Week 3B - vestibular pt 1 - thurs Jan 23

Question 1

the GTO location is the ___

Answer 1

tendon

Question 2

GTOS detect ____ and are innervated by ___

their 2 functions are

Answer 2

active tension
Ib afferents
protective mechnism
modulate force

Question 3

Go draw a muscle spindle

Question 4

describe hte mechanism/pathway that the spindle activates the motor neuron (Eg reflex)

Answer 4

the mechanism that activates the MN directly is the monosynaptic reflex

when the spundle spindle lengthens and is stretched Ia (primaries) (which are sentistive to stretch) activate teh MN and create the reflex

Question 5

why might it be beneficial for a sensory receptor liek a msucle spindle to have a special motor system to accomplish a refelx?

Answer 5

the msucle spindle is controlle dby the gamma system - this prevents the spindle from unlaoding during voluntary contractions and allows it to remain sensitve to stretch

Question 6

he stretch reflex is called the monosynaptic reflex because
the Ia afferent synapses onto the Ia interneuron prior to
synapsing onto the alpha motor neuron (True/False).
A) True B) False

Answer 6

False - monosyanptic is one synaose directly on MN

Question 7

are tehre receptors in the cartiliginous surfaces?

Answer 7

NO and not in sy=

Question 8

are teh receptors in synovial membranes/

Answer 8

no

Question 9

Join receptors respond to ___ of join movement and joint ____

Answer 9

limits of joint movement (extremes) and joint pressure (like swelling)

Question 10

joint receptors code____ meaning they respond to both __ and ___

Answer 10

ambigously for joint movements - respond to both flexion and extension

Question 11

IN terms of reflex activity joint receptors cause what effect on alpha MN and what does this suggest?

Answer 11

joint receptors cause a weak and infrequent effect on alpha MN

knee ligaments need to be rly stretched heavily to detect any EMG/AP activity - suffest protecive role for muscle regflexes

Question 12

what are teh 2 general types of sensory receptors (vestibular end organs) and tehir subcategories

Answer 12

Semicircular canals
- horizontal, ant, post.

Otolith organs
- saccule
- Utricle

Question 13

what do sesnosry recpetos care abotu int erms of the vesitbular system?

Answer 13

hwo the head is moving thru space

Question 14

what are the vesitbualr mechanoreceptors and what do they do?

Answer 14

The hair cells ,kinocillium and stereocillium transform Mechanical energy in to neural energy

Question 15

the hair cells (mechanoreceptors) in the vestibular system transform ___ energy into ___

Answer 15

mechanical into neural

Question 16

what is the apex of the hair cell called/

Answer 16

kinocillium

Question 17

what is the stair liek structure of hari cells called?

Answer 17

sterocilium

Question 18

what happens when the sterocilia are pushed TOWARDS kinocilium

Answer 18

the hair cell depolarizes and increases teh firing rate

Question 19

what happens when sterocilia are pushed AWAY from kinocilium?

Answer 19

hair cell hyperpolarizes and decreases the firing rate

Question 20

what happens ar rest to hair cells?

Answer 20

vestibular affernts inn hari cells continue to fire at a baseline firing rate due to leaky ion channels

Question 21

what type of motion semicircular canals detect?

Answer 21

angular acceleration

Question 22

wher is the endolymph foiund int he SSC?

Answer 22

int he canal

Question 23

wher are teh hair cells found in the SSC?

Answer 23

Cupula - hosue hari cells in the crista

Question 24

what happens to semicircular canal
a) at rest
b) accelerating
c) decelartion
d) at a constant velcotuy>

Answer 24

at rest - backgorund firing rates

accelerating - depolrization and incrased firing rate

deccelrating = hyperpolarization + decreased firing rates

constant velocity - returns to normal lakiness and baseline firing rates

Question 25

the _____ nerrve affernts are impacted in teh semicricualr canal during angular accelrations

Answer 25

8th

Question 26

shaking head no occurs in the ____ canal

Answer 26

horizontal

Question 27

nodding ehad yess occurs in the ____ cana;

Answer 27

anterior

Question 28

putting ur head to ur shoudler (side to side) occurs in the ____ canal

Answer 28

psoterior

Question 29

what leads to sensation of head rotaion?

Answer 29

the balance betwene elft and right excitation an dinhibition in semicircular canals

Question 30

True or flase head rotation causes the same endolymph fluid movement on both sides of teh head

Answer 30

false - causes opposite

Question 31

True or false - in both the right and left SSC dthe sterocilia are push towards the kiniocilum causing excitation/ incr firing rates/depolariation

Answer 31

FALSE - if stereociliar push toward kinocilium on right teh left will push them away causing inhibition oppostie on each side of head

Question 32

what is one of the main differnces between teh SSC and the otolith organs

Answer 32

Semicirc have endolymph = fluid and otolith has gel like substance (otolithic membrane)

Question 33

what do otolith organs detec?

Answer 33

linear acceleration + acceleration from gravity

Question 34

otoliths are smal ____ crystal embeded in ___

Answer 34

small calium carbonate crystals emebdded in gel like (gelatinous) material

Question 35

the utricle detects _____ and saccule detect ____ these are both typs of ??

Answer 35

utricle detects horizontal linear accerelation saccule detect vertical linear accelration both types of otolith rpgans

Question 36

for the otolith hair cells have ___ whcih __

Answer 36

cilia which rpojfect up into overlaying mebranf (otolithic mebrane) where small crystals are embedded

Question 37

what happens when head tilts or accelrates to teh otolith organs?

Answer 37

rgavity causes otoliths to sldie pulling sterocilia and casuing hair cell to depolarize

Question 38

what causes sitmualtion of otolith organs?

Answer 38

gravity or linear shear - linear accelration sesnitive