Vestibular Part 1

Question 1

List the central vestibular pathway

Answer 1

8VVCROSS
cn 8
Vestibular Nuclei Ipsilateral
Vestibular Nuclei contralateral
cerebellum (to and from)
reticular formation
Occular muscles via CN III, IV, VI
Spinal cord (LVST and MVST)
Superior Sylvian gyrus and SI areas

Question 2

What 3 systems are involved in balance?

Answer 2

vision
somatosensory
vestibular
all 3 work together for us to keep our balance

Question 3

what are the two external forces in vestib system

Answer 3

vision and somatosensory

Question 4

What is the internal reference of vestib system

Answer 4

vestibular

Question 5

what is the main role of the balance system?

Answer 5

to allow us to interact and maintain contact with our surroundings in a safe and efficient manner

Question 6

what is ma de debarquement sysndrome (MdDS)

Answer 6

rare vestib disorder that makes you feel like you’re moving even when youre not. most common after travel, usually by boat

Question 7

what part of the peripheral vestib system happens with acceleration and deceleration

Answer 7

vestibular

Question 8

what part of the peripheral vestib system happens with standing still

Answer 8

somatosensory

Question 9

series of interconnected canals and cavities located in the petrous poriton of the temporal bone

Answer 9

labyrinth

Question 10

located medially and anteriorly in petrous apex

Answer 10

cochlea

Question 11

located laterally and posteriorly in petrous apex

Answer 11

vestibular

Question 12

how many sensory organs are there and where are they located

Answer 12

5 in each membranous labyrinth (10 total)
utricle and saccule macula
3 ampullae (cristae ampullaris)

Question 13

what and where are the vestibular ganglion

Answer 13

scarpa’s ganglion (cell bodies)
located in internal auditory canal
two divisions (superior (LSU) and inferior vestib nerve (PS))

Question 14

How many and what type of fibers are in vestib?

Answer 14

20,000
primarily bipolar afferent fibers

Question 15

what is the name of the afferent fiber that branches off of the inferior vestib nerve of CN VIII and attaches to the cochlea

Answer 15

vestibulocochlear ramus

Question 16

what is the accessory structure in the vestibular?

Answer 16

cupulla

Question 17

The vestibular system is ________ (more / less) effective when the head or body is still and ________ (more / less) active when the body is in motion.

Answer 17

less (use vision more here)
more (vestib main function here)

Question 18

Balance is dependent upon sensory information gathered from what three systems?

Answer 18

somatosensory/proprioception
vestibular
visual

Question 19

What are the two types of sensory structures in the vestibular system and what stimuli do they respond to?

Answer 19

crista ampullaris in SCC - angular acceleration - pitch, roll, yaw?
maculae in utricle and saccule (otolithic membrane)- linear acceleration and gravitational forces

Question 20

does kinocilium disappear after embryonic development in the vestibular system?

Answer 20

no, just in the cochlea

Question 21

why may we be able to regenerate hair cells and where?

Answer 21

in the vestibular system because the kinocilia is still present

Question 22

what are the type of hair cells in the vestib system?

Answer 22

Type 1 and type II

Question 23

which vestibular hair cell is flask shaped with a large nerve innervating directly by afferent fibers?

Answer 23

type I

Question 24

which vestibular hair cell is cylindrical and innervated directly by efferent fibers

Answer 24

type II

Question 25

what produces endolymph in vestibular system?

Answer 25

dark cells

Question 26

how are kinocilia oriented in the horizontal canal

Answer 26

toward the utricle

Question 27

how are the kinocilia oriented in the superior/posterior canals

Answer 27

away from the utricle

Question 28

What fluid movement causes excitation in horizontal canal?

Answer 28

fluid movement from the semicircular canal side and toward the utricle (hits smaller stereocilia first)

Question 29

what fluid movement causes inhibition in horizontal canal?

Answer 29

fluid movement from the utricle toward the canal (hits kinocilia first)

Question 30

what fluid movement causes excitation in ant/post canals?

Answer 30

fluid movement from the utricle toward the canal

Question 31

what fluid movement causes inhibition in ant/post canals?

Answer 31

fluid movement from the semicircular canals toward the utricle

Question 32

what are the otolithic structures

Answer 32

utricle and saccule

Question 33

what plays a large role in postural control and senses change in orientation in respect to gravity (moving forward in a car)

Answer 33

utricle

Question 34

what is in the otolithic membrane to give it density

Answer 34

otoconia

Question 35

what are embedded in the otolithic membrane

Answer 35

stereocilia and kinocilia

Question 36

what detects linear acceleration and gravitational forces

Answer 36

maculae (utricle - horizontal saccule - verticle)

Question 37

calcium carbonate crystals mixed with a protein matrix

Answer 37

otoconia

Question 38

small grain- or rice-shaped particles with a density that allows the utricle to respond transiently to linear acceleration and in a more practical fashion to head tilt

Answer 38

otoconia

Question 39

tilt head left =

Answer 39

inhibitory

Question 40

tilt head right =

Answer 40

excitatory

Question 41

imaginary line through axis of each maculae which hair cells are organized

Answer 41

striola

Question 42

axis for polarization allowing for complex stimulation patterns

Answer 42

striola

Question 43

this allows for a complex multidirectional pattern of responses

Answer 43

the alignment of hair cells around the striola

Question 44

kinocilia are ____ striola in utricle

Answer 44

toward

Question 45

kinocilia are ____ striola in saccule

Answer 45

away

Question 46

primarily registers vertical movement, like going up in an elevator

Answer 46

saccule

Question 47

how is the saccule connected to the utricle and semicircular canals?

Answer 47

vestibular aqueduct