Vestibular System

Question 1

cutaneous receptors

Answer 1

mechanoreceptors that respond to deformation of skin surfaces - not to changes in temperature or pain

Question 2

in superficial layers of the skin, steady pressure produces what type of cutaneous receptors

Answer 2

• slow adapting (SA)

- small receptive field (type 1)

Question 3

in superficial layers of the skin, flutter/skin motion produces what type of cutaneous receptors

Answer 3

• fast adapting (FA)

- small receptive field (type 1)

Question 4

in deep layers of the skin, skin stretch produces what type of cutaneous receptors

Answer 4

• slow adapting (SA)

- large receptive field (Type 2)

Question 5

in deep layers of the skin, vibration; fine texture produces what type of cutaneous receptors

Answer 5

• fast adapting (FA)

- large receptive field (Type 2)

Question 6

slow adapting

Answer 6

• fire continuously while stimulus is present

- monitor parameters that must be continuously evaluated

Question 7

fast adapting (event detectors)

Answer 7

• stop firing if strength of a continuous stimulus is constant
• allows us to ignore constant unimportant information
• ** stops firing if stimulus stays the same

Question 8

receptive field

Answer 8

• area of skin surface over which stimulation results in change in rate of action potential
• depends on branching characteristics of afferent within skin, density of afferent fibers

Question 9

tactile acuity

Answer 9

• extent to which one can discern small structural details in objects that touch the skin
• related to several factors, including receptive field size and receptor density
• assess using the 2 point discrimination test

Question 10

_______ has high tactile acuity whereas _____ has lower tactile acuity

Answer 10

• finger tips

- skin on low back or legs

Question 11

joint receptors

Answer 11

• mechanoreceptors located in and around joints

- firing rate based on joint movement, muscle contraction or joint pressure

Question 12

joint receptors are _______ to play a major role in joint position sense

Answer 12

unlikely

Question 13

joint receptors play a ______ role in sensory information

Answer 13

• protective role

- limit detectors

Question 14

vestibular system has _______ structures that house specialized sensory receptors or _________, including:

Answer 14

• five
• vestibular hairs
• 3 semicircular canals
• 2 otolith organs

Question 15

3 semicircular canals

Answer 15

• anterior
• posterior
• horizontal

Question 16

2 otolith organs

Answer 16

• utricle

- saccule

Question 17

vestibular system tells us about the state of ________

Answer 17

our head relative to space

Question 18

vestibular hair cells tells us ___________

Answer 18

information about our head position

Question 19

vestibular sensory receptors =

Answer 19

vestibular hair cells

Question 20

each hair cell contains

Answer 20

• 60 to 100 stereocilia (ascending from height)

- 1 single longer kinocilium

Question 21

when hair cells are perfectly vertical it is in the ______

Answer 21

rest position

Question 22

when hairs move to the right (or left) ________ occurs which ________

Answer 22

depolarization

increases firing rate

Question 23

when the hairs move the other direction _______ occurs which _______

Answer 23

hyperpolarization

decreases firing rate

Question 24

semicircular canals contain ______ and _____

Answer 24

ampulla

cupula

Question 25

ampulla

Answer 25

• dilation at end of each canal
• contains a crista (ridge of tissue)
• upper surface of crista contains the vestibular hair cells

surrounds sensory receptors that are responsible for movement related sensory experiences like spatial awareness and pressure change. Ampullae (the plural of ampulla) are located throughout the semicircular canals of the inner ear.

Question 26

cupula

Answer 26

• vestibular hair cells embedded in cupula

- flow of endolymph displaces the cupula which will bend the vestibular hair cells

Question 27

endolymph

Answer 27

• fluid travels through the canals within the ampula

- when head moves, the endolymph moves and pushes the cupula which then changes the alignment of the hair cells

Question 28

semicircular canals ____ ______. They ______________

Answer 28

• work together

- sense rotation about 3 axes

Question 29

_____ canals work together to signal head movement.

Answer 29

paired

a push and pull concept

Question 30

the paired canals are:

Answer 30

• left and right horizontal canals
• left and anterior canal and right posterior canal
• left posterior canal and right anterior canal

Question 31

otoliths

Answer 31

• thick jelly viscous material called the otolithic membrane

Question 32

saccule

Answer 32

vertical acceleration and tilt

Question 33

utricle

Answer 33

horizontal acceleration and tilt

Question 34

vestibular hairs are embedded in the ______

Answer 34

otolithic membrane

Question 35

on top of the membrane are _____. They are:

Answer 35

otoconia

- little rocks/ crystals on the otolithic membrane to give it weight