Anatomy of Inner Ear

Question 1

Innervation
Superior Vestibular N.

Answer 1

Anterior and horiztonal canal
Urticle and Part of saccule

Question 2

Innervation
Inferior Vestibular N.

Answer 2

Posterior canal
Part of saccule

Question 3

Endolymph

Answer 3

Fluid
Similar to CSF

Question 4

Perilympth

Answer 4

Semi-rigid, similar to interstitial fluid

Question 5

Bony Labyrinth

Answer 5

Embedded in temporal bone
Moves as one unit when skull/head moves

Question 6

Ossicles
3 Bones

Answer 6

Malleus
Incus
Stapes

Question 7

Where does the stapes connect?

Answer 7

Directly to the inner ear via the oval window

Question 8

• What is a Perilymph fistula?*

Answer 8

Auditory disturbance
Pressure disturbance

Question 9

Detection of Sound

Answer 9

Sound (vibration)
Auditory canal
Tympanic membrane
Ossicles
Oval window
Perilymph in cochlea
Hair cells
Excitation of cochlear nerve

Question 10

In what direction does the Cupula move in reference to endolymph fluid?

Answer 10

The same direction

Question 11

What direction does endolymph fluid move when the head is turning?

Answer 11

Opposite the side the head is turning

Question 12

Detection of Angular Motion
Turning head to the right
What is the direction of
- bony labyrinth
- endolymph
-cupula

Answer 12

BL: moves with head to the R
Endolymph: moves opposite, to the L
Cupula: deflects, moves to L

Question 13

Detection of Angular Motion
Turning head to the right
- What vestibular nerve is excited

Answer 13

Right side

Question 14

What are 3 semicircular canal orientation?

Answer 14

Anterior
Posterior
Hozitional

Question 15

3 semicircular canals
- Anterior presentation

Answer 15

~30º to sagittal plane

Question 16

3 semicircular canals
- Posterior presentation

Answer 16

~45º to sagittal plane

Question 17

3 semicircular canals
- Horiztonal presentation

Answer 17

~30º superior to transverse plane

Question 18

3 semicircular canals
- In reference to each other

Answer 18

Set at ~90º

Question 19

Canalith
- 3 semicircular canals detect what?

Answer 19

Rotation/Angular motion
Sensitive to certain motions

Question 20

Canalith
- what are the semicircular canals sensitive to?

Answer 20

Plane of motion
Quality of motion
Direction of motion

Question 21

Stimulation of Canals
- Horiztonal Canal

Answer 21

Rotation to same side in the horiztonal plane

Question 22

Stimulation of Canals
- Posterior Canal

Answer 22

Pitching back in ~45º plane

Question 23

Stimulation of Canals
- Anterior Canal

Answer 23

Pitching forward in ~30º plane

Question 24

“Push-Pull” Relationship
1. Right AC w/ …
2. Right PC w/ …
3. Left HC w/ …

Answer 24

1. L PC
2. L AC
3. R HC

Question 25

Contralateral Redundancy

Answer 25

Excitation on one side results in inhibition on the opposite side

Question 26

Otolith Organs include?

Answer 26

Utricle and Saccule

Question 27

Utricle and Saccule detect?

Answer 27

Linear motion Tilt U: horizontal motion S: vertical motion

Question 28

Striola - Internal Redundancy

Answer 28

Duplication of critical components or functions of a system with intention of increasing reliability of the system