Ch 10.2: Vestibular Apparatus & Eq

Question 1

Parts of the VA

Answer 1

1) otolith organs (utricle & saccule) - linear acceleration

2) semicircular canals - rotational acceleration

Question 2

Inner Ear parts

Answer 2

1) bony labyrinth (surrounding membranous labyrinth)
2) perilymph - fluid (between bony/memb laby)
3) endolymph - fluid in memb laby

Question 3

Endolymph has an unusually high

Answer 3

[K+] = depolarization ready

Question 4

What are stereocilia?

Answer 4

modified epithelial cells for sensory reception - not true cilia

Question 5

kinocilium

Answer 5

true cilia - modified epithelial cells for sensory reception

Question 6

Stereocilia bending toward kinocilium results in ___

Answer 6

the opening of K+ channels, depolarization, release of NT to depolarize vestibulocochlear nerve

Question 7

Stereocilia bending away from kinocilium results in ___

Answer 7

hyperpolarization of sensory dendrites

Question 8

Stereocila and kinocilium system helps to ___

Answer 8

code for detection of direction

Question 9

Utricle = linear acceleration in the ____ plane

Answer 9

horizontal

Question 10

saccule = linear accel in the ____ plane

Answer 10

vertical

Question 11

What houses hair cells?

Answer 11

macula

Question 12

Where do stereocilia embed?

Answer 12

in the gelatinous otolithic membrane

Question 13

The otolithic membrane contains ____

Answer 13

stereocilia and crystals of Ca carbonate (otoliths)

Question 14

At the base of each semicircular canal duct is the

Answer 14

ampulla

Question 15

Semicircular ducts are filled with

Answer 15

endolymph

Question 16

Where do hair cells of semicircular canals embed?

Answer 16

in crista ampullaris (stereocilia stuck in gelatinous cupula)

Question 17

What happens in the semicircular canals when you rotate your head?

Answer 17

endolymph circulates, pushes the cupula to bend the hair cells

Question 18

Neural Pathways

Answer 18

vestibulocochlear nerve —> vestibular nuclei (medulla & cerebellum) —> oculomotor area of brain stem (controls eye movements) —> down spinal cord (adjust body movements)

Question 19

When the body is spinning, what happens in the eyes?

Answer 19

eye movements are toward the opposite direction of spin to maintain a fixation point

Question 20

What happens when the body stops spinning?

Answer 20

the cupula is bent by fluid inertia, with eye movements still affected

Question 21

Nystagmus

Answer 21

when jerky eye movements produced after spinning

Question 22

Vertigo

Answer 22

loss of equilibrium from nystagmus