consist of

A

osseous labyrinth and membranous labyrinth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

osseous labyrinth includes

A

semicircular canals, vestibule, cochlea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

membranous labyrinth consists of

A

semicircular ducts, utricle, saccule, cochlear duct

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

the human balance sys is comprised of

A

vestibular sys
vision
proprioception

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

CN VIII - vestibulocochlear has 2 components

A

vestibular and auditory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

describe the osseous labyrinth… fluid?… how many parts?

A

series of continuous spaces surrounded by bone

spaces are fluid filled - fluid is perilymph

has 3 parts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

3 parts of osseous labyrinth

A

semicircular canals (vestibular sys)
vestibule (vestibular sys)
cochlea (auditory sys)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

semicircular canals are 3 canals that for the …. names of the canals are…. each SCC is approx …

A

posterior portion of the osseous labyrinth

anterior, posterior, and lateral

2/3 of a complete circle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

each SCC has a dilated portion called an _____, SCCs enclose the ________ of the _______ labyrinth

A

ampulla

semicircular ducts

membranous labyrinth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Vestibule is the

A

middle dilated portion of the osseous labyrinth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

______ and _____ of the middle ear are located on the vestibule

A

fenestra vestibuli
fenestra cochleae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

vestibular aqueduct passes…

A

passes posterioinferiorly from the vestibule and opens on the posterior surface of the pertous bone

transmits endoymphatic duct and sac

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what does the vestibule house

A

the utricle and saccule of the membranous labyrinth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

cochlea is a ____ tube w approx ____ turns, its wide basal turn forms the _____

A

helical
2 3/4 turns
promontory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

the cochlea lies on its side in the ____, with its apex pointing _____

A

petrous bone
anterolaterally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

the cochlea encloses the

A

cochlear duct of the membranous labyrinth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

cochlea has a bony core called the _____, what passes thru this structure?

A

modiolus

cochlear portion of CN VIII and spiral ganglia pass thru it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

shelves of bone project laterally from the modiolus called the

A

osseous spiral laminae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

spiral laminae partially divide the cavity of the cochlea into 2 portions…

A

scala vestibuli anteriorly and scala tympani posteriorly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

at the apex of the cochlea, scala vestibulu and scala tympani communicate via a small opening called

A

helicotrema

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

division of the cochlea is completed by the

A

cochlear duct (scala media) of the membranous labyrinth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

scala vestibuli begins at

A

fenestra vestibuli (oval window), which is occupied by the footplate of the stapes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
scala tympani ends at
the fenestra cochleae (round window), which is closed by a secondary tympanic membrane
26
both scala vestibuli and tympani are filled w
perilymph aka osseous labyrinth
27
perilymph is
an extracellular fluid, similar in composition to plasma or cerebrospinal fluid
28
the membranous labyrinth is...
a series of connected ducts and sacs housed w/i and protected by the osseous labyrinth
29
membranous labyrinth is comprised of
semicircular ducts utricle saccule cochlear duct/scala media
30
ducts and sacs in the membranous labyrinth are filled w
endolymph
31
describe endolymph
more viscous than perilymph, similar composition to intracellular fluid
32
endolymph is produced by
stria vascularis in the cochlear duct moved toward the venous sys at the base of the brain by the endolymphatic duct
33
semicircular ducts are approx ___ of the diameter of the SC canals
1/4
34
each SCD has an _____ end, which contains ...
ampullated end contains a patch of sensory epithelium - the ampullary crest or crista ampullaris
35
crista ampullaris is
w/i the SCDs a patch of sensory epithelium sensory receptors for detecting rotational movement of the head contains hair cells
36
the hair cells of crista ampullaris have basal parts which synpase w
the vestibular nerve of CN VIII
37
crista ampullaris hair cells have stereocilia which project into a
tall, jelly-like mass called the cupula
38
@crista ampullaris: as the head rotates, endolymph moves opposite to the direction of rotation and...
pushes on the cupula bending the stereocillia
39
utricle communicates w
semicircular ducts
40
saccule communicates w the.... via the...
cochlear duct via the utriculosaccular duct
41
both the utricle and saccule contain..
a patch of sensory epithelium called the macula
42
utricle and saccule monitor the position of the.... and straight-line changes in ...
head, aka static equilibirum (lying down, sitting up etc) in speed and direction of head movements, aka linear acceleration (ex. walking, going up an elevator)
43
maculae is a
patch of epithelium w columnar supporting cells and scattered hair cells
44
hair cells in the maculae synapse w
fibres of the vestibular nerve of CN VIII
45
maculae: each hair cells has .... and the tips of the stereocilia are ...
many stereocilia protruding from its apex tips are embedded in overlying otolithic membrane
46
otolithic membrane of the maculae is...
a jelly like disc containing heavy crystals of calcium carbonate called otoliths
47
macula of the utricle is for ___ orientation, which indicates...
horizontal indicates head tilting and linear movement - forward, backward, sideways movement in a straight line
48
macula of the saccule is for ___ orientation, which indicates...
vertical orientation indicates head's upright position and linear movement - forward, backward, upward, downward movement
49
how is the otolithic membrane like a sac of marbles
So it will go in the opposite direction only when you are walking forward, back … think of dragging a sac of marbles behind you, hair cells will be bent behind you in opp direction But if you are tilting head down gravity will pull sac of marbles down, and the hair cells will bend down in the same direction
50
describe the cochlear duct/scala media
spiral tube housed in cochlea (25-35 mm) occupies the lateral portion - completes the division of the cochlea, started by the spiral laminae, into scala vestibuli and scala tympani
51
what 3 things form the "triangle" of the cochlear duct
basilar membrane vestibular membrane spiral ligament
52
basilar membrane is
floor of cochlear duct/scala media supprots the organ of hearing = organ of corti
53
vestibular membrane is
roof of the cochlear duct joins the basilar mem at the helicotrema
54
spiral ligament is
forms the lateral wall of the cochlear duct stria vascularis on surface of spiral ligament
55
organ of corti is...
a cellular structure along the length of the cochlear duct many cells serve a supportive function
56
hair cells of the organ of corti have stereocillia that project from....which are embedded in....
apex of hair cells the overhanging jelly-like tectorial membrane
57
hair cells of the organ of corti are innervated by
cochlear nerve of CN VII
58
movement of the fluid in the cochlear duct leads to
movement of the basilar membrane, bending the stereocillia and generating a nerve impulse
59
how many rows of inner hair cells on the organ of corti?
1
60
approx _____ IHCs on the medial side of the tunnel of corti
3500
61
how many stereocilia on each IHC? how are they arranged?
40 - arranged in parallel rows, dec in height towards the modiolus
62
how many rows of outer hair cells on organ of corti?
3 to 5
63
how many outer hair cells?
1200
64
how many stereocilia on OHCs? how are they arranged?
150 stereocilia per OHC arranged in the form of a V or W (base of letter points toward spiral lig) w dec height toward the modiolus
65
describe size/shape of OHCs
long and thin (cylindrical) tallest tips of OHC stereocilia are embedded in the tectorial membrane
66
describe size/shape IHCs
fat and round tips of IHC stereocilia are not embedded in the tectorial membrane
67
if the IHCs are not embedded in the tectorial membrane how do they move?
Outer hair cells are tall and thin, embedded in tectorial membrane, when the basilar membrane moves, the outer hair cells embedded move the tectorial membrane and this creates turbulence in the endolymp which makes the inner hair cells move We need the outer hair cells to help the inner hair cells fire
68
afferent fibres send sound information in the cochlea to the ...... and have cells bodies in the ....
CNS spiral ganglion
69
______ make up 95% of the nerve fibres in the cochlear nerve
Type I myelinated many type I fibres innervate a single IHC
70
____ make up 5% of nerve fibres in the cochlear nerve
type II unmyelinated one type II fibre innervates many OHCs
71
what are the 3 functions of the cochlea
transforms sound vibrations into neural impulses separates sounds according to their freq compresses amplitude of sounds
72
IHCs have most responsibility of....
hearing, that is sending afferent info regarding sound to CNS (function #1)
73
IHCs selectively respond to...
frequency (function #2)
74
OHCs are thought of as ....
amplifiers - they have the ability to change cell shape by receiving efferent fibres from the descending auditory nervous sys (function #3)
75
OHCs compensate for loss of energy w/i the ....
cochlea, improving the ear's sensitivity and sharpening ist freq selectivity for weak sounds
76
OHCs inc the movement of ...
the basilar membrane to amplify the activity of the IHCs
77
structure of the basilar membrane influences
its resonant properties and freq response characteristics - like a diving board narrow and stiff at base and wide and floppy at apex low freq sound cause vibration at the apex of the cochlea
78
what are the steps of hearing
Sound waves enter the ear through EAM TM vibrates from sound waves, sending vibrations to ossicles Ossicles amplify the sound vibrations and send them through the oval window to the cochlea of the inner ear The vibrations cause the fluid inside the cochlea to ripple, a travelling wave forms along the basilar membrane – the hair cells sitting on top of the basilar membrane ride the way As the hair cells move up and down the stereocilia on top of the hair cells bump against the tectorial membrane, causing them to bend When the stereocilia bend it opens channels that are at the tips of the stereocilia, chemicals rush into the cells creating an electrical signal Auditory nerve carries electrical signal to the brain
79
meniere's disease
too much endolymph leads to both hearing and vestibular disturbance (tinnnitis, fluctuating HL, rotatory vertigo) hearing returns to normal after attacks early in the disease process, as the disease progresses, residual hearing loss accumulates, and hearing loss spreads from low freq to high freq
80
benign paroxysmal positional vertigo (BPPV)
otolithic memebrane falls off utricle due to injury, age, drug effects - migrates toward semicircular ducts come to rest in a SCD (usually posterior) and creates a sensation of vertigo symptoms worsen if they rest on the cupula debilitating; always precipitated by a change in head position like rolling over in bed

ANAT + PHYS (9610) (21 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions