Vestibular System Flashcards
cutaneous receptors
mechanoreceptors that respond to deformation of skin surfaces - not to changes in temperature or pain
in superficial layers of the skin, steady pressure produces what type of cutaneous receptors
- slow adapting (SA)
- small receptive field (type 1)
in superficial layers of the skin, flutter/skin motion produces what type of cutaneous receptors
- fast adapting (FA)
- small receptive field (type 1)
in deep layers of the skin, skin stretch produces what type of cutaneous receptors
- slow adapting (SA)
- large receptive field (Type 2)
in deep layers of the skin, vibration; fine texture produces what type of cutaneous receptors
- fast adapting (FA)
- large receptive field (Type 2)
slow adapting
- fire continuously while stimulus is present
- monitor parameters that must be continuously evaluated
fast adapting (event detectors)
- stop firing if strength of a continuous stimulus is constant
- allows us to ignore constant unimportant information
- ** stops firing if stimulus stays the same
receptive field
- 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
tactile acuity
- 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
_______ has high tactile acuity whereas _____ has lower tactile acuity
- finger tips
- skin on low back or legs
joint receptors
- mechanoreceptors located in and around joints
- firing rate based on joint movement, muscle contraction or joint pressure
joint receptors are _______ to play a major role in joint position sense
unlikely
joint receptors play a ______ role in sensory information
- protective role
- limit detectors
vestibular system has _______ structures that house specialized sensory receptors or _________, including:
- five
- vestibular hairs
- 3 semicircular canals
- 2 otolith organs
3 semicircular canals
- anterior
- posterior
- horizontal
2 otolith organs
- utricle
- saccule
vestibular system tells us about the state of ________
our head relative to space
vestibular hair cells tells us ___________
information about our head position
vestibular sensory receptors =
vestibular hair cells
each hair cell contains
- 60 to 100 stereocilia (ascending from height)
- 1 single longer kinocilium
when hair cells are perfectly vertical it is in the ______
rest position
when hairs move to the right (or left) ________ occurs which ________
depolarization
increases firing rate
when the hairs move the other direction _______ occurs which _______
hyperpolarization
decreases firing rate
semicircular canals contain ______ and _____
ampulla
cupula
ampulla
- 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.
cupula
- vestibular hair cells embedded in cupula
- flow of endolymph displaces the cupula which will bend the vestibular hair cells
endolymph
- 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
semicircular canals ____ ______. They ______________
- work together
- sense rotation about 3 axes
_____ canals work together to signal head movement.
paired
a push and pull concept
the paired canals are:
- left and right horizontal canals
- left and anterior canal and right posterior canal
- left posterior canal and right anterior canal
otoliths
- thick jelly viscous material called the otolithic membrane
saccule
vertical acceleration and tilt
utricle
horizontal acceleration and tilt
vestibular hairs are embedded in the ______
otolithic membrane
on top of the membrane are _____. They are:
otoconia
- little rocks/ crystals on the otolithic membrane to give it weight
