chapter17 part9 p.593-596 equilibrium

Question 0

What are the 3 semicircular ducts?

Answer 0

anterior, posterior, lateral

Question 1

What are the sensory receptors in the semicircular ducts that respond to rotational movements of the head?

Answer 1

hair cellls

Question 2

The semicrcular ducts are continuous with what?

Answer 2

utricle

Question 3

each semicircular duct contains ________, an expanded region that contains the receptors

Answer 3

ampulla

Question 4

region in the wall of the ampulla that contains the receptors

Answer 4

crista ampullaris/crista

Question 5

cupula

Answer 5

each crista ampullaris is bound to this- gelatinous structure that extends the full width of the ampulla

Question 6

receptors in the cristae ampullares are what?

Answer 6

hair cells

Question 7

Free surface of each hair cell supports 80-100 what?

Answer 7

long stereocilia

Question 8

Each hair cell in the vestibbule contain a single what?

Answer 8

kinocilium

Question 9

At a crista, kinocilia and sterocilia of the hair cells are located how?

Answer 9

embedded in the cupula

Question 10

describe the movements that each semicircular ducts are responsible for

Answer 10

lateral semicircular duct- horizontal rotation “no”
anterior duct- nodding yes
posterior duct- tilting head side to side

Question 11

endolymphatic duct ends in a closed cavity called

Answer 11

endolymphatic sac

Question 12

endolymphatic sac is in the subarachnoid space surrounded by what?

Answer 12

capillary network

Question 13

portion of the cochlear duct secrete what continuously?

Answer 13

endolymph

Question 14

excess fluid returns to the general circulation at the what?- in terms of endolymph

Answer 14

endolymphatic sac

Question 15

endolymphs are removed by what 2 mechanisms?

Answer 15

combination of active transport and vesicular transport

Question 16

Hair cells of the utricle and saccule are clustered in oval structure called what

Answer 16

maculae

Question 17

macula in utricle is sensitive to what?

Answer 17

changes in horizontal movement

Question 18

macula in the saccule is sensitive to what?

Answer 18

changes in vertical movement

Question 19

The hair cells of utricle and saccule are embedded in gelatinous_______ membrane. describe this membrane

Answer 19

otolithic- surface contains desnely packed calcium carbonate crystals

Question 20

what are calcium carbonate crystals called

Answer 20

otoliths/ear stones

Question 21

\accelerating forward has similar effect as

Answer 21

tilting your head back- otoliths lag behind

Question 22

hair cells of the vestibule and semicircular ducts are monitored by sensory neurons located in adjacent what?

Answer 22

vestibular ganglia

Question 23

sensory fibers from vestibular ganglia for vestibular branch of what nerve?

Answer 23

vestibulocochlear nerve VIII

Question 24

The vestibulocochlear nerve innervate neurons within pair of what at the boundary between pons and medulla oblongata?

Answer 24

vestibular nuclei

Question 25

what are 4 functions of vestibular nuclei?

Answer 25

1. integrating sensory info about balance and equilibrium that arrives from both sides of the head 2. relaying info from vestibular complex to cerebellum 3. relaying info from vestibular complex to cerebral cortex- conscious sense of head position and mvmt 4. sending commands to motor nuclei in brain stem and spinal cord

Question 26

instructions from vestibular nuclei descend where?

Answer 26

vestibulospinal tracts

Question 27

automatic movements of the eys in response to sensation of motion are directed by what of the midbrain

Answer 27

superior colliculi

Question 28

what is the function of the superior colliculi?

Answer 28

attempts to keep gaze focused on a specific point in space despite changes in body position and orientation

Question 29

nystagmus

Answer 29

condition where individuals have short jerky movement of eyes even though they remain stationary. they have trouble controlling their eye movements