anatomy

Question 1

what do cilia in semicircular canals detect?

Answer 1

skull angular acceleration/deceleration

not constant velocity

Question 2

Within the ampulla of each semicircular is the tallest cilia called?
Movement toward is +/-?
Movement away s +/-?

Answer 2

kinocilium
toward - excitatory
away - inhibitory

Question 3

cochlea and vestibular organ make up?

Answer 3

labyrinth

Question 4

what issues are related to the cochlea?

Answer 4

1. Hearing loss
2. Tinnitus
3. Pressure in the ear
4. otalgia – pain
5. otorrhea - discharge

Question 5

membranous semicircular canal size?

Answer 5

0.25mm in diameter, capillary in size, very tiny

Question 6

describe how R Ant/ L Post semicircular canals are functional pairs?

Answer 6

If rotate head L by 45 deg, R Ant and L Post canals are in sagittal plane.
When head nods- one is excitatory and other is inhibitory

Question 7

• anterior/posterior canal kinocilium away from utricle

- displacement is excitatory for ant/post canals; inhibitory for the horizontal canal

Answer 7

Utriculofugal cupular displacement

Question 8

• horizontal canal kinocilium toward utricle

- excitatory for the horizontal canal; inhibitory for the anterior/ posterior canal

Answer 8

Utriculopetal cupular displacement

Question 9

how does alcohol cause dizziness?

Answer 9

Cupula dome structure containing cilia when healthy has the specific gravity is same as surrounding endolymph;
alcohol is lighter than endolymph and diffuses into cupula; cupula is lighter and make head feel like rotating

Question 10

what may disturb health of cupula?

Answer 10

trauma, intoxication, BPPV

Question 11

what vestibular system part detects

• linear acceleration
• gravitational force
• head location in space- Head tilts and Translation of head in space
• part of postural control

Answer 11

Otolith organs (utricle and saccule)

Question 12

Cilia is on floor of what otolith organ detect horizontal plane, eg. speeding in car

Answer 12

utricle

Question 13

Cilia is on medial wall of what otolith organ

detect vertical plane, eg. going up elevator

Answer 13

saccule

Question 14

• calcium carbonate rocks in otolith organs
  that can get loose from their membrane
• attached to cilia pulled on by gravity

Answer 14

Otoconia

Question 15

problems with otoconia - feeling? acute disturbance

Answer 15

Pulsion, loss of balance, feel pushed/shoved in one direction

Question 16

problems with otoconia - feeling? go into semicircular canals

Answer 16

vertigo, BPPV

Question 17

when does otoconia break away more?

Answer 17

older age, female (especially if osteoporosis/osteopenia)

Question 18

• located in endolymph of ampulla of semicircular canal and utricle
• help break down loose otoconia
• Responsible for calcium homeostasis and potassium transport

Answer 18

Dark cells

Question 19

Decreased number of these in Meniere’s disease and labyrinthitis which may account for increased case of BPPV?

Answer 19

dark cells

Question 20

how many vestibular organs do we have?

Answer 20

10

a. 3 semicircular canals
b. Utricle – horizontal plane
c. Saccule – vertical plane

Question 21

when sleeping, what canals do otoconia typically travel into?

Answer 21

posterior and horizontal canals are dependent

Question 22

recurring BPPV may be due to

Answer 22

• Increase loose otoconia

- Decrease in dark cells to help degrade otoconia