Vestibular System

Front 1

What is inside the semicircular canals?

Back 1

Ampullae that contain crista.

Front 2

What the do ampullae which contain crista respond to?

Back 2

angular acceleration(endolymph)

Front 3

What are crista? What do they do?

Back 3

simple modified hair cells that detect movement of the endolymph.

Front 4

Where are the saccules found?

Back 4

at the base of the semicircular canals.

Front 5

What contains modified hair cells that respond to movement of the body up & down?

Back 5

Macula.

Front 6

Where is the maculae located? What does it do?

Back 6

In the utricle. It detects changes in gravitational forces & linear acceleration. = horizontal.

Front 7

T/F: macula of the saccule responds to vertical movement.

Back 7

true!

Front 8

T/F: maculae of the utricle detect changes in horizontal movement.

Back 8

true!

Front 9

T/F: macula of the saccule respond to horizontal movement.

Back 9

false! the maculae of the utricle does!

Front 10

at the end of the semicircular canal it gets a little larger. what is this enlarged structure called?

Back 10

ampula cristi. or crista ampulla. (seen both ways)

Front 11

what's the purpose of the calcium carbonate crystals?

Back 11

they provide mass.

Front 12

what part of the hair cells are in contact with the otoliths embedded in the gelatinous mass?

Back 12

the tips of the hair cells.

Front 13

the oval and round windows have what kind of frequency?

Back 13

high frequency.

Front 14

if you shake a rope slowly you will get higher frequency closer or farther to your hand?

Back 14

Farther.

Front 15

if you shake a rope fast, where is the higher frequency located? closer or farther from hand?

Back 15

closer.

Front 16

where is the location of the cell bodies of the sensory axons that innervate the hair cells of the ampula crista?

Back 16

superior ganglia

Front 17

the combo of which axons cells form the vestibular nerve? where do they enter?

Back 17

the inferior and superior ganglia. they enter the CNS at the cerebellopontine angle btw the inferior cerebellar peduncle & spinal trigeminal tract.

Front 18

where is the location of the cell bodies of the sensory axons that innervate the hair cells of the ampula crista and maculae?

Back 18

inferior ganglia

Front 19

vestibular nerve fibers bifurcate into what type of projections within the vestibular nuclei?

Back 19

short ascending and long descending projections.

Front 20

T/F: some vestibular fibers go directly to the cerebellum.

Back 20

true!

Front 21

the lateral gaze is controlled by what?

Back 21

PPRF (also it needs CN 3 & 6)

Front 22

the MLF connects which CN?

Back 22

CN 3,4,6

Front 23

how are the vestibular nuclei arranged? and what are they called?

Back 23

into two longitudinal columns. a lateral and a medial column.

Front 24

where are the vestibular nuclei located?

Back 24

extend from just rostral to the hypoglossal nucleus to just below the abducens nucleus.

Front 25

the lateral column contains which nuclei?

Back 25

inferior vestibular nucleus (beings at the medulla medial to the accesory cunate nucleus), lateral vestibular nucleus (runs the dorsoventral length of hte nucleus, contains large cells) & superior vestibular nucleus(located dorsal and rostral to the lateral vestibular nucleus at the lateral angle of the 4th ventricle, has small to medium cells)-

Front 26

which nuclei does the medial column of the vestibular nuclei contain?

Back 26

just the medial vestibular nucleus and runs the dorsalventral length of the nucleus, contains small and medium cells

Front 27

what happens when pressure builds over the motor strip? (wordy)

Back 27

Pressure build over motor strip: knock out language, motor strip, sensory strip to opp side of body.
The next nucleus that would function would be? Nuc involved in flexion found in brain stem at the level of sup coliculus = red nucleus. Takes over bc motor stip can’t. DECORTATE posture, limbs come up to chest, flexed.
-after extension/red nucleus is death. Then phrenic nucleusdeals with diaphram.

Front 28

where do primary vestibular fibers project to?

Back 28

all vestibular nuclei and the interstitial nucleus of the vestibular nerve.

Front 29

where do the semicircular canals project to?

Back 29

the superior and rostral part of the medial nucleus.

Front 30

where does the utricle project to?

Back 30

the lateral part of the medial nucleus and the medial part of the inferior nucleus and inferior part of the superior nucleus.

Front 31

where's the saccule? what does it bifurcate into?

Back 31

lateral portion of the inferior nucleus. bifurcates into: ascending & descending.

Front 32

T/F: the saccule bifurcates into ascending and descending.

Back 32

true. ascending: superior, medial and lateral vestibular nuclei. descending: to the inferior and caudal part of the medial nucleus.

Front 33

T/F: The cerebellar projections help with gravity.

Back 33

true.

Front 34

what are the fibers called that project directly to the crebellar cortex?

Back 34

mossy fibers (via the juxtirestiform body)

Front 35

what's the juxtirestiform body?

Back 35

portion of the inferior cerebellar peduncle

Front 36

T/F: some cells project directly to the cerebellar cortex to the floccular-nodular portions of the cerebellum.

Back 36

true.

Front 37

T/F: half of the vestibular nuclei send projections to the cerebellar cortex.

Back 37

false! ALL vestibular nuclei do!

Front 38

the anterior and lateral semicircular canals, saccule and utricle all send direct projections to what side of the flocculus of the cerebellum?

Back 38

ipsilateral

Front 39

T/F: secondary projections include: cerebellum, motor cranial nuclei, and spinal cord.

Back 39

true.

Front 40

T/F: vestibulocerebellar secondary projections are more numerous that vestibular nerve.

Back 40

true.

Front 41

where does the vestibulocerebellar send it's projections to?

Back 41

to the cortex of the nodulus, uvula & flocculus (bilaterally) and to the fastigal nuclei (mainly ipsilaterally).

Front 42

MLF: all vestibular nuclei send crossed & uncrossed projections here. T/F.

Back 42

true.

Front 43

what does MLF stand for?

Back 43

medial longitudinal fasciculus.

Front 44

who did juliet fall in love with?

Back 44

romeo.

Front 45

romeo likened juliet to which astronimical object?

Back 45

the sun.

Front 46

ascending MLF goes where?

Back 46

abducens, oculomotor, trochlear nuclei & also to interstitial nucleus of Cajal (one of the accessory oculomotor nuclei)

Front 47

MLF also contains fibers from the pontine reticulospinal, tecto spinal and interstitiospinal tracts for controlling what?

Back 47

conjugate eye movements(possibly to the VPL of the thalamus and from there to the interparietal sulcus of the cortex)

Front 48

which tract controls conjugate movement of the eye's incorporation wtih the paramedian pontine reticular formation (PPRF)?

Back 48

ascending MLF

Front 49

what does PPRF stand for? what does it do?

Back 49

paramedian pontine reticular formation. it receives and sends projections from the oculomotor nuclei and the vestibular nuclie

Front 50

where does the medial vestibulospinal projections descend in?

Back 50

the contralateral and ipsilateral MLF (along with fibers from the interstitial nucleus of Cajal, pontine reticular formation & the supra optic nucleus---one of hte pretectal nuclei) to cervical and most throaciclevels (terminating on laminas VII and VIII)

Front 51

the medial vestibulospinal projections controlls what?

Back 51

head and neck muscles for walking and movement of the head to coordinate it with the eye movement.

Front 52

medial vestibular projections have a direct inhibitory role on which neurons?

Back 52

alpha and gamma-motor neurons (inhibit flexor muscle tone, produce extensor muscle tone as appropirate for the situation)

Front 53

the lateral vestibulospinal tract conveys info for what?

Back 53

for extensor muscles tone and extensor spinal reflexes and tone (posture; also think of it as controlling antigravity muscles)

Front 54

the rubrospinal tract controls what?

Back 54

flexors of spinal reflexes and tone.

Front 55

what is key sentence for vestibular systems?

Back 55

ipsilateral is dominant!